High pressure discharge lamp with overhung end arc tube and cermet ends
US4808882A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 4, 1986 |
| Grant date | Feb 28, 1989 |
| Priority date | — |
| Expiry date | Aug 4, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J61/363
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An arc tube for a high pressure discharge lamp comprises a sealing element displaced from the end and sintered within the arc tube to form an overhung end. An electrically conductive cermet end member has a boss member which fits within a central aperture in the sealing element to thereby centralize the cermet end member within the arc tube. The cermet end member is therefore positioned within the arc tube independently of the arc tube wall and any distortion of the arc tube which has taken place during sintering of the sealing element has no effect. Preferred dimensions of the components are given so that cracking of the cermet end member is avoided and suitable electrical resistance is achieved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.