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. 21, 1992
Filed:
Dec. 31, 1990
Timothy W Graham, Union Springs, NY (US);
John Scoins, Skaneateles, NY (US);
Welch Allyn, Inc., Skaneateles Falls, NY (US);
Abstract
A low-wattage metal-halide discharge lamp has a tube of the double ended type that forms a bulb or envelope, a pair of electrodes, e.g., an anode and a cathode, which penetrate into an arc chamber inside the envelope, and a suitable amount of mercury plus one or more metal halide salts. The electrodes are each formed of a refractory metal, i.e., tungsten wire, extending through the respective necks into the arc chamber. The electrodes are of a composite design i.e., in the form of a club, with a lead-in wire of small diameter supported in the associated neck, and a post member of greater diameter supported on the lead-end wire. The post members are supported of contact with the necks and also out of contact with the bulb wall. The larger size of the post member allows heat at the tip to diffuse back into the post member, so that the metal tip will not evaporate. The narrow lead-in wire keeps most of the heat in the bulb, so that flow of heat out of the neck portions is limited. Lamps of this design achieve high efficacy at relative low power (below 30 watts).