US2520646A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electroacoustic transducer
Assignee: AT&T Inc
•
Filing: 1948-09-09
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Granted: 1950-08-29
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Expires: 1968-09-09
Abstract
No abstract record available.
Inventors
- 👤 Edward E Mott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:32
CPC Classifications
H; H04; H04R; H04R11/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-08-28 | 1954-02-27 | 1954-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-08-28 | 1958-02-27 | 1958-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-08-28 | 1962-02-27 | 1962-08-29 | $7700.00 | Window Closed / Lapsed |