US3902091A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Incandescent lamp
Assignee: Thorn Lighting Ltd
•
Filing: 1974-01-18
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Granted: 1975-08-26
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Expires: 1994-01-18
Abstract
Abstract Tungsten-halogen lamps of extended life are obtained by coating internal surfaces of the discharge tube and exposed surfaces of internal components with metal phosphate or arsenate glasses. The preferred glass is aluminium titanium phosphate. The coatings may be formed by applying a liquid composition capable of generating the desired phosphate or arsenate to the surfaces to be coated, and subsequently heating them to remove the liquid medium and form a vitreous coating. The medium may be water or an organic solvent such as an alcohol, and may contain a dissolved compound of the metal and an oxyacid of phosphorus or arsenic.
Inventors
- 👤 David Robert Mason
- 👤 Susan Margaret Cole
- 👤 John Michael Rees
- 👤 James Richard Coaton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 09:08
CPC Classifications
H; H01; H01K; H01K3/00; H01K1/00; H01K1/28; H01K1/32
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
72 words
A TUNGSTEN-HALOGEN LAMP COMPRISING: A LIGHT-TRANSMITTING ENVELOPE, INTERNAL COMPONENTS INCLUDING A TUNGSTEN FILAMENT AND SUPPORTS THEREFOR SEALED WITHIN SAID ENVELOPE, ELECTRICAL LEADS FOR SAID FILAMENT SEALED INTO SAID ENVELOPE, A GASEOUS FILL INCLUDING HALOGEN IN SAID ENVELOPE, AND A HOMOGENEOUS, DEFECT-FREE PROTECTIVE COATING OF A METAL PHOSPHATE OR ARSENATE GLASS ON AT LEAST THE INTERNAL SURFACE OF THE ENVELOPE AND THE EXPOSED SURFACES OF INTERNAL COMPONENTS OTHER THAN INCANDESCENT PORTIONS OF SAID
Claim 2
Dependent Claim
72 words
A TUNGSTEN-HALOGEN LAMP COMPRISING: A LIGHT-TRANSMITTING ENVELOPE, INTERNAL COMPONENTS INCLUDING A TUNGSTEN FILAMENT AND SUPPORTS THEREFOR SEALED WITHIN SAID ENVELOPE, ELECTRICAL LEADS FOR SAID FILAMENT SEALED INTO SAID ENVELOPE, A GASEOUS FILL INCLUDING HALOGEN IN SAID ENVELOPE, AND A HOMOGENEOUS, DEFECT-FREE PROTECTIVE COATING OF A METAL PHOSPHATE OR ARSENATE GLASS ON AT LEAST THE INTERNAL SURFACE OF THE ENVELOPE AND THE EXPOSED SURFACES OF INTERNAL COMPONENTS OTHER THAN INCANDESCENT PORTIONS OF SAID
Claim 3
Dependent Claim
21 words
A lamp according to claim 1 wherein said gaseous fill comprises a fluorine-supplying material selected from elemental fluorine and fluorine-containing compounds.
Claim 4
Dependent Claim
32 words
A lamp according to claim 1 wherein said coating comprises a glass selected from phosphate and arsenate glasses of at least one of the metals aluminium, iron, chromium titanium, vanadium and tin.
Claim 5
Dependent Claim
15 words
A lamp according to claim 2 wherein said coating comprises an aluminium titanium phosphate glass.
Claim 6
Dependent Claim
25 words
A lamp according to claim 3 wherein the atomic ratio of metal to phosphorus or arsenic in the glass composition is from 1:0.1 to 1:2.9.
Claim 7
Dependent Claim
27 words
A lamp according to claim 1 wherein said coating is the deposited and baked residue of a solution of a solvent-soluble complex phosphate containing coordinated solvent groups.
References Cited (Backward Citations)
US2030397A
Cited
US2393469A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-25 | 1979-02-24 | 1979-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-25 | 1983-02-24 | 1983-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-25 | 1987-02-24 | 1987-08-26 | $7700.00 | Window Closed / Lapsed |