Patent US2457527A successfully refreshed from Google Patents.
US2457527A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Acoustic device
Assignee: AT&T Inc
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Filing: 1942-10-02
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Granted: 1948-12-28
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Expires: 1962-10-02
Abstract
No abstract record available.
Inventors
- 👤 Bruce Edmond
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:48
CPC Classifications
G; G10; G10K; G10K11/00; G10K11/18; G10K11/26; G10K11/28; H; H04; H04R; H04R1/00; H04R1/20; H04R1/32; H04R1/34; H04R1/342
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1572387A
Cited
US1755636A
Cited
US1843524A
Cited
US1969704A
Cited
US2135840A
Cited
US2216949A
Cited
US2228024A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-12-28 | 1952-06-28 | 1952-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-12-28 | 1956-06-28 | 1956-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-12-28 | 1960-06-28 | 1960-12-28 | $7700.00 | Window Closed / Lapsed |