The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 05, 1988
Filed:
May. 22, 1986
Albert W Chau, Redmond, WA (US);
FlowMole Corporation, Kent, WA (US);
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.