# US 8,786,285 B2 · Apparatus for monitoring a positional relationship between a boring tool and an inground line > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,786,285 B2 - Document ID: US8786285B2 - Status: Granted - Kind: B2 - Application number: 13/462,735 - Filed: 2012-05-02 - Published: 2012-11-15 - Granted: 2014-07-22 - Earliest claimed: 1996-05-03 - Assignees: Merlin Technology, Inc. - Applicants: John E. Mercer; Albert W. Chau - Inventors: John E. Mercer; Albert W. Chau - Web page: https://patentgrep.com/patent/US8786285B2 ## CPC - G01V 3/15: specially adapted for use during transport, e.g. by a person, vehicle or boat - E21B 44/00: Automatic control systems specially adapted for drilling operations, i.e. self-operating systems which function to carry out or modify a drilling operation without intervention of a human operator, e.g. computer-controlled drilling systems; Systems specially adapted for monitoring a plurality of drilling variables or conditions - E21B 47/0232: at least one of the energy sources or one of the detectors being located on or above the ground surface - E21B 47/024: of devices in the borehole (determining slope or direction of the borehole E21B47/022) - G01V 3/081: {the magnetic field is produced by the objects or geological structures (characterised by the method of magnetic field measurement G01R33/00)} - G01V: GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS (means for indicating the location of accidentally buried, e.g. snow-buried, persons A63B29/02) - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract An apparatus monitors a positional relationship between a boring tool and an inground line and includes a transmitter to generate a magnetic locating field from one of either the boring tool or at least an underground length of the line. A receiver can be 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, to detect an intensity of the magnetic locating field to produce a signal indicative of the magnetic field intensity with the signal being responsive to the positional relationship between the boring tool and the line. A display produces an indication responsive to the signal based on the detected intensity of the magnetic locating field. ## Claims ### Claim 1 In a system in which a boring tool is moved from a drill rig through the ground by a drill string in a region which includes at least one electrically conductive in-ground line, an apparatus for monitoring a specific positional relationship between the boring tool and said line, said apparatus comprising: a transmitter to generate a magnetic locating field from one of either said boring tool or at least an underground length of said line; a receiver carried by said boring tool if said field is generated from said line, or connected to said line if said field is generated from said boring tool, to detect an intensity of said magnetic locating field to produce a signal indicative of said magnetic field intensity, said signal being responsive to the positional relationship between the boring tool and said line; and a display to produce at least one indication responsive to said signal based on the detected intensity of said magnetic locating field as generated from either one of said line or said boring tool. ### Claim 2 (depends on 1) The apparatus of claim 1 wherein said display is located at said drill rig. ### Claim 3 (depends on 1) The apparatus of claim 1 further comprising: a repeater that is responsive to said intensity indicative signal for receiving the intensity indicative signal from the boring tool and transferring the intensity indicative signal to the display at the drill rig and wherein said repeater is further configured as a locator for locating the boring tool. ### Claim 4 (depends on 1) The apparatus of claim 1 wherein said display includes an arrangement for establishing the specific positional relationship between said boring tool and said line. ### Claim 5 (depends on 1) The apparatus of claim 1 wherein the transmitter and the receiver are cooperatively configured to provide the detected intensity so as to be unambiguously representative of said specific positional relationship between the boring tool and the line. ### Claim 6 (depends on 1) The apparatus of claim 1 wherein the detected intensity indicated by said display represents a vector sum. ### Claim 7 (depends on 1) The apparatus according to claim 1 including a telemetry link forming one part of said receiver and forming another part of said display for transmitting the detected intensity from said boring tool or said line to said display. ### Claim 8 (depends on 1) The apparatus according to claim 1 wherein the transmitter is configured to transmit from the line and the receiver is carried by the boring tool. ### Claim 9 (depends on 1) The apparatus according to claim 1 wherein the transmitter is carried by the boring tool and the receiver is coupled to said line.