Thros′tle.
1. (Cotton.) The drawing-frame of the cotton manufacture. The great invention which succeeded the spinning-jenny of Hargreaves. The drawing-frame is for attenuating slivers of fiber by passing them through consecutive pairs of rollers, each pair in the succession revolving at a higher speed than its predecessor. Leon Paul, by patent of 1738, claimed a mode of spinning by rollers, but the device did not come into use. (See spinning.) Richard Arkwright perfected the invention and patented it in 1769. Arkwright's original spinning-frame was fed with rovings which passed between three pairs of rollers of successively increasing speed. The yarns were wound upon bobbins by means of flyers. It was the culmination of several attempts, and possesses the main features of the throstle and the bobbin and flyframe in function, as well as in the relative positions of parts. See spinning, Fig. 5404, page 2271. The bobbin and fly-frame is similar in principle to the throstle, and is adapted for giving a partial twist to the sliver as delivered from the carding-machine or the doubling-frame. The slivers in cans are fed to the coarse bobbin and fly-frame, where they are reduced and partially twisted so as to give them greater coherence, being elongated say 4 1/2 times, The rovings thus produced are wound on bobbins which are placed on the creel of the fine bobbin and fly-frame, by which they are still farther reduced and twisted. These rovings on their bobbins are then transferred to the throstle, a transverse vertical section of which is shown in Fig. 6419. a a are two of the bobbins. The thread, as it is drawn off from these, passes through the drawing-rollers b c d, and then to the spindles. Here it is twisted and wound upon the bobbins. The bobbins h have no rotatory motion imparted to them, but simply rest upon the trays l, and are dragged round by the thread as it twists itself round them, as the fork or fly k revolves much more rapidly than the thread is given out from the drawing-rollers. The up-and-down motion of the bobbins is effected in the following manner:—
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| Throstle. |
