An impact tool for use with a driving mechanism, the impact tool including an impact tip formed from a super hard material and having an apex and an attachment end, with the attachment end being bonded to a cemented metal carbide substrate at a non-planar interface. The cemented metal carbide substrate is bonded in turn to the front end of a cemented metal carbide bolster. The carbide bolster is securable against an outer surface of a driving mechanism through a press fit.
1. An impact tool, comprising;
an impact tip formed from a superhard material, the impact tip having an apex and an attachment end spaced apart from the apex;
a cemented metal carbide substrate having a first end and a second end spaced apart from the first end, the first end being bonded to the attachment end at a non-planar interface; and
a cemented metal carbide bolster having a front end, a base end spaced apart from the front end, and a substantially conical side wall increasing in diameter from the front end to the base end, the front end being bonded to the second end at a planar interface, and the base end having an opening to a cavity formed in the bolster, the opening being coaxial with a central axis of the tool.
2. The tool of claim 1 , wherein a diameter of the front end is less than half of a diameter of the base end.
3. The tool of claim 1 , wherein a base surface of the base end is substantially flat.
4. The tool of claim 1 , wherein a portion of the base end includes an inward taper generally decreasing towards the base end.
5. The tool of claim 1 , wherein a base surface of the base end is substantially convex or concave.
6. The tool of claim 1 , wherein a diameter of the opening is smaller than a diameter of a portion of the cavity.
7. The tool of claim 1 , wherein the carbide bolster comprises at least one flat disposed on its outer surface.
8. The tool of claim 1 , wherein the cavity comprises at least one threadform adapted to attach to a threaded shank.
9. The tool of claim 1 , wherein a portion of an inside surface of the cavity comprises an inward taper from the opening towards a closed end of the cavity.
10. The tool of claim 1 , wherein the impact tip includes a substantially conical surface having a side which forms an angle with a central axis of the impact tool between 35 and 55 degrees.
11. The tool of claim 1 , wherein a diameter of the substrate is less than a diameter of the opening.
12. The tool of claim 1 , wherein the apex comprises a radius of 0.50 to 0.125 inches.
13. The tool of claim 12 , wherein a thickness of the impact tip at the apex is greater than a third of the diameter of the planar interface between the substrate and the bolster.
14. The tool of claim 1 , wherein the cavity includes a closed end having a diameter greater than a diameter of the opening in the base end of the carbide bolster.
15. The tool of claim 13 , wherein the closed end of the cavity comprises a domed geometry.
16. An impact tool for use with a driving mechanism, said impact tool comprising:
a substrate formed from a cemented metal carbide material, said substrate having a first end and a second end spaced apart from said first end;
an impact tip formed from a super hard material, said impact tip having an apex and an attachment end spaced apart from said apex, said attachment end being bonded to said first end of said substrate at a non-planar interface; and
a bolster formed from a cemented metal carbide material, said bolster having a front end and a base end spaced from said front end, said front end being bonded to said second end of said substrate at a planar interface, said base end having an opening to a cavity formed within said bolster, said opening and said cavity being coaxial with a central axis of said impact tool.
17. The impact tool of claim 16 , wherein said cavity includes a closed end having a diameter greater than a diameter of said opening.
18. The impact tool of claim 17 , wherein a portion of an inside surface of said cavity comprises an inward taper towards a central axis of said impact tool in a direction towards said closed end of said cavity.
19. The impact tool of claim 16 , wherein a portion of an outside surface of said bolster proximate said base end comprises an inward taper towards a central axis of said impact tool in a direction towards said base end of said bolster.
20. An impact tool for use with a driving mechanism, said impact tool comprising:
a substrate formed from a cemented metal carbide material, said substrate having a first end and a second end spaced apart from said first end;
an impact tip formed from a super hard material, said impact tip having an apex and an attachment end spaced apart from said apex, said attachment end being bonded to said first end of said substrate at a non-planar interface; and
a bolster formed from a cemented metal carbide material, said bolster having a front end and a base end spaced from said front end, said bolster having a substantially conical side wall increasing in diameter from said front end to said base end, said front end being bonded to said second end of said substrate at a planar interface.