Miniature circuit breaker with improved longevity

A circuit breaker device has a chamber in which is disposed a single break contact system using low contact resistance material mounted on movable and stationary supports arranged in a loop configuration in order to direct arcs between the contacts through an arc chute into a remote portion of the chamber. A push-button is connected through a kinematic linkage which transfers motion using minimal frictional engagement to a movable contact to bring the movable contact into and out of engagement with a stationary contact and to latch the contacts in engagement during normal operation. A cantilevered current carrying bimetal transfers motion caused by I R heating of the bimetal to an ambient compensating bimetal connected to the latch mechanism. The kinematic linkage includes a latch surface which engages a rollable cylindrical reaction surface of the latch mechanism to cause the movable contact to come into engagement with the stationary contact upon depression of the push-button. Upon overload, the latch mechanism is displaced with the latch surface moving away from the reaction surface allowing return springs to return the push-button to its unactuated position and separate the contacts.