Patent US3649411A successfully refreshed from Google Patents.
US2908865A
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US
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Frequency measuring apparatus
Assignee: Westinghouse Air Brake Co
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Filing: 1956-05-02
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Granted: 1959-10-13
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Expires: 1976-05-02
Abstract
No abstract record available.
Inventors
- 👤 Richard D Campbell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:18
CPC Classifications
G; G01; G01R; G01R23/00; G01R23/02; G01R23/06; G01R23/09
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2218642A
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US2307316A
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US2403557A
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US2555865A
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US2629008A
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US2755380A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-10-12 | 1963-04-13 | 1963-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-10-12 | 1967-04-13 | 1967-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-10-12 | 1971-04-13 | 1971-10-13 | $7700.00 | Window Closed / Lapsed |