Fuji Electric Co., Ltd.

Fujitsu Corporation

Jun Oyama

Naoshi Uchida

Koji Asakawa

Katsunori Kuboyama

Masao Miura

Yasunori Otsuka

Tatsunori Takahashi

Kentaro Toyama

Kiyoshi Kandatsu

Isamu Nagahiro

Hiroyuki Sogo

Hisaji Shinohara

Akihiko Kohanawa

Nobuo Asahi

Mitsuyoshi Yamazaki

Kouji Asakawa

Makoto Unuma

A system for mobile communication, based on code division multiple access includes base stations, each of which communicates with mobile stations by using a plurality of radio frequencies covering respective cells, the respective cells including a first cell covered by a first radio frequency and a second cell covered by a second radio frequency. The system further includes a base-station controller which communicates with the base stations, and controls the mobile stations to switch from the first cell of a first base station to the first cell of a second base station via a soft hand-off operation and switch between the first cell and the second cell within any base station via a hard hand-off operation, the base-station controller providing the mobile stations with no direct switch between the second cell of the first base station and the second cell of the second base station.

Code-division-multiple-access mobile communication system accommodating increased number of mobile stations

A system for mobile communication based on code division multiple access includes base stations, each of which communicates with mobile stations by using a plurality of radio frequencies covering respective cells, the respective cells including a first cell covered by a first radio frequency and a second cell covered by a second radio frequency. The system further includes a base-station controller which communicates with the base stations, and controls the mobile stations to switch from the first cell of a first base station to the first cell of a second base station via a soft hand-off operation and switch between the first cell and the second cell within any base station via a hard hand-off operation, the base-station controller providing the mobile stations with no direct switch between the second cell of the first base station and the second cell of the second base station.

Code-division-multiple-access mobile communication system accomodating increased number of mobile stations

An overload tripping device includes a temperature-compensating bimetal operating as a tripping lever and interposed between an output lever of a differential shifter mechanism linked with a main bimetal and a latch receiver of an opening-and-closing mechanism section of a circuit breaker. The temperature-compensating bimetal has an intermediate portion journaled on a bimetal holder. An operating arm made of a light molding material is attached to a tip of the temperature-compensating bimetal so as to push the latch receiver. Additionally, a balance weight may be installed on the temperature-compensating bimetal to balance inertial moments on the opposite sides of the bimetal. Thus, the circuit breaker is prevented from being inadvertently tripped due to external stimulus.

Overload tripping device for circuit breaker

A contact shoe device for a circuit breaker is formed of a case, at least one pair of fixed contact shoes disposed in the case, at least one movable contact shoe disposed in the case for bridging the pair of the fixed contact shoes, and at least one pair of contact springs cooperating with the movable contact shoe. The contact springs urge the movable contact shoe to the pair of the fixed contact shoes to close an electric path between the pair of the fixed contact shoes. The movable contact shoe is separated from the pair of the fixed contact shoes against the contact springs when the electric path is open.

Contact shoe device for circuit breaker

A high-frequency circuit apparatus includes two high-frequency circuits (,) mounted on a printed circuit board (,), two rows of first plated through holes (,) which connect upper and lower ground plates (,) on the upper and lower surfaces of the printed circuit board (,) and which are arrayed in a first direction so that the two high-frequency circuits (,) are disposed between the first plated through holes, and at least two columns of second plated through holes (,) which are arrayed in a second direction different from the first direction, between the two high-frequency circuits to connect the ground plates on the upper and lower surfaces of the printed circuit board, to thereby form a waveguide resonator. A variable capacitance diode can be provided to be connected to a conductor pattern which is electrically isolated from the ground plates and the ground plates so as to adjust the resonance frequency of the waveguide resonator.

High-frequency circuit apparatus

An insulated container of a circuit breaker is divided into three vertically-arranged portions including a case, a middle case, and a cover. A fixed contact shoe and a movable contact shoe are accommodated in the case. An opening and closing mechanism and an overcurrent trip device are accommodated in the middle case. A holder slidably passing through a hole in a bottom wall of the middle case by an operation of the opening and closing mechanism is moved linearly and perpendicularly to the bottom wall to open and close the movable contact shoe. A gap in the hole between the holder and the bottom wall is very small due to the straight movement of the holder, so that an arc gas generated in the case is completely shut down by the bottom wall and does not reach the opening and closing mechanism in the middle case during current interruption.

