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The cover image was created by the transcriber and is placed in the public domain.

MODERN COTTON SPINNING MACHINERY,

ITS PRINCIPLES AND CONSTRUCTION.

BY

JOSEPH NASMITH,

ASSOCIATE INSTITUTION MECHANICAL ENGINEERS,
MEMBER MANCHESTER ASSOCIATION OF ENGINEERS, ETC.

WITH TWO HUNDRED AND THIRTY-TWO ILLUSTRATIONS.

MANCHESTER:
JOSEPH NASMITH, 4, Arcade Chambers, St. Mary’s Gate;
JOHN HEYWOOD, Ridgefield and Deansgate.
LONDON:
E. & F. N. SPON, 125, Strand; and 12, Cortlandt Street, New York.
1890.
[COPYRIGHT.—ALL RIGHTS RESERVED.]

PREFACE.

In submitting the following pages to the judgment of the public, the Author does not pretend to have written an exhaustive treatise. This would require a volume much larger than the present. It has rather been his aim to treat a branch of the subject thoroughly, which has hitherto had scant justice done to it. While the market is flooded with books detailing the rules by which speeds are calculated, and the necessary wheel changes made, those dealing with the construction of the machinery employed are few in number. This is the more singular, because England is, beyond doubt, the true mother of this department of mechanics, and to-day her textile machinists head the lists alike for excellence of production and fertility of invention.

Since the issue of the late Mr. Evan Leigh’s “Science of Modern Cotton Spinning”—comparatively a long time ago—no book has appeared which treats the subject from the machinist’s point of view. The well known book of Mr. Richard Marsden, “A Handbook of Cotton Spinning,” as its name implies, deals more with the operation than the machinery, although the latter is described in considerable detail. In the present work, while it has been impossible to avoid saying something of spinning, the enunciation of the principles on which the machinery is constructed forms its raison d’être. On the Continent, more than one ponderous treatise has been published, which possess the peculiarity of foreign technical works in the disproportionate way in which the small details are treated. While this is valuable from the professorial point of view, it is apt to be prejudicial in actual practice, because the operation of these details varies considerably at different times. The avoidance of pedantry is very essential in any book dealing with practical work, and with this in view, the Author has endeavoured, while fully considering every principle involved, to do so in a plain manner, which will be readily understood. It has rather been the aim to suggest the inferences to be drawn than to dogmatically state inflexible rules.

The whole of the machines have been considered fully, and the most important modifications described. The preparation of the drawings has been a long labour, but the Author believes they have not hitherto been so fully given in any English work. In order to keep the book within bounds, it has been almost rigidly confined to a consideration of the art of textile mechanics as applied to the spinning of cotton to-day. It is believed that the book will provide an accurate account of the state of present knowledge, and will be valuable for that reason.

It should be distinctly understood that the mention of any machinist does not imply any approval or otherwise of his particular appliance, but is simply given in order to identify the maker of it, which it is only fair to do. The Author’s opinions can be easily gathered, but it is no part of the scheme to enter into controversy about different methods, or to make the book a treatise on comparative textile mechanics.

The Author desires to thank all those firms who have aided him by the loan of drawings, or in other ways. Without this aid the labour involved would have been largely increased. Thanks are due to Signor Alfredo Galassini and the Director of the Unione Tipografico-Editrice of Turin for permission to reproduce some of the drawings relating to Messrs. Platt Brothers and Co.’s mule, which will be found in Chapter [XI]. These had appeared in the “Enciclopedia Delle Arti E Industrie,” and were so much in accord with the treatment the Author had resolved to give that machine, that the permission to use them was of great service. The special thanks of the Author are also due to Mr. B. A. Dobson for the permission to reproduce two photographs of a lap, given in Chapter [VI]., and other drawings from his pamphlet on “Carding.” In conclusion, before leaving the book to the indulgent judgment of his readers, the Author wishes to say that the proofs have been read by gentlemen conversant with the whole of the details, and every care has been taken to make it at once accurate and instructive.

TABLE OF CONTENTS.

ERRATA.

The reader is requested to make the alterations enumerated below at once in order to prevent any misunderstanding.

On page 51, end of line 23, for “it” read “is.”

On page 66, line 15, for “Fig. 51” read “Fig. 52.”

On page 162, third line from bottom, for “n = b - 21” read “n = 21 - b.”

On page 163, line 7, for “n = 250 - 2 (250÷40)” read “n = - 250 - 2 (250÷40).”

On page 165, second line from bottom, for “G” read “E.”

On page 210, line 3, for “B” read “D.”

On page 212, end of last line, for “fallen” read “faller.”

On page 267, line 4, for “straps” read “shafts.”

The author is fully conscious of many shortcomings, which are inevitable in a task of this magnitude, but he believes that something has been done to formulate present knowledge and practice. Any suggestions of improvements or enlargements will be gratefully received, so as to enable future issues to be more valuable and useful.

CHAPTER I.
INTRODUCTORY.

(1) The rapid growth of the cotton trade is in no small degree due to the exertions and ingenuity of the engineers and machinists who have devoted themselves to the subject. It is remarkable how few of the later inventions, at any rate, are those of persons actually engaged in the operations of spinning or weaving. It is quite true that James Smith, of Deauston, forms a conspicuous exception, and that many others could be also named who were at once manufacturers and mechanicians, but the general fact is as stated. To-day, the spinner, who is in a difficulty requiring a mechanical solution, turns the whole matter over to the machinist, who puzzles it out without, in many cases, getting his due reward. It is, however, a general practice for machinists to originate improvements, and the competition in this respect is so keen, that a spinner is never at a loss for a choice of appliances.

(2) In the early part of the century it was no uncommon thing to find textile machines made in a workshop where engines, machine tools, and other forms of machinery were also constructed. For about the last forty years this practice has ceased, and it is now the universal custom to make textile machines only, in any works where they are produced. This practice has led to a subdivision, not only of labour, but of procedure, which enables good results to be attained. The machine of to-day, although not absolutely, is comparatively, cheaper, and is constructed in a way that even thirty years ago would have been deemed impossible. When the author was an apprentice, about twenty years since, the fitting of cotton machinery was a byeword to the engineer and tool maker. To-day, it would be difficult to find more accurate workmanship or sounder construction in any machine of whatever kind.

(3) This is a matter of more importance than might be supposed. The cotton spinning machine making trade in England is a very extensive one, finding employment in Lancashire alone for not less than 25,000 men and boys. This does not include the large number of persons employed in the various businesses which are allied to it, such as spindle and card clothing manufactories. The field for spinning machines is ever enlarging, the possible extent of the cotton industry being enormous. The number of spindles at work in Great Britain exceeds 44,000,000; on the Continent the number is about 23,800,000; in the United States 14,500,000; and in India and Japan it exceeds 3,000,000. These figures, which are approximate only, give a grand total of 85,300,000 spindles, which may all be said to have sprung into being during the present century. Assuming the value of a mill to be equal to 21 shillings per spindle in England, the fixed capital embarked in this branch of the trade alone is £44,220,000. If the very moderate amount of 20 per cent be added to this for working capital, the sum invested in cotton spinning concerns in this country is not less than £53,000,000. The cost per spindle in other countries is much in excess of the amount stated above, being in many cases doubled. In the United States the cost of a fully equipped spinning-mill ranges from 40 to 42 shillings per spindle, and the capital needed for working is also greater than in this country. On the Continent, and in India, the cost per spindle will be less than in America, but the working expenses are also higher than in Great Britain. In thus stating the facts it is impossible to accurately fix the capital employed, but it will probably approach in the aggregate £150,000,000 for spinning mills alone.

(4) The foregoing figures, which are very briefly put, are sufficient to show the magnitude of the industry for which spinning machinists cater. But there is another aspect of the question which is noteworthy, and illustrative of the effect of the work of machine makers. This is the large increase in the productive capacity of the machinery. The production of a self-acting mule in 1835 is given in the following statement, issued by the eminent firm of Sharp, Roberts and Co., and extracted from Dr. Ure’s work on “Cotton Spinning.”

“Statement of the quantity of Yarn produced on Messrs. Sharp, Roberts & Co.’s self-acting mules in twelve working hours, including the usual stoppages connected with spinning, estimated on the average of upwards of 20 mills:—

This statement is dated December 23rd, 1834, so that it may fairly serve as a basis of comparison, assuming the number of turns of yarn to be in each case the same. Testing the advance by taking the production of 32’s, as stated above, the amount spun per spindle in a working week of 50¹⁄₂ hours—its present duration—would be 18²⁄₃ hanks. Mules at that period were only made 400 to 500 spindles long. To-day they contain over 1,200 spindles, and produce of 32’s 32¹⁄₂ hanks per spindle. This is an increase of 60 per cent.

(5) The increase of production has not, however, required a larger number of workpeople to obtain. On the other hand, fewer persons are needed to attend to the long mules named than were formerly required for less than half the number of spindles. The effect of this is seen in the decreased margin between cotton and yarns, which is very striking. The average price of 30’s twist yarn in 1832 is stated in Dr. Ure to be 12·7d. per lb., and of cotton 7·1d., leaving a margin of 5·6d. At the time of writing the price of 32’s twist is 8¹¹⁄₁₆d., and of cotton 6⁹⁄₁₆d. per lb., leaving a margin of 2¹⁄₈d. These figures are based upon the assumption that American cotton of middling quality is used in each case. Thus the price of yarn is much less, while that of cotton is little reduced. It is true that a margin of 2¹⁄₈d. is barely sufficient to permit of a profit being made, but ¹⁄₈d. per lb. added will do 80, and a margin of 2¹⁄₂d. is considered a large one in these days.

(6) This reduction in the cost of production has not been brought about by any diminution in the wages of the operatives, as could very clearly be shown if it were necessary. Nor is it the result of a lessened cost of erection. A spinning mill of 40,000 spindles, which in 1835 would be looked upon as a large one, cost, at that time, from 24 to 26 shillings per spindle to erect, including the buildings and accessories. At the present time mills are built to contain as many as 110,000 spindles, and these are filled ready for work at a cost not exceeding 21 shillings per spindle, the apportionment of which is as follows: The machinery costs nine shillings, the buildings eight shillings, and the engines, boilers, furnishings, and all accessories four shillings per spindle. Considering the great increase in the productive power of the machinery, the fact that it is so much less expensive to work, and that each machine is of much greater capacity, the figures given show that the tendency towards diminished cost is owing very largely to the efforts of machine makers.

(7) It is not necessary to pursue this matter further, as the present work is not intended as a statistical abstract, but the few facts stated show that in the general march of improvement the textile mechanic has not been idle. A consideration of the methods of construction adopted to-day, as compared with those in vogue even so recently as twenty years ago, will further demonstrate this fact. Formerly the work of construction was very largely if not mainly carried out by fitters who were engaged in manually shaping the brackets and fitting them to the frames. The brackets were formed with feet, on which were cast nipples or projections. These were used to reduce the labour in filing, and, as the bracket was always fitted on to the face produced in the ordinary operation of casting, it will be seen that anything tending to diminish the work of fitting was valuable. But as the bedding of the brackets was dependent upon the proper shaping of a few points, the tendency to slip was considerable. Although, by being always engaged in fitting a few patterns of brackets, the workmen became extraordinarily expert, the method was at best an uncertain one, and did not lead to the rigidity absolutely essential in high-speed machines.

(8) All this is now changed, and the machine tool enables the work to be at once more expeditiously and economically carried out. The labours of mechanics of precision, like the late Sir Joseph Whitworth, are bearing fruit, and the effect is seen in the comparative excellence of the product. The solidity of English machinery has been sometimes scoffed at by Continental and American rivals, but it would be difficult to find any which runs at higher velocities with greater steadiness and less repairs. It cannot be too often insisted on that the rigidity which arises from mere weight is by no means an unimportant quality. Of course, there are limits to this as to every other principle, but generally it is a true one. Of quite as much importance is the rigidity which comes from sound construction; and in this respect modern spinning machinery is remarkable. Instead of a framing built up by hand with its various pieces manually fitted, it is now made in a much more enduring way. Raised faces are formed on the framing, which are planed or milled, so as to be quite true. To these the cross-beams or bars, the ends of which are similarly treated, are bolted. Thus, instead of the contact of several narrow faces, two broad plane surfaces are bolted together, and it will be easily seen how much more solid the framing will be in consequence. Again, in lieu of each part being at once like and unlike, as must necessarily happen when it is hand-fitted, it is now shaped by special machinery to templates, thus being interchangeable. The rails or beams to which bearings, brackets, or spindles are to be attached are planed or milled accurately on their surfaces, so that the long and unsatisfactory labour of fitting each piece separately is substituted by a true mechanical process. The advent of the milling machine and the discovery of the wonderful economic power of the circular cutter has had a wide-reaching influence. In brief, the present is an age of an increased development of machine instead of manual treatment, which has gone far to revolutionise the machinery used in spinning. Every student who may hereafter be engaged in the construction of this class of machinery should impress firmly upon his mind the fact that the machine tool is the best instrument for his purpose, and should develop it as far as possible. A special tool is invaluable, and the opportunities for its use are always increasing.

(9) A comparison of the speeds of various machines will demonstrate the value of improved construction. Mule spindles, which in 1834 were run at a maximum velocity of 4,500 revolutions per minute, are now revolved 11,000 times per minute with much greater ease and freedom from vibration. The throstle spindles running at a speed of 4,500 revolutions, are superseded by ring spindles, which rotate from 9,000 to 11,000 times per minute. As shown in Chapter [XII], it would be impossible to attain such a velocity unless the spindles were accurately constructed by special tools. Although the mechanism of a ring spindle is much more elaborate than that of a throstle spindle, the cost of the one but little exceeds that of the other. Again, a carding engine cylinder, formerly made of wood, and running 80 to 100 revolutions, is now constructed entirely of iron, and revolved at from 160 to 180 times per minute. In spite of this increase it is more free from vibration than its slower running predecessor. A similar comparison can be made of every machine with like results, but it is not necessary. Enough has been said to show the important part played by the machinist, to whom, as was pointed out in paragraph 1, most of the credit is due. The economical improvement which is noticeable in the condition of the workpeople is largely the result of the improvements made in the machinery. In fewer hours more work can be turned out, and this with a constantly decreasing strain upon the operatives. The breakage of the fibres in the various stages of manufacture is reduced to a very low point, with the twofold advantage of diminished waste and decreased labour.

(10) A modern mill differs from its immediate predecessor, not only in the quality of the machinery but in its general construction. The height and width of the whole building have materially increased, and the result is that the rooms in which the operations of spinning are conducted are both lighter and more airy. The building is usually made as far as possible fire-proof, and is of very substantial design and construction. The larger number of spindles in a mill necessarily imply greater capacity, but there is no comparison between the low-ceilinged, imperfectly lighted and ventilated rooms of the last generation with the airy and light erections of to-day. The sanitary arrangements are infinitely superior, and there is a noticeable improvement in the health and physique of the workpeople arising therefrom.

(11) Among the features which deserve mention is the improved type of engines used. In lieu of the old-fashioned beam engine, compounded or otherwise, working at a steam pressure of 50lb. or less, the modern engine is of the horizontal type. The favourite class for mill driving is the tandem compound, in which the high pressure cylinder is behind the low-pressure, but on the same bed. Latterly the vertical triple expansion engine has been adopted in a few cases, and there is a continual tendency towards higher steam pressures and more expansions. The introduction of steel boiler plates has rendered the construction of steam boilers for high pressures much more easy, and the author has seen a Lancashire boiler, intended for habitual use at a pressure of 220lb., tested with highly satisfactory results. Within limits, therefore, there is room for a further increase from the normal working pressure of 80lb. The steam-engines used are mostly of the Corliss type, with quick cut-off gear of high efficiency, and they are constructed to develop in many cases from 1,000 to 2,000 horsepower. The water used for condensing purposes is stored in reservoirs or “lodges,” from which it is drawn as required. It is sometimes difficult to cool it sufficiently to get a good vacuum, owing to the fact that the cooling and storage space is insufficient. For this purpose a type of condenser known as Theisen’s, which has been largely adopted in Germany and is now being introduced into this country, will be of value. It is arranged as a surface condenser, the steam passing through the tubes and being cooled by water surrounding them. In lieu of giving the water a circulatory movement it always remains in one position, any loss by evaporation being replaced. Between each vertical row of pipes cast-iron discs revolve, which are fixed on a shaft suitably driven. As each disc dips into the water—which is usually about 160 deg. F.—it picks up a thin film and carries it round in its revolution. At the upper part of the case, in which the discs revolve, an air propeller is fixed, which sends a current of air past and through the spaces between the discs. This leads to a rapid cooling of the disc and its water film, the heat absorbed by the water being in this way dissipated. The action is one of evaporative cooling, of which many instances abound, and is very effective. An equal weight of water will effectually condense any given volume of steam, and this quantity is not difficult to find in most places. The results obtained by the Union Engineering Company in this country have been satisfactory, and there appears to be no doubt as to the efficacy of the machine. Steadiness of rotation is a sine qua non in mill engines, a very slight difference in their velocity having a great effect upon the work of the mill. This is now attained in most cases with certainty, and by means of the Moscrop Recorder—an instrument denoting graphically the changes of speed—a very salutary check is kept upon the engineer. In order to prevent any variations occurring high-speed governors are largely employed, and in some cases their action is aided by special means, such as Knowles’s supplementary governor or Higginson’s patent regulator. Either of these appliances give good results, and the last named is very simple and effective.

