Fig. 192.J.N.
Fig. 193.J.N.
(374) In Fig. [192] a spindle known as the “Whitin Gravity” is illustrated, being made in this country by Mr. Wm. Ryder, of Bolton. The spindle B has fitted on to it the sleeve A, made shorter than usual. On A the warve is formed, as well as a conical shoulder on which the lower end of the bobbin fits tightly. The bolster C has the usual screwed shank, and passes upward into the sleeve. A noticeable feature of the Whitin is the employment of a loose sleeve in which the spindle fits, and which has an external diameter at the point D about 1⁄500 inch less than the internal diameter of the bolster at that point. The lower part of the sleeve is recessed so as to pass over a nipple G formed in the bolster, the size of the sleeve being such as to allow of its adjustment in any direction. On the top of the nipple G a small pad of cork F is placed, the object of which is to limit by its friction the movement of the sleeve and spindle, and also to absorb vibration. The bolster is recessed so as to form a cavity surrounding the tube D, in which the oil is placed, finding its way to the spindle by means of small holes bored in D. The spindle does not, therefore, as in the Rabbeth, revolve in oil, and any sediment which may be in the latter is allowed to settle in a cavity or recess at the foot H. The Whitin can be run without any difficulty at very high speeds. Another spindle in which this principle is used has been largely adopted, and is known as the “Ferguslie.” The inner sleeve in this case has freedom of oscillation, which is controlled by a barrel-shaped spring placed round the upper part of the bearing. It may be noted that the lower end of the inner sleeve is quite free, and that the entire control comes from the spring at the top. There are many other forms of this type of spindle, Messrs. Dobson and Barlow, for instance, employing a cork cushion in lieu of a spring. Mr. John Dodd, of Messrs. Platt Brothers and Co., Limited, has patented the spindle illustrated in Fig. [193], which the author is informed is running at a very high velocity, and giving very good results. The spindle A is carried in a tube or bolster D, formed with a rectangular nipple C at its lower end, in order to prevent its turning with the rotation of the former. The spindle A is formed, as shown, of a special shape, being strengthened above the top of the bolster, so as to be stiffened somewhat where the bobbin fits. The main arrangement of the bolster case, sleeve, etc., is similar to the Rabbeth, but the bolster case extends upwards a little above the bolster, and on the spindle a collar B is formed, by which the oil which works up above the top of D is thrown off so as to catch on the bolster case and run down again into the chamber which is formed at its lower end. The oil passes through holes in the tube, thus providing for an efficient lubrication, and the tube is so fitted into the case as to be a little less than its internal diameter. It is probable that in working D will be constantly surrounded with oil, which will form a pretty effective cushion. At any rate it is found that high velocities can be attained with this spindle, combined with complete steadiness. In Fig. [194] (see p. [249]), the “Bee” spindle, which is the invention of the late Mr. George Bernhardt, of Radcliffe, is illustrated. This gentleman gave a good deal of attention to this special class of spinning machines, and was the inventor of many useful appliances in connection therewith. The chief feature of the Bee spindle is the formation of the bearing in the shape of a long tube, which can be withdrawn from the bolster case and emptied of oil without disturbing the spindle. The tube is held in position by a bayonet catch, and can be withdrawn and replaced in a very short space of time. If desired, the tube can be arranged to rotate as it is acted on by the revolving spindle, but this is not essential. The use of a withdrawable tube is a very valuable feature in principle, and is worth favourable consideration. In passing it may be stated that the adoption of spindles with elastic bearings has led to a shortening of the driving sleeve, and a reduction of the height of the top bearing, as a comparison of Figs. [191] and [192] will show.
(375) The ring, the use of which gives its name to the system, is made of the form shown in the drawings, and varies in diameter from 1 inch to 5 or 6 inches, as required, 2 inches being a very common size. The diameter is, of course, determined by the counts being spun, the cop or spool produced being larger in proportion to the coarseness of the counts. A table of the ordinary sizes employed will be found at the end of this chapter. The important points in a ring are its perfect circularity, smoothness of surface, and hardness, three features which tax the energies of manufacturers to obtain at the prices paid for these articles, Formerly rings were produced out of iron of good quality, which was formed into a hoop and perfectly welded, but latterly steel has come largely into use, and it is the practice to obtain the blank without a joint. The rings are in some cases milled, and in others turned and bored to the required section, and are subsequently case-hardened. A large percentage of the soft rings fail in the case-hardening, and the production of a perfect article is only possible with a proportion of the blanks dealt with. In the great majority of cases the ring is made single—that is, with one bead only (Fig. [195])—but Messrs. Thomas Coulthard and Co., of Preston, produce a double ring, shown in Fig. [196], which can be reversed when needed. This firm provide a special holder for their ring, which is fitted on to the rail, and is also formed with a vertical arm or projection which knocks the fly off the traveller as the latter revolves. The fly is—as explained—the collection of loose fibres which are thrown off from the surface of the yarn in its passage to the spindle, and which if left adhering to the ring or traveller increases the drag and causes breakage. It may be repeated here that cleanliness is a most important feature, and requires constant attainment if spinning is to be conducted successfully. A special lubricant is provided for the ring and traveller, ordinary oils being useless.
