Patent CH120378A successfully refreshed from Google Patents.
US2843671A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Feed back amplifiers
Assignee: David Bogen & Co Inc
•
Filing: 1954-05-19
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Granted: 1958-07-15
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Expires: 1974-05-19
Abstract
No abstract record available.
Inventors
- 👤 Charles A Wilkins
- 👤 Herbert W Sullivan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 04:24
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/34; H03F1/36
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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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) | 1961-07-14 | 1962-01-13 | 1962-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-07-14 | 1966-01-13 | 1966-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-07-14 | 1970-01-13 | 1970-07-15 | $7700.00 | Window Closed / Lapsed |