Drill Bit and Cutter Element Having Chisel Crest With Protruding Pilot Portion
AssigneeSmith International, Inc.
InventorsScott D. McDonough, Amardeep Singh
Life of this patent
Estimating the term…
Abstract
A rolling cone drill bit includes a cutter element having a cutting portion with a chisel crest and a pilot portion extending beyond the chisel crest. The pilot portion includes a cutting surface that may be generally conical, or form a second chisel crest. The cutting tip of the pilot portion is supported by buttress portions which emerge from and extend beyond the flanks of the chisel crest to provide additional strength and support for the material of the pilot portion that extends beyond the height of the chisel crest.
Claims45
A cutter element for a drill bit comprising:
- a base portion;
- a cutting portion extending from said base portion and comprising a cutting surface having a chisel crest with flanking surfaces meeting in an elongate and a peaked ridge defining a crest height, said cutting portion further comprising a pilot portion intersecting said chisel crest and extending above said crest height.
A cutter element for mounting in a rolling cone drill bit, comprising:
- a base portion and a cutting portion extending from said base portion;
- wherein said cutting portion includes a plurality of chisel crest segments extending away from said base portion to a crest segment height, and a pilot portion separating said chisel crest segments and extending to a height above the crest segment height of each of said chisel crest segments.
A cutting insert for insertion in a rolling cone drill bit, comprising:
- a base portion;
- a cutting portion extending from said base portion to a distance defining an insert height, said cutting portion comprising a pilot portion extending to said insert height and defining a pilot end profile when viewed from a first direction;
- said cutting portion further comprising a first chisel crest extending from said base to a crest height that is less than said insert height;
- said first chisel crest including a pair of flanking surfaces and defining a crest end profile when viewed from said first direction;
- wherein said pilot end profile extends laterally beyond said crest end profile when viewed from said first direction.
A drill bit for cutting a borehole having a borehole sidewall, corner and bottom, the drill bit comprising:
- a bit body including a bit axis;
- a rolling cone cutter mounted on said bit body and adapted for rotation about a cone axis;
- a first plurality of cutter elements having a base portion secured in said rolling cone cutter and having a cutting portion extending therefrom;
- said cutting portion comprising a first chisel crest with flanking surfaces tapering to form an elongate and peaked ridge defining a crest height, and further comprising a pilot portion intersecting said first chisel crest and extending beyond said crest height.
Dependencies are inferred from the claim text.