(12) Up to within 15 or 20 years ago the most common mode of transmitting the power developed by the steam engine was by means of toothed gearing. About that period the American method of driving by a series of broad belts was introduced and for a time was largely adopted. When toothed gearing was used the power was conveyed to the various flats or storeys of the mill by means of an upright shaft, on which were bevel wheels gearing with others on the line shafts. The introduction of belt driving led to a system of transmitting the power to the main shaft in each room independently of its fellows, and this system found further development when driving by a series of ropes was adopted a short time afterwards. In this case the power is taken off by a number of ropes working in the grooves of a large pulley on the engine shaft and of smaller ones fixed on the line shafts. This is now the favourite method of driving and is more extensively adopted than any other. The reason for this is principally the ease with which breakdowns can be guarded against. If a rope breaks it falls into the race, and in rare instances does it become entangled. It is only necessary to replace it, and any delay thus caused is not great.

(13) As the question of driving is a somewhat important one a few remarks may be made on it. There is no doubt that toothed gearing properly constructed forms the most economical method, the loss of power in transmission not exceeding 2¹⁄₂ per cent. In constructing wheels for this purpose care should be taken that the tooth is not too long, ⁵⁄₈ths of the pitch being a sufficient length. Next to toothed wheels for economy belts may be placed. The loss in transmission varies, if the belts are properly applied, from three to five per cent. A good speed for leather belts is 3,000 feet per minute if they are single, and 4,000 feet if double. Rope driving is the least economical of the three methods, this arising from a variety of causes. Chief among these is the difficulty of maintaining an equal diameter in every rope of the series, which leads to a difference in their driving power, owing to their unequal engagement with the V grooves. Another cause of this loss of power is found in the fact that they jam in the grooves and have to be forcibly extracted as the pulleys revolve. The following rules laid down by Mr. Alexander Rea in a discussion, at a meeting of the Manchester Association of Engineers, on the subject of the comparative merits of the three systems of driving, are worth reproducing.

“The ropes should not be too large in diameter; it is much safer to use 25 1³⁄₄ inch ropes than 20 2 inch diameter ropes. The tension in the several ropes should be kept as low as possible. The power should be subdivided to different points. The centres of the several shafts should be kept well apart. The pulleys should be large in diameter. The best speed for the ropes is from 4,000 to 6,000 feet per minute. Care should be taken in turning the V groove pulleys; the best angle for these is now found to be 45 degrees.”

(14) As this subject of rope driving is an interesting one, it is worth noting that Mr. George Goodfellow, of Hyde, who has had a wide experience in this matter, confirms the advice as to small diameter of ropes. In the same discussion he stated that he did not now use larger diameters than 1³⁄₄ inch, and had ropes running successfully, the diameter of which was only 1¹⁄₄ inches. Mr. James Hartley also bore out this experience. By the reduction of ropes from 2 inches to 1¹⁄₄ inches diameter the friction diagram from the engine had been materially reduced, indicating a saving of power. Mr. J. H. Ratcliffe, of Dukinfield, has recently revived a method by which, instead of using a series of ropes, he uses one only, this being endless, and being wrapped spirally on the pulleys. At one point the slack is taken up by a compensating apparatus, so that the whole of the coils are tight back and front instead of having one side slack and bellying. For this arrangement Mr. Ratcliffe claims that it materially reduces the friction diagram, inasmuch as there is no necessity to drag the rope forcibly out of the grooves at each revolution. It is not necessary for a detailed examination of this subject to be made, but the hints given will probably prove useful to many readers.

(15) It is essential, owing to the peculiar structure of the cotton fibre, to which reference will be made in the next chapter, that the rooms in which spinning is conducted should be heated to a certain temperature. Closely allied to this question is that of humidification. It is not only essential to have heat, but that must be accompanied by a certain amount of moisture, a point which is often neglected. Spinning rooms are often heated to over 90° F., which is quite unnecessary, and is, moreover, detrimental to good work. At such a temperature much of the natural moisture of the cotton is extracted, and the fibre becomes harsh and brittle. A temperature of from 75° to 80° F., with a humidity of about 75 percent, is absolutely the best condition for spinning. The question is an important one, and deserves greater consideration at the hands of spinners. The artificial heat required is now obtained by the use of wrought-iron steam pipes, through which high-pressure steam is passed. The radiation from these is much greater than from cast-iron pipes of larger diameter filled with low-pressure steam.

(16) Having thus briefly glanced at some of the chief features of modern practice, it is now only necessary to say that the utmost cleanliness is absolutely essential to good working. The manipulation of the cotton is now so largely automatically performed that there is much less difficulty in keeping a mill clean than formerly. It should be the aim of every spinner to diminish the handling of the material as much as possible, and students of this subject should remember that it is never too early to begin to deal with the cotton so as to prepare it for subsequent treatment. Efficient purification at an early stage is a great help towards economical and efficient spinning. In conclusion, it may be remarked that one of the worst faults in studying a subject of this sort is any kind of crystallised thought. The conditions of work vary from day to day, and there are wise variations in procedure which can easily be discovered by the observant mind. This watchful attitude is the proper one to cultivate, and the succeeding pages are written in the hope that they will lead some reader to a deeper and closer observation of the facts which are discoverable in the actual work of construction or spinning.

CHAPTER II.
THE STRUCTURE OF COTTON.

(17) The cotton plant is indigenous to many tropical countries, in which it is often found in a wild state. The product of the wild plant is, however, quite unsuitable for manufacturing purposes, and, even in cases where cotton is produced by cultivation, the value of the fibre varies very largely. Into the question of the growth and structure of the fibre it is not necessary to go in detail, as this is a subject which has a literature of its own. The student who is desirous of obtaining a thorough knowledge of the subject can find it fully treated in the “Structure of the Cotton Fibre,” by Dr. Bowman, and in a recent work by Mr. Hugh Monie, jun., of Glasgow. It will suffice for present purposes to state briefly the characteristics of cotton, which are of essential importance in its subsequent treatment mechanically. The cotton fibre is a hollow tube of cellular construction, and is of an oval or flattened cylindrical shape. Ripe or fully matured fibres of the best cotton are convoluted or spirally twisted on their axis, and the edge of such a fibre presents a corrugated appearance. The regularity of the convolutions, or twists, is greatest in the highest class of cotton, and reaches its lowest point in the poorer grades. One important effect of such a formation is that each fibre naturally tends to coil round its neighbour, and thus lends itself to spinning. The outer sheath of each fibre is apparently continuous, and the diameter is greater at the end which is attached to the seed. The diameter of the fibre varies from ¹⁄₁₅₆₂ of an inch in the case of Sea Island cotton, to ¹⁄₁₁₈₅ of an inch in Indian cotton. In length a similar variation is observable, reaching a mean of 1·8 inch in Sea Island, and being as low as 0·8 inch in Indian cotton. The length of the fibres in any particular class of cotton is known as the “staple,” and this is one of the chief commercial merits of the better kinds. The strength of cotton fibres varies very materially, and on the authority of Mr. Charles O’Neill, of Manchester, the order in which the various classes ought to be placed is as follows:—Surat (Comptah), New Orleans, Queensland, Surat (Dhollerah), Pernambuco, Egyptian, Maranham, Upland, Sea Island. It does not necessarily follow that the possession of greater strength by one class of fibre over another involves an advantage, for the greatest strength is possessed by a fibre which is the most deficient in regularity of the convolute form and length, which are much more important than strength. Again, the diameter of Comptah cotton is much greater than that of longer stapled varieties, and this is important in determining the value to be placed upon the strength. Viewed in this light, Egyptian cotton is the strongest, and this fact, in conjunction with certain other qualities to which attention will afterwards be called, renders it of high value. It only remains to be said that a waxy covering is found on the outside of each fibre, which requires to be softened by heat during spinning so that the flexibility of the fibre may be fully maintained. Where it is intended to dye fabrics it is necessary to remove the whole or the greater part of this wax, and so permit the dye to penetrate the fibre. Having briefly indicated the chief characteristics of the cotton fibre, a detailed account of some of the principal varieties may now be given.

(18) Sea Island Cotton. This is the finest class of cotton produced, being long in the staple, very flexible, and having very regular convolutions. If care be taken in ginning, so that the fibre is not broken, the finest yarns can be produced from this variety. The length of Sea Island Cotton is stated by Dr. Bowman to reach 2·20 inches in the case of Florida grown, but Mr. Monie states the average length to be 1·8 inches. Mr. Evan Leigh confirms the higher length, but only in the case of cotton grown on the Edisto Island. Varieties of this grade are grown in Peru, Fiji, and Australia, the average lengths being respectively 1·56, 1·87, 1·65 inches. Fijian Sea Island is spoiled by bad ginning, which breaks the fibres very much. The colour of Sea Island cotton is a light creamy one, and is peculiar to it.

(19) Egyptian Cotton. Egyptian cotton varies considerably in colour, length, and quality. The variety known as Gallini is of a golden colour, the fibres being tough and strong, and the convolutions very regular. It has a mean length of 1·5 inch. Brown Egyptian is, as its name implies, of that colour, and like Gallini, the fibres are strong and tough, but are coarser, the convolutions are less regular, and the wall of the fibre is also denser. The mean length is 1·4 inch and the diameter ¹⁄₁₃₂₅ inch. White Egyptian is, perhaps, the most valuable of all this class of cotton when properly treated. It is of a light gold colour, the fibres being strong and pliable, but only partially spiral. As a result of this, the yarn spun is greater in diameter than that spun from Gallini (weights being equal), the fibres not lying so closely together. This cotton mixes well with American and Brazilian.

(20) Brazilian and Peruvian Cotton. Pernambuco cotton is of a slightly golden colour, and is, comparatively speaking, hard and wiry, being thus well adapted for twist yarn. The twists in the fibre are well developed, and the average length is 1·25 inch. Maranham is of a dull gold colour, mixing well with American cotton. There are several other varieties of Brazilian cotton, which need not be further referred to. Rough Peruvian cotton is very clean, of a creamy colour, and is possessed of an average strength. The fibres are only irregularly twisted, and an average length is 1·3 inch. The smooth variety is fairly regularly convoluted, and mixes well with Orleans.

(21) American. There are several varieties of American cotton, which are grown in the Southern States. Taking them in their order as regards length of staple, the first to notice is Orleans. The better classes of this are very uniform in length, clean and light in colour, often being pure white. One feature of Orleans cotton which renders it very acceptable to spinners, is that it is very flexible, and possessed of a high elasticity. In addition to this, as has been previously noted, its strength is fairly great, and generally its spiral form is well developed. The average length is about 1 inch. Texas cotton is less pliable than Orleans, darker in colour, and is not put on the market so free from immature fibre. Its diameter is greater, and its average length about equal to Orleans. Upland cotton is clean, and little waste is produced from it. The fibres are well suited for weft yarns, being soft and elastic, and of a very light colour. Spun without any admixture of other cotton, yarns as high as 425’s can be produced, but when mixed with Egyptian or some other strong fibre, higher counts can be obtained. Mobile is similar in colour to Orleans, and is equal to Uplands in strength. It is not so good as either of these for manufacturing purposes, being much dirtier, and having more flattened fibres in it.

(22) Indian. The whole of the cottons grown in India are less valuable than the preceding varieties, owing to the facts that they are not so regularly spiral, and that the staple is more variable. The highest class is Hingunghat, which is more convolute than any other Indian grown cotton. The fibres vary in diameter, but have an average length of 1·03 inch. Broach is brownish gold in colour and is fairly clean, although it is not thoroughly cleaned, and contains a good deal of leaf and nep. It is about 0·9 inch long, and is more regular in this respect than Hingunghat. The spirals are fewer in number, and it is stated by Mr. Monie that the walls are very liable to rupture. Dhollerah is of a white colour, and is best adapted for weft yarn. Oomrawuttee is creamy in colour, being strong but rather short in the staple. A good deal of impurity is found in this quality, but the convolute form is moderately developed. Tinnivelly is grown in the Madras Presidency, and is a fairly good cotton. In strength it is high and is very elastic, its colour being a dull, creamy one. The fibres have a small bore and thick walls, and are, in addition, only slightly twisted. The worst Indian fibre is Bengal, which is short, strong, and dirty.

(23) Commercial qualities. The recapitulation of the principal features of various growths of cotton just given enables their relative value for spinning to be pointed out, and at the same time to indicate the qualities it is desirable to retain during the subsequent mechanical treatment. Sea Island cotton is beyond doubt the finest quality existing, and, in the manufacture of fine counts, is absolutely essential. Its general excellence is undoubtedly attributable to the conditions under which it is grown, and even this might be improved by more careful cultivation. Egyptian cotton is also of great value in the production of good yarns, and is very largely used for this purpose. Owing to the existence of a number of short fibres, always found in commercial quantities, but present here in larger proportion, it is necessary to comb all Egyptian cotton. The chief advantage of its use is that being relatively stronger, smoother surfaced, and more flexible than qualities other than Sea Island, a large range of yarns for various uses can be spun at a price which enables them to be profitably used. The fibres are very regular in diameter, and when twisted lie very close together. The most widely used cotton is, however, the various brands of American, which have the advantage of careful attention during their growth and collection. In consequence of this, there is a very high uniformity attained, together with great freedom from all sorts of impurities, these two qualities rendering American cotton highly suited for general use. Indian cotton is coarser, harsher, and not so clean as other varieties, and requires greater care in its manufacture. Summing up, the desirable points in cotton are the length and regular convolute form of the fibre, together with its freedom from mechanical and chemical impurities. The object of the earlier mechanical processes through which cotton passes is to remove all the impurities, lay the fibres regularly and in equal numbers alongside each other, without breaking or rupturing them, and without destroying their natural tendency to twist round each other. In doing this, not merely do the seeds, leaf, and sand require removal, but also the short immature fibres which form into little knots or tangles called “neps.” Great care is needed in the preparatory stages so as to avoid damage, and it is especially necessary to avoid the removal of the waxy sheath which plays an important part in the manufacture of the fibre. The necessity for a warm, humid atmosphere has already been referred to, but it may be noted that it is very important on account of its softening effect upon the waxy sheath. If the latter be removed the heat becomes a source of difficulty instead of a help, as the natural moisture existing in the fibre is more speedily absorbed.

CHAPTER III.
GINNING AND MIXING MACHINES.

(24) When the cotton is ready for harvesting it is picked from the shrubs by hand. There have been many attempts to pick it by machinery, but these have not hitherto been very successful. After picking, it is subjected to the action of a machine called a “gin,” which is sometimes arranged to be worked by hand, but more often by power. In the latter case the machines are placed in a shed, and the cotton is brought there for treatment. The object of ginning is to remove from the cotton the seeds, which adhere closely to the fibre, and which have of late years acquired considerable value for oil-producing purposes. In order to remove them it is necessary that the fibre should be held in some way while it is submitted to a rubbing or scraping action, by which the seed is separated. To effectually perform this function great care is required, as otherwise a quantity of the seed is broken, and the fibres are rubbed up into “neps.” If either of these effects is produced additional labour is thrown on the spinner in his subsequent treatment, and it is therefore desirable to avoid such a manipulation of the machine as would lead to so undesirable a result.

(25) In Figs. [1] and [2] a single Macarthy gin is illustrated in part sectional side elevation and front elevation. This is a type which, in principle, is now largely adopted. It consists of a roller A, rotated in the direction shown by the arrow, by means of a strap passing over a pulley fixed on the end of the roller shaft. The latter is square, and is passed through the centre of the roller, fitting a corresponding hole in the latter, and being carried by suitable bearings fixed on the machine frame. In constructing the roller A the following method is adopted. Wood segments are fitted together so as to form the complete cylinder, or the latter may be made in one piece. Having produced the body, it is fixed on the shaft, and is then turned quite round and parallel. Upon the surface so prepared a thick covering of walrus leather B is fixed, in which spiral grooves are formed. The rough surface of the leather, as the roller is revolving, seizes the cotton fibres as they are fed along the table F, which has a grid G at its inner end, a special feed being sometimes fitted. When the fibres are drawn in by the roller they are taken under a knife blade C, which is fixed above the roller by means of the sets of clamps D and E. The clamps D bind the blade to its bearings, and those marked E are used to regulate its pressure on the roller A. As the roller occasionally becomes hollow the wisdom of this procedure will be seen. A crank shaft is placed and driven from the shaft of the roller, and gives a rapid reciprocating motion to a connecting rod I, which has at its upper end a blade H. The height of the blade H is regulated by means of the adjustment of the connecting rod strap, to which it is jointed, and which can be packed to any desired amount. The blade is coupled to radius arms J, adjustable by nuts at their outer ends, and oscillating on a rod fixed below the feed-table.

(26) As the fibres are drawn under the upper blade C, the lower blade H pushes up the seeds, which cannot pass between the roller and the blade C. In this way the seeds are freed from the fibre, which is carried forward and thrown off at the front of the machine, or it may be stripped by a fixed blade. The setting of the blades C and H should be arranged so that the necessary pressure is applied to the seeds to free them, but care must be taken that the lower blade does not rise so high as to crush them. It should also be set relatively to the roller, so as not to roll up the fibre by having close contact with either the roller or upper blade, while effectually removing the seeds. Other forms of ginning machines are made, including one in which rollers formed of a number of saws are employed, but their use is not so large as that of the Macarthy machine, which may be taken as typical.

