Abstract: An assembly is disclosed herein for locating an underground object that is transmitting a relatively low frequency signal electromagentic field. Means are provided for scanning the earth's surface and homing in on the point where the magnetic field is strongest, and at that point, calculating the depth of the object based on the strength of the magnetic field.

Abstract: A swivel arrangement especially suitable for connecting the back end of a reaming tool to the front end of utility cable during installation of the latter underground is disclosed herein. This arrangement includes a swivel mechanism which is smaller in cross-section than the reaming tool and utility cable apparatus, for connecting the swivel mechanism to and between the reaming tool and utility cable, whereby to create an axially extending radial gap between the tool and cable. In accordance with one feature of the disclosed swivel arrangement, one end of the swivel mechanism is fixedly connected to the back end of the reaming tool to prevent relative lateral moement between the tool.

Abstract: A technique for providing a continuous underground tunnel between first and second spaced-apart points and for installing new cable, pipe or conduit is disclosed herein. This technique utilizes a boring device including means for boring through soil and a thrust conduit which pushes the boring device through the soil from a first starting point to a second end point as the device bores through the soil, whereby to form a tunnel between the two points. Thereafter, the cable to be installed within the tunnel is attached to the front end of the boring device and the latter is pulled back through the tunnel to its starting point by means of the thrust cable, thereby automatically pulling the new cable in place.

Abstract: The homing technique for directing an in-ground boring device through the ground from its particular location to a specific target point is disclosed herein. In accordance with this technique, an electromagnetic dipole field containing a predetermined homing signal is generated at the boring device and detected by a specifically configured receiving antenna arrangement at the target point or, in a preferred embodiment where the target point is below ground, at a ground level point directly above or beyond the target point. Means are provided in response to detection of the homing signal for producing an internal electrical signal containing certain information relating to the actual path taken by the boring device as compared to the path or course leading to the target point. The information from this latter signal is then transmitted by means of electromagnetic waves to a remote location where it is used to steer the boring device on a course toward the target.

Abstract: There is disclosed herein an apparatus for providing an underground tunnel utilizing a steerable pneumatically powered, elongated percussive downhole hammer having a forwardmost cutting bit which is asymmetrically configured with respect to the elongation axis of the hammer. This hammer is steered through the ground, that is, made to move along a straight path or a particular curved path, by controlling the way in which it is pneumatically powered and/or the way in which it is urged forward and/or the way in which its cutting bit is rotated.

Abstract: A system in which a boring tool is urged through the ground by means of a drill string in order to form an underground hole is disclosed herein along with an arrangement for obtaining certain information at the boring tool during operation of the boring tool. That arrangement includes a transducer carried by the boring tool for generating an AC signal containing desired information and means for connecting the transducer directly to the drill string and to the surrounding ground for transmitting the information containing signal to an above ground location.

Abstract: A technique for providing a continuous underground tunnel between first and second spaced-apart points and for installing new cable, pipe or conduit is disclosed herein. This technique utilizes a boring device including means for boring through soil and a thrust conduit which pushes the boring device through the soil from a first starting point to a second end point as the device bores through the soil, whereby to form a tunnel between the two points. Thereafter, the cable to be installed within the tunnel is attached to the front end of the boring device and the latter is pulled back through the tunnel to its starting point by means of the thrust cable, thereby automatically pulling the new cable in place.

Abstract: A technique for providing a continuous underground tunnel between first and second spaced-apart points and for installing new cable, pipe or conduit is disclosed herein. This technique utilizes a boring device including means for boring through soil and a thrust conduit which pushes the boring device through the soil from a first starting point to a second end point as the device bores through the soil, whereby to form a tunnel between the two points. Thereafter, the cable to be installed within the tunnel is attached to the front end of the boring device and the latter is pulled back through the tunnel to its starting point by means of the thrust cable, thereby automatically pulling the new cable in place.

Abstract: A method and apparatus for installing underground utilities using an offset head fluid jet drilling and reaming apparatus. The drill is maneuverable and provides means for remote sensing of orientation and depth. Embodiments are illustrated with single and multiple jet cutting orifices.

Abstract: A nozzle assembly for enlarging an inground passageway produced by, for example, a boring device is disclosed herein. The nozzle assembly is comprised of a longitudinally extending nozzle body defining an interior cavity adapted to receive fluid under pressure from an external source and at least one arrangement of outwardly facing adjacent stepped surfaces which provide longitudinally spaced cutting jets directed normal to the movement of the boring device and nozzle assembly as the latter moves through a previously provided passageway in order to progressively enlarge the passageway.

Abstract: A system in which an electrically conductive boring device is caused to move through the ground to provide an underground tunnel, to install underground utilities, or for any other reason. A technique for detecting if the boring device electrically engages an underground source of high voltage such as an existing underground utility line. This arrangement, is also suitable for detecting if other electrically conductive apparatus, structural member, or like means engages a similar underground source of high voltage includes means defining an electrically conductive path leading from the boring device or other such member to a grounding point sufficient to reduce to a negligible level any high voltage to which the device or like member may be subjected. The present technique monitors the current through the grounding path and indicates if the current level through the path reaches a predetermined threshold level which is selected to correspond with the presence of high voltage.

Abstract: A technique for providing a continuous underground tunnel is disclosed herein. This technique utilizes an elongated boring device including a forward facing, off-axis high pressure fluid jet which is rotated about the elongated axis of the device while the latter is urged forward through the soil, whereby to cause the device to bore a tunnel through the soil as it moves forward. In accordance with one feature of this technique, the boring device is steered by modulating the speed and/or the direction of rotation of its off-axis fluid jet in a way which depends upon the desired direction to be taken by the boring device within the soil. In accordance with another feature of the overall technique, the pitch angle of the boring device, as defined by its elongation axis, is monitored relative to a horizontal ground plane, independent of the roll position of the device.

Abstract: A method and apparatus for installing underground utilities using an offset head fluid jet drilling and reaming apparatus. The drill is maneuverable and provides means for remote sensing of orientation and depth. Embodiments are illustrated with single and multiple jet cutting orifices.