Patent US2530824A successfully refreshed from Google Patents.
US2530824A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Secret carrier signaling method and system
Assignee: AT&T Inc
•
Filing: 1946-08-20
•
Granted: 1950-11-21
•
Expires: 1966-08-20
Abstract
No abstract record available.
Inventors
- 👤 Kenneth L King
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:59
CPC Classifications
H; H04; H04K; H04K1/00; H04K1/04
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US1464096A
Cited
US1592940A
Cited
US1624601A
Cited
US1762984A
Cited
US1992441A
Cited
US2179106A
Cited
US2407260A
Cited
US2405599A
Cited
US2411206A
Cited
US2393224A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-11-20 | 1954-05-22 | 1954-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-11-20 | 1958-05-22 | 1958-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-11-20 | 1962-05-22 | 1962-11-21 | $7700.00 | Window Closed / Lapsed |