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:
Jul. 10, 1984
Filed:
Jan. 07, 1982
Miklos Csapody, Budapest, HU;
Endre Oldal, Budapest, HU;
Egyesult Izzolampa es Villamossagi RT., Budapest, HU;
Abstract
A tubular discharge vessel for high pressure sodium vapor lamps has a wall 1 made of light-transmitting material. The tube 1 is hermetically sealed at each end by a respective ceramic stopper 2 through which is passed a respective current lead-in wire 11. An electrode 8 is joined via a shank 10 to the current lead-in wire 11. The interior of the tube is filled with noble gas(es) and metal additive(s), e.g. sodium, mercury and/or cadmium. A cavity 9, preferably of rotationally symmetrical shape is formed in at least one of the stoppers 2. In operation of the discharge tube the cavity 9 is the cold spot. i.e. the internal wall of the lowest temperature. The volume of the cavity 9 is at least equal to the volume of the metal additives in their liquid phase. In this way, in operation of the tube, the metal additives always condense in the cavity, the vitreous enamel bonds between the tube wall and the stoppers are free from chemically aggressive effects and whereby the self-stabilizing thermal processes taking place in the discharge vessel are promoted.