Patent US3521820A successfully refreshed from Google Patents.
US3521820A
Expired / Lapsed
US
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Hydraulic pulsed jet device
Assignee: Exotech Inc
•
Filing: 1967-01-31
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Granted: 1970-07-28
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Expires: 1987-01-31
Abstract
No abstract record available.
Inventors
- 👤 William C Cooley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:49
CPC Classifications
B; B05; B05B; B05B12/00; B05B12/02; B05B12/06; B26; B26F; B26F3/00; B26F3/004
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3412554A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-07-27 | 1974-01-26 | 1974-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-07-27 | 1978-01-26 | 1978-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-07-27 | 1982-01-26 | 1982-07-28 | $7700.00 | Window Closed / Lapsed |