Abstract: A tunneling machine adapted to cut tunnels on a continuous basis and to apply continuous pressure on the tunnel face even during repositioning of the gripping legs is disclosed. The machine includes at least two supporting frames having a plurality of extendible feet which are adapted to grip the tunnel wall. The support frames are provided with axial bores therethrough, and a hollow piston extends through all of the bores for longitudinal movement along the axis of the tunnel. In accordance with the method, a tunneling operation is carried out by extending at least one pair of extendible feet against the walls of the tunnel to securely hold at least one of the support frames relative to the tunnel wall. The piston chamber of each support frame which is clamped to the wall is pressurized to drive the cutter head against the face of the tunnel.

Abstract: There is disclosed a hard rock trench cutting machine comprising a main body assembly and a cutting wheel assembly. A cylinder is transversely mounted on the main body assembly and carries a pair of pistons which extend axially from each end of the cylinder. Pads are provided on each piston to bear against the sidewalls of a trench. Each piston has an end face within the cylinder which, together with an inner sidewall of the cylinder, comprises a pressure chamber adapted to force the pads against the trench. The main body and its cylinder are free to move laterally relative to the pistons when the cylinder is pressurized. Extensible arms are provided between the pistons and the main body assembly for forcing the main body assembly and its cutting wheel forwardly to progressively cut a trench. A steering assembly is provided to shift the main body assembly laterally relative to the pistons and about the central axis of the cutting wheel.

Abstract: A diametrically compact tunneling machine for boring tunnels is disclosed. The machine includes a tubular support frame having a hollow piston mounted therein which is movable from a retracted position in the support frame to an extended position. A drive shaft is rotatably mounted in the hollow piston and carries a cutter head at one end. The hollow piston is restrained against rotational movement relative to the support frame and the drive shaft is constrained against longitudinal movement relative to the hollow piston. A plurality of radially extendible feet project from the support frame to the tunnel wall to grip the tunnel wall during a tunneling operation wherein the hollow piston is driven forwardly so that the cutter head works on the tunnel face.

Abstract: A hard rock trench cutting machine includes a main body assembly, a cutter wheel assembly, and a longitudinal thrust assembly. The main body assembly includes two longitudinally extending cantilever support booms each having a forward portion and a rearward portion. The rearward portions of the support booms are connected to four side wall support feet which move laterally relative to the support booms between a retracted position and an extended position. The cutter wheel assembly includes a cutter wheel frame slidably disposed on the forward portion of the support booms. A cutter wheel drum carrying a plurality of roller cutters is rotatably carried by the cutter wheel frame for rotation about an axis. The longitudinal thrust assembly extends between the main body assembly and the cutter wheel assembly for pushing the roller cutters against the trench end face.