Abstract: A rock drilling appartatus wherein the rock drill is a cluster of independent rock drills arranged in a circular pattern about a central axis for rotation. The cluster drill is drawn into a hole to be drilled by a drill string in a previously drilled smaller diameter hole. The drill string provides pressure fluid to operate the cluster drill and rotation as well as the tractive force to draw the cluster drill into the hole to form a large diameter straight drilled hole. Pressure fluid and rock cuttings exit the larger diameter hole and discharge of rock particles is further aided by use of a trailing auger rotated by the cluster drill. A particular application of this device is in the production of horizontal bored holes of moderate diameter under, for example, roadways, foundations, and the like. The drill string acting as a centering device produces a straight hole in difficult rock formations.

Abstract: A method for excavating a hole and an apparatus therefore are suitable for the operation of excavating a hole used for laying a lateral sewer or mounting pipe, which extends from a main sewer pipe toward the ground surface, on the main sewer pipe. The method comprises the step of rotating a rod about its axis in a space provided in the ground while advancing the rod in the direction of penetrating a wall member defining the space, and the step of utilizing the advanced rod as a guide while excavating a hole in the ground from the tip end of the rod toward the space. The apparatus embodying the method described above comprises a rod propelling machine disposed in a space provided in the ground for rotating a rod about its axis while advancing the rod and a excavating machine utilizing the advanced rod as a guide while excavating a hole in the ground from the tip end of the rod toward the space.

Abstract: An improved raise boring bit to enhance cuttings removal and prevent accumulation of cuttings on the body of the bit, which utilizes a pair of radial rails and a plate connected with and strengthening the rails while defining an opening for the flow of cuttings beside the stem and the radial rails during boring. Cutter mounting means are disposed at intervals along the radial rails to permit the flow of cuttings between the rails and the mounting means. At least one wing extends radially from the plate for supporting additional cutters, a vertical stabilizer roller is mounted on the end of the wing and struts extend between adjacent sides of the wings for stability and support.

Abstract: An ice auger includes a pair of ice boring blades fixedly attached to the bottom of a straight inner auger drive bar. A brace and bit arrangement at the top of the drive bar is for rotating the drive bar and either forcing it down toward the ice to bore a cylindrical hole of predetermined diameter through the ice or to force it up away from the ice after the hole has been bored to ream out a portion of that hole to form an inverted funnel shape opening. A tubular outer sleeve surrounds the drive bar and is movable between an upper boring condition and a lower reaming condition with respect to the drive bar. Two slotted longitudinally extending ice reaming blades are pivotally mounted at their top portions to the ream control sleeve. A reaming blade camming support bar attached to a bottom portion of the drive bar carries camming pins slidable in the reaming blade slots.

Abstract: An apparatus and method for drilling a bore hole (B) along an underground arcuate path (P) between two surface locations (O,E). The bore hole (B) is drilled in one direction with a drill string (10) having a leading pipe section 12 with a drill bit (14) thereon. Drilling fluid is supplied to the drill bit (14) during the drilling operation. Upon completion of the initial bore hole (B), the hole (B) may be enlarged by a reamer (40). Then, a production conduit (38) is connected to the reamer (40) for being pulled by the drill string (10) through the enlarged bore hole (D). Cement is supplied through the drill string (10) for discharge at the reamer (40) into the bore hole (D) adjacent the leading end of the production conduit (38) and fills the annulus A between the conduit (38) and the inner peripheral surface of the enlarged bore hole (D). In one embodiment (FIG. 12), the drill string (10B) is encased in cement in the initial bore hole (B) and forms a casing for receiving a small diameter production cable.

Abstract: An existing underground sewer or other pipe is renovated by rupturing and radially expanding the pipe and installing a replacement pipeline within the ruptured pipe. The pipe is ruptured and radially expanded by introducing a plurality of radially expandable tubular members into the pipe so as to form a liner. Each member is then radially expanded so that the liner engages with and then ruptures the portion of the pipe adjacent thereto. The tubular members may be radially expanded by inflating a bag within the confines of the members.

