US2587481A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electron compass
Assignee: Individual
•
Filing: 1944-03-30
•
Granted: 1952-02-26
•
Expires: 1964-03-30
Abstract
No abstract record available.
Inventors
- 👤 Frank J Kaehni
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:38
CPC Classifications
G; G01; G01C; G01C17/00; G01C17/02; G01C17/28; G01C17/32
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2197042A
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US2444435A
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US2392370A
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US2406277A
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US2448527A
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US2439786A
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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) | 1955-02-25 | 1955-08-27 | 1956-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-02-25 | 1959-08-27 | 1960-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-02-25 | 1963-08-27 | 1964-02-26 | $7700.00 | Window Closed / Lapsed |