Electrohydraulic directional control valve system

An electrohydraulic directional control valve system comprising, a preliminary directional control valve and a main directional control valve, said main control valve having a first housing provided with an intake port, a return port and at least two load ports;

• a first control spool movable in said first housing from a central neutral position into a respective one of two lateral working positions;
• a pressure chamber arranged at each end of said first spool;
• first spring means arranged in each pressure chamber to urge said first spool into said neutral position;
• control channels connecting, respectively, said pressure chambers to said preliminary control valve, said preliminary control valve having a second housing provided with control chambers;
• a second control spool movable in said second housing from a central neutral position into one of two lateral working positions in which pressure fluid is admitted through one of said control chambers into one of said pressure chambers and the other pressure chamber is released through said return port;
• second spring means arranged at one end of said second spool for urging the same into an additional position in which said control chambers and thus said pressure chambers are interconnected;
• and a proportionally operating solenoid acting on the other end of said second spool to counteract said second spring means.