US2104433A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Acoustic device
Assignee: AT&T Inc
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Filing: 1934-04-25
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Granted: 1938-01-04
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Expires: 1954-04-25
Abstract
No abstract record available.
Inventors
- 👤 Robert N Marshall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:27
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/22; H04R1/28; H04R1/2807; H04R1/2815; H04R1/2819
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1941-01-03 | 1941-07-05 | 1942-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1945-01-03 | 1945-07-05 | 1946-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1949-01-03 | 1949-07-05 | 1950-01-04 | $7700.00 | Window Closed / Lapsed |