Improvements in trip cross bar and trip armature assembly for a circuit breaker

A circuit breaker for interrupting the flow of current upon the detection of excess current or temperature is provided which comprises a housing, a trip armature plate (53), a trip armature frame (55), and a bias spring (73). The trip armature plate has at least two pivot tabs (57,69) extending laterally on opposite edges that are inserted into a pivot elongated slot (71), which is located at an open end of the trip armature frame, and a pivot aperture (63), which is located at the opposite end of the trip armature frame, respectively. A bias spring is used for securing the pivot tabs into the pivot elongated slot and the pivot aperture, and for urging the trip armature plate pivotably outwardly about the pivot tabs away from the trip armature frame. The circuit breaker also comprises a trip cross bar having at least two fingers that are used to engage optional circuit breaker accessories and that are located asymmetrically to allow the interchangeability of the accessories. During top down assembly, the trip cross bar is the last component that is assembled into the circuit breaker in order to allow the easy installation of other components, including the trip armature frame and trip armature plate.