Mitsubishi Denki Kabushiki Kaisha

Kiyomi Yamamoto

Shinji Yamagata

Fumiyuki Hisatsune

Hajimu Yoshiyasu

Junichi Terachi

Shigemi Tamaru

Yuichi Wada

Hiroshi Fujii

Setsuo Hosogai

Hideo Suhara

A circuit interrupter comprises a housing including a housing wall, an interrupting mechanism including a pair of separable contacts and an operating mechanism, and an optional accessory unit used in connection with an opening operation of the interrupting mechanism. The optional accessory unit may be a unit which includes a movable member operable in connection with the opening operation of the interrupting mechanism, such as an alarm switch, an auxiliary switch, a voltage trip device or an under voltage trip device. The optional accessory unit may be a connecting terminal block connectable between an external circuit and the circuit interrupter. The housing has formed in the outer surface thereof a receptacle cavity for receiving therein the optional accessory unit. When the unit is received in the cavity, no substantial portion of the unit projects from the housing. A fastening means comprises a slider, a guide rail engaging the slider for allowing a sliding movement of the optional accessory unit only in the direction of extension of the guide rail, and a screw for securing the optional accessory unit to the housing wall.

Circuit interrupter with detachable optional accessories

A circuit interrupter which comprises, in a compartment defined in an electrically insulating housing, a pair of separable contacts defining, when separated, an arcing region therebetween, and an operating mechanism, including a tripping unit and an operating handle, for opening and closing the separable contacts. The housing which includes an electrically insulating bottom wall has a gas exhaust passage having an inlet opening in the inner surface of the housing. The inlet of the gas exhaust passage is located in the bottom wall at a position effective for exhausting an arced gas generated in the arcing region without contacting the operating mechanism.

Circuit interrupter

A circuit breaker in which arc shielding members are provided for predetermined contacts among a plurality of contact pairs arrayed in parallel, so that the arc will take place between predetermined contacts when the contacts are opened. The arc shielding members are made of a material having resistivity greater than that of the conductors to which the contacts are attached. The arc shielding members work to effectively inject metallic particles of contact material into the arc, so that the arcing voltage is rapidly raised and so that feet of the arc will not spread to the conductors in the vicinities of the contacts.

Circuit breaker

A circuit breaker having means for quickly opening a pair of contacts, a U-shaped flux board which surrounds the conductors that have contacts attached to the end portions thereof, so that the electromagnetic repulsive force produced by the electric current that flows through the opposing conductors in opposite directions relative to each other, will be added to the operation of the contact-opening means. The circuit breaker of the invention is further equipped with arc shielding members surrounding the contacts, so that the arc established across the contacts will not stretch to the conductors in the vicinities of the contacts, and so that the arcing voltage is greatly increased.

The present invention combines the provision of arc shields surrounding the contacts of a circuit breaker with a magnetic driving means to raise the arc voltage of an arc drawn across the contacts and to effectively drive the arc, whereby the performance of the circuit breaker is improved.

Growing community of inventors

Fukuyama, Japan

Kiyomi Yamamoto