Stylus 1, mounted on a bracket of the cross slide, is held by spring 2 in contact with the profile of template 3 and travels along the template upon longitudinal travel of the saddle. As it turns back and forth, stylus 1 varies the flow of air from nozzle 4 to which air is delivered under pressure. The variations in air pressure actuate bellows 5 and 6, counterbalanced by springs 7 and 8, which shift valve spools 9 and 10. Valve spool 9 controls the operation of cross feed cylinder 11 by admitting hydraulic fluid into it. The fluid is delivered to the valve by a pump. Cylinder 11 is secured to the lathe bed and the rod of its piston 13 is linked to the cross slide. Valve spool 10 controls the longitudinal feed of the slide by releasing fluid from cylinder 12 to which it is delivered under pressure. Piston rod 14 is linked to the bed, and the cylinder travels together with the saddle. Thus, the single-point tool reproduces a contour on work 15 which corresponds to the profile of template 3.
$4210$CHP,Dr$