Abstract: A boring tool moves having a pitch orientation, a yaw orientation and a roll orientation and is steerable underground using the roll orientation. A maximum drill string curvature is established for steering. The boring tool is advanced over a path segment. An averaged roll characteristic is determined for movement of the boring tool along the path segment. A path segment pitch orientation is established based on at least one measured pitch orientation along the path segment. Using the maximum drill string curvature in combination with the averaged roll characteristic and the path segment pitch orientation, the yaw orientation is determined. The averaged roll characteristic is determined based on a series of incremental roll measurements that are spaced across the path segment. A set of coupled ordinary differential equations is used to characterize movement of the boring tool.

Abstract: This invention presents a projection-receiving surface that has a surface having an undulating contour. The undulating contour comprises a plurality of alternating convex cylindrical surface segments and concave cylindrical surface segments. The convex cylindrical surface segments and concave cylindrical surface segments of the undulating contour of the surface arranged with cylindrical axes in a direction. The surface can further have an additional surface feature comprising striations, cusps, and/or nanoflaked reflector leaves. The striations are arranged crosswise to the undulating contour. The surface can be a reflection surface of a front projection-receiving surface.

Abstract: Location determination is performed using a transmitter including an elongated generally planar loop antenna defining an elongation axis. The elongation axis is positioned along at least a portion of a path. A magnetic field is then generated which approximates a dipole field. Certain characteristics of the magnetic field are then determined at a receiving position radially displaced from the antenna elongation axis. Using the determined certain characteristics, at least one orientation parameter is established which characterizes a positional relationship between the receiving position and the antenna on the path. The magnetic field may be transmitted as a monotone single phase signal. The orientation parameter may be a radial offset and/or an angular orientation between the receiving position and the antenna on the path. The antenna of the transmitter may be inserted into a first borehole to transmit the magnetic field to a receiver inserted into a second borehole.

Abstract: An arrangement is described for tracking a positional relationship between a boring tool and at least one in-ground line. A first transmitter generates a magnetic locating field from one of the boring tool or at least an underground length of the line. A receiver is carried by the boring tool if the field is generated from the line, or connected to the line if the field is generated from the boring tool, for detecting an intensity of the magnetic locating field indicative of the positional relationship between the boring tool and the line. A second transmitter is carried by the boring tool for producing a locating signal. A portable locator uses the locating signal to determine a position of the boring tool and indicates the detected intensity of the magnetic locating field.

Abstract: A boring tool is moved through the ground within a given region along a particular path. The boring tool is moved in cooperation with moving a portable locator to establish a series of boring tool locations of the boring tool on the particular path. As at least one location of the series of locations is established, the location and a time stamp are electronically recorded to designate at least a time at which the location was recorded.

Abstract: A drive train is used at least including an input shaft and an output shaft. A clutch member is rotatable by a clutch shaft about an axis of rotation. The clutch shaft is supported for lateral movement along the axis of rotation to move the clutch member to cooperate with the drive train at a first lateral position to cause the output shaft to turn and to move the clutch member to a second lateral position to disengage the output shaft from rotation of the input shaft. A permanent magnet is supported by one end of the clutch shaft and arranged for receiving an external magnetic biasing force along the axis of rotation to selectively move the clutch member between the first and second lateral positions. A traveling shaft can be used to support a selected gear for movement by the permanent magnet to implement transmission and reversing configurations.

Abstract: A boring tool moves having a pitch orientation, a yaw orientation and a roll orientation and is steerable underground using the roll orientation. A maximum drill string curvature is established for steering. The boring tool is advanced over a path segment. An averaged roll characteristic is determined for movement of the boring tool along the path segment. A path segment pitch orientation is established based on at least one measured pitch orientation along the path segment. Using the maximum drill string curvature in combination with the averaged roll characteristic and the path segment pitch orientation, the yaw orientation is determined. The averaged roll characteristic is determined based on a series of incremental roll measurements that are spaced across the path segment. A set of coupled ordinary differential equations is used to characterize movement of the boring tool.

Abstract: A method is described for use with first and second in-ground cables such that, when the first cable is driven at a locating signal frequency to emit a locating signal in an electromagnetic form, the locating signal can be coupled to the second cable to cause the second cable to generate a false locating signal. The method includes generating the locating signal frequency. A reference signal is produced. The locating signal frequency is impressed on the reference signal in a way which provides for distinguishing between the locating signal and the false locating signal. The locating signal frequency and the reference signal are summed to produce a summer output. The summer output is coupled onto the first cable such that the first cable emanates the locating signal and the reference signal, and the reference signal can be received for distinguishing between the locating signal and the false locating signal.

Abstract: Tension monitoring is described using a sensor which may exhibit an offset for which compensation may be provided to produce a zero voltage amplified output or to increase dynamic range. An arrangement determines whether a power reset is responsive to a battery bounce such that an initially-measured system start-up parameter can be retained. The start-up parameter is automatically saved at start-up if the power reset is responsive to a start-up from a shut-down condition. The start-up parameter may be a zero tension amplified output responsive to the sensor offset at zero tension. Protection of a tension data set is provided such that no opportunity for altering the data set is presented prior to transfer of the data set. A housing configuration forms part of an electrical power circuit for providing electrical power to an electronics package from a battery.

Abstract: A method is described for tracking the position, orientation and/or guiding a transmitter as it moves through the ground in a region. The transmitter transmits an electromagnetic locating signal received by a detector. The detector, with the transmitter at a start position, receives the signal to produce a first set of electromagnetic data. The transmitter moves to a second position. The detector receives the signal with the transmitter at the second position to produce a second set of electromagnetic data. Absolute positions of the detector and the transmitter are determined within the region using certain information including the first and second sets of electromagnetic data.

