Patent GB-654591-A (GB)
Title: Improvements in or relating to a torque transmitting coupling
IPC: F16H3/091
Filed: 1948-04-16
Abstract: 654,591. Change-speed gearing; friction and positive clutches. WEMP, E. E. April 16, 1948, No. 10559. [Class 80(ii)] Movement of a double claw clutch member 46, Fig. 1, from one position of engagement to the other is balked in two stages by the shoulders of projections and cut-aways 63, 64, Fig. 6, formed on axial fingers 57 passing through circumferential gaps in the operative flange 47 of the member 46 and connecting together frictional synchronizing cones 56, 59 co-acting with coned surfaces on the other claw clutch members 25, 32. The member 56, 59 has slight axial play and is entrained frictionally by a spring ring 60 on the member 46 to initiate its engagement in either direction. As shown the clutch, assembly is incorporated in a motor vehicle changespeed gear, which may be as described in U.S. Specification 2,518,734, following a main centrifugal friction clutch and comprising an input shaft 15 on which the member 46 is slidably splined, a layshaft 27 carrying a gear cluster 28, 29 fast therewith, gears 23, 30 rotatable on the shaft 15 and in constant mesh with the gears 28, 29 and a synchromesh clutch connection between the gear 30 and an output shaft 21, there being a further gear 41 on the layshaft which may be coupled to the shaft 21. The gears 23, 30 carry the clutch elements 25, 32 so that a countershaft reduced or a direct drive ensues when the member 46 is engaged with one or other element, with the gear 30 and shaft 21 clutched together. The main clutch comprises a driven disc 11 clamped between a flywheel 1 and presser plate 9, when the vehicle engine is rotating above idling speed, by centrifugal weights 5 acting through struts 10 on the plate 9 against retracting springs 16. An independent clutch control thrust bearing 8 is provided. When the member 46 is moved out of engagement with the member 25 the member 59 is brought into engagement with the member 32 and consequently lags behind the flange 47 rotationally, so that its advance is blocked by the projection 63. However, the accelerator release initially necessary to unload the torque between the members 46, 25 ultimately causes the member 59 rotationally to lead the flange 47 which advances further but is again blocked, this time by the shoulder 65 of the cut-away 64, until accelerator depression again causes the member 59 to lag when the member 46 is free to pass into engagement with the member 32. On return movement of the member 46 there is normally only single blocking, between the flange 47 and the shoulder 66 of the cut-away 64, the member 5, 7 tending to lead the flange 47 due to vehicle inertia until accelerator depression speeds the engine sufficiently to reverse the direction of reaction between the member and flange. The member 46 is slidable on straight splines, but has right- and lefthanded helical engagement with the members 32, 25 to facilitate meshing. The operative shoulders of the parts 63, 64 may be angled as shown to allow changes to be forced when the main clutch is disengaged. In a modification, disc synchronizing means 81, 82, Fig. 15, are used for the direct drive connection, the corresponding blocking shoulders 65<SP>1</SP>, 65a being less angled than the shoulder 66a controlling the countershaft drive connection, the synchronizing means for which comprises the separate coned ends of the various axial fingers 57a, all co-acting with a bronze or other coned ring 85 fitted, preferably by pressing, on an axial extension of the respective gear.