Abstract: A molded case circuit breaker wherein a movable contact arm (8) is operated between open and closed positions with a stationary contact (4b) by an operating mechanism which controls an overcenter toggle drive spring (12) and which is automatically openable upon sensing overload conditions by releasing a latched lever (10) for carrying the line of action of the drive spring (12) across the pivot (8a) of the movable contact arm (8). The current sensing trip means (16) for unlatching the latched lever (10) is formed of a shape memory effect alloy to provide a significant amount of travel of the latching end thereof in response to a narrow band of current thereby to insure release of the latch lever (10) without need for calibrating the breaker.

Abstract: An over-the-shoulder automotive safety seat belt system having a latch providing a tensionless comfort setting for the belt during use and having remotely operable thermostat metal means to release the latch and permit automatic belt retraction after use is shown to have an improved electrically operable latch release mechanism providing reliable latching and providing fast and reliable latch release operation at low power levels.

Abstract: An over-the-shoulder automotive safety seat belt system having a latch providing a tensionless comfort setting for the belt during use and having remotely operable thermostat metal means to release the latch and permit automatic belt retraction after use is shown to have an improved electrically operable latch release mechanism providing reliable latching and providing fast and reliable latch release operation at low power levels.

Abstract: A circuit breaker includes a fixed contact, a pivotable contact carrier having a movable contact for engagement with the fixed contact, a pivotable trip arm, a latch adapted to latch the trip arm, a thermostatic element adapted to engage the latch, and an overcenter spring coupled between the contact carrier and the trip arm. In the event of an overcurrent, the latch releases the trip arm, and the overcenter spring retracts the contact carrier, disengaging the contacts. An improved trip arm includes an integrally formed, perpendicularly extending lug which strikes the contact carrier, providing an impact force to disengage the contacts in the event of welding of contacts together.

Abstract: A secondary circuit breaker for a distribution transformer characterized by electrical inductive apparatus within an oil-filled housing, and circuit interrupter for controlling current flow through the transformer and comprising a releasable latch arm, trip means operable upon overload conditions to release the latch arm, a latch lever between the trip means and the latch arm and comprising the only operable part therebetween, and the latch lever having a cam surface for latching and unlatching the releasable arm.

Abstract: A circuit breaker suitable for use on both AC and DC circuits includes a magnetically permeable core surrounding a current carrying conductor of the circuit breaker. A bimetal member is thermally coupled to the core such that induction heating of the core due to overload AC current flowing through the conductor is operative to deflect the bimetal and actuate a trip device. The circuit breaker also includes a pair of braided copper shunts connected between the conductor and the bimetal such that resistive heating of the conductor due to overload DC current flow through the breaker will cause the bimetal to deflect and actuate a trip device. The bimetal is mechanically isolated from the conductor such that relative movement therebetween will not affect thermal calibration of the circuit breaker.

Abstract: A circuit breaker having a switch mechanism consisting basically of a pivotally mounted latch which is releasably mounted on a release member and which carries a pivotally mounted contact, and of a pivotally mounted manually operable element for operating the circuit breaker. A spring is connected to the manually operable element at a position offset with respect to the pivotal axis of the element and is arranged to apply a force to the pivotable latch at a position close to the pivotal axis of the latch. A latch lever interconnects the manually operable element and the pivotable latch and is connected to the manually operable element eccentrically with respect to the pivotal axis of the latter and is connected to the pivotable latch in a manner as to form the pivotal axis of the latter.

Abstract: A circuit protector comprising a case and a rocker or handle movable between "on" and "off" positions. A spring has one leg biased against the case and the other leg biased against the rocker for biasing the rocker to the "off" position. Within the case is a stationary contact and a movable contact carried by a movable contact blade. The rocker includes an extension which carries a pivotal latch lever and a slidable latch. The latch lever has a detent for restraining movement of the slidable latch. Further, the slidable latch includes a cam stop engaging a raised portion of the movable contact blade to keep the contacts engaged. A bimetal, on predetermined overload heating, engages the latch lever and pivots it away from the slidable latch, whereupon the detent is moved out of engagement with the slidable latch permitting the slidable latch to move upwardly under pressure of the movable contact blade and also permitting the rocker to be pivoted by the spring to the contacts "off" position.

Abstract: An electric switch having an actuator (24) normally manually operable to close and open a load circuit is provided with an electro-thermal device (42) of the coil (46) heated bimetal (43) type connected to external terminals (16, 17) adapted to be energized by a remote switch and power source to actuate the manual actuator (24) back to its open position.

