Patent US3723784A successfully refreshed from Google Patents.
US3723784A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alumina ceramic lamp having heat-reflecting shields surrounding its electrodes
Assignee: General Electric Co
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Filing: 1971-04-15
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Granted: 1973-03-27
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Expires: 1991-04-15
Abstract
Abstract A high intensity sodium vapor lamp utilizing a tubular envelope of alumina ceramic closed at the ends by niobium end caps which support activated tungsten electrodes and which contains mercury and an excess of sodium not all of which is vaporized during operation. It is desirable that the excess of sodium and mercury condense in the exhaust tube or appendage and not about the interface between the end cap and the sealing glass binding it to the alumina envelope. This result is achieved by providing a heat shield of polished refractory metal about the ends of the arc tube next to the end caps.
Inventors
- 👤 J Sulcs
- 👤 Kimm R Mc
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:42
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/52; H01J61/523
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
30 words
A lamp as defined in claim 1 wherein the heat shield is a metal or an alloy selected from the group consisting of niobium, titanium, tantalum, zirconium, molybdenum and tungsten.
Claim 2
Dependent Claim
29 words
A lamp as defined in claim 1 wherein both of said closures comprise metal end caps and said heat shield is provided around each end of said ceramic tube.
Claim 3
Dependent Claim
28 words
A lamp as defined in claim 1 wherein said heat shield extends from said end cap a distance no greater than the outside diameter of said ceramic tube.
Claim 4
Dependent Claim
28 words
A lamp as defined in claim 1 wherein said heat shield has an axially extending tab bent around the metal end cap to lock the shield in place.
Claim 5
Dependent Claim
29 words
A lamp as defined in claim 1 wherein said ceramic tube is alumina, and said end cap, said exhaust tube and said heat shield are all made of niobium.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |