Abstract: A modular crossbar arrangement for molded case circuit breakers allows a plurality of contact arm assemblies to be interconnected from a single modular unit. To provide increased acceleration to the movable contact arms a contact arm accelerator lever interfaces with the contact arm and crossbar assembly. To promote further acceleration of the movable contact arms to their closed positions, the movable contact arms in a multi-pole circuit breaker are staggered with respect to their rotational alignment within each pole on the crossbar assembly.

Abstract: A molded case circuit breaker is provided with a two piece cradle assembly having a cradle portion and a heat-treated portion. The heat-treated portion forms the latch and reset surfaces. The cradle portion is integrally formed from a pair of spaced apart cradle-shaped arms joined together by a connecting portion. The heat treated portion is securely fastened to the connecting portion to form the two piece cradle assembly. A hold down slidably carries a handle barrier with respect to the cover and closes a centrally located aperture in the cover for all handle positions. The handle barrier prevents arc products resulting from a separation of the main contacts from escaping through the centrally located aperture in the cover. Stops are provided in one or both directions to prevent misalignment of the handle barrier with respect to the operating handle. A cover interlock is also provided to prevent the cover from being removed when the circuit breaker is in an "on" position.

Abstract: The circuit breaker is formed by two adjoined standard multipole molded cases, resin being cold-cast between the opposite side walls, comprising reliefs, of the two cases in order to provide fixing. A spacer, secured by bolts to the side walls of the two cases, defines their distance apart and can be used to cooperate with a racking cam when the circuit breaker is drawn into a fixed frame. The circuit breaker comprises an electronic trip device, an operating mechanism and an operating bar of the poles common to all the poles. At least two adjacent poles are twinned, that is to say eletrically connected in parallel.

Abstract: A multiple circuit breaker system wherein each single pole breaker within the multiple breaker system have very similar structure and dimensions, except that at least one of the breakers (e.g. the one which is connected to a floating neutral pole) has an additional articulation which the other breakers do not have. This additional articulation, and the associated spring action, provide extended contact time.

Abstract: Warping and twisting of the armature of a polyphase alternating current air break contactor is reduced by mounting the operating coil near the middle of the armature. A polyphase alternating current air break contactor has a frame, an armature having two ends, the ends being rotatably mounted within the frame so that the armature may rotate within the frame, at least three movable contacts and at least three stationary contacts forming a contact pair of each phase of the polyphase alternating current, and the contactor has an operating coil for the armature mounted in the frame substantially midway between the two ends of the armature.

Abstract: A multi-pole circuit interrupter having a first pole unit provided with an operating mechanism and a second pole unit provided with no operating mechanism. Each of the pole units comprises a movable contact, a stationary contact, and a contact arm assembly for supporting the movable contact of the respective pole unit including a first contact arm and a second contact arm pivotally supported by a common pin. The first contact arm in the first pole unit have an elongated guide hole extending in a direction of movement of the movable contact and is directly connected to the operating mechanism. The second contact arm has an elongated hole extending substantially in a longitudinal direction thereof. A spring-biased sliding pin extends through the elongated hole and the guide hole.

Abstract: A circuit breaker has a metal frame (10) disposed on a base of a housing. A trip-bar (6) made of molded plastic of like material is rotatably held on the frame (10) by insertion of a trip-bar pin (15) into a center through-hole provided on the trip-bar, and pinchers (14,14) of the trip-bar (6) pinch the trip-bar pin by elasticity of the plastic material to hold the same in place with very little lateral play.

Abstract: In a high voltage circuit interrupter switch or recloser a single multi-function control actuator is connected to a trip bar for tripping contact operating linkage to effect opening of one or more movable contacts. The control actuator includes a spring biased crank member and a toggle linkage operably associated to permit resetting of the control actuator to its initial position upon effecting movement of the contact operating linkage. The recloser has a switch for energizing a closing solenoid to reclose the interrupter contact. A movable catch is associated with switch operating linkage and is operably connected to the control actuator whereby the control actuator may effect energization of the solenoid to close the interrupter contacts. The control actuator is also connected to a lockout linkage for effecting lockout of the contact operating linkage upon receipt of a control signal when a predetermined number of circuit interruptions have been performed in a predetermined time period.

Abstract: A circuit breaker for high-speed current-limiting breaking of a three-phase current in the event of a short-circuit condition. The breaker has three pairs of fixed and movable contactors, the latter being arranged for pivoting movement on a common shaft. The center movable contactor is biased against an opposing holder, such that in the event of a short-circuit, the bias is overcome and the movable contactors separate in unison from the fixed contactors.

Abstract: A circuit breaker having a plurality of breaker units, in each of which a movable contact of a movable contactor is separated from and engaged with a fixed contact of a fixed contactor from the exterior of a breaker housing by a manual contact opening and closing mechanism which is made operative to close the contacts normally with a tripping link retained as locked to the mechanism and inoperative with the link released from the mechanism by a tripping means responsive to an excess current. The tripping link is operatively interconnected to those in other units through a single coupling rod to cooperate simultaneously with the releasing by the tripping means in either one of the units.

Abstract: A multipolar type circuit breaker has a plurality of breaker element assemblies corresponding to AC source pole number. Each assembly comprises a contact operating mechanism for ON and OFF operations of a movable contactor connected to a load side terminal with respect to a fixed contactor connected to a current source side terminal. A trip mechanism forms an electric current path between the movable contactor and the load side terminal an interlinks with the contact operating mechanism for releasing its normal ON position latch with respect to the movable contactor upon incoming of a excessive curent to arbitrarity trip ON state. The assemblies are housed in a single housing in a mutually parallel and aligning relation. The contact operating mechanisms in all assemblies are operated by a single handle extending transversely to them within the housing.