(27) After the cotton is ginned, it is pressed in large hydraulic presses into bales of various sizes and weights, ranging from 400 to 600lbs. each. In this form it is imported into this country, and delivered to the mill-owners. The purchases of the material are made from samples of a few pounds taken from one or two bales of a lot of the same brand, and it is essential in purchasing that not only the “staple” but the condition in which the cotton is packed should be taken into account. In some seasons the percentage of moisture is much higher than in others, and in wet seasons a large weight of adherent sand is certain to be found. This, indeed, is the case always, but it is much greater after a bad season than when the weather is normal during picking. The question of the delivered condition of the fibre is a very sore one commercially, as it results in serious loss to the millowner, and there is little doubt that in many cases a fraudulent intermixture of sand is made.

Figs. 1, 2.J.N.

Fig. 3.J.N.

Fig. 4.J.N.

(28) Whatever may be the condition in which the cotton is received, the first operation at the mill is to open out the bale and break it up into pieces of a convenient size. For many years this was conducted purely as a manual operation, but an arrangement which was made by Messrs. Platt Bros. and Co., in 1855, and has been working ever since, is shown in Fig. [3]. This consists of a lattice feed table F, which delivers the cotton and brings it into the range of action of an opener cylinder C. The latter opened the material to a considerable extent, and threw it on to a second lattice H, by which it was delivered to a third one, and conveyed to the mixing stacks in a manner to be afterwards described. The operation is now almost always carried out by a machine known as a “bale breaker,” a perspective view of which, as made by Messrs. Platt Bros. and Co. Limited, is shown in Fig. [4]. It consists of a feed table, placed between the projecting framework, and is usually of the lattice type. The lattice feed apron consists of a number of narrow strips of wood fixed to two endless bands passing round rollers at each end of a longitudinal frame fixed to the machine. By suitably driving one or both of the rollers a continuous motion is obtained, and the wood strips being each free from the other no difficulty is experienced in forming an endless apron or feed table. The cotton is placed upon the table in large pieces or lumps, just as these are taken from the bale, and they are carried forward until they come into contact with the first pair of rollers. There are usually four pairs of rollers driven by means of the spur pinions shown in the illustrations. The first pair are provided with coarsely-pitched blunt teeth or spikes, which seize the cotton and pass it onward to the next pair, which are of similar construction. The last pair of rollers are usually made with coarse, longitudinal corrugations, or flutes, as shown in Fig. [4], which deliver the cotton either on to the floor of the room, or on to lattice aprons arranged as hereafter noted. The top rollers are weighted by helical springs in the manner shown, and can easily yield if any obstruction or unusually large piece of material passes between them. The speed of the rollers increases rapidly, but there is a divergence of opinion as to the proportion of increase over the whole series. It will be well, therefore, at this point to state the conditions of the case fully.

(29) Before doing so, however, it is necessary to explain a term which even at this early stage is used, and which is a common one throughout the whole series of operations constituting spinning. The variation in the speed of the rollers of the bale breaker is known as its “draught.” In other words, an elongation or enlargement of the bulk of the cotton occurs in exact proportion to the velocity of the rollers. Thus, if the relative speed of the first and last of the series of rollers is as 1: 30, the draught of the machine is the same. In the case of the bale breaker the draught results merely in an increase in the bulk of the cotton, but subsequently it leads to an elongation of the sheet or sliver into which it is formed.

(30) It being highly desirable that the naturally open fleecy condition of the cotton shall be restored at the earliest moment, the question arises, What shall be the draught of the bale breaker rollers? Is it necessary to do more than break up the lumps of cotton into smaller pieces, which can be readily treated by the subsequent machines? To these questions different answers are given. On the one hand, it is contended that what is required is to reproduce the conditions of hand breaking, by which the cotton was pulled from the bales in small tufts ready for delivery to the opening machinery. Another practice advocated is to so pull the lumps into which the bale is broken up that the cotton when delivered is in an open fleecy condition. It would be preferred by spinners if they could obtain the cotton in the loosely packed condition in which it is received by the Indian spinners, for instance. As this cannot be done, owing to commercial and transit considerations, the question arises whether the first stage in the processes conducted in this country is not the right one to restore this condition.

(31) Between the two positions formulated there is a wide divergence, but, to the author, the latter appears to possess the balance of advantage. There can be no doubt that the preparation of the fibre cannot be commenced at too early a stage, and, as efficient cleansing is one of the first objects to be attained, it follows that the earlier the open condition of the cotton is reached the more readily can cleaning be effected. It must not be forgotten that care is necessary to avoid possible damage to the fibres, but, with rollers properly speeded, there appears to be no reason to expect such a result.

(32) In consequence of the divergent views held, the draught of a bale breaker varies considerably. In some cases it is only 2: 1, while in others it reaches 30: 1. The former is the rule adopted by Messrs. Crighton and Sons, who advocate the first course named, and the latter that adopted by Messrs. Lord Brothers, who prefer the second. Messrs. Platt Brothers and Company recommend a wise variation in this respect, proceeding upon the principle that different staples require different treatment. Thus one machine made by them has four rollers with a large draught, this being used for good staples, and producing as much as 90,000lbs. weight in 50 hours. In dealing with Surat cotton, which is more hardly pressed, two sets of rollers are used, followed by a beating cylinder by which the cotton is thoroughly broken up (Fig. [8]). In each case it is customary to attach lattices to the machine, by which the cotton is carried forward and deposited in the mixing bins (E Fig. [13]). (See also Figs. [6], [7], and [8]). Another method is to treat Surat cotton by first passing it through breaker rollers, and thence through a Crighton cylinder, described in Chapter [IV]. The bale breaker may in this case be used either singly or as part of the combination.

(33) The rollers are made in two ways. They are cast in one piece and are mounted upon the shaft; or are built up from a number of discs threaded and fastened upon the shaft and bolted together. The latter is the preferable course, the breakage of a few teeth being easily remedied.

Fig. 5.J.N.

(34) Before proceeding further, reference may be made to Fig. [5], which is a transverse section of the machine as made by Messrs. Dobson and Barlow. The top rollers of the machine, as ordinarily made, are provided with spring weighting, in order to permit them to rise if an unusually large piece of cotton is passed between them. If this enters at one side of the machine it will be at once seen that the roller will be raised at that side, and that its axis will be angularly disposed to that of the bottom roller. The two rollers will only be near each other at one side, and between them, across the whole of the width of the machine, will be a gradually increasing space through which lumps of cotton can pass unpulled. This is a defect of more or less magnitude, but is one which is ingeniously remedied in the machine shown in Fig. [5]. Only one line of rollers, marked U V Y Z, is used, by two of which the pulling is effected. Below these the noses of iron bars or levers, Q R, fulcrumed on knife edges, are placed. The bars are a few inches wide, and extend below the rollers over their entire width. The cotton passes over these “pedal” levers, which are weighted at their other end, and yield, as shown by the dotted lines, when an extra large piece of cotton passes. The weight is sufficient to enable the cotton to be held until it is pulled by the roller. It will be at once seen that only the pedals affected by the lump will be depressed, the remainder occupying their normal relative position to the roller, which is fixed by the stop shown. In this way the presence of a thick piece at one point in the width of the rollers does not affect the pulling at another point.

Fig. 6.J.N.

Fig. 7.J.N.

(35) The cotton being palled, it is necessary to mix it. This is effected by delivering it upon a second lattice, B Fig. [13], which can be made of any desired length, and by which the cotton can be delivered on to a third lattice C running transversely or in any other direction. Three such arrangements—the sketches supplied by Messrs. Platt Bros. and Company—are shown in Figs. [6], [7], and [8], but there is practically no limit to them. By means of these devices as much as 90,000lbs. weight can be laid down per week by two workmen. To avoid the risk of fire, the flutes are so arranged as not to come into contact, but it is advisable to place the machine in a building removed, if possible, from the main structure.

(36) Having broken up the bale as described, the cotton is in a condition to be mixed. This operation is one of the most important in the economy of a cotton mill, and on its judicious and thorough accomplishment depends very often the production of a profit or loss. In order to obtain the best possible yarn the longest-stapled cotton should be used, and should be selected so that the fibres, when spun, are as nearly as possible of one length. By careful selection a practically perfect yarn can be produced, but it would naturally be a dear one. It is, however, possible to apply the same principle in the production of cheaper qualities of yarn. Briefly stated, the principle is, that to spin a good yarn it is necessary to use cotton in which the fibres are of approximately the same length. The longer the “staple” of the cotton the better the yarn; but, even when short staples are used, this selection is still essential to success. This does not necessarily mean that the same grade of cotton should be used exclusively, but, on the contrary, several can be mixed, provided that the staples are equal, even if they are not of the same commercial value, and differ in other characteristics. By a careful selection of cotton a mixture can be obtained from which a good even yarn of fair strength can be spun, the cost of which would be lower than it would be if a single good grade only was used.

Fig. 8.J.N.

(37) It is the practice in making a mixing to place round the breaker bales of the various grades which are to compose it. The attendant takes a layer from each bale in succession, and places it on the feed lattice of the bale breaker, by which it is broken and partially mixed, so that when stacked the elements of the mixing are well incorporated. The size of the stack depends very largely on the requirements of the spinner, but as most mills now are employed on a small range of counts, some of them on one or two, it is most usual to make a large one containing sufficient cotton to last for several weeks. By pursuing this course there is a very much better chance of getting a regular quality of yarn, which is essential to the commercial success of the mill. In taking cotton from the heap it is the best plan to begin at the top of the face and work downwards in a straight line, as by this procedure a uniform quantity of the different elements in the mixing is obtained. It is desirable to make a small stack of the same classes of cotton as the larger one is to be composed of, and in the same proportion. By passing this through the various machines a test can be made of its yarn producing qualities, and the mixture of the larger stack can be varied so as to remedy any defects discovered in the smaller one. It is impossible to lay down any definite rule as to mixings, the production of which is a matter of experience, and can only be arrived successfully at in that way. Not only must the strength and cost of the yarn be considered, but also its colour, and it is for this reason essential that a thorough knowledge of the structure and characteristics of various growths should be acquired in addition to one of commercial values.

(38) It will be easily seen, when the operations of the various machines employed in cotton spinning are considered, how essential it is that the fibres in a mixing should be approximately equal in length. Unless this condition is observed there is likely to be a good deal of loss from fly in the carding engine, and the slivers in the drawing frame would tend to have the long fibres in the centre and the short ones on the surface, owing to the difficulty experienced in drawing different lengths with the same setting of rollers. These remarks are, of course, only relatively true, as it is possible to mix different staples economically, but the process is a difficult one. For instance, in the scutching room, laps, each consisting of cotton of different staples, can be fed simultaneously on the same lattice, and so produce a lap of the mixed staples. It is found to give the best results when the laps are made on the opener and mixed on the intermediate scutcher in the proportion required. By these means a better mixing is obtained than if the laps are put on the finishing scutchor only. Individual experience is the guide to a thorough comprehension of this department of spinning, and beyond enunciating these general principles no aid can be given to the student which is likely to be of value. The actual condition of even the same class of cotton, in different seasons, varies so largely that a mixture which is valuable one season is unsuitable in the next.

CHAPTER IV.
THE OPENING MACHINE.

(39) Mixing being completed, the cotton is treated by machines specially designed to remove the impurities which are always mixed with it as received from the shipper. These impurities include sand, dirt, broken seed, and leaf. In addition to these there is a certain quantity of “nep” which is caused, as previously described, by the matting together of short, unripe, or immature fibres. To eliminate the whole of these substances, two sets of machines are required; the first being responsible for the removal of the heavier foreign bodies, such as sand and dirt, and the second for that of leaf, nep, and short fibres.

(40) Of the machines in the first division the opening machine, or more briefly the “opener,” is the first. Its raison d’être is found in the matted condition of the cotton as taken from the bale, and the less open it is when taken from the stack, the greater the work of the machine. As the name indicates, the object of the latter is to disentangle the fibres, but it is also designed to remove many of the impurities held by the cotton. This twofold aim is the one with which all the series of cleaning machines are constructed.

(41) The method invariably pursued in opening is to beat the cotton by subjecting it to the blows of arms revolving with considerable velocity. It may aid in the understanding of the process, if a few words are said as to the primitive method of cleaning. Formerly the material was laid upon grids in small quantities, and was submitted to repeated light blows of rods or sticks delivered manually. In this way the mass was gradually beaten into a fleecy condition, and the dirt held by it dropped through the interstices of the grid. In some respects, this treatment has never been equalled, but it is, of necessity, very slow, and could not be commercially employed at the present day. At the same time, it affords a clear indication of the needs of the case, and is a guide to the proper treatment.

(42) In dealing with the fibre by revolving beaters of any kind, two things are essential to success. First, the blow given must be of such a character that the fibres are completely separated, while any rupture or breakage of them is avoided. Second, the surface against which the cotton is flung after being struck by the beater, must be arranged to permit of the free passage of all impurities, while, at the same time, so arresting the movement of the tufts or pieces of cotton as to shake out the extraneous substances.

(43) The direction in which the cotton enters the machine, the diameter, construction, and shape of the beater arm, and the speed of the beater, are three of the essential features of a machine of this kind. The successful removal of the impurities depends on the rate of the feed—that is, the amount of material passed into the machine in a given time—the shape of the projections on the casing surrounding the beater, and the distance of these from each other; in other words, their pitch. It is not a difficult matter to effectually cleanse the cotton, so long as regard is not paid to the loss arising from damaged or broken fibres, or from the amount of fibre driven out with the dirt. It is, however, always to be remembered that it is desirable in any process to utilise every portion of the material which is capable of being worked up, and herein lies the chief difficulty of the subject. In brief, the essential consideration is a commercial one, and that machine is the best, and is used most skilfully, which effectually opens the matted cotton and shakes out the largest body of impurities with the least loss of fibre, either from its being driven out with the dirt or by breakage or rupture. Economy and efficiency are the watchwords of a good spinner, and nowhere is this combination more desirable than in the early stages of the manufacture.

(44) There are three principal forms of machine used for the purpose of opening—the Oldham Willow, the Porcupine, and the Crighton Opener. The former is now employed rarely for cotton, but extensively for the manufacture of yarn from waste. The other two are often employed, but the Crighton type of machine is perhaps more widely used than any other. There is another type of machine, which is also in extensive employment, to which reference should be made, viz., a modified opener, on the Willow model, of which a description will be given.

(45) The Willow is constructed with a revolving cylinder, about forty inches wide and the same diameter, fixed on a shaft borne by suitable pedestals. It is provided with several rows of blunt teeth on its periphery. Above the cylinder a semi-circular casing is fixed, which is provided with similar projections to those of the cylinder. Below the latter a grating, grid, or “undercasing,” formed of a number of parallel bars, is placed. The cotton is flung against these bars, and the loosened dirt falls through the spaces between them, being drawn away by an exhaust fan and delivered outside the room. It is the usual practice to feed the machine by an endless lattice, or apron, of a similar construction to that previously described. When the cotton enters the machine it is struck by the teeth on the cylinder and thrown forcibly against the projections on the casing. The blow thus given, combined with the periodical arrest of its motion, causes the cotton to be thoroughly opened and shaken, the dirt falling downwards and being drawn away by the air current. As has been said, the Willow is falling into disfavour. The cotton is subjected to too severe punishment, and is therefore damaged. In addition to this, it is sometimes carried round several times, and is formed into a sort of rope, which renders its subsequent treatment more difficult. Moreover, the waste is greater than is desirable, and, generally speaking, the use of this machine for cotton is of doubtful utility.

(46) In Fig. [9] a longitudinal section of an opener, which in some respects is a modified type of Willow, is illustrated. This machine is made by Messrs. Taylor, Lang and Co., Limited. It consists of a feed lattice Q, which travels in the direction of the arrow, and delivers the cotton to the pair of feed rollers shown. These are duplicated when no regulating apparatus is used, and are three inches in diameter. The cotton is delivered at any desired speed by the rollers, and as it projects from them is struck by the spikes or teeth on the cylinder O, which revolves in the direction shown by the arrow. Surrounding the cylinder is a case P, the inner surface of which has a number of projecting nogs formed on it, against which the cotton is flung with considerable force. This shakes out the dirt to a great extent, and opens the material. After passing the casing P the cotton is taken over a circular grid surrounding one side of the cylinder, and contained in the body of the machine. This grid is formed of a number of steel bars, between each pair of which an opening is left. Thus as the disentangled cotton passes over it the heavy dirt falls out through the openings into a space left for the purpose. After passing the grid the material leaves the cylinder by the passage shown, immediately on entering which it travels over the top of fixed grids R, through which the sand and similar material can fall. After this the cotton is either delivered into the room or is carried forward to a pair of “cages” S, through which a current of air is drawn. This part of the machine will be described in the next chapter, and it is only necessary to say that the fleece of cotton is formed into a sheet and rolled up as shown at L, into a “lap.” If the cotton is delivered loose it is thrown on to a second lattice, by which the delivery is made. In order to secure a regulation of the air current the louvre openings I are provided. The area of the cleansing surface in this machine is great, and 50,000lbs. of cotton can be cleaned in a week of 60 hours unless a “lap” is formed, when the quantitity is reduced to 28,000lbs.

