GB858103A - Improvements in apparatus for crimping textile fibres - Google Patents

Abstract

858,103. Crimping fibres and yarns. BANCROFT & SONS CO., J. June 12, 1958 [June 13,1957], No. 18836/58. Class 120(3). Apparatus for crimping yarn or filaments comprises rolls feeding yarn into one end of a crimping and setting chamber against the mass of crimped yarn therein and forcing the mass to advance along the chamber, take-up means removing crimped yarn from the other end of the chamber, and means for driving the rolls at a speed variable inversely with the torque necessary to feed the yarn into the chamber whereby the pressure on the mass is dependent on the torque characteristics of the driving means. The drive to the rolls may include a slipping clutch e.g. a hysteresis clutch the slip of which increases as the load exceeds a predetermined maximum. In addition, the take-up means may be arrested when the level of the mass ir the chamber falls below a predetermined point. As shown in Fig. 1, yarr 19 braked by a tensioner 21 passes through a guide 20 to rolls 18 and is fee into a tube or chamber 14 secured in a block 10 which houses an electrica unit 22 whereby yarn is heated to set the crimp. Crimped yarn is withdrawn through the bore 46 of a member 45 and wound on to a bobbin 55 of a constant speed winder 56. Upwarc movement of member 45, according t( change in level of massed yarn, cause: a flange 53 to engage an adjustable stop 47 whereupon the mounting back pressure increases the torque required to rotate shaft 25 and the speed of rolls 18 decreases or is interrupted as a result of slippage of a hysteresis clutch through which roll 18 is driven from a motor 34 by belt 31 and pulleys 32 and 27. The clutch comprises permanent magnets 36 coacting with discs 37 the gap (hence the transmitted torque) between which is adjustable. Normally shaft 25 is driven so as to feed yarn at a rate exceeding the rate of withdrawal by winder 56, but if the level of yarn mass falls the flange 53 operates a microswitch 51 to stop the apparatus. In an inverted chamber, Fig. 2 (not shown) crimped yarn is withdrawn against a spring-loaded ball closure for the tube 14. As shown in Fig. 3, member 45 may be replaced by a cap 65 sliding movement of a sleeve 66 of which on tube 14 is limited by a stop 67 or operates a stop microswitch 70: the cap also cools the yarn below the setting temperature, before withdrawal. In another embodiment, Fig. 4, a cap 75 forms a fixed cooling chamber and a leaf spring 77, normally depressed against the wall of tube 14 by pressure of the yarn mass, actuates a stop microswitch 78, if it is released. In a modified drive, Fig. 5, a hysteresis clutch, between drive shaft 80 and feed rolls 86, comprises magnet poles 85 secured to the shaft and coacting with a ring 88 carried by one roll 86 journalled on the shaft: a washer 89 determines the air gap.