GB602915A - Improvements in warp knitting machines - Google Patents

Abstract

602,915. Knitting-machines. AMERICAN VISCOSE CORPORATION. Dec. 5, 1945, No. 32866. Convention date, March 27. [Class 74(ii)] To maintain a constant tension on the yarns being supplied from a warp beam to the needles of a warp knitting-machine, the path of the yarn is decreased or increased in length depending on the demand of the knitting operation. As described, yarns from two frictionally driven warp beams 2, pass over tensioning bars 11, carried by pivotally mounted and spring biassed levers 12 and thence to the warp guides G<1>, G<2>. Rods 19 are connected at one end, by a pin and slot connection, to the levers 12 and at the other end, by pivoted arms 18, to followers 17 operated by cams 16 on the main cam shaft 15. The operation of the tension bars 11 is such that when the yarn is being fed to the needles or the needles are drawing loops through the previous course loops, the bars 11 are lowered by the action of the cams 16 effecting an appropriate movement of the rods 19 to shorten the path of the yarns and to allow the yarn tension to remain constant for the increased demand. After the knitting operation the bars return to their normal positions under the action of the springs 14. Alternatively the yarn may pass over an eccentric roller which is timed to raise and lower the warps at the appropriate knitting operation. The warp beams may be driven by a single roller or by two rollers or by a belt passing between two rollers, and the ends of the beam may be disposed in guide slots.