CONTROL VALVE FOR TRACTOR-IMPLEMENT HYDRAULIC SYSTEM

摘要

A tractor-implement hydraulic system having a valve interposed between a cylinder-piston assembly, a reservoir and a variable displacement pressure and flow compensated pump having compensating means is disclosed herein. The valve has a housing which has a bore supporting a valve spool and an inlet chamber and pressure chamber in communication with the valve bore with the inlet chamber being connected to the pump while the pressure chamber is connected to both the cylinder and the compensating means so that the cylinder and compensating means are immediately interconnected when the valve spool is actuated in one direction. The valve housing also has a return passage between the cylinder and the reservoir with a valve therein that normally blocks flow and is opened in response to movement of the valve spool in an opposite direction.