GB1469858A - Method of texturising yarn and a stuffer crimper - Google Patents

Abstract

1469858 Stuffer crimpers INDIAN HEAD Inc 31 May 1974 [1 June 1973] 24160/74 Heading D1F A stuffer crimper for crimping continuous filament yarn 320, e.g. polyester or nylon yarn, comprises a heatable crimping chamber 26 having a channel 36 therethrough; driven rolls 38, 40 for feeding the yarn 320 into the channel 36; crimp control rolls 82, 84 extending into the channel 36 with (a) a portion of the channel 36 between the rolls 38, 40 and 82, 84 defining a confined crimping zone into which the yarn is fed against a core 328 of crimped yarn so as to be crimped and become part of the core and (b) the portion of the channel 36 between the rolls 82, 84 and the end of the chamber 26 opposite the rolls 38, 40 defining a setting zone; and means for driving the rolls 82, 84 independently of the rolls 38, 40 to control the pressure on the core 328 in the crimping zone by regulating the relative rotational velocities of the rolls 38, 40 and 82, 84. In the embodiment described, the short lower portion of the channel 36 has an elliptical transverse cross-section whilst the remainder is of rectangular section. A saddle 42, Fig. 3, is defined by the lower end of the chamber and has arcuate surfaces 44, 46 to fit closely about the rolls 38, 40, felt pads 52 mounted on the surfaces 44, 46 contacting the rolls 38, 40. Electrical heating elements 53, 55 extend parallel to the channel 36 and a third element 57 extends transversely thereto. The shafts 54, 86 of the rolls 38, 82, respectively, are rotatably mounted in a housing member 18 pivotable about a shaft 20 between a closed position, full line position of Fig. 1, and an open position, broken line position. In the closed position, gears on the shafts 54, 86 mesh with gears on shafts 56, 88 of the rolls 40, 84 respectively. A handle 122, Fig. 1, is engaged on pins 136 on a frame 118 attached to the member 18 and a cable 124 extends through the back of the handle 122 around a pivotally mounted pulley 128 and has a weight 130 affixed to the end thereof to urge the member 18 closed. When the member 18 is opened, the handle 122 is pulled off of the pins 136 and engaged on pins 140 on a fixed frame member 14. The yarn is fed to the rolls 38, 40 by a split cam 142, Figs. 1 and 10, comprising yarn guiding members 144, 146 fixed to flanges 148, 150 mounted on a shaft 152, the members 144, 146 defining a helical slot 160 therebetween and the flanges 148, 150 being connected by spaced polished rods 156. A belt 186 drives the rolls 38, 40 in synchronism with the cam 142. A belt 190 drives the rolls 82, 84 and is independent of the belt 186. A cooling tower 196, Figs. 1 and 15, has a channel 202 aligned with the channel 36 and through which a coolant, e.g. compressed air, is circulated via openings 210. A slug 212 rides on the core 328 of yarn in the channel 202 and is shaped as shown in Fig. 17 with a permanent magnet 224 thereon. Four magnetically sensitive read switches 230, 232, 234, 236 are mounted in a case 226 secured to the side of the tower 196 and are operable by the magnet 224. In operation, the yarn 320, Fig. 1, is fed from a supply through a tension control mechanism 322 and over a preheater 325 into the slot 160 of the cam 142 to engage the rods 156. The slot 160 traverses the yarn 320 back and forth axially of the rolls 38, 40 which feed it into the channel 36 against the core 328 causing the yarn to collapse longitudinally and fold over forming crimps which become part of the core. By controlling the speeds of the rolls 38, 40 and 82, 84 the crimping force on the yarn is accurately controlled. The rolls 82, 84 feed the core 328 out of the crimping zone into the setting zone and then into the cooling channel 202. The crimped yarn is withdrawn through a channel 222 in the slug 212 and wound at 330. As the yarn is withdrawn from the tower 196, the upper end of the core 328 and thus the slug 212 move vertically dependent upon the yarn withdrawal rate and the rate of upward movement of the core. The switches 230, 236 are safety limit switches so that when the magnet 224 closes these switches the drives for the crimper, i.e. the cam 142, the rolls 38, 40 and 82, 84, are deactivated. In addition, closure of the switch 236 deactivates the winder 330. During normal operation, closure of a switch 232 by the magnet 224 causes the winder 330 to be driven at a predetermined speed to withdraw the yarn at a rate greater than that at which it is fed into the tower 196. When the slug 212 falls and the magnet 224 closes the switch 234, the winder 330 is driven at a speed less than the predetermined speed to withdraw yarn at a rate slightly less than that at which it is fed into the tower 196 until the switch 232 is again closed. Thus, the upper end of the core 328 is maintained within a predetermined range. In a modification, Fig. 14, the cam 142 is replaced by a cam 300 comprising two generally semi-circular guiding members 302, 304 having helical yarn guiding surfaces 306, 308 and an elliptically shaped cam 314 secured to the shaft 152. In use, the yarn rides on the cam 314.