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. 11, 1980
Filed:
Oct. 18, 1978
Franciscus M Oostvogels, Eindhoven, NL;
Gustaaf Melis, Eindhoven, NL;
Aime P Van Laarhoven, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
High-pressure discharge lamps, having a sealed discharge vessel surrounded by a sealed glass envelope, are known in which an oxidizable metal foil (e.g. of molybdenum) is located, in the space between the vessel and the envelope substantial on the axis of the vessel and is electrically in series with the discharge path. If the envelope is fractured for any reason and the lamp is subsequently ignited, the temperature of the foil is increased due to the discharge current passing through it. The foil is oxidized, and hence fractured, by the air which has permeated said space and the lamp is, extinguished. Such oxidation and fracture normally takes about ten minutes. In accordance with the invention, the foil (14) in the space between the envelope (1) and vessel (2) is arranged close to the wall of the vessel adjacent to an electrode (6) so as to be heated mainly by heat generated in the vessel. This reduces the fracturing time to about one minute.