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:
Mar. 06, 1979
Filed:
Jun. 25, 1976
Herbert S Strauss, Paramus, NJ (US);
Lawrence Sheinberg, Howell Township, Monmouth County, NJ (US);
Duro-Test Corporation, North Bergen, NJ (US);
Abstract
Safety devices for high intensity discharge lamps, having an outer envelope and an inner arc tube in which the arc discharge is produced, for extinguishing the arc in a relatively short period of time. A switching element is placed in series with the current supply to the arc tube and the element opens when the outer envelope is broken. In one embodiment, the switching element is a normally closed thermostatic switch in series with a second filament which is connected in parallel with a first filament. During starting the switching element is closed and both of the filaments are in series with the arc tube and both receive a part of the high starting lamp current. The thermostatic switch opens when the lamp reaches operating temperature so that all of the current passes through the first filament if the envelope breaks causing the first filament to burn out. The switch then closes so that all of the current passes through the second filament causing it to burn out. In another embodiment, a pressure sensitive switch is used which opens the current supply to the arc tube when the envelope breaks.