| 摘要 |
The machine frame is mounted onto a lower portion of an expandable forward support ring for sideways pivotal movement of the frame and the cutterhead carried thereby about an axis which is generally parallel to the centerline of the tunnel. The cutterhead cuts a circle which is generally equal in diameter with the support ring. A steering link extends laterally of the tunnel and is connected at one of its ends to the frame and at its opposite end to the support ring. It is used for tilting the cutterhead sideways, so as to offset the cutterhead from the support ring, to in that manner change the course of the tunnel. |