Abstract: A cutter assembly for rotary boring of earth. The assembly comprises a rotating cutter having a shaft protruding from the ends of the cutter; and a mounting member for the rotating cutter. The mounting member comprises two legs the ends of which are provided with counter surfaces for the ends portions of the shaft. The assembly further comprises fastening elements provided with a counter surface, the fastening elements being fitted at the ends of the legs for fastening the shaft to the mounting member. In order to provide a self-adjusting and reliable assembly which prevents the turning movement of the shaft, the curvature of the middle portion of the counter surface of the fastening element is so formed that a gap narrowing in the direction of the periphery of the shaft is defined between the shaft and the middle portion of the counter surface of the fastening element. A clutching part extending in the radial direction is arranged at the end of the shaft.

Abstract: The stabilizer extensions are brackets with rollers employed for stabilizing a large boring head when drilling a bore hole in the earth. A hub is provided for attachment to the head. The hub has a plurality of mounting plates located around its axis and radially outward therefrom. Each of the brackets has a bracket mounting plate at one end and a roller mounting plate at the other end. A roller is attached to each of the roller mounting plates for engaging the earth for stabilizing the head. The axis of each of the rollers defines a scalene triangle with two side edges of the bracket mounting plate of its extension bracket. The bracket mounting plate of each of the extension brackets is adapted to be attached to any of the hub mounting plates in a first position or turned 180.degree.

Abstract: An apparatus and method for drilling a pilot bore hole (B) along an underground arcuate path (P) between two surface locations (O, E). The pilot bore hole (B) is drilled in one direction with a drill string (10) having a leading pipe section (10A) of a reduced diameter to provide increased flexibility. Upon completion of the pilot bore hole (B), a reamer (48) connected to a product conduit (46) is connected to the drill string (10). Drill string (10) pulls the reamer (48) and product conduit (46) along the pilot bore hole (B) in an opposite direction for enlarging the bore hole (B) to receive the product conduit (46). A spud bit (34) has a flat or blunt leading end portion (34A) with a discharge opening (34D) therein to discharge high velocity drilling fluid into the formation at a location offset from the longitudinal axis of the drill string (10) to assist in guiding the drill string (10). An in-hole hydraulic motor (70) is provided in an embodiment (FIG.

Abstract: An apparatus and method for withdrawing existing outdated water pipe provides a frame assembly for mounting in a first shaft excavated at the water pipe. The frame includes a ram for inserting and withdrawing rod sections from the water pipe. A head assembly for mounting on the rods includes leaf spring centering devices and a plurality of single tooth dogs spring biased outwardly. When inserted into the existing pipe, the dogs spring outwardly so that the teeth engage a radially end face at the far end of a pipe section so the pipe section and head can be withdrawn. A severing device for clamping and fracturing a portion of the pipe withdrawn into the shaft is positioned adjacent a front face of the frame.

Abstract: A cable following apparatus has a rotating annulus at the front portion of its main body where a cylindrical axial opening of the body passing over a cable first comes in contact with concentric neutral wires. The annulus, by rotating in the direction of the neutral wrapping wires, has the effect of wrapping down any wires that are broken. Further, a helical groove in the annulus extends forward beyond a static cutter plate providing a front surface of the main body. The end of the groove rotates slightly behind the static cutting surface of the plate. Wires that are broken and pulled away from the cable are picked up by the groove and carried to a position where they are cut off by the force of the side of the helical groove pressing them against the static cutter surface of the plate.

Abstract: An excavating and propelling machine for laying pipelines underground has a plum-pudding stone crusher device comprising a plurality of rod-shaped rotary teeth formed integrally on the rear face of a disk-shaped rotating cutter head in a manner of extending radially at uniform intervals spaced apart from one another and a plurality of rod-shaped stator teeth formed integrally on the front surface of an annular front face plate in a manner of extending radially at uniform intervals space apart from one another. The rotary teeth and the stator teeth are disposed in the vicinity of each other.

Abstract: The technique for replacing an existing underground cable and a specific apparatus for doing so are disclosed herein. The apparatus includes a main body or cable follower which is interconnected with the cable to be replaced for slidable movement along the latter. At the same time, the apparatus provides means for reaming around the cable, preferrably by means of one or more fluid jets. Once the soil surrounding the cable has been loosened using this apparatus, the cable can be easily pulled out of the ground. At the same time, the replacement cable can be attached to the existing cable and pulled into its place.

