Patent US2640191A successfully refreshed from Google Patents.
US2640191A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Combined radio direction and distance finding system
Assignee: International Standard Electric Corp
•
Filing: 1947-06-21
•
Granted: 1953-05-26
•
Expires: 1967-06-21
Abstract
No abstract record available.
Inventors
- 👤 Earp Charles Williams
- 👤 Cleaver Richard Francis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 08:39
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/74; G01S13/82; G01S13/84
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US1750668A
Cited
US2147810A
Cited
US2252083A
Cited
US2198113A
Cited
US2268643A
Cited
US2582971A
Cited
US2248727A
Cited
US2409448A
Cited
US2449985A
Cited
US2405238A
Cited
US2468032A
Cited
US2400641A
Cited
US2406953A
Cited
US2471516A
Cited
US2426217A
Cited
US2467299A
Cited
US2427220A
Cited
US2433341A
Cited
US2529510A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-05-25 | 1956-11-24 | 1957-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-05-25 | 1960-11-24 | 1961-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-05-25 | 1964-11-24 | 1965-05-26 | $7700.00 | Window Closed / Lapsed |