Patent US2557979A successfully refreshed from Google Patents.
US2557979A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency modulation
Assignee: STC PLC
•
Filing: 1948-02-06
•
Granted: 1951-06-26
•
Expires: 1968-02-06
Abstract
No abstract record available.
Inventors
- 👤 Labin Emile
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:33
CPC Classifications
H; H03; H03C; H03C3/00; H03C3/10; H03C3/28; H03C7/00; H03C7/02
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US2085406A
Cited
US2173234A
Cited
US2051537A
Cited
US2190515A
Cited
US2290587A
Cited
US2335659A
Cited
US2425657A
Cited
US2511106A
Cited
US2385086A
Cited
US2424357A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-06-25 | 1954-12-25 | 1955-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-06-25 | 1958-12-25 | 1959-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-06-25 | 1962-12-25 | 1963-06-26 | $7700.00 | Window Closed / Lapsed |