Patent US3672790A successfully refreshed from Google Patents.
US3672790A
Expired / Lapsed
US
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Air lift pump
Assignee: Berkeley Steel Construction Co
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Filing: 1971-04-15
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Granted: 1972-06-27
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Expires: 1991-04-15
Abstract
Abstract AN AIR LIFT PUMP FOR USE AS A SEWAGE LIFT PUMP IS PROVIDED WITH AN AIR INJECTION SECTION IN WHICH JET NOZZLES ARE DISPOSED PERIPHERALLY AND HELICALLY AROUND THE PUMP SECTION AND ARRANGED AT ANGLES TO THE PLANES RADIAL AND TANGENTIAL TO THE LONGITUDINAL AXIS OF THE PUMP WHICH VARY WHEN PROGRESSING PERIPHERALLY AROUND THE PUMP SECTION.
Inventors
- 👤 Jessie N White
- 👤 Bernard Roseby
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:19
CPC Classifications
F; F04; F04F; F04F5/00; F04F5/42
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) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |