Patent ID: 7695221
Filing Date: 2010-04-13
Classification: B23B,Y10S,Y10T

Abstract:
1. An outer insert for a drilling tool which can be used in a machine tool, having at least one main cutting edge, extending between a first and a second insert corner, and an adjacent secondary cutting edge adjoining the first insert corner, wherein the main cutting edge is subdivided in its longitudinal extent into a rectilinear working section and an adjoining rectilinear peeling section extending up to the first insert corner, said sections enclosing an angle of 90°+δ with one another, wherein in a region of the first insert corner, the peeling section of the main cutting edge and the adjacent secondary cutting edge enclose an angle of 180°−δ with one another, wherein a central section extending up to the second insert corner adjoins the rectilinear working section of the main cutting edge, the central section enclosing a sweepback angle of 180°−δ with the working section, wherein δ is in the range of 5° to 20°, and wherein the outer insert comprises an indexable insert having third and fourth insert corners and four identical ones of said main cutting edges which are offset from adjacent ones of said main cutting edges by 90° and wherein in use a relevant said main cutting edge adjoining a relevant said corresponding insert corner performs the function of the secondary cutting edge with regard to another relevant said main cutting edge that functions as the main cutting edge.