| 摘要 |
PROBLEM TO BE SOLVED: To obtain a shield machine, in which a cutter bit can be exchanged at a place in the intermediate section of jacking between shafts. SOLUTION: A cutter shaft 7 is penetrated rotatably at the center of the partition wall 6 of a shield cylinder 1. Radial each cutter spoke installed on the outer circumference of the cutter shaft 7 is constituted as expansion type cutter-spoke mechanisms 9 varying length in the radial direction of the cutter spokes from a longest state to a shortest state. In each expansion type cutter- spoke mechanism 9, a plurality of detachable type cutter bits 10 are projected from fronts while a jacking posture in the direction orthogonal to the cutter shaft 7 under the longest state is taken, and the base-section ends of the cutter bits are connected to the cutter shaft 7 in a derrickable manner respectively so as to take the exchanging posture of the cutter bits made to fall to the partition wall 6 side under the shortest state. A bit exchanging operation chamber 11, in which a rotary cutter 8 is housed, is installed around the cutter shaft 7 while using the partition wall 6 as a supporter. A gate 14 closing the front inlet of the bit exchanging operation chamber 1 is housed in the chamber 11. |
