| 摘要 |
1,185,043. Ratchet clutches. HARRY FERGUSON RESEARCH Ltd. 4 May, 1967 [7 May, 1966], No. 20317/66. Heading F2C. In a ratchet clutch assembly a pair of cam plates are arranged to separate on relative rotation in one direction, first and second clutches have elements connected to the cam plates and co-operating elements connected to the driving and driven members, the clutches being engageable on separation of the cam plates, and restraining means prevent rotation of one of the cam plates in one direction. As shown balls 18 engage cam grooves 19 in plates 16, 17 which are coupled through disc clutches 14, 15 with the flanges 12, 13 of driving and driven shafts 10, 11, the clutches normally being lightly engaged by loading springs 21 housed between the cam plates 16, 17. The plate 17 is connected by a ring 23 to one element of an auxiliary oneway clutch 20. As viewed from the left counterclockwise rotation of drive shaft 10 causes separation of cam plates 16, 17 to fully engage clutches 14, 15 and drive the output shaft 11. The arrangement permits over-running of the shaft 11. With reverse clockwise drive, plates 16, 17 are not forced apart and the lightly engaged clutches 14, 15 transmit drive between shafts 10, 11. Clutch 20 operates to prevent clockwise rotation of plate 17 so that clutch 15 may slip to permit over-running of shaft 11. In this condition shaft 10 may also over-run shaft 11. Modifications (not shown) include:- (a) the provision of wedge surfaces (25, 26) between cam plate 17 and clutch 20 to allow shaft 11 to be rotated clockwise with minimum effort while a counter-clockwise torque is applied to shaft 10, Figs. 4-6; (b) the provision of screw stops (27) to limit axial movement of cam plate 17 to the left to prevent locking of clutch 14, Figs. 7-9; (c) the connection also of cam plate 16 to a brake or one-way clutch (29) to allow both shafts 10, 11 to over-run in either direction, Figs. 10-12; (d) the substitution of a one-way sprag clutch (30) for friction clutch 14, thus rendering stops (27) unnecessary, Figs. 13, 14. The clutch assembly may be incorporated in a limited slip differential for a motor vehicle or in a workpiece feed mechanism for a pressing or punching machine. |
