EP0235455A2
Expired / Lapsed
EP
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Percussion rock bit
Assignee: Smith International Inc
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Filing: 1986-12-10
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Granted: —
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Expires: 2006-12-10
Abstract
Abstract A percussion rock bit comprises a steel body (10) having a pin (12) for connection to a drill string at one end and having a plurality of inserts (16) at the other end for crushing rock at the bottom of a hole being drilled. The inserts (16) have a cemented tungsten carbide body (20) partially embedded in the steel bit and at least two layers at the protruding drilling portion of the insert. The outermost layer (26) contains polycrystalline diamond. The remaining layers adjacent the polycrystalline diamond layer (26) are transition layers (28,30) containing a composite of diamond crystals and precemented tungsten carbide, the composite having a higher diamond crystal content adjacent the polycrystalline diamond layer (26) and a higher precemented tungsten carbide content adjacent the tungsten carbide body (20).
Inventors
- 👤 David Richard Hall
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 19:11
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/46; E21B10/56; E21B10/567; E21B10/5673; B; B22; B22F; B22F7/00; B22F7/06; B32; B32B; B32B15/00; B32B15/01; B01; B01J; B01J2203/00; B01J2203/06; B01J2203/0675; B01J2203/0685; B22F5/00; B22F2005/001; B22F2998/00
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
133 words
A percussion rock bit, comprising: a steel body; means at one end of the steel body for connecting the bit to a drill string; a plurality of inserts embedded in the other end of the steel body, at least a portion of the inserts comprising: a cemented tungsten carbide body having a grip portion embedded in the steel body and a converging end portion protruding from the surface of the steel body; a polycrystalline diamond layer on the converging end of the carbide body; at least one transition layer between the polycrystalline diamond layer and the carbide body, such a transition layer comprising a composite containing diamond crystals and precemented tungsten carbide particles, wherein the diamond crystal content is greater adjacent the polycrystalline diamond layer and lower adjacent the cemented tungsten carbide body.
Claim 2
Dependent Claim
133 words
A percussion rock bit, comprising: a steel body; means at one end of the steel body for connecting the bit to a drill string; a plurality of inserts embedded in the other end of the steel body, at least a portion of the inserts comprising: a cemented tungsten carbide body having a grip portion embedded in the steel body and a converging end portion protruding from the surface of the steel body; a polycrystalline diamond layer on the converging end of the carbide body; at least one transition layer between the polycrystalline diamond layer and the carbide body, such a transition layer comprising a composite containing diamond crystals and precemented tungsten carbide particles, wherein the diamond crystal content is greater adjacent the polycrystalline diamond layer and lower adjacent the cemented tungsten carbide body.
Claim 3
Dependent Claim
24 words
A rock bit as claimed in Claim 1, wherein the polycrystalline diamond layer includes from about one to about ten percent by volume cobalt.
Claim 4
Dependent Claim
26 words
A rock bit as claimed in Claim 1 or in Claim 2, comprising two transition layers between the polycrystalline diamond layer and the tungsten carbide body.
Claim 5
Dependent Claim
40 words
A percussion rock bit as claimed in Claim 3 wherein the transition layer adjacent the polycrystalline diamond layer has a greater proportion of diamond crystals relative to precemented tungsten carbide than the transition layer adjacent the cemented tungsten carbide body.
Claim 6
Dependent Claim
38 words
A rock bit as claimed in Claim 3 or in Claim 4, wherein the transition layer adjacent the polycrystalline diamond layer comprises about 75 percent by volume diamond crystals and about 25 percent by volume precemented tungsten carbide.
Claim 7
Dependent Claim
40 words
A rock bit according to any one of Claims 3 to 5 wherein the transition layer adjacent the cemented tungsten carbide body comprises about 50 percent by volume diamond crystals and about 50 percent by volume precemented tungsten carbide particles.
Claim 8
Dependent Claim
38 words
A rock bit according to any one of Claims 1 to 3 wherein the transition layer adjacent the polycrystalline diamond layer comprises about 60 percent by volume diamond crystals and about 40 percent by volume precemented tungsten carbide.
Claim 9
Dependent Claim
40 words
A rock bit according to any one of Claims 1 to 3 and 7, wherein the transition layer adjacent the tungsten carbide body comprises about 40 percent by volume diamond crystals and about 60 percent by volume precemented tungsten carbide.
Claim 10
Dependent Claim
27 words
A rock bit according to any one of Claims 5 to 8 wherein the diamond crystals include from about one to about ten percent by volume cobalt.
Claim 11
Dependent Claim
55 words
An insert for a rock bit, the insert comprising a polycrystalline diamond layer, a tungsten carbide body and two transition layers separating the polycrystalline diamond layer from the tungsten carbide body, the transition layer adjacent the polycrystalline diamond layer having a greater diamond crystal content than the inner transition layer adjacent the tungsten carbide body.
Claim 12
Dependent Claim
55 words
An insert for a rock bit, the insert comprising a polycrystalline diamond layer, a tungsten carbide body and two transition layers separating the polycrystalline diamond layer from the tungsten carbide body, the transition layer adjacent the polycrystalline diamond layer having a greater diamond crystal content than the inner transition layer adjacent the tungsten carbide body.
Claim 13
Dependent Claim
30 words
An insert according to Claim 10, wherein the transition layer adjacent the polycrystalline diamond layer comprises about 75 percent diamond crystals and about 25 percent by volume precemented tungsten carbide.
Claim 14
Dependent Claim
38 words
An insert according to Claim 10 or to Claim 11 wherein the transition layer adjacent the cemented tungsten carbide body comprises about fifty percent by volume diamond crystals and about fifty percent by volume precemented tungsten carbide particles.
Claim 15
Dependent Claim
32 words
An insert according to Claim 10, wherein the transition layer adjacent the polycrystalline diamond layer comprises about 60 percent by volume diamond crystals and about 40 percent by volume precemented tungsten carbide.
Claim 16
Dependent Claim
38 words
An insert according to any one of Claims 10, 11 or 13, wherein the transition layer adjacent the tungsten carbide body comprises about 40 percent by volume diamond crystals and about 60 percent by volume precemented tungsten carbide.
Claim 17
Dependent Claim
26 words
An insert according to any one of Claims 10 to 14, wherein the diamond crystals include from about one to about ten percent by volume cobalt.
Claim 18
Dependent Claim
59 words
An insert for a rock bit comprising a cylindrical body including two pieces of cemented tungsten carbide bonded together, an inner carbide piece being embedded in the rock bit and comprising relatively harder tungsten carbide, and an outer carbide piece protruding from the rock bit comprising relatively softer carbide, and a layer including polycrystalline diamond on the protruding piece.
Claim 19
Dependent Claim
59 words
An insert for a rock bit comprising a cylindrical body including two pieces of cemented tungsten carbide bonded together, an inner carbide piece being embedded in the rock bit and comprising relatively harder tungsten carbide, and an outer carbide piece protruding from the rock bit comprising relatively softer carbide, and a layer including polycrystalline diamond on the protruding piece.
Claim 20
Dependent Claim
38 words
An insert according to Claim 16, further comprising at least one transition layer between the polycrystalline diamond layer and the outer carbide piece, wherein the transition layer comprises a composite material of diamond crystals and precemented tungsten carbide.
References Cited (Backward Citations)
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