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.

Date of Patent:
Jul. 30, 2002

Filed:

Jun. 14, 2001
Applicant:
Inventors:

Kenji Watanabe, Tokyo, JP;

Kumi Uchiyama, Tokyo, JP;

Kiyoshi Kagenaga, Tokoy, JP;

Junichi Sato, Tokyo, JP;

Eiji Kaneko, Tokyo, JP;

Mitsutaka Honma, Tokyo, JP;

Hiromichi Somei, Tokyo, JP;

Assignee:

Kabushiki Kaisha Toshiba, Kawasaki, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01H 3/375 ;
U.S. Cl.
CPC ...
H01H 3/375 ;
Abstract

The flux density Bct is applied at the center area of the electrode. The flux density Bct is adjusted within the range A of 0.75 to 0.9 times greater than the axial flux density Bcr which gives the lowest arc voltage between the electrodes against each breaking current. The axial flux density monotonously increases from the center to the circumferential area of the electrode. Here, the radial position where the axial flux density Bcr which gives the lowest arc voltage Vmin is adjusted within the region B of 20% to 40% of the radius of the electrode. The axial flux density is made monotonously increase in an outer area from the region B and give the maximum value Bp in a circumferential area equal to or beyond 70% of the radius of the electrode. The maximum value Bp is adjusted within the range C of 1.4 to 2.4 times greater than the flux density Bct given at the electrode center.


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