GB946248A - Improvements in or relating to friction clutches - Google Patents

Abstract

946,248. Friction clutches. CREED & CO. Ltd. Nov. 22, 1962, No. 44204/62. Heading F2C. A coil-spring clutch cornprises a driving or driven drum 13 that is gripped by a self-contracting helical spring 10, the ends 11, 12 of which are respectively fast with a support 4 secured on a flange 1 of a driven or driving shaft 3 and a circumferentially movable element 18 on the flange 1, so that when means move the element 18 anti-clockwise relative to the flange 1 the spring 10 is unwound to release its grip on and contact with the drum 13. Brackets 7 support the spring 10 when expanded and a tension spring 30 between projections 19, 31 respectively fast with the element 18 and support 4 assists the engagement of the spring 10. In Fig. 10, wherein the shaft 3 is the driven shaft, the clutch is disengaged by moving a stop 24 into the path of the project 19 which is thus moved anti-clockwise relative to the flange 1 until it abuts a stop thereon to brake the driven shaft 3. A spring-loaded arm may be mounted on the stop 24 to engage the flange 1 and prevent reverse rotation thereof under the action of the springs when the stop 24 is moved into path of the projection 19. In Fig. 12, the clutch is disengaged by a plunger 29 which moves the element 18 anti-clockwise relative to the flange 1. The plunger 29 may be spring retracted and moved left for clutch disengagement by a solenoid 26 or vice versa. The drum 13 is connected to its shaft 23 through an Oldham coupling 32. The drum 13 is made of sintered metallic material having a lubricant content and has a helical groove thereon to permit the flow of lubricant. The direction of rotation may cause a self-tightening action of the spring 10.