GB824942A - Improvements in apparatus for crimping yarns - Google Patents

Abstract

824,942. Crimping and tensioning yams; stopping and starting textile spinning &c. machines; twist tubes. SOC. D'ETUDES ET DE RECHERCHES DE MATERIEL TEXTILES SERMATEX. April 5, 1956 [April 8,1955(2)], No. 10431/56. Classes 120(2) and 120(3) [Also in Group XI] Apparatus for crimping yarns by false-twisting comprises a heating device and a rotary spindle through which yarn is drawn and which twists the length of yarn upstream and untwists the downstream length therefrom. The spindle has an oblique exit channel leading to an axial extension provided with at least one retaining and guiding means for convoluting the yarn therearound and braking the yarn so that tension in the downstream length is independent of and is much greater than tension in the upstream length and the yarn is released along the line of the spindle axis. As shown, yarn 1 passes from a cop 2, through an eye 36, over a free pulley 37, then in a zig-zag path provided by hooks or eyes 8, 9, 10, 11, the angular disposition of which may be altered to adjust the tensioning effect thereof, through a heater 3 and a false-twisting spindle 4, around a compensating pulley 41 mounted on a spring- loaded and centi-ed lever 42 so that slight lateral movement of the pulley are in line with the spindle axis, and crimped yarn is wound on a bobbin 5. Spindle 4 mounted in a frame 20 comprises a tubular member 19 having a coaxial passage terminating in a curved portion 21 leading the yarn 1 to an eccentric outlet aperture 22, thence around, and through holes 24 (Fig. 3) or notches 25 (Fig. 4) in, an extension 23 the tensioning effect of which is adjusted according to the number of holes or notches used Spindle 4 is driven by a belt 26 which may serve several twisting stations and/or impart opposite rotation to adjacent tubes, as at 19, enabling oppositely twisted yarns to be taken up on one bobbin. A brake is constituted by a spring-biased lever 27 carrying a shoe 28 which is engaged with and disengaged from a disc 29 by movement of a handle 31 acting through spring 32. Auxiliary yarn advancing elements (not shown) may be interposed between cop 2 and pulley 37 to equalize yarn tension in the zone thereof. The heater device, Figs. 6 and 7, comprises a tube 7 for passage of yarn therethrough surrounded by a metallic e.g. steel, heat-accumulating mass 106, insulation layer 111, and plates 112 112a within a casing formed by a cylinder 101 and plates 102, 103. Mass 106 has passages, as at 107, housing electrical heating elements, as at 108, connected to pins 109, 110 whereby the heater is connected to electrical supply: a tube 114 fixed in a blind hole 113 may house temperature-measuring means e.g. thermometer 115 or a thermocouple. Yarn having a double crimp configuration, i.e. helically coiled about a helically coiled axis, Fig. 5 (not shown) may be produced by overtwist, e.g. by subjecting 20 and 70 denier polyamide yarn to false-twist of 7,000 or 4,000 turns per metre.