Patent US3305481A successfully refreshed from Google Patents.
US3305481A
Expired / Lapsed
US
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Ultrasonic sieving
Assignee: University of California Berkeley
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Filing: 1964-12-14
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Granted: 1967-02-21
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Expires: 1984-12-14
Abstract
No abstract record available.
Inventors
- 👤 Melvin N A Peterson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:12
CPC Classifications
B; B01; B01D; B01D35/00; B01D35/20; G; G01; G01N; G01N15/00; G01N15/06; G01N15/0606; G01N15/0618; B07; B07B; B07B2230/00; B07B2230/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-02-20 | 1970-08-22 | 1971-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-02-20 | 1974-08-22 | 1975-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-02-20 | 1978-08-22 | 1979-02-21 | $7700.00 | Window Closed / Lapsed |