Fig. 9.J.N.

Fig. 10.J.N.

(47) In Fig. [10] is illustrated, also in longitudinal elevation, a machine made by Messrs. Dobson and Barlow. The cotton is fed by a lattice L, as in the preceding example, the course of which is clearly shown. In this case the machine is fitted with pedal levers V, these being employed to regulate the feed. This motion and its method of action will be described at length in the next chapter. It suffices to say that the cotton on issuing from the feed roller is struck by teeth or projections on the surface of the cylinder O which revolves from left to right. Surrounding the latter is a semi-circular grid K with conical teeth, which encircles the cylinder for more than half its circumference, through which the dirt is thrown, the cotton being cleaned by these means. It will be noticed that in this machine the area of the circular grid K is large, and that the material at once passes upon it after it is struck by the cylinder. As soon as the cotton leaves the surface of K it is carried forward over the grid U, placed in a position well calculated to allow of the easy movement of the material, and by means of which the removal of the dirt and sand is more easily effected. The grid U is also made of considerable area, so as to afford a large cleaning surface, which is a desideratum in this class of machine. After leaving U the cotton is collected on the cages D, and subsequently passed through the scutching machine, which in this case is combined with the opener. As this machine is used as a separate one, it will be better to leave its description until it is dealt with by itself. It is only necessary to say that it will be shown by numerous examples that the whole of the cleaning machines are often combined in various ways, which are arranged to suit the special circumstances of any case. These are so different that the combinations are widely diverse.

Fig. [11].J.N.

Fig. 12.J.N.

(48) The Porcupine opener is so named from the employment of a cylinder or beater consisting of a number of teeth spikes or blades. Two forms of the beater, as made by Messrs. Lord Brothers, are shown respectively in Figs. [11] and [12]. The form shown in Fig. [11] is intended for use in cleaning long-stapled cotton, and consists of a number of discs secured to a central shaft. To these steel blades are bolted, which are so shaped that they can be reversed when worn. The beater illustrated in Fig. [12] is formed of a number of cast-iron discs, each of which is hollowed on one side, and has a projecting flange or boss on the other. These are turned to fit one another, and are bolted together by long screws. They are further bound by a nut fitting on a screwed part at one end of the shaft, by which they are pressed against a collar at the other end. The teeth are V shaped and are chilled, being readily sharpened after wear. In the event of the teeth of one of the discs being broken, it is only necessary to remove it by breaking it up. An additional disc can then be put on the end of the shaft, and the whole screwed up again as at first. In this way the whole of the advantages of a solid roller are secured, with much greater facilities for repair.

Fig. 13.J.N.

(49) However the cylinder is constructed it is sustained by bearings secured to the framing of the machine. Beneath it a grating or grid is fixed, similar in construction to those previously described. The bars are in all cases shaped so as to present a sharp angle to the cotton as it is thrown forward by the cylinder. A dirt chamber is, as usual, formed below the grid. The cotton is fed by a lattice and feed rollers. The latter are formed in the ordinary way, with a number of circumferential V grooves, crossed by a series of similar longitudinal grooves, so as to form a large number of teeth, which securely hold the material as it is fed. As the cylinder revolves 1,000 times per minute, the teeth strike the cotton and disentangle the fibres, throwing them with considerable force against the grid.

(50) Although the Porcupine opener can be used separately and the cotton discharged into the room, it is more usually employed in connection with some other type of opener, or with a scutching machine. Formerly it was a common practice to use this machine separately, in which case it was fitted with two cylinders one behind the other. Now it is mostly employed as a feeder to another machine, and the combination gives very effective cleaning.

(51) Such an arrangement is shown in Fig. [13], which is a special one of Messrs. Platt Bros. and Co. The lattice feed F is placed alongside the mixing bins, and is provided with a large collecting roller, behind which are a series of pedals, described in the next chapter, and two pairs of breaker cylinders. By these the cotton is fed regularly and broken up into small pieces, or partially opened before being passed forward to the opener cylinder. The Porcupine feed rollers G deliver the cotton, in the case illustrated, into the air tubes D, and thence over a patent dust trunk K, where much of the dirt is deposited, and which is afterwards described.

Fig. 14.

(52) The opener, as made by Messrs. Platt Brothers and Co., Limited, is shown in perspective in Fig. [14]. The cotton enters the opener chamber by the tube, as described, and is at once acted on by the cylinder, which revolves horizontally. The cylinder is surrounded by grids, against which the cotton is thrown, and through which the dirt is ejected. The forward movement of the cotton is induced by the exhaustion of the air, produced by means of a pair of fans, placed one at each side of the machine and adjoining the exit orifice from the cylinder chamber. Power of lateral adjustment is given to these fans, so that they may be set in towards the centre of the machine to a greater or less extent. In this way the stream of cotton, as it issues from the cylinder, is directed on to the cages as required, and a very even lap or sheet is thus obtained. It is obvious that the guiding power of the air current is the right thing to rely upon, and, by the arrangement described, ample regulation of it is obtained. A lap which is even in thickness is absolutely essential to good work, and the arrangement of fans in the way described ensures this being obtained. The author recently saw the first lap made on a machine of this type in a large Oldham spinning mill, and the regularity of the thickness and evenness of the selvedge was very noticeable. The machine as shown in Fig. [14] is a combined one.

(53) The Crighton Opener is a machine the distinctive feature of which is the employment of a vertical conical beater. A sectional elevation of the machine as made by Messrs. Crighton and Sons is shown in Fig. [15]. The beater consists of a number of cast-iron discs D securely keyed upon a vertical shaft, which is sustained at its lower end by a bearing E in the frame F, and at its upper end by the bearing A. On the discs are fastened steel blades, and it will be noticed that their diameter increases from 18in. to 33in. Surrounding the beater is a casing B, in which are a number of longitudinal slots, the inner surface of the grids being in most cases made of the shape shown in section in Fig. [16]. A recent improvement by Messrs. Crighton and Sons is shown in Figs. [17], [18], and [19].

Fig. 15.J.N.

Fig. 17.

(54) The cotton is fed by the tube placed at C, and a fan is fixed just below the entrance of the tube into the beater chamber. The direction in which the cotton enters and the positions of the fans are important points of construction. The feed tube is not fixed in a straight line, but is slightly curved so as to direct the cotton upward as it enters the beater chamber. As it enters it comes in contact with the serrated surface of a truncated conical dish, within which the lowest arm D of the beater revolves. Immediately below this dish a fan disc of the Schiele type is fixed in machines in which a combination of feed table, air trunks, and opener is made. The object of this fan is to exhaust the air in the tubes up to that point, and draw the cotton forward until it reaches the cylinder. There is a decided advantage in this arrangement over one in which the fan is placed beyond the exit orifice at the top of the opener chamber. In the latter case the air is required to draw the cotton through the dust trunks into the opener, upwards past the cylinder, and so on to the cages. In the machine as made by Messrs. Crighton, the fan at the bottom of the dish is sufficient to bring the cotton to that point, and all that is subsequently required of the fans placed beyond the cylinder is to lift the cotton upwards during its progress through the beater chamber. On this account a slower moving current of air can be employed, and the fans connected with the cages can be revolved at a less velocity. The full advantages of this arrangement will be afterwards pointed out, but as the cotton is raised slowly while being beaten, it is thoroughly opened and cleaned.

Fig. 16.

Fig. 19.

Fig. 18.J.N.

(55) When the cotton enters the beater chamber it is at once struck by the blades of the beater, which revolve at a speed of about 1,000 turns per minute. The peripheral velocity of the blades is thus at the bottom 4,712 feet per minute, and at the top 8,639 feet. The blow thus given disentangles the cotton and flings it against the inner surface of the grid, thus momentarily arresting its motion. As the beater revolves, the cotton continues to find its way upwards, and in its course is repeatedly struck by the blades, which, as has been seen, have a continually increasing peripheral velocity as they near the top. In this way, as the cotton nears the exit orifice, which is placed at the upper part of the machine frame, on the opposite side to the tube C, it is thoroughly beaten into a fleecy condition, with its fibres well disentangled.

(56) The shape of the grids surrounding the cylinder is an important matter. In the form illustrated in Fig. [16], the projections on the grid are triangular in shape, and have slots between each pair through which the dirt can freely pass. It will be easily seen that the shape of these grids is one which will only exercise a little clinging effect upon the cotton, which, as it is impelled by the stroke of the beating blade, will very readily roll pass the projections. As the rapid rotation of the cylinder tends to slightly compress the air, the latter finds an outlet if possible. This is the object of the slots in the grid casing, and they fulfil it very well. But there is always a liability that along with the air and dirt—which also passes the grids—a little fibre may escape. It is desirable to avoid “fat droppings” as they are called, and the grid shown in Figs. [17] to [19] has been designed for this purpose. Each of the pockets C Fig. [18] shown becomes a resting place for the opened fibre, and as its lower end C² is open, the dirt can fall freely. In order that the air can easily get away, between each pair of pockets a small slot is formed, and in this way there is no downward impulse given to the cotton while held in the pocket. Thus each blow given to the material opens it, drives it into the pockets where it dwells for a short time, and from which after the passage of the beater blade A, it is drawn by the suction of the air. By this system there are given short periods of rest, which very materially facilitate the fall of the dirt.

(57) Instead of feeding the opener manually as shown in Fig. [15], a lattice feed can be adopted. Among the many important points in connection with the Crighton, or, as it is sometimes called, the “exhaust” opener, none is more so than the construction and lubrication of the footstep. This is arranged so that the foot of the beater shaft revolves in a constant bath, either of oil or water, and great care is taken to cover it so as to prevent the entrance of sediment or dust.

(58) In Fig. [20], a longitudinal section of the machine as made by Messrs. Lord Bros., is given, and is accompanied by a plan of the same machine as combined with a porcupine feed. Referring first to the plan, the lattice feed A delivers the cotton to the porcupine roller C, by which it is passed in a partially opened condition to the air trunks D. By these it is conducted to the opening chamber F, being admitted to it by flap valves G. The cotton enters the chamber F by the tube H, terminating in the dish I. The exit orifice is placed at the top of the chamber F, the course of the cotton being shown by the arrows. The cylinder is similar to the Crighton, but the blades E are fixed in malleable iron arms L fastened to the shaft, and can, after wear, be reversed. Below the foot of the shaft, and within the bearing O, is a loose washer P, which can rotate with the pressure of the shaft, this arrangement considerably lessening the wear. At each side of the exit of the delivery tube, fans N are fixed, which, like those in the Platt machine, can be adjusted sideways for the same object. The cotton then passes over grids R on to the cages T, from whence it passes through the scutching beater W to another pair of cages S, as indicated by the arrows, and is finally formed into a lap as shown. The special construction of the beaters enables the cotton to pass freely upwards, and prevents any stringing occurring. The speed of the beater in this machine is 520 revolutions per minute for American cotton, and 720 for Indian. The slower velocities used necessarily imply the use of less power.

(59) There are one or two points to be noticed in concluding the consideration of the Crighton type of machine. The distance from the face of the grids to the ends of the beater blades should be carefully arranged to suit the class of cotton treated, as, if it is too great, the opening is not properly effected, and, if too little, the cotton is liable to be damaged. The rate at which the feed is conducted should always be carefully watched, because, if the material is passed in too quickly, its bulk becomes so great in the lower part that the dirt cannot fall freely, but is received by the entering cotton. Cleaning is not, therefore, so effectually carried out. In addition to this, it is desirable that the cotton should be allowed to assume a perfectly open condition, which it would do with difficulty if the space were overfilled. Cotton has been passed through, for a short time, at the rate of 110,000lbs. per week of 60 hours, but for the reasons stated, 30,000lbs. is ample.

(60) It might be thought that the pitch of the projections on the inner surface of the grid should be as small as possible, but this is a mistake. It is essential that the cotton should strike not merely the top or apex, but one face or side of the projection, if the full cleaning effect is to be obtained. It is obvious that if the pitch is too fine no such face blow would be given, and very inefficient purification would occur. The considerations thus stated are founded on actual experience in working the machines, and should be borne in mind in constructing or controlling an opener of this type.

(61) It is considered by some makers to be advisable when using this style of machine to employ one with two beaters revolving in separate chambers, connected to each other by an air pipe. This is more especially the case when Indian or short stapled cotton is used. When the double machine is used, the conducting tube between the two leaves the first chamber at the top, and enters the second at the bottom. The driving of the opening machine is usually obtained from a counter shaft, by which means the speed of the driving pulley becomes a moderate one.

(62) A machine, of which large numbers have been made by Messrs. Lord Brothers and Howard and Bullough, has a conical beater placed in a horizontal position, and the opener proper is usually combined with a scutching and lap machine. As this type of machine is very similar in its general principles to that previously described, and is not now so largely made as formerly, it is not necessary to give a detailed description of its mechanism.

(63) It has been repeatedly stated that the various machines are united by means of tubes, so that the cotton can readily be taken from one machine to another. It does not matter whether the machines are in the same room or not, or what distances separate the rooms in which they are placed. This has been shown in Figs. [6], [7], and [8], referred to in the preceding chapter, and the further arrangement is illustrated in Fig. [13]. In this case the cotton, after being delivered into the dust trunk, or tube D, on its way to the opening cylinder, may be carried two or three hundred yards, if desired, before it reaches the latter. There is, of course, a limit to the distance it may be conveyed, but it is a very wide one. There are many conveniences arising from this procedure. It is becoming a very common practice to build the mixing and scutching rooms away from the main body of the mill in order to minimise the risk of fire. But even where this practice does not obtain, the employment of air tubes is a good one, as it enables the material to be transferred from one point to another without handling. In this way the cost of labour is much reduced, and in addition the cotton is less liable to damage.

(64) At one portion K of the conducting tube D an arrangement is fitted by which a partial cleansing of the cotton occurs before it reaches the opener. Below the level of the tube a chamber nearly square in section is formed, as shown in section at the left-hand corner in Fig. [20], forming the tube into a D shape. This chamber is made of a length which is determined by the character of the material used and considerations of its position, etc. At intervals of a few inches plates are arranged so as to divide the chamber into a number of compartments, as shown by the sectional view. Over the top of these plates the material rolls in its forward movement, and a large quantity of dust, sand, and heavy impurities are deposited in the trunk. Doors are fitted to the underside of the chamber, by which the droppings can be removed at intervals as desired. The use of these grids has been attended with unmistakeable benefit, and leads to a much more effective cleaning of the cotton.

Fig. 20.J.N.

(65) By the method just described it is necessary to cleanse the trunks manually at intervals, and if any neglect occurs there is some danger of the dirt being carried forward. To obviate this, Messrs. Platt Bros. and Co. Limited have patented and applied the arrangement shown in Fig. [21]. In this case the dust chamber L is sustained in a manner arranged to suit the circumstances of the case. Instead of being fitted with the vertical plates described, an endless band is carried over two drums, one at each end of the chamber. This band K is driven from the pulley shown by means of worm gear, and receives a traverse at its top side in the reverse direction to the air current. On the band are fitted a number of blades or teeth, between which the dust or dirt can fall. The traverse of the lattice carries the dirt forward, and when the teeth are turned downward it falls into the spout or receptacle N, and on to the top of an iron flap P, usually kept in a horizontal position by the balanced lever fitted on the spindle on which the flap oscillates. The collection of a sufficient quantity of dirt destroys the equilibrium and causes the flap to tip, allowing the dirt to fall into a sack suspended below the orifice to receive it. In the event of any dirt falling on to the bottom of the chamber, two or three special blades are arranged to scrape along it and draw the dirt to the other down spout O, where a similar action occurs. This arrangement has two advantages. It constantly presents to the advance of the cotton new and clean receptacles for the dirt, and it automatically removes the latter from the path of the material. These are decided improvements, and the arrangement is a considerable advance on its predecessor.

Fig. 21.J.N.

CHAPTER V.
THE SCUTCHING MACHINE.

(66) After the cotton has been opened by any of the machines just described it is passed into a machine commonly known as a “scutcher.” In this it is subjected to a further beating action, which in this case, however, has the object of cleansing rather than opening it. Machines of this class may be either single or double, that is, the cotton may in passing through the machine be subjected to the action of one or two beaters. Occasionally, but very rarely now, three beaters are used. It is becoming a more general practice to use an opener and single beater combined as a first stage and a single beater machine as a second stage, but there is no fixed rule in this respect, the actual facts of each case determining the procedure. At one time the opened cotton was ejected in a loose condition from the opener, and was placed upon the scutching machine feed-table by hand, often being weighed. As an English practice this is becoming obsolete, the system of pneumatic suction being employed to convey the cotton from one machine to another. Openers have very often attached to them a lap machine, which forms the cotton into a roll or “lap.” As the “lap” attachment is one which is common to most cleaning machines a description may be given of it at this point.

(67) This attachment consists of two fluted rollers (L L Fig. [22]), which are suitably revolved, and on which the roll of cotton M is formed, being lapped round a rod or tube by the frictional contact of its surface with the rollers L. Before it reaches this point the cotton is formed into a sheet on the dust cages, as described in the preceding chapter. The iron rod or tube is made long enough to act as an axis for the lap to revolve on, and to enable it to be carried about from place to place for further treatment by succeeding machines. As the sheet or fleece leaves the dust cages J it is passed between a pair of smoothly turned rollers, the upper one of which is weighted so as to calender or compress the lap. This is a matter of some importance, as it renders the surface of the lap smoother and prevents the various layers adhering to each other when unrolled. An arrangement is fitted by which the attainment of a defined diameter of lap releases the setting on handle, causing the latter to move and transfer the strap on to the loose pulley stopping the machine. The importance of forming laps is now well recognised, and will be dealt with at greater length at the end of this chapter.