Abstract: A circuit breaker having stationary contactors provided for all of the poles thereof. Movable contactors are provided for all of the poles in correspondence to the stationary contactors. Stationary contacts are provided on the end portions of stationary contactors and movable contacts are disposed on the end portions of the movable contactors. The movable contactors are movable from the stationary contactors by electromagnetic force to open respective circuits before the circuit breaker is opened by an overcurrent tripping device when large current such as short-circuit current flows. Holders adapted to hold the movable contactors of all of the poles are mounted on a common rotatable insulating rod, one of the holders being provided with a latch which is turnable around a rod provided on the holder. A slot is normally engaged with the latch, and when disengaged from the latch, a rod can be turned by the holder.

Abstract: Both undervoltage and shunt trip auxiliary feature modules, adapted to be mounted side-by-side with one or more circuit breaker modules include an electromagnetic trip device having a trip actuator which is biased toward tripping position and is normally latched in a reset position. A lost motion connection interconnects the actuator with a trip member which is in direct driving engagement with the releasable latch for the automatic trip means of the circuit breaker so that when the actuator is released, movement thereof is transmitted through the trip member to the circuit breaker latch for tripping of the latter. Each auxiliary feature module also includes a reset member which acts to automatically reset the actuator after each tripping operation thereof. The reset member is in direct driving engagement with the cradle of the circuit breaker contact operating mechanism so that movement of the cradle towards its tripped position will operate the reset member in a direction to reset the actuator.

Abstract: A bipolar protective switch has a two-piece housing. An electromagnet constitutes the actuating device made either in the form of a zero voltage actuator or an excess current actuator. The armature of the electromagnet drops in the event of a voltage failure or is attracted if an excess current appears, thus disconnecting the switch. The switch can be turned back on again only after the voltage returns or normal current returns by the actuating device. A rocker is disposed on the narrow upper surface between the two pieces of the housing as the actuating member. The electromagnet and connecting members are disposed on the underside of the housing, a portion of the electromagnet being located between the two pieces of the housing. A support of an insulating material, is disposed in the housing upon which support connecting members are disposed.

Abstract: A single pole circuit breaker module is constructed so that its housing is provided with frangible sections aligned with the pivot pins for the contact arm, the cradle and the operating mechanism latch. These pins are keyed to the elements mounted thereon and each pin is provided with a formation to engage a complementary formation projecting sideways from an auxiliary feature module. The latter includes one or more auxiliary devices. In the case of an auxiliary switch module, the switch thereof is connected to the contact arm pivot pin so that contact arm motion is transmitted to operate the auxiliary switch thereby indicating whether the circuit breaker is open or closed. In the case of an alarm switch auxiliary module, the switch thereof is connected to the pivot pin for the cradle whereby the tripping of the cradle is effective to operate the alarm switch.

Abstract: A multi-pole excess current circuit breaker assembly has a plurality of single-pole circuit breakers. In each of the latter the electric contacts are openable by a spring-loaded tripping mechanism actuated by a release lever as the release lever is moved from a first position to a second position by an excess current responsive device. The actuated tripping mechanism moves the release lever from the second position to a third position.

Abstract: A molded case circuit breaker comprising a case divided longitudinally into two approximate half cases. Each case defines an arcing chamber. Further, each half case has a side wall, an end wall, and a top wall. The end walls of each half case define an opening through which the arc gases are vented. The top walls of each half case define an inverted U-shaped cavity. A V-shaped screen has one leg thereof placed against the end walls to restrict the opening. The other leg of the V-shaped screen extends into the U-shaped cavity, but is spaced from the wall defining the U-shaped cavity. The V-shaped screen has legs which are spaced apart to provide a space through which the arc gases may pass. The circuit breaker also includes a stationary contact surrounded on all sides but one by an arc runner which is keyed to a supporting conductor.

Abstract: A plurality of single pole circuit breakers stacked side-by-side are interconnected by a tie rod connecting the magnetic armatures of their respective instantaneous trip means. When one pole is caused to trip because of a fault condition a driving cam formation on the releasable cradle of the faulted pole engages the armature moving it in the tripping direction substantially beyond the point required for releasing the cradle latch in the faulted phase. Substantial movement beyond cradle release is permitted even though the magnetic air gap at the armature is small in that after this gap is closed the magnet is moved bodily in the tripping direction. This added movement assures that the tie rod shall transmit sufficient motion to all non-faulted poles to cause tripping thereof.

Abstract: A plurality of single pole circuit breakers stacked side-by-side are interconnected by a tie rod connecting the magnetic armatures of their respective instantaneous trip means. When one pole is caused to trip because of a fault condition, a driving formation on the releasable cradle of the faulted pole delivers a hammerlike blow to a cam means on the magnetic armature. The energy imparted to the armature by this blow causes the latch carried thereby to move in the tripping direction substantially beyond the point required for releasing the cradle latch in the faulted phase. This added movement assures that the tie rod shall transmit sufficient motion to all non-faulted poles to cause tripping thereof.

Abstract: Circuit-breaker system having a response time to shortcircuits of less than 4 milliseconds have multiple coordinated pole units wired in series in each phase. The system is able to clear a fault where the available current is high, for example 100,000 amperes at 240 volts AC although each pole unit may be of conventional construction having a current-interruption rating of only 5 or 10 thousand amperes. The operation exhibits current limiting properties, and the interruption process leaves the pole units remarkably free of arc damage.