ES314121A1 - A drafting device for textile fibre spinning machines - Google Patents

Abstract

Drafting apparatus comprises, at each spinning position, two or more groups of rollers, each group comprising two pairs of rollers, the rollers of one pair being each provided with an apron, and the active run of the aprons in a group being longer than the run(s) which precede it considered in the direction in which the sliver travels the position of each group is adjustable along guides and the top rollers in each group are carried by a tilting arm loaded by a spring, means being provided for simultaneously adjusting the load of the upper rollers of corresponding groups at a number of spinning positions. In a preferred form, there are two groups the front upper rollers of each group are arranged in pairs joined by a common shaft 28 or 75 and supported in a tilting arm 32 or 76, while the corresponding lower rollers 24 or 72 are continuous throughout the machine. Connected to each arm 32 or 76 is a hook 46 or 86 embracing a tie-bar 48, 88 connected by a threaded, adjustable connector 49, 89 to a loading-spring 50, 90. The loading at individual groups can be adjusted by turning the connector 49, 89 the loading of corresponding groups at a number of spinning positions can also be simultaneously adjusted. To this end, the springs are each connected to one arm of a bell-crank pivoted at 94, Fig. 2, to a fixed part. The other arm of each bell crank of the corresponding groups at a number of spinning positions is connected to a common bar 100 mounted to slide in fixed guides, e.g. 102, Fig. 1, one end of the bar is threaded into a nut 106 integral with a worm meshing a wheel which can be rotated by a handle applied at 116, so that the position of the bar, and hence the loading of all the upper rollers can be varied, markings 105 indicating the value of the loading. Each group comprises a double apron 16, 18 or 56, 58. The aprons 16, 18 are each trained around a roller and a nose bar: of the aprons 46, 58 the lower one is trained around rollers 52, 56, is tensioned by a roller 64, and supported by a plate 62, while the upper one is trained around a roller 54 and a nose-bar 66 tensioned by a rod 68 pivoted on roller 54 and acted on by a spring 70. The front upper rollers in each group are caused by a hook 30 holding the neck between the twin pair by a ball-catch. Fig. 3, not shown. The hook 46 or 86 supporting the tie-bar 48 or 88 is carried by a sleeve eccentrically mounted in the corresponding tilting-arm and adapted to be rotated by a handle 44 to lower the hook and relieve the loading so that the lifting-arm can be raised.