Patent US2700000A successfully refreshed from Google Patents.
US2700000A
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Thermionic cathode and method of manufacturing same
Assignee: US Philips Corp
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Filing: 1952-02-27
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Granted: 1955-01-18
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Expires: 1972-02-27
Abstract
No abstract record available.
Inventors
- 👤 Levi Roberto
- 👤 Ray C Hughes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:46
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/02; H01J9/04; H01J9/042; H01J9/047; H01J1/00; H01J1/02; H01J1/13; H01J1/14; H01J1/20; H01J1/28
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
61 words
A METHOD OF MANUFACTURING A THERMIONIC CATHODE ADAPTED TO OPERATE AT ELEVATED TEMPERATURES WHICH COMPRISES FORMING A POROUS SINTERED BODY OF REFRACTORY METAL. AND IMPREGNATING THE PORES OF SAID BODY WITH A MOLTEN MIXTURE OF AN OXIDE SELECTED FROM THE GROUP CONSISTING OF ALUMINUM OXIDE, SILICON DIOXIDE, BORIC OXIDE, BERYLLIUM OXIDE AND A SUBSTANTIAL AMOUNT OF AN ALKALINE EARTH METAL OXIDE.
Claim 2
Independent Claim
61 words
A METHOD OF MANUFACTURING A THERMIONIC CATHODE ADAPTED TO OPERATE AT ELEVATED TEMPERATURES WHICH COMPRISES FORMING A POROUS SINTERED BODY OF REFRACTORY METAL. AND IMPREGNATING THE PORES OF SAID BODY WITH A MOLTEN MIXTURE OF AN OXIDE SELECTED FROM THE GROUP CONSISTING OF ALUMINUM OXIDE, SILICON DIOXIDE, BORIC OXIDE, BERYLLIUM OXIDE AND A SUBSTANTIAL AMOUNT OF AN ALKALINE EARTH METAL OXIDE.
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) | 1958-01-17 | 1958-07-19 | 1959-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-01-17 | 1962-07-19 | 1963-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-01-17 | 1966-07-19 | 1967-01-18 | $7700.00 | Window Closed / Lapsed |