Patent US2342822A successfully refreshed from Google Patents.
US2342822A
Expired / Lapsed
US
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Amplifying system
Assignee: AT&T Inc
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Filing: 1940-12-24
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Granted: 1944-02-29
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Expires: 1960-12-24
Abstract
No abstract record available.
Inventors
- 👤 Carl H Rumpel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:35
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/06; H04B1/16; H04B1/1607; H04B1/1623; H03; H03F; H03F1/00; H03F1/34; H03F1/36; H03G; H03G3/00; H03G3/02; H03G3/04; H03G3/06; H03G3/08; H04R; H04R25/00
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) | 1947-02-28 | 1947-08-30 | 1948-02-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1951-02-28 | 1951-08-30 | 1952-02-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1955-02-28 | 1955-08-30 | 1956-02-29 | $7700.00 | Window Closed / Lapsed |