Single cone rock bit having inserts adapted to maintain hole gage during drilling
AssigneeSmith International, Inc.
InventorsGeorge Bodo Witman, Peter Wilson, Scott D. McDonough, Michael A. Siracki
Life of this patent
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Abstract
A roller cone drill bit is disclosed which includes a bit body adapted to be coupled to a drill string. A bearing journal depends from the bit body. A single roller cone is rotatably attached to the bearing journal. The roller cone has a plurality of inserts disposed at selected positions about the cone. The journal defines a rotation angle with respect to an axis of rotation of the bit such that the roller cone includes a wall contact zone and a bottom contact zone. At least one of the inserts disposed in the wall contact zone has an extension portion terminating in a substantially planar upper surface.
Claims17
A roller cone drill bit, comprising:
- a bit body adapted to be coupled to a drill string;
- a bearing journal depending from the bit body;
- and
- a single roller cone rotatably attached to the bearing journal, the roller cone having a plurality of inserts disposed at selected positions thereon, the journal defining a rotation angle with respect to an axis of rotation of the bit such that a plurality of inserts in a wall contact zone have an extension portion, extending substantially to gage diameter, and terminating in a substantially planar upper surface, and
- wherein the plurality of inserts comprise a cutting flank rake angle related to a rotary position about the plurality of inserts, wherein the cuffing flank rake angle is in a range between about 0 and 40 degrees.
Dependencies are inferred from the claim text.