GB461931A - Improvements in elastic yarn and process of making the same - Google Patents

Abstract

461,931. Covering cores. CLAYTON, T. A. (United States Rubber Products, Inc.) Dec. 6, 1935, No. 33915. [Class 109] [Also in Group IX] Elastic yarns comprise a tensioned and twisted elastic core and a covering wrapped helically around in a direction opposite to the twist of core and holding the core in tension, the twist in the core being sufficient to balance the helical windings of the covering. The relation between the number of twists in the core to balance the helical windings of the cover varies with the tension, size and flexibility of the core, and the size and flexibility of the covering. Constructional data are given of different yarns made in accordance with the invention, a balanced condition being defined as one in which the yarn hangs straight in the skein without tending to twist or kink. The covering may comprise a wrapping of loosely aggregated fibres, such as drafted roving 36, Fig. 3, and a second wrapping of spun yarn may be wound in the same direction as the first ; or a number of yarns 37, Fig. 4, may be used in the second wrapping to sheath the inner soft cover of roving ; or spun yarn 38, Fig. 5, may be wrapped around the core. Cotton, wool, worsted, spun or unspun silk, spun or unspun rayon, or suitable combinations of such materials may be used for the covering. The core is preferably of rubber such, for example, as that produced as described in Specification 214,615, [Class 70]. The yarns may be made on any spinning-machine. As shown in Fig. 1, rovings 2 are drawn by rollers 6, 8, and are twisted by ring and traveller apparatus around a core 10 of twisted and tensioned rubber drawn from a braked bobbin, a second covering being drawn from a bobbin 19. The roving may be drafted to the required extent in a separate machine, and is then led with the core to common feed rolls in a machine, Fig. 2 (not shown) ; a machine of this kind may be used to impart the original tension and twist to the core. Yarns comprising a twisted core and a covering 38, Fig. 5, of spun yarn may be formed on a machine such as is ordinarily used for covering an untwisted core with two oppositely wound coverings, the core being carried by the first hollow spindle and twisted at delivery by a ring and traveller arrangement and then passed through the second spindle which carries the covering yarn.