(68) Fig. [22] represents a side elevation of a single scutching machine, as made by Messrs. Lord Brothers, that is, one which beats the cotton once. It contains a revolving beater A, fixed upon a central shaft and driven at a high velocity from a counter shaft. The beater consists of arms, forged solid, with a central boss, and having feet at their outer ends. The arms are keyed firmly on the shaft, and may be either round or elliptical in shape. There are either two or three arms on each boss, and a number of them are secured to the shaft along its length within the beater case. According to its construction the beater is known as a two or three “winged” beater. However made, it is carefully shaped and machined, so as to be in perfect balance, and this is a most important point in the construction of the machine. Too much stress cannot be laid on the necessity for extreme care in this matter. Not only should the beater arms be balanced prior to fixing, but after having been keyed on the shaft the same operation should be carried out. In order to balance the beaters thoroughly it is better to revolve them rapidly, while sustained in bearings having freedom of sliding movement in a frame. The velocity at which they are tested should be considerably in excess of that at which they work, and no pains ought to be spared to get the beater in absolutely true balance when working. Otherwise the vibration set up would be considerable, and the character of the blow given would be intermittent instead of regular. Before the final balance is given the blades should be attached to the arms. The blades are made of steel—or of a combination of steel and iron fused together—of an irregular section, angularly formed at one side, so as to present a moderately sharp face to the cotton as it strikes it. The blade requires to be made with a slight clearance, so as not to rub the cotton after striking it.

Fig. 22.J.N.

(69) The question as to which is the better form of beater to use—a two or three-winged—is one which is difficult to answer. Most makers to-day are using the former, while others—as for instance, Messrs. Platt, Brothers and Co.—while employing a two-winged beater for the “breaker,” use a three-winged for the “finisher” scutching machine. From the constructor’s point of view the two-winged beater has undoubted advantages, as it is at once more easily made, and balanced with much less difficulty. The diameter of a two-winged beater is usually 14 inches across the blades, and of a three-winged 16 to 18 inches. The velocity of the former is greater than that of the latter, being in one case 1,200 to 1,500 revolutions per minute, and in the other 900 to 1,000. Thus the peripheral velocity of the two-winged beater is from 4,314 to 5,497 feet per minute, and that of a three-winged, 4,100 to 4,700 feet per minute. Although a three-winged beater, running at 1,000 revolutions, will strike the cotton 3,000 times per minute, the two-winged form, running at the higher velocity of 1,500 revolutions, will give the same number of blows. There is, however, the character of the blow to be considered. The smaller diameter in the case of the two-winged enables the higher velocity to be reached, and the blow given is sharp and quick. In addition to this, the smaller circle described by this form of beater causes the blade, after having struck the cotton, to leave it rapidly; whereas the larger diameter of the three-winged one leads to the blade being longer in contact with the cotton than it otherwise would be. This, coupled to the comparative slowness of its peripheral velocity, gives a dragging blow, which is not a good thing for the cotton, as it is apt to crush or bruise the fibres. The longer the staple the slower the velocity of the beater should be, and this has an important bearing on the subject. For instance, with good cotton, the velocity of a two-winged beater is sometimes reduced to as low as 1,000 revolutions, while with Indian cotton the higher velocity is preferable. These considerations tend to show that the two-winged beater is the most suitable.

(70) There is another point which, however, deserves a word or two. The regularity of the pulsations of a scutcher beater is a matter requiring consideration. It is a subject not always thought of, but it has a great influence upon the resultant lap. The cotton—as will be hereafter shown—is struck from a roller or pedal, and is thrust into the range of action of the beater blades at a defined and regular rate. As it is desirable to beat it into small tufts before flinging it on to the grids, and as the cotton is liable to damage if the pieces struck off are too large, it follows that the oftener the blades strike the better. That is, of course, assuming they do not strike so often as to powder or crush the fibre. Now, there is no reason in this consideration, for the employment of a three-bladed beater, which does not strike the cotton more frequently than is the case with one with two blades.

(71) It is usual to form laps at the termination of each scutching process. These are first made, in most cases, on the opener, or failing that, on the breaker scutcher. The laps thus made are fed to a second machine called the finisher scutcher, where a new lap is made, which is fed to the carding engine. It is therefore desirable to obtain the utmost regularity in the last lap named, and for this reason the pulsations of the beater become important. On this account Messrs. Platt Bros. and Company use a three-winged beater in their finisher scutcher, believing that the result is more satisfactory.

(72) Surrounding the beater at its upper portion is a case, made quite air-tight. Beneath the beater a grid H is placed, the bars of which are set to present a sharp edge to the cotton. The number of these varies according to the class of cotton used. Careful regard should be given to this factor. In fixing the bars they should be placed as shown in Fig. [24]. The front bars C should have their cleaning edges set a little in advance of a perpendicular line drawn across an imaginary line horizontal to the axis. The angularity thus given should decrease as the bars are further from the feed roller. The reason of this is obvious. As the cotton is struck from the feed rollers it is desirable that it should receive a sharp check at once, in order to shake out the freshly-freed impurities. This requirement becomes less urgent as the cotton passes onward and the arrestment of its traverse is less necessary.

(73) The circle described by the top of the bars should not be concentric with that of the beater blades, but ought to be as shown in Fig. [24], further from the centre of the beater shaft at the back than it is at the front of the grid. The reason for this is that the bulk of the cotton after being scutched becomes greater, owing to its more open condition, and it naturally requires more room, to avoid any choking or entanglement. Further, if the grid is comparatively long the distance between the bars—in other words, their pitch—must be increased. Below the bars is a chamber into which the dirt can fall freely, and which is closed by doors from without. The pitch of the bars should be large enough to permit of the easy passage of the dirt.

Fig. 23.J.N.

Fig. 24.

(74) Messrs. Howard and Bullough use, in addition to the fixed bars shown, the additional bars D, which are pivoted at their lower end, as shown, in a movable plate. This plate is attached to a lever E, which can be operated from the outside. The purpose of these bars is to admit of the admission of more or less air as desired. The space below the fixed bars and that below the air bars are separated by a thin division plate F. It is claimed for this arrangement that the fall of the dirt through the bars C is considerably facilitated.

(75) After passing the dirt grids, the cotton falls on to a second grid, or plate, as preferred, and then between a short “dead” plate and “beater sheet” to the cage J on to which it is drawn. The cage J consists of a skeleton cylinder revolving on a shaft, and having its periphery formed of finely-perforated sheet metal. Each end of the cage terminates in an air passage or trunk extending upward as shown. At the foot of the trunk the fan I is placed, which exhausts the air through the cages, and sucks the cotton on to them so as to form a continuous sheet or fleece. From the cages the fleece is taken to the lap attachment, which has been previously described.

(76) Messrs. Crighton and Sons, a perspective view of whose machine is given in Fig. [25], make their cages in a somewhat different manner to that just described. The ends of the cages are fitted into the framing, which is recessed at each side to receive them. Their peripheries are formed of woven wire webbing, instead of the perforated zinc sheets mostly used. At the end of the cage the webbing is protected by a brass ring, which keeps it firmly in position. The effect of this arrangement is two-fold. A greater space is left for the passage of the air than is possible with a perforated metal covering, and as a result, the intensity of the current is reduced. In addition to this, the fleece of cotton is laid on the whole of the face of the cages, because the manner in which they are fitted into the framing practically causes the latter to act as a guide, beyond which the cotton cannot spread. In this way the edge, or “selvedge,” of the lap is rendered very even, a subject the importance of which is further dealt with in paragraph 99.

Fig. 25.

(77) Another point of special construction, adopted by the same firm, is the position of the “dead plate.” This is the name given to a plate below which the scutched cotton travels, extending across the machine immediately behind the beater. As the cotton leaves the range of the beater, it falls upon a plate or sheet called the “beater sheet,” immediately below the “dead plate.” Now, for reasons to be given, the position of this plate is important, and in the machine as made by Messrs. Crighton, its distance from the beater sheet is 2¹⁄₂ inches. Immediately beyond this point the same firm use an appliance known as a “leaf extractor,” of which an illustration is given in Fig. [26]. It consists of an endless brattice or canvas band D, as wide as the space between the frames, and having fastened to it transverse bars of wood B. These are shaped as shown, with an edge meeting the cotton as it moves forward, thus scraping off the leaf, and the space contained between each pair of these practically forms an air-tight box for the reception of the leaf. The brattice moves in the direction of the arrow, and thus meets the cotton as it passes from the beater. It is kept in tension by means of the rollers E F and G, and as the bars pass over E, which is unattached, its weight causes them to open, and so drop the leaf into the chamber below. Having thus described the mechanism of this special arrangement, it is necessary to say something of the draught regulation and the effect it has upon the work.

Fig. 26.J.N.

(78) The regulation of the air current is one of the most important features in the working of a scutcher. Other things being equal, it is not too much to say that success or failure largely depends upon it. On the one hand, it is necessary to provide sufficient suction to draw the cotton forward and lay it evenly on the cages; on the other, an excess of suction is very detrimental, as, if the movement of the cotton is too rapid it will be drawn over the dirt grids before instead of after the dirt and leaf has fallen. More especially for the sake of the removal of leaf does the current require to be slow. With any other procedure the lighter matter cannot fall, and is carried forward to the cages. An excess of suction further results in the cotton fibres being drawn into the interstices of the cage surface, and the fleece does not in that case leave the latter easily. This results in a rough surface of the lap, and leads when it is rolled up to “licking,” or adhesion of the different layers.

(79) It is therefore desirable to get the draught as nearly balanced as is consistent with the required onward movement of the cotton. What is wanted is rather a large volume of air moving at a slow pace than a smaller one travelling more quickly. The fan should therefore be as large as can be conveniently arranged, and should be run at a comparatively slow velocity. Its exit orifice must be of ample size, and no obstruction be presented to the current of air. The latter is delivered into a passage or conduit running below the floor and terminating either in the open air or a specially-arranged chimney. All these passages must be made of ample size, and cases are numerous in which neglect of this requirement has resulted in the inefficient working of a machine which otherwise ought to have worked well. The atmospheric changes render it necessary to watch the regulation of the current so as to suit them, within limits.

Fig. 27.J.N.

(80) The precise effect of the arrangement of the dead-plate and beater-sheet referred to in paragraph 77 is to decrease the work thrown upon the fans. The beater, by reason of its rapid rotation, creates a sufficient current to carry the cotton on to the grids or extractor, if the space between the dead-plate and sheet is narrowed as described. If that be increased the effect of the impulse thus given is diminished proportionately. When so arranged, the cotton impelled as described passes gently over the leaf extractor, being aided by the slow current created by the fans, and thus allows the leaf to fall freely and without difficulty.

(81) In Fig. [27] a diagrammatic representation of Messrs. Platt Brothers and Company’s arrangement is given. In this case, also, the dead-plate is arranged so as to narrow the exit orifice from the beater, with a similar beneficial effect to that described. The cotton then passes over the bars of a dirt box L, into which the leaf can fall, being periodically removed.

(82) The feed apparatus used is now almost universally combined with a regulator which bears the name of its inventor, the late Mr. E. Lord, of Todmorden, and is commonly known as the “piano feed.” It is one of the most effective motions in the whole range of textile mechanics, and has considerably increased the regular working of this particular machine. Referring now to Figs. [28] to [31], which are respectively side, end, and plan views, it will be seen that the cotton is fed from the lattice H over the nose of the pedal lever A and under the feed roller B. After this it is struck by the beater G in its rotation. The shape of the pedal nose varies considerably, according to the length of the cotton used, the modification in Fig. [28] being that used for short, and the one in Fig. [29] being employed for long stapled cotton. The pedal lever is hinged upon a rod, and has behind its fulcrum a long tail piece which terminates in a hook I. On to this a pendant lever C is suspended. The lower portion of each of these pendants is widened so as to form a double taper surface, as shown in the end view at D. Between each pair of pendants, at its lower end, small runners or bowls are placed, these being fixed in rods sliding in the double frame F, which at the end E is tied together. The last of the series of pendants C¹ is formed with a slot, as shown, with which a lever is jointed, as will afterwards be described, and as is further shown in Fig. [23], which is an end view of the machine shown in Fig. [22]. All the pendants can swing freely upon the pedal levers. The latter are placed, as shown in the plan, in close proximity to each other, so as to cover the whole space below the feed roller, while at the same time they have freedom of movement.

(83) Referring now more particularly to Figs. [22] and [23], the last pendant lever is coupled by the connecting rod O and the levers shown to the two strap levers E, which have sectors formed at one end gearing with each other. These levers carry the guides for the strap N, which is tightly placed upon the cones D D¹. These are respectively convex and concave, their outline being a parabola. The cone D¹ is driven by means of the strap shown from a pulley on a counter shaft, and revolves at a velocity of 600 revolutions. The other cone D is driven from D¹ by the strap N, and is fixed upon a spindle or shaft which is carried upward (Fig. [23]). On the upper end of the shaft is a worm P engaging with a worm wheel R on the feed roller, which is driven by these means, or a change wheel may be interposed if desired.

(84) The action of this mechanism is as follows. As the cotton is delivered by the lattice it passes over the nose of the pedal and between it and the feed roller. If there happens to be a thick piece in the feed it depresses the nose of the pedal over which it passes. This raises the pendant rod C. Now the space between the thinnest portion of the pendant foot and the bowls is only sufficient to enable the pendant to rise a little before pressing on the bowl next it. Its motion being limited in this way, and the tendency to rise still occurring, either the pendant must become jammed or the bowl must have liberty to move to one side. This is what occurs, the lateral movement of the bowl being permissible to the extent which corresponds to the space between the remaining pedals and their adjoining bowls. After this is taken up, pressure exercised by the rising pendant upon the bowl causes the bar in which the latter is fixed to move in the box to an extent which is regulated by the depression of the pedal nose. In other words, the pendant swings on the end of the pedal lever either to the right or the left as may be required, giving a similar movement to the rest of the series. The movement thus set up is communicated to the strap levers E by means of the connecting rod O and its attachments, and the strap is accordingly raised or lowered as required by the circumstances of the case. The weight of the parts connected to the pedal levers are sufficient to press their noses against the feed roller unless prevented by means of the cotton being fed. Thus a thin place in the material at any part of the width of the feed roller is followed by the reverse action to that named, the strap being moved on the cones in a similar manner. The presence of a thick place in the feed decreases the velocity of the driven cone and feed roller, while the reverse action occurs when a thin place is presented. Thus the retardation of the cotton in the one case leads to any extra thickness being rapidly beaten out, more blows being given to the same length fed than would be under ordinary circumstances. On the other hand, a thin place results in the quickening of the feed roller and a greater quantity of cotton is beaten off in the same time. In this way an evenly-weighted delivery takes place, and this, in conjunction with the lap feed, of which more will be said hereafter, enables a lap to be finally produced, in which the variations of thickness are comparatively slight.

Figs. 28, 29, 30, and 31.J.N.

(85) At one time it was the universal custom to strike the cotton directly from the pedal nose Fig. [32], a practice which, however the latter was shaped, had many defects. A much better method is adopted by Messrs. Platt Brothers and Company, and is shown in Fig. [33], which illustrates the new practice. It will be seen that, when the beater strikes the cotton directly from the pedal nose, the fibres will be bent sharply round an angle. In the case of long-stapled cottons especially this is detrimental, as it is liable to lead to rupture or breakage of the fibre. With the shorter-stapled varieties this is not so likely to occur, and the use of a pedal and feed-roller is more permissible. The arrangement shown in Fig. [33] is a much better one, and consists in the employment of an additional pair of feed rollers placed between the pedal and the path of the beater. There are two distinct advantages from this procedure. The cotton is bent round a larger curve when it is struck by the beater, and is, therefore, less liable to rupture; and the feed-rollers exercise a certain amount of drawing action. The latter point is of some value. The cotton in passing under the feed roller and between it and the pedal nose is held by them. The correction of thick or thin places and the alteration of the speed of the feed to meet them is controlled from this point. If the second set of rollers revolves at a slightly quicker speed than the one above the pedal the cotton will be a little drawn. In any case, this action will take place to a greater or less extent, and the thick places will thus be partially thinned out before being struck by the beater. The shock of the stroke is thus considerably diminished, and the risk of damage much lessened.

Figs. 32-34.J.N.

(86) It only remains to be said with regard to the Lord pedal motion shown in Figs. [28] to [31] that it is now amended by the introduction of two bowls between each pair of pendants, which are acted upon singly by the pendant they adjoin. The latter point is illustrated in Fig. [34], which represents the old method of arranging the pendants and rollers, and an improved plan of Messrs. Howard and Bullough. In the former case each pendant engaged with one side of a bowl, with the other side of which the adjoining pendant also engaged. In the event of both of the latter rising at once, it is apparent that the bowl will tend to be rotated in opposite directions. In effect it becomes practically inoperative, and the friction set up is considerable, preventing the easy movement of either pendant. To obviate this, the three-bowl arrangement shown in Fig. [34] is adopted. The pendants are made with one flat face, and with one on which a rib is formed. On the spindle three bowls are placed, the centre one being of smaller diameter than the others. The two outer bowls engage with the flat side of one of the pendants, but are entirely out of contact with the adjoining one. On the other hand, the central bowl engages with the rib formed on one pendant, but is too small in diameter to engage with the flat face of the next of the series. Thus the whole of the pendants could rise simultaneously without setting up the friction referred to owing to the cross torsion on the rollers. The sensitiveness of the motion is thus largely increased. The adoption of two bowls, each independent of and out of contact with the other, produces a similar result.

