End seal manufacture for ceramic arc tubes
US5178808A · kind A · utility
2Cited by
7References
4Claims
0Family size
Inventors
Key dates
| Filing date | Oct 5, 1988 |
| Grant date | Jan 12, 1993 |
| Priority date | — |
| Expiry date | Oct 5, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B2237/765
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
An end plug for an arc tube for a high pressure discharge lamp is made by pressing alumina powder in a tapered cylindrical die so that the diameter of the as-pressed plug is greatest at that part of the plug that has the lowest as-pressed density. The variation in diameter of the as-pressed plug compensates for the variation in density so that upon high temperature sintering, the plug shrinks to a substantially uniform diameter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.