Patent US3201639A successfully refreshed from Google Patents.
US3201639A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermionic dispenser cathode
Assignee: US Philips Corp
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Filing: 1963-02-07
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Granted: 1965-08-17
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Expires: 1983-02-07
Abstract
No abstract record available.
Inventors
- 👤 Levi Roberto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:32
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/13; H01J1/20; H01J1/28
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
136 words
A THERMIONIC DISPENSER CATHODE COMPRISING A POROUS BODY OF REFRACTORY METAL HAVING AT LEAST ONE SURFACE PORTION ADAPTED TO ACT AS AN ELECTRON-EMISSIVE SURFACE AND PROVIDED WITH A LARGE NUMBER OF SMALL PASSAGEWAYS CONNECTING THE INTERIOR OF SAID BODY TO SAID SURFACE, AND A BARIUM-PRODUCING MATERIAL DISPERSED WITHIN SAID BODY AND CONSTITUTED BY A FUSED MIXTURE OF BARIUM OXIDE, AT LEAST ONE OXIDE SELECTED FROM THE GROUP CONSISTING OF ALUMINUM OXIDE AND BORON OXIDE, THE MOLE RATIO OF BARIUM OXIDE TO SAID LATTER OXIDE BEING IN EXCESS OF 1:1, AND AN EMISSION-ENHANCING ADDITIVE CONSTITUTED BY AN OXIDE OF AN ALKALINE EARTH METAL OTHER THAN BARIUM, SAID ADDITIVE OXIDE BEING PRESENT IN AN AMOUNT AT WHICH THE CATHODE HAS AN EMISSION AT ZERO FIELD AT LEAST TWICE THAT OF A SIMILARLY CONSTITUTED CATHODE WITHOUT SAID ADDITIVE OXIDE.
Claim 2
Dependent Claim
136 words
A THERMIONIC DISPENSER CATHODE COMPRISING A POROUS BODY OF REFRACTORY METAL HAVING AT LEAST ONE SURFACE PORTION ADAPTED TO ACT AS AN ELECTRON-EMISSIVE SURFACE AND PROVIDED WITH A LARGE NUMBER OF SMALL PASSAGEWAYS CONNECTING THE INTERIOR OF SAID BODY TO SAID SURFACE, AND A BARIUM-PRODUCING MATERIAL DISPERSED WITHIN SAID BODY AND CONSTITUTED BY A FUSED MIXTURE OF BARIUM OXIDE, AT LEAST ONE OXIDE SELECTED FROM THE GROUP CONSISTING OF ALUMINUM OXIDE AND BORON OXIDE, THE MOLE RATIO OF BARIUM OXIDE TO SAID LATTER OXIDE BEING IN EXCESS OF 1:1, AND AN EMISSION-ENHANCING ADDITIVE CONSTITUTED BY AN OXIDE OF AN ALKALINE EARTH METAL OTHER THAN BARIUM, SAID ADDITIVE OXIDE BEING PRESENT IN AN AMOUNT AT WHICH THE CATHODE HAS AN EMISSION AT ZERO FIELD AT LEAST TWICE THAT OF A SIMILARLY CONSTITUTED CATHODE WITHOUT SAID ADDITIVE 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) | 1968-08-16 | 1969-02-15 | 1969-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-08-16 | 1973-02-15 | 1973-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-08-16 | 1977-02-15 | 1977-08-17 | $7700.00 | Window Closed / Lapsed |