Fig. 35.J.N.

(87) There are several modifications of the pedal motion in use, but, before passing on, the arrangements used by Messrs. Platt Brothers and Company may be described. Dealing first with the driving of the cones reference may be made to Fig. [35]. The spindle of the driving cone B is prolonged so as to rest in a footstep and has fixed upon it the double-grooved pulley S. An endless rope or band is passed round the pulley I, which is the driving pulley, and thence passes round the pulley G, carried on a pin, the position of which can be regulated by the screw shown. After going once over the pulley G the band is conveyed round the upper groove of the pulley S, back to G, thence to the carrier pulley shown, again round S, and finally returns to the driving pulley I. A little consideration of the course thus followed will show that there is a pull upon the spindle of the cone B in diametrically opposite directions, and as the pull is in each case equal, the wear of the shaft and footstep is materially reduced. The consequence is that high velocities can be attained with the utmost ease, and without any undue strain upon the ropes or shafts.

(88) Referring now to Fig. [36], which is a front view of the pedal arrangement, it will be noticed that the levers P are each of them placed between two bowls, which are actuated by their own pendants only. Instead of coupling the regulating levers to the last of the series of pendants, a different arrangement is adopted. The hanging lever O is fastened at its upper end on a pin carried by the horn bracket shown, which is fixed to the bowl box. On the other end of the pin is a second lever, shorter than O, and also fixed to the pin. Thus any oscillation of the lever O is followed by a similar movement of the second lever. The lever O is long enough to enter the bowl box, and any lateral movement of the bowls causes a similar movement in the lever. This is repeated by the shorter lever, which is coupled to a connecting rod Q. The latter is made in two parts, connected by a nut, with a right and left handed thread, so as to permit of any adjustment necessary, which is also aided by the slots shown as existing in the various levers in the series. The rod Q is jointed to an L lever R, on the horizontal limb of which the balance weight T is fastened by means of a pin passing through the slot. To the extremity of this limb of the lever R a chain F is coupled, which, passing over a grooved pulley placed above the cone box, is attached to each of the strap levers O P (Fig. [35]). These levers are hinged in the manner shown, and carry strap forks acting upon the strap C. The relative positions of the strap and levers, at a point midway of the length of the cones, are shown by the dotted lines in Fig. [35]. On the spindle of the cone A is the worm L, by which the feed rollers are driven, the three roller arrangement being in this case used, one of them revolving above the nose of the pedal lever.

Fig. 36.J.N.

(89) The action of this mechanism is easily explained. As the pedals are depressed or elevated the bowls are moved laterally, as previously described. The last of the series being in contact with the lever O causes it to oscillate, and, in consequence, the shorter lever jointed to the rod Q is moved. This motion is communicated to the chain F, which exerts a pull upon the strap guides, and raises or allows them to fall as described. One cardinal feature in this arrangement is the power of adjustment which is given at every point, the balance weight T being easily set to give the exact amount of pressure of the lever O upon the last bowl, while at the same time permitting it to oscillate without an excessive power being required. This makes the motion very sensitive, which is assisted by the size of the cones, and by placing the pedals on knife-edged supports instead of a shaft. Usually the cones are made about 4 inches diameter at the large end and 2¹⁄₂ inches at the smaller. In the machine, as made by Messrs. Platt, the cones are 8 and 5 inches diameter respectively at each end, and, as their velocity is high, a slight pull upon the strap vertically is sufficient to move it up or down the cones.

(90) A special arrangement, made by Messrs. Dobson and Barlow, is shown in Figs. [37] and [38] in elevation and plan. Here the pedals W W¹ are all of the same shape, and the last of the series W is not coupled to a connecting rod, as shown in Fig. [22]. Instead of this, three bowls, R R T, are placed upon a pin which passes through the forked end of the small frame Z. The rollers R R roll in the groove in the box, and are provided with broad flanges which keep them in position laterally. The roller T is in contact with one edge of the last pendant W, and when the latter is pushed to one side it presses upon the roller and causes it and the cradle Z to move in the same direction. A pin in the other end of the cradle passes through the end of a lever Y, which fits between the fork in Z and passes through a hole in the cross-piece of the bowl-box. The thrust upon the rod Y is therefore given in the centre of the pendants, and these are not liable to be twisted. The rod Y is jointed to the L lever shown, which forms part of the series connecting the pedals and strap guide levers. As shown in the detached sectional view, Messrs. Dobson and Barlow employ between each pair of pendants three anti-friction bowls, U V U, which work loosely upon the pin X. The latter is made in the centre with a boss, eccentric to its main portion, and in this way the central bowl V is caused to engage with the pendant W, while the other two U engage only with the pendant W¹. The pin X cannot revolve by reason of being fitted into a square hole in one of the bowls sliding in the groove in the box, so that the relative positions of U and V are always maintained.

(91) In Figs. [39] and [40] a front and side elevation of the pedal regulator as made by Messrs. Asa Lees and Co. Limited, is illustrated. The pedals E are hinged at one end, and rest upon vertical rods J, the lower ends of which press on the extremities of the balanced plates B. Each of these is suspended on a larger plate C, of similar construction, which in turn rests on the extremity of a plate D. The latter is suspended by its centre from a lever, F, which is fulcrumed on a knife edge at H. The lever F is coupled in the manner shown to the strap guide lever I, which is moved by means of the horizontal bar shown, which slides upon guide runners. The cones A A¹, are placed horizontally, the advantage claimed for this position being that the strap has a much easier motion along the cones than is the case when the latter are vertical. It will be observed that the whole of the balanced plates are in equilibrium, and are suspended on the end of the lever F. Thus a slight movement of one of the smaller plates, B, is multiplied before it acts upon the lever F, and the regulation of the strap is thus rendered more sensitive.

(92) In Fig. [41] a side elevation of the driving gear used by Messrs. Asa Lees and Co. is shown. In this case the whole of the essential movements are driven by means of one endless rope. This plan obviates the difficulties which arise if a beater strap breaks and the feed continues, or if the delivery ceases from the same cause and under the same circumstances. In this case the lap attachment and cages are driven from the pulley D, the beater and the cones also by the same rope. The direction of the rope’s movement is indicated by the arrows, and a tightening screw is provided to keep the band in tension. On the shaft of the beater is a friction clutch, one-half of which is formed into a grooved pulley. By disconnecting the clutch, the beater can be stopped independently of the rest of the machine.

Fig. 41.J.N.

Figs. 37 and 38.J.N.

Fig. 39.

Fig. 40.J.N.

Fig. 42.J.N.

Fig. 43.J.N.

(93) Having thus described the principal methods of arranging the mechanism adopted by various machinists, there are one or two words to be said with reference to combined machines. These are very numerous and various, being arranged in several ways to suit the requirements of particular spinners. For instance, in Fig. [9], described in the last chapter, there is a combined machine, viz., an opener and lapper. The machine shown in Fig. [20] is an instance of a combined opener, scutcher, and lap machine. So, again, the machines shown in Figs. [13] and [14] are similar combinations, and in Fig. [8] is an example of a breaker feed combined with an opening cylinder—in different rooms but coupled by an air pipe—used as an aid in forming a stack of mixed cotton partially cleaned. In Fig. [13] a representation of the arrangement of a scutching room with a mixing room above it is given in section, and in Fig. [42] a plan of the mixing lattices. In this the bale breaker A delivers the cotton to a double ascending lattice B by which it is transferred to the series of longitudinal aprons C. Openings are placed above each bin E so that the cotton can be discharged into any of them at will. Alongside the mixing bins is a longitudinal lattice F, on to which the cotton is placed as it is taken from the stacks, and is carried to the porcupine feed table G. Immediately after being treated by that machine the material passes into the dust trunks D, over the dirt grids at K, to the cylinder of the opener H. The laps there formed are placed in the scutcher L, and those made in that machine are fed to M. The laps formed on the opener are fed to the scutchers, as shown in Fig. [22]. In Fig. [43] a plan is given of one arrangement of a scutching room, showing a complete set of machines for dealing with Indian or other dirty cotton. For long stapled clean cotton, such as Egyptian, only the two machines enclosed within the dotted lines are necessary. Most of the figures dealing with these combinations are representations of actual arrangements carried out by Messrs. Platt Brothers. It is obvious that some plan must be adopted by which the supply of cotton must be stopped when the scutching machine is knocked off. If this was not the case, the air tubes and dust trunks would speedily become full, and there would be the risk of a breakdown when the machine was re-started. In view of this difficulty, Messrs. Platt arranged that when the machine is being stopped, the porcupine feed roller is stopped so much before the opener cylinder that the whole of the cotton delivered by it is drawn out of the dust trunks. Conversely, when the machine is being re-started, the feed mechanism is the first to begin operations, so as to ensure an ample supply of cotton to the cylinder, and thus avoid any thin places or failure in the resultant lap. This is a matter of some importance, as upon it depends very largely the regularity of the laps.

(94) It is of extreme importance to produce laps at an early stage, as they play a great part in effective spinning. Before dealing with this point a few words may be said about the necessity for care in feeding the cotton. The fibre is easily ruptured, more especially at the points, which, owing to their distance from the seed during growth, are often solid. It is conceivable that the cotton might be fed at precisely the same speed as that of the periphery of the beater blades. In that case it would simply pass through the machine without any treatment whatsoever. Or it might be fed so rapidly that the beater in its rotation would knock it off the end of the lap in tufts or lumps. As the blow of the beater is given transversely of the fibre, such a treatment would produce a large amount of broken fibre. It is, therefore, of importance to feed so that the cotton is neither broken by overfeeding or pulverised by underfeeding, and in fixing the right velocity the length of the fibre requires carefully taking into account. The conditions of successful and economical work are well known, and may be stated as follows: The blow given must be sharp, and not dragging; the beater blades must be shaped to detach, without rupturing, the fibres; the rate of the feed roller must be regulated to insure the thorough detachment of the material; and, finally, the cotton should not be struck from a sharply angular surface. It is, of course, impossible so long as revolving beaters are used to avoid bending the fibres, but it is quite possible to so shape the surface from which they are struck as to minimise the risk of damage.

(95) The various illustrations given of both opening and scutching machines show that it is the practice to form the cotton at as early a stage as possible into a lap. Not only is this course more convenient, but it is decidedly preferable where good work is required. In cases where it is the custom to eject the cotton from the opener in its opened condition, it is necessary to lay it on the feed lattice of the scutcher, either manually or by means of a lattice. A practice which is now almost obsolete is to weigh the cotton by means of scales adjoining the feed apron, and spread it on the latter by hand. Even with expert attendants, the risk of uneven feeding by this plan is great, and uneven feeding means unevenly-weighted laps as a result. By the exercise of a little care, and more especially if the piano-feed be fitted to the opener, a lap it produced on that machine the inequalities of which are much reduced. The author recently saw a lap, paragraph 52, produced on the combined feed, opener, and scutcher of Messrs. Platt, which was the first made on the particular machine employed, and which was remarkably regular in thickness. The same result has been seen in other cases, and by obtaining a regular sheet at this early stage many advantages arise. Whether an opener be employed in conjunction with a breaker scutcher or not, the formation of a lap is a great help to good work. Where such a combination exists, it is customary to fit pedal regulators immediately before the scutcher beater is reached, so that the inequalities existing in the sheet as it is taken from the first pair of cages are at once corrected. A reference to Figs. [10] and [20] will show this application fitted respectively to the opener feed and the scutcher beater.

(96) Whatever may be the practice with regard to the opener, the breaker scutching machine is invariably provided with the lap attachment, and the finisher scutcher is fed from laps. A reference to Fig. [22] will show that the machine is fed from three laps F, which are laid upon the travelling lattice apron G. The forward movement of this lattice unrolls the laps and delivers them to the feed rollers, they being prevented from moving forward by the rods through their centres, which press against the vertical projections on the lattice frame. It is often customary to use four laps instead of three, especially in passing them through the last machine.

(97) It will be apparent on reflection that the laps as produced will vary considerably in weight and substance. When first formed, and taken from the machine, each lap is weighed, and a record kept of its weight. In selecting the laps from which the finisher scutcher is to be fed, regard is paid to these variations. If one or two laps are under weight to a certain extent, while others are over it to a corresponding amount, the machine is supplied with both. As they are all fed at the same time, it follows that to a large extent the irregularity existing in one is corrected by the converse irregularity of another. This is, of course, a matter of degree, but roughly speaking, the correction is an effective one. By this system of doubling, as it is called, and by the regulation afforded by the pedal motion, the lap produced finally has rarely more variation than 5 per cent., and in many cases the variation does not exceed 1¹⁄₂ per cent.

(98) There must be with a machine fed from four laps, as there is even in the opener, a considerable amount of draught existing, for it is obvious that the resultant lap will be no heavier than one of those fed, and is in most cases lighter. That is to say, the lap is elongated so that an equal length of the finished lap weighs less than that of those fed. Thus the irregularities of thickness existing in any of the laps fed to the machine are diminished by the draught of the machine, and when this factor is combined with that arising from the treatment of four laps together, the result is found in the regularity stated. It is desirable to get as many doublings as possible, and where very good work is required the material is passed through three machines before the final laps are produced. This part of the subject is so easily understood that it is not necessary to further treat it.

(99) A point which is almost as important is the necessity for getting even selvedges to the laps when produced. The lap referred to in paragraph 52 had this feature, and there can be little doubt that the regulation of the air current plays an important part in this respect. It is of the highest importance that no thin places shall be found in the selvedges, as their effect is afterwards seen through every succeeding stage in spinning. Messrs. Platt Brothers have adopted a construction of their various machines, by which a gradually decreasing width is found in each of the series. Thus, if the opener produces a lap 48 inches wide, it will be fed to a scutcher 47 inches wide only, the lap so produced being that width. A similar or greater reduction is effected in the last of the series, the width being correspondingly reduced. In this way a very even selvedge is produced, with the consequent advantages.

(100) The weight of a lap is determined by weighing one or two yards. If it be afterwards desired to see what “hank” the lap is, the weight of the piece is obtained, and the weight of a pound calculated from it. That is divided into a constant number, obtained as afterwards described, and the resulting decimal gives the hank lap.

(101) The draught in a scutching machine takes place at the following points: 1st, between the feed lattice and rollers; 2nd, between the feed and the lap rollers.

(102) It only remains to be said that by the employment of air trunks and combined machines the finished laps can be produced by the aid of only two or three workpeople. The cotton requires no handling from the mixing room till the first lap is produced, and only then requires weighing and placing upon the finisher scutcher lattice table.

CHAPTER VI.
THE CARDING MACHINE.

(103) The scutching process being complete the heavy impurities are practically removed, but there are still to be found in the material the bulk of the lighter ones. The severe treatment of the cotton during scutching adds to the number of broken and short fibres, and also increases the neps. There are also still adhering to the material small particles of broken seed and leaf, which are technically known as “motes.” The removal of all of these is part of the duty of the carding engine. In addition to this, it is requisite to arrange the fibres in what is practically parallel order, as only in this way can a strong yarn be produced. This object is attained by attenuating the “lap,” and then treating its fibres by a number of fine wire points, so as to comb or card them. The objects of carding are, then, briefly stated, three-fold—the completion of the cleansing process, the parallelisation of the fibres, and the attenuation of the fleece.

(104) Cotton was originally carded much in the same way that wool was combed, viz., by drawing a hand comb through a mass of it while held on a table or bench. As soon, however, as the manual art of spinning was superseded by a mechanical process, a similar change occurred in carding. The earliest mechanical carding engine was invented either by Paul or Bourne, about 1748, and shortly afterwards Arkwright developed his roller carding engine, which, in its essential features, is identical with many machines of the present day. A full description of the early development of the carding engine will be found in Mr. Evan Leigh’s work. The invention of the doffing comb, the revolving flat principle (by Jas. Smith, of Deanston); the coiler (by David Cheetham, of Rochdale); and the self-stripping card, all form stages in the growth of the machine. Latterly the attention of machinists has been directed to improving the mode of manufacture and the simplification of details, the main principle of the machine having been fixed for some years. All carding engines have a few essential parts which are common, and it will be better to give a general description of these before dealing with the details.

(105) The perspective view of a revolving flat carding engine, as made by Messrs. Ashworth Bros., given in Fig. [44] (page 63), will enable the description to be easily followed. The lap from the scutching machine is lifted by the iron roller on which it is wound, and the ends of the latter are slipped into the grooves formed in the brackets A. The surface of the lap rests upon a roller C, which is steadily revolved, and is geared with the feed-roller D. The sheet is drawn off the lap from the bottom, and is passed over a polished iron feed-table or plate, which at its inner end is dished. The feed-roller revolves in the curved part or dish of the plate, and is from 2in. to 3in. in diameter, being formed with longitudinal and circumferential flutes along its entire surface between the bearings.

