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:
Aug. 06, 2002

Filed:

Jul. 06, 2000
Applicant:
Inventors:

Tom Roberts, Abbeymead, GB;

Steven Barton, Aldbourne, GB;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
E21B 1/016 ; E21B 1/046 ;
U.S. Cl.
CPC ...
E21B 1/016 ; E21B 1/046 ;
Abstract

The present invention is a drag-type drill bit for drilling a borehole in the earth. The bit is designed to rotate about a central axis of rotation and has a bit body having a leading face, an end face, a gauge region, and a shank for connection to a drill string, a plurality of nozzles in the bit body for delivering drilling fluid to the end face, a plurality of blades upstanding from the leading face of the bit body and extending outwardly away from the central axis of rotation of the bit. Each blade terminates in a gauge pad with a surface which faces a wall of the borehole. A first plurality of cutters are mounted on the blades at the end face of the bit body and a second plurality of cutters are mounted the gauge pads and arranged such that in operation, they cut the wall of the borehole. Each one of the second plurality of cutters has a backrake less than or equal to about 20 degrees. A plurality of non-cutting bearing element are mounted on the gauge pads in a trailing relationship relative to the rotation of the bit behind at least some of the second plurality of cutters. The surface of each gauge pad is relieved from the borehole by at least 3 mm.


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