Hitachi, Ltd.

Yoshio Koguchi

Yukio Kurosawa

Yoshitaka Kojima

Toru Tanimizu

Yoshimi Hakamata

Katsuhiro Komuro

Shunkichi Endo

Masato Kobayashi

Shigeru Kikuchi

Masaya Takahashi

Hideaki Onozuka

Yohei Asakawa

Motohiro Kikuchi

An electrode comprises an electrode main body having a porosity, and the conductivity of the electrode main body at its part ranging from the arc running face to a stated depth is made higher than the conductivity at the section or the conductivity at the part ranging from the back surface to a stated depth. This brings about an improvement in circuit-break performance of a circuit breaker and also prevents the arc running face of the electrode main body from deteriorating.

Sintered body and electrode, method for surface densitication of these, process for manufacturing electrode by this method and circuit breaker

According to the present invention there are provided a highly reliable electrode of high strength which undergoes little change even with the lapse of time, and a method for making the same, as well as a vacuum valve using such electrode and a vacuum circuit breaker using such vacuum valve. The vacuum circuit breaker has a fixed electrode and a movable electrode, each comprising an arc electrode, an arc electrode support member for supporting the arc electrode, and a coil electrode contiguous to the arc electrode support member, the arc electrode, the arc electrode support member and the coil electrode being formed as an integral structure by melting, not by bonding, particularly the arc electrode support member and the coil electrode being constituted by a Cu alloy containing 0.05-2.5% by weight of at least one of Cr, Ag, W, V and Zr.

Vacuum circuit breaker as well as vacuum valve and electric contact used

Method forming an electric contact in a vacuum circuit breaker

Vacuum circuit breaker and electric contact

Growing community of inventors

Hitachioota, Japan

Yoshio Koguchi