The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 02, 2013
Filed:
Jun. 16, 2009
Stephen Michael George, Evans, GA (US);
Stephen Michael George, Evans, GA (US);
Kennametal Inc., Latrobe, PA (US);
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.