GB864521A - Improvements in or relating to friction clutches - Google Patents

Abstract

864,521. Friction clutches ratchet clutches; slip couplings gearing for stopping and starting machinery. FRANCAISE DU FERODO S.A. Nov. 6, 1958 [Nov. 9, 1957], No. 35740/58. Class 80 (2). The driven disc 24 of a clutch for a motor car &c. is connected to an output shaft 11 through torsional vibration damping friction rings 71 in parallel with the usual helical springs 33, arranged tangentially in holes 32 in the disc and in holes 34 in a slip coupling disc 36 mounted upon a ratchet clutch 45 carried by a hub 26 keyed to the output shaft, the ratchet clutch overrunning when the output shaft 11 tends to drive an engine shaft 10, as during engine braking of the motor car, braking torque then being transmitted from the shaft 11 through a slipping friction coupling 46 in parallel with the ratchet clutch 45 to the friction disc 24. The slip coupling comprises a frusto-conical friction lining 47' carried in a disc 48 splined on the hub 26 and biased by a spring 50 into engagement with a corresponding frusto-conical periphery 46, interrupted by slots 60, on the disc 36. In a modification, Fig. 5 (not shown), the frustoconical lining is mounted upon the disc 36 and engages a co-operating peripheral surface upon the disc 48. As shown, the engine shaft 10 of the car is fast with a casing 21 which can be connected by the disc 22 of an auxiliary clutch to a carrier 19 supporting pivoted masses 18, which when rotated fly radial outwards to engage a a cam surface upon a thrust plate 17 connected by a bearing 16 to an engaging plate 15 transmitting clutch-engaging force through springs 14 to a pressure plate 13 fast for rotation with the engine flywheel 12. On energization of a stationary solenoid 23, during a ratio shift, the auxiliary clutch disc 22 is withdrawn from engagement with the rotating clutch casing 21 and is brought to rest, together with the carrier 19, so that the masses 18 move radially inwards and disengage the main clutch 12, 13, 32. The driven clutch disc 24 carries a ratchet gear 52 having teeth 53 engaged, when the engine shaft 10 and flywheel 12 are at rest, by pivoted centrifugal pawls 54, so that the motor car engine can be started by towing. As soon as the engine starts, the pawls 54 are biased by centrifugal force to a position where they are clear of the ratchet teeth 53 on the gear 52, and guards 54a move outwards to cover the teeth. Shocks caused by engagement of the centrifugal pawls 54 with the teeth 53 when the motor car engine stops suddenly are thereby avoided. The ratchet clutch 45 comprises spring-biased clutch rollers 45a alternating with bearing rollers 45b.