US2924753A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical protective relay systems
Assignee: English Electric Co Ltd
•
Filing: 1956-05-14
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Granted: 1960-02-09
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Expires: 1976-05-14
Abstract
No abstract record available.
Inventors
- 👤 Smith John Walter Freeman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 19:31
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/40
Claims Analysis
Total Claims: 0
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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) | 1963-02-08 | 1963-08-10 | 1964-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-02-08 | 1967-08-10 | 1968-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-02-08 | 1971-08-10 | 1972-02-09 | $7700.00 | Window Closed / Lapsed |