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 and the cutting end having 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, and 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 being 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 101 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 101 may be rotationally fixed to the drum 103 bringing the tools 101 into contact with the formation 104. A holder 102 or block is attached to the rotating drum 103, and the tool 101 is inserted into the holder 102. The holder 102 or block may hold the tool 101 at an angel offset from the direction of rotation, such that the tool 101 engages the pavement at a preferential angle. The tool 101 may be rotationally fixed to the rotating drum 103.

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

In the preferred embodiment, the carbide segment 203 may have a symmetric geometry about its central axis 208. The superhard material 200 may comprise a substantially conical surface 209 with a side 210 forming a 35 to 55 degree angle 211 with the central axis 208 of the carbide segment 203. The angle 211 formed between the side 210 and the central axis 208 of the carbide segment 203 is such that a portion 212 of the steel body 207 is protected from contacting the formation. It is beneficial to protect the steel body because of its tendency to wear more easily than the carbide portions of the tool. The carbide segment 203 may be brazed to the cemented carbide substrate 201 with a braze comprising a thickness of 1.0 to 10 microns. 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.

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

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

In the embodiment of FIG. 5, a portion 500 of the steel body 207 may protrude into a bore 501 formed in the carbide segment 203. The bore 501 formed in the carbide segment 203 may comprise a tapered geometry 502. The superhard material 200 may have a substantially pointed geometry with an apex 213 having a 0.050 to 0.125 inch radius 214 and a 1100 to 0.500 inch thickness 215 from the apex 213 to the non-planar interface 250.

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

FIG. 6 a shows an embodiment of a tool 101 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 101 to the holder 650. The pin may be adapted to expand the lining 655 so that the tool 101 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 the carbide segment 203 which may be open to a base end of the 751 of the bolster 203. The shaft 651 may be press into the bore 750 of the carbide segment.

FIG. 6 b is an orthogonal diagram of a tool with a carbide segment secured to the steel body 207.

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 in 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 superhard material bonded to a cemented metal carbide substrate at a non-planar interface; the cemented metal carbide substrate bonded to a front end of a cemented metal carbide segment; a carbide stem formed in a base end of the carbide segment opposite the front end; the carbide stem being press-fit into a bore of a steel body; wherein the steel body is rotationally fixed to a drum adapted to rotate about an axis.

2. The tool of claim 1, wherein the carbide segment comprises a symmetric geometry about its central axis.

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

4. The tool of claim 1, wherein at least one reentrant is formed at an interfacial surface intermediate the steel body and the carbide segment.

5. The tool of claim 1, wherein the bore of the steel body is tapered.

6. The tool of claim 1, wherein the superhard material comprises a substantially conical surface with a side forming a 35 to 55 degree angle with the central axis of the carbide segment.

7. The tool of claim 6, wherein the angle formed between the side and the central axis of the carbide segment is such that a portion of the steel body is protected from contacting the formation.

8. The tool of claim 1, wherein the superhard material has a substantially pointed geometry with an apex comprising a 0.050 to 0.125 inch radius.

9. The tool of claim 8, wherein the superhard material comprises a 0.100 to 0.500 inch thickness from the apex to the non-planar interface.

10. The tool of claim 8, wherein the substantially pointed geometry comprises a convex side.

11. The tool of claim 8, wherein the substantially pointed geometry comprises a concave side.

12. The tool of claim 1, wherein a portion of the steel body comprises hard facing.

13. The 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, silicon bonded diamond, or combinations thereof.

14. The tool of claim 1, wherein a portion of the steel body protrudes into a bore formed in the carbide segment.

15. The tool of claim 14, wherein the bore formed in the carbide segment comprises a tapered geometry.

16. The tool of claim 1, wherein a gap is formed intermediate a base of the stem of the carbide segment and a floor of the bore formed in the steel body.

17. The tool of claim 1, wherein the superhard material comprises a flat geometry.

18. A high impact resistant tool, comprising: a superhard material bonded to a cemented metal carbide substrate at a non-planar interface; the cemented metal carbide substrate bonded to a front end of a cemented metal carbide segment; a bore formed in a base end of the carbide segment opposite the front end; a steel shaft being press-fit into a bore of the carbide segment; wherein the steel shaft is rotationally fixed to a drum adapted to rotate about an axis.

19. The tool of claim 18, wherein the superhard material has a substantially pointed geometry with an apex comprising a 0.050 to 0.125 inch radius.

20. The tool of claim 18, wherein the superhard material comprises a 0.100 to 0.500 inch thickness from the apex to the non-planar interface.