Patent US3211939A successfully refreshed from Google Patents.
US3211939A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electron tube having close spaced electrodes and a bimetallic cathode
Assignee: Varian Medical Systems Inc
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Filing: 1961-07-31
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Granted: 1965-10-12
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Expires: 1981-07-31
Abstract
No abstract record available.
Inventors
- 👤 John F Richter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:24
CPC Classifications
G; G21; G21C; G21C17/00; G21C17/14; G21D; G21D3/00; G21D3/04; H; H01; H01J; H01J1/00; H01J1/02; H01J1/13; H01J1/20; Y; Y02; Y02E; Y02E30/00; Y02E30/30
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
128 words
AN ELECTRON TUBE COMPRISING A HERMETICALLY SEALED ENVELOPE AND AT LEAST TWO ELECTRODES WITHIN SAID ENVELOPE, ONE OF SAID ELECTRODES BEING A DISK-SHAPED CATHODE HAVING AN ELECTRON EMITTING SURFACE POSITIONED CLOSE TO ANOTHER OF SAID ELECTRODES, SAID OTHER ELECTRODE BEING A PLANAR ELECTRODE, A RING OF BRAZING MATERIAL BRAZED TO SAID CATHODE OUTWARDLY OF THE CENTER OF THE CATHODE, SAID BRAZING RING BEING MADE OF A MATERIAL WHICH FORMS AN ALLOY WITH THE MATERIAL OF SAID CATHODE, SAID ALLOY HAVING A COEFFICIENT OF EXPANSION DIFFERENT FROM THAT OF SAID CATHODE AND A MELTING POINT ABOVE THE OPERATING TEMPERATURE OF SAID CATHODE, AND THE CENTER PORTION OF SAID CATHODE BEING DEFORMED RELATIVE TO THE PERIPHERY OF THE CATHODE BY SAID ALLOY IN A DIRECTION AWAY FROM SAID OTHER ELECTRODE.
Claim 2
Dependent Claim
128 words
AN ELECTRON TUBE COMPRISING A HERMETICALLY SEALED ENVELOPE AND AT LEAST TWO ELECTRODES WITHIN SAID ENVELOPE, ONE OF SAID ELECTRODES BEING A DISK-SHAPED CATHODE HAVING AN ELECTRON EMITTING SURFACE POSITIONED CLOSE TO ANOTHER OF SAID ELECTRODES, SAID OTHER ELECTRODE BEING A PLANAR ELECTRODE, A RING OF BRAZING MATERIAL BRAZED TO SAID CATHODE OUTWARDLY OF THE CENTER OF THE CATHODE, SAID BRAZING RING BEING MADE OF A MATERIAL WHICH FORMS AN ALLOY WITH THE MATERIAL OF SAID CATHODE, SAID ALLOY HAVING A COEFFICIENT OF EXPANSION DIFFERENT FROM THAT OF SAID CATHODE AND A MELTING POINT ABOVE THE OPERATING TEMPERATURE OF SAID CATHODE, AND THE CENTER PORTION OF SAID CATHODE BEING DEFORMED RELATIVE TO THE PERIPHERY OF THE CATHODE BY SAID ALLOY IN A DIRECTION AWAY FROM SAID OTHER ELECTRODE.
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) | 1968-10-11 | 1969-04-12 | 1969-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-10-11 | 1973-04-12 | 1973-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-10-11 | 1977-04-12 | 1977-10-12 | $7700.00 | Window Closed / Lapsed |