Patent US2657320A successfully refreshed from Google Patents.
US2657320A
Expired / Lapsed
US
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Piezoelectric crystal unit
Assignee: AT&T Inc
•
Filing: 1948-12-30
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Granted: 1953-10-27
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Expires: 1968-12-30
Abstract
No abstract record available.
Inventors
- 👤 Arthur W Ziegler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:43
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/02; H03H9/05; H03H9/0504; H03H9/0533
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1766042A
Cited
US1648256A
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US1746788A
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US2077204A
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US2194418A
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US2275122A
Cited
US2474241A
Cited
US2453435A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-10-26 | 1957-04-27 | 1957-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-10-26 | 1961-04-27 | 1961-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-10-26 | 1965-04-27 | 1965-10-27 | $7700.00 | Window Closed / Lapsed |