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Referenced by

Citing PatentFiling dateIssue dateOriginal AssigneeTitle
US397488627 Feb 197517 Aug 1976Directional drilling tool
US43343923 Apr 198015 Jun 1982A. B. Chance CompanyModular screw anchor having lead point non-integral with helix plate
US463887426 Jul 198327 Jan 1987Coalequip (Proprietary) LimitedDrill adaptor
US495363827 Jun 19884 Sep 1990The Charles Machine Works, Inc.Method of and apparatus for drilling a horizontal controlled borehole in the earth
US499350327 Mar 199019 Feb 1991Electric Power Research InstituteHorizontal boring apparatus and method
US514888031 Aug 199022 Sep 1992The Charles Machine Works, Inc.Apparatus for drilling a horizontal controlled borehole in the earth
US524202625 Mar 19927 Sep 1993The Charles Machine Works, Inc.Method of and apparatus for drilling a horizontal controlled borehole in the earth
US53223911 Sep 199221 Jun 1994Foster-Miller, Inc.Guided mole
US534188725 May 199330 Aug 1994The Charles Machine Works, Inc.Directional multi-blade boring head
US535025422 Nov 199327 Sep 1994Foster-Miller, Inc.Guided mole
US549218418 Feb 199420 Feb 1996Terra AG fuer TiefbautechnikEarth boring device
US559704612 Apr 199528 Jan 1997Foster-Miller, Inc.Guided mole
US579974027 Feb 19951 Sep 1998The Charles Machine Works, Inc.Directional boring head with blade assembly
US594132222 Jun 199824 Aug 1999The Charles Machine Works, Inc.Directional boring head with blade assembly
USRE3207612 Jun 19844 Feb 1986A. B. Chance CompanyModular screw anchor having lead point non-integral with helix plate
USRE3745019 Jan 200020 Nov 2001The Charles Machine Works, Inc.Directional multi-blade boring head
USRE3797525 Sep 20004 Feb 2003The Charles Machine Works, Inc.Directional boring head with blade assembly