US2540139A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency controller
Assignee: Individual
•
Filing: 1945-03-09
•
Granted: 1951-02-06
•
Expires: 1965-03-09
Abstract
No abstract record available.
Inventors
- 👤 Richard H Ranger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:14
CPC Classifications
H; H03; H03C; H03C3/00; H03C3/02; H03C3/09
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1873842A
Cited
US1934000A
Cited
US2017894A
Cited
US2041855A
Cited
US2151127A
Cited
US2303654A
Cited
US2358454A
Cited
US2367868A
Cited
US2379689A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-02-05 | 1954-08-07 | 1955-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-02-05 | 1958-08-07 | 1959-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-02-05 | 1962-08-07 | 1963-02-06 | $7700.00 | Window Closed / Lapsed |