Patent US1918976A successfully refreshed from Google Patents.
US1918976A
Expired / Lapsed
US
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Piezo-electric crystals
Assignee: AT&T Inc
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Filing: 1930-06-06
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Granted: 1933-07-18
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Expires: 1950-06-06
Abstract
No abstract record available.
Inventors
- 👤 Warren A Marrison
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:08
CPC Classifications
H; H10; H10N; H10N30/00; H10N30/01; H10N30/08; H10N30/085; H10N30/088
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) | 1936-07-17 | 1937-01-16 | 1937-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1940-07-17 | 1941-01-16 | 1941-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1944-07-17 | 1945-01-16 | 1945-07-18 | $7700.00 | Window Closed / Lapsed |