Pump 1 delivers fluid through starting valve 2, directional valve 3, controlled by reversing pilot rotary valve 4, and passage a of the stationary piston rod to the left end of cylinder 5, moving the cylinder to the left. In this case, the right end of valve 3 is connected to the delivery line. Fluid from the right end of cylinder 5 is discharged through passage d of the stationary piston rod, valve 3, pressure reducing valve 9 and flow-control valve 10 to the tank. Fluid is admitted through side ports, radial and axial passages to the upper end of valve 9 and acts on plunger 7 which is subject underneath to the action of spring 6. The higher the pressure in the upper end of valve 9, the less the amount of fluid delivered to valve 10, so that a low pressure is constantly maintained with little variation at the input to flow-control valve 10. Relief valve 8 protects the system against overloads. As cylinder 5 travels to the left, trip dog b, mounted on the table, turns the lever of reversing valve 4. This connects the left end of valve 3 to the delivery line, and the right end to the tank, shifting the spool of valve 3 to the right. Then fluid from the pump is delivered to the right end of cylinder 5, moving it to the right. The drive provides for equal speeds of travel of the cylinder and table in both directions.
$4195$CHP,Dr$