Rotatable Cutting Tool

Abstract

A rotatable cutting tool with a shank for locating the rotatable cutting tool on a work face, a body and a hard tip wherein said body is of a generally tapered shape and has at least one flight wherein said at least one flight extends longitudinally and at least partially around the body whereby movement of the rotatable cutting tool through a substrate urges the tool to rotate.

1 . A rotatable cutting tool comprising a shank for locating the rotatable cutting tool on a work face, a body and a hard tip wherein said body is of a generally tapered shape and comprises at least one flight wherein said at least one flight extends longitudinally and at least partially around the body whereby movement of the rotatable cutting tool through a substrate urges the tool to rotate.  
   
   
       2 . The rotatable cutting tool according to  claim 1  wherein the at least one flight increase in dimension as the at least one flight extend away from the tip of the rotatable cutting tool.  
   
   
       3 . The rotatable cutting tool according to  claim 1  wherein the oblique surface provided to the direction of travel of the rotatable cutting tool increases in size as the flight or flights extend away from the tip.  
   
   
       4 . The rotatable cutting tool according to  claim 1  wherein a shank extends from the rear of the body and is of a generally cylindrical form whereby it is rotatable when inserted into a bore.  
   
   
       5 . The rotatable cutting tool according to  claim 1  wherein the shank includes a locating means for locating the rotatable cutting tool at a desired depth within the bore.  
   
   
       6 . The rotatable cutting tool according to  claim 1  wherein the generally tapered form of the body is a continuous taper whereby the increase in cross-sectional dimension of the body is constant from the tip of the shank.  
   
   
       7 . The rotatable cutting tool according to  claim 1  wherein the taper is a variable taper whereby the increase in cross-sectional dimension of the body varies from the tip to the shank.  
   
   
       8 . The rotatable cutting tool according to  claim 7  wherein the taper is a stepped taper that includes stepped increases in cross-sectional area from the tip to the taper.  
   
   
       9 . The rotatable cutting tool according to  claim 1  wherein the body has a circular cross-section extending along its length.  
   
   
       10 . The rotatable cutting tool according to  claim 1  wherein the body has a polygonal cross-section extending along its length.  
   
   
       11 . The rotatable cutting tool according to  claim 1  wherein the body has a cross-section that includes both circular and polygonal sections.  
   
   
       12 . The rotatable cutting tool according to  claim 1  wherein the tip of the rotatable cutting tool is multifaceted.  
   
   
       13 . The rotatable cutting tool according to  claim 12  wherein the tip is a square pyramid or a triangle pyramid.  
   
   
       14 . The rotatable cutting tool according to  claim 1  wherein the tip is formed from a cemented carbide or other wear resistant material.  
   
   
       15 . The rotatable cutting tool according to  claim 1  wherein the hard tip is formed separately from the shank and body of the rotatable cutting tool and inserted into a recess at the leading end of the body.  
   
   
       16 . The rotatable cutting tool according to  claim 1  wherein the rotatable cutting tool includes a hard tip in the form of a pyramid, the body of the rotatable cutting tool adjacent to the tip has a polygonal cross-section whereby each apex of the cross-section of the body is generally aligned with an edge of the tip and each face of the tip meets with a corresponding face on the body, and wherein the face on the body is inclined at a lesser angle whereby removal of debris created by the impact of the rotatable cutting tool is not impeded.