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:
Jan. 24, 1989
Filed:
May. 28, 1987
NGK Insulators, Ltd., Nagoya, JP;
Abstract
A discharge tube for a high pressure metal vapor discharge lamp is disclosed, which comprises a translucent alumina tubular body, first and second end plates of cermet having a firing shrinkage factor which is less than that of the translucent alumina tubular body, end first and second electrode support members partially embedded in inner sides of the first and second end plates, respectively. The first end plate is fitted to the first end portion of the alumina tubular body and bonded thereto through shrinkage fitting at a shrinkage fitting ratio of the tubular body to the first end plate being from 3 to 6% during a simultaneous sintering of the first end plate to the tubular body and a simultaneous bonding of the first electrode support member to the first end plate through shrinkage fitting at a shrinkage fitting ratio of the first end plate to the first electrode support member being from 4 to 16% when the alumina tubular body is fired to be translucent. The second end plate is fitted to the second opposite end portion of the tubular body and is bonded thereto by means of a frit. When the discharge lamp is in use, the second opposite end portion is located at a vertically higher position than the first opposite end portion. A method of producing such discharge tubes is also disclosed.