US2194539A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Piezoelectric crystal impedance element
Assignee: AT&T Inc
•
Filing: 1938-09-03
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Granted: 1940-03-26
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Expires: 1958-09-03
Abstract
No abstract record available.
Inventors
- 👤 Joseph F Barry
- 👤 Henry G Och
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:06
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/0023; H03H9/0095; H03H9/46; H03H9/54; H03H9/542; H03H9/56; H03H9/566; Y; Y10; Y10T; Y10T29/00; Y10T29/42
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) | 1943-03-26 | 1943-09-25 | 1944-03-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1947-03-26 | 1947-09-25 | 1948-03-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1951-03-26 | 1951-09-25 | 1952-03-26 | $7700.00 | Window Closed / Lapsed |