Patent Number: 7,786,732

Title: Apparatus for monitoring a positional relationship between a boring tool and an inground line

Abstract: In a system having a boring tool and an above-ground portable locator for locating the boring tool as moved by a drill string in a region which includes an in-ground line, an apparatus is described for monitoring the positional relationship between the boring tool and the line. The apparatus includes a transmitter for generating a magnetic locating field from one of the boring tool or 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 to produce a magnetic field intensity indicative signal that is indicative of the positional relationship between the boring tool and the line. A remote display indicates the detected intensity of the magnetic locating field.

Inventors: Mercer; John E. (Kent, WA), Chau; Albert W. (Woodinville, WA)

Assignee: Merlin Technology Inc.

International Classification: E21B 47/12 (20060101); G01V 3/06 (20060101); E21B 7/04 (20060101)

Expiration Date: 8/31/12018