Invention Grant
US08408850B2 Twist drill with negative axial rake transition between the lip and the secondary cutting edge 有权
在唇缘和次切割边缘之间具有负轴向前刀转角的扭转钻

  • Patent Title: Twist drill with negative axial rake transition between the lip and the secondary cutting edge
  • Patent Title (中): 在唇缘和次切割边缘之间具有负轴向前刀转角的扭转钻
  • Application No.: US12485166
    Application Date: 2009-06-16
  • Publication No.: US08408850B2
    Publication Date: 2013-04-02
  • Inventor: Stephen Michael George
  • Applicant: Stephen Michael George
  • Applicant Address: US PA Latrobe
  • Assignee: Kennametal Inc.
  • Current Assignee: Kennametal Inc.
  • Current Assignee Address: US PA Latrobe
  • Agent Larry R. Meenan, Esq.
  • Main IPC: B23B51/02
  • IPC: B23B51/02
Twist drill with negative axial rake transition between the lip and the secondary cutting edge
Abstract:
A drill for making a hole within a workpiece has a body extending along a longitudinal axis, at least one flute extending along the body, and a drill point extending from the end of the body. The drill point has a periphery and is comprised of a chisel edge, a primary cutting edge extending inwardly from the periphery, a secondary cutting edge extending outwardly from the chisel edge, and a tertiary cutting edge connecting the primary cutting edge with the secondary cutting edge, wherein the tertiary cutting edge has a negative axial rake angle. A method for producing such a drill point is also disclosed wherein in one grinding pass a gash forms the axial rake angle of the secondary cutting edge, and in a separate grinding pass a portion of the secondary cutting edge is removed to produce a tertiary cutting edge having an axial rake angle that is negative.
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