Abstract: The front end portion of an endless belt type conveyor is detachably connected to the floor of a self-propelled tunneling shield, and the rear end of the conveyor is supported inclined upwardly by a trailing, mobile power unit which rides on spaced apart rails disposed along the tunnel floor. A pair of double acting hydraulic cylinders advance and retract a boom supporting carriage along support rails mounted along the length of the conveyor. An elongate boom is mounted on the carriage for movement with the carriage toward and away from the tunnel face. A combination digging and hoeing excavator tool is carried by the front end portion of the boom to loosen material at the tunnel face and then hoe the loosened material rearwardly onto the conveyor.

Abstract: Large hole boring equipment is used for boring a large diameter blind pilot hole. Then such equipment is removed from the hole and a room is blasted at the closed or blind end of the hole. Then the large hole cutterhead is replaced by a reamer and the equipment is inserted back into the hole. The reamer is an adjustable diameter type and its diameter is increased once it is within such room. A wrench carried by a drive head of a drilling machine is used to rotate a small diameter shaft which extends downwardly through the drill string to a lead screw which is a part of the reamer. Rotation of the lead screw causes axial travel of a lead nut. As the lead nut travels it moves a plurality of links which in turn swing a plurality of cutter carrying arms outwardly from the axis of rotation.

Abstract: A main frame includes an annular beam by which the cutterhead is mounted onto an earth boring machine for a rotation about an axis of rotation. A plurality of radial spoke beams extend generally vertically at the front of cutterhead and curve rearwardly to intersect with the annular beam. Each radial spoke beam is constructed from a pair of spaced apart side plate members which define spaces between them for receiving a plurality of roller cutter mounts therebetween. Roller cutters, including gauge cutters, can be installed and removed from their associated cutter mounts from the rear side of the cutterhead. A plurality of generally radially elongate cut-ground-material passageways extend through the cutterhead in the regions between the radial spoke beams.

Abstract: Roller cutters are mounted onto a cutterhead from the rear side of the cutterhead. A load transfer block is insertable between a stator portion of each cutter and a generally forwardly directed load-carrying surface on the cutter-head frame. Loads imposed on the roller cutter during boring are transmitted rearwardly from the stator to the load transfer block, and from the load transfer block to the cutterhead frame.

Abstract: The main frame of the cutterhead comprises a plurality of radial spoke beams which are interconnected between a box-like hub structure and an annular box beam by which the cutterhead is mounted for rotation. Cutter mounting wells are defined by and between side wall portions of the radial spoke beams. The mined material passes rearwardly through the cutterhead via openings between adjacent radial spoke beams and open spaces in the cutter mounting wells. Cutter mounts span laterally between the side plate members and laterally brace the radial spoke beams in addition to mounting the cutters. The radial spoke beams curve rearwardly at their outer ends and connect to the annular box beam at a location spaced enough rearwardly from the front portions of the spoke beams that a room is defined within the cutterhead. Roller type cutters are installed onto and removed from the cutterhead frame from the rear side of the cutterhead.

Abstract: A machine for mechanical tunnel boring, of the rotating cutter head type, comprising a grid rigid with the cutter head, parallel to the theoretical boring surface, provided with a set of void spaces wherefrom the cutting tools slightly project, said void spaces having a size corresponding to the optimum dimensions of the fragment of mined material.

Abstract: An earth digging tool is mounted on the head of a tripod, the legs of which are double-acting hydraulic cylinders. The rear ends of the cylinders are connected to a rotor which is supported in a tunneling shield for rotation about an axis extending longitudinally of the tunnel. The cylinders are selectively extended and retracted for the purpose of moving the cutting tool forwardly and rearwardly and also up and down and sideways. The entire excavator is rotated for changing the sideways attitude of the digging tool. Universal joints are provided at both ends of each hydraulic cylinder, for substantially isolating them from bending moments and torque. A telescopic torque tube assembly is interconnected between the cutting tool mounting head and a gimbal carried by the rotor. The torque tube carries the bending moments and torque loads and transmits them back to the rotor.

Abstract: A boring assembly is advanced upwardly by thrust rams acting on a column guided traveling cross frame connected to the power tunneler from below by a non-rotating sectional support column. The support column is anchored to a holding table situated underground above the thrust ram while sections are being added to or removed from it. The boring assembly is driven by either a hydraulic motor housed in the cross frame, via a sectional drill stem housed within the support column, or by a hydraulic motor housed directly within the boring assembly.

Abstract: A bedplate is rigidly affixed relative to the tunnel floor and includes a centrally disposed shaft extending upwardly therefrom. A rotatable base member is mounted on the bedplate for rotation about the central shaft. A boring machine adapted to bore upwardly is secured to the rotatable base member. The boring machine is swung upwardly along a selected arc of vertical circle and the base member is rotated to a selected azimuth. Following rotation, the rotatable base member is itself rigidly affixed relative to the tunnel floor.

Abstract: Front and rear shields are telescopically joined together. The front shield carries a power driven rotary cutterhead means. Main thrust rams are provided between the two shields for pushing the forward shield forwardly relative to the rear shield while the cutterhead means is being operated to mine the tunnel face, and also to pull the rear shield forwardly relative to the front shield. The rear shield includes a gripper assembly for reacting thrust and torque and a plurality of groups of auxiliary thrust rams which extend rearwardly from the rear shield to contact forward end portions of a tunnel lining which is erected under cover of a tail section of the rear shield. The auxiliary thrust rams are extendable a distance that is at least slightly larger than the axial length of one ring of tunnel lining segments. The main thrust rams are extendable a distance that is slightly larger than 1x of the stroke of the auxiliary thrust rams, where x is the number of groups of auxiliary thrust rams.

Abstract: A cutter wheel is mounted at the lower end of the machine for rotation about a horizontal tubular support. Cuttings are picked up by buckets on the cutter wheel and are directed into the tubular support to be received by an endless bucket conveyor which carries them upwardly to a discharge station. As the machine is advanced the cutter wheel is rotated to make a first cut in the shape of the leading portion of the cutter wheel. The cutter wheel is then retracted out from the cut and is rotated about the axis of the hole. This repositions the cutter wheel so that when it is advanced again it will make a second cut which crosses the first. This procedure is repeated until the desired cross-sectional configuration (e.g. circular) of the hole is obtained.

Abstract: A cutting tool is mounted on the head of a support tripod, the legs of which are double-acting hydraulic cylinders. The rear ends of said cylinders are either pivotally connected to a frame portion of a tunneling machine or to movable barrel portions of three base cylinders having fixed rod portions. The cylinders are selectively extended and retracted for the purpose of moving the cutting tool forwardly and rearwardly and also up and down and sideways.