Abstract: A cable following apparatus especially suitable for replacing existing underground cable is disclosed herein. This apparatus includes a tubular main body disposed around and movable along a particular cable in a forward direction while an arrangement of water jets are used to cut through the soil surrounding the cable in front of the forwardly moving main body. At the same time, a high pressure stream of air or similar gas is directed into a circumferential area between the front end of the main body and the cable in a way which is intended to prevent particulate material from passing therebetween and damaging or otherwise disrupting operation of the apparatus.

Abstract: Tunnels are constructed by freezing soil and removing frozen soil between starting and end shafts of the tunnels. Tunnels are driven in an uncomplicated manner in rapidly changing soils without auxiliary construction means. A hole is bored in or near the planned axis of the intended tunnel between starting and end shafts. A soil freezing work pipe is inserted into the hole. The pipe is cooled by a cooling agent. The soil freezing work pipe continues to be cooled until an ice and frozen soil mass has formed around the work pipe, which frozen mass has a diameter which is larger than that of the planned tunnel. Frozen soil is subsequently excavated, leaving a frozen soil lining, which is immediately supported by a primary support lining or a permanent lining.

Abstract: The technique for replacing an existing underground cable and a specific apparatus for doing so are disclosed herein. The apparatus includes a main body or cable follower which is interconnected with the cable to be replaced for slidable movement along the latter. At the same time, the apparatus provides means for reaming around the cable, preferrably by means of one or more fluid jets. Once the soil surrounding the cable has been loosened using this apparatus, the cable can be easily pulled out of the ground. At the same time, the replacement cable can be attached to the existing cable and pulled into its place.

Abstract: This invention relates to large diameter raise bore rock bits. The invention comprises a means in which extensions may be attached to the outer diameter of the body of the rock bit, thus providing a variable diameter raise bore rock bit. The extensions are mounted to the primary body of the bit such that compressive loads are imposed on the attachment means. These compressive loads are transmitted from the extensions of the body by designing the extension portions of the bit such that they interlock to the basic bit body. The mating surfaces of the attachment means transmit predominantly compressive loads acting substantially normal to the load bearing surfaces. The attachment means are further designed to increase the grip of the extended bit portions as increased loads are applied to the body of the rock bit.

Abstract: There is described a new and improved method and apparatus for boring subterranian holes between horizontally spaced locations, comprising a broaching head having a first trailing and a second leading end for cutting a bore hole through the ground, a rod string releasably connectible to the first end thereof for pushing the broaching head through the ground; a guiding head cooperating with the broaching head for guiding the movement of the broaching head between the horizontally spaced locations, and extruders to extrude the incised core of the bore. The broaching head is pushed between the locations to cut a core, which passes through the head, by forming first and second coaxial incisions, whereby subsequent removal of the core is facilitated.

Abstract: A drilling rig for drilling a selected underground path is provided. The drilling rig includes a pipe handling apparatus having a hydraulic cylinder and ram mounted on an inclined ramp over a substructure wherein rooms for housing supplies and control equipment are provided. Methods for preparing an arcuate path opening, or for placing a pipeline and laying a cable wherein all pulling and pushing of pipe is accomplished by the hydraulic pipe handling apparatus are also provided.

Abstract: A method for drilling hard material such as rock by fragmenting the rock by impact in selected spaced-apart areas and simultaneously fragmenting the rock by shear between the selected areas. The invention also covers a drill head with particularly arranged impact hammers for carrying out the method, and a drill unit incorporating the drill head.

Abstract: A cable following apparatus especially suitable for use in replacing existing underground cable by reaming around and along the length of the cable is disclosed herein. This apparatus includes a main body or cable follower which is interconnected with the cable to be replaced for slidable movement along the latter. In order to accomplish this, the apparatus includes a specifically designed mechanism for releasably gripping the cable at least at one end preferably two points along the cable in a specifically controlled fashion. At the same time, the apparatus provide means for reaming around the cable, preferably by means of one or more floor jets. Once the soil surrounding the cable has been loosened using this apparatus, the cable can be easily pulled out of the ground. A replacement cable can be attached to the existing cable and therefore pulled into place.

