[i5] 3,649,784  Mar. 14,1972
A circuit breaker is disclosed having a fixed contact, a movable contact, a movable carrier mounting the movable contact, and a tripping mechanism for disconnecting the contact in response to overload currents. The carrier is spring biased, and mounted for pivotal movement between an unlatched position wherein the contacts are electrically disconnected, and a latched position wherein the contacts are selectively connectable. The tripping mechanism is in series electrical circuit with the fixed and movable contacts for releasably maintaining the carrier in the latched position under nonoverload current conditions, thereby enabling the series electrical circuit to be selectively completed, and for releasing the carrier to permit it to return to its unlatched position in response to overload current conditions, thereby interrupting the circuit connection between the fixed and movable contacts. The tripping mechanism includes a pivotal main latch selectively engageable with the carrier to maintain the carrier in the latched position, an auxiliary latch pivotal transversely relative to the main latch for selectively holding the main latch in a position to engage the carrier, and a bimetal movable in response to overload currents for pivoting the auxiliary latch which in turn releases the main latch enabling the latter to pivot, releasing the carrier and electrically disconnecting the fixed and movable contacts.
3 Claims, 12 Drawing Figures