Hitachi, Ltd.

The Tokyo Electric Power Company, Incorporated

Kuze Bellows Kogyosho Co., Ltd.

Toshio Horikoshi

Ayumu Morita

Ryutaro Yamamoto

Takashi Sato

Toru Tanimizu

Youichi Ohshita

Tooru Tanimizu

Masayoshi Hayakawa

Yoshiyasu Watanabe

Yoshiharu Yotsumoto

Nobuhiro Kuroda

Kazuo Kano

Yasunobu Kanou

Koji Kondou

Takanori Hashimoto

A bellows, of which one end portion is fixed to a movable lever passing through a vessel wall and the other end portion of which is fixed to the vessel wall, has a spring constant at a central portion in an expansion direction which is smaller than that at the end portions in the expansion direction. The bellows damps stress concentration at the end portions and improves the life thereof, without enlarging the size of the bellows. The bellows may be used in a vacuum switch.

Bellows and vacuum switch using the bellows

In an insulated type switchgear device in which a pair of arc electrodes are separably disposed in an opposing manner in a vacuum tube, and having a movable conductor extending from a back face of a movable one of the arc electrodes to the outside of the vacuum tube, the pair of arc electrodes are designed to be separated through a rotation of the movable conductor around a predetermined main axis. The movable arc electrode is structured in such a manner that an electrode center of the movable arc electrode, when the movable arc electrode is brought into its circuit breaking position, is to be located near a center axis of the stationary arc electrode, whereby the center of the movable arc electrode is offset from the center axis of the stationary arc electrode when the pair of arc electrodes are brought into their circuit making position, and whereby an insulation type switchgear device is provided which suppresses a possible offsetting of arc electrodes at a circuit breaking position thereof, improves circuit breaking performance thereof, and permits downsizing thereof.

Insulated type switchgear device

In a vacuum type switch gear device an L shaped stationary and movable conductors arrangement, a transitive portion from one spiral arc groove to a neighboring another spiral arc groove on the surface of a movable electrode defined by the terminating end portion of the one spiral groove, the starting end of the adjacent neighboring other spiral groove and the outer circumferential edge portion of the movable electrode is arranged in a substantially overlapping relationship in a vertical direction with the movable conductor. Thus an adverse effect of a current loop flowing through the movable conductor against an arc generated between movable and stationary electrodes is limited to thereby improve the circuit breaking performance.

Vacuum type switch gear device having L shaped stationary and movable

A protection apparatus for a spot network substation has a plurality of receiving lines connected between a network bus and a plurality of power sources. Each receiving line is connected to a primary switching device, a network transformer and a protector CB. A detector for detecting a phase of each receiving line voltage and a judging unit for judging the detected phase are provided on the primary side of each network transformer. A previously stored basic phase is compared with the detected phase of the receiving line voltage. If there is a lag in the detected phase of the receiving line voltage, it is judged to be a power-stop of the corresponding power source and the protector CB is tripped.

Protection system for power receiving station

Growing community of inventors

Fujioka, Japan

Toshio Horikoshi