Resilient pick shank
In one aspect of the invention, a pick assembly comprises a pick shank press fitted within a bore of a pick holder. The pick comprises a pick head opposite the shank. The shank also comprises at least one longitudinal slot extending towards the pick head along the shank from a distal end of the shank. The slot allows the shank to resiliently collapse upon insertion into the bore while still allowing the shank to maintain a press fit while within the bore.
1. A pick assembly, the pick assembly comprising:
a shank having a longitudinal axis, a first end having a first surface, a second end spaced apart from said first surface and adapted for insertion into a retaining block, and a bore extending from said first surface to said second end;
a bolster having a rearward end and a forward end spaced apart from said rearward end, said rearward end having a second surface with a cavity formed therein, said second surface and said first surface together forming a conical taper interface with at least one void, said first surface being bonded to said second surface;
a tip formed of diamond enhanced material, said tip bonded to said bolster at said forward end.
2. The pick assembly of claim 1 , wherein said interface has a center proximate said longitudinal axis and said void is located at said center, wherein a first portion of said void is formed in said shank and a second portion of said void is formed in said bolster.
3. The pick assembly of claim 1 , wherein said void is an annular groove formed in said first surface of said shank.
4. The pick assembly of claim 1 , wherein said void is an annular groove formed in said second surface of the carbide bolster.
5. The pick assembly of claim 1 , wherein said interface has at least one protrusion configured to control a thickness of a braze material disposed therein.
6. The pick assembly of claim 1 , further comprising a bonding material disposed between said first and second surface, said bonding material having a variable thickness, wherein said variable thickness is greater at a periphery of the interface than near said center.
7. The pick assembly of claim 1 , further comprising a bonding material disposed between said first surface and said second surface, said bonding material comprising about 30 percent by weight to 60 percent by weight palladium.
8. The pick assembly of claim 1 , wherein a first void is formed at said center and an annular groove is formed in said first surface or said second surface.