US3708351A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Blackening process
Assignee: Tubal Ind Inc
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Filing: 1970-02-02
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Granted: 1973-01-02
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Expires: 1990-02-02
Abstract
Abstract TELEVISION TUBE APERTURE MASKS AND SHADOW MASKS MADE OF STEEL ARE BLACKENED WITH AN ADHERENT OXIDE COATING BY HEATING THE MASKS IN AN OXIDIZING ATMOSPHERE MADE PRINCIPALLY OF COMBUSTION GASES. THE COMPOSITION OF THE OXIDIZING ATMOSPHERE IS CONTROLLED TO PROVIDE A MINOR AMOUNT OF FREE OXYGEN AND A MINOR AMOUNT OF LIVE STEAM D R A W I N G
Inventors
- 👤 N Dallas
- 👤 R Uzumecki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:46
CPC Classifications
C; C23; C23C; C23C8/00; C23C8/06; C23C8/08; C23C8/10
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-02 | 1976-07-03 | 1977-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-02 | 1980-07-03 | 1981-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-02 | 1984-07-03 | 1985-01-02 | $7700.00 | Window Closed / Lapsed |