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. 30, 1999
Filed:
Oct. 02, 1998
Karlene J Zuk, Hathorne, MA (US);
Jeffrey T Neil, North Reading, MA (US);
Christopher A Tarry, Portsmouth, NH (US);
Osram Sylvania Inc., Danvers, MA (US);
Abstract
A method of forming hollow bodies of ceramic material suitable for use as the discharge vessels of high intensity discharge lamps includes forming a fugitive core of substantially pure graphite having a configuration matching the interior configuration of the hollow body. A flowable powder, including binders, of the ceramic material is formed and added to fill the annular space between a flexible elastomeric mold defining the outer contour and the fugitive core defining the inner contour. The ceramic powder is isostatically compressed in the mold about the core to form a sub-assembly. The sub-assembly is removed from the mold, heated at a rate and time and in a suitable atmosphere to volatilize the fugitive core, and subsequently the sub-assembly is sintered to form the hollow body.