Electromagnetic clutch with two stage torque buildup

Abstract From the Canadian patent

Abstract of the Disclosure, An electromagnetic clutch or brake of the type having a clutch inner body with inner and outer pole faces drawn into engagement with an armature in order to establish driving engagement of the clutch. A two stage buildup of the torque is produced by an offsetting bias of the inner body pole faces by a nonmagnetic resilient ring separating the pole faces and a shunt washer of a ferromagnetic material which serves to successively draw the pole faces into engagement with the armature by varying the reluctance through the inner and outer poles as the inner body is drawn into engagement. The resulting two stage torque buildup slows the engagement time of the clutch to …