Abstract: A directional drill attached to a drill string having periodic concentric collars is advanced in an inverted arcuate path to form a pilot hole underneath an obstacle followed by a larger concentric washover pipe. When the washover pipe reaches the surface on the other side of the obstacle a first reamer is attached to the end of the washover pipe exiting the drilling path, a second reamer of smaller diameter than the first reamer is attached to the other end of the first reamer by means providing for some separation between the two reamers, and a production casing of smaller diameter than the second reamer is attached to the other end of the second reamer with a swivel. The remaining length of the first portion of casing is supported some distance above the ground on rollers located above and beyond the exit point of the pilot hole. The reamers are operated by rotating the washover pipe and simultaneously drawing the washover pipe through the pilot hole.

Abstract: A boring head for reaming a pre-drilled hole in raise boring or for similar earth cutting operations comprising a plurality of roller cutters (13, 14), each of which being rotatably journalled over a bearing system. The bearing system comprises a split roller bearing (60) having axially spaced rollers (62, 63) which are separated by a loose guide ring (69).

Abstract: A method and a cutter for producing a large cavity filled with a uniform bed of rubblized oil shale or other material, for in situ processing. A raise drill head (72) has a hollow body (76) with a generally circular base and sloping upper surface. A hollow shaft (74) extends from the hollow body (76). Cutter teeth (78) are mounted on the upper surface of the body (76) and relatively small holes (77) are formed in the body (76) between the cutter teeth (78). Relatively large peripheral flutes (80) around the body (76) allow material to drop below the drill head (72). A pilot hole is drilled into the oil shale deposit. The pilot hole is reamed into a large diameter hole by means of a large diameter raise drill head or cutter to produce a cavity filled with rubble.

Abstract: The technique for replacing an existing underground cable and a specific apparatus for doing so are disclosed herein. The apparatus includes a main body or cable follower which is interconnected with the cable to be replaced for slidable movement along the latter. At the same time, the apparatus provides means for reaming around the cable, preferrably by means of one or more fluid jets. Once the soil surrounding the cable has been loosened using this apparatus, the cable can be easily pulled out of the ground. At the same time, the replacement cable can be attached to the existing cable and pulled into its place.

Abstract: A bit connectible from the lower end of a rotatably powered drill stem for enlarging a preformed pilot hole includes a cutter carrier frame on which are mounted a plurality of roller cutters having peripheral cutting edges which sweep concentric circles upon rotation of the raise drilling bit. The circles swept by the cutters collectively define a generally dome-shaped cutting profile of constantly changing curvature which forms a segment of a spiral curve so that as the cutting profile extends radially outwardly from the drill stem, its curvature progressively decreases. The rotating cutter carrier frame structure drives a flywheel assembly at increased speed through the intermediacy of a step-up drive system composed of two planetary gear drives coupled in tandem.

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 raise bit (10) is constructed with a plurality of housings (30) secured to cutter carrier frame (14) and disposed about drive stem (12). Housings (30) include a rectangularly-shaped mounting box (48) for rotatably supporting an outboard roller cutter (28). Each housing (30) also includes an upright wall (34) having an upwardly tapered lug (40) extending along the upper edge portion thereof for seating within a correspondingly shaped groove (82) formed along the underside of shoulder section (78) of an L-shaped hanger bracket (68). A roller shell (72) is antifrictionally mounted on a spindle (70) extending outwardly from an upright section (76) of hanger bracket (68). Bracket (68) is held in hooked relationship over lug (40) by a pair of capscrews (74) extending downwardly through clearance holes formed in upright section (76) and engaging within a lower portion of upright wall (34).

Abstract: A directional drill attached to a drill string having periodic concentric collars is advanced in an inverted arcuate path to form a pilot hole underneath an obstacle followed by a larger concentric washover pipe. When the washover pipe reaches the surface on the other side of the obstacle a first reamer is attached to the end of the washover pipe exiting the drilling path, a second reamer of smaller diameter than the first reamer is attached to the other end of the first reamer by means providing for some separation between the two reamers, and a production casing of smaller diameter than the second reamer is attached to the other end of the second reamer with a swivel. The remaining length of the first portion of casing is supported some distance above the ground on rollers located above and beyond the exit point of the pilot hole. The reamers are operated by rotating the washover pipe and simultaneously drawing the washover pipe through the pilot hole.

