Non-rotating pick with a pressed in carbide segment

Abstract

In one aspect of the present invention, a high impact resistant tool has a superhard material bonded to a cemented metal carbide substrate at a non-planar interface. The cemented metal carbide substrate is bonded to a front end of a cemented metal carbide segment. A stem formed in the base end of the carbide segment opposite the front end is press fit into a bore of a steel body. The steel body is rotationally fixed to a drum adapted to rotate about its axis.

Description

BACKGROUND OF THE INVENTION

Formation degradation, such as asphalt milling, mining, or excavating, may result in wear on attack tools. Consequently, many efforts have been made to extend the life of these tools in a cost-effective manner.

U.S. Pat. No. 6,102,486 to Briese, which is herein incorporated by reference for all that it contains, discloses a frustum cutting insert having a cutting end and a shank end. The cutting end has a cutting edge and inner walls defining a conical tapered surface. First walls in the insert define a cavity at the inner end of the inner walls and second walls define a plurality of apertures extending from the cavity to regions external the cutting insert to define a powder flow passage from regions adjacent the cutting edge, past the inner walls, through the cavity and through the apertures.

U.S. Pat. No. 4,944,559 to Sionnet et al., which is herein incorporated by reference for all that it contains, discloses a body of a tool consisting of a single-piece steel component. The housing for the composite abrasive component is provided in this steel component. The working surface of the body has, at least in its component-holder part, an angle at the lower vertex of at least 20% with respect to the angle at the vertex of the corresponding part of a metallic carbide tool for working the same rock. The surface of the component holder is at least partially covered by an erosion layer of hard material.

U.S. Pat. No. 5,235,961 to McShannon, which is herein incorporated by reference for all that it contains, discloses a carbide mineral cutting tip with a solid carbide body having at least one front face, at least one top face, a bottom seating face, a rear face, and side faces. The rear face is provided at the end of an extended tail portion of the tip, whereby the front-to-rear length of the tip approximates to twice the depth of the tip represented by the top-to-bottom length of the front face. The invention also includes a mineral cutter pick provided with such a tip.

BRIEF SUMMARY OF THE INVENTION

In one aspect of the present invention, a high impact resistant tool has a superhard material bonded to a cemented metal carbide substrate at a non-planar interface. The cemented metal carbide substrate is bonded to a front end of a cemented metal carbide segment. A stem formed in the base end of the carbide segment opposite the front end is press fit into a bore of a steel body. The bore of the steel body may be tapered. The steel body is rotationally fixed to a drum adapted to rotate about an axis.

In some embodiments, the carbide segment may have a symmetric geometry about its central axis, whereas in other embodiments the carbide segment may comprise an asymmetric geometry. At least one reentrant may be formed at an interfacial surface intermediate the steel body and the carbide segment. The superhard material may comprise a substantially conical surface with a side forming a 35 to 55 degree angle with a central axis of the tool. The angle formed between the side and the central axis of the tool is such that a portion of the steel body is protected from contacting the formation. The superhard material may have a substantially pointed geometry with an apex comprising 0.050 to 0.125 inch radius and a 0.100 to 0.500 inch thickness from the apex to the non-planar interface. The substantially pointed geometry may have a convex or a concave side. The superhard material may comprise polycrystalline diamond, vapor-deposited diamond, natural diamond, cubic boron nitride, infiltrated diamond, layered diamond, diamond impregnated carbide, diamond impregnated matrix, silicon bonded diamond, or combinations thereof. The superhard material may be brazed to the cemented metal carbide substrate with a braze having a thickness of 1.0 to 10 microns.

A portion of the steel body may comprise hard facing. A portion of the steel may protrude into a bore formed in the carbide segment; the bore having a tapered geometry. A gap may be formed intermediate a base of the stem of the carbide segment and a floor of the bore formed in the steel body.

In another aspect of the present invention a high impact resistant tool has a superhard material bonded to a cemented metal carbide substrate at a non-planar interface. The cemented metal carbide substrate is bonded to a front end of a cemented metal carbide segment and a bore is formed in a base end of the carbide segment opposite the front end. A steel shaft is press-fit into a bore of the carbide segment and the steel shaft is rotationally fixed to a drum adapted to rotate about an axis.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional diagram of an embodiment of a plurality of tools on a rotating drum attached to a motor vehicle.

FIG. 2 is a cross-sectional diagram of an embodiment of a tool.

FIG. 3 is a cross-sectional diagram of another embodiment of a tool.

FIG. 4 is a cross-sectional diagram of another embodiment of a tool.

FIG. 5 is a cross-sectional diagram of another embodiment of a tool.

FIG. 6 is a cross-sectional diagram of another embodiment of a tool.

FIG. 6 a is a cross-sectional diagram of an embodiment of a tool fixed in a holder.

FIG. 6 b is an orthogonal diagram of another embodiment of a tool

FIG. 7 is an orthogonal diagram of an embodiment of a coal trencher.

