Abstract: The invention provides a rock drilling bit with a plurality of cutting teeth raked into the cut of the drilling bit. Such teeth are oriented at an angle of at least about 30 degrees relative to an imaginary line normal to a front surface of the cutting head from which the cutting teeth project. Such an arrangement provides the desired shear cutting force against the rock face while simultaneously reducing the shock and vibration applied to sonde housing and the drill string. The bit according to the invention may further incorporate a rear, frustoconical crushing surface that defines a space or zone crescent-shaped in cross-section that narrows from front to rear, and an improved replacable tooth for use on a rock drilling bit.

Abstract: A drill head for an apparatus for directional boring according to the invention includes a bit, a holder for a device for detecting angular orientation of the bit, and a hammer including a striker for delivering impacts to the bit, wherein the bit assembly, holder and hammer are connected head to tail with the bit at a front end. The bit of the invention has a frontwardly facing main cutting surface having a plurality of main cutting teeth disposed thereon and a gage tower extending radially outwardly from the main cutting surface, which gage tower has at least one frontwardly facing gage cutting tooth thereon suitable for cutting over an angle defined by less than a full rotation of the bit. The device for detecting angular orientation is in a predetermined alignment with the gage tower so that it determines the orientation of the gage tower relative to the axis of rotation of the drill head.

Abstract: The invention provides a rock drilling bit with a plurality of cutting teeth raked into the cut of the drilling bit. Such teeth are oriented at an angle of at least about 30 degrees relative to an imaginary line normal to a front surface of the cutting head from which the cutting teeth project. Such an arrangement provides the desired shear cutting force against the rock face while simultaneously reducing the shock and vibration applied to sonde housing and the drill string. The bit according to the invention may further incorporate a rear, frustoconical crushing surface that defines a space or zone crescent-shaped in cross-section that narrows from front to rear, and an improved replacable tooth for use on a rock drilling bit.

Abstract: A drill head for an apparatus for directional boring according to the invention includes a bit, a holder for a device for detecting angular orientation of the bit, and a hammer including a striker for delivering impacts to the bit, wherein the bit assembly, holder and hammer are connected head to tail with the bit at a front end. The bit of the invention has a frontwardly facing main cutting surface having a plurality of main cutting teeth disposed thereon and a gage tower extending radially outwardly from the main cutting surface, which gage tower has at least one frontwardly facing gage cutting tooth thereon suitable for cutting over an angle defined by less than a full rotation of the bit. The device for detecting angular orientation is in a predetermined alignment with the gage tower so that it determines the orientation of the gage tower relative to the axis of rotation of the drill head.

Abstract: A drill head for an apparatus for directional boring includes a bit having a cutting portion for use in steering, such as a gage tower mounted with carbide studs, suitable for cutting both hard and soft rock, a holder for a device for detecting angular orientation of the bit, and a pneumatic hammer connected head to tail with the bit at the front end. The valve in the hammer initiates reciprocation of the hammer in response to rearward movement of the bit, such as in response to a pushing force exerted by the drill string. The drill string components are preferably keyed to one another so that the orientation of the cutting portion of the bit used for steering is automatically matched to the position of the sonde. The sonde may project laterally so that its mass centroid is on the opposite side of the cutting portion of the bit used for steering to provide better cutting action. Such a drill head is suited for drilling in soil, soft rock and hard rock conditions.

Abstract: A drill head for an apparatus for directional boring according to the invention includes a bit, a holder for a device for detecting angular orientation of the bit, and a hammer including a striker for delivering impacts to the bit, wherein the bit assembly, holder and hammer are connected head to tail with the bit at a front end. The bit of the invention has a frontwardly facing main cutting surface having a plurality of main cutting teeth disposed thereon and a gage tower extending radially outwardly from the main cutting surface, which gage tower has at least one frontwardly facing gage cutting tooth thereon suitable for cutting over an angle defined by less than a full rotation of the bit. The device for detecting angular orientation is in a predetermined alignment with the gage tower so that it determines the orientation of the gage tower relative to the axis of rotation of the drill head.

