04694918 is referenced by 251 patents and cites 11 patents.

A percussion rock bit comprises a steel body having means for connection to a drill string at one end and having a plurality of inserts at the other end for crushing rock at the bottom of a hole being drilled. The inserts have a cemented tungsten carbide body partially embedded in the steel bit and at least two layers at the protruding drilling portion of the insert. The outermost layer contains polycrystalline diamond. The remaining layers adjacent the polycrystalline diamond layer are transition layers containing a composite of diamond crystals and precemented tungsten carbide, the composite having a higher diamond crystal content adjacent the polycrystalline diamond layer and a higher precemented tungsten carbide content adjacent the tungsten carbide layer.

Another embodiment of rock bit has three cones with tungsten carbide inserts in the cutting structure of each cone. The gage row inserts have a layer of polycrystalline diamond on the converging portion protruding from the surface of the cone. One or more transition layers are provided between the tungsten carbide insert body and the polycrystalline diamond layer. Such a transition layer comprises diamond and precemented tungsten carbide.

Title
Rock bit with diamond tip inserts
Application Number
600399
Publication Number
4694918
Application Date
February 13, 1986
Publication Date
September 22, 1987
Inventor
David R Hall
Provo
UT, US
Agent
Christie Parker & Hale
Assignee
Smith International
CA, US
IPC
E21B 10/52
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