(376) The travellers are, as previously mentioned, made of a C shape, but this is not invariable, and are of various weights to suit varying circumstances. There are two standards of weight used in manufacturing travellers in this country, one known as the Scotch and the other as the United States. The Scotch standard probably derived its name from the fact that it was originally, and still is, manufactured in Paisley, by Messrs. Eadie Brothers. The difference between the two lies in the size of the bow for fine numbers from 1/0 to 3/0—used in spinning 28’s counts yarn and finer. The smaller bow is used in the Scotch standard, and it enables a thicker steel to be used, giving greater strength to the traveller and preventing it being pulled off the ring so easily. Thus, in spinning 32’s, a number 2/0 to 3/0 Scotch standard can be used, whereas the number in United States standard would be 3/0 to 4/0. For fine yarns a light traveller is necessary, while for coarse counts or strong doubled yarn a proportionately heavier one is used. A good deal depends, however, on the quality of cotton used, good Sea Island, for instance, enabling yarn to be spun with a traveller three or four sizes heavier than that permissible with inferior cotton. The diameter of the ring used, the number of twists per inch, and the speed of the spindles are among the things which influence the choice of the traveller used. It may be said that, although definite rules are made as to the weight of traveller used for certain counts under fixed conditions, a careful overlooker can make a vast difference in the production by selecting the exact size of traveller best adapted to particular yarns.
Figs. 195 and 196.
(377) Having thus described the essential portions of a ring spinning machine, some of the difficulties and principles of the mechanism may be dealt with. It is quite certain that the full theoretical reasons for the successful accomplishment of this work are not now forthcoming, but an approximation to them is possible. The actual spinning process is merely a twisting together of the fibres of any material by the rapid revolution of a flyer or spindle while the fibre is being delivered at a definite rate. In this case the twist is put in by the rotation of the traveller, which, as shown, is actuated from the spindle. As it has never yet been accomplished to take off the yarn from the spindle at the same rate as it is being wound on, it is necessary that the twisted fibre should be collected on the spindle or on a bobbin super-imposed on it. In order to do this, as was shown in Chapter [X]., it is essential that the eye or guide through which it is delivered to the spindle should travel either faster or slower than any fixed imaginary point on the spindle. The latter is the invariable rule with the ring frame, and it will be seen that as the bobbin is revolving at a quicker rate than the flyer eye, or in this case the traveller, it will take up the yarn and gradually wind it on to itself. Of course, in the case of a mule this does not happen, the winding arrangement being there altogether different. The amount of “lead” which the bobbin has should correspond approximately to the number of inches of yarn delivered by the rollers. That is to say, if the yarn is receiving ten twists to the inch, the bobbin should take up approximately, during ten revolutions, one inch of yarn. Now it is quite clear that if the velocity of the bobbin varies, the speed at which the traveller is pulled round the ring will vary also, but that, owing to the resistance caused by its weight and frictional contact with the ring, it will always tend to lag behind the bobbin. A little examination will show that the weight of the traveller is really the determining, or, at any rate, the most important, element in the case. As has been explained, the rotation of the traveller is caused by the pull exercised on it by the yarn. Now the velocity at which ring spindles are revolved is very great, averaging in ordinary cases at least 8,000 per minute. It is quite clear that a traveller rotating at that speed will tend by centrifugal force to fly outwards, and thus cause its inner lip or edge to press against the inside of the ring. Although it is quite true that this contact is only a slight one it exists, and constitutes one of the elements in the case. But it is also evident that the greater the weight of the traveller the greater will be the force that is exerted against the inside of the ring. While the author does not wish to do more than express his own opinion in this matter, there seems to be substantial ground for belief that the tangential pull on the yarn between the traveller and the point at which it reaches the bobbin will to a great extent counterbalance the tendency to fly outwards. It therefore seems probable that the reasonable explanation of the drag of the traveller is to be found in the resistance set up by its weight rather than by its frictional contact with the ring. This is the principle upon which travellers are made, their weight being carefully graded in order to suit various counts of yarn and velocities of spindles. There is another feature in which the weight of the traveller is evidently of importance, and that is its relation to what is known as ballooning.