Upon horizontal travel of template 1, stylus 2, through steel ball 3, actuates valve spool 4. When the stylus is moved upward by the contour of the template, spool 4 moves upward and fluid, delivered by the pump to the valve, is admitted into the upper end of cylinder 6. Piston rod 5 is fixed and cylinder 6 is attached to the vertical slide of the spindle head. From the lower end of cylinder 6 fluid is discharged through the valve to the tank. At this, the spindle head travels upward. When the stylus moves downward, spool 4 descends below its middle position and fluid from the pump is admitted into the lower end of cylinder 6. At this, the spindle head travels downward. Fluid from the upper end of cylinder 6 is discharged through the valve to the tank.
$4209$CHP,Dr$