| 摘要 |
<p>Tunnel driving apparatus employs a hollow support tube positioned axially centrally inside a drive shield. An inner cutting machine is supported and positioned inside the support tube and serves to cut away a central region of a working face. Outer cutting machines are also supported by the support tube but on the exterior thereof. The outer cutting machines serve to cut away the outer region of the working face. The cutting machines may each have a pivotable arm carrying cutting drums and are supported and guided for axial and rotary motion relative to the support tube.</p> |
