US1958620A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Piezo-electric crystals having low temperature coefficients of frequency
Assignee: AT&T Inc
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Filing: 1929-04-02
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Granted: 1934-05-15
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Expires: 1949-04-02
Abstract
No abstract record available.
Inventors
- 👤 Raymond A Heising
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 19:15
CPC Classifications
H; H03; H03H; H03H3/00; H03H3/007; H03H3/02; H03H3/04; H03H9/00; H03H9/15; H03H9/17; H03H9/19
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) | 1937-05-14 | 1937-11-13 | 1938-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1941-05-14 | 1941-11-13 | 1942-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1945-05-14 | 1945-11-13 | 1946-05-15 | $7700.00 | Window Closed / Lapsed |