| 摘要 |
<p>An apparatus (20) for forming an underground tunnel for the reception of cable, conduits and the like comprises a semi-rigid advancing conduit (46), and advancing and retracting mechanism (51) for moving the advancing conduit and a take-up reel (36) for receiving the advancing conduit. A hydraulic drill motor (78) is mounted to the leading end (76) of the advancing conduit by means of a coupling member (77). A bent housing (79) is mounted at a small angle relative to the drill motor for rotatably supporting a drill bit (81). The coupling (77) allows the orientation of the drill bit (81) to be changed relative to a longitudinal axis of the advancing conduit (46), allowing the apparatus to be steered effectively.</p> |
