Patent US2440089A successfully refreshed from Google Patents.
US2440089A
Expired / Lapsed
US
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Electron discharge device employing cavity resonators
Assignee: RCA Corp
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Filing: 1942-08-18
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Granted: 1948-04-20
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Expires: 1962-08-18
Abstract
No abstract record available.
Inventors
- 👤 Andrew V Haeff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:43
CPC Classifications
H; H01; H01J; H01J25/00; H01J25/02; H01J25/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2250511A
Cited
US2282295A
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US2284751A
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US2225447A
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US2304186A
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US2314794A
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US2311520A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-04-20 | 1951-10-20 | 1952-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-04-20 | 1955-10-20 | 1956-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-04-20 | 1959-10-20 | 1960-04-20 | $7700.00 | Window Closed / Lapsed |