GB779015A - Improvements relating to devices for regulating yarn tension - Google Patents

Abstract

779,015. Thread tensioning mechanism. DEERING MILLIKEN RESEARCH CORPORATION. June 1, 1955 [June 1, 1954], No. 16220/54. Class 120 (2). A device for regulating yarn tension comprises a number of alternate fixed and movable tensioning members around which the thread passes in a partial wrap about each member to acquire tension frictionally according to the angle of wrap, a biasing device to urge the movable members in a direction transverse to the general direction of the path of the thread to increase the angle of wrap, which device exerts a force on the movable members which increases as they move in the direction of the force and decreases as they move in the opposite direction, and a pinch tensioning device arranged in advance of the tensioning members to control the entry tension of the thread. In the arrangement shown the fixed members are small plates 2 secured in channels 4 in a base member 6 and the movable members comprise small cylindrical members 8 at one end of each of which is press fitted into a shaft 10 rotatably mounted on the base 6. A pair of tension pads 16 and 18 are mounted on the base 6 and form the inlet tensioning means. One end of a light coiled spring 22 bears against the upper surface of the pad 18 and the other end is welded to the upper end of a stiff wire 24 fixed to the shaft 10. The lower end of the wire 24 is bent downwardly and carries at its lower end a vein 26 which is disposed in a dashpot 28 to dampen the movements of the shaft 10. A fine strong cord 52 is connected to the lower end of the wire 24 and at its upper end to a spring 50 connected to the lower end of a screw 44 which is adjustable in a bracket 30. Thus the tension of the spring 50 acting through the cord 52 and wire 24 tends to rotate the shaft 10 in a direction to force the fingers 8 downwardly between the fixed elements 2 and to increase the pressure applied by the spring 22 to the upper tension pad 18. When the shaft 10 is rotated as a result of an increase in the tension in the yarn, the spring 50 is extended and hence the tension thereof is increased. At the same time however the distance between the axis of shaft 10 and the cord 52 is decreased and the resultant effect is that the effective restoring moment acting on shaft 10 is substantially decreased. Vice versa when the tension in the yarn decreases the movements of the shaft and therefore the force which the tensioning elements 8 exerts on the yarn is increased. The initial tension in the spring 50 can be adjusted by the screw 44 and the initial leverage of the cord 52 can be adjusted by moving the screw 44 in a slot 38 in the bracket 30. In a second embodiment magnetic means are used to provide the restoring force and a double disc type of the tensioning means is provided as the inlet tensioner.