Upon uniform horizontal travel of slide 1, former bar a, mounted on the slide, actuates the end of lever 2. Lever 2 turns about fixed axis A and is linked to valve 3. Pump 4 delivers fluid to power cylinder 5. When valve member 3 is raised, pressure in cylinder 5 drops and piston 6 moves downward with slide 1. When valve member 3 is lowered, slide 1 moves upward. Thus, piston 6 follows up the motion of valve member 3 and the cutting tool describes a curve which is similar to, but a mirror image of, the profile of the former bar.
$3951$LHP,Dr$