US2472714A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Piezoelectric sound pressure microphone
Assignee: Individual
•
Filing: 1945-04-16
•
Granted: 1949-06-07
•
Expires: 1965-04-16
Abstract
No abstract record available.
Inventors
- 👤 Massa Frank
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:58
CPC Classifications
H; H04; H04R; H04R17/00; Y; Y10; Y10T; Y10T29/00; Y10T29/42
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
DE477740C
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US1813461A
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US1939302A
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US2138036A
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US2181132A
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US2096826A
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US2393429A
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US2388242A
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US2405604A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1952-06-06 | 1952-12-06 | 1953-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1956-06-06 | 1956-12-06 | 1957-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1960-06-06 | 1960-12-06 | 1961-06-07 | $7700.00 | Window Closed / Lapsed |