| 摘要 |
<p>A tunnel boring including a rotatable head is disclosed. The head has a cutting face transverse to a head axis of rotation. A plurality of cutters are mounted in the face each on an associated one of a plurality of hubs. The hubs mounted for rotation about a respective hub axes. Each such respective hub axis is in an imaginary plane intersecting another imaginary plane including the head axis. Each of the cutters has a cutting edge symmetrical about another imaginary plane which is skewed with respect to the respective hub axis of the associated hub.</p> |
