Abstract: A multipolar circuit breaker of great breaking capacity prevents arc gas from blowing out from the side at the time of cutting off a short-circuit current. A stationary contact and a movable contact generating arcs when a short-circuit current is cut off, and an arc extinguisher extinguishing the arc are stored in an arc extinguisher casing. By forming the ceiling, the bottom and the sidewalls connecting the ceiling and the bottom of the arc extinguisher casing in continuity so that no gap is formed by an outward internal pressure, blow out of arc gas from the sidewall portion is suppressed.

Abstract: A multipolar circuit breaker of great breaking capacity prevents arc gas from blowing out from the side at the time of cutting off a short-circuit current. A stationary contact and a movable contact generating arcs when a short-circuit current is cut off, and an arc extinguisher extinguishing the arc are stored in an arc extinguisher casing. By forming the ceiling, the bottom and the sidewalls connecting the ceiling and the bottom of the arc extinguisher casing in continuity so that no gap is formed by an outward internal pressure, blow out of arc gas from the sidewall portion is suppressed.

Abstract: A trip device of a circuit breaker that operates speedily when an enormous abnormal current such as short-circuit current flows is provided. The trip device includes a pressure detection space having a wall portion formed of a repeatedly usable thin plate, an operating rod which protrudes from the pressure detection space when the pressure in the pressure detection space increases, and a return spring which returns the operating rod. The pressure detection space is arranged in the vicinity of switching contacts, and the operating rod is arranged to release a trip latch mechanism when it protrudes.

Abstract: In a circuit breaker utilizing a toggle link mechanism, the reset operation is facilitated. A block link including a reset pin, a first hole and a second hole is provided. The reset pin is inserted into a circular arc shape third hole formed concentric with the rotation of a trip lever formed at a secured frame. An actuating pin of a handle lever is inserted into the first hole. A shaft provided at a movable contact holder is inserted into the second hole. By this mechanism, the friction in the reset operation can be reduced to allow the reset operation to be perform by a smaller force. As a result, an auxiliary handle is not required. The handle and electrical operation devices can be reduced in size. Also, the operating handle is prevented from moving to the OFF position when the switching contacts are welded.

Abstract: A trip device of a main circuit breaker is provided which causes only a branch circuit breaker to be set into a tripped state when an abnormal current occurs at a load of the branch circuit breaker while keeping a closed state of the main circuit breaker. The trip device of the circuit breaker has a structure including a trip latch mechanism for opening switching contacts, a stationary core, a movable core which is attracted to the stationary core to release the latch mechanism of a trip lever, an operating pin for interrupting movement of the movable core while the movable core is attracted, an operating spring charged with force when the movable core is attracted, and an inertia roller holding the operating pin, kicked when the operating spring discharges the force, and moved to a position which does not interrupt movement of the movable core. Accordingly, this structure allows a selective tripping system to be implemented simply with small size and low cost.

Abstract: In response to the movement of a moving contact which can move with small force for a large distance until it contacts a stationary contact and requires large force to move for a small distance after the contacting, three cam means including a toggle roller and a toggle cam, a coupling shaft roller and a closing cam, and a closing cam and an operation lever roller, respectively are provided to effectively distribute the closing force of a closing spring.

Abstract: In a drawer type circuit breaker of the invention, when a first contact is clockwise pivoted by a switching mechanism, the contact tip of the first contact and the contact tip of a second contact are touched, and when the first contact is further clockwise pivoted, the second contact is counterclockwise pivoted against the elastic force of a spring to secure a predetermined contact pressure and a predetermined wiping stroke. A first drawer contact clamps the outer circumferential portion of the first contact and a first external connection terminal together by the elastic force of a spring to establish connection between the first contact and the first external connection terminal. A second drawer contact clamps the outer circumferential portion of the second contact and a second external connection terminal together by the elastic force of another spring to establish connection between the second contact and the second external connection terminal.

Abstract: A load value of an external load is detected by a load value detector. When a heat quantity recovered by a heat load from a heat engine or a fuel cell is smaller than a predetermined value, a CPU calculates electric power to be consumed by an electric heater based on a relation between a heat value of heat load relative to a load value of a generator or fuel cell and a heat quantity recovered from generator or fuel cell stored in a memory of a power setting unit, so that the sum of heat quantities recovered from waste heat of heat engine or fuel cell and from generated heat of electric heater by heat load is the predetermined value, thereby controlling electric heater according to the result.

Abstract: A drawer-type circuit interrupter is constructed with a first contact member having an open-and-close contact member, an open-and-close operation mechanism for operating said first contact member, an interrupter main body having a second contact member and a mounting frame having the external line contact terminals, wherein the second contact member is a movable-type provided with an open-and-close contact portion that is contactable with and separable from the first contact member on the one end thereof and a drawer contact member that contacts with an external line contact terminal on the other end thereof, and a compression spring for urging the second contact member into a direction for contacting the external line contact terminal on the other end of the second contact member. When the interrupter body is in the connected position the drawer contact portion on the other end of said second contact member and said external line contact terminal are into contact.

