Patent US2639399A successfully refreshed from Google Patents.
US2639399A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electron emitter
Assignee: General Electric Co
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Filing: 1950-03-31
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Granted: 1953-05-19
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Expires: 1970-03-31
Abstract
No abstract record available.
Inventors
- 👤 James M Lafferty
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:03
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/13; H01J1/14; H01J1/148; C; C25; C25C; C25C7/00; C25C7/02; H01J17/00; H01J17/02; H01J17/04; H01J17/06; H01J17/066; H01J2893/00; H01J2893/0064; H01J2893/0065; H01J2893/0066
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
45 words
A CATHODE COMPRISING A CONDUCTIVE SUPPORT PROVIDING A HEATER AND A COATING COMPRISING AS THE ESSENTIAL INGREDIENT THEREOF AT LEAST ONE METALAL BORIDE, THE BORIDES BEING SELECTED FROM THE GROUP CONSISTING OF THE BORIDES OF BARIUM, STRONTIUM, CALCIUM, THORIUM, URANIUM AND THE RARE EARTH METALS.
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) | 1956-05-18 | 1956-11-17 | 1957-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-05-18 | 1960-11-17 | 1961-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-05-18 | 1964-11-17 | 1965-05-19 | $7700.00 | Window Closed / Lapsed |