| 摘要 |
PROBLEM TO BE SOLVED: To provide a preparative cutter device for a shield machine, which can positively perform a locking function without requiring highly accurate working of the cutter device. SOLUTION: According to the preparative cutter device, a cutter head 3 has an opening 10 formed in a front surface, and guide walls 13, 14 are extended inward from the opening 10. A mobile member 16 having an auxiliary cutter bit 9 at its front end is protrudably arranged along the guide walls 13, 14. Then, a rotatable plate 31 is rotatably interposed between the guide walls 13, 14, and the rotatable plate 31 has a through hole 31c into which the mobile member 16 is slidably inserted. When the mobile member 16 is protruded to release penetration of the mobile member 16 into the rotatble plate 31, a spring member 41 rotates the rotatable plate 31 through predetermined degrees until a stopper member 34 abuts on the rotatable plate 31, whereby the rotatable plate 31 can restrain the mobile member 16 from withdrawing. |
