US2695399A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Means for detecting energy of predetermined frequencies in electrical systems
Assignee: Westinghouse Air Brake Co
•
Filing: 1952-03-14
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Granted: 1954-11-23
•
Expires: 1972-03-14
Abstract
No abstract record available.
Inventors
- 👤 Paul N Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:08
CPC Classifications
B; B61; B61L; B61L23/00; B61L23/08; B61L23/14; B61L23/16; B61L23/168
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2198901A
Cited
US2420232A
Cited
US2455351A
Cited
US2460337A
Cited
US2461452A
Cited
US2454687A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-11-22 | 1958-05-24 | 1958-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-11-22 | 1962-05-24 | 1962-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-11-22 | 1966-05-24 | 1966-11-23 | $7700.00 | Window Closed / Lapsed |