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US 4,694,918 AGranted
Rock bit with diamond tip inserts
AssigneeSmith International, Inc.
InventorDavid R. Hall
Life of this patent
Estimating the term…
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AssigneeSmith International, Inc.
InventorDavid R. Hall
Estimating the term…
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.
A percussion rock bit, comprising:
A percussion rock bit comprising a steel body including a plurality of inserts partially embedded in the steel body for crushing rock at the bottom of a hole being drilled, at least some of the inserts comprising a cemented tungsten carbide body, a polycrystalline diamond layer on the outermost end of the insert, and two transition layers between the polycrystalline diamond layer and the cemented tungsten carbide body comprising a composite material of diamond crystals, precemented tungsten carbide and cobalt, the transition layer adjacent the polycrystalline layer having a greater proportion of diamond crystals relative to precemented tungsten carbide than the transition layer adjacent the cemented tungsten carbide body.
An insert comprising a cylindrical cemented tungsten carbide body having a converging portion at one end, the converging portion having an outer layer comprising polycrystalline diamond and two transition layers comprising a composite of diamond crystals, precemented tungsten carbide and cobalt, the outer transition layer adjacent the polycrystalline diamond layer having a greater diamond crystal content than the inner transition layer adjacent the tungsten carbide body.
An insert partially embedded in a steel rock bit for crushing rock at the bottom of a hole being drilled, comprising a cylindrical body including two pieces of cemented tungsten carbide bonded together, an inner carbide piece being embedded in the steel rock bit body and comprising relatively softer tungsten carbide, and an outer carbide piece protruding from the rock bit body comprising relatively harder carbide, a layer including polycrystalline diamond on the protruding piece, and at least one transition layer between the polycrystalline diamond layer and the outer carbide piece, where the transition layer comprises a composite material of diamond crystals and precemented tungsten carbide.
A rock bit comprising:
An insert for a roller cone rock bit comprising:
Dependencies are inferred from the claim text.