Abstract: An earth boring drill bit, particularly for large diameter shafts, has a cutter assembly with improved bearing and seal arrangement and an improved cutting insert arrangement. A cutter assembly has an axle with an enlarged central portion and reduced portions on both sides. A cutter sleeve is carried on bearings by the central portion of the axle. An annular member with a central bore is secured to each side of the cutter sleeve. A metal face seal is secured between the reduced portion and the central bore on each side. The cutter contains rows of hard metal inserts secured in holes in the exterior. To reduce tracking, the inserts within a row are separable into groups with varied pitch within each group. The groups cycle with two groups having a gradual increase in pitch and two groups having decreasing pitch.

Abstract: A hydraulic earth boring machine for forming conduit passageways beneath established surfaces such as roadways, walkways, or the like. The boring machine includes a hydraulic cylinder having an open axial passageway for receiving a boring shaft. A drive cylinder surrounds the boring shaft and is driven by the hydraulic cylinder. A gripping assembly is mounted upon a trailing end of the drive cylinder and selectively couples the drive cylinder to the boring shaft. An elevating and vertical aiming assembly is mounted upon the hydraulic cylinder for facilely providing positioning of the boring machine, in situ, within an earth trench. In addition, an axial bracing and horizontal angling assembly is mounted upon the cylinder for mounting the boring machine within the trench adjacent an established surface.

Abstract: A non-rotating stabilizer for raise boring having a diameter substantially equal to the raise head and which is positioned below the raise head so as to follow it as the hole is bored is disclosed. A second raise head having a larger diameter than the stabilizer may be positioned below the stabilizer.

Abstract: A bore head for reaming a pre-drilled hole in raise boring or for similar earth cutting operations comprising at least two sets of roller cutters. The roller cutters in the same set of cutters have the same number of rows of cutting means. The roller cutters are mounted in pairs on each side of the rotational axis of the bore head. During rotation of the bore head the cutting means move along concentric circles. In order to change the distance between two consecutive circles a roller cutter in one of the pairs of cutters is replaced by a roller cutter of the other set of cutters.

Abstract: A raise head having a multiplicity of cutters for enlarging a pilot hole into a larger diameter hole by disintegrating the earth formations that surround the pilot hole is provided that will require lower cutter loads to penetrate the formations being bored by directing the rock fracture planes toward the pilot hole forcing the rock to yield with less input energy. The cutters are positioned on the raise head to provide an earth formation contact profile with a major portion of said earth formation contact profile extending outward and upward from said pilot hole. The included angle between the major portion of the earth formation contact profile and the axis of the pilot hole is less than 90.degree..

Abstract: A method of boring holes in the ground, which holes are open at both ends, includes forming an open-ended pilot bore by means of a first self-propelled displacement hammer of smaller diameter. Next a cable is introduced through the pilot bore and then the diameter of the pilot bore is increased to form the hole by means of a second displacement hammer of greater diameter. The second displacement hammer is guided through the pilot bore by pulling it with the cable which for this purpose is attached to the leading end of the second hammer.

Abstract: An earth boring drill bit for large diameter shafts has an improved cutter arrangement. The drill bit has a cutter support member with a number of cutters mounted to it for disintegrating the earth formation face. At least one inner cutter is mounted near the center for cutting the center area. A number of gage cutters are mounted at the periphery to cut the gage area of the shaft. A number of intermediate cutters are spaced between the inner and gage cutters. Each intermediate cutter overlaps one-half of its width with an adjacent intermediate cutter.

Abstract: A raise bit is disclosed for enlarging a pilot hole into a larger diameter hole by disintegrating the earth formations surrounding the pilot hole. The raise bit includes a removable drive stem for enabling the raise bit to be transported through small drifts. The drive stem is attached to a thrust bearing plate which, in turn, is interconnected to a main bit body. The bit body extends around the drive stem and includes a plurality of rolling cutters for contacting and disintegrating the earth formations surrounding the pilot hole. The interconnection between the thrust bearing plate and the bit body is accomplished by means of a flexible shock absorbing member which is bonded to the plate and bit body. This flexible interconnection functions to absorb the bending and impact type loads acting on the bit body. A safety mechanism is provided to limit the amount of relative axial movement of the flexibly interconnected members should the bonded interconnections separate.

