Abstract: An operating mechanism controls and trips a separable contact structure arranged in a protected circuit. The mechanism includes a frame, a drive member pivotally coupled to the frame, a spring pivotally connecting the drive member to a drive connector, an upper link pivotally seated on the drive connector, a lower link member pivotally coupled to the drive connector, a crank member pivotally coupled to the lower link member for interfacing the separable contact structure, and a cradle member pivotally secured to the frame and pivotally securing the upper link. The cradle member is configured for being releasably engaged by a latch assembly, which is displaced upon occurrence of a predetermined condition in the circuit such as a trip condition. The mechanism is movable between a tripped position, a reset position, an off position, and an on position. Spacers are operatively positioned between movable members, and protrusions are operatively formed on the enclosure of the contact structure.

Abstract: A circuit breaker rotary contact assembly employs a common pivot between the rotor assembly and the rotary contact arm. A pair of off-center expansion springs directly engage the rotor at one end and engage the rotary contact arm via a linkage arrangement at an opposite end thereof.

Abstract: An air circuit breaker bell alarm accessory interacts with the circuit breaker closing system to allow automatic resetting of the bell alarm module upon resetting of the circuit breaker operating mechanism. A lockout slide extends between the bell alarm module support and the bell alarm reset slide to automatically reset the bell alarm module prior to closing of the circuit breaker contacts.

Abstract: An electrically conducting strap for use in a rotary circuit breaker cassette provides dual connectors to accommodate either an electronic or mechanical trip unit within the circuit breaker and electrical distribution system. The continuous, integral strap includes a first section including a fixed contact mounted thereon, a U-shaped second section, a third section having two apertures for connection to associated electrical equipment, and a fourth section having two apertures for connection to a line of a distribution system providing electrical power to a load. Thus, the circuit breaker has the advantage of reduced cost and increased ease of manufacturability since a common cassette is used.

Abstract: A circuit breaker operating handle charging torque compensating module includes an operating handle lever connecting between the operating handle and a support frame by means of an extension spring to maintain a uniform force exerted by the operating handle extension spring.

Abstract: An air circuit breaker ratcheting mechanism includes a ratchet and pawl whereby the closing springs charging gear is prevented from reverse rotation during the closing springs charging operation. Upon completion of the charging operation, the ratchet and pawl become disengaged from the charging gear to allow the closing springs to respond to a manual closing button depression. A holding prop within the ratcheting mechanism interacts with a roller bearing on the charging shaft to prevent reverse rotation of the charging shaft under the bias provided by the charged closing springs.

Abstract: The circuit breaker is characterized by separable contacts operable between a closed and an open position a contact arm having a latching surface and a latch arranged to engage the latching surface when the contacts are blown-open under short-circuit conditions. The arrangement of the latch allows for a positive lock under high magnitude short circuit levels while minimizing the force required by a mechanism to unlock the arm.

Abstract: An air circuit breaker bell alarm lock-out accessory interacts with the circuit breaker closing system to prevent charging of the circuit breaker closing spring until and unless the bell alarm module has been manually reset. A lockout slide on the bell alarm module support interacts with the circuit breaker closing spring operating link to prevent the recharging of the closing spring.

Abstract: A rotary contact circuit breaker having a venting arrangement to vent gasses operated by a short circuit interruption to a location substantially above the load strap of the breaker whereby electrical components are not damaged by the gasses and ionized gasses from different phases are conveyed in discrete channels for a period exceeding the period during which ionization is present.

Abstract: An air circuit breaker bell alarm accessory interacts with the circuit breaker contact position indicator to provide local and remote indication of the occurrence of a circuit interruption. A drive pin extending from the bottom of the accessory interacts with a slot on the contact position indicator lever to prevent release of the circuit breaker closing spring until the bell alarm accessory is manually reset.

Abstract: A circuit breaker ON/OFF contact position indicator employs a bell crank assembly interconnecting between the target indicator at the front of the circuit breaker enclosure and the circuit breaker contact closing shaft at the rear thereof to provide accurate real time indication of the ON/OFF condition of the circuit breaker contacts.

Abstract: A circuit breaker contact spring blocking arrangement is by-passed by means of a lock-out system that interacts between the circuit breaker contact spring closing shaft and the circuit breaker closing lock-out system when the circuit breaker contacts are in the OPEN condition.

Abstract: An air circuit breaker bell alarm unit allows selection of both bell alarm accessory lock-out facility along with automatic reset function. A plunger extending from the bottom of the bell alarm accessory interacts with the circuit breaker operating components to automatically reset the bell alarm pop-up target in the early stages of the closing of the circuit breaker contacts or to lock-out the closing of the circuit breaker contacts until the pop-up target is manually reset.

Abstract: An air circuit breaker bell alarm accessory interacts with the circuit breaker operating mechanism to provide local target indication as well as remote signal indication of the separation of the circuit breaker contacts. An indicator switch provides remote signal indication while a lock-out switch interacts with the accessory target to prevent re-closure of the circuit breaker contacts. One of the switches is selected having "normally open" contacts while the other switch is selected having "normally closed" contacts to reduce the amount of mechanical force required to simultaneously operate the indicator and lock-out switches.

Abstract: An air circuit breaker bell alarm accessory interacts with the circuit breaker contact position indicator to provide local and remote indication of the occurrence of a circuit interruption. A drive pin extending from the bottom of the accessory interacts with a slot on the contact position indicator lever to reset the bell alarm accessory when the circuit breaker contacts are in the process of being closed.

Abstract: A circuit breaker contact closing solenoid assembly within an air circuit breaker includes an upper drive link connecting between a lower drive link and the circuit breaker closing prop driver to release the closing prop driver post from the charging ratchet retainer post. Actuation of the circuit breaker closing solenoid rotates the upper and lower links to allow the charging ratchet to rotate and release the charged closing springs and drive the circuit breaker contacts to the CLOSED condition.

Abstract: An air circuit breaker ratcheting mechanism includes a ratchet and pawl whereby the closing springs charging gear is prevented from reverse rotation during the closing springs charging operation. Upon completion of the charging operation, the ratchet and pawl become disengaged from the charging gear to allow the closing springs to respond to a manual closing, command. An operating handle pivot assembly allows a molded plastic handle operator to be employed and the ratcheting mechanism is arranged for modular assembly during the circuit breaker manufacturing process as well as motor to manual charge conversion one site.

Abstract: A remote actuator for an enclosed molded case circuit breaker utilizes an actuator cable connection with the circuit breaker operating handle in a "pull-pull" arrangement. The cable is arranged in an endless loop between the actuator handle and the circuit breaker operating handle. Moving the actuator handle in a first direction pulls the circuit breaker operating handle to its ON position while moving the actuator handle in an opposite direction pulls the circuit breaker operating handle to its OFF position.

Abstract: An industrial rated molded case circuit breaker fitted with an exhaust arc gas manifold arranged over ventilation slots of the circuit breaker and disposed at a line end thereof to redirect the arc exhaust gases exiting the ventilation slots. The exhaust arc gas manifold is fixedly attached to the circuit breaker to prevent an electric fault from occurring between the different phases of a multi-phase electric power distribution system connected to the line end of the circuit breaker. An electric fault is further prevented between the exiting arc gases and the line terminals attached to the circuit breaker thereof.