MECANISMO APERFEICOADO DE ACIONAMENTO DE EMBREAGEM PARA USO EM ACIONAMENTOS POSITIVOS

A positive drive and an improved clutch actuating mechanism for use therein is disclosed. The positive drive has a housing (10) retaining a pair of spaced drive clutches (54 and 56) which lock a pair of axles (18 and 20), respectively, to housing (10) for one-to-one rotation. The clutches are moved from the disengaged to the engaged mode by axial movement of drive couplings (30 and 32) which include cam members (38 and 40) respectively. Input torque is transmitted from the housing to the cam members by means of a shaft (48) and the axial forces required to engage the clutches are transmitted from the shaft to the cam members through engagement of a shaft cam surface (49) and a ramp cam surface (51). In accordance with the invention, the engaging cam surfaces are defined by a common locus of generating lines (101-106) such that the cam surfaces are in surface-to-surface contact, rather than line contact or point contact, over the entire range of pivotal movement of the shaft, relative to the cam members.