GB544873A - Improvements in method of making elastic yarn - Google Patents

Abstract

544,873. Elastic yarns. UNITED STATES RUBBER CO. July 30, 1941, No. 9679. Convention date, Nov. 19, 1940. [Class 120 (iii)] A balanced single cover elastic yarn, i.e. one in which the cover is wrapped around the core thread in a single operation, is formec by delivering a pretwisted rubber thread and one or more textile strand: or covering yarns along separate converging paths and at independently controlled speeds. to a meeting point, the yarn advancing faster than the thread and both advancing from the point of convergence still at the controlled relative speeds to an adjacent twisting device by which they are twisted together in a direction to remove part of the twist of the thread and place the yarn about the thread so that the thread assumes a central position with the yarn lying helically around if. As shown a roving 15 from a bobbin 16 is delivered by drawing rollers 17, 18, 19 to a guide 20 in line with the spindle 21 of a ring and traveller twisting device 22; the pretwisted rubber thread 10 is fed from the driven spool 11 to driven feed rolls 26 by which it is delivered to the guide 20 alongside the roving 15; in lieu of the roving, one or two yarns may be delivered from bobbins, through tension devices, to a pair of driven feed rolls which deliver it or them to the guide 20 and the feed rolls for the rubber thread may be omitted. The roving or yarn and the thread may be fed to converge towards each other at equal angles at the guide 20.