Directional control valve with flow path through valve spool

A directional control air valve having a valve body mounted on a base member a valve spool bore formed in the valve body in which a valve spool is movably mounted, the base member being provided with a pressurized air supply inlet port, an exhaust port, a first cylinder port and a second cylinder port, characterized in that:

• (a) a first pressurized air supply chamber is formed in the wall of said valve spool bore, and a second pressurized air supply chamber is formed in the wall of said valve spool bore in a position longitudinally spaced apart from the first pressurized air supply port;
• (b) said valve spool has a longitudinally disposed pressurized air flow chamber formed therein which is connected to said first and second pressurized air supply chambers, and to said pressurized air supply inlet port;
• (c) an exhaust chamber is formed in the wall of said valve spool bore in an intermediate position between said first and second pressurized air supply chambers for connection to said exhaust port;
• (d) a first cylinder chamber is formed in the wall of said valve spool bore in an intermediate position between said first pressurized air supply chamber and said exhaust chamber;
• (e) a second cylinder chamber is formed in the wall of said valve spool bore in an intermediate position between said second pressurized air supply chamber and said exhaust chamber;
• (f) said valve spool includes annular seal means at the ends thereof to seal said first and second pressurized air supply chambers from the end portions of the valve spool bore;
• (g) a plurality of annular valve seal members are mounted around the periphery of the valve spool between the annular seal means, and in longitudinal position spaced apart from each other and from the annular seal means, for controlling the flow of pressurized supply air between the first and second pressurized air supply chambers and the first and second cylinder chambers, and the flow of exhaust air between the first and second cylinder chambers and the exhaust chamber;
• and,
• (h) said valve includes means for moving the valve spool to a first position to connect said first pressurized air supply chamber with said first cylinder chamber and said exhaust chamber to said second cylinder chamber, and to a second position to connect the second pressurized air supply chamber with the second cylinder chamber and said exhaust chamber to said first cylinder chamber.