Abstract: A circuit breaker is disclosed having a toggle mechanism in which a desired overlap between the cam link and the sear pin is conveniently, and automatically, achieved. The toggle mechanism also exhibits a relatively small eccentricity, resulting in a circuit breaker which is significantly more sensitive to overcurrents than previous such circuit breakers.

Abstract: A new single pole circuit breaker, intended for use in a multipole circuit breaker, is disclosed. Among other distinctions, upon being tripped, a relatively large torque is imparted to the trip lever of the single pole circuit breaker. This is achieved by interacting the contact bar stop pin on the contact bar of the single pole circuit breaker with a camming surface on the trip lever. In addition, when pivotal motion is imparted to the trip lever by an external agent, the trip lever directly engages the toggle mechanism of the circuit breaker, to collapse the toggle mechanism and produce tripping. Moreover, the trip lever has a configuration which permits convenient pivotal mounting to a frame.