Circuit breaker having shock-proof trip-actuating assembly

In combination with a circuit breaker having a housing of insulating material that contains a pair of contacts one of which is movable into make-circuit and break-circuit relationship with the other contact by a spring-powered operating mechanism that includes a toggle assembly and a latch component,

• a trip member pivotally mounted within said housing and adapted to engage and releasably capture said latch component when the operating mechanism is spring-loaded and thereby maintain the operating mechanism and contacts in make-circuit relationship, said trip member being actuable to release said latch component and permit the spring-loaded operating mechanism to rapidly separate the contacts and swing the movable contact to break-circuit position,
• means for actuating said trip member and tripping the circuit breaker in response to a current-overload condition, comprising;
• an elongated actuator reciprocally movable along a path and through a distance such that the end of said actuator strikes said trip member and releases said latch component when the actuator is moved from a dormant NO-TRIP position to a TRIP position,
• means responsive to a current-overload condition for rapidly moving the actuator from NO-TRIP to TRIP position,
• means mechanically locking the plunger in dormant NO-TRIP position,
• means for releasing said locking means in response to a current-overload condition and in synchronism with the actuation of the actuator-moving means so that the actuator is automatically motivated and initiates the tripping sequence within a predetermined period of time after the current-overload condition occurs,
• the actuator-moving means comprising a solenoid that has a wire coil and a reciprocally-movable magnetic core member and is mounted within the circuit breaker housing adjacent the trip member,
• the actuator comprises a longitudinally extending appendage of said solenoid core member,
• the solenoid is supported within the circuit breaker housing by a yoke of magnetic material that extends around the wire coil and core member of the solenoid,
• the yoke has side walls and a pair of end walls that are joined to one another and form a chassis, each of the end walls of the yoke-chassis having an aperture therein that effects a slip-fit with the plunger and opposite end of the solenoid core member and permit the plunger-core member component of the solenoid to move reciprocally between said TRIP and NO-TRIP positions and also rotate.
• the actuator-locking means comprises (a) a laterally-extending lobe of magnetic material on an exposed portion of the solenoid core member, (b) stop means integral with the yoke-chassis for engaging the magnetic lobe of the solenoid core member when the solenoid core member is in NO-TRIP position and then permitting passage of the lobe and reciprocal movement of the solenoid core member when the solenoid core member is rotated through a predetermined angle, and (c) magnetic pole means integral with the yoke-chassis for producing a magnetic field, when the solenoid is energized, which interacts with the magnetic lobe of the solenoid core member in a manner such that the solid core member and plunger are rotated through said predetermined angle and the lobe clears and slips past the stop means with concomitant release and reciprocal movement of the solenoid core member and actuator.