Abstract: A drill head for an apparatus for directional boring includes a bit having a cutting portion for use in steering, such as a gage tower mounted with carbide studs, suitable for cutting both hard and soft rock, a holder for a device for detecting angular orientation of the bit, and a pneumatic hammer connected head to tail with the bit at the front end. The valve in the hammer initiates reciprocation of the hammer in response to rearward movement of the bit, such as in response to a pushing force exerted by the drill string. The drill string components are preferably keyed to one another so that the orientation of the cutting portion of the bit used for steering is automatically matched to the position of the sonde. The sonde may project laterally so that its mass centroid is on the opposite side of the cutting portion of the bit used for steering to provide better cutting action. Such a drill head is suited for drilling in soil, soft rock and hard rock conditions.

Abstract: An improved drill bit for directional drilling includes a housing or headpiece having means at a rear end thereof for mounting the bit on a trailing component of a drill head, and passages for ejection of drilling fluid into a borehole. A first axle is mounted to extend forwardly from a front end of the housing, and a first roller is rotatably mounted on the first axle. The first roller has cutting projections such as carbide studs thereon and extends outside of the outer diameter of the housing by a distance which defines the size of the borehole when the drill bit is rotated over 360 degrees. A second axle is mounted to extend from the front end of the housing, and a second roller is rotatably mounted on the second axle at a position offset from the first axle. The second roller extends slightly outside of the outer diameter of the housing, but by a distance less than the distance the first roller extends outside of the housing.

Abstract: An improved jaw for a rod gripping device is provided including a front, rod engaging face with a plurality of teeth or studs made of a material harder than the jaw body, such as tungsten carbide, with the studs positioned to engage an outer rounded rod surface. In one embodiment, the studs are oriented radially inward toward a longitudinal axis defined by the rod engaging surface. The rod engaging face of the jaw may have a concave shape in its lengthwise direction, thus being adapted to grasp a cylindrical member such as a rod or pipe section. A tool for gripping a rod including a pair of jaws is also provided.

Abstract: An impact boring tool according to the invention suitable for using with a directional boring machine has a tubular housing and a head mounted at a front end of the housing. The head preferably includes a chisel configured for breaking loose rocks and stones encountered in soil. A striker is disposed within the housing for delivering an impact force to the head, either directly or through one or more intervening parts. A trigger mechanism causes the striker to deliver an impact to the head and chisel only when an external force exerted on the impact tool in its lengthwise direction exceeds a predetermined level. This predetermined level generally coincides with a maximum effective amount of pushing or pulling force for moving the tool through the ground exerted by an external device such as a directional boring machine.

Abstract: An adapter usable for interconnection of a pair of drill components according to the invention includes an elongated adapter body having a first end and a second end, wherein the first end includes one of (1) a tubular wall defining a socket that opens outwardly at one end of the adapter and having at least one transverse opening therethrough configured to receive a removable retainer for mechanically interlocking a projection in the socket, and (2) the projection which fits into the socket, which projection has at least one transverse opening therein to receive the removable retainer. The second end includes a connecting portion different from the projection and the tubular wall defining the socket, such as a threaded projection or recess. The adapter preferably has a lengthwise fluid passage through it suitable for passing lubricating drilling fluid through the adapter to a drill head or back reamer.

Abstract: The present invention provides a portable pulling apparatus suitable for mounting in an exit pit during installation of a pipeline. A portable pulling apparatus of the invention includes an elongated stake having a lower end portion configured for insertion into the ground and an upper end portion. A winch including a pulling cable is mounted on the upper end portion of the stake by a suitable fixture. The winch can then operate to exert a horizontal pulling force on a cable and is secured against movement when the lower end portion of the stake is inserted into the ground. Such a pulling apparatus can be used in a method of installing an underground pipe according to the invention.

Abstract: A ground piercing tool has an elongated tubular tool housing and a striker that reciprocates within an internal chamber of the housing. The striker impacts a front impact surface and drives the tool through the ground. An air distributing mechanism causes the striker to reciprocate in response to a supply of compressed fluid. An anvil providing a front impact surface is disposed in a front end opening of the tool housing. The anvil has a rear frustoconical portion that engages a like-shaped forwardly tapering inner wall of the housing and a lengthwise bore that has an enlarged diameter portion. A chisel is slidably disposed in the bore of the anvil and has an outwardly opening annular groove. A spring is confined in compression in a space defined by the annular groove of the chisel and the enlarged diameter portion of the anvil bore. The spring urges the rear end of the chisel to protrude rearwardly from the bore of the anvil a predetermined distance.