(106) The projecting end of the lap, as it is delivered by the feed-roller, is thrust over the nose of the dished plate, and is struck by teeth fixed on the surface of a roller B, revolving at a rapid rate. The direction of the rotation of this roller is shown in Fig. [46] by the arrow. It is called the “licker” or “taker-in,” and is made of cast-iron, keyed on a wrought-iron spindle, which revolves in bearings fixed to the framing. It is driven from a pulley on the cylinder shaft by means of a crossed belt. It is usually made 8in. or 9in. diameter, and the same width as the cylinder. Its surface is accurately turned, and it is covered when ready for work with a special wire clothing, to which further reference will be made in the succeeding chapter. The licker-in teeth strike off the cotton from the end of the lap, and carry it forward until it comes into contact with the cylinder teeth.

(107) The cylinder E is made from 40in. to 50in. diameter, and from 37in. to 50in. wide. It consists of a cylindrical shell, strengthened throughout its length by small internal ribs, and having near its edges a flange formed. Its position is clearly shown in Fig. [46], and the way in which it is built in Fig. [51]. The inner part of the ends of the cylinder and the face of the vertical flanges are bored out accurately by a specially constructed machine. Into each of these recesses a spider is fitted, consisting of a central boss, arms U, and rim V. The boss is first bored to the size of the shaft upon which it has to fit, and the edge and inner face of the rim are turned to a size corresponding with the recess in the cylinder. The two spiders so prepared are fitted into their places, and are then securely bolted to the cylinder. In this way a firm and accurate fit is secured. A mandrill is fitted into the bosses, and the cylinder is then turned truly on its face. After the shaft is fitted in it is sometimes the practice to grind the face of the cylinder, but, if the needful care is taken in turning it, this is not necessary. It is essential that the periphery of the cylinder shall be rigid, but it is equally important that the latter shall not be too heavy. A velocity ranging from 140 to 200 revolutions per minute is given to it, and it is clear that lightness and perfect balance are alike important. After the turning is completed the surface of the cylinder is drilled with a number of rows of holes about half an inch diameter, into which wooden plugs are driven, so as to facilitate the “clothing” of the cylinder. As a rule the latter is balanced, or rather tested for its balance, by running it at its working speed in bearings which slide when the equilibrium is disturbed. When working, the direction in which the cylinder revolves is indicated by the arrow in Fig. [46], and the cotton is carried from the licker-in B to the doffer F, being treated on its way thither by a special set of teeth, the arrangement of which will be hereafter described.

(108) The doffer is a cast-iron roller, 22in. to 26in. in diameter, the same width as the cylinder, and is placed as shown at F. The doffer is constructed and clothed in a similar way to the cylinder. It revolves, as shown by the arrow, in the contrary direction to the cylinder, and at a much slower rate, making usually about twelve revolutions per minute. In this way the carded fibres are transferred from the cylinder to the doffer, and are placed on the surface of the latter in a thin fleece. The removal of the latter is effected by a narrow thin steel blade G, Fig. [44], known as the “doffer comb,” which is fixed on the ends of short arms fastened on a shaft carried by bearings at each end. A rapid oscillatory motion is given to the comb by means of an eccentric or cam, driven from a pulley on the cylinder by a cord or band, the number of beats per minute reaching 1,100. An arc of about an inch long is described by it, and in this way a continuous fleece, called the “sliver,” is taken off the doffer.

(109) The sliver is loosely gathered together into a strand by means of a specially shaped plate, and passed through a pair of calender rollers H Fig. [44] by which it is partially compressed. A slight traverse is sometimes given to the trumpet-shaped tube through which the sliver is taken to the calender rollers. After leaving the latter the sliver is taken upwards to an opening in the plate at the upper part of the frame I. This frame forms part of the apparatus known as the “coiler,” which is illustrated in vertical section in Fig. [45].

(110) The coiler consists of a frame I within which is a vertical shaft V driven by means of the short horizontal shaft from the calender rollers. At the upper end of the shaft a second pair of bevelled wheels are geared, which drive the calender or feed rollers placed immediately below the trumpet-shaped orifice in the cover T, which is hinged as shown. One of the rollers is supposed to be removed in order to show the arrangement more clearly. The sliver entering by the orifice in T and, passing the rollers, is delivered into a short tube X forming part of the plate Z. The latter is driven in the direction shown by the arrows by means of the spur wheel Y gearing with a rack formed on the edge of the coiler plate Z. The sliver is thus given a slight twist, and is delivered into the can W, placed on a plate free to revolve and borne in the lower part of the coiler frame. The can is placed eccentrically to the coiler plate Z, and is slowly revolved in the opposite direction to it, as indicated by the arrows. In this way the sliver is laid within the can in coils, which are peculiarly disposed so that they do not become entangled. Often, within the can, a pair of discs, coupled by a coarsely pitched helical spring, are placed, upon which the cotton is received. The object of this device is to relieve the strain upon the sliver, which would otherwise arise if it were unsupported as far as the bottom of the can. As the weight comes upon the upper disc the spring compresses.

(111) The parts thus described are common to all cotton carding machines, and would remove the major portion of the motes and heavier impurities, but only a partial parallelisation of the fibres would occur; nor would more than a small portion of the short, broken, or immature fibres or “neps” be removed. It therefore becomes necessary to devise a means by which, while the cotton is on the cylinder, it may be treated so that the completion of the cleansing and the arrangement of the fibres are carried out. In order to do this the fibres must be submitted to a combing process, by which, while held by the cylinder teeth, another set of teeth act upon them. The form of carding engine which first found extensive employment, and which is yet preferred by many spinners, is known as the “roller and clearer card.” This machine is illustrated in Fig. [47], as made by Mr. John Mason, in perspective, and in Fig. [46] diagrammatically. After the cotton has been taken from the licker-in B by the cylinder E it is carried past a roller J, known as a dirt roller. The diameter of this is from 5in. to 6in., and it revolves at about eight revolutions a minute. When the fibres are taken up by the cylinder wire, they are partially embedded in the interstices of the clothing, but the motes remain on the surface, from which they are easily removed. The dirt roller J takes these up, and, being covered with a coarser pitched wire than E, the motes become fixed in the former, from which they can be stripped. This can be effected by a hand comb at regular intervals, or by an oscillating comb suitably operated in the way made by Messrs. John Hetherington and Sons, as illustrated in Fig. [48] (page 60). In this case the dirt roller A is driven by a side shaft by means of the worms B and D, the latter gearing into the wheel E, which is keyed on the dirt roller spindle. A cam F fixed on the first working roller gives a reciprocating motion to the rail G by which the comb H is operated, the roller J being thus stripped. An iron tray I is fixed, as shown, into which the strippings fall.

Fig. 46.J.N.

Fig. 47.

(112) After passing the dirt roller the cotton is treated by the teeth on a smaller roller, K, known as a “worker” roller, which revolves in the direction of the arrow. Each worker has a smaller roller, L, placed in contact with it and called a “clearer.” The teeth on the worker have an inclination which is the reverse of those on the cylinder, and any cotton which is not fixed in the wire surface of the latter, or which is flung up by the centrifugal action of the cylinder, is seized by the worker teeth and removed. The worker revolves at a slower speed than the cylinder, its surface velocity being about 20 feet per minute, and varies in diameter from 5 to 6 inches. The clearer, which is 3 or 3¹⁄₂ inches in diameter, has its teeth set in the same direction as its motion, and its surface speed being about 400 feet per minute, it takes the cotton from the worker and again transfers it to the cylinder. As the surface velocity of the latter is higher than that of the clearer, the cotton is struck by its teeth and is drawn off the clearer and carried forward to the next pair of rollers. It should be pointed out that, although the cotton on the cylinder passes the clearer before it reaches the worker, the inclination of the clearer teeth is such that they cannot take up the fibres; while, on the other hand, the worker teeth are so set that, as previously pointed out, they take up the fibres from the cylinder. Again, the different velocities off the workers, clearers and cylinders cause a series of condensations and attenuations of the fleece to occur. The short fibres and “nep” are laid hold of, and are either sufficiently loosened to be thrown off as “fly,” or are embedded in the teeth of the workers and clearers, which, in consequence, require periodical stripping, this being usually effected manually. The setting of the rollers must be such that they do not approach the cylinder too closely, but simply deal with the fibres thrown up by the revolution of the cylinder. The lighter the carding, provided cleanliness is achieved, the better for the cotton, as with too heavy carding considerable damage is done to the material.

Fig. 45.J.N.

Fig. 48.J.N.

Fig. 49.J.N.

(113) The rollers and clearers are fitted with spindles, projecting beyond the cylinder and framing, and sustained by suitable bearings. On the projecting ends of both worker and clearer rollers, pulleys, with grooved peripheries, are fixed, over which an endless belt or rope is passed, deriving its motion from a pulley on the cylinder shaft. The worker driving pulleys are on one side of the machine, and those of the clearers on the other. The setting of the rollers is important, and it is necessary to make special provision for it. Fixed on the framework of the machine, forming the base S, Fig. [46], is a semi-circular frame, which is known as the “bend.” On this are fitted a number of brackets, the centre lines of which are radial to the cylinder centre, each forming a bearing for one end of the roller spindle. Mr. John Mason employs a special form, which is produced by planing the soles or feet of two of the frames, bolting them together and turning them on the edge. They are reduced to the required diameter to permit of the necessary setting, and when separated form half a circle. Each of these is bolted to the upper edge of the frame, S, which is planed to receive them, and thus a firm and accurate surface is provided for the roller brackets. The latter are constructed so that one portion of them can be set radially, or the whole bracket may be moved, if desired. Semicircular ribs are formed on the side of the bend, through which setting screws, locked on each side of the rib by nuts, pass. In this way the necessary setting can be easily obtained. As the machine is worked the wire points wear, and, when they are sharpened, the relative distance of the centres of the cylinder and rollers is not disturbed. In other words, the space between the points of the teeth on the rollers and those on the cylinder remains unaltered. It is absolutely essential that a definite distance shall be preserved, and means of setting the rollers and clearers readily are imperative. This subject is treated at greater length at a later stage, when the revolving flat-card is described. A bracket made by Messrs. Lord Bros. is shown in Fig. [49], and it will be seen that ample provision is made for both lateral and radial adjustment.

(114) The whole of the worker and clearer rollers are covered by a case, as are also the doffer and licker-in. The emission of fly into the room is thus prevented, and its production materially diminished by the reduction of the disturbance of the air set up by the rapid rotation of the cylinder. The roller and clearer machine is often made with two cylinders, being then known as a “double” card. The cotton, after passing all the rollers placed above one cylinder, is transferred to the second by means of a small drum, similar in construction to a doffer, and known as a “tummer.” The second cylinder bearings are fastened to the framing of the machine, which is made continuous, thus giving great solidity and strength. Double carding is undoubtedly effective in producing a good sliver, and is used in some cases where yarns of a good quality and as fine as 60’s are spun. There has been, and still is, a controversy going on as to the respective merits of the various systems of carding, about which a good deal could be said. In the meantime it is sufficient to note that many spinners continue to put down roller cards in preference to some of the newer types.

(115) At the present time the “revolving flat” machine is the favourite one, and is being widely adopted. The peculiarity of its construction consists in the employment of a number of T shaped bars or “flats” extending across the top of the cylinder, and sustained at each end by the bend, or a plate attached to it. They are coupled by an endless pitched link chain, by means of which they are slowly traversed at a rate of about an inch per minute, in the same direction as the revolution of the cylinder. Referring now more particularly to Fig. [44] it will be seen that during the passage of the cotton from the licker-in to the doffer it is carried below the flats N, each of which has its underside covered with wire clothing. The chain passes round carrier pulleys, one of which is arranged to drive it, being itself driven at a regular speed in the manner shown. Each flat is thus carried over a certain portion of the circumference of the cylinder, and is then turned with its wire face upward. When this happens, an oscillating comb P strips the teeth, and they are then brushed out by the brush Q, usually formed with spirally arranged bristles, and sometimes made of wire. The flats vary in number from 89 to 110, of which there are from 40 to 50 always working. As they are specially constructed, it will be as well to describe the method of doing so at length.

(116) The flats are made of a T section for the greater part of their length, but have flat surfaces formed at each end, as shown in Fig. [51]. On these surfaces they travel, and are sustained in their course by the bend. The width of each flat is usually from 1¹⁄₈in. to 1³⁄₈in.—the narrower ones being generally preferred—and the length varies with the width of the cylinder. The underside of each flat is made quite level, in order to afford a surface from which the various mechanical operations can be conducted. As the wire clothing is fastened to this face it is obvious that, by making it the base of all subsequent treatment of the flat, a decided advantage is obtained. The first operation is that of milling two surfaces at the upper side of each end of the flat, at the same time trueing up the faces of the ears to which the chain is attached. A double-ended machine is used, fitted at each end with an instantaneous grip chuck, at the bottom of which is a steel face on to which the ends of the flat are placed, the flat having been previously stretched and straightened. The flat is then cramped down, and the cutter brought into operation. The flat is placed on the faces thus formed in the next machine, which is constructed with chucks at the end of two long radius arms. A cross spindle has a worm fitted on it, which gears with a segment at the end of the arms, and by revolving which the flat is brought under the cutters, and has a hollow cut into it of the desired radius. The flat is then chucked edge up and milled by a cutter on its upper side at the ends, so as to provide the necessary clearance for the chain. The next operation is to cut out, by means of a similar machine to the one with the long radius arms, the under surface of the flat end, which had been treated by that machine, so as to leave two surfaces on which the flat travels, the radius arms in this case being shorter. These surfaces have two objects—to lessen the friction when the flat is travelling, and to allow of the flat having the necessary heel given to it. The flat is then cramped down on the surface thus formed, and the snugs are drilled by a double-ended machine fitted with an automatic motion for withdrawing the drill. By the same machine the hole is tapped, the tap reversing when it has gone the requisite depth. After drilling the flat along the edges in order to enable the clothing to be fastened, it is complete so far as its treatment by machines is concerned.

(117) There are one or two things to notice in respect to the operations just described. The first is, that all the faces are formed from that on which the wire clothing is subsequently placed, and that consequently the flat when traversing is provided with working surfaces which ensure it being parallel to the cylinder all across, provided the bends are correctly set. This is, as will be seen, an important point. Again, the whole of the surfaces to which the chains are attached are true with the flat ends, so that there is no tendency to pull the flat askew. Having thus constructed, by the means indicated, the flat as perfect as is possible by machine, it is necessary to put the “heel” in, and also to correct any twist which may have arisen by the spring of the flat whilst being milled. There are two methods of testing this point, one mechanical and the other electrical. As will have been noticed from the description of the method of milling the flats, two parallel surfaces are formed at the upper and lower side of each end of the flat. It will be evident that, if the flat is placed upon either of these surfaces and tested by a suitable apparatus, the other surface should be as nearly as possible parallel with the first. In order to see that this is so, the flat is placed face downwards on two steel faces perfectly parallel with each other. At each end of the table carrying these faces is an indicating apparatus consisting of a graduated scale and two pairs of compound levers, so arranged that a slight inaccuracy is multiplied to a large extent. If, therefore, the flat is laid on the blocks and the points of the levers are allowed to fall on the four surfaces left after the flat is milled by the long and short radius machines, the setter can see at a glance if the surfaces are accurately formed. In practice, the two ridges or surfaces at the front of the flat—that is, the edge nearest to the doffer end of the card—are reduced somewhat by hand, thus throwing up the back edge. This is what is known as giving the “heel” to the flat, and its object is to leave a slight space between the wire points of the flats and cylinder at the back of the flat, while at the front these are as close as possible together without touching. The object of this is to prevent a rolling up of the strippings and cotton fibre, which has been found to exist where the wire at the back or “toe” of the flat nearly approached that of the cylinder. The heel having been given the flat is then tested by the apparatus described, but instead of all the fingers corresponding, this only occurs with the two which are in contact with the same surfaces on each edge of the flat. One pair registers the variation caused by the heel and should correspond, while the other pair registers the position of the untouched surface and must also correspond. This device is the one most commonly used, and gives very accurate results. Messrs. Howard and Bullough adopt an electrical test which is also said to give good results. Similar devices are used in some cases to set the bends accurately with the cylinders; in others a simple scriber or pointer being used and set down, so that a small slip of steel can be easily moved across the bend under its point. As the latter is carried in a bracket fixed to the cylinder the bend can easily be tested all round. Messrs. Howard and Bullough use an electrical scriber, contact with which rings a bell, and thus indicates the point requiring adjustment. The use of the graduated indicators as shown in Fig. [60] enables this to be easily made, and delicacy of adjustment attained.

Fig. 44.J.N.

