US2221591A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency measuring apparatus
Assignee: The Echlin Manufacturing Co
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Filing: 1939-05-01
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Granted: 1940-11-12
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Expires: 1959-05-01
Abstract
No abstract record available.
Inventors
- 👤 Ben C Lansdale
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 16:05
CPC Classifications
G; G01; G01P; G01P3/00; G01P3/42; G01P3/44; G01P3/48; G01P3/4802; G01P3/4807; G01R; G01R23/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1943-11-12 | 1944-05-13 | 1944-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1947-11-12 | 1948-05-13 | 1948-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1951-11-12 | 1952-05-13 | 1952-11-12 | $7700.00 | Window Closed / Lapsed |