Abstract: In a system in which a transmitter is moved through the ground in a region, the system including a locating arrangement for tracking the position of and/or guiding the transmitter as the transmitter moves through the ground, a locating arrangement includes a configuration, forming part of the transmitter, for transmitting a locating signal at a current one of at least two locating frequencies and for transmitting a frequency designation identifying one of the frequencies of the locating signal. A locator receives the frequency designation and the locating signal for use in tracking the transmitter and a frequency tracking arrangement switches the locator between different ones of the locating frequencies, as the current locating frequency, based on said frequency designation. In one feature, the locating arrangement is configured for automatically switching between the frequencies based on the frequency designation.

Abstract: An arrangement and an associated method are described in which a boring tool is moved through the ground within a given region along a path in which region a cable is buried. The boring tool and the cable transmit a boring tool locating signal and a cable locating signal, respectively. Intensities of the boring tool locating signal and the cable locating signal are measured along with a pitch orientation of the boring tool. Using the measured intensities and established pitch orientation, a positional relationship is determined to relative scale including at least the boring tool and the cable in the region. The positional relationship is displayed to scale in one view. The positional relationship may be determined and displayed including the forward locate point in scaled relation to the boring tool and the cable. Cable depth determination techniques are described including a two-point ground depth determination method.

Abstract: A boring tool moves having a pitch orientation, a yaw orientation and a roll orientation and is steerable underground using the roll orientation. A maximum drill string curvature is established for steering. The boring tool is advanced over a path segment. An averaged roll characteristic is determined for movement of the boring tool along the path segment. A path segment pitch orientation is established based on at least one measured pitch orientation along the path segment. Using the maximum drill string curvature in combination with the averaged roll characteristic and the path segment pitch orientation, the yaw orientation is determined. The averaged roll characteristic is determined based on a series of incremental roll measurements that are spaced across the path segment. A set of coupled ordinary differential equations is used to characterize movement of the boring tool.

Abstract: A device rotates at least one static magnetic field about an axis, producing a rotating magnetic dipole field, and is movable in relation to the surface of the ground. The field is periodically sensed using a receiver to produce a receiver output responsive to the field. A positional relationship between the receiver and the device is monitored using the output. In one aspect, changing the positional relationship, by moving the device nearer to a boring tool which supports the receiver, causes an increase in accuracy of depth determination. In another aspect, determination of an actual overhead position of the boring tool, and its application, are described. Use of a plurality of measurements over at least one-half revolution of each magnet is disclosed. Establishing a surface radial direction toward a boring tool and resolution of multi-valued parameters is described. Calibration techniques, as well as a three transmitter configuration are also described.

Abstract: A portable locator and method for establishing the location of the cable line in a region which includes at least one generally straight electrically conductive cable line extending across the region from which cable line a locating signal includes a first arrangement for measuring a local flux intensity of the locating signal at a first above ground point within the region with the portable locator in a particular orientation at the first above ground point. A second arrangement uses the local flux intensity to establish a cable line angular orientation which limits the possible directions to the cable line relative to the particular orientation of the portable locator at the above ground point. A third arrangement uses the measured local flux intensity to establish an actual direction of the cable line that is selected from the possible directions based on certain characteristics of the locating signal.

Abstract: A drive train is used at least including an input shaft and an output shaft. A clutch member is rotatable by a clutch shaft about an axis of rotation. The clutch shaft is supported for lateral movement along the axis of rotation to move the clutch member to cooperate with the drive train at a first lateral position to cause the output shaft to turn and to move the clutch member to a second lateral position to disengage the output shaft from rotation of the input shaft. A permanent magnet is supported by one end of the clutch shaft and arranged for receiving an external magnetic biasing force along the axis of rotation to selectively move the clutch member between the first and second lateral positions. A traveling shaft can be used to support a selected gear for movement by the permanent magnet to implement transmission and reversing configurations.

Abstract: A drilling system performs underground boring using a drill rig and a boring tool which is configured for moving through the ground under control of the drill rig to form an underground bore. A monitoring arrangement, forming part of the system, includes a detection arrangement at the drill rig for monitoring at least one operational parameter to produce a data signal relating to at least one of a utility to be installed in the underground bore, the drill rig and the boring tool. A portable device forms another part of the system for receiving the data signal relating to the operational parameter for use by the portable device. A communication arrangement, for example using telemetry, transfers the data signal from the drill rig to the portable device. The operational parameter may be monitored for the purpose of preventing equipment failure.

Abstract: Location determination is performed using a transmitter including an elongated generally planar loop antenna defining an elongation axis. The elongation axis is positioned along at least a portion of a path. A magnetic field is then generated which approximates a dipole field. Certain characteristics of the magnetic field are then determined at a receiving position radially displaced from the antenna elongation axis. Using the determined certain characteristics, at least one orientation parameter is established which characterizes a positional relationship between the receiving position and the antenna on the path. The magnetic field may be transmitted as a monotone single phase signal. The orientation parameter may be a radial offset and/or an angular orientation between the receiving position and the antenna on the path. The antenna of the transmitter may be inserted into a first borehole to transmit the magnetic field to a receiver inserted into a second borehole.

Abstract: A boring tool is moved through the ground in a region which includes at least one electrically conductive in-ground line and which is subject to static magnetic fields including the magnetic field of the earth.

Abstract: Discriminating between a cable locating signal and a false cable locating signal is described. A reference signal, which contains a locating signal frequency impressed on it, is transmitted in a way which provides for detection of a phase shift between the locating signal and the false locating signal. Based on the phase shift, a receiver is used to distinguish the locating signal from the false locating signal.