Lightweight electromagnetic clutch with shock absorber

Claim 1

An electromagnetic clucth for establishing drive between first and second clutch members comprising: a ferromagnetic inner body having a radial face portion drivingly connected to one of said members; a ferromagnetic armature drivingly connected to the other of said members positioned adjacent said inner body and having a radial face opposite said inner body radial face; means mounting said armature and inner body enabling relative axial movement to bring said radial faces into and out of driving engagement; return spring means urging said inner body and armature out of driving engagement; electromagnetic coil means positioned to cause said inner body and armature to be drawn into driving engagement upon energization; torque booster means including a ball plate element disposed adjacent said armature and having a radial face opposite a radial face of said armature, and a plurality of balls disposed in corresponding conical pockets formed in each of said radial faces of said ball plate element and said armature whereby torque is transmitted through said balls between said armature and said clutch element, and the driving engagement force between said armature and inner body radial face portion is thereby increased by the action of said balls; a coupling plate axially spaced from said ball plate element and connected to said other member; shock absorber means joined to said coupling plate and ball plate element and at least partially filling the axial space therebetween; whereby said shock absorber means accommodates relative angular and axial movement between said first and second clutch elements, to reduce axial shock forces generated by said torque booster means.