Patent GB-778346-A (GB)
Title: Apparatus for crimping yarn and like continuous filamentary material
IPC: C07J5/00
Filed: 1955-09-14
Abstract: 778,346. Crimping and winding yams; roller arrangements in textile spinning &c. machines. BANCROFT & SONS CO., J. Sept. 14, 1955 [Oct. 8, 1954; Nov. 22, 1954 ; Feb. 11, 1955; March 1, 1955], No. 26349/55. Classes 120 (2) and 120 (3). In apparatus for crimping yarn or like filamentary material comprising a bored member forming a crimping chamber into opposite ends of which feed rolls and delivery means supply the yarn and withdraw it under tension, the movement of a member bearing against a mass of yarn in the chamber to accommodate changes in the quantity thereof actuates control means to vary the slip of the yarn through the feed rolls or the delivery means in such manner as to maintain a constant quantity of yarn in the chamber. In the operation of the apparatus shown in Fig. 2, yarn 35 passing through a guide 59 is fed by constant-speed rolls 24 and 29 into a tube 14, secured within a sleeve 13 in a block 10, against the pressure exerted by a mass of crimped yarn 46 therewithin and take-up rolls 58 withdraw the yarn through a plunger 45 resting on the yarn mass 46: when the plunger 45 moves due to variation in the mass, it actuates a lever 49 which moves a link 54 to turn (or allow a spring to turn) a screw 40 and thereby adjust the pressure exerted by a spring 36 which, acting through a link 38 connected to a pin 39 on a pivoted arm 25, alters the frictional pull of the rolls 24 and 29 and varies correspondingly the slip of the yarn therebetween. As shown in Fig. 4, the spring 36 is replaced by a spring 61, attached to a pin 62 on the arm 25 and to an adjustable screw 63, for holding the rolls 24 and 29 in pressure engagement with the yarn 35, and the spacing of the rolls is varied by a screw 65 threaded through a plate 11 and bearing against the arm 25. In the apparatus of Fig. 5, the rate of withdrawal of the crimped yarn 46 is controlled by the plunger 45 movements of which actuate a lever 49 to turn a pin 81 bearing against a boss 82 of a pivoted arm 74 to vary the clearance and hence the slip of the yam between delivery rolls 70 and 71 (the latter mounted on the arm 74) which are held in gripping contact by an adjustably-anchored spring 76. An embodiment, Fig. 7, comprises a delivery roll 70a (mounted on a fixed bracket 73a) and a delivery roll 71a (carried on a pivoted arm 74a) held in pressure engagement by a pivoted spring 86 the effect of which is varied by rotation of a screw 89 as determined by the lever 49. In the apparatus shown in Fig. 8, crimped yam 46 is withdrawn from the crimping chamber by a constant-speed winder, normally driven at a speed slightly higher than that required to maintain a constant level of yarn in the chamber, and is taken up on a spool 90 driven by a roll 92. The lever 49 is normally out of contact with a microswitch 116 when the plunger 45 is at a predetermined level but when the plunger falls and actuates the switch 116 to energize an adjustablymounted solenoid 109, the movement of the core 108 thereof acts against the spring 113 and through a spring 107 to rock a lever 106 and operate a pawl 104-and-ratchet 103 by which a bell-crank lever 100 is rotated about its pivot 99 to reduce the pressure (and so increase the slip) between the winding 91 and the roll 92: when the level of yarn in the chamber is restored, the switch 116 is released so that the solenoid 109 is de-energized to release the core 108 which together with the lever 106 is returned by the spring 113 to normal position. The movement of the bellcrank lever 100 caused by the increasing diameter of the winding is lost by the ratchet 103 sliding inoperatively on the pawl 104 and a counterweight 121 ensures a predetermined constant pressure of the winding on the roll 92 (for normal wind-up) as the weight of the winding increases. In a modification, Fig. 10, the springs 107 and 113 are replaced by a link 125 and a spring 126 when the plunger 45 falls and closes the microswitch 116, the solenoid 109 is energized and exerts a pull to raise the windings 91 from the roll 92. The chamber may be heated, as by an electrical heating unit 120. Specification 754,595 is referred to.