Patent US4545799A successfully refreshed from Google Patents.
US4545799A
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US
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Method of making direct seal between niobium and ceramics
Assignee: Osram Sylvania Inc
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Filing: 1983-09-06
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Granted: 1985-10-08
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Expires: 2003-09-06
Abstract
Abstract A high pressure arc lamp has a ceramic arc tube envelope. A niobium feedthrough positions electrodes within the tube. A ceramic insert at each end of the tube forms a direct high temperature hermetic seal with the niobium feedthrough and the ceramic tube without the use of frits or brazing.
Inventors
- 👤 William H. Rhodes
- 👤 Caryl S. Pitt
- 👤 John J. Gutta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:13
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/24; H01J9/32; H01J9/323; H01J61/00; H01J61/02; H01J61/36; H01J61/366
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
149 words
A method of making a tube assembly for a high pressure discharge lamp comprised of the steps of: a. providing a tube made of unsintered compressed ceramic powder b. providing a niobium feedthrough; c. providing an insert made of unsintered compressed ceramic powder having a similar thermal expansion coefficient as that of said tube, said insert in the shape of a disc with an axial hole; d. inserting said unsintered insert in an end of the unsintered tube; e. heating said insert and tube until both are partially sintered and bonded together; f. positioning said niobium feedthrough in the axial hole of said insert; and g. heating said tube, insert and niobium feedthrough until said tube and insert are fully sintered and said insert is contracted and forced against said niobium feedthrough, forming thereby a brazeless, fritless hermetic seal at the interface between said insert and said niobium feedthrough.
Claim 2
Independent Claim
149 words
A method of making a tube assembly for a high pressure discharge lamp comprised of the steps of: a. providing a tube made of unsintered compressed ceramic powder b. providing a niobium feedthrough; c. providing an insert made of unsintered compressed ceramic powder having a similar thermal expansion coefficient as that of said tube, said insert in the shape of a disc with an axial hole; d. inserting said unsintered insert in an end of the unsintered tube; e. heating said insert and tube until both are partially sintered and bonded together; f. positioning said niobium feedthrough in the axial hole of said insert; and g. heating said tube, insert and niobium feedthrough until said tube and insert are fully sintered and said insert is contracted and forced against said niobium feedthrough, forming thereby a brazeless, fritless hermetic seal at the interface between said insert and said niobium feedthrough.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-10-07 | 1989-04-08 | 1989-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-07 | 1993-04-08 | 1993-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-07 | 1997-04-08 | 1997-10-08 | $7700.00 | Window Closed / Lapsed |