Double-sided ball end mill cutting insert and tool therefor

Patent metadata

Field	Value
Publication number	US-9623493-B2
Application number	US-27377408-A
Country	US
Kind code	B2
Filing date	Nov 19, 2008
Priority date	Nov 19, 2008
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

A double-sided ball end mill includes a body having a generally hemispherical forward end portion and a rearward end portion. The forward end portion includes insert-receiving pockets and chip pockets. A cutting insert can be mounted within each insert-receiving pocket. The cutting insert includes a first substantially planar surface, a second substantially planar surface, a first curvilinear side surface, a second curvilinear side surface, a first pair of cutting edges formed at an intersection between the first substantially planar surface and the first and second curvilinear side surfaces, and a second pair of cutting edges formed at an intersection between the second substantially planar surface and the first and second curvilinear side surfaces. The first and second planar surfaces are substantially parallel to each other, and the cutting insert is mirror symmetric about all three axes.

First claim

What is claimed is:

1. A ball end mill, comprising:
a body having a generally hemispherical forward end portion, a rearward end portion and a central axis, the generally hemispherical forward end portion including an insert-receiving pocket, the insert-receiving pocket including a bottom support surface, an axial support surface, a radial support surface, and a free surface between the axial support surface and the radial support surface; and
a cutting insert including a first substantially planar surface, a second substantially planar surface, a first curvilinear side surface, a second curvilinear side surface, a corner radius between the first and second curvilinear side surfaces, a first pair of cutting edges formed at an intersection between the first substantially planar surface and the first and second curvilinear side surfaces, and a second pair of cutting edges formed at an intersection between the second substantially planar surface and the first and second curvilinear side surfaces, wherein the cutting insert is mirror symmetric about all three central x-, y- and z-axes,
wherein the cutting insert is mounted in the insert-receiving pocket in such a way that at least a portion of the cutting insert lies along the central axis of the body.

2. A ball end mill according to claim 1 , wherein the first substantially planar surface and the second substantially planar surface are substantially parallel to each other.

3. A ball end mill according to claim 1 , wherein the insert-receiving pocket further includes a corner relief formed between the bottom support surface and the axial and radial support surfaces.

4. A ball end mill according to claim 1 , wherein the cutting insert further includes a contact area for contacting the axial and radial side support surfaces of the insert-receiving pocket and preventing rotation of the cutting insert when mounted in the insert-receiving pocket.

5. A ball end mill according to claim 1 , wherein the cutting insert further includes a contact area for contacting the axial and radial side support surfaces of the insert-receiving pocket and preventing rotation of the cutting insert when mounted in the insert-receiving pocket.

6. A ball end mill according to claim 1 , wherein the generally hemispherical forward end further includes a chip pocket.

7. A ball end mill according to claim 1 , further comprising one or more coolant passages formed in the body.

8. A ball end mill, comprising:
a body having a generally hemispherical forward end portion, a rearward end portion and a central axis, the generally hemispherical forward end portion including an insert-receiving pocket, the insert-receiving pocket including a bottom support surface, an axial support surface and a radial support surface, at least one of the axial support surface and the radial support surface having a contact area defined by a protrusion; and
a cutting insert including a first substantially planar surface, a second substantially planar surface, a first curvilinear side surface extending between the first and second substantially planar surfaces, a second curvilinear side surface extending between the first and second substantially planar surfaces, a corner radius between the first and second curvilinear side surfaces, at least one of the first curvilinear side surface and the second curvilinear side surface having at least one contact area defined by a recess that contacts the at least one contact area of the insert-receiving pocket when the cutting insert is mounted in the insert-receiving pocket, a first pair of cutting edges formed at an intersection between the first substantially planar surface and the first and second curvilinear side surfaces, and a second pair of cutting edges formed at an intersection between the second substantially planar surface and the first and second curvilinear side surfaces, wherein the cutting insert is mirror symmetric about all three central x-, y- and z-axes,
wherein the cutting insert is mounted in the insert-receiving pocket in such a way that at least a portion of the cutting insert lies along the central axis of the body.

9. The ball end mill of claim 8 , wherein the second curvilinear side surface has two contact areas and the first curvilinear side surface has two contact areas.

10. A ball end mill, comprising:
a body having a generally hemispherical forward end portion, a rearward end portion and a central axis, the generally hemispherical forward end portion including an insert-receiving pocket, the insert-receiving pocket including a bottom support surface, an axial support surface having a polygonal-shaped protrusion extending therefrom, