Discharge lamp with automatic shut off
US4629939A · kind A · utility
2Cited by
6References
11Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 21, 1984 |
| Grant date | Dec 16, 1986 |
| Priority date | — |
| Expiry date | Dec 21, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J61/50
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A high intensity discharge lamp with a safety switch which automatically shuts off the lamp upon rupture of the outer envelope. The switch is formed by a carbon rod disposed in the interior space between the arc tube and the outer envelope and connected in series with one of the electrodes so that the current flow through the rod maintains it at an elevated temperature during operation of the lamp. Upon rupture of the outer envelope, the carbon rod oxidizes and falls, thereby interrupting the electrical path to the electrodes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.