| 摘要 |
<p>A cutting tool is mounted on the head of a support tripod, the legs of which are double-acting hydraulic cylinders. The rear ends of said cylinders are either pivotally connected to a frame portion of a tunneling machine or to movable barrel portions of three base cylinders having fixed rod portions. The cylinders are selectively extended and retracted for the purpose of moving the cutting tool forwardly and rearwardly and also up and down and sideways.</p> |