(118) As the function of the flats is to remove by means of the wires attached to them the short fibre and nep, the more accurately the distance between the wire clothing on them and the cylinder is preserved, the better will be the effect produced. In order to attain this object it is necessary that the flats should be specially constructed and carried. A reference to Fig. [51] will show the construction of the flat, which is so finished (as was explained in paragraph 116) that the faces upon which it travels are parallel with the face upon which the wire is fixed. Thus, if the flat is borne upon a surface which is concentric with the surface of the cylinder, but so far from the centre of the latter as to compensate for the length of the wire on both, and provided that the two wire surfaces are accurately and evenly ground, it will be clear that over the whole of the surface there will be the same distance between the points of the wires. This is the condition which is absolutely the best for carding, but its constant maintenance is the problem. The flat course may be either formed on, or attached to, the frame O, and in either case is technically termed the “bend.” This phrase is often very indifferently used, and is sometimes applied to the framing O when the latter is acting as a support for the flats, and sometimes to the surface attached to or borne by it for the same purpose. It ought, however, to be insisted on, for the sake of clearness and definiteness, that the phrase “bend” should only be applied to that portion of the mechanism upon which the flats actually travel. If it be assumed that a machine is in condition for starting for the first time, that the surface of the flat end upon which it travels is set back from the flat wire surface ¹⁄₂ inch, and that the wire projects ¹⁄₂ inch beyond the cylinder surface, there is a necessity for a circle with a radius of 26 inches. It is, of course, perfectly easy to form a track on the edge of the frame O, which should be accurately machined so as to be quite concentric and of the radius required, in which case the required distance between the two wire surfaces could be perfectly established. But, during the operation of the machine, the wire points become blunted and no longer deal with the cotton as efficiently as they ought. This necessitates their re-sharpening by grinding, which involves a reduction of the size of the circle described by the points of the cylinder wire, and an enlargement of that described by the covering of the flats. As has been pointed out, it is better that the two wire surfaces should approach one another as closely as possible without touching, the most effective results being obtained in this way, and it therefore becomes necessary to find some method of lowering the flats in order to re-establish these conditions. This is precisely the difficulty which has to be overcome. It is perfectly clear that any flat course formed on the frame O cannot be so adjusted, and it is essential that some other adjustable surface sustained by O shall be found. If for a minute or two the work to be done is considered it will be seen that there is a very difficult problem to solve. If a circle is struck 51 inches in diameter, and at the same time a second circle 52 inches in diameter is described, from the same centre, some idea can be obtained of the actual conditions of the case. Supposing that the circle 51 inches diameter is reduced to 50¹⁄₄ inches (this representing the extreme variation in size arising from grinding), it will be at once observed that the dropping of the 52 inch circle in a radial line will be followed by the destruction of its concentricity with the other. In the case thus supposed the smaller circle represents the surface of the wire on the cylinder, while the larger one represents that of the ring upon which the end of the flats traverse. Now, while the former is reduced with ease by grinding, the latter is not so easily reduced, and the action of moving it nearer the centre, without its reduction, simply means that its centre is moved to the same extent, while the centre of the ground surface remains constant. In other words, the concentricity of the two circles is destroyed. As the concentricity of the flat course with the cylinder is absolutely essential, in order to get that close approach over the whole of the wire surfaces which has been shown to be necessary, it follows that its destruction implies ineffective and bad carding.

Fig. 50.

(119) The arc occupied by the flats in their traverse varies from 120 to 150 degrees, speaking roughly, so that in some way or other a flat course of that length, capable of adjustment, requires to be provided. By far the most common method of providing this is to fasten to the side of the machine at the upper edge of the frame O a flat plate, shown in Fig. [50], with its upper edge forming a segment of the circle required. This arrangement is the invention of the late Mr. Evan Leigh, and has been widely adopted. The shape of this plate, so far as its depth is concerned, is so arranged that it can be sprung or compressed into a smaller circle with the minimum amount of difficulty and strain. This is what is known as a “flexible” bend, and is in wider use than any other form. It is attached to the frame side by bolts, slots being formed in the bend casting at each end through which the bolts pass. It will be seen that the slots allow of a considerable range of movement in the bend, which is made use of in setting it after the wire has been ground. The setting is effected by springing the bend by means of screws, until a circle is formed equal to that required to enable the wire surface of the flats to be concentric with the wire surface of the cylinder. As a matter of fact, the setting is done by the carder by sound and by the use of a gauge, the combination of which permits him to ascertain fairly accurately that the flats are in a good working position. When the bend is set, it is locked against the frame by the bolts, and stops, which are placed midway between the points of support, are brought up to the under edge of the bend. The object of these is to uphold the bend, so as to avoid deflection from the weight of the flats. As the cylinder, which weighs 9 or 10 cwts., revolves always in one direction at a steady rate of 140 to 170 revolutions per minute, and as the pull of the driving strap is usually towards the front, it will be perceived that a tendency, at least, will always exist towards wear in the brasses at their front side. Thus it is possible that in addition to the necessity for providing for the lessened circle, it may be also requisite to take into account the movement of the centre in a horizontal direction. The latter difficulty, however, has been to a large extent overcome by the elongation of the bearings, which are now much longer in proportion to the diameter than was the case formerly. The special construction of the bearings in order to resist the action of wear or to afford means of setting will be treated at a later stage in this chapter.

(120) It has been the ordinary practice to place the flexible bend outside the framing, but it is becoming the practice to decrease the width of the cylinder, and consequently the length of the flat. The cylinder is now ordinarily made 37in. wide when fed from 40in. laps, the lap being narrowed as it approaches the feed roller by specially placed and designed guides. By diminishing the length of the flat, the tendency to deflection is also lessened, and, in addition to this, an improvement occurs in the selvedge of the sliver. It will be seen that in diminishing the width of the lap 3 inches, it is only possible to do so by squeezing in its edges or folding them over somewhat. Thus any thin place on the edge of the lap is thickened, and the sliver when produced has a better selvedge. This advantage is partially derived by the means mentioned, but there is a further cause of ragged selvedges, to which a good deal of attention has been given. Usually between the edge of the cylinder and the bend a space has been left, through which, when the cylinder is revolving, a current of air is induced. As the cotton is held in the wire clothing, which comes right up to the edge of the cylinder, the suction thus caused draws it out and causes ragged places. Messrs. Ashworth Brothers remedied this defect by the employment of a circular shield about the height of the cylinder wire, which is fixed to and revolves with the cylinder. This gap is now entirely closed by all makers.

Figs. 51 and 52.

(121) Messrs. John Hetherington and Sons adopt the plan shown in Figs. 51 and 52, which are cross sections of the cylinder, bends, and flats. Fig. [51] represents the old method of construction. The flat T is sustained by the flexible bend Z, which is controlled by the setting screws W, and is attached to the framing Y by the bolt shown. The cylinder V in this case is 40in. wide, and between it and the fixed bend a space is left, which is filled up by the introduction of the wood packing X. The latter is fastened to the fixed bend Y by screws as shown. The new plan is shown in Fig. [51]. In this case the flexible bend Z is fastened on the inside of the framing Y, the setting screw W being placed as shown. It will be seen that the edge of the cylinder V comes close up to the bend Z, and no induced air current is possible. The cylinder is reduced to 37in. wide as previously mentioned. The same firm adopt a very good method of dealing with the flexible bend, which is shown in Figs. [53] and [54] in transverse section and side elevation respectively. On the cylinder shaft a segmental rack V is fixed, which is driven by means of worm gearing, and the bands W U from the pulley X placed on the shaft. This also drives a spindle Z, borne in frames attached to the cylinder, on each end of which is a milling cutter. The cutters are kept in contact with the flexible bend Y, which is made a little larger than is necessary, and is bolted in its place after being accurately set. It is weighted with suspended weights R T, together equal to the weight of the flats when resting upon the bends, and attached to the bends at points midway between those at which they are set. In this way the actual conditions of working are established as nearly as possible before the mechanism is started. On commencing operations the milling cutters are at one end of the bend, and the cylinder is slowly revolved so as to traverse them over its surface. In this way it is accurately shaped to suit the conditions of the case, and is as true as a fixed bend could be made. Of course, as soon as the bend requires to be reset it is necessary to adopt the ordinary plan, but the treatment described undoubtedly facilitates subsequent setting.

Figs. 53 and 54.J.N.

(122) The plan adopted by Messrs. Platt Bros. and Co. Limited is shown in Figs. [55] and [56], the former being the new, and the latter the old, method. A perspective view of this machine fitted with the new bend is given in Fig. [57]. Dealing with Fig. [56] first, the cylinder A is separated from the framing B by the distance shown, this being filled up by the wood packing G. The flexible bend C is fastened to the framing on the outside, and is set by the screws shown. The cylinder in this case is 40 inches wide, and it will be noticed that the arms of the cylinder are level with its edge. In Fig. [55] the cylinder A is recessed so that it projects beyond the arms sufficiently to permit the bend B to come within the recess. The flexible bend C is attached in the manner shown to B, and is fulcrumed on the pin in its centre. The setting is obtained by means of the screws, as in the previous case. The clothing on the flat is secured at the ends by the clip or plate F, shown separately in side view and plan, and a thin plate E is fastened to the cylinder by which means the ingress of air is quite prevented. There is also a reduction in the widths of the cylinder and machine, in the latter case about 8 inches, so that a machine fed from a lap 45 inches wide occupies only the same space as a machine made on the old principle with a 40 inch lap.

Fig. 57.

(123) Before leaving this point there is one thing to be noticed which is important. A reference to either Fig. [52] or [56] will show that the chain is attached at the end of the flat immediately over the bend, whereas in Figs. [51] and [55] it is further from it. The former method is best, as being less likely to deflect the flat, and is being adapted to the new construction by both the firms named.

(124) The construction of machines with flexible bends, in spite of many objections which are continually being alleged, continues to be large. It is held by some spinners and machinists that the necessity for adjusting the flexible bend manually from three points is faulty, and that it is better to provide mechanism whereby the setting can be made by positive means and from one point. Several patented arrangements with this view have been made, and illustrations of most of them are given. In most cases a flexible bend—somewhat differently constructed—is used, although it does not always have that name given to it.

Figs. 55 and 56.J.N.

(125) In Figs. [58] and [59] the arrangement used by Messrs. Dobson and Barlow—to which the name “Simplex” is given—is illustrated. Fig. [59] is a side elevation of that portion of the machine where the bend is applied. Fixed to the framing Q of the machine are four brackets P, O, M, L, the last three of which are specially curved on their upper edge, while P is shaped to a curve on its inner surface. Fixed in the metal strip K—which is practically the flexible bend—are four pins, each bearing an anti-friction runner, which are kept in contact with the edges of O, M, and L, and with the inner surface of the bracket P respectively. Attached to K, at the opposite end to P, is the crank S, oscillating freely upon a pin fastened in the frame Q. At the end of the bend K, where it is controlled by the bracket P, and, on its inner edge, a toothed rack is formed, with which a small spur pinion engages. The pinion is fixed on the axis of a worm wheel R, rotating on a pin fastened in the framing Q. With the wheel a worm R¹ gears, and this can be rotated by a handle to any desired extent. When the bend K is moved by means of the rack in the direction of the arrow, it is put into tension, and the anti-friction bowls are drawn down on to the surfaces of the various branches. A glance at the detached sectional view given will show that the various brackets overlap the bend K, which slides between them and the frame Q. The position of the bend is arranged so that between it and the edge of the cylinder there is no open space left.

(126) Having thus described the actual mechanism a few words can be said about Fig. [58], which is a diagrammatic representation of it. The circle A B is that formed by the edge of the bend or plate K when it is at its highest position—that is, when the wire is unworn. The circle D E is that described by the edge of K when it has been drawn down to allow the flats to come nearer the cylinder. The small black dots represent the pins fixed in the bend K. When the latter is moved by the action of the rack and pinion, the end of the crank S follows the path of the circle described by it, moving from B to E during the time the entire depression of the plate is made. The anti-friction bowls in the same period travel in the paths shown, and it will be noticed that each of the curves is differently shaped. If the inner circle F G be supposed to represent that occupied by the edge of K after the crank end has travelled from B to G—a half circle—the curves L M O P would, if prolonged, be of the shape shown. Having obtained them in the manner thus described on paper, they are actually reproduced on the brackets by a milling machine fitted with a copying arrangement. By forming an indicator scale on the worm wheel R the amount of movement of the bend K can be regulated as desired to any degree of accuracy. The proportions of the worm, worm wheel, pinion, and rack, are so arranged that the advance of the wheel ¹⁄₅₀th inch will raise or lower the bend K ¹⁄₂₀₀₀th inch. This method is very simple and effective.

Fig. 60.

Figs. 58 and 59.J.N.

(127) The arrangement adopted by Messrs. Howard and Bullough has the central idea of the employment of inclined surfaces, by withdrawing one of which the other can be lowered. It is shown in front elevation in Fig. [60] and in section in Fig. [61]. The fixed bend has formed on one side of it a broad flange, which is turned to a true circle on its upper edge. Upon this a segment of a ring A is placed, which can be slid in or out by means of the screw B and lock nuts. The back nut is riveted to the index disc E, which is divided into 36 spaces, the front lock nut securing the arrangement after setting. In front of the dial plate E an indicator finger D is fitted, which points out any alteration of the circular dial plate E. Upon the upper surface of the ring A a second ring C of a smaller section is placed. C is accurately turned on its inner side to correspond with the inclination of the upper surface of A, and on its outer edge is horizontal, so as to form a course for the end of the flat. The ring C is pressed down upon A by the weight of the chain of flats as they pass over it. The action of this mechanism is easily understood. By withdrawing the segmental ring A, by means of the screw B, the flats are lowered, the degree of their depression being sufficient to preserve the necessary distance between their wire teeth G and those F upon the cylinder H. The adjustment can be made in either direction, and the graduation of the dial E enables it to be finely made. In this case also, as shown in Fig. [55], the gap at the end of the cylinder is closed by bringing the flange of the fixed bend close to the edge of the cylinder.

Fig. 61.J.N.

Fig. 62.J.N.

(128) In Figs. [62] and [63] a plan invented by Mr. Thomas Knowles, of Bolton, and made by Messrs. John Tatham Limited is illustrated. This consists of the employment of a wedge-shaped segmental ring, which rests upon the upper edge of the fixed bend, and can be drawn along it by means of the screw shown. The ring is pierced by a number of holes of decreasing diameter, and a small slit is made through the web left between the lower part of the hole and the inner surface of the ring. The latter is thus rendered easily flexible, and the mere weight of the flats is sufficient to make it accommodate itself to its supporting surface. The ring is shaped so that the inner edge forms part of a spiral curve, shown diagrammatically in Fig. [63], and with its outer edge levelled so as to bear the flat. In like manner the edge of the fixed bend is shaped to the spiral curve, both of these being obtained by the use of a circular milling machine fitted with the necessary shaping mechanism. The spiral curve to which the two surfaces are formed would, if continued far enough, terminate in the centre of the cylinder, so that if it were possible to traverse the ring far enough it would actually cross that point. The action of setting this mechanism is simple. The ring is drawn downwards by the screw, and its outer edge thus moves nearer the centre of the cylinder to an extent corresponding with that of its traverse. Any adjustment desired can thus be given in either direction.

Fig. 63.J.N.

Fig. 64.J.N.

(129) The machine made by Messrs. Ashworth Bros., of which a perspective view was given in Fig. [44], is based upon an entirely different principle. Before passing on to describe it, it is only fair to say that to this firm belongs in great measure the great advance which has been made in the construction of this form of machine. They recognised the importance of accurate mechanical construction, with the result that they produced a machine which could be run at much higher velocities than had hitherto been thought possible. Referring now to Fig. [64], on the top of the fixed bend B, a number (about 15) of thin steel bands E are placed, being held at one end by the stud G and kept in tension by the screw C, thus being firmly drawn into position. The bands are of various thicknesses, from ¹⁄₃₀th to ¹⁄₁₀₀th inch. The end of the flat traverses on the top band F, and any of them can be removed and replaced by a thinner one. Thus the concentricity of the flat course is preserved, provided that the amount of wear to be taken up corresponds with the difference between the thickness of the band taken out and that replacing it. It may happen that the amount of wear to be provided for is not enough to justify the removal of the band, which, on account of the necessary labour involved, takes some little time. In order to afford a ready means of making the correction, and at the same time avoiding the replacement of the bands, the makers have adopted the bold but ingenious plan of forming the cylinder bearing so as to be adjustable vertically. Referring now to Fig. [64] it will be noticed that the engine bend and the pedestal are cast in one piece, bolted on to the lower frame. The pedestal cap is fastened by means of set screws, but the bottom brass can be lifted by means of the vertical screw shown in dotted lines. This screw is fitted into the pedestal, which is tapped to correspond, and has at its lower end a ring which is divided into 100 parts on its circumference. An indicator finger is fitted so that the ring can set to any of the divisions as desired, and when so set the screw can be locked by a lock nut. By proportioning the pitch of the thread it is clear that any desired lift can be obtained. The pitch adopted being ¹⁄₁₀th of an inch, a revolution of the screw one division on the ring would mean a vertical movement equal to ¹⁄₁₀₀₀th of an inch. Now it is quite true that in a sense any vertical movement of the cylinder destroys the concentricity of the flats, but this, after all, is a relative matter. If reference is made to a drawing showing the arc occupied by the flats in various positions, it will be seen that with a total fall of ³⁄₈ths of an inch the difference between the ends and centres of the arcs described does not amount to a great deal. Therefore if the cylinder was raised by the screw about ¹⁄₈th inch it would not amount to an inaccuracy of any magnitude. But as the thickest band is only ¹⁄₃₀th of an inch thick it would be most likely that instead of lifting the cylinder anything like ¹⁄₈th inch a band would be taken out and the wear thus compensated for. The raising of the cylinder ¹⁄₃₀th of an inch would practically mean that the setting of the flats would remain unaltered.