Molded-case circuit breaker having improved overcurrent releasable latch

Claim 1

A molded case circuit breaker having a stationary contact, an elongated movable contact member supported on a pivot between its ends, said elongated movable contact member having a contact at one end engageable with and disengageable from said stationary contact, and having an actuator pivoted at its opposite end and having an overcurrent releasable latch normally restraining said actuator, and a pivoted handle and a link connected to said handle forming a toggle for operating said actuator and for thereby operating said elongated movable contact member to close the contacts, said overcurrent releasable latch being carried by and movable with said elongated movable contact member, said overcurrent releasable latch including a current-responsive bimetal, a magnetic pole structure adjaCent said bimetal, an armature pivoted at one end on said pole structure and engaging said actuator at the other to thereby latch said actuator, and resilient means reacting between said contact member and said armature for biasing said armature into an actuator-latching position, said resilient means having a low profile in the direction of movement of hot arc-generated gasses when said circuit breaker opens whereby the exposure of said resilient means to said gasses is minimized.