US4103200A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Arc tube end seal and method of forming
Assignee: Philips North America LLC
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Filing: 1977-05-13
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Granted: 1978-07-25
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Expires: 1997-05-13
Abstract
Abstract An improved arc tube end seal and the method of forming that seal in a high pressure sodium discharge lamp is disclosed. The method includes precoating the refractory metal end cap with a slurry of metallic silicon and baking the end cap prior to accomplishing the bonding of the end cap to the arc tube with a conventional sealing frit.
Inventors
- 👤 Ranbir S. Bhalla
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:10
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/36
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
99 words
A sealed high pressure sodium lamp arc tube, said arc tube comprising: an elongated tubular alumina arc tube body; a refractory metal end cap associated with each end of said arc tube body; and means sealing said end caps to the ends of said arc tube body, said means sealing said end caps to said ends of said arc tube body including a coating of silicon metal on the interior surface of said refractory metal end caps and a glassy sealing frit principally comprising alumina and calcia interposed between said silicon metal coating and said alumina arc tube body.
Claim 2
Dependent Claim
99 words
A sealed high pressure sodium lamp arc tube, said arc tube comprising: an elongated tubular alumina arc tube body; a refractory metal end cap associated with each end of said arc tube body; and means sealing said end caps to the ends of said arc tube body, said means sealing said end caps to said ends of said arc tube body including a coating of silicon metal on the interior surface of said refractory metal end caps and a glassy sealing frit principally comprising alumina and calcia interposed between said silicon metal coating and said alumina arc tube body.
Claim 3
Dependent Claim
27 words
The sealed high pressure sodium lamp arc tube according to claim 1, wherein said alumina arc tube body is polycrystalline alumina and said refractory metal is niobium.
Claim 4
Dependent Claim
52 words
An arc tube for a high pressure sodium discharge lamp comprising: an elongated tubular ceramic arc tube body member; a pair of refractory metal end caps having a silicon metal coating on the interior surface thereof sealed to and closing off the ends of said elongated tubular ceramic arc tube body member.
Claim 5
Dependent Claim
52 words
An arc tube for a high pressure sodium discharge lamp comprising: an elongated tubular ceramic arc tube body member; a pair of refractory metal end caps having a silicon metal coating on the interior surface thereof sealed to and closing off the ends of said elongated tubular ceramic arc tube body member.
Claim 6
Dependent Claim
15 words
The arc tube according to claim 3 wherein said refractory metal end caps are niobium.
References Cited (Backward Citations)
US3598435A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-24 | 1982-01-23 | 1982-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-24 | 1986-01-23 | 1986-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-24 | 1990-01-23 | 1990-07-25 | $7700.00 | Window Closed / Lapsed |