These objects may be effected in several ways; that is, the machinery may be variously constructed, and still embrace the principles proposed. [Fig. 1211.] shows one mode:—a, is the friction wheel; b, the front drawing roller, placed in the drawing frame in the same way as usual; the larger wheel a, constituting the lower roller of the pair of front drawing rollers; c, and d, are the pair of back drawing rollers, which are actuated by geer connected to the front rollers, as in the ordinary construction of drawing machines, the front rollers moving very considerably faster than the back rollers, and, consequently, drawing or extending the fibres of the sliver of wool, as it passes through between them; e, is a guide roller, bearing upon the periphery of the large wheel; f, is a tension roller, which presses the fibres of the wool down upon the wheel a.
Now, supposing the back rollers c and d to be turned with a given velocity, and the front roller b to be driven much faster, the effect would be, that the fibres of wool constituting the sliver, passing through the machine, would be considerably extended between b and d, which is precisely the effect accomplished in the ordinary drawing frame; but the wheel a, introduced into the machine in place of the lower front drawing roller, being made to revolve much faster than b, the sliver of wool extended over the upper part of its periphery from b, to the tension roller f, will be subjected to very considerable friction from the contact; and, consequently, the natural curl of the wool will be taken out, and its elasticity destroyed, which will enable the wool to proceed in a connected roving down to the spindle or flyer h, where it becomes twisted or spun into a worsted thread.
In order to increase or diminish the extent to which the fibres of wool are spread over the periphery of the wheel a, a regulating roller is adapted to the machine, as shown at g, in place of the tension roller f. This regulating roller g, is mounted by its pivots in bearings on the circular arms h, shown by dots. These circular arms turn loosely upon the axle of the wheel a, and are raised or depressed by a rack and a winch, not shown in the figure; the rack taking into teeth on the periphery of the circular arms. It will hence be perceived, that by raising the circular arms, the roller g, will be carried backward, and the fibres of wool pressed upon the periphery of the wheel to a greater extent. On the contrary, the depression of the circular arms will draw the roller g, forward, and cause the wool to be acted upon by a smaller portion of the periphery of the wheel a, and consequently subject it to less friction.
When it is desired to employ steam for the purpose of heating the wool, the wheel a, is formed as a hollow drum, and steam from a boiler, in any convenient situation, is conveyed through the hollow axle to the interior of the drum, which, becoming heated by that means, communicates heat also to the wool, and thereby destroys its curl and elasticity.
Breaking-frame.—Here the slivers are planked, or spliced together, the long end of one to the short end of another; after which they are drawn out and extended by the rollers of the breaking-frame. A sketch of this machine is given in [fig. 1212.] It consists of four pairs of rollers A, B, C, D. The first pair A, receives the wool from the inclined trough E, which is the planking-table. The slivers are unrolled, parted, and hung loosely over a pin, in reach of the attendant, who takes a sliver, and lays it flat in the trough, and the end is presented to the rollers A, which being in motion, will draw the wool in; the sliver is then conducted through the other rollers, as shown in the figure: when the sliver has passed half through, the end of another sliver is placed upon the middle of the first, and they pass through together; when this second is passed half through, the end of a third is applied upon the middle of it, and in this way the short slivers produced by the combing are joined into one regular and even sliver.
The lower roller C receives its motion from the mill, by means of a pulley upon the end of its axis, and an endless strap. The roller which is immediately over it, is borne down by a heavy weight, suspended from hooks, which are over the pivots of the upper roller. The fourth pair of rollers D, moves with the same velocity as C, being turned by means of a small wheel upon the end of the axis of the roller C, which turns a wheel of the same size upon the axis of the roller D, by means of an intermediate wheel d, which makes both rollers turn the same way round. The first and second pairs of rollers, A and B, move only one-third as quick as C and D, in order to draw out the sliver between B and C to three times the length it was when put on the planking-table. The slow motion of the rollers A, is given by a large wheel a, fixed upon the axis of the roller A, and turned by the intermediate cog-wheels b, c, and d; the latter communicates between the rollers C and D. The pinions on the rollers C and D being only one-third the size of the wheel a, C and D turn three times as fast as A, for b, c, and d, are only intermediate wheels. The rollers B turn at the same rate as A. The upper roller C is loaded with a heavy weight, similar to the rollers A; but the other rollers, B and D, are no further loaded than the weight of the rollers.
The two pairs of rollers A, B, and C, D, are mounted in separate frames; and that frame which contains the third and fourth pairs C, D, slides upon the cast-iron frame F, which supports the machine, in order to increase or diminish the distance between the rollers B and C. There is a screw f, by which the frame of the rollers is moved, so as to adjust the machine according to the length of the fibres of the wool. The space between B and C should be rather more than the length of the fibres of the wool. The intermediate wheels b and c, are supported upon pieces of iron, which are movable on centres; the centre for the piece which supports the wheel b is concentric with the axis of the roller A; and the supporting piece for the wheel c is fitted on the centre of the wheel d. By moving these pieces the intermediate wheels b and c can be always kept in contact, although the distance between the rollers is varied at times. By means of this breaking-frame, the perpetual sliver, which is made up by planking the sliver together, is equalized, and drawn out three times in length, and delivered into the can G.