Mitsubishi Denki Kabushiki Kaisha

Yoshiaki Kobayashi

Hiroshi Fujii

Shinji Yamagata

Hiroaki Fujihisa

Hirotoshi Ohishi

Mitsugu Takahashi

Takao Mitsuhashi

Fumiyuki Hisatsune

Tsukasa Iio

Setsuo Hosogai

Shinsaku Yamasaki

Kouhei Fujiwara

Shirou Murata

Toshiyuki Tanibe

Kiyoshi Matsuura

Yutaka Nakayama

A circuit breaker-includes: a casing having a base and a main cover secured to the base, the casing accommodating a circuit breaking mechanism; a recesses formed in one surface of the main cover, the opposite surface of which is on the side of the base, the recess being adapted to receive an auxiliary device of the circuit breaking mechanism; and an auxiliary cover mounted on the main cover in such a manner as to close the recess. The circuit breaker is automatically tripped when the auxiliary cover is opened, thus permitting installation of the auxiliary device thereon with high security.

Circuit breaker

The current limiting circuit breaker comprises a circuit breaker (1A) and at least one current limiting unit (1B); the circuit breaker (1A) has load side terminals (12) and power-source-side or connection terminals (2a), and the current limiting unit (1B) is unitized to be simply connected to the circuit breaker (1A) or to another current limiting unit (1B) at their power source side terminals; the current limiting unit (1B) has current limiting connection terminals (25a) which ride on the circuit breaker connection terminals (2a) or power-source-side terminals (20a) of another current limiting unit (1B) for connection, to the circuit breaker (1A) or another current limiting unit (1B).

Current limiting circuit breaker

In a circuit breaker of double break type, a first moving contact arm and a second moving contact arm are pivoted on a common pin shaft in a manner to move mechanically independent from each other and are electrically connected at the parts near the pivoted ends by a flexible conductor, such as a braided wires, and thereby stable and reliable contacts of the moving contacts on the stationary contacts are assured.

In a twin-contact type current limiting apparatus in which two contacts are electrically connected in series with each other, each of movable contact arms (23a, 23b) is extended in substantially parallel with and along each of stationary contact arms (21a, 18a), thereby obtaining balanced electromagnetic repulsions when an excessive current flows.

Current limiting apparatus

In a circuit breaker, an arc is produced between a pair of switchable contact members when these contact members are opened due to overcurrent. An arc extinguishing apparatus is employed to extinguish an arc produced between the opened contact members. The arc extinguishing apparatus includes a plurality of U-shaped metal arc extinguishing plates which are stacked, and a pair of insulating plates made of a synthetic resin. These insulating plates are mounted on both inside surfaces of leg portions of the extinguishing plates.

Multi-phase circuit breaker employing arc extinguishing apparatus

In a circuit interrupter having a base with a stationary contact, a toggle link mechanism including an operating handle supported by the base for manually operating the circuit interrupter and a link rotatably connected at one end to the operating handle; a movable member pivotally supported on the base and having a movable contact on one pivoting end portion; a latch lever pivotally supported on the base for latching the link so that the movable member and the link are normally connected to hold the movable member against the force of a biasing spring so that the contacts are in engagement, and an overcurrent trip means including a plunger actuated responsive to a large overcurrent to strike and pivot the latch lever so as to release the link from the movable member to move and separate the contacts, the improvement comprising a pivotal support for the latch lever and the movable member on the base, allowing both bodily movement and pivotal movement only of the movable member; the pivotal support including a pin fixed to the base extending through a circular hole in the latch lever and through a hole in the movable member which is elongated to allow bodily movement thereof without separating the contacts, and pivotal movement thereof separating the contacts by the biasing spring after a delay determined by the length of the elongated hole upon pivotal movement of the latch lever by the plunger striking the latch lever responsive to large overcurrent, releasing the link from the movable member, whereby any impact force due to the plunger striking the latch lever is transmitted to the base through the pin.

Circuit interrupter

An operating handle locking device for use with an electrical switchgear such as a circuit interrupter comprises a locking plate for blocking the movement of the operating handle between the ON position and the OFF position, and a support plate secured to the circuit interrupter for supporting the lock plate, the locking plate being locked in the operating handle locking position relative to the support plate by a locking member. The switchgear may have a trip button for tripping the switchgear from the exterior, and the locking plate may have a cover portion for covering the trip button when the locking plate is in an operating handle locking position. A cover portion may also be provided in the locking plate for covering the reset button of the circuit interrupter when in the operating handle locking position.

Operating handle locking device for circuit interrupter

A circuit interrupter comprising a pair of separable contacts at least one of which is movable, and an operating mechanism operatively connected to the movable contacts for opening and closing the contacts. The operating mechanism includes a movable contact arm having mounted thereon the movable contact, a latch lever pivotally mounted on the movable contact arm, and a toggle link mechanism connected at its one end to an operating handle and the other end of which is directly engageable with said movable contact arm and the latch lever. The movable contact arm has a latch surface, and the latch lever has a latching end which, in cooperation with the latch surface, releasably catches the other end of the toggle link mechanism. The operating mechanism further comprises a yieldable member providing a yieldable stop surface for preventing the automatic return movement of the other end of the toggle link mechanism from an extended position after the trip operation to a reset position and for yieldably maintaining the other end of the toggle link mechanism at a position in which the toggle link mechanism is partly collapsed. The yieldable stop surface can be overcome by the manual moving effort on the operating handle.

A circuit interrupter comprising a pair of separable contacts at least one of which is movable, and an operating mechanism operatively connected to the movable contacts for opening and closing the contacts. The operating mechanism includes a movable contact arm having mounted thereon the movable contact, a latch lever pivotally mounted on the movable contact arm, and a toggle link mechanism connected at its one end to an operating handle and the other end of which is directly engageable with the movable contact arm and the latch lever. The movable contact arm has a latch surface, and the latch lever has a latching end which, in cooperation with the latch surface, releasably catches the other end of the toggle link mechanism. The movable contact arm further has formed thereon a stop surface for preventing the movement of the other end of the toggle link mechanism beyond the point at which the toggle link mechanism is partly collapsed when the contacts are welded to each other. A roller may be mounted on the other end of the second toggle link for quick and smooth operation of the operating mechanism.

A circuit breaker characterized by a roller guide member, 1a, provided on the inside wall of an upper part of the case 1. The roller quite member, 1a, has a curved shape designed to form or smooth curved path, 100, in cooperation with the roller receiving indents 5a and 56, so that the roller can be reliably reset in the roller-receiving indents 5a and 5b.

Growing community of inventors

Amagasaki, Japan

Yoshiaki Kobayashi