GB687193A - Method for feeding yarn to a knitting machine, having a constant tension and/or output, and yarn feeder for the performance of this method - Google Patents

Abstract

687,193. Knitting-machines. ETABLISSEMENTS PORON. Feb. 13, 1948. [April 15, 1947] No. 4240/48. Class 74 (ii). [Also in Group XXIV] A yarn feeding device, for a knitting-machine, delivers yarn at a constant tension and coinprises a member around which the yarn is wound and which rotates at a peripheral speed faster than the linear speed of the yarns and means for varying the arc of contact of some of the turns of yarn with the rotating member. In one embodiment, yarn 30 makes several turns 31 around a rotating cylinder 2, some of the yarns passing over a member 19. A rod 15 is positioned adjacent the turns 31. When the yarn tension decreases, a weight 22 causes the member 19 to pivot about a point 23 and to move away from the cylinder 2. The turns of yarn on the member 19 are thereby brought into contact with the rod 15 and the driving force on the yarn is reduced to deliver yarn at constant tension. A cone shaped member 10 controlling the delivery of the yarn is positioned near the cylinder 2 and the yarns also pass round the cone. The yarns are guided on the cone by an adjustable guide 27. The cone may be grooved or stepped. In a second embodiment (Fig. 6) the cylinder is replaced by two cylinders 41, rotated in unison by gearing, the yarn passing from the first cylinder along grooves 47 in a fixed central block 49 positioned between the two cylinders 41, round the second cylinder, and on to a cone controlling the yarn delivery. In this embodiment, a member 52 and rods 51 correspond, respectively, to the member 19 and the rod 15 of the first embodiment. With either embodiment, a device (Fig. 7) that relieves the tension imposed on the yarn by the knitting- machine is positioned between the knitting- machine and the yarn feeding device. If the tension at 76 increases, an arm 73 is drawn down and an arm 69 rises causnig rollers 70, 71n to press the yarn between rollers 65-67. A clutch (Fig. 8) to separate the yarn feeding device from the driving shaft of the machine comprises a tooth 87, on a plate 79 on the driving shaft 77, that engages a tooth 84 on a member 80 sliding on the driven shaft 78. A lag may be caused in engagement and disengagement of the clutch by members 92, 83, which-engage a screw thread 82 on the outside of the member 80 and allow the member to be lowered or raised gradually.