Drill bit and method for producing a drill bit

Abstract

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 whilst 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 . Apparatus for use during orthopaedic surgery comprising:
 a metal shaft for initial longitudinal insertion through periosteum and other body material, such as cartilage and bone, followed by rotational movement to a further depth in the body material, said shaft comprising:
 (1) a pyramidal shaped end portion defining an insertion end point for creating a securing hole in the material to prevent the shaft from slipping on the periosteum as the shaft begins to rotate, said pyramidal shaped end portion having
 a. plurality of cutting edges disposed relative to one another to define the pyramidal shape of the end portion and to cut away bone material during rotation of said shaft; and 
 b. a plurality of faces defining said cutting edges; 
 
 (2) a shank portion; and 
 (3) a plurality of recesses for directing away debris produced during rotational movement of the shaft, each said recess having a first recess portion and a second recess portion: 
   said first recess portion extending at least partially into said shank portion for directing away debris produce during cutting as the shaft rotates; and   said second recess portion formed in said end portion, said second recess portion extending adjacent at least a portion of each of said cutting edges of said end portion; and   wherein the depth of the second recess portion of each said recess varies along a length thereof so that the cutting ability of the edge adjacent to the said end point is less than the cutting ability of the edge adjacent to the shaft.   
     
     
         2 . Apparatus as claimed in  1 , wherein said second recess portion defines the cutting ability of a said edge. 
     
     
         3 . Apparatus as claimed in  claim 1 , wherein said cutting edges meet to form the end point at the end of the pyramidal shaped end portion. 
     
     
         4 . Apparatus as claimed in  claim 1 , wherein said second portion of said each recess includes a V-shaped groove surface arranged to direct debris into said first recess. 
     
     
         5 . Apparatus as claimed in  claim 1  wherein said second portion of each said recess is non-helical. 
     
     
         6 . Apparatus as claimed in  claim 1 , wherein said faces extend between said plurality of edges, each of said faces being flat. 
     
     
         7 . Apparatus as claimed in  claim 1 , wherein said second portion of each said recess extends along a respective one of said faces.