US4288713A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lamp having opaque coating
Assignee: Osram Sylvania Inc
•
Filing: 1979-11-23
•
Granted: 1981-09-08
•
Expires: 1999-11-23
Abstract
Abstract An incandescent lamp has on a portion of the lamp envelope a dark coating comprising manganese dioxide and aluminum phosphate.
Inventors
- 👤 Richard C. Marlor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:53
CPC Classifications
H; H01; H01K; H01K1/00; H01K1/28; H01K1/32
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
45 words
In an incandescent lamp including at least one tungsten filament disposed within a glass envelope, the improvement comprising an opaque coating on a portion of the envelope for preventing transmission of light therethrough, the coating comprising a dark mixture of manganese dioxide and aluminum phosphate.
Claim 2
Dependent Claim
45 words
In an incandescent lamp including at least one tungsten filament disposed within a glass envelope, the improvement comprising an opaque coating on a portion of the envelope for preventing transmission of light therethrough, the coating comprising a dark mixture of manganese dioxide and aluminum phosphate.
Claim 3
Dependent Claim
11 words
The lamp of claim 1 wherein said mixture includes kaolin clay.
Claim 4
Dependent Claim
11 words
The lamp of claim 1 wherein said mixture includes boric acid.
Claim 5
Dependent Claim
16 words
The lamp of claim 1 wherein said dark mixture additionally includes kaolin clay and boric acid.
Claim 6
Dependent Claim
24 words
The lamp of claim 1 wherein said opaque coating is applied by dipping said envelope portion into an aqueous suspension containing said dark mixture.
Claim 7
Dependent Claim
17 words
The lamp of claim 5 wherein said aqueous suspension contains, in addition, kaolin clay and boric acid.
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) | 1984-09-07 | 1985-03-09 | 1985-09-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-07 | 1989-03-09 | 1989-09-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-07 | 1993-03-09 | 1993-09-08 | $7700.00 | Window Closed / Lapsed |