US3450565A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of coating heater coils
Assignee: GTE Sylvania Inc
•
Filing: 1964-12-18
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Granted: 1969-06-17
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Expires: 1984-12-18
Abstract
No abstract record available.
Inventors
- 👤 James Theodosopoulos
- 👤 Stanley Mackay
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:39
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/40; H05B3/42; H01; H01J; H01J1/00; H01J1/02; H01J1/13; H01J1/20; H01J1/22; H01J9/00; H01J9/02; H01J9/08
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
93 words
IN THE PROCESS OF PREPARING HEATER COILS COATED WITH AN INSULATING OXIDE BUT HAVING UNCOATED ENDS, THE IMPROVEMENT COMPRISING: PREPARING A SOLUTION OF AT LEAST ONE MEMBER SELECTED FROM THE HETEROPOLY GROUP CONSISTING OF PHOSPHOTUNGSTIC ACID, ALUMINOTUNGSTIC ACID AND TUNGSTOSILICIC ACID; DIPPING SAID COATED HEATER INTO SAID SOLUTION TO A DEPTH SUFFICIENT TO LEAVE AN UNDIPPED GAP OF INSULATING OXIDE COATING AT THE ENDS THEREOF; AND FIRING SAID DIPPED COIL IN A REDUCING ATMOSPHERE UNDER CONDITIONS SUFFICIENT TO REDUCE SAID MEMBER TO TUNGSTEN METAL AND THEREBY DARKENING THE SURFACE OF SAID INSULATING COATING.
Claim 2
Dependent Claim
93 words
IN THE PROCESS OF PREPARING HEATER COILS COATED WITH AN INSULATING OXIDE BUT HAVING UNCOATED ENDS, THE IMPROVEMENT COMPRISING: PREPARING A SOLUTION OF AT LEAST ONE MEMBER SELECTED FROM THE HETEROPOLY GROUP CONSISTING OF PHOSPHOTUNGSTIC ACID, ALUMINOTUNGSTIC ACID AND TUNGSTOSILICIC ACID; DIPPING SAID COATED HEATER INTO SAID SOLUTION TO A DEPTH SUFFICIENT TO LEAVE AN UNDIPPED GAP OF INSULATING OXIDE COATING AT THE ENDS THEREOF; AND FIRING SAID DIPPED COIL IN A REDUCING ATMOSPHERE UNDER CONDITIONS SUFFICIENT TO REDUCE SAID MEMBER TO TUNGSTEN METAL AND THEREBY DARKENING THE SURFACE OF SAID INSULATING COATING.
References Cited (Backward Citations)
DE1090774B
Cited
US3195004A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-06-16 | 1972-12-16 | 1973-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-06-16 | 1976-12-16 | 1977-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-06-16 | 1980-12-16 | 1981-06-17 | $7700.00 | Window Closed / Lapsed |