Gear pump 1 delivers fluid to valve 2 and to variable-displacement pump 3 at a pressure maintained by relief valve 4. Upon longitudinal travel of template 5, tracer 6, equipped with a roller and rigidly attached to the spool of valve 2, moves the spool so that fluid is admitted into one of the servomotor cylinders, 7 or 8. Rod 9, shifted to the right or left by the action of the fluid, changes the eccentricity of variable-displacement pump 3 and, consequently, the amount and direction of the fluid delivered to cylinder 10. Piston 11, secured to the vertical slide of the machine tool together with the body of valve 2 and the cutting tool, travels up or down until the spool of valve 2 blocks off a port in the valve body and stops fluid delivery to the servomotor cylinder. Thus, the cutting tool machines a surface on the work corresponding to the profile of template 5. Relief valves 12 protect the system against overloads. Check valves 13 serve to supply fluid to variable-displacement pump 3.
$4212$CHP,Dr$