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:
Sep. 03, 1985
Filed:
Sep. 03, 1982
Applicant:
Inventors:
Assignee:
Thorn EMI plc, London, GB;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01J / ; H01J / ; H01J / ; H01J / ;
U.S. Cl.
CPC ...
313624 ; 313625 ; 313626 ; 313634 ;
Abstract
In a high pressure sodium discharge lamp it has been found that rectification can be prevented by ensuring the amalgam does not make electrical contact with the electrode. To achieve this according to the invention a small shoulder member is provided on the inside face of the end wall. Although the small height effectively reduces the temperature differential between the bottom of the shoulder and the top the necessary differential to prevent the amalgam condensing out the top of the shoulder member is maintained by ensuring the width of the shoulder member is a predetermined minimum thickness.