Pressure-compensated flow control valve
Abstract
Abstract A CONTROL VALVE ASSEMBLY FOR CONTROLLING A TWO-WAY HYDRAULIC CYLINDER INCLUDING A PRESSURE-COMPENSATED FLOW CONTROL VALVE FOR MAINTAINING A CONSTANT PREDETERMINED FLOW RATE TO THE HYDRAULIC CYLINDER, A PAIR OF CHECK VALVES FOR PREVENTING THE RETURN OF FLUID FROM THE ENDS OF THE HYDRAULIC CYLINDER, A PAIR OF OPPOSED HYDRAULICALLY-OPERATED PISTONS RESPONSIVE TO FLUID PRESSURE BETWEEN THEIR FACES FOR RESPECTIVELY ENGAGING AND UNSEATING THE CHECK VALVES AND A MANUALLY-OPERATED SPOOL-TYPE DIRECTION CONTROL VALVE FOR SELECTIVELY CONNECTING THE OUTLETS OF THE PRESSURE-COMPENSATED VALVE TO ONE OR THE OTHER OF THE ENDS OF THE HYDRAULIC CYLINDER AND TO THE FACES OF THE OPPOSED PISTONS.
Inventors
- 👤 Donald James Parquet
- 👤 Daniel Luce Hall
Bibliographic Details
Claims Analysis
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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 |