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.

Date of Patent:
Mar. 19, 2002

Filed:

Mar. 15, 2000
Applicant:
Inventors:

Randy Runquist, Lovilia, IA (US);

Mark Van Houwelingen, Knoxville, IA (US);

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21B 4/06 ;
U.S. Cl.
CPC ...
E21B 4/06 ;
Abstract

A horizontal drilling machine for directionally drilling a drill string into the ground. The drill string includes a plurality of elongated members threaded together in an end-to-end relationship. The drilling machine includes a track, a rotational driver mounted on the track, and a thrust mechanism for propelling the rotational driver along the track. The rotational driver is used to rotate the drill string in forward and reverse directions about a longitudinal axis of the drill string. The drill string is rotated in the forward direction to thread the elongated members together, and rotated in the reverse direction to unthread the elongated members from one another. The drilling machine also includes a reverse torque limiter that prevents the rotational driver from applying a reverse torque to the drill string that exceeds a reverse torque limit. The reverse torque limit is less than a maximum reverse torque that can be generated by the rotational driver when the reverse torque limiter is deactivated.


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