the threads or yarns contained in the strands were wound by hand into a ball from a creel containing the requisite quantity of yarns, but this system, owing to the irregular draft of the threads hy the hand, and the twist imparted by balling, only yielded an indifferent quality of twine. Several machines have been invented to obviate the defects of hand-winding, with more or less success. Fig. 1187 is an illustration of one of the most recent and perfect of doubling-winding-machines, as machines for winding several threads together upon one bobbin are called. It is described by the inventor, T. Unsworth, Manchester, as a direct-acting, dmw-bolt, positive stop-motion, doubling-winding-frame. With slight modifications, chiefly in dimension, it can be adapted for working any description of fibre—silk, cotton, wool, flax, jute, or hemp, and in any degree of fineness. It can be constructed to wind any number of threads upon one bobbin : it is usually made for 15-20. A shaft a (Fig. 1188) bearing upon the ends of the frame extends throughout its length, and is fitted with friction-drums b, and, projecting beyond the frame, also carries the driving-pulleys. Each drum has a similar one c adjusted to be driven by the friction of the one flrst mentioned. The second drum is in contact with and drives the bobbins d. Over the bobbio, is placed a porcelain pressure-bowl e, which works in contact with tbe yarn upon the bobbin. Beneath the second drum, and hollowed to fit its periphery, is a brake, into which, by the action of the stop-needle, the drum is made to fall. This drum c is fitted upon a lever f, the opposite end of which projects towards the front of the machine, extending to and resting upon the draw-bolt g— a bar covered with a spiral spring to hold it in position, and which sustains the bolt in contact with the driver drum. The reverse ex tremity of the draw-bolt has a cross piece h attached, thus forming a representation of the letter I laid horizontally with the cross-piece outwards. In the oblong frames affixed near the front of the machine, each of which is horizontally divided by a bar through the middle, are inserted the direct-action stop needles 1, which constitute the chief feature of the machine. The needles are composed of two parts, looped together (Fig. 1187). On the upper part, is a curl through which the threads pass ; the lower part, pendant by the loop from the upper, drope its extremity on tho inner side ef the cross-piece of the T-shaped draw-bolt h, and the outer side of a rocking-bar k extending the length of the machine, which is actuated by eccentrics.
The cope or bobbins having been placed in the creel, the threads from each are conducted upwards through the first eyelets, thence over a glass rod, through the curls of the stop-needles, and around the revolving porcelain bowl or curl 1 of the yarn-guide, whence they pass upon the bobbin. The action of the machine is as fellows :—The needle, by means of the thread, is suspended at such a height as to be clear of the rocking-bar ; but when the thread sustaining it breaks, it instantly falls, ite lower extlemity dropping in front of the rocking-bar, which strikes it against the draw bolt, pushing the latter forward so ne to release the end of the lever supporting the second friction drum, whieh instantly drops into the half-round break, and at once stops the revolution of the bobbin without friction.
The chief objects sought in doubling-winding are uniformity in the lengths of the threads laid together, equality of tension, and freedom from " single" caused by dropped threads. All these
faults are discovered in subsequent processes, showing themselves in " cork-screws " and other defects, which greatly deteriorate the quality. The lengths may vary through irregularity in wiuding, caused by a varying amount of friction upon the different bobbins, or an uneven deposit of the yarn upon the barrel of the bobbin. But by this machine, both these faults are prevented : the first by the suspension of the stop-needle upon the thread, which hkes up auy momentary slack ; and the second by the threads being passed in a tape-like band over the revolving bowl upon the traverse-rod, which deposits it evenly upon the bobbin, which the pressure-bowl further helps to render firm and level. " Single " is prevented as previously described. The pressure-bowls are merle of 3-20 lb. weight, according to the nature of the fibre upon which the machine is to be employed.
Twisting.—The bobbins containing the threads necessary to form a strand are conveyed to the twisting-machine, au improved form of which is shown in Figs. 1189,1190. The twisting-spindle a, which receives the bobbin from the last-mentioued frame, occupies the ordinary position ; but its flier, which has two or four legs as play be required, is inverted, and brought down upon the spindle to near the bolster-rail b, resting upon a u3etallic washer, which carries one of cloth or flannel, by means of which an easy drag of the bobbin is obtained. The inversion and change of position of the flier give increased steadiness to the spindle, especially when running at high velocities, and thus, at less expense in wear and tear, a greater production and superior quality of yarn are obtained. The attainment of high speeds in this machine is greatly facilitated by the bolster-rail not being a traverse-rail as well ; all the weight of the yarn, bobbin and flier is concentrated upon the bearing, while the spindle is reduced to the size of the bobbin. The unwinding traverse is nbtained by pluming the yarn round one leg of the flier.
After leaving the dobbin, the yarn passes over a carrier-mil c, and upon the twist-rollere inter mediate between the delivery- and the taking-up-rollers. The twist-: oilers d d' are conical grooved pulleys placed upon parallel horizontal shafts, one function of the first row being to draw the yarn from the bobbins, whilst the revolving spindle puts in the twist. The yarn passes upon one of the smallest grooves of the cone d, and over a larger ono in the cone d', which stretches the strand aud lays the yarn well together before it passes upon the taking-up-bobbin e. The last-mentioned bobbin can be made of any required dimension, as, its only function being to take up the yarn when twisted, weight is no objection. In the sectional view, the twist-rollers are sl,own with an alter native arrangement.
This machine, one of whose novelties lies in its being an " upward twister," has a great pro ductive power. One of 200 spindles will turn off 2400 lb. a week of 3-fold 8's cotton, 9 turns an in., which is A. more than can be obtained from ordinary machines. One girl can superintend the machine, creeling and doffing without assistance. Owing to the employment of large winding and taking-up-bobbins, a greater length of yarn can be produced without a knot ; and through the stretching on the cones, the twisted strand is made round, firm, and full. The cost of warp-winding is also saved, as the machine winds the yarn upon large warping-bobbins during the operation of twisting ; less space and power are also needed.