Coupling mechanism for cutting tool

Patent metadata

Field	Value
Publication number	US-9643264-B2
Application number	US-201313950407-A
Country	US
Kind code	B2
Filing date	Jul 25, 2013
Priority date	Jul 25, 2013
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

A rotary cutting tool includes a cutter of generally cylindrical shape disposed about a central longitudinal axis. The cutter has a first end having an active fluted portion and an opposite second end, the second end having a male threaded portion disposed thereabout. The cutting tool further includes a shank of generally cylindrical shape disposed about the central longitudinal axis, the shank having a recessed female threaded portion formed in a first end. The male threaded portion includes a number of threads disposed at a first pitch and the female threaded portion includes a number of threads disposed at a second pitch different than the first pitch. The cutter and the shank are selectively coupled via threaded engagement of the male threaded portion and the female threaded portion.

First claim

What is claimed is:

1. A rotary cutting tool comprising:
a cutter of generally cylindrical shape disposed about a central longitudinal axis, the cutter having a first end having an active fluted portion and an opposite second end, the second end having a male threaded portion disposed thereabout; and
a shank of generally cylindrical shape disposed about the central longitudinal axis, the shank having a recessed female threaded portion formed in a first end;
wherein the male threaded portion includes a number of threads disposed at a first pitch and the female threaded portion includes a number of threads disposed at a second pitch different than the first pitch;
wherein the difference between the first pitch and the second pitch is in the range of about 0.002 to about 0.010 mm;
the second pitch being generally constant along the female threaded portion;
the first pitch being generally constant along the male threaded portion;
wherein the cutter includes an axial stop shoulder and the shank includes an axial stop surface;
wherein, in an assembled state:
the cutter and the shank are selectively coupled via threaded engagement of the male threaded portion and the female threaded portion; and
the axial stop shoulder of the cutter abuts the axial stop surface of the shank;

wherein the male threaded portion includes a thread closest to the axial stop shoulder; and
in the assembled state, stress concentration at the thread closest to the axial stop shoulder is avoided.

2. The rotary cutting tool of claim 1 wherein the first pitch is less than the second pitch.

3. The rotary cutting tool of claim 2 wherein the first pitch is about 0.005 mm less than the second pitch.

4. The rotary cutting tool of claim 1 wherein the cutter is formed from a carbide material and wherein the shank is formed from a tool steel.

5. The rotary cutting tool of claim 1 wherein:
the cutter comprises an outward facing circumferential surface having an outward dimension and extending a distance along the central longitudinal axis disposed between the active fluted portion and the male threaded portion;
the shank comprises an inward facing circumferential surface having an inward dimension and extending a distance along the central longitudinal axis between the female threaded portion and the first end of the shank; and
the outward facing circumferential surface is disposed adjacent to, and faces, the inward facing circumferential surface when the male threaded portion and the female threaded portion are threadedly engaged;
the cutter being formed from a cutter carbide material and the shank being formed from a shank carbide material;
wherein the outward dimension is about equal to the inward dimension.

6. The rotary cutting tool of claim 5 , wherein the outward facing circumferential surface is generally in the form of a portion of a truncated cone disposed at a first angle with respect to the central longitudinal axis, and wherein the inward facing circumferential surface is generally in the form of a portion of a truncated cone disposed at a second angle with respect to the central longitudinal axis.

7. The rotary cutting tool of claim 6 wherein the first angle is in the range of about 1° to about 7°.

8. The rotary cutting tool of claim 7 wherein the second angle is in the range of about 1° to about 7°.

9. The rotary cutting tool of claim 5 , wherein the outward facing circumferential surface is generally a cylindrical surface disposed parallel to the central longitudinal axis, and wherein the inward facing circumferential surface is generally a cylindrical surface disposed parallel to the central longitudinal axis.

10. The rotary cutting tool of claim 1 wherein:
the cutter comprises an outward facing circumferential surface extending a distance along the central longitudinal axis disposed adjacent the male threaded portion and opposite the active fluted portion;
the shank comprises an inward facing circumferential surface extending a distance along the central longitudinal axis adjacent the female threaded portion opposite the first end of the shank; and
the outward facing circumferential surface is disposed adjacent to, and faces the inward facing circumferential surface when the male threaded portion and the female threaded portion are threadedly engaged.

11. The rotary cutting tool of claim 10 wherein the outward facing circumferential surface is disposed at an angle in the range of 0° to about 6° with respect to the central longitudinal axis.

12. The rotary cutting tool of claim 11 wherein the inward facing circumferential surface is disposed within the range of 0° to 2° of the angle of the outward facing circumferential surface.

13. The rotary cutting tool of claim 1 wherein:
the cutter comprises a first outward facing circumferential surface extending a distance along the central longitudinal axis disposed between the active fluted portion and the male threaded portion and a second outward facing generally cylindrical circumferential surface extending a distance along the central longitudinal axis adjacent the male threaded portion and opposite the active fluted portion;
the shank comprises a first inward facing circumferential surface extending a distance along the central longitudinal axis between the female threaded portion and the first end of the shank and a second inward facing generally cylindrical circumferential surface extending a distance along the central longitudinal axis adjacent the female threaded portion opposite the first end of the shank;
the first outward facing circumferential surface is disposed adjacent to, and faces, the first inward facing circumferential surface when the male threaded portion and the female threaded portion are threadedly engaged; and
the second outward facing generally cylindrical circumferential surface is disposed adjacent to, and faces, the second inward facing generally cylindrical circumferential surface when the male threaded portion and the female threaded portion are threadedly engaged;
the second outward facing generally cylindrical circumferential surface having a second outward dimension, the second inward facing generally cylindrical circumferential surface having a second inward dimension;
the second outward dimension being equal to or less than the second inward dimension.

14. A rotary cutting tool comprising:
a cutter of generally cylindrical shape disposed about a central longitudinal axis, the cutter having a first end having an active fluted portion and an opposite second end, the second end having a male threaded portion disposed thereabout; and
a shank of generally cylindrical shape disposed about the central longitudinal axis, the shank having a recessed female threaded portion formed in a first end;
wherein the male threaded portion includes a number of threads disposed at a first pitch and at a first taper angle;
wherein the female threaded portion includes a number of threads disposed at a second pitch and at a second taper angle different than the first taper angle;
wherein the second pitch is different from the first pitch;
wherein the difference between the first pitch and the second pitch is in the range of about 0.002 to about 0.010 mm;
the second pitch being generally constant along the female threaded portion;
the first pitch being generally constant along the male threaded portion;
wherein the cutter includes an axial stop shoulder and the shank includes an axial stop surface;
wherein, in an assembled state:
the cutter and the shank are selectively coupled via threaded engagement of the male threaded portion and the female threaded por

Assignees

• Kennametal Inc

Inventors

• Frota De Souza Ruy
• Sharivker Leonid B
• Boulakhov Sergei
• Gey Christoph
• Harush Yosi
• Bookheimer Alan
• Levy Uzi
• George stephen michael

Classifications

• B23B51/00

  Tools for drilling machines · CPC title

• Y10T408/907

  including detailed shank · CPC title

• Y10T407/1906

  including holder [i.e., head] having seat for inserted tool · CPC title

• B23D77/00

  Reaming tools · CPC title

• B23C2210/02

  Connections between the shanks and detachable cutting heads · CPC title