Patent US3302177A successfully refreshed from Google Patents.
Patent US2535757A successfully refreshed from Google Patents.
US2535757A
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US
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Peripherally driven electroacoustical transducer
Assignee: Individual
•
Filing: 1946-06-25
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Granted: 1950-12-26
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Expires: 1966-06-25
Abstract
No abstract record available.
Inventors
- 👤 John J Root
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:22
CPC Classifications
H; H04; H04R; H04R13/00; H04R11/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2171733A
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US2223496A
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US2506609A
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US2506624A
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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) | 1953-12-25 | 1954-06-26 | 1954-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-12-25 | 1958-06-26 | 1958-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-12-25 | 1962-06-26 | 1962-12-26 | $7700.00 | Window Closed / Lapsed |