| 摘要 |
PURPOSE:To change each bit in a simple manner by rotatably providing a spherical working room at the tip end section of the cylindrical body of an excavator main body, projecting an excavating device and each cutter toward the inside and the outside of the working room respectively, and thereby directing each cutter section toward the inside of the cylindrical body when the working room is rotated. CONSTITUTION:A plurality of propulsive jacks 11 is disposed on the inner circumference of a circular cylindrical body 1, a spherical working room 2 is rotatably housed in the tip end of the cylindrical body so as to be set, and a seal is provided between the working room 2 and the cylindrical body 1, so that an excavator 3 is thereby housed in the working room 2 in a hollow ball shape. In this case, the excavator 3 is housed in the working room 2 where an entrance 21 is opened, and a cutter 31 in the front surface of which each bit 33 is fixed, is exposed out of the tip end of the cylindrical body 1. Each over-cutter 32 is drawn in, so that the cutter 31 is thereby housed in the working room 2. Each bit 33 of the cutter 31 is inspected so as to be clanged within the cylindrical body 1 with the entrance 21 closed with a curved door. By this constitution, excavation in a long distance can thereby by performed. |
