SHIELD MACHINE

PURPOSE:To drill holes in an obstacle by a shield machine itself for its removal by setting the top end of a slide hood movably in longitudinal direction, oscillating the slide hood in circumferential direction of a cutter head, and cutting and eliminating as it is clamped. CONSTITUTION:A cutter head 1 is attached at the top end of a device main body A. Also a slide hood 2 to the top of which a cutter bit 2a is attached is installed on the upper periphery surface of the device main body A including the cutter head 1. The slide hood 2 is forced out forward by a slide jack 3. A hood longitudinal slide hole 4 and a hood oscillation hole 5 are drilled in the device main body A according to the movement of the slide jack 3. Then, when the cutter head 1 is rotated in forward direction, soil is dug, and encountered with an obstacle, a fixed bit 11 is bitten into an object to be cut and broken. Under this condition, a rotation detector for the cutter head 1 detects a variation in rotating torque, and stops the rotation of the cutter head 1. Lastly a movable bit 10 opposed to the fixed bit 11 bitten into the object to be broken is driven to cut or break the object to be cut and broken.