Patent GB-1129235-A (GB)
Title: Clutch
IPC: F16D41/04
Filed: 1967-06-05
Abstract: 1,129,235. Ratchet clutches. DANA, CORP. 5 June, 1967 [17 June, 1966], No. 25935/67. Heading F2C. A free-wheel clutch mounted between a driving shaft and a pulley, or, as shown, between the driving axle 10 and the front wheel hub 16  of a four-wheel-drive motor vehicle,  allows automatic take-up of drive  in either direction and overrunning  in either direction, and includes a  manual hub lock 159 which over-  rides the automatic means for  locked four-wheel-drive. The clutch  comprises a driving inner race 50  splined to the axle 10, and provided  with camming grooves (78), Fig. 5 (not shown), co-operating with rollers 74 carried in a cage 90 and engaging the inner grooved surface of an outer driven race 46 splined to the wheel hub 16. Each groove (78) comprises a central groove 76 and a groove (80), (81) on either side thereof. When the rollers are in grooves 76, the hub may overrun the axle, but on movement into either groove (80) or (81) the rollers contact the inner surface of the outer race. A garter spring 84 urges the rollers 74 into contact with the inner race. The inner flared end 95 of the cage 90 frictionally carries a compressed split ring 108 held against rotation by engagement of at least one axially extending tang thereon with a slot in a ring 96 fast with the non-rotary axle journal, so that the split ring acts as a light friction brake on the cage. Thus, with the manual means 159 disengaged, on rotation of shaft 10 relative to hub 16, the split ring 108 acts to inhibit rotation of the cage, and the rollers 74 are urged from grooves 76 into the respective grooves (80)' or (81) to transmit drive with frictional slipping between the cage and split ring. On occurrence of overrunning of hub 16, rollers 74 are urged back into grooves 76 by the outer race against the frictional restraint imposed by the split ring 108 until such overrunning ceases, when drive is again taken-up. Manual locking means.-The manual locking means comprises a knob 158, freely mounted on a casing 124 fast with the outer race 46, carrying a cam 152 surrounded by a substantially rectangular split friction ring 148, the free ends of which abut a stop 190 also fast with the casing 124. Rotation of the cam 152 through 135 degrees expands the split ring 148 into contact with a friction ring 156 formed with a pair of slots 147 in which engage a pair of axially extending tangs 144 integral with the cage 90, so that the cage 90 is frictionally connected to the driven outer race 46. The frictional connection between the cage 90 and the outer race 46 is operative to override the frictional restraint on the cage against rotation relative to the journal 12. Thus, with the manual means 159 engaged, on rotation of shaft 10 relative to hub 16, the split ring 108 again acts to inhibit rotation of the cage, and the rollers are urged from grooves 76 to the respective grooves (80) or (81) to transmit drive. If, however, the hub 16 attempts to overrun, the cage will move with the hub since it is frictionally connected thereto and the rollers 74 are moved from, for example, the grooves (80) into the grooves (81), via grooves 76, thereby again placing the inner and outer races in engaged relationship. The outer race 46 is retained axially on the hub 16 by a snap ring 60 in a groove 62, the left-hand side of which is angled so that the snap ring is cammed radially inwards when the race is forced axially leftwards for removal, e.g. by a screw driver placed in groove 138 in the race.