US2848644A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermionic cathode
Assignee: US Philips Corp
•
Filing: 1953-01-19
•
Granted: 1958-08-19
•
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 11:32
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
References Cited (Backward Citations)
US1922244A
Cited
US2175345A
Cited
US2147447A
Cited
US2501089A
Cited
US2543728A
Cited
US2524001A
Cited
US2624024A
Cited
US2647216A
Cited
US2700118A
Cited
US2716716A
Cited
US2722626A
Cited
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 |