DETAILED DESCRIPTION OF THE INVENTION AND THE PREFERRED EMBODIMENT

FIG. 1 is a cross-sectional diagram of an embodiment of a plurality of tools 101a attached to a rotating drum 103 connected to the underside of a pavement recycling machine 100. The recycling machine 100 may be a cold planer used to degrade man-made formations 104 such as pavement. Tools 101a may be rotationally fixed to the drum 103 bringing the tools 101a into contact with the formation 104. A holder 102 or block is attached to the rotating drum 103, and the tool 101a is inserted into the holder 102. The holder 102 or block may hold the tool 101a at an angel offset from the direction of rotation, such that the tool 101a engages the pavement at a preferential angle. The tool 101a may be rotationally fixed to the rotating drum 103.

FIG. 2 illustrates a tool 101b having a superhard material 200a bonded to a cemented metal carbide substrate 201 at a non-planar interface 250a. The cemented metal carbide substrate 201 is bonded to a front end 202 of a cemented metal carbide segment 203a. A carbide stem 204a is formed in a base end 205 of the cemented metal carbide segment 203a opposite the front end 202. The carbide stem 204a is press-fit into a bore 206a of a steel body 207a. The steel body 207a may be rotationally fixed to a rotating drum, such as the rotating drum 103 in FIG. 1. In some embodiments, the tool 101b may be indexable such that wear is reduced on the superhard material 200a.

In a preferred embodiment, the cemented metal carbide segment 203a may have a symmetric geometry about its central axis 208a. The superhard material 200a may comprise a substantially conical surface 209 with a side 210 forming an angle 211 of 35 to 55 degrees with the central axis 208a of the cemented metal carbide segment 203a. The angle 211 formed between the side 210 and the central axis 208a of the cemented metal carbide segment 203a is such that a portion 212 of the steel body 207a is protected from contacting a formation, such as formation 104 in FIG. 1. It is beneficial to protect the steel body 207a because of its tendency to wear more easily than the carbide portions of the tool 101b. The cemented metal carbide segment 203a may be brazed to the cemented carbide substrate 201 with a braze comprising a thickness of 1.0 to 10 microns. The superhard material 200a may comprise polycrystalline diamond, vapor-deposited diamond, natural diamond, cubic boron nitride, infiltrated diamond, layered diamond, diamond impregnated carbide, diamond impregnated matrix, silicon bonded diamond, or combinations thereof.

Referring now to FIG. 3, a tool 101c may have a superhard material 200b comprising a flat geometry 300. A cemented metal carbide segment 203b may have an asymmetric geometry about its central axis 208a. It may be beneficial that the cemented metal carbide segment 203b has an asymmetric geometry so that a portion of a steel body 207b may take some of the stresses exerted on the cemented metal carbide segment 203b during operation. In this embodiment, a gap 301 may be formed between a base 302 of a stem 204b of the cemented metal carbide segment 203b and a floor 303 of a bore 206b formed in the steel body 207b. The bore 206b of the steel body 207b may be tapered.

FIG. 4 shows an embodiment of a tool 101d comprising at least one reentrant 400 formed at an interfacial surface 401 between a steel body 207c and a cemented metal carbide segment 203c. In some embodiments, a portion of the steel body 207c may comprise hard facing 402 so that the portion of the steel body 207c may have a longer wear life. In this embodiment, the substantially pointed geometry of the superhard material 200c may comprise a concave side 403. In some embodiment of the present invention, carbide pieces may be bonded to the steel body 207c in place of or with the hard facing 402. In some embodiments, the carbide pieces may tile portions of the steel body 207c.

In the embodiment of FIG. 5, an embodiment of a tool 101e includes a portion 500 of a steel body 207d that may protrude into a bore 501 formed in a cemented metal carbide segment 203d. The bore 501 formed in the cemented metal carbide segment 203d may comprise a tapered geometry 502. A superhard material 200d may have a substantially pointed geometry with an apex 213 having a radius of curvature 214 of 0.050 to 0.125 inches and a thickness 215 of 0.100 to 0.500 inches from the apex 213 to a non-planar interface 250d.

FIG. 6 is an embodiment of a tool 101f wherein a steel body 207e comprises a first portion 600 and a second portion 601 of the steel body 207e protruding into a first bore 602 and a second bore 603, respectively, formed in a cemented metal carbide segment 203e. The substantially pointed geometry of a superhard material 200e may comprise a convex side 604.

FIG. 6 a shows an embodiment of a tool 101g rotationally fixed within a holder 650. A shaft 651 may be inserted into a bore 652 of the holder 650 and a hole 670 may be formed between an outer diameter 653 of the shaft 651 and an inner wall 654 of the bore 652. In some embodiments, the hole 670 may comprise a lining 655. The hole 670 may be adapted to receive a pin, the pin being adapted to rotationally fix the tool 101g to the holder 650. The pin may be adapted to expand the lining 655 so that the tool 101g may be more tightly held within the holder 650. The holder 650 may be attached to a drum. In other embodiments, the hole 670 adapted to receive the pin may be disposed through a center or a near-center portion of the shaft 651. A bore 750 may be formed in a cemented metal carbide segment 203f which may be open to a base end 751 of the cemented metal carbide segment 203f. The shaft 651 may be pressed into the bore 750 of the carbide segment.