Abstract: Disclosed is a circuit breaker including a first linking member for switching fixed contacts provided in a main current path. The first linking member is operated by a circuit switching mechanism using a voltage-operated electromagnet, a forced contact parting mechanism upon short circuit condition using a current-operated electromagnet connected in series to the main path, and a spring releasing mechanism responsive to flow of overcurrent for operating. The forced contact parting mechanism upon short circuit condition includes a link mechanism including self-retaining/self-resetting function between the first linking member and the current-operated electromagnet.

Abstract: A contact structure of a switching device having a pivoted movable contact arm for reducing contact chatter, i.e., bounce, at the instant of closing or separation is given. Such chatter is mainly caused by clearances existing around pivots of the movable contact arm and operating mechanisms. A contact spring for applying a contact pressure when the switch is closed is provided between a portion of the movable contact arm at the other side of a contact in relation to the pivot of the movable contact and a stationary portion of the switching device. Also, a stopper is provided on a contact arm support member engagable with the contact arm at a side of the contact. With structure the movable contact arm and operating mechanisms are perfectly biased by the contact spring always in one direction and prevents free movement of the movable contact arm.

Abstract: In the overcurrent tripping unit for a circuit breaker, current transformers are provided for detecting currents flowing through respective phases of a main circuit, the secondary outputs of the current transformers are star connected, the primary outputs are polyphase full-wave rectified, the voltage drop based on the rectified positive/negative direct output of each phase is directed by first and second resistances to be applied to the control means, and a ground fault current is detected based on the secondary outputs of the current transformers to be applied to the control means.

Abstract: It is the main object of this invention to provide a circuit breaker in which the movable contacts have sufficient opening force and opening distance, and in which the breaking time is short. In order to attain the object, the circuit breaker of this invention is provided with a dead center link mechanism comprising a movable contact link which is rotatably supported by the arms of a cross bar which is operated so as to be capable of opening-closing the circuit and tripping by means of a trip-free mechanism, and a toggle spring which is bridged between the cross bar and the movable contact link. When a large current such as a short-circuit current flows, a movable steel plate attracted by an electromagnet for instantaneously tripping hits a rod for supporting the movable contacts which is connected to the movable contact link, whereby the dead center link mechanism makes the movable contacts open at high speed from the fixed contacts.

Abstract: The contact structure and the arc extinguisher means of a circuit interrupter are enclosed in an insulating housing of each pole and the operating mechanism is isolated from the contact structure and located outside of the housing. The housing for each pole forms an arc extinguisher amper with a detachably attached cover containing an arc extinguisher, and a contact chamber containing a contact structure in each pole. An interconnecting rod, located between the contact structure and the operating mechanism has a flange or barrier for covering an opening in the housing through which the rod extends. Upon contact separation, the electric arc increases the internal pressure within the housing, thereby rapidly effecting arc extinction. The dielectric strength between the contact structure and the operating mechanism is also greatly increased in comparison with conventional designs.

Abstract: The disclosed circuit interrupter comprises a magnetic core structure including a magnetic core and magnetic yokes defining an annular magnetic gap around the core, and a primary and a secondary coil wound on the core to form a current transformer. The movable contact arm is disposed in the magnetic gap to be magnetically driven to the open position, and a magnetic armature of an instantaneous trip means is disposed adjacent to the magnetic yokes so that it is magnetically actuated upon a short-circuit current. A bimetallic element of a thermally responsive trip means is electrically connected to the secondary coil of the transformer. The magnetic yokes include extended portions which serve as magnetic means for driving an electric arc established between the separated contacts into an arc extinguisher which is also disposed between the magnetic yokes.

Abstract: A time division multiplex transmission system for communication of a data signal in a time-multiplex fashion over a data signal transmission path comprises a clock pulse generator for generating two-phase clock pulses including a first train of one phase and a second train of opposite phase. The system further comprises a plurality of transmitters and receivers, each including a wave shaper for demodulating the two-phase clock pulses and producing a single-phase clock pulse train, and a station selection circuit for processing the single-phase clock pulse train to identify that period of time during which the particular transmitter or receiver is selected for transmission or reception. Each transmitter and receiver also comprises a reset signal detector circuit, responsive to the detection of an intermission period in the clock pulse train, to reset the station selection circuit of the particular transmitter or receiver, thus achieving overall synchronization of the transmitters and receivers in the system.

Abstract: One electrode is rigidly fitted into a hollow metallic cylinder and the other electrode is coaxially fixed within the cylinder through a cylindrical insulation. An insulating disc is opposite to the cylindrical insulation to form them an annular arrow gap between them. The gap is filled with a self-restoring type current limiting material to normally form a current passageway between both electrodes. The current limiting material is caused to be first evaporated in a narrower portion of the gap in response to a flow of overcurrent through it.

Abstract: The disclosed instantaneously tripping device includes a stationary iron core encircling a conductor and responsive to a flow of shortcircuiting current through the conductor to attract a movable iron core to open contacts. A locking and releasing plate are operatively coupled to the movable core to transfer the movement of a closing latch to the latter. After the completion of the closing operation effected by a switching mechanism, the locking plate locks the movable core while only during the closing operation of the switching mechanism does the releasing plate release the movable core to permit it to be attracted by the stationary core.