Patent US4112405A successfully refreshed from Google Patents.
Patent FR941828A successfully refreshed from Google Patents.
Patent US3588266A successfully refreshed from Google Patents.
US3588266A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low specific speed rotary pump
Assignee: Rolls Royce PLC
•
Filing: 1968-08-09
•
Granted: 1971-06-28
•
Expires: 1988-08-09
Abstract
Abstract MOUNTING SEVERAL BLUFF PROJECTIONS, SUCH AS CYLINDRICAL PINS, AT CIRCUMFERENTIALLY-SPACED POSITIONS AROUND THE IMPELLER OF A CENTRIFUGAL PUMP UPSTREAM OF THE INLET TO THE IMPELLER SUCH THAT WHEN THE PUMP IS OPERATED WITH A LOW FLOW INLET ANGLE AND AT A LOW SUCTION PRESSURE, EACH PROJECTION WILL PRODUCE A TRAILING CAVITY OF GAS OR VAPOR. THE TRAILING CAVITIES ARE OF HELICAL FORM AND BECOME ENTWINED WITH EACH OTHER IN THE IMPELLER INLET REGION AND PRODUCE A FLUID "BARRIER" WHICH TENDS TO REDUCE PREWHIRL CONDITIONS BY PREVENTING FEEDBACK OF LIQUID FROM THE IMPELLER IN AN UPSTREAM DIRECTION AND ALSO PRODUCES STABILITY OF FLOW THROUGH THE IMPELLER.
Inventors
- 👤 John Lanfear Scott-Scott
- 👤 David John Sweetland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:22
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/18; F04D29/22; F04D29/2261; F04D29/2277; F04D15/00; F04D15/0005; F04D15/0011; F04D9/00
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1974-06-27 | 1974-12-27 | 1975-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-27 | 1978-12-27 | 1979-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-27 | 1982-12-27 | 1983-06-28 | $7700.00 | Window Closed / Lapsed |