Patent ID: 7595710

Claim:
A contact assembly for reciprocating between a stable closed position to allow current flow through the contact assembly and a stable open position to prevent current flow through the contact assembly, the assembly comprising: a base; a fixed contact mounted to the base; a contact arm; a pivot pin for pivotably mounting the contact arm to the base; a moveable contact mounted on the contact arm for movement between the stable closed position wherein the moveable contact is in contact with the fixed contact, and the stable open position wherein the moveable contact is spaced apart from the fixed contact; a spring exerting a spring force on the contact arm to bias the moveable contact toward the stable closed position of the contact assembly; a magnetic latch solenoid comprising: a magnetic armature; a permanent magnet in proximity to the armature when the armature is in a retracted position, the permanent magnet having a magnetic field exerting a latching force on the armature to maintain the armature in the retracted position; and a coil in proximity with the armature, the coil being adapted to exert a retracting force on the armature in excess of the spring force in a direction of the retracted position of the armature when electrical energy is applied to the coil in a first polarity, and to disrupt the magnetic field when electrical energy is applied to the coil in a second polarity to release the armature from the retracted position; and a wrist pin connecting the contact arm and the armature, the wrist pin being disposed in a clearance hole in at least one of the contact arm and the armature, permitting relative movement thereof; the retracted position of the armature resulting in the stable open position of the contact assembly.