| 摘要 |
A raise boring machine for producing a raise of circular cross section has a main frame with a rotating drum which has two rotating tangentially cutting heads. Three wall engaging shoes are suspended in rods in toggle arrangements and they are biased outwardly against the wall of the raise by means of spring devices braced between the shoes. By this arrangement these shoes guide the machine by sliding on the wall during a cutting advance of the main frame effected by means of six advance jacks connected between the main frame and a rear anchoring frame. During the time that the anchoring frame is released from the raise and pulled forward by the advance jacks, however, the same shoes hold the main frame firmly in the raise as a result of the action of the toggle joints. Steering is effected by moving the rear portion of the main frame sidewise in the anchoring frame in any desired direction. |
