SILK MANUFACTURE 



793 



D, D, are two horizontal iron shafts, which pervade the whole machine, and carry a 

 series of light moveable pulleys, called stars, c, c (figs. 1777, 1779), which serve to 

 drive the bobbins E, whose fixed pulleys rest upon their peripheries, and are therefore 

 turned simply by friction. 

 These bobbins are screwed *' 



by swivel-nuts, e, e, upon 

 spindles, as in the silk-engine. 

 Besides the small friction- 

 pulley, or boss, d, seen best in 

 Jig. 1779, by which they rest 

 upon the star-pulleys c, c, a 

 little ratchet-wheel, /, is at- 

 tached to the other end of each 

 bobbin. This is also shown 

 by itself at/, in fig. 1778. 



The spindles, with their 

 bobbins, revolve in two slot- 

 bearings, F, F, fig. 1779, 

 screwed to the bar-beam a, 

 which is supported by two 

 or three intermediate upright 

 frames, such as A'. The slot- 

 bearings F have also a second slot, in which the spindle with the bobbin is laid at rest, 

 out of contact of the star-wheel, while its broken thread is being mended. G is the 

 guide-bar (to which the cleaner slit-pieces, g, g, are attached), for making the thread 

 traverse to the right and the left, for its proper distribution over the surface of the 

 bobbin. The guide-bar of the doubling-machine is moved with a slower traverse 

 than in the engine ; otherwise, in consequence of the different obliquities of the paths, 

 the single threads would be readily broken, h, h, is a pair of smooth rods of iron or 

 brass, placed parallel to each of the two sides of the machine, and made fast to the 

 standards H, H, which are screwed to brackets projecting from the frames A, A'. Over 

 these rods the silk threads glide, in their passage to the guide-wires g, g, and the 

 bobbins E. 



i, i, is the lever-board upon each side of the machine, upon which the slight brass 

 bearings or fulcrums i, i, one for each bobbin in the creel, are made fast. This board 

 bears the balance-lever k, I, with the/aWers n, n, n, which act as dexterous fingers, and 

 stop the bobbin from winding-on the instant a thread may chance to break. The levers 

 Jc, I, swing upon a fine wire axis, which passes through their props i, i, their arms being 

 shaped rectangularly, as shown at k, k' (fig. 1779). The arm I being heavier than the 

 arm k, naturally rests upon the ridge-bar 

 m, of the lever-board i. n, n, n, are 

 three wires, resting at one of their ends 

 upon the axis of the fulcrum i, i, ard 

 having each of their other hooked ends .H 

 suspended by one of the silk threads, as 

 it passes over the front steel rod h, and 

 under h'. These faller-wires, or stop- 

 fingers, are guided truly in their up- 

 and-down motions with the thread, by a 

 cleaner-plat o, having a vertical slit in 

 its middle. Hence, whenever any thread 

 happens to break, in its way to a wind- 

 ing-on bobbin E, the wire n, which hung 

 by its eyelet end to that thread, as it 

 passed through between the steel rods in 

 the line of h, h j , falls upon the lighter 

 arm of the balance-lever k, I, weighs down thaterm k, consequently jerks up the arm I, 

 which pitches its tip or end into one of the three notches of the racket or catch-wheel 

 / (figs. 1778 and 1779), fixed to the end of the bobbin. Thus its motion is instan- 

 taneously arrested, till the girl has had leisure to mend the thread, whon she again 

 hangs up the faller-wire n, and restores the lever k, I, to its horizontal position. If, 

 meanwhile, she took occasion to remove the winding-bobbin out of the sunk slot-bearing, 

 where pulley d touches the star-wheel c, into the right-hand upper slot of repose, she 

 must now shift it into its slot of rotation. 



The motions are given to the doubling-machine in a very simple way. Upon the 

 end of the frame, represented in fig. 1775, the shafts bear two spur-wheels, 1 and 2, 

 which work into each other. To the wheel 1 is attached the bevel-wheel 3, driven by 



.1779 



