GB863501A - Improvements relating to change-speed gear clutch devices - Google Patents

Abstract

863,501. Friction clutches. DAIMLERBENZ A.G. March 25, 1959 [March 28, 1958], No. 10369/59. Addition to 829,052. Class 80 (2). Engagement of frusto-conical friction surfaces on synchronizing rings 20, 21 with co-operating surfaces 25 on a hub 13 axially slidable to clutch one or other of gears 11, 12 to a shaft 10, as described in the parent Specification wherein radially inwardly projecting cam studs 16 on the slidable hub interdigitate with radially outwardly projecting similarly shaped cam studs 17 on the shaft and co-operating sinusoidal surfaces 22 between the gears and the rings balk completion of clutch engagement until synchronization has been achieved, is modified by mounting an auxiliary ring 27 having a frustoconical friction surface 32 within each of the synchronizing rings. The auxiliary rings 27 are connected by pins 28 passing through recesses 26 in a flange 15 of the hub 14, springs 29 between the studs and the pins biasing the auxiliary rings to turn relatively thereto, The size of the recesses 26 in the hub flange 15 is so chosen as to allow a limited rotation in this sense. The auxiliary rings 27 are formed with inwardly projecting cams 33, 33<SP>1</SP>, Fig. 3, which co-operate with radially outwardly projecting cams 34, 34<SP>1</SP> on the shaft 10. In the position shown in Fig. 3, with the control hub 13 in its central, neutral position and both clutches disengaged, the cam stops 33, 16, 33<SP>1</SP> on the first ring 27, the hub flange 15 and the secondary ring 27, respectively, are aligned, and the cam stops are interengaged by surfaces parallel to the main axis of the clutches. When the control hub 13 is slidden e.g. leftwards, the cam studs 16 on the hub flange 15 move to the position shown dotted in Fig. 3, so that their surfaces 19 co-operate and, as torque is transmitted from the gear 11 through the friction ring 20 to the sleeve 13 and thence through the coacting cam studs 16, 19 to the shaft 10, the reaction tends to slide the hub 13 leftwards to complete engagement of the clutch. At the same time, the two auxiliary rings 27 have also been slidden leftwards, so that the cam studs 33, 331 therein take up the positions also shown dotted in Fig. 3. Under these conditions, the springs 29 have been able to turn the auxiliary rings 27 relatively to the hub flange 15, so that in the direction of rotation considered, the studs 33 coact through their surfaces 35 with the cam studs 34 on the shaft. Accordingly, on a reversal of torque, with the shaft 10 now driving the gear 11 instead of vice versa, torque is transmitted from the shaft 10 through the studs 34 to the studs 33 on the auxiliary rings 27, and thence through the frusto-conical friction surface 31 to the synchronizing ring 20, and the sinusoidal balking surfaces 22 connecting to the gear 11, so that any noise or relative rotation between the parts on change of direction of torque transmission is prevented. In a modification, Fig. 4 (not shown), the hub flange is provided with oppositely directed pairs of interconnected recesses for the springs 29 so that the springs can be assembled to lie tangentially in either direction relatively to the hub, and the recesses 26 are made of such size that they are equal in dimensions considered in the rotary sense to the remaining segments of the hub flange on which the cam studs 16 are formed. The hub 13 may be provided with spring-bias detents, Fig. 5 (not shown), to co-operate with a pair of circum. ferential grooves in the periphery of the shaft 10 and hold the selected clutch in engagement.