US2816218A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control of manual block signal by a multiple frequency carrier system
Assignee: SPX Technologies Inc
•
Filing: 1952-03-29
•
Granted: 1957-12-10
•
Expires: 1972-03-29
Abstract
No abstract record available.
Inventors
- 👤 Frank X Rees
- 👤 Frederick W Brixner
- 👤 William M Barker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:38
CPC Classifications
B; B61; B61L; B61L7/00; B61L7/06; B61L7/08; B61L7/083
Claims Analysis
Total Claims: 0
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-12-09 | 1961-06-10 | 1961-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-12-09 | 1965-06-10 | 1965-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-12-09 | 1969-06-10 | 1969-12-10 | $7700.00 | Window Closed / Lapsed |