Patent GB-770710-A (GB)
Title: Improvements relating to electrically-driven spinning, twisting and winding machines
IPC: H02K17/30
Filed: 1955-02-23
Abstract: 770,710. Bobbin driving means ; tension control. BARMER MASCHINENFABRIK AKT.-GES. Feb. 23, 1955 [Feb. 23, 1954], No. 5454/55. Class 120 (2). [Also in Group XXXV] As shown, an A.C. motor 2 drives a bobbin 3 upon which is wound a thread 4 passing over a feeler roller 8 mounted on a lever 7. The motor also drives a cam 18 moving a thread guide 19 backwards and forwards for laying the thread upon the bobbin, the thread guide being mounted on a rocking lever 20 which is rotated clockwise as the package increases in size. The lever 7 regulates the speed of the motor 2 in accordance with a predetermined value of thread-tension by influencing the magnetic flux of the motor, the tension of the thread being determined by a displaceable weight 21 or an adjustable spring 22. In a modification, Fig. 3 (not shown), the speed of the motor is controlled in response to changes of diameter of the package, and, in a further arrangement, the member for influencing the motor flux is actuated by a cam driven by the motor so that changes of speed are related to the winding- time, Fig. 4 (not shown). The speed variation may be brought about by changing the relative longitudinal positions of the field 31 and armature 32, the adjustment lever 7 rotating drum cam sections 35, 36, to shift the armature by means of a groove in the member 35 which co-operates with pin 38 and roller 39. A magnetic member 44 is fixed to the armature shaft and may be arranged so that the flux of the motor does not tend to disturb the position of the armature when it has been displaced by the lever 7. Alternatively, the magnetic force due to the field may act in one direction or the other so as to oppose or assist the force upon the armature due to the lever 7. The armature is prevented from causing undesired backmovement of the member 7 by arranging that the pin 38 is locked in the cam-groove when such movement tends to take place. Small movements of the lever 7 are prevented from influencing the position of the armature by allowing some movement of the roller 39 in its groove, a brake on a bushing 40 being provided for stabilizing the longitudinal positions of the armature. Another method of allowing the lever 7 to have some freedom of movement without influencing the position of the armature, is provided by stops 47 adjustably arranged in a slot of the drum section 36, the lever being mounted independently of the drum by means of pin 51 in a bearing 50 and being movable between the stops without moving the drum. With this construction, undesired change of the position of the armature is prevented by a brake 49 acting on the drum section 35. The package is driven by a toothed wheel 10 keyed to the armature shaft. In other arrangements the longitudinal positions of the field and armature are fixed, the flux being influenced by a tube of magnetic material which passes between the field and armature. The base of the tube may be of non-magnetic material, Fig. 10 (not shown), in which case advance of the tube between the armature and field, as the tension of the thread decreases, causes the speed of the motor to increase. If the base of the tube is made of magnetic material, it is caused to advance between the field and armature as the thread-tension increases so that the speed of the motor is reduced, Fig. 11 (not shown). The motor may be fitted within the package of thread being wound, Fig. 12 (not shown). Modifications in which the field revolves instead of the armature, and in which the field is displaceable axially are referred to.