The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 12, 2002
Filed:
Jun. 02, 2000
Toshinori Kimura, Tokyo, JP;
Kenichi Koyama, Tokyo, JP;
Hiromi Koga, Tokyo, JP;
Atsushi Sawada, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A vacuum switch includes a pair of windmill-shaped electrodes within a vacuum tube and including windmill portions and contact portions. Each of the windmill-shaped electrodes is arranged such that a component of a magnetic flux parallel to a contact surface and serving as an arc driving force with respect to a range of 0.5 mm from the contacting surface contacting the contacting portion of a leg portion of an arc has a magnetic flux density equal to or larger than 0.01 tesla with respect to an electric current of 1 kA, at any point on the contacting surface. The ratio of an inner diameter Di of the contact portion to an outer diameter D of the windmill-shaped electrodes is equal to or greater than 0.4, the difference in thickness between the windmill portions and the contact portions is equal to or less than 5 mm, and each of the windmill-shaped electrodes is connected to one of the pair of electrode rods, and a ratio of a diameter d of the connection portion of the electrode rod to an inner diameter Di of the contacting portion is equal to or less than 0.6. The windmill-shaped electrodes may be a Cu—Cr material including 20-60 weight % of Cr.