US2857461A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Speaker diaphragm controlled capacitor for negative feedback control
Assignee: Northrop Grumman Space and Mission Systems Corp
•
Filing: 1954-09-03
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Granted: 1958-10-21
•
Expires: 1974-09-03
Abstract
No abstract record available.
Inventors
- 👤 George H Brodie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:09
CPC Classifications
H; H04; H04R; H04R3/00; H04R3/002; H03; H03F; H03F1/00; H03F1/34; H03F1/36
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1772198A
Cited
US1689564A
Cited
US1822758A
Cited
US2145288A
Cited
US2194175A
Cited
US2352711A
Cited
US2485405A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-10-20 | 1962-04-21 | 1962-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-10-20 | 1966-04-21 | 1966-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-10-20 | 1970-04-21 | 1970-10-21 | $7700.00 | Window Closed / Lapsed |