Roof mining drill bit
View Patent ↗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 drilling apparatus, comprising;
the drill bit comprising a bit body intermediate a shank and a working surface;
the working surface comprising outer cutting elements with a carbide substrate bonded to a diamond working end with a pointed geometry, and the diamond working end comprising a 0.075 to 0.110 inch apex radius;
the outer cutting elements are pointed in opposing directions relative to another;
the outer cutting elements have an axis that forms an angle of 90 to 180 degrees with the axis of the bit body;
a central cutting element is positioned intermediate the opposing outer cutting elements and substantially coaxial with the bit body, the central cutting element also comprises the diamond working end comprising a 0.075 to 0.110 inch apex radius;
the central cutting element is configured to stabilize the drill bit as the outer cutting elements rotate about the central axis of the bit body;
wherein at an interface between the diamond and carbide substrate, the substrate comprises a tapered surface starting from a cylindrical rim of the substrate and ending at an elevated central region formed in the substrate.
2. The apparatus of claim 1 , wherein the central cutting element is slightly tilted in relation to the central axis of the bit body.
3. The apparatus of claim 1 , wherein the at least one of the cutting elements is placed within a dielectric material.
4. The apparatus of claim 3 , wherein a wire runs from the cutting element, through the dielectric material, and is in communication with a power source.
5. The apparatus of claim 1 , wherein metal in the diamond material of at least one cutting element causes the diamond to be electrically conductive enough to pick up a laterolog resistivity signal and the at least one cutting element is electrically isolated from the bit body.
6. The apparatus of claim 1 , wherein a canal is formed in the drill bit that runs along the central axis of the bit body and is configured to direct fluid into a formation.
7. The apparatus of claim 1 , wherein the axis of at least one outer cutting element is substantially parallel with another and another axis of another outer cutting element.
8. The apparatus of claim 1 , wherein at least one of the central cutting element and the outer cutting elements comprise slightly convex sides.
9. The apparatus of claim 1 , wherein at least one of the central cutting element and the outer cutting elements comprise a side formed by portions of different angles.
10. The apparatus of claim 9 , wherein the at least one of the portions is an upper portion that forms a 40 to 50 degree angle with the central axis.
11. The apparatus of claim 9 , wherein the at least one of the portions is an middle portion that forms a 33 to 40 degree angle with the central axis.
12. The apparatus of claim 9 , wherein the at least one of the portions is an lower portion that forms a 25 to 33 degree angle with the central axis.