Steering system for a tunnel boring machine

Claim 1

In a tunnel boring maching: a main frame having a front portion and a rear portion, a head rotatably mounted in said front frame portion adapted to rotate about a central longitudinal axis of said front frame portion, cutting devices mounted on said head for cutting into the face of the tunnel, means for supporting the front frame portion in the tunnel, a vertical joint located rearwardly of the said supporting means and interconnecting the rear end of the front frame portion and the front end of the rear frame portion so as to permit a swinging movement between the two portions only about a vertical axis, a longitudinal slideway on said rear frame portion located rearwardly of said vertical joint, a power actuated anchoring device arranged to be immobilized in the tunnel and provided with pivotably mounted guide means for guiding said slideway, said guide means permitting longitudinal movement of the slideway but restraining the slideway vertically, laterally and torquewise, motor means for displacing said guide means vertically with respect to the anchoring device to provide for the vertical steering of the machine, double acting power jack means connected between the anchoring device and the rear end of the front frame portion for displacing said vertical joint sidewise in the tunnel to thereby turn said slideway and said guide means in the pivotal mounting of the latter to provide for the lateral steering of the machine, and power actuated locking means for locking said vertical joint to interlock said front and rear frame portions in various relative angular positions To thereby permit said double acting jack means to advance the main frame with respect to said anchoring device.