US2925514A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermionic cathode
Assignee: US Philips Corp
•
Filing: 1953-04-08
•
Granted: 1960-02-16
•
Expires: 1973-04-08
Abstract
No abstract record available.
Inventors
- 👤 Lemmens Hendrikus Johannes
- 👤 Jansen Marinus Jacobus
- 👤 Haayman Pieter Willem
- 👤 Knippenberg Wilhelm Franciscus
- 👤 Linden Petrus Cornelis Van Der
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:17
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/13; H01J1/20; H01J1/28; H01J1/14
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
134 words
A CATHODE COMPRISING A STRUCTURE OF REFRACTORY METAL FORMING AN INTERNAL CAVITY, ONE WALL OF SAID STRUCTURE BEING POROUS, THE PORES OF SAID WALL CONSTITUTING THE LARGEST APERTURES CONNECTING THE CAVITY WITH AN EXTERIOR ELECTRONEMISSIVE SURFACE OF SAID CATHODE, A SUPPLY OF ALKALINE EARTH COMPOUNDS IN SAID CAVITY CONSISTING OF A COMPOUND FORMED OF AN ALKALINE EARTH OXIDE AND AN ACID-FORMING OXIDE, THE AMOUNT OF ALKALINE EARTH OXIDE NOT BEING IN EXCESS OF THE AMOUNT REQUIRED TO FORM A DEFINITE CHEMICAL COMPOUND WITH THE ACID-FORMING OXIDE, AND A NON-OXIDIC INORGANIC MATERIAL SELECTED FROM THE GROUP CONSISTING OF BORON, BORON CARBIDE, SILICON CARBIDE, A METAL CARBIDE, AND A METAL BORIDE DISPOSED IN REACTIVE RELATIONSHIP WITH THE SAID ALKALINE EARTH COMPOUNDS AND CAPABLE OF REACTING THEREWITH IN A MANNER PRINCIPALLY PRODUCTIVE OF FREE ALKALINE EARTH METAL.
Claim 2
Dependent Claim
134 words
A CATHODE COMPRISING A STRUCTURE OF REFRACTORY METAL FORMING AN INTERNAL CAVITY, ONE WALL OF SAID STRUCTURE BEING POROUS, THE PORES OF SAID WALL CONSTITUTING THE LARGEST APERTURES CONNECTING THE CAVITY WITH AN EXTERIOR ELECTRONEMISSIVE SURFACE OF SAID CATHODE, A SUPPLY OF ALKALINE EARTH COMPOUNDS IN SAID CAVITY CONSISTING OF A COMPOUND FORMED OF AN ALKALINE EARTH OXIDE AND AN ACID-FORMING OXIDE, THE AMOUNT OF ALKALINE EARTH OXIDE NOT BEING IN EXCESS OF THE AMOUNT REQUIRED TO FORM A DEFINITE CHEMICAL COMPOUND WITH THE ACID-FORMING OXIDE, AND A NON-OXIDIC INORGANIC MATERIAL SELECTED FROM THE GROUP CONSISTING OF BORON, BORON CARBIDE, SILICON CARBIDE, A METAL CARBIDE, AND A METAL BORIDE DISPOSED IN REACTIVE RELATIONSHIP WITH THE SAID ALKALINE EARTH COMPOUNDS AND CAPABLE OF REACTING THEREWITH IN A MANNER PRINCIPALLY PRODUCTIVE OF FREE ALKALINE EARTH METAL.
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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) | 1963-02-15 | 1963-08-17 | 1964-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-02-15 | 1967-08-17 | 1968-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-02-15 | 1971-08-17 | 1972-02-16 | $7700.00 | Window Closed / Lapsed |