Abstract: A large diameter earth boring drill bit has a cutter mounting system that protects the cutter mounts from formation damage. The drill bit is of the type having a cutter support plate adapted to be secured to a string of drill pipe. A cutter shell is rotatably mounted on a bearing carrier and supported by a cutter mount that is secured to the cutter support plate. The cutter mount has two legs spaced apart, each leg having a slot for receiving a lug that extends from each end of the bearing carrier. The legs and lugs have apertures, with a wedge connector for insertion through for connecting the bearing carrier to the cutter mount. A protector member extends from at least one end of the bearing carrier, with the lug extending from the protector member into the slot. The protector member has a surface on each side of the lug that extends over and protects the end of the leg on each side of the slot from formation damage.

Abstract: A reamer bit for raise boring in rock, of the type comprising a body on which a number of rolling cutters with cutting inserts are rotatably mounted for contact with and disintegration of the rock, and a detachable stem mounted in a central bore on the body and adapted to be received in a pilot hole drilled in advance in the rock. The stem has two cylindrical portions, an upper one of which having a smaller diameter than a lower one thereof. The bore in the body has corresponding upper and lower cylindrical portions surrounding the stem. The upper cylindrical portions of the body and the stem define upper stem restraining surface means. The lower cylindrical portions of the body and the stem define lower stem restraining surface means. The stem at its lower portion is provided with a flange abutting the body from below and supporting it axially. The upper and lower restraining surface means together comprise a substantial axial portion of the part of the stem that is surrounded by the bore.

Abstract: A raise bit is disclosed for enlarging a pilot hole into a larger diameter hole by disintegrating the earth formations surrounding the pilot hole. The raise bit includes a removable drive stem for enabling the raise bit to be transported through small drifts. The drive stem is attached to a thrust bearing plate which, in turn, is interconnected to a main bit body. The bit body extends around the drive stem and includes a plurality of rolling cutters for contacting and disintegrating the earth formations surrounding the pilot hole. The interconnection between the thrust bearing plate and the bit body is accomplished by means of an annular shock absorbing member made of polyurethane. The elastomeric shock absorbing member has a substantially toroidal configuration and is designed and dimensioned to transfer all of the thrust and torsional loads passing from the drive stem and thrust bearing plate to the bit body, while absorbing a large portion of the impact type loads acting on the drill.

Abstract: A raise bit is disclosed for enlarging a pilot hole into a large diameter hole by disintegrating the earth formations surrounding the pilot hole. The raise bit includes a removable drive stem for enabling the raise bit to be transported through small drifts. The drive stem is attached to a thrust bearing plate which, in turn, is interconnected to a main bit body. The bit body extends around the drive stem and includes a plurality of rolling cutters for contacting and disintegrating the earth formations surrounding the pilot hole. The interconnection between the thrust bearing plate and the bit body is accomplished by means of an annular shock absorbing ring made of polyurethane. Means are also provided to transport fluid from the interior of the drive stem to contact the rolling cutters on the bit body. These means comprise a fluid passage way extending through the interior of the drive stem.

Abstract: A raise boring system is provided that allows the raise boring head to be easily and efficiently lowered back through the completed raise hole. The raise head includes a multiplicity of rolling cutters positioned in saddles that are firmly affixed to the body of the raise head. These fixed saddles and rolling cutters comprise the primary cutting stage of the raise head. A multiplicity of retractable gage cutters are located radially outside of the primary cutting stage. The retractable gage cutters comprise rolling cutters positioned in moveable saddles. The moveable saddles and rolling cutters can be selectively withdrawn inside the primary cutting stage. A hydraulic-pneumatic system is provided for withdrawing the retractable gage cutters.

