Hosiery Manufacture

by M.A. William Davis

Dividing the Loops.—The sinking of the loops in the normal frame takes place on every second needle only, and the yarn thus supplied is distributed equally over all the needles in the process of dividing. In this what are termed the dividing sinkers are brought forward in a body and spread the yarn equally over all the needles. In the operation of sinking and dividing the part of the sinker most in use is the throat, marked A, and this is the point where wear most rapidly occurs due to the friction of the yarn. Wearing is accelerated in the case of stiff yarns being worked on the machine and sinkers have to be specially tempered or hardened to give adequate service.

Pressing and Landing.—These two operations are performed in close succession and are illustrated in Fig. 31. At this stage the presser comes largely into the picture, and in itself is simply a piece of steel fixed in front of the bar in which the sinkers work. The needles tilt somewhat to the left and push their beards against the presser, so that the beards enter the grooves marked D in Fig. 29, and at almost the same instant the old loops pass on to the beards or are landed. Obviously the timing of the pressing and the landing of the loop is of the closest description; the spring is pressed into the groove and in an infinitesimal space of time the needle moves downwards and the old loop slips on to the pressed beard. Immediately this is completed the needle leaves the presser and the beard springs back to its former position once again. In pressing a great strain is thrown on the beards of the needles, and if the metal is soft or devoid of elasticity defective knitting at once results.

Knocking-over or Discharging.—This operation is shown in Fig. 32, and consists in drawing the new yarn through the old loop and throwing off the latter to take its place in the fabric. The new yarn is pulled through the former stitch and the main factor in discharging is the downward sweep of the sinker in relation to the position of the knocking-over bit DP. These are arranged in a kind of stationary comb and act as a rest to the loops whilst the needle is making its descent. Again, it is seen that correct drawing through of the loop is of the utmost importance for successful stitch formation, and knitting is impeded if stitches which should be thrown into the fabric remain on the needle stems undischarged.

It will be seen that the loop-forming process with the bearded needle as agent is carried through in a series of operations, all of which must be perfectly co-ordinated and timed in relation to each other. When it is essential to secure the highest results in regard to fabric texture, the bearded needle machine is chosen in preference to the ordinary form of latch needle machine. The method of using sinkers for loop formation induces greater uniformity of stitch as the thread is accurately served out to the needles, and kept under perfect control from start to finish of the operation. One great difference between this and latch needle knitting is that the course of loops is made as a whole, and after sinking they are divided, pressed, and discharged at the same time across the entire width.

Knitting on the Hand-frame.—Hand-knitted fabrics may have two meanings attached to them, they may be worked entirely by hand on the knitting pins where each stitch in the article is formed by hand. Again, hand goods may be worked on the hand-frame, the earliest form of knitting machine, where the actual operations of sinking, knocking-over, etc., are performed mechanically by a series of movements performed by the hands and feet. Fig. 34 gives a view of the functional parts of a hand-frame directly connected with the elementary operation of knitting. This is a side elevation showing a complete jack, sinker, etc. The action of stitch formation is identical whether made on the hand-frame or power machine, the sequence being sinking, dividing, pressing, landing, and discharging of the loops. In the Fig. 34 the various parts are marked as follows: N = needle, NB = needle bar, NL = needle lead, B = needle beard, P = presser, T = thread, TC = thread-carrier, S = sinker, FB = falling bar, J = jack, JW = hole for jack wire, SC = slurcock, V = spring; on the sinker S the following parts may be distinguished: 1 = small nose or neb, 2 = large nose, 3 = sinker throat, K = sinker belly.

