Abstract: A tripping device comprises a coil frame, a coil, a plunger, a spring, and an anti-shock device. The coil is fixedly coupled to the coil frame and has a cylindrical channel extending therethrough. The plunger is reciprocatingly received within the cylindrical channel and the spring is structured to bias the plunger within the cylindrical channel. The anti-shock device includes at least one of a number of anti-shock devices structured to eliminate movement of the coil relative to the coil frame and a number of anti-shock devices structured to eliminate movement of the plunger relative to the cylindrical channel. An under-voltage release mechanism comprises a mounting bracket, a tripping device, and an angled support. The mounting bracket includes a first portion and a second portion. The angled support is fixedly coupled to the mounting bracket between the first and second portions and is structured to prevent flexing of the mounting bracket.

Abstract: A molded case circuit breaker is taught with a housing base and a primary cover disposed on the housing base. The primary cover has a recess therein for an auxiliary module which is disposed in the recess. A secondary cover is disposed on the primary cover for covering the recess when the auxiliary module is disposed therein. In order to secure the auxiliary module underneath the secondary cover in the recess of the primary cover, the module has deposed thereon a locking protrusion which is complimentary with a locking opening in the primary cover. The locking protrusion is flexible and has a longitudinal central bulge so that as the protrusion is pressed inwardly into the opening, the bulge causes the flexible protrusion to reduce diameter due to the presents of longitudinal slots therein until the bulge has passed the opening in which case it springs outwardly toward its normal position thus securing the protrusion in the base.