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. At least one recess has 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. The second portion of the at least one recess extends along an edge of the drill tip.

1 . A drill bit comprising:
 a shaft which has a pyramidal shaped end defining a drill tip with a plurality of edges defining the pyramidal shape; and   one or more recesses for directing away debris produced whilst drilling, the or each recess having a first portion extending along the shaft and a second portion which extends along the drill tip, wherein the second portion of the or each recess extends along an edge of the drill tip.   
     
     
         2 . A drill bit as claimed in  claim 1 , wherein each edge defines a cutting edge and preferably the or each recess is located to further define the cutting edge. 
     
     
         3 . A drill bit as claimed in  claim 2 , wherein each edge extends from the shaft to a remote point of the drill tip. 
     
     
         4 . A drill bit as claimed in  claim 1 , wherein the depth of the second portion of each of the recesses varies along a length thereof relative to a surface of the drill tip so that the cutting ability of the edge adjacent to the point of the drill bit is less than the cutting ability of the edge adjacent to the shaft. 
     
     
         5 . A drill bit as claimed in  claim 1 , wherein the first portion of the or each recess is substantially helical in shape, whilst the second portion of the or each recess is substantially straight. 
     
     
         6 . A drill bit as claimed in  claim 1 , wherein the drill tip includes at least three edges which define the pyramidal shape of the drill tip. 
     
     
         7 . A drill bit as claimed in  claim 6 , wherein the at least three corresponding surfaces extend between the three edges, wherein prior to forming the or each recess the surfaces may be flat, planar or concave with respect to the drill bit. 
     
     
         8 . A drill bit as claimed in any  claim 7 , wherein the second portion of the or each recess extends along a respective one of the surfaces. 
     
     
         9 . A drill bit as claimed in  claim 1 , wherein at least one of the edges of the drill tip is bevelled so as to enhance the cutting ability of the cutting edge. 
     
     
         10 . A drill bit comprising:
 a shaft having a drilling end defining a drill point;   at least one face that extends to and helps define the drill point, the or each face generally subtending an acute angle with a longitudinal axis of the shaft; and   at least one flute defined in the shaft for directing away debris produced during drilling, with the at least one flute intersecting with the at least one face, such that, in end view, the flute is offset from a central part of the face.   
     
     
         11 . A bit as claimed in  claim 10  wherein the flute intersects the face in a manner that defines a continuous curve at the flute-face intersection. 
     
     
         12 . A bit as claimed in  claim 10  wherein the or each face: (a) is flat, being defined as a bevel; (b) is curved or v-shaped concavely into the shaft; and (c) has a chamfer or a v-shaped groove along one edge thereof. 
     
     
         13 . A bit as claimed in  claim 12  wherein in (c) the flute extends into the face adjacent to said one edge. 
     
     
         14 . A bit as claimed in  claim 13  wherein the flute intersects with the v-shaped groove. 
     
     
         15 . A bit as claimed in  claim 10 , wherein three faces are provided at the drilling end, each evenly offset with respect to the other two and each tapering down to the drill point to provide the drill end with the appearance of a triangular pyramid. 
     
     
         16 . A bit as claimed in  claim 15  wherein a respective flute is provided to intersect with each face. 
     
     
         17 . A bit as claimed in  claim 10  wherein four faces are provided at the drilling end, each evenly offset with respect to adjacent faces on either side thereof and each tapering down to the drill point to provide the drill end with the appearance of a square pyramid. 
     
     
         18 . A bit as claimed in  claim 17  wherein a respective flute is provided to intersect with each of only two of the faces, being opposing faces at the drill end. 
     
     
         19 . A bit as claimed in  claim 10 , wherein the or each flute extends generally spirally away from its respective face and at least part way along the shaft. 
     
     
         20 . A method for producing a drill bit, comprising the steps of:
 forming a shaft which has a pyramidal shaped end defining a drill tip with a plurality of edges defining the pyramidal shape; and   forming one or more recesses for directing away debris produced whilst drilling, the or each recess having a first portion extending along the shaft and a second portion which extends into the drill tip, wherein the second portion of the or each recess extends along an edge of the drill tip.   
     
     
         21 . The method as claimed in  claim 20 , wherein the step of forming the one or more recesses includes moving a grinding element outwardly from the drill tip as it moves therealong such that the depth of the second portion of each of the recesses varies along a length thereof relative to a surface of the drill tip. 
     
     
         22 . The method as claimed in  claim 20 , wherein the or each recess is formed adjacent to a respective edge such that the cutting ability of the edge adjacent to a point of the drill tip is less than the cutting ability of the edge adjacent to the shaft.