GB562682A - Improved method and means for doubling yarns - Google Patents

Abstract

562,682. Doubling yarns. BRITISH CELANESE, Ltd. Sept. 17, 1942, No. 13111. Convention date, Sept. 19, 1941. [Class 120 (ii)] Yarns of different twist shrinkage characteristics, i.e. characteristics which affect the shrinkage of the yarns on twisting, are doubled by feeding them at different rates to the feed roll of a twisting and doubling spindle and doubling them with such a degree of twist that the component yarns in the resulting doubled yarn are substantially equal in length. As shown, the yarns A, B are drawn from a creel by the positively driven feed roller 6 of the doubling and twisting spindle and, from a detector arrangement 4, 5, pass around grooves 24, 25 in a wheel 22 rotatably mounted on a shafts 19 to the roller 6 and a grooved idler roll 9 for guiding the yarns several times about the roller 6. The grooves 24, 25 are surfaced with a material having a high coefficient of friction to prevent the yarn slipping therein and the circumference of the groove 25 measured at the bottom thereof is slightly less than that of the groove 24 so that the yarn A of higher twist located in the groove 24 travels faster than the yarn B of lower twist in the groove 25 when the doubling twist given is in the same direction as the twist in the yarn A ; if the doubling twist is in the opposite direction to the twist in the high twist yarn, that yarn is fed at the lower rate. The yarn drawn by the feed roll 6 and running in the groove of smaller circumference drives the wheel 22 and feeds the yarn running in the groove of larger circumference to the feed roll. In modifications, a pair of grooved wheels having grooves of different circumferences, or one or a pair of conical rollers with means for guiding the different yarn to parts of the roller or rollers of different diameters, are used, and the axes of the pair of conical rollers may be inclined to one another at a small angle in planes at right angles to the paths of the yarns.