FIG. 6 b is an orthogonal diagram of a tool 101h with a cemented metal carbide segment 203g secured to a steel body 207g.

FIG. 7 is an orthogonal diagram of an embodiment of a mining machine 700. A plurality of tools 101 are connected to a rotating drum 701 that is degrading coal 702. The rotating drum 701 is connected to an arm 703 that moves the drum 701 vertically in order to engage the formation 702. The arm 703 may move by means of a hydraulic arm 704. It may also pivot about an axis or a combination thereof. The mining machine 700 may move about by tracks, wheels, or a combination thereof. The mining machine 700 may also move about in a subterranean formation. The mining machine 700 may be in a rectangular shape providing for ease of mobility about the formation.

Other applications that involve intense wear of machinery may also be benefited by incorporation of the present invention. Milling machines such as cone crushers, jaw crushers, hammer mills, shaft impactors and the like, for example, may experience wear as they are used to reduce the size of material such as rocks, grain, trash, natural resources, chalk, wood, tires, metal, cars, tables, couches, coal, minerals, chemicals, or other natural resources. In other embodiments, the present invention may be used in chain driven trenchers, wheel trenchers, augers, and combinations thereof.

Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications apart from those shown or suggested herein, may be made within the scope and spirit of the present invention.

Claims

1. A high impact resistant tool, comprising: a cemented metal carbide substrate having a non-planar interface;a superhard material bonded to said cemented metal carbide substrate at said non-planar interface;a cemented metal carbide segment, said cemented metal carbide segment having a front end and a base end spaced apart from said front end, said cemented metal carbide substrate being bonded to said cemented metal carbide segment at said front end;a carbide stem formed in said base end of the cemented metal carbide segment; and,a steel body having an interfacial surface with a bore disposed therein, said bore being sized and shaped to receive said carbide stem in a press fit, said interfacial surface having a reentrant formed thereon.

2. The high impact resistant tool of claim 1, wherein the cemented metal carbide segment comprises a central axis about which the cemented metal carbide segment includes a symmetric geometry.

3. The high impact resistant tool of claim 1, wherein the carbide segment comprises an asymmetric geometry about its central axis.

4. The high impact resistant tool of claim 1, wherein the bore of the steel body is tapered.

5. The high impact resistant tool of claim 2, wherein the superhard material comprises a substantially conical surface with a side forming an angle of 35 to 55 degrees with the central axis.

6. The high impact resistant tool of claim 5, wherein the angle is such that a portion of the steel body is protected from contacting a formation being degraded by the tool.

7. The high impact resistant tool of claim 1, wherein the superhard material has a substantially pointed geometry with an apex comprising a radius of curvature of 0.050 to 0.125 inches.

8. The high impact resistant tool of claim 7, wherein the superhard material comprises a thickness of 0.100 to 0.500 inches from the apex to the non-planar interface.

9. The high impact resistant tool of claim 7, wherein the substantially pointed geometry comprises a convex side.

10. The high impact resistant tool of claim 7, wherein the substantially pointed geometry comprises a concave side.

11. The high impact resistant tool of claim 1, wherein a portion of the steel body comprises hard facing.

12. The high impact resistant tool of claim 1, wherein the superhard material comprises polycrystalline diamond, vapor-deposited diamond, natural diamond, cubic boron nitride, infiltrated diamond, layered diamond, diamond impregnated carbide, diamond impregnated matrix, and silicon bonded diamond.

13. The high impact resistant tool of claim 1, wherein a gap is formed between a base of the stem of the cemented metal carbide segment and a floor of the bore of the steel body.

14. The high impact resistant tool of claim 2, wherein the superhard material comprises a flat geometry.

15. A high impact resistant tool, comprising: a superhard material;a cemented metal carbide substrate, said superhard material being bonded to said cemented metal carbide substrate;a cemented metal carbide segment, said cemented metal carbide segment including: a front end, said cemented metal carbide substrate being bonded to said front end;a base end opposite said front end;a stem formed in said base end; and,a steel body, said steel body having a substantially flat interfacial surface between said steel body and said cemented metal carbide segment, said interfacial surface having reentrant and a bore formed therein, said bore being sized and shaped to receive said stem in a press fit.

16. The high impact resistant tool of claim 15, wherein the superhard material has a substantially pointed geometry with an apex comprising a radius of curvature of 0.050 to 0.125 inches.

17. The high impact resistant tool of claim 15, wherein the superhard material comprises a substantially conical surface with a side forming an angle of 35to 55 degrees with the central axis.