Patent US2490993A successfully refreshed from Google Patents.
Patent US2720474A successfully refreshed from Google Patents.
US2720474A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coated electrodes for electron discharge devices
Assignee: Raytheon Co
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Filing: 1952-09-13
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Granted: 1955-10-11
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Expires: 1972-09-13
Abstract
No abstract record available.
Inventors
- 👤 Herman L Myers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:28
CPC Classifications
H; H01; H01J; H01J17/00; H01J17/02; H01J17/04; H01J17/06; H01J17/066; H01J2893/00; H01J2893/0064; H01J2893/0065; H01J2893/0066
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
49 words
AN ELECTRODE FOR A GASEOUS DISCHARGE DEVICE OF TANTALUM HAVING THEREON A SMOOTH EXTERNAL SURFACE OF TANTALUM CARBIDE FORMED IN SITU BY HEATING THE TANTALUM ELECTRODE IN A CARBONACEOUS SUBSTANCE AT 800* C. TO 1,000* C. FOR ABOUT ONE AND ONE-HALF HOURS, AND SUBSEQUENTLY SUBSTANTIALLY REMOVING ANY UNCOMBINED CARBON.
Claim 2
Dependent Claim
49 words
AN ELECTRODE FOR A GASEOUS DISCHARGE DEVICE OF TANTALUM HAVING THEREON A SMOOTH EXTERNAL SURFACE OF TANTALUM CARBIDE FORMED IN SITU BY HEATING THE TANTALUM ELECTRODE IN A CARBONACEOUS SUBSTANCE AT 800* C. TO 1,000* C. FOR ABOUT ONE AND ONE-HALF HOURS, AND SUBSEQUENTLY SUBSTANTIALLY REMOVING ANY UNCOMBINED CARBON.
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) | 1958-10-10 | 1959-04-11 | 1959-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-10-10 | 1963-04-11 | 1963-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-10-10 | 1967-04-11 | 1967-10-11 | $7700.00 | Window Closed / Lapsed |