US2830201A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electro-acoustic transducer with acoustic coupling means
Assignee: Kelvin Hughes Ltd
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Filing: 1951-10-30
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Granted: 1958-04-08
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Expires: 1971-10-30
Abstract
No abstract record available.
Inventors
- 👤 Wilson Robert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 03:16
CPC Classifications
G; G01; G01N; G01N29/00; G01N29/22; G01N29/28
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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GB469018A
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US2458581A
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US2702764A
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US2650185A
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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) | 1961-04-07 | 1961-10-07 | 1962-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-04-07 | 1965-10-07 | 1966-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-04-07 | 1969-10-07 | 1970-04-08 | $7700.00 | Window Closed / Lapsed |