Pump 1 delivers fluid to the left end of cylinder 2 and to the body of valve 3. Piston 4 and template 5, which is rigidly attached to the piston rod, are moved to the right by the fluid. Fluid from the right end of cylinder 2 is discharged through check valve 7 to the tank. Relief valve 8 maintains a definite pressure in the system. Upon travel of template 5, tracer 9, equipped with a roller and rigidly attached to the spool of valve 3, raises the spool. At this, fluid from pump 1 is delivered to the upper end of cylinder 6 which is mounted, together with the body of valve 3 and milling cutter 11, on the vertical slide of the milling machine. The rod of piston 10 is attached to the column. The fluid raises cylinder 6 until the spool of valve 3 blocks off ports in the valve body, stopping fluid delivery to cylinder 6. Fluid from the exhaust end of the cylinder is discharged through valve 3 to the tank. When tracer 9 moves downward, cylinder 6 also moves downward together with the milling cutter. Thus, milling cutter 11 reproduces a contour on the work which corresponds to the profile of template 5.
$4213$CHP,Dr$