Ballnose end mill

Abstract

The present invention relates to tools for the machining of materials by milling or drilling. The invention provides an improved form for an end mill having a semi-spherical cutting end, or flat cutting end, or drill end the center area of which is configured to better eject chips and thus to improve the surface finish of the metal work piece and tool life. The comprising a body portion to be gripped by a machine tool and a plurality of flutes machined to form a cutting tooth adjacent to the flute, each tooth being provided with a chisel edge, the cutting end being semispherical, or flat, or like drill point and when viewed endwise there being seen a cutting edge starting proximate to the tool center at a position B above the x axis and 0.5A to the right of the y axis.

1 . A tool such as a ballnose end mill, or flat end mill, or drill of diameter D configured for improved chip removal, comprising a body portion to be gripped by a machine tool and a plurality of flutes machined to form a cutting tooth adjacent to said flute, each tooth being provided with a chisel edge, the cutting end being semispherical, or flat, or like drill point and when viewed endwise there being seen a cutting edge starting proximate to the cutter center at a position B above the x axis and 0.5A to the right of the y axis, said cutting edge extending at an angle a relative to the y axis for a length C, value of A, being the total off-set between cutting edges of two teeth disposed at 180° to each other, for the machining of different materials is 0.003D to 0.030D, both B and C having lengths of between 0.3A to 1.5A, and the angle a having a value of between 5°-45°.  
   
   
       2 . The tool as claimed in  claim 1 , wherein said cutting edge starting at position B is curved at a radius R, the locus of said radius being at its right side when viewing the upper tooth of the tool's end, and the value of R is 0.5A-5A.  
   
   
       3 . A ballnose end mill, or flat end mill, or drill configured for improved chip removal, substantially as described hereinbefore and with reference to the accompanying drawings.