Patent US2212337A successfully refreshed from Google Patents.
US2212337A
Expired / Lapsed
US
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Electron discharge device circuit
Assignee: AT&T Inc
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Filing: 1939-01-27
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Granted: 1940-08-20
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Expires: 1959-01-27
Abstract
No abstract record available.
Inventors
- 👤 Sherman T Brewer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:11
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/26; H03F3/28; H03F1/00; H03F1/34; H03F1/36; H03G; H03G3/00; H03G3/02; H03G3/04; H03G3/06; H03G3/08; H03G7/00; H03G7/02; H03G7/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1943-08-20 | 1944-02-19 | 1944-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1947-08-20 | 1948-02-19 | 1948-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1951-08-20 | 1952-02-19 | 1952-08-20 | $7700.00 | Window Closed / Lapsed |