GB936178A - Improvements in or relating to the spinning of textile yarns - Google Patents

Abstract

936,178. Lap-forming machines; drafting arrangements. COTTON, SILK & MANMADE FIBRES RESEARCH ASSOCIATION. Oct. 6, 1959 [Oct. 7, 1958], No. 31912/58. Classes 120 (1) and 120 (2). [Also in Group XXXV] In a process for spinning textile yarns, a property is measured before processing takes place in a machine so as to control the machine to correct for short-term fluctuations in the property and the property is measured after processing so as to control the machine to compensate for fluctuations in the property which are long term relative to the processing time. As shown, Fig. 1, cotton is fed at a constant rate from a feed lattice 20 via a pedal roller 21, to a scutcher comprising a beater 11, a top cage 12, a bottom cage 13, calender rollers 14-17 and lap rollers 18, 19. The thickness of the cotton passing over the pedal-roller is measured by a pedal assembly pivoted at a knife-rail 23. The pedal assembly, through links 22, 24 is coupled to a lever 25 pivoted about a nut 26 connected to a bell-crank 28 actuating a plunger 29 of a valve 30. Variation in the thickness of the cotton is compensated by the valve varying the speed of an hydraulic motor 31 driving the pedal roller 21 through a worm and wheel 34, 35. The motor is supplied with fluid from a tank 32 by a pump 32. The output of a detector 36, responsive to the position of the calender roll 14, is dependent on the thickness of the processed cotton and through an amplifier 37a energizes a servomotor 37b which through a gear-box 37c and a worm and wheel 38, 40 drives a screw 41 to position the nut 26, pivoting lever 25, so as to correct longterm fluctuations in the thickness of cotton delivered by the machine. In a modification, the pedal roller is driven via a continuously variable gear from the calender rolls, the pedal assembly varying the gear ratio. In a drafting machine, Fig. 3, comprising front rollers 59, 60 back rollers 47, 48 and measuring rollers 49, 50, the output of a detector 36, responsive to the movement of the roller 59, through a time delay unit 62 and amplifier 63 controls an actuator 64 varying the ratio of a gear 55, 56 through a link 70. A pivot 71 of the link 70 is positioned in dependence on the relationship between the output of a detector 65 and a reference signal 67 by a servomotor 68 through an amplifier 66.