Roof Mining Drill Bit
In one aspect of the invention a rotary mine roof drilling apparatus has an arm attached to and intermediate a drill bit and a platform. The apparatus also has a thrusting mechanism adapted to push the drill bit into a mine roof. The drill bit has a bit body intermediate a shank and a working surface. The working surface has a cutting element with a carbide substrate bonded to a diamond working end with a pointed geometry; and the diamond working end has a 0.050-0.200 inch apex radius.
1 . A rotary mine roof drilling apparatus, comprising;
an arm attached to and intermediate a drill bit and a platform;
a thrusting mechanism adapted to push the drill bit into a mine roof or wall;
the drill bit comprising a bit body intermediate a shank and a working surface;
the working surface comprising a cutting element with a carbide substrate bonded to a diamond working end with a pointed geometry; and
the diamond working end comprising a 0.050-0.200 inch apex radius.
2 . The drilling apparatus of claim 1 , wherein the working surface comprises multiple cutting elements.
3 . The drilling apparatus of claim 1 , wherein the cutting element is substantially coaxial with the bit body.
4 . The drilling apparatus of claim 1 , wherein the cutting element is spring loaded.
5 . The drilling apparatus of claim 1 , wherein the cutting element is bi-centered relative to the bit body.
6 . The drilling apparatus of claim 3 , wherein the substantially coaxial cutting element comprises an axis adjacent the axis of the bit body.
7 . The drilling apparatus of claim 1 , wherein working surface comprises one stationary diamond and at least one cutting element that rotates around it.
8 . The drilling apparatus of claim 1 , wherein the arm telescopes.
9 . The drilling apparatus of claim 1 , wherein the pointed geometry comprises a thickness of at least 0.100 inch.
10 . The drilling apparatus of claim 1 , wherein the diamond working end is processed in a high temperature high pressure press.
11 . The drilling apparatus of claim 10 , wherein the diamond working end is cleaned in a vacuum and sealed in a can by melting a sealant disk within the can prior to processing in the high temperature high pressure press.
12 . The drilling apparatus of claim 1 , wherein the diamond working end comprises infiltrated diamond.
13 . The drilling apparatus of claim 1 , wherein the diamond working end comprises a metal catalyst concentration of less than 5 percent by volume.
14 . The drilling apparatus of claim 1 , wherein the diamond working end is bonded to the carbide substrate at an interface comprising a flat normal to the axis of the cutting element.
15 . The drilling apparatus of claim 1 , wherein a surface of the diamond working end is electrically insulating.
16 . The drilling apparatus of claim 1 , wherein the diamond working end comprises an average diamond grain size of 1 to 100 microns.
17 . The drilling apparatus of claim 1 , wherein the diamond working end comprises a characteristic of being capable of withstanding greater than 80 joules in a drop test with carbide targets.
18 . The drilling apparatus of claim 1 , wherein the diamond working end comprises a central axis that comprises a 35-55 degree angle relative to a side of the diamond.
19 . The drilling apparatus of claim 1 , wherein the shank comprises at least one connecting component.
20 . The drilling apparatus of claim 1 , wherein the bit body comprises a cutting element.