Lever 1 carries knife 2 and feeler 3. Potato 4 turns about fixed axis A and travels longitudinally along this axis (perpendicular to the plane of the drawing) by a mechanism that is not shown. The knife is automatically set to the required depth by feeler 3 which contacts the surface of the potato. The knife and its holder are held to the potato by the force of spring 5.
$530$SL,FD$