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US2820947A
Expired / Lapsed
US
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Electric field meter
Assignee: Individual
•
Filing: 1955-04-29
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Granted: 1958-01-21
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Expires: 1975-04-29
Abstract
No abstract record available.
Inventors
- 👤 Gunn Ross
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:48
CPC Classifications
G; G01; G01W; G01W1/00; G01W1/16
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1429227A
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US2181946A
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US2248405A
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US2400112A
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US2449068A
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US2516984A
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US2462172A
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US2490579A
Cited
US2662191A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-01-20 | 1961-07-22 | 1962-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-01-20 | 1965-07-22 | 1966-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-01-20 | 1969-07-22 | 1970-01-21 | $7700.00 | Window Closed / Lapsed |