GB786828A - Improvements relating to synchronizing clutch devices - Google Patents

Abstract

786,828. Positive clutches. DAIMLERBENZ AKT.-GES. Nov. 22, 1955 [Nov. 23, 1954], No. 33438/55. Class 80 (2). In a claw clutch combination wherein an internally-toothed sleeve 18 slidably keyed on a hub 15 is engageable with claw teeth 13 or 14 on wheels 10 or 11 to couple one or other wheel to the driven shaft 12 of a motor vehicle changespeed gear, and synchronizing rings 19 provided with baulking teeth 21 are coupled to the hub 15 and engage conical friction surfaces on rings 25 coupled to the wheels 10, 11, the friction rings 25 are coupled to their respective wheels 10, 11 through springs allowing limited relative rotation. To provide the spring connection, dogs 29 on the rings 25 engage between dogs on the wheels 10, 11 with angular clearance and springs, Fig. 2 (not shown), hold the dogs 29 in a central position. Three grooves 40, Fig. 3, in the hub 15 house slidable pieces 37 connected by spring-loaded balls 38 with the slidable sleeve 18, the pieces 37 engaging projections 41 on the synchronizing rings 19. The projections 41 have angular clearance in the grooves 40 and preferably this clearance, and the clearance for the dogs 29, correspond to half the pitch of the teeth 13, 17 and 21. If the sleeve 18 is moved to clutch the hub 15 to the rotating wheel 10, the rings 19, 25 are first pressed together by the pieces 37 and ball connections 38 and the ring 19 is frictionally rotated relatively to the hub 15 to take up the clearance in the grooves 40, this rotation causing the teeth 21 to baulk further axial movement of the teeth 17, i.e. of the sleeve 18. When the shaft 12 reaches the speed of the wheel 10, the torque between the ring 19 and hub 15 is reduced so that under axial pressure on the sleeve 18 the pointed teeth 17 turn the teeth 21 out of baulking position. If the friction between the rings 19, 25 is too great to allow relative rotation under this axial pressure, the springs locating the dogs 29 yield to allow both rings 19 and 25 to turn relatively to the wheel 10 until the teeth 17 can move through the teeth 21 and engage the claw teeth 13. The ring 25 is subsequently returned to its central position by the aforementioned springs, which may be associated with stops to limit their extension substantially beyond a centre position and so prevent oscillation of the ring 25.