Drill bit and method for producing a drill bit
A drill bit including a shaft which has a pyramidal shaped end defining a drill tip with a plurality of edges defining the pyramidal shape. One or more recesses are provided for directing away debris produced while drilling, the at least one recess having a first portion extending along the shaft and a second portion having a first portion extending along the shaft and a second portion which extends along the drill tip; wherein the. The second portion which extends along the drill tip. The second portion of the at least one recess extends along an edge of the drill tip.
1. An orthopedic drill bit comprising:
a cylindrical shaft and a drill tip, said drill tip comprising:
a pyramidal shaped end having a plurality of cutting edges, said pyramidal shaped end having
(a) a distal portion comprising a plurality of faces defining said cutting edges, said faces meeting at a common point and defining a drill end point located on the longitudinal axis of said shaft; and
(b) a proximal portion having said cutting edges extending therealong;
a plurality of recesses for directing away debris produced while drilling, each said recess having two portions:
(1) a first recess portion extending along said shaft, said first recess portion extending adjacent said proximal portion and intersecting one of said cutting edges of said plurality of cutting edges to terminate said one of said cutting edges at a point spaced within the outer periphery of said shaft, said first recess portion providing a leading edge disposed at a negative cutting angle to the cutting surface at said outer periphery; and
(2) a second recess portion formed in said proximal portion of said pyramidal shaped end, said second recess portion extending toward another cutting edge of said plurality of cutting edges of said pyramidal shaped end.
2. An orthopedic drill bit as claimed in claim 1 , wherein the depth of the second recess portion of each said recess varies along a length thereof relative to a surface of the drill tip so that the cutting ability of the portion of said cutting edge adjacent to the point of the drill bit is less than the cutting ability of the portion of said cutting edge adjacent to the shaft.
3. An orthopedic drill bit as claimed in claim 1 , wherein the first recess portion is substantially helical in shape.
4. An orthopedic drill bit as claimed in claim 1 wherein said second recess portion is substantially non-helical.
5. An orthopedic drill bit as claimed in claim 1 , wherein said faces define the pyramidal shape of the drill tip.
6. An orthopedic drill bit as claimed in claim 5 , wherein said plurality of faces is three faces extending between three edges, each of said faces being flat.
7. An orthopedic drill bit as claimed in claim 5 , wherein said second recess portion of each said recess extends within said proximal portion.
8. An orthopedic drill bit as claimed in claim 1 , wherein said pyramidal shaped end is a tetrahedron pyramidal.
9. An orthopedic drill bit as claimed in claim 8 wherein the tetrahedron pyramidal shaped end has a square pyramid base.
10. An orthopedic drill bit as claimed in claim 8 where the tetrahedron pyramidal shaped end has a pentagonal pyramid base.