Patent GB-817820-A (GB)
Title: Tension control in twisting machines and the like
IPC: B65H59/10
Filed: 1956-10-26
Abstract: 817,820. Automatic tension control systems. HASKELL-DAWES MACHINE CO. Oct. 26, 1956 [Jan. 13, 1956], No. 32669/56. Class 38 (4). [Also in Groups IX and XXV] To keep the tension constant in a strand twisting machine the following are provided: a winding reel rotatable by a drive which can be varied by electrically-operable means (e.g. a friction clutch), means (e.g. a flyer) rotatable about the reel at constant speed, means (e.g. capstans) for supplying strand material at a constant rate to the reel, and adjustable means responsive to the slack or pull of the strand to apply a variable voltage to the electrically-operable means in response to variations in the rate at which the strand is taken up on the reel. The drive is provided by a constantspeed motor 36, Fig. 1, through a clutch 41 and.a two-part pulley 35. One part drives a winding- reel 23 through an electromagnetic clutch 26 and a pulley 33, and the other a flyer 57 through a pulley 39 ; it also drives, through a reduction drive, a worm-shaft 67 of the traverse mechanism. This comprises a ring 60 carrying a pulley 56 and mounted to slide on horizontal members 55, 57 of the flyer and to rotate in a channelled outer ring 61 which moves to and fro as the shaft 67 is rotated. The strand having been formed from a number of components in a sizing- die, passes through hollow shafting to a pulley 53 on the flyer and thence around capstans 42, 43 which are rotated from the flyer to feed the strand forward at a constant rate. It then forms a loop between pulleys 98 and 54 on the flyer over a sensing pulley 93 on a plate 91. As the tension varies in the strand, the size of the loop varies the strand engaging more or fewer of the idlers 92, and with the change in the pull on the sensing-pulley relative movement occurs between the plate and a ring to 89 to which it is frictionally- or spring-coupled. The plate 91 is rotatably mounted on a sleeve which is driven by the flyer and the ring 89 is also driven by the flyer through a gear 46 and the capstans: accordingly when the members 91 and 89 move relatively, so do the plate and sleeve, whereupon a potentiometer 87 is actuated through sprockets and chains to vary the torque transmitted by the clutch 26 to the reel. The potentiometer is adjustable; the point at which the members 91 and 89 can be pre-set by adjusting the spring 96 on the couplings 95 according to the required working tension: and a brake 73 is provided in the drive to the reel to off-set the momentum of the wound reel while it is stopping. The controlling circuit is shown in Fig. 15. The main potentiometer 87 controlling the clutch 26 is preset by auxiliary potentiometers 88, 131. This clutch and the motor 36 are controlled by a switch 130, but the brake 73 and a clutch 41 in the main drive are controlled by a relay 78 through start and stop switches 79, 80. The relay may be energized from supply conductors 81 through a transformer 82 by momentarily closing the switch 79, and locks itself in through contacts 83. Contacts 85 controlling the brake 73 are now opened and those controlling the clutch 41 closed. On opening the stop switch 80 the relay is disengaged and the contacts 85 closed to engage the brake 73.