Patent US2640889A successfully refreshed from Google Patents.
US2640889A
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Piezoelectric transducer
Assignee: Zenith Electronics LLC
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Filing: 1949-05-17
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Granted: 1953-06-02
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Expires: 1969-05-17
Abstract
No abstract record available.
Inventors
- 👤 Jr Walter L Cherry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:49
CPC Classifications
H; H04; H04R; H04R17/00; Y; Y10; Y10S; Y10S310/00; Y10S310/80
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2105010A
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US2242756A
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US2484950A
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US2479926A
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US2479987A
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US2540194A
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US2515446A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-06-01 | 1956-12-01 | 1957-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-06-01 | 1960-12-01 | 1961-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-06-01 | 1964-12-01 | 1965-06-02 | $7700.00 | Window Closed / Lapsed |