SHIELD EXCAVATOR TO BE CONNECTED UNDER GROUND

摘要

PURPOSE:To prevent the degradation of facing by a method in which a ring part is set in the inside of the hood of an excavator having an expandible bit on the peripheral side of its cutter, and when excavation is made until immediately before the other excavator, the bit is retracted into the peripheral side and the ring part is pushed out. CONSTITUTION:A ring part 28 to be slid in the axial direction by a jack 35 is set in the hood 3 of a shield excavator 1 having an expandible bit 10 on the peripheral side of its cutter wheel 4. In the shield excavator 1' stopped, the wheel 4' is housed in the hood 3'. By the excavator 1, further excavation is made by extending the bit 10 maximumly until immediately before the excavator 1'. After the excavation is ended, the bit 10 is retracted and the ring part 28 is pushed out to prevent the degradation of facing by closing the aperture. Both the excavators 1 and 1' are connected to take apart the inside. The connecting operation can thus be effectively made.