Patent GB-1381230-A (GB)
Title: False twist crimping machine for crimping thermoplastic filaments
IPC: D02G1/08
Filed: 1973-06-08
Abstract: 1381230 Crimping fibres; false-twisters; thread guides BARMAG BARMER MASCHINENFABRIK AG 8 June 1973 [8 June 1972] 27336/73 Headings DID and D1F In a filament false-twist crimping machine, a deflection unit preceding a frictional falsetwister in relation to the travel of the running filament contacts the latter and makes oscillating or circular movements perpendicularly of the direction of filament travel and thereby imparts corresponding e.g. oscillating and/or ballooning, movement to the filament in a cooling zone between a heater and the succeeding twister. The deflection unit may be separate from or form part of, or be attached to, the twister and may be driven independently or directly or indirectly therewith or therefrom. In the described embodimens the path of the filament immediately approaching the, or the first, friction surface of the false-twister is at a constant angle to the axis of rotation thereof. As shown in Fig. 1, a filament 2 withdrawn from a bobbin 1 by nip rollers 3 and guided over and in contact with a heated plate 4, passes through a cooling zone 5, wherein it is oscillated as a result of contact with the edge of a non-circular rotating disc 12, thence through a false-twister 6 and nip rolls 7 (interconnected with rollers 3 through an adjustable gear so that the filament passes through the crimping zone under an adjustable tension) to be wound by traverse mechanism 8 into a bobbin 9. Fig. 2 shows a circular or elliptical disc 12 mounted eccentrically and tilted on the shaft 18 of a (friction) twisting element 10 so that its periphery 13 always contacts and oscillates (with amplitude f) the filament. Element such as 10 or a ring (the inner periphery of which frictionally twists the filament) may be the first of a series thereof mounted on a shaft and/or coaxially and/or an offset number thereof, Figs. 5 and 6 (not shown) providing several friction twisting surfaces between which the filament may follow a tortuous path. The embodiment of Fig. 3 comprises a friction sleeve 20 secured to a rotating, belt-driven tube 21 and carrying an eccentrically connected, obliquely truncated section 25 providing a wobbling-rotating edge 27 by which the filament is oscillated: Fig. 7 shows similar apparatus wherein the filament is guided through a friction sleeve parallel to its axis of rotation and a wobbling edge 54 is formed by truncating the friction timing at the inlet end. In the apparatus of Fig. 8, the filament is false-twisted between a driven roller 70 with a friction covering and a freely rotatable steel wheel 71 and is oscillated by an eccentrically mounted cylinder section 75 housing an obliquely arranged encircling bead 77 which forms a wobbling, rotating eccentric edge 73 over which the filament travels. The apparatus of Fig. 9 comprises eccentrically mounted, synchronously rotated discs 81, 82, 83, defining a filament confining passage 84 which revolves on a circular path 85 to impart a ballooning movement to the filament passing therethrough: The wobble stroke and eccentricity of deflecting edge(s) may be adjustable e.g. the body providing such edge(s) may be eccentrically movable around a cylindrical or (part-)spherical member, Figs. 10-12 (not shown).