Patent ID: 6864450

Claim:
A circuit breaker movable between an OFF condition and an ON condition, the circuit breaker comprising: a housing; a set of separable contacts disposed on the housing; an operating mechanism that is disposed on the housing and is operable to move the contacts between a disconnected position and a connected position when activated, the operating mechanism including a movable structure that is movably disposed on the housing and is movable between a first position corresponding with the OFF condition of the circuit breaker and a second position corresponding with the ON condition of the circuit breaker; a trip unit that is responsive to current through the separable contacts for activating the operating mechanism; a switch for providing an input to the trip unit, the switch being switchable between a first condition corresponding with the OFF condition and a second condition that corresponds with the ON condition; a delay mechanism for delaying movement of the switch from the first condition to the second condition for a given period of time after a circuit breaker has moved from the OFF condition to the ON condition; the delay mechanism including an inertia member, a first spring, and a second spring; the inertia member being movable between an initial position corresponding with the OFF condition of the circuit breaker and a terminal position corresponding with the ON condition of the circuit breaker, the inertia member in the initial position maintaining the switch in the first condition, the inertia member in the terminal position permitting movement of the switch to the second condition; the first spring extending between the inertia member and the housing and biasing the inertia member toward the terminal position; the second spring extending between the movable structure and the inertia member when the movable structure is in the first position, the second spring biasing the inertia member toward the initial position and overcoming the bias of the first spring to retain the inertia member in the initial position when the movable structure is in the first position; the bias of the first and second springs being equal and retaining the inertia member in a state of equipoise at the initial position when the movable structure is in an intermediate position between the first and second positions; and the bias of the first spring overcoming any bias of the second spring and biasing the inertia member toward the terminal position when the movable structure is in substantially any of the second position and a location disposed between the intermediate and second positions.