Patent US3291067A successfully refreshed from Google Patents.
US3291067A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydrostatic power transmission
Assignee: Boulton Paul Aircraft Ltd
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Filing: 1965-02-24
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Granted: 1966-12-13
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Expires: 1985-02-24
Abstract
No abstract record available.
Inventors
- 👤 North John Dudley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 08:28
CPC Classifications
F; F15; F15B; F15B1/00; F15B1/02; F15B1/025; F04; F04B; F04B1/00; F04B1/12; F04B1/20; F04B1/2014; F04B1/2064
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
161 words
A HYDROSTATIC POWER TRANSMISSION INCLUDING A LOW PRESSURE HYDRAULIC ACCUMULATOR CONNECTED TO THE TRANSMISSION PUMP INLET, A LOW PRESSURE BOOST PUMP ARRANGED TO PUMP LIQUID TO THE PUMP INLET, COLLECTING MEANS TO COLLECT LEAKAGE FROM THE PUMP AND TO FEED SUCH LEAKAGE TO THE INLET OF THE BOOST PUMP, AND BY-PASS VALVE CONNECTED BETWEEN THE COLLECTING MEANS AND THE ACCUMULATOR TO MAINTAIN A SUBSTANTIALLY CONSTANT PRESSURE IN SAID COLLECTING MEANS, SAID BY-PASS VALVE COMPRISING A CYLINDER, A PISTON WITHIN THE CYLINDER SPRING-LOADED TO ONE END OF THE THE CYLINDER, VENT MEANS TO CONNECT THE OTHER END OF THE CYLINDER TO ATMOSPHERE, AND A VALVE MEMBER CARRIED BY THE PISTON AND COOPERATING WITH A SEAT LOCATED AT THE SAID ONE END OF THE CYLINDER, WHEREBY THE PRESSURE IN THE COLLECTING MEANS ACTS ON THE PISTON AGAINST THE LOADING OF THE SPRING AND WHEN EXCESSIVE, SEATS THE VALVE TO CLOSE THE BY-PASS AND THUS RAISE THE EFFECTIVE, PUMPING RATE OF THE BOOST PUMP.
Claim 2
Dependent Claim
161 words
A HYDROSTATIC POWER TRANSMISSION INCLUDING A LOW PRESSURE HYDRAULIC ACCUMULATOR CONNECTED TO THE TRANSMISSION PUMP INLET, A LOW PRESSURE BOOST PUMP ARRANGED TO PUMP LIQUID TO THE PUMP INLET, COLLECTING MEANS TO COLLECT LEAKAGE FROM THE PUMP AND TO FEED SUCH LEAKAGE TO THE INLET OF THE BOOST PUMP, AND BY-PASS VALVE CONNECTED BETWEEN THE COLLECTING MEANS AND THE ACCUMULATOR TO MAINTAIN A SUBSTANTIALLY CONSTANT PRESSURE IN SAID COLLECTING MEANS, SAID BY-PASS VALVE COMPRISING A CYLINDER, A PISTON WITHIN THE CYLINDER SPRING-LOADED TO ONE END OF THE THE CYLINDER, VENT MEANS TO CONNECT THE OTHER END OF THE CYLINDER TO ATMOSPHERE, AND A VALVE MEMBER CARRIED BY THE PISTON AND COOPERATING WITH A SEAT LOCATED AT THE SAID ONE END OF THE CYLINDER, WHEREBY THE PRESSURE IN THE COLLECTING MEANS ACTS ON THE PISTON AGAINST THE LOADING OF THE SPRING AND WHEN EXCESSIVE, SEATS THE VALVE TO CLOSE THE BY-PASS AND THUS RAISE THE EFFECTIVE, PUMPING RATE OF THE BOOST PUMP.
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) | 1969-12-12 | 1970-06-13 | 1970-12-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-12-12 | 1974-06-13 | 1974-12-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-12-12 | 1978-06-13 | 1978-12-13 | $7700.00 | Window Closed / Lapsed |