US2951973A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signalling system
Assignee: Individual
•
Filing: 1957-08-28
•
Granted: 1960-09-06
•
Expires: 1977-08-28
Abstract
No abstract record available.
Inventors
- 👤 Duane E Atkinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:51
CPC Classifications
G; G08; G08B; G08B27/00
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US2145053A
Cited
US2231174A
Cited
US2397539A
Cited
US2537998A
Cited
US2834879A
Cited
US2722677A
Cited
US2852622A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-09-06 | 1964-03-07 | 1964-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-09-06 | 1968-03-07 | 1968-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-09-06 | 1972-03-07 | 1972-09-06 | $7700.00 | Window Closed / Lapsed |