Patent ID: 8328293
Filing Date: 2012-12-11
Classification: E21D

Abstract:
1. A shield machine comprising: a shield machine main body including a body; a plurality of shield jacks configured to cause the shield machine main body to move ahead; and an excavator configured on a front end side of the shield machine main body to excavate natural ground, the shield machine further comprising: a first rotating member supported at a front end side portion of the shield machine main body to be rotatable around a first center axis parallel to a central axis of the shield machine main body; a first rotating device configured to cause the first rotating member to rotate; a swinging member supported by the first rotating member so as to be swingable around a second center axis parallel to the first center axis and spaced apart from the first center axis; a swinging device configured to cause the swinging member to swing with respect to the first rotating member independently from the first rotating device; a rotary cutter head supported by the swinging member so as to be rotatable around a third center axis parallel to the second center axis and spaced apart from the second center axis, and including a plurality of cutters on an excavating surface thereof; a third rotating device including an actuator configured to cause the rotary cutter head to rotate with respect to the swinging member independently from the first rotating device and the swinging device, the actuator being a hydraulic motor or electric motor provided in the swinging member; and a controller configured to control the first rotating device, the swinging device, and the third rotating device, wherein the rotary cutter head is configured to be able to excavate the natural ground located in front of a vicinity of the central axis of the shield machine main body while swinging in a direction intersecting with the central axis of the shield machine main body.