Patent US3780648A successfully refreshed from Google Patents.
Patent US3597674A successfully refreshed from Google Patents.
Patent US2550860A successfully refreshed from Google Patents.
US2550860A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coded track circuit signaling system
Assignee: SPX Technologies Inc
•
Filing: 1947-03-06
•
Granted: 1951-05-01
•
Expires: 1967-03-06
Abstract
No abstract record available.
Inventors
- 👤 Neil D Preston
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 08:17
CPC Classifications
B; B61; B61L; B61L23/00; B61L23/08; B61L23/14; B61L23/16; B61L23/168
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-04-30 | 1954-10-30 | 1955-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-04-30 | 1958-10-30 | 1959-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-04-30 | 1962-10-30 | 1963-05-01 | $7700.00 | Window Closed / Lapsed |