Proportional control valve with preconditioned inlet modulating relief valve
US3995532A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 15, 1974 |
| Grant date | Dec 7, 1976 |
| Priority date | — |
| Expiry date | Jul 15, 1994 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/87185
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A fluid control circuit for regulating flow from a source of fluid under pressure to a hydraulic motor, including a control valve having a movable spool for communicating fluid entering an inlet chamber from the source with service chambers in communication with the motor, an inlet relief valve selectively pressurizing the inlet chamber in response to spring means and signal fluid received from the service chambers through signal passages. The control valve and its spool are configured to insure that the signal passages are always in positive communication either with one of the service chambers or a drain in order to facilitate manipulation of the spool. The control valve is also adapted to communicate signal fluid to the relief valve prior to communication of either service chamber with the inlet chamber in order to precondition the relief valve and improve response of the motor to manipulation of the control valve.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.