US4545799A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making direct seal between niobium and ceramics
Assignee: Osram Sylvania Inc
•
Filing: 1983-09-06
•
Granted: 1985-10-08
•
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 21:15
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.
References Cited (Backward Citations)
US2561520A
Cited
DE866371C
Cited
US2699594A
Cited
US3035372A
Cited
US3281309A
Cited
US3428846A
Cited
US4004173A
Cited
US3441421A
Cited
US3448319A
Cited
US3564328A
Cited
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 |