Kennametal Inc.

Michael D Shultz

Bernhard Walter Borschert

Robert Alfred Erickson

Michael R McCormick

Jürgen Schwägerl

Dieter Mühlfriedel

Ruy Frota De Souza

Stephen Michael George

Juergen Schwaegerl

Tilo Krieg

Larry R Meenan

Raymond E Moring

David L Ford

Jerome C Hanna

Ruy Filho Frota De Souza

Michael R Mccormick

Dieter Muehlfriedel

A tool shank for use with a cutting insert in a rotary cutting tool includes a body having, and adapted to be rotated about, a central longitudinal tool axis, the body having a tip portion structured to receive at least a portion of the cutting insert therein. The shank also includes a pair of chip flutes formed in the body and a pair of recesses, each recess bordering a respective chip flute. Each recess includes a rim portion extending perpendicular to the tool axis and a bearing surface extending at an incline relative to the tool axis. Each rim portion is adapted to engage a corresponding surface on the cutting insert. Each bearing surface is adapted to engage a corresponding bearing surface on the cutting insert in a manner such that the cutting insert is pulled against the body when the rotary cutting tool is rotated about the tool axis.

Rotary cutting tool, such as a drill, comprising an exchangeable cutting insert, and an exchangeable cutting insert

A rotary cutting tool that is composed of a tool shank with at least one chucking groove or chip flute and one exchangeable cutting insert. At the tip of the shank a recess for accommodating the cutting insert is provided. The tool shank, on its circumference, has a limb with a bearing surface that is inclined relative to the tool axis and that corresponds to a likewise inclined bearing surface on a wing of the cutting insert. The inclination of the bearing surfaces produces an axial force that retains the cutting insert on the tool shank.

The present invention is directed to a helical drill configuration that allows substantially flat bottomed holes to be machined. At the cutting end of the body member, there are at least two cutting edges that are symmetrically oriented on opposing sides of the rotational axis of the drill. In an embodiment of the invention, first and second cutting edge portions form a continuous surface which provides strength and tool stability. The height of the second portions of each of the cutting edges remains relatively consistent along the horizontal for formation of a generally flat bottom hole. In the embodiment, a center point is defined by two sloped peak surfaces. A central straight chisel edge is formed by the intersection of the two sloped peak surfaces. The first cutting edge section extends from the chisel edge to the second cutting edge section. The first cutting edge section for both cutting edges is formed by symmetrically thinning the two peak surface. In the invention, stress at the center portion of the helical cutting tool is limited by the chisel edge and first sections of the cutting edge near the center portion having a balanced geometry. The balanced geometry of the helical drill also prevents the drill from wobbling and creating deviations in the hole being formed. The chisel edge may blend with a first curvilinear cutting edge and the first curvilinear cutting edge may also have a positive rake to promote cutting.

Drill for making flat bottom hole

A rotary cutting tool that is composed of a tool shank with at least one chucking groove or chip flute and one exchangeable cutting insert. At the tip of the shank a recess for accommodating the cutting insert is provided. The tool shank, on its circumference, has a limb with a bearing surface that is inclined relative to the tool axis and that corresponds to a likewise inclined bearing surface on a wing of the cutting insert. The inclination of the bearing surfaces produces an axial force that retains the cutting insert on the tool shank. The abstract of the disclosure is submitted herewith as required by 37 C.F.R. &#xa7;1.72(b). As stated in 37 C.F.R. &#xa7;1.72(b): A brief abstract of the technical disclosure in the specification must commence on a separate sheet, preferably following the claims, under the heading 'Abstract of the Disclosure.' The purpose of the abstract is to enable the Patent and Trademark Office and the public generally to determine quickly from a cursory inspection the nature and gist of the technical disclosure. The abstract shall not be used for interpreting the scope of the claims. Therefore, any statements made relating to the abstract are not intended to limit the claims in any manner and should not be interpreted as limiting the claims in any manner.

A twist drill including a cutting tip having a front flank face, a substantially cylindrical tool body extending rearwardly from the cutting tip, and a shank. The tool body includes a rotational axis therethrough and at least one flute formed on an outer peripheral surface thereof and extending to the front flank face. The at least one flute includes a first helical portion opening to the front flank face and a second helical portion extending from the rear end of the first helical portion toward the rear portion of the tool body. The second helical portion twists in a direction opposite of the first helical portion.

Twist drill

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Derry, PA, United States of America

Michael D Shultz