| 摘要 |
PURPOSE:To excavate the ground easily in the shape of an elliptical section by inclining the center of rotation so as to turn in the direction of the center of a shield main body to provide a plurality of cutter heads to the front of the shield main body in a rotatable manner. CONSTITUTION:The centers of rotary shafts of two units of cutter heads 3 are inclined to arrange so as to turn in the direction of the center of a shield main body 1 and, at the same time, the peripheral surfaces of the cutter heads 3 are respectively shifted in front and rear to install so that they are not made to interfere with each other. The main body 1 is driven into the ground by a shield jack 2 while rotating the cutter heads 3 at a time with cutter head motors 6. In addition, after earth excavated by cutters 4 is taken into a chamber 1b, the earth is moved from the chamber 1b with an earth-mover 7. |
