Abstract: A rotatable trip test assembly unit for molded case circuit breakers consists of a unitary plastic part that cooperates with the internal structure of the circuit breaker cover to provide return spring bias to the trip test button. The trip test assembly unit rotates about a pivot and strikes the circuit breaker trip bar to thereby articulate the circuit breaker operating mechanism and separate the circuit breaker contacts. The interaction between a cam-follower on the assembly unit and a cam-shaped piece within the circuit breaker cover automatically returns the trip test button to its initial position upon release.

Abstract: A compact current limiting circuit breaker with an electronic trip unit arranged within the circuit breaker cover and current transformers in the circuit breaker case incorporates reinforcement ribs in the cover to provide added strength. The cover also includes line terminal plugs that removably attach to the cover for preventing inadvertent access to the circuit breaker line terminals when the circuit breaker is energized. Protrusions formed on the bottom surface of the circuit breaker cover under the trip unit provide further strength while cooperating with flexible pads on the top of the current transformers to automatically compensate for manufacturing tolerances.

Abstract: A circuit breaker operating mechanism employs a multi-latch arrangement for controlling the automatic opening of the circuit breaker contacts upon predetermined overcurrent conditions. The multi-latch assembly is robotically assembled to the operating mechanism and is retained thereon by means of a retainer tab. The circuit breaker case and cover contain integrally formed steps which receive extensions formed on the operating mechanism assembly. The operating mechanism assembly becomes wedged between the circuit breaker cover and case when the cover is later fastened to the case.

Abstract: An industrial rated molded case circuit breaker having an electronic trip circuit contained within the circuit breaker enclosure includes a reset spring in cooperation with the circuit breaker latch spring to insure manual reset of circuit breaker after an automatic trip function. The reset spring allows the circuit breaker latch assembly to be manually reset upon minimum travel of the circuit breaker operating handle due to internal circuit breaker component space restrictions. The circuit breaker latch assembly is robotically loaded to the operating mechanism which is then attached to the circuit breaker case by an automated fastening process.

Abstract: A circuit breaker operating mechanism for automated assembly finds application within circuit breakers of different ampere ratings. The circuit breaker contacts are opened and closed by means of a roller connected to the circuit breaker operating handle through a cradle link and a cam arranged on the movable contact carrier. The operating springs, cradle and latch are first assembled to the operating mechanism prior to assembly of the operating mechanism within the breaker housing.

Abstract: An industrial rated molded case circuit breaker having an electronic trip circuit contained within the circuit breaker enclosure includes a reset spring in cooperation with the circuit breaker latch spring to insure manual reset of circuit breaker after an automatic trip function. The reset spring allows the circuit breaker latch assembly to be manually reset upon minimum travel of the circuit breaker operating handle due to internal circuit breaker component space restrictions. The circuit breaker latch assembly is robotically loaded to the operating mechanism which is then attached to the circuit breaker case by an automated fastening process.

Abstract: A molded case circuit breaker crossbar assembly allows the movable contact carrier, contact spring and contact carrier operating cam to be preassembled prior to insertion within the circuit breaker case. The crossbar is fabricated from a plastic molding composition having slots thereon for supporting the movable contact carrier and for retaining the charged contact operating spring. The contact carrier operating cam engages a roller carried by the operating mechanism link to couple the crossbar assembly to the circuit breaker operating mechanism.

Abstract: A circuit breaker operating mechanism for automated assembly finds application within circuit breakers of different ampere ratings. The circuit breaker contacts are opened and closed by means of a roller connected to the circuit breaker operating handle through a cradle link and a cam arranged on the movable contact carrier. The operating springs, cradle and latch are first assembled to the operating mechanism prior to assembly of the operating mechanism within the breaker housing.

Abstract: A molded case circuit breaker crossbar assembly allows the movable contact carrier, contact spring and contact carrier operating cam to be preassembled prior to insertion within the circuit breaker case. The crossbar is fabricated from a plastic molding composition having means thereon for supporting the movable contact carrier and for retaining the charged contact operating spring. The contact carrier operating cam engages a roller carried by the operating mechanism link to couple the crossbar assembly to the circuit breaker operating mechanism.