Electrical switching apparatus such as a power circuit breaker, network protector or switch has a self-supporting operating mechanism module including a cage formed by a pair of side plates rigidly clamped in spaced relation by spacers. The cage supports all of the operating mechanism components including a helical compression close spring mounted fully between the side plates and coupled to a cam member through a rocker in a manner which maintains the forces longitudinal to the spring. The cam member has a charging cam with a charge profile for compressing the close spring and a close profile through which the spring drives the cam member to effect a controlled release of stored energy to close the contacts of the apparatus. The cam shaft is captured between bushings seated in non-circular openings in the side plates thereby eliminating the need for any fasteners. Likewise, other parts mounted between the side plates and joined by pins having enlarged heads retained by the side plates do not need retainers. Various shafts extending between the side plates have reduced diameter ends of progressive lengths for successive insertion in one side plate to aid in assembly of the operating mechanism.