| 摘要 |
PURPOSE:To simplify the shift of a curve and a straight line by providing a plurality of curved mechanism bent by a articulate hydraulic jack to the front side of a slide type tail shield, and forming a super-steep curve shield excavator. CONSTITUTION:In the case of curve execution, a piston lever 2a of an articulate jack 2 outward of the curve is extended, the front shield 1a is bent against the middle shield 1b, a piston lever 3a of a tail shield jack 3 inward of the curve is contracted, and the tail shield 1c is slide forward to shorten the length of a machine, so that the rear end of the tail shield 1c and the tail shield 6 do not interfere in a short segment 71. When excavation is shifted to straight execution, the piston lever 2a is contracted to restore a bending angle, and when excavation is made by the shield jacks, the front shield 1a and middle shield 1b are slid forward and are restored to the straight execution. |
