Hydraulic implement control system - has spring-loaded valve plug parallel to changeover valve controlling return connection

摘要

The control system is for a hydraulic implement, partic. one mounted on an agricultural vehicle, having a changeover valve, a barrier block and a pilot stage controlling the latter. The valve has a spring-loaded changeover slide subjected to the pressure in a control chamber, directing the incoming fluid down a return pipe or a passage via a non-return valve in the barrier block to a ram. The plug (48) of a pressure valve (49) controls, dependent on the pressure in the supply pipe (31), a second connection (35,24,51,52,47.23) from the latter to the return pipe (34), parallel to that (22,39,23) controlled by the changeover slide (17). The side of this plug (57) against which a spring (61) acts is connected to the control chamber (19).