Drawing-frame

—Three of these cans are removed to the drawing-frame, which is similar to the breaking-frame, except that there is no planking-table E . There are five sets of rollers, all fixed upon one common frame F , the breaking-frame, which we have described, being the first. As fast as the sliver comes through one set of rollers, it is received into a can, and then three of these cans are put together, and pa ed again through another set of rollers. In the whole, the wool must pa through the breaker and four drawing-frames before the roving is begun. The draught being usually four times at each operation of drawing, and three times in the breaking, the whole will be 3 + 4 + 4 + 4 + 4 = 768; but to suit different sorts of wool, the three last drawing-frames are capable of making a greater draught, even to five times, by changing the pinions; accordingly the draught will be 3 + 4 + 5 + 5 + 5 = 1500 times. The size of the sliver is diminished by these repeated drawings, because only three slivers are put together, and they are drawn out four times; so that, in the whole, the sliver is reduced to a fourth or a ninth of its original bulk. The breaking-frame and drawing-frame which are used when the slivers are prepared by the combing-machines, are differently constructed; they have no planking-table, but receive three of the perpetual slivers of the combing-machine from as many tin cans, and draw them out from ten to twelve times. In this case, all the four rollers contribute to the operation of drawing: thus the second rollers B , move 2 1 ⁄ 2 times as fast as the rollers A ; the third rollers C , move 8 times as fast as A ; and the fourth rollers E , move 10 1 ⁄ 2 times as fast as A . In this case, the motion is given to the different rollers by means of bevelled wheels, and a horizontal axis, which extends acro the ends of all the four rollers, to communicate motion from one pair of rollers to another. There are three of these systems of rollers, which are all mounted on the same frame; and the first one through which the wool pa es, is called the breaking-frame; but it does not differ from the others, which are called drawing-frames. The slivers which have pa ed through one system of rollers, are collected four or five together, and put through the drawing-rollers. In all, the slivers pa through three drawings, and the whole extension is seldom le than 1000 times, and for some kinds of wool much greater. After the drawing of the slivers is finished, a pound weight is taken, and is measured by means of a cylinder, in order to ascertain if the drawing has been properly conducted; if the sliver does not prove of the length proposed, according to the size of worsted which is intended to be spun, the pinions of some of the drawing-frames are changed, to make the draught more or le , until it is found by experiment that one pound of the sliver measures the required length.