Working of the Parts.—To form a course of loops the parts mentioned combine their action in the knitting operation, and some further explanation may be given of the manner in which this is executed on the hand-frame. The thread T proceeds from a bobbin at the side of the frame and passes through the eye of the thread-carrier TC, as shown by the dotted line. The thread-carrier has an alternate motion from left to right and from right to left and at the same time the slurcock has its side-to-side movement in the wake of the thread-carrier, being timed to run just a little behind. The action of the slurcock SC is to strike the tails of the jacks J and tilt them up so that the sinker drops on to the yarn which has just been placed over the stems of the needles and pushes the yarn a short distance between them. The part of the sinker acting at this stage is the small nose 1, whilst the fabric marked F and its stitches hang in the sinker throats 3. The sinkers are then drawn forward in a body by handle bars in which the sinker tails are placed, and this action pushes the sinker loops under the beards B of the needles N. When this is completed the presser marked P is drawn firmly down on to the beards of the needles and the sinker with a further movement to the right pushes the old loops so that they cover the beards. When the old stitches have been completely and securely landed in this fashion, the presser releases its hold on the beards or springs; the sinkers are drawn still further to the right and, with an upward sweep of their bellies marked K, the old loops are thrown over the needle ends and the new loops drawn through. The sinkers are then pulled well down in front of the machine to secure the loops in their throats 3, and with a push are again replaced on the stems of the needles previous to re-commencing all over again. The jack is fulcrummed at the point marked JW which is a hole through which a wire is passed, called the jack wire; the spring V is important in fixing the position of the jack when in its non-operative position and keeps all sinkers in line until the sidewise action of the slurcock releases them and causes the fall of the jacks. The slurcock SC is drawn from side to side by what is termed the slur wheel, which oscillates, and a separate cord on this wheel makes the thread-carrier perform a similar motion from side to side. The falling bar FB is rather important in that it determines the size of the loop sunk on the frame. Obviously when the jacks are released they are free to fall a certain distance, and this distance determines the length of loop sunk between the needles of the machine. The longer the loops, the lower are the jacks allowed to fall, whilst a higher adjustment of the falling bar FB produces a shorter loop. The needle N is shown to be fixed in the needle lead NL, which in turn is fixed in the needle bar NB. These are arranged along the bar with a given number clamped under a metal piece, and when a needle breaks this clamp is removed at that region only which obviates needles being uncovered for the whole width. Other points in the mechanism arrangement to note are that the needles are horizontal and fixed, whilst the sinkers are vertical and jacks horizontal. The presser is moveable and the fabric proceeds downwards, there being a winding roller to take up the fabric.

Figs. 34 and 35

The hand-frame is rapidly disappearing from our knitting establishments, although this is rather due to a decline of apprentices willing to learn the business than lack of work. Some firms of good standing in the trade still experience an insistent demand for real hand-frame goods, as they are unrivalled in point of quality and wearing properties. It is not strictly true that the hand-frame makes fabrics of so much better quality than the power machine, but owing to the higher cost of working on the hand-frame as compared with the power machine, it is futile to make inferior or low-grade materials by hand. Experts declare that no fabric is equal in textural excellence to that produced on the hand-frame. The old stocking-maker was a skilled craftsman, who in the course of years established a close sympathy between himself and the machine he was working; he could interpret its moods of facile operation. Certainly he learned how to humour the machine according to the nature of the material and in the great subtleties of "meeting the presser" and consequent knocking-over of the loops he acquired the skill of imparting to the article a "skin," which the connoisseur declares to be absent from the automatic machine-made product. The hand-frame worker was a skilled artist in the respect of shaping articles to the fit of the individual and his pride was that any person, however far removed from the normal, could be provided with a garment exactly suitable to his form.

The Power Frame.—It is outside the scope of this work to give in detail all the various knitting mechanisms, but it is important for the reader to have a clear idea of how the knitting process is conducted on several standard machines, for when these basic principles have been mastered they can be applied quickly to elucidate the method of operation of almost any variety of machine in the whole wide range of the hosiery machine builder. The hand-frame as invented by Lee held its own in the forefront of the industry for many decades and was undoubtedly a work of genius, for it was practically perfect from the start, as succeeding efforts at improvement produced little change in the hand-frame as such. Even after automatic machine knitting was introduced, the machine followed closely upon the hand-frame type, all the leading features such as sinkers, jacks and needles being placed exactly as in the hand machine, except that the motions were produced by a series of shafts, cams and belts.