Abstract: Boring apparatus for forming a generally horizontal underground passage for a utility conduit or the like that includes a tool head with elongated body structure and a cutting face of ellipto-conical form at one end of the elongated body structure. The cutting face has a major axis and a minor axis and cutting bit structure is fixed to and projects forwardly from the cutting face and extends substantially the full width of the cutting face generally along the major axis. The tool head also includes coupling structure for attaching the tool head to a drill string such that the cutting tool face is offset from the drill string axis. Structure in the cutting face defines a cutting fluid orifice adjacent the cutting bit structure for directing a high velocity jet of cutting fluid forwardly of the cutting tool face.

Abstract: Tool for slitting and laterally expanding underground steel gas mains and inserting replacement plastic piping into the spread apart pipeline has a forward end cylindrical portion mounting a single, rearwardly angled blade to make only one line of cut, and a conical pipe spreader portion at its rearward end. The conical spreader portion is eccentrically disposed with respect to the forward end cylindrical portion. A single roller type pipe slitter aligned with the fixed blade may be mounted on a removable extension of the forward end cylindrical portion, to initially groove and weaken the pipe along the intended line of cut. A pneumatically operated impact ram is attached to the rearward end of the tool, as is the leading end of the replacement piping. A wire cable pulls the tool through the underground pipe, thereby grooving, slitting and laterally expanding the pipe.

Abstract: A drilling attachment for a utility truck designed for digging pole holes for ordinary utility and telephone poles is disclosed herein. The attachment is intended to replace the auger portion of a conventional auger digger when it is necessary to drill through rock or other hard materials. The excavating method contemplated employs a three step process. First, a deep kerf is cut into the rock by a plurality of drill bits that are independently driven in a rotary/percussive manner while being rotated about the circumference of the kerf. The dust and rock fragments generated by this process are removed from the kerf by an air flushing/vacuum system, that also serves to cool the drill bits. Second, a hydraulic piston is inserted into the kerf and expanded, thereby applying a lateral force to the base of the resultant core causing it to break away from the surrounding rock. Finally an expandable plug is inserted into a pilot hole located at the center of the core.

Abstract: Pipe coupling apparatus including a tubular female coupling structure and a tubular male coupling structure sized to fit within and mate with the female coupling structure, one coupling structure including a housing and a locking ring that is radially deformable within an annular supporting groove of the housing, the other coupling structure including a tapered surface for biasing the ring to vary its radius as the coupling structures are brought together and an annular locking groove for receiving the ring when it is aligned with the locking groove as the coupling structures are moved further together and the ring springs back toward its undeformed shape, one coupling structure carrying an annular seal to provide a fluid-tight seal between said coupling structures.

Abstract: A drag bit excavating device comprising a core extending along an axis; a bit carrier supported on the core; cutter bits supported by the carrier along a three dimensional spiral having constant pitch and increasing radius along at least a portion of the axis, the carrier being relieved to provide radially extending spaces between the turns of the spiral; a frame supporting the core, carrier, and bits for rotation about and advance along the axis; and a drive to provide rotation, whereby the bits slot the material to be excavated while the material between portions of the resulting slot extends into the spaces to be subsequently broken away.

Abstract: A boring apparatus having a working member mounted for rotation on a lubricated bearing about a shaft member, the apparatus being of the type in which substantial radial and axial relative motion between said members occurs in response to radial and axial loading conditions encountered by the working member during operation in an abrasive laden external environment, including an improved seal assembly between the members for sealing the bearing from the environment while accommodating the radial and axial relative motion, the seal assembly comprising a seal carrier mounted in a space between the members, a dynamic seal element supported between the carrier and one of the members to form a dynamic seal therebetween, and a static seal element supported between the carrier and a radially extending surface of the other of the members, the dynamic seal element being axially slidable along the one member to accommodate the axial relative motion, the static seal element being deformable and radially slidable along t

Abstract: Boring apparatus having a plurality of hole-enlarging assemblies comprising shaft-mounted working members. In a convergent arrangement of the axes of the working members the assemblies are completed by insertion of the elongated shafts via a hollow space in the bottom connector, through passages in the frame. The upper ends of the shafts are shown held in holes in the frame, and the exterior upper and lower surfaces of the frame are shown as surfaces of revolution, free of wear points. The passages are shown to form cut-outs in the thread of the connector in the first preferred embodiment. In other embodiments the passages are formed through an extension of the frame preceding the connector, and a two-part connector assembly is provided, the passage entering a hollow space provided by the outer part.