| 摘要 |
PURPOSE:To relieve the impact pressure acting on a cutting tool which cuts an inside surface bead and to extend the life of the cutting tool by disposing a roller on the rear top surface of the cutting tool, and providing the shaft of the roller along the bearing groove inclined backward in a way that the shaft can be slided elastically by means of a spring. CONSTITUTION:A roller 18 is provided behind a cutting tool 11 which cuts the inside surface bead of an electric welded pipe. Said roller is made slidable integrally with a shaft 20 together with a bearing 22 pressed by, for example, a spring 25, in an inclined groove 23. The spring 25 which supports the roller 18 is then contracted to relieve the force acting on the tool 11 when the tool 11 is shifted to a deep part or to the right or left from the normal cutting position by impact force during cutting of the bead. When the pipe moves in an opposite direction 24 on account of a springback, the rollers 18 climbs the slope and the cutter body is depressed by as much as a space 19, by which the tool 11 is detached from the inside surface of the pipe. The failure of the cutting tool owing to the impact force generated in the stage of cutting the inside surface bead is thus prevented. |
