Rectangular tunnel boring machine and method

A method of cutting a tunnel having a generally rectangular cross-sectional configuration in a plane perpendicular to the longitudinal axis of the tunnel by removal of material from the tunnel end face with a rotatable cutting wheel having a generally cylindrical lateral cutting wheel surface with a central axis coaxial with the axis of rotation and having an upper symmetrical generally convex cutting surface with a central axis coaxial with the axis of rotation comprising the steps of tilting the cutting wheel axis of rotation in a forward direction relative a plane perpendicular to the tunnel longitudinal axis at an angle of inclination between 5.degree. and 30.degree.;

• advancing the cutting wheel against the tunnel face in a direction substantially parallel to the tunnel longitudinal axis and cutting a first tunnel face portion having a shape defined by the shape of a forward portion of the lateral cutting surface and simultaneously cutting a second tunnel face portion having a shape defined by a forward portion of the upper cutting surface of said first tunnel face portion and intersecting said second tunnel face portion at an angle substantially equal to said angle of inclination of the rotational axis plus 90.degree. whereby the forward projection of said first tunnel face portion and said second tunnel face portion in a direction parallel the tunnel central longitudinal axis defines a three-dimensional figure having a substantially rectangular cross-sectional configuration with rounded corner portions;
• collecting rock cuttings at a lower, leading-edge portion of the cutting wheel and sweeping the rock cuttings peripherally rearwardly with paddle devices mounted on the cutting wheel for subsequent collection and removal from a position rearward of the cutting wheel axis of rotation and below the cutting wheel trailing edge.

A machine for boring a tunnel having an end face wall, a roof wall, a bottom wall, and opposite side walls which comprises:

• a rotatable cutting wheel means having an annular peripheral wall supporting a plurality of cutting devices and a generally convex shaped upper wall supporting a plurality of cutting devices and being rotatable about an axis of rotation which is inclined in a forward direction relative to a plane perpendicular to the longitudinal axis of the tunnel for simultaneously cutting the tunnel face along two intersecting surfaces defined by said cutting devices on said annular peripheral wall and said cutting devices on said convex-shape upper wall;
• cutting wheel support means centrally mounted in said cutting wheel means for rotatably supporting said cutting wheel means;
• support shoe means mounted beneath said cutting wheel support means for movably supporting said cutting wheel means on the tunnel floor;
• drive motor means operatively associated with said cutting wheel means for causing rotation of said cutting wheel means relative to the tunnel face and said cutting wheel support means;
• thrust means connected in thrust transmitting relationship with said cutting wheel support means for advancing said cutting wheel and said support shoe means toward the tunnel face;
• and
• gripping means associated with said thrust means for gripping engagement with the opposite tunnel side walls to prevent axial rearward movement as said cutting wheel means and cutting wheel support means and said support shoe means are advanced toward the tunnel face.