US2225312A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Acoustic device
Assignee: AT&T Inc
•
Filing: 1939-10-05
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Granted: 1940-12-17
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Expires: 1959-10-05
Abstract
No abstract record available.
Inventors
- 👤 Warren P Mason
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:00
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/32; H04R1/34; H04R1/342; G; G01; G01S; G01S1/00; G01S1/72; Y; Y10; Y10S; Y10S181/00; Y10S181/40
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) | 1943-12-17 | 1944-06-17 | 1944-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1947-12-17 | 1948-06-17 | 1948-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1951-12-17 | 1952-06-17 | 1952-12-17 | $7700.00 | Window Closed / Lapsed |