SHIELD MACHINE OF DEFORMED CROSS SECTION

摘要

PROBLEM TO BE SOLVED: To provide a shield machine of deformed cross section which is structurally simple and which is provided with rotating corner cutters of high durability. SOLUTION: Spokes 4 extending radially from the center of a main cutter 3 are each provided with a telescopic arm 11, and a rotary corner cutter 5 is provided on each telescopic arm 11. The telescopic arm 11 is telescoped by a hydraulic jack 12 provided in each spoke 4, and the corner cutter 5 is rotated by a hydraulic motor 13 provided in each telescopic arm 11.