796 



SILK MANUFACTURE 



1782 



riggers upon the shafts of the upper and the under drums to be driven from the same 

 pulley upon the main shaft, the axis of the under drum is prolonged at L, i/, and 



supported at its end, directly from the floor, by 

 an upright bearing. Upon the shafts of the 

 tin cylinders there is also a fly-wheel, H, to 

 equalise the motion. Upon the other ends of 

 these shafts, namely, at the end of the spinning 

 mill, represented in Jig. 1782, the pinions 1, are 

 fixed, which drive the -wheels 3, by means of 

 the intermediate or carrier-wheel, 2, called also 

 the plate-wheel, from its being hollowed some- 

 what like a trencher. 1 is called the change 

 pinion, because it is changed for another of a 

 different size and different number of teeth, 

 when a change in the velocity of wheels 2 and 

 3 is to be made. To allow a greater or smaller 

 pinion to be applied at 1, the wheel 2 is 

 mounted upon a stud Jc, which is moveable in 

 a slot concentric with the axis of the wheel 3. 

 This slot is a branch from the cross-bar >-. 

 The smaller the change-pinion is, the nearer 

 will the stud k approach to the vertical line 

 joining the centres of wheels 1 and 3 ; and the 

 more slowly will the plate-wheel 2 be driven. 

 To the spur-wheel 3, a bevel-wheel 4, is fixed, 

 with which the other also revolves loose upon 

 a stud. The bevel-wheel 5, upon the shaft I, is 

 driven by the bevel-wheel 4 ; and it communi- 

 cates motion, by the bevel-wheels 6 and 7, to 

 each of the horizontal shafts G, o, extending 

 along the upper and under tiers of the machine. 

 At the left-hand side of the top part of fig. 1781, 

 the two wheels 6 and 7 are omitted, on purpose 

 to show the bearings of the shaft o, as also the 

 slot-bearings for carrying the shafts or skewers 

 of the bobbins. 



If it be desired to communicate twist in the 

 opposite direction to that which would be given 

 by the actual arrangement of the wheels, it is 

 necessary merely to transpose the carrier-wheel 

 2, from its present position on the right hand of 

 pinion 1, to the left of it, and to drive the tin cylinder by a crossed or close strap, 

 instead of a straight or open one. 



The traverse motion of the guide is given here in a similar way to that of the 

 engine (fig, 1766). Near one of the middle or cross-frames of the machine (see fig. 

 1782), the wheel /, in gear with a spur-wheel h, upon one of the block-shafts, drives 

 also a spur-wheel m, that revolves upon a stud, to which wheel is fixed a bevel-wheel 

 n, in gear with the bevel-wheel o. To wheel o, the same mechanism is attached 



as was described under 

 1/84 



1783 



figs. 1780 and 1781, and 

 which is here marked 

 with the same letters. 



To the crank-knob r, 

 Jiff. 1782, a rod, x, is at- 

 tached, which moves or 

 traverses the guide-bar 

 belonging to that part oi 

 the machine : to each 

 machine one such appa- 

 ratus is fitted. In figs. 

 1783 and 1785, another 

 mode of traversing the 

 guide-bar is shown, which 

 is generally used for the 

 coarser qualities of silk. Near to one of the middle frames, one of the wheels /, in 

 gear with the spur-wheel m, and the bevel-wheel . both revolving on one stud, 

 gives motion also to the wheel o, fixed upon a shaft a', at whose other end the 