Abstract: The invention provides an improved apparatus for directional boring and in particular an improved system for boring through hard and rocky substrates frequently encountered when boring under obstacles such as roadways. According to one aspect of the invention, a directional drilling apparatus includes a drilling head having a front face angled relative to the lengthwise axis of the tool and configured for steering the drilling apparatus, a housing having an internal chamber for mounting an electronic locating device therein rearwardly of the drilling head for transmitting a signal indicating the orientation of the angled face of the drilling head, and a joint at which the drilling head is removably mounted to the housing of the locating device.

Abstract: The present invention provides a portable pulling apparatus suitable for mounting in an exit pit during installation of a pipeline. A portable pulling apparatus of the invention includes an elongated stake having a lower end portion configured for insertion into the ground and an upper end portion. A winch including a pulling cable is mounted on the upper end portion of the stake by a suitable fixture. The winch can then operate to exert a horizontal pulling force on a cable and is secured against movement when the lower end portion of the stake is inserted into the ground. Such a pulling apparatus can be used in a method of installing an underground pipe according to the invention.

Abstract: The invention provides an apparatus for mounting an electronic device therein for use in an underground boring machine. Such an apparatus includes an elongated housing having means at opposite ends of the housing for connecting the housing to other components of the boring machine and an elongated internal chamber configured to receive an electronic device such as a sonde therein and having an elongated access opening which extends along an exterior surface of the housing. A cover sized to close the access opening has edges that fit beneath one or more flanges of the housing. A retainer such as a roll pin is sized for insertion into openings in the cover and housing, which openings become aligned when the cover is positioned with the edges beneath the flange of the housing.

Abstract: A method and apparatus for replacement of an existing non-frangible pipeline includes creating open access to opposite ends of an pipeline and threading a cable having a wedge mounted thereon through the pipeline so that the wedge is positioned proximate one of the ends of the pipeline. The wedge is pulled through the pipeline from the other end of the pipeline so that the wedge slits the pipeline to form a slit pipe in a borehole. The slit pipe is removed from the borehole and a rear end portion of the slit pipe is attached to a front end portion of the replacement pipe . As the slit pipe is pulled out of the borehole, the replacement pipe is drawn into the borehole. The boring apparatus has a braided cable and a boring head having an expander sleeve and a lengthwise bore of sufficient diameter so that the cable can pass therethrough.

Abstract: A joint is provided for coupling a pair of elongated members such as a sonde housing and starter rod end to end. Such a joint includes a projection extending in a lengthwise direction from one end of one of the elongated members and a socket in an end of the other of the elongated members, which socket is sized to slidingly receive the projection. A set of alignable transverse openings are provided in the projection and in a wall defining the socket, which openings are configured to receive a removable retainer for mechanically interlocking the projection in the socket. An interlock mechanism, such as a spline and groove connection, prevents relative rotation between the elongated member (e.g., housing and starter rod) when the projection is fully inserted into the socket.

Abstract: In a method for making a self-propelled impact boring tool, the tool body is formed by swaging a steel tube to form the tapered nose of the tool. This results in less wasted steel as compared to conventional machining of a solid steel bar to form the body, which is the largest single part of the tool. The tool body may then be fitted with a tool anvil of slightly different dimensions than the forming anvil used during swaging to provide an interference fit.

Abstract: A pneumatic ground piercing tool has a head which can be removed and replaced with a replacement head of the same or different design. The detachable head is mounted on the an axial rod behind a threaded surface of the rod, and a nut is threadedly secured on the front threaded portion of the rod, whereby the head is clamped between a front end of the tool housing and the nut. The nut can be unscrewed from the rod to permit replacement of the head. A clamp-loading locking mechanism is used to secure the head to the nut to prevent the nut and head from loosening during operation.