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US 7,743,857 B2Granted
Cutting elements of gage row and first inner row of a drill bit
AssigneeSmith International, Inc.
InventorsAlan W. Lockstedt, Gary R. Portwood, Scott D. McDonough
Life of this patent
Estimating the term…
Abstract
A rolling cone drill bit is provided that has gage inserts on the first row from the bit axis to cut to full gage diameter that have a cutting portion enhanced with a layer of super abrasive material. The gage cutting surface has a center axis that is canted to be more normal to the gave curve such that its point of contact at gage is away from the thinner portion of the layer of super abrasive material.
Claims20
A drill bit, comprising:
- a bit body, comprising:
- a plurality of legs, each leg terminating in a journal shaft;
- at least one roller cone having a cone axis rotatably mounted on at least one of the journal shafts and having a plurality of rows of cutting inserts thereon including a gage row of cutting inserts;
- wherein the gage row includes at least one insert comprising a base portion defining an insert axis and a cutting portion having a generally convex cutting surface, wherein the at least one insert is inserted into a hole of the at least one roller cone such that the insert axis is not normal to the cone axis, wherein a cutting profile of the at least one insert at least partially overlaps a cutting profile of at least one insert on an adjacent row.
1 more element
A drill bit, comprising:
- a bit body;
- at least one roller cone having a cone axis rotatably mounted on the bit body and having a plurality of rows of cutting inserts thereon including a gage row of cutting inserts;
- wherein the gage row includes at least one insert comprising a base portion defining an insert axis and a cutting portion having a generally convex cutting surface, wherein the at least one insert is inserted into a hole of the at least one roller cone such that the insert axis is not perpendicular to a land of the cone surrounding the at least one insert and such that the insert axis is angled with respect to the cone axis.
Dependencies are inferred from the claim text.