Electro-magnetic spring-wound clutch

摘要

Input and output members (19), (28) and a clutch disc (32) are coaxially rotatable relative to each other, the clutch disc (32) being frictionally engageable with the input member (19). A coil-would spring (33) is wound around the input member (19) and connected at its ends to the clutch disc (32) and output member (28). An electromagnetic coil (26) may be energized to attract the clutch disc (32) into frictional engagement with the input member (19), causing the coil-wound spring (33) to tightly wind around the input member (19) and drivably connect the input member (19) to the output member (28). A spring (41) quickly and smoothly disengages the clutch disc (32) from the input member (19) when the coil (26) is de-energized. A plurality of pins (36) extending through the clutch disc (32) ensure parallel movement of the clutch disc (32) toward and away from the input member (19). The spring (41) is in the form of an annular plate spring and is resiliently flexed by means of hard rivets (43) projecting from a cover (34). The spring (41) slides on the rivets (43) during engagement and disengagement of the clutch disc (32), thereby minimizing friction and abrasion.