US1746788A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Piezo-electric device
Assignee: AT&T Inc
•
Filing: 1928-12-21
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Granted: 1930-02-11
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Expires: 1948-12-21
Abstract
No abstract record available.
Inventors
- 👤 Warren A Marrison
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:35
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/15; H03H9/17
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) | 1933-02-10 | 1933-08-12 | 1934-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1937-02-10 | 1937-08-12 | 1938-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1941-02-10 | 1941-08-12 | 1942-02-11 | $7700.00 | Window Closed / Lapsed |