Multi pole latch system having means to defeat single pole latching

Claim 1

A multi-pole circuit breaker including first, second, and third mechanisms, each comprising associated contact operating means, latch means and overload trip means; said operating means including a main spring means to provide contact operating power and contact pressure, and a latchable cradle movable by said spring means from a normally latched position wherein said operating means is effective for contact closing to a tripped position wherein said operating means is ineffective for contact closing when said cradle is released; said latch means including a latch unit normally maintaining the cradle of its associated operating means in its said latched position; said overload trip means when subjected to predetermined current overload conditions operating its associated latch means to release the cradle of its associated operating mechanism; common trip bar means for operating and for being operated by said latch units; each of said latch units being connected to the cradle of its associated operating means such that after releasing the last recited cradle the force of its associated spring means is transmitted through this last recited cradle and its associated latch unit to operate said trip bar means which in turn operates the other latch units to release their associated cradles; each of said mechanisms also including link means to prevent contact closing if all of the cradles are not in their said latched positions; said link means extending between the cradle and the latch unit of its associated mechanism; each of said link means being operatively positioned for actuation by the spring means of its associated mechanism acting through its associated cradle after an unsuccessful attempt has been made to latch its associated cradle; each of said link means upon actuation thereof operating its associated latch unit which in turn operates said trip bar means to operate the other latch units to release their associated cradles.