Abstract: An electric circuit breaker including a U-shaped bimetal operably associated with a trip crossbar to effect rotation of the crossbar and subsequent opening of breaker contacts in response to heating of the bimetal to a predetermined temperature by the passage of an electrical current of a selected magnitude therethrough. The bimetal provides self-contained adjustment through the use of a calibration screw threaded into the lower leg of the bimetal which exerts force through an insulating member to the upper leg of the bimetal permitting ready calibration of the bimetal according to ampere rating of the particular circuit breaker.

Abstract: A current-responsive, resettable, violence-free low fault range vacuum-type switch interrupter is disclosed which is especially designed for series connection with a high fault range current limiting fuse (CLF) to achieve an improved, full range circuit protecting device adapted for use in padmounted, oil filled switch gear apparatus or the like. The resettable switch includes a spring-loaded, over center toggle motive assembly along with a current-responsive, temperature sensitive, bimetallic U-shaped latching element; in the event of a fault, the element deforms and releases the motive assembly to quickly open the vacuum contacts without the violence or oil contamination associated with fuse links. Manual opening of the contacts, and resetting thereof after either manual or fault-induced contact opening, is achieved through appropriate manipulation of an external, trip-free operating handle.

Abstract: An improved electrical circuit breaker which is so arranged that, by the deflection of a bimetal plate of approximately rectangular configuration having, at its opposite ends, electrical contacts contacting corresponding portions of terminal plates under a predetermined contact pressure, the engagement of the central portion of the bimetal plate and an engaging member is released so as to cause the bimetal plate to move in the direction normal to the direction of application of the contact pressure by spring force of a spring member through a holder member for cutting off electrical connection between the terminal plates.

Abstract: In a manual switch with thermal and magnetic release, the fixed pivots of a control member, of a latch, and of a transmission member coupled to the contacts, are disposed at the apices of a right-angled triangle, one side bounding the right angle being parallel to the direction of actuation of the control member and to the movement of the contacts, the other side bounding the right angle being placed in the vicinity of the control member.

Abstract: A circuit interrupter including a releasable latch restrained by a stamped metal rotatable cam having a latching surface in sliding contact with the latch member. The rotatable cam is inclined at an angle to the axis of rotation so as to cause only the smooth portion of the latching surface produced by the shearing action of the stamping process to contact the latch member. The rough portion of the latching surface produced by tearing action of the stamping process is not in contact with the latch member, thereby eliminating the need for a machining operation to provide a low friction contact surface with the latch member.

Abstract: A two pole circuit breaker is assembled in a case comprising two identical halves. Each case half contains one pole comprising like terminals and contacts. An actuating mechanism for both poles of the circuit breaker is mounted on the center line of the case so as to be clamped by the two case halves. The case halves also hold the external terminals and support the conductors and contacts of each pole of the circuit breaker. Bimetallic elements are secured to one of the terminals of each pole, bridging members containing contacts at opposite ends thereof, completing a circuit between the other of the terminals on each pole and the bimetal thereof when the contacts are in the closed condition. When an overload heats one or both of the bimetals, the bridging member is released, opening both contacts thereon and advancing a common trip bar of the operating mechanism to interrupt the circuit through the other pole. By pushing the manual operator inwardly, the contacts of both poles are reset.

Abstract: A molded case multi-pole circuit breaker is provided with a solid state trip unit constructed to automatically open the breaker responsive to predetermined fault current conditions. In addition, a bimetal actuated device sensitive to air temperature within the breaker housing is provided for automatically opening the breaker when air temperature within the housing exceeds a predetermined level.

Abstract: Circuit breaker having a trip arm which is released during tripping of the breaker under overcurrent conditions. One end of a contact opening arm is pivotally mounted on the trip arm. When the trip arm is released, the trip arm also contacts the other end of the contact opening arm forcing it against the contact carrier which supports the movable contact thereby opening the contacts.

Abstract: A multiple circuit thermal circuit breaker comprises a plurality of single circuit breakers which are contained in a housing. A single manually operable control is provided to effect resetting of all the circuit breakers and each circuit breaker includes a temperature sensing means through which the current flowing in the respective breaker flows, the temperature sensing means when the current exceeds a predetermined value acting to trip the respective circuit breaker. Linkage is provided between the circuit breakers so that when one is tripped by operation of its temperature sensing means the other circuit breakers will also be tripped.