Shearing Cutter on a Degradation Drum
In one aspect of the present invention, a pick comprises a forward end and rearward end. The forward end comprises a shearing cutter and the rearward end comprises a shank. The shank and the shearing cutter are arranged co-axially about a central axis. The shearing cutter is supported by an enlarged section that narrows towards the shearing cutter and that has a greater cross section than the shank along a plane substantially perpendicular to the central axis. The shearing cutter comprises a flat surface that is substantially perpendicular to the central axis.
1 . A pick, comprising:
a forward end and rearward end;
the forward end comprising a shearing cutter and the rearward end comprising a shank;
the shank and the shearing cutter are arranged co-axially about a central axis;
the shearing cutter is supported by an enlarged section that narrows towards the shearing cutter and that has a greater cross section than the shank along a plane substantially perpendicular to the central axis; and
the shearing cutter comprising a flat surface that is substantially perpendicular to the central axis.
2 . The pick of claim 1 , wherein the pick is secured within a holder attached to a drum.
3 . The pick of claim 1 , wherein the shank is rotatably secured within a bore and is rotatable about a central axis of the shank.
4 . The pick of claim 1 , wherein the forward end is tapered towards the shearing cutter.
5 . The pick of claim 1 , wherein the shearing cutter comprises cemented metal carbide.
6 . The pick of claim 1 , wherein the shearing cutter comprises a super hard material bonded to cemented metal carbide at a non-planar interface, the super hard material forming the flat surface.
7 . The pick of claim 6 , wherein the super hard material comprises an axial thickness greater than the thickness of the cemented metal carbide.
8 . The pick of claim 1 , wherein the shank is press fit into the bore of the holder.
9 . The pick of claim 1 , wherein the shearing cutter is brazed to a carbide bolster that progressively increases in diameter from the forward end.
10 . The pick of claim 1 , wherein the shearing cutter is bonded to a carbide bolster attached to a rotating shield.
11 . The pick of claim 1 , wherein the pick is incorporated in a milling machine.
12 . The pick of claim 1 , wherein the pick is incorporated in mining machine.
13 . The pick of claim 1 , wherein the shearing cutter comprises a flat edge, rounded edge, chamfered edge, double chamfered edge, or combinations thereof.
14 . The pick of claim 1 , wherein the pick is incorporated in a trenching machine.
15 . The pick of claim 1 , wherein the pick comprises a negative rake angle of 15 degrees approximately.
16 . A degradation drum, comprising:
a pick secured to an outer surface of the drum through a block rigidly mounted to the outer surface;
the block comprising a bore with an inner surface, the shank being secured within the bore;
at least one pick comprising a shearing cutter comprising a shearing cutter comprising a flat surface;
the shearing cutter and the shank are co-axially arranged about a central axis; and
the flat surface of the shearing cutter is substantially perpendicular to the central axis.
17 . The drum of claim 16 , wherein the at least one shearing cutter is positioned proximate a longitudinal edge of the drum.
18 . The drum of claim 16 , wherein the bore is substantially aligned with a length of the block and is substantially coaxial with the central axis of the pick.
19 . The pick of claim 16 , wherein the pick is laterally offset from the direction of rotation of the drum.
20 . The pick of claim 16 , wherein the pick is offset at an angle of 7 to 15 degrees.