Circuit breaker with metal melt isolation device

A circuit breaker is formed of a stationary contact member bent back into a U-shape and having a stationary contact at a bent back portion thereof, a moving contact member situated adjacent to the stationary contact member to be able to contact with the stationary contact, a plurality of grids laminated vertically with a space therebetween, and a unitary molded insulator situated around the stationary contact member. The insulator includes a pair of side walls facing to each other, and a plurality of slots arranged in the opposed side walls to vertically space apart from each other. The grids are inserted into the slots to be vertically piled when the circuit breaker is assembled. The circuit breaker can be easily assembled.

Circuit breaker with arc quenching device and vent

An arc quenching device for a circuit breaker having a stationary contact member and a moving contact member includes a magnetic element formed of an arc quenching core and a base plate. The arc quenching core includes a back wall, and two side walls extending from lateral sides of the back wall. The base plate extends substantially perpendicularly from a lower side of the back wall in a direction as in the side walls, and is fixed to the stationary contact member. The base plate includes a U-shaped magnetic driving core situated near a stationary contact point and extending upwardly from the base plate to surround the stationary contact point, and an arc horn integrally formed with the base plate and obliquely extending toward the back wall from a portion near the stationary contact point. Arc formed between the stationary contact member and the moving contact member is moved by magnetic driving force formed by the magnetic driving core to the arc quenching core to be quenched therein through the arc horn.

Circuit breaker arc quenching device with venting structure including

A circuit breaker having at least one phase or pole including a first movable arm having a first contact and a second movable arm having a second contact. The first arm is driven by a switching gear. The second arm is disposed opposite to the first movable arm such that the second contact contacts the first contact when a normal current flows. The first arm exerts an electromagnetic repulsive force in such a direction that the first and second arms repel each other to open the first second contacts when a current exceeds a predetermined value. The second arm is pivotally supported by a support angle fixed on a housing and is electrically connected via a flexible lead with a terminal also fixed on the housing. The support angle and the terminal are fitted to an insulator such that the support angles, the terminal and insulator are assembled in a unitary construction.

Circuit breaker

A repulsion type circuit breaker movable contact device comprising a first movable contact, an opening/closing mechanism which drives the first movable contact for opening and closing, a second movable contact for contacting the first movable contact, the second movable contact being freely pivotable and adapted to receive an electromagnetic repulsion force from said first movable contact, and a contact spring comprising a twisted coil spring disposed with its twisting fulcrum displaced from the rotational pivot of the second movable contact, the contact spring urging the second movable contact into contact with the first movable contact, whereby upon flow of a predetermined amount of electric current through the first and second movable contacts, the electromagnetic repulsion force moves the second movable contact apart from the first movable contact.

Repulsion type circuit breaker control device

A circuit breaker in which a movable contactor is held by a holder of electrically insulating material which is rotatably supported through a switching shaft on a casing. The movable contactor is driven by a switching mechanism to be swung about the switching shaft together with the holder to perform a switching operation. The movable contactor is slidably electrically connected to a connecting conductor secured to the casing.

There is disclosed a circuit breaker overcurrent tripping device. This tripping device includes: a fixed iron core accommodating a bimetallic strip in which a flow of an electric current is present, the bimetallic strip bending when an overcurrent is present; a movable iron core attracted to the fixed iron core when the electric current becomes a short circuit accident current; a tripping mechanism operated both by the movement of the movable iron core or the bending of the bimetallic strip; a fixed contact point connected via a connecting wire to a load terminal; a movable contact point fixed to the movable iron core and connected via a conductor wire to a fixed end of the bimetallic strip; and a flexible conductor for connecting a free end of the bimetallic strip to the load terminal. In this configuration, the fixed iron core is wound with at least one turn of the flexible conductor, thereby increasing the magnetic force attracting the movable iron core to the fixed iron core. A shunt circuit is formed when the movable iron core contacts the fixed iron core, thereby reducing the current overload on the bimetallic strip, and preventing the bimetallic strip from damage.

Circuit breaker overcurrent tripping device

A circuit breaker includes an insulating case, a fixed contact, and an insulating member covering the top surface of the fixed contact. A first end of the insulating member is received in a locking slot of the case and a second end includes an opening through which a raised portion of the fixed contact extends. A contact point is provided on the raised portion of the fixed contact.

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Kawasaki, Japan

Jun Oyama