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:
May. 20, 2003
Filed:
Nov. 29, 2001
Yusuke Makino, Aichi, JP;
NGK Spark Plug Co., Ltd., Aichi, JP;
Abstract
A metal-ceramic composite (a vacuum switch unit ) having a metal member having a tubular portion and a cylindrical ceramic member The metal-ceramic composite (the vacuum switch unit ) has a structure in which an end face of the tubular portion of the metal member is butt joined via a joint metal layer to an end face of the cylindrical ceramic member in an edge sealed manner. In order to provide a metal-ceramic composite having a high joint strength which is less likely to cause defects such as cuts or cracks at the joint, the joint metal layer and the ceramic member contact each other at an annular region of W (mm) in average width which extends circumferentially about the end face of the ceramic member Furthermore, W and D have respective values which satisfy D≧30 {circle around (1)}; and (1/60)×D≦W≦(D/30)+3.1 {circle around (2)} where D (mm) is an outer diameter of the ceramic member.