Patent GB-649586-A (GB)
Title: Improvements in or relating to clutch mechanism
IPC: F16D41/07
Filed: 1947-12-08
Abstract: 649,586. Ratchet and claw clutches ; hydromechanical clutch combinations BORGWARNER CORPORATION. Dec. 8, 1947, No. 32301. Convention date; Dec.6, 1946. [Class 80(ii)] '[Also in Group XXIX]  An overrunning  clutch D, Figs. 4 and 5, comprises rocking wedges 62, arranged in transverse slots in a cage 60 between cylindrical driving and driven members 50, 21, and urged into jamming position by individual springs 63 enclosed in forked retainers 64, the cage 60, which forms a support bearing, between the cylindrical members 50. 21, being formed of slightly oval or other non-circular shape so as to be deformed on assembly to engage frictionally and provide drag on at least one, e.g. 50, of the members 50; 21, such drag serving to feed the cage a small step forward at each engagement of the clutch to expose different surfaces and distribute the wear. In Figs. 1 and 2, the overrun-clutch D is  .shown used in combination with a fluidcoupling B and a centrifugal positive clutch C, arranged between the engine crankshaft 20 of a motor-vehicle and a shaft 21 which drives the change-speed gear through a conventional friction clutch, shown in, part at 24a. The fluid-coupling has its impeller 22 and runner 23 permanently fast to the driving and driven shafts 20, 21 respectively, and in parallel with it are arranged in series, first the centrifugal positive clutch C and second the overrunclutch D, whereby the centrifugal positive clutch C provides a wholly mechanical forward drive introduced automatically by accelerator-release above a predetermined speed, whilst the overrun-clutch ensures that negative torque, for engine-braking, always passes only through the fluidcoupling. The centrifugal positive clutch C comprises a pawl 53, Fig. 2, guided radially on its driven member 20 and moving centrifugally outwards against a return-spring 58, to engage one of a number of slots 54 in a surrounding drive shell 55 fast on the driving shaft 20, the face 53b of the pawl being inclined so as to ratchet over the slots until the speed of the driving shell 55 is reduced to that of the driven member 50 by release of the accelerator-pedal, whereupon the pawl enters a slot to engage the clutch. A spring-loaded lateral plunger 57 applies friction drag to the pawl 53, the end of which is reduced at 53a to provide an additional resistance to inward movement so that the disengaging speed is less than that of engagement. The driven member 50 of the positive clutch C constitutes the outer driving member of the overrun-clutch D, the driven member of which is the driven shaft 21. The ariven shaft 21 is piloted in the driving shaft 20 in a ball-bearing 41, the inner race of which is retained on the shaft 24 by pegs 46 which are spring-pressed radially outwards to engage the chamfered inner surface of the bearing-race, so that the pegs are yieldingly moved inwards when the driven shaft 21 is withdrawn from the bearings. The Specification as open to inspection under Sect. 91 states that, in the overrunclutch D, during overrun, centrifugal force lifts the wedges clear of the inner driven member 21, thus avoiding rubbing wear thereon; and also that the change-speed gear driven by the clutch combination may be of the type providing semi-automatic shift by accelerator-manipulation. This subject-matter does not appear in the Specification as accepted.