CUTTING METHOD

PURPOSE:To prevent a cutting tool from damage, by adjusting a feed distance of cutting in each section to a fixed dimension in the case of a cutting method in which the whole cutting is finished by cutting a work dividing the whole process of cutting into several stages. CONSTITUTION:Adjusting a feed distance of sectional cutting for a cutting feed stroke rod 30 and a limit switch 31 and touching the point end of a cutting tool to a work, if a moving dog 18 is adapted to a stopper 23, an engagement part 27 of a cutting feed switching lever 28 is unlatched, simultaneously a limit switch LS34 operates resulting in the cutting feed operated by hydraulic power. Then if the end of the stroke rod 30 is adaptd to an actuating piece 32 of the switch LS31, the cutting feed is stopped, and a working rod 17 is moved returning. At this time of returning motion, if the dog 18 is adapted to an actuating piece 35 of the switch LS34, said engagement part 27 is engaged with a frame unit 16 finishing the first sectional cutting, and next, the feed is switched to a quick feed by pneumatic power resulting in the extracting actuation of a drill.