Hydraulic circuit having dual electrohydraulic control valves
US5568759A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 7, 1995 |
| Grant date | Oct 29, 1996 |
| Priority date | — |
| Expiry date | Jun 7, 2015 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF15B21/087
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A three position four way directional control valve having a single spool is typically used for controlling fluid flow from a pump to a cylinder and from the motor to a tank. The present invention includes a pair of electrohydraulic control valves with one of the control valves controlling pump-to-cylinder communication between a pump and the rod end and head end chambers of a hydraulic cylinder while the other control valve controls cylinder-to-tank communication between the rod end and head end chambers and the tank. Each of the control valves includes a displacement controlled proportional valve for controlling the position of a pilot operated valve member. Actuation of the hydraulic cylinder requires moving the valve member of one control valve to control pump-to-cylinder communication to one of the chambers while simultaneously moving the valve member of the other control valve for establishing cylinder-to-tank communication between the other chamber and the tank.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.