Abstract: A removable shirttail of an earth boring tool, such as a hole opener, protects the seals and bearings of an associated cutter. In one embodiment, the shirttail attaches to a journal or mounting shaft of the cutter by threaded fasteners. In an alternate embodiment, different threaded fasteners that attach the journal to an associated leg of the tool cooperate with the cutter and the leg to clamp the shirttail between the journal and the leg. A wedge-shaped boss of the shirttail faces the wall of the bore being opened. A V-shaped saddle in the boss receives a complementary lug of the journal. The lug of the journal also mates with a complementary notch of the leg to prevent journal rotation. The removal of the theaded fasteners that attach the journal to the leg allows spacers or shims to be withdrawn, which in turn permits the cutter, journal, and shirttail to be moved along the journal axis to clear a nose of the journal from a bore in a central body of the tool.

Abstract: A drill hole in a rock body is collared by drilling a pilot hole into a tunnel, advancing the pilot drill across the tunnel to drill a hole in the opposite wall of the tunnel aligned with the pilot hole, mounting the borer head on an arbor located across the tunnel in both holes, rotating the borer head to collar the hole, and detaching the borer head from the arbor.

Abstract: A raise bit for enlarging a pilot hole into a larger diameter hole by disintegrating the earth formations that surround the pilot hole is provided with a cutter arrangement that provides a continuous angle bottom configuration in the range of 134.degree. to 60.degree..

Abstract: A drill bit is shown for enlarging a pilot hole into a larger diameter hole by disintegrating the earth formations that surround the pilot hole. The bit includes a cutterhead with a multiplicity of saddles containing rolling cutters for contacting and disintegrating the formations that surround the pilot hole. The rolling cutters are mounted so that the cutter face profile of the cutters extends in a uniform manner to the edge of the pilot hole and eliminates uncut bottom. A drive stem or stinger projects from the cutterhead. The lower portion of the drive stem or stinger comprises extensions that reach over or "bridge" the inner legs of the center saddles and extend into the available vacant areas between the saddles for attachment to the body of the cutterhead.

Abstract: The body of a raise boring head is produced from a truncated cone. A variety of efficient and economical methods such as spin-forming, casting, rolling, etc. may be used in producing the truncated cone body. A multiplicity of rolling cutters positioned in cutter saddles are mounted on the truncated cone body. The mounting surfaces for the cutter saddles are on a continuous plane. The continuous plane can be produced on the truncated cone body in one turning operation. The raise boring head is self-cleaning due to the natural tendency of the cuttings to slide toward the periphery of the truncated cone body surface. The overall gross weight of the raise boring head is reduced and the strength-to-weight ratio is increased. The structural rigidity of the raise boring head is improved even though many of the structural components used in prior art raise boring heads have been eliminated.

Abstract: A raise boring system is provided for boring raise holes wherein the finished raise holes have portions of different diameters. The system includes a raise head with a central drive stem defining an axis of rotation. Primary cutter means are positioned on the raise head for disintegrating the earth formations out to a first radial distance from said axis of rotation. Expanding secondary cutter means are positioned on the raise head for selectively disintegrating earth formations from said first radial distance out to additional and greater radial distances from said axis of rotation. The expanding secondary cutter means may be selectively located in a first position either beneath or in the same plane as the primary cutter means during boring at said first radial distance from said axis of rotation and selectively located in additional positions for boring at greater radial distances from said axis of rotation.

Abstract: An insert cutter for earth boring includes a plurality of skewed inserts for contacting the earth formations being bored. At least one annular row of tungsten carbide inserts are positioned in the cutter body. Each insert has an elongated body and a formation contacting head. The elongated body is mounted in a socket in the cutter body and the formation contacting head projects from the cutter body. The inserts are installed on the cutter body such that the inserts axes are angularly offset between one-half to thirty degrees from the rotational axis of the cutter.

Abstract: A directional drill attached to a drill string having periodic concentric collars is advanced in an inverted arcuate path to form a pilot hole underneath an obstacle followed by a larger concentric washover pipe. When the washover pipe reaches the surface on the other side of the obstacle a first reamer is attached to the end of the washover pipe exiting the drilling path, a second reamer of smaller diameter than the first reamer is attached to the other end of the first reamer by means providing for some separation between the two reamers, and a production casing of smaller diameter than the second reamer is attached to the other end of the second reamer with a swivel. The remaining length of the first portion of casing is supported some distance above the ground on rollers located above and beyond the exit point of the pilot hole. The reamers are operated by rotating the washover pipe and simultaneously drawing the washover pipe through the pilot hole.