Patent US2848644A successfully refreshed from Google Patents.
US2848644A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermionic cathode
Assignee: US Philips Corp
•
Filing: 1953-01-19
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Granted: 1958-08-19
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Expires: 1973-01-19
Abstract
No abstract record available.
Inventors
- 👤 Otto G Koppius
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:32
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/13; H01J1/20; H01J1/28
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
45 words
A THERMIONIC DISPENSER CATHODE COMPRISING A BODY OF REFRACTORY METAL HAVING A POROUS PORTION, AND A SUPPLY WITHIN SAID BODY OF A MIXTURE OF AN ALKALINE EARTH METAL TUNGSTATE AND A REFRACTORY METAL DIFFERENT FROM THAT OF SAID BODY AND SELECTED FROM THE GROUP CONSISTING
Claim 2
Dependent Claim
45 words
A THERMIONIC DISPENSER CATHODE COMPRISING A BODY OF REFRACTORY METAL HAVING A POROUS PORTION, AND A SUPPLY WITHIN SAID BODY OF A MIXTURE OF AN ALKALINE EARTH METAL TUNGSTATE AND A REFRACTORY METAL DIFFERENT FROM THAT OF SAID BODY AND SELECTED FROM THE GROUP CONSISTING
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-08-18 | 1962-02-17 | 1962-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-08-18 | 1966-02-17 | 1966-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-08-18 | 1970-02-17 | 1970-08-19 | $7700.00 | Window Closed / Lapsed |