| 摘要 |
<p>PURPOSE:To make improvements in excavating performance by installing a jack, having an outer end of an outer spoke provided with a cutter bit projected to the outer side from the circumference of a cutter wheel free of expansion or contraction, in the inner part of an inner spoke. CONSTITUTION:When the turnabout of a tunnel excavator is carried out, a jack 9 is operated, expanding or contracting it as much as a specified stroke L, and simultaneously a cutter wheel 1 is rotated or rocked. Then, outbreaking excavation is carried out with a face butting cutter bit 3 set up on a surface 8b of an outer spoke 8.</p> |
