GB1134803A - Method and apparatus for the production of crimped yarns - Google Patents

Abstract

1,134,803. Crimping yarns; regulating thread tension. ZINSER TEXTILMASCHINEN G.m.b.H. 28 July, 1966 [28 July, 1965], No. 33940/66. Headings DID and DIF. In the production of crimped multifilament or staple fibre yarns of synthetic thermoplastic materials, such as polyamides, polyesters, polyacrylonitriles, by a method in which at least two separate yarns are fed under tension to a common twisting zone and, after heatsetting of the false-twist thus produced, are separated at a separating point and withdrawn under tension at equal speeds to be finally spooled, the separated yarns reach run through at least one extension zone in which the tensions of the yarns are so controlled and regulated within their elastic range that, when a relative difference in length of the yarns occurs, the tension of the shorter yarn is is increased and the tension of the longer yarn is simultaneously decreased. In the apparatus of Fig. 1, a thread guide 2 limits lateral oscillation of yarn in the twisting zone 1 and enables smooth separation of yarns 6 and 7. If the tension in these yarns are equal and the yarns between the separating point 3 and the draw-off points 52, 53, at the nips of rollers 22, 23, are of equal length, then guide rollers 12 and 13 are symmetrically disposed about the guide 2 and the yarns run over corresponding portions of conical frustra 8 and 9 of equal diameter so that their speeds over coupling roller 10 are equal. However, if the tension of one yarn increases relative to the other, then parallelogram links 16, 17, are urged to one side or the other so that the yarns run over portions of the frustra 8, 9, of different diameters and the tensions therein are thereby correctively and quickly adjusted whereupon the central position of the guide appliances 50 is restored. In a modified apparatus, Fig. 4, yarn guide appliance 51 has a guiding device 40 transversely displaceable by means of guide rails 20 or 21a and 21b and corresponding rollers 25. The rails are joined to form a rigid frame 19 on which guide and deflecting rollers 12, 13, and 14, 15, are mounted. Rollers 25 are fixed and support frame 19 in its horizontal position so as to be displaceable transversely to the run of twisted yarns. Coupling roller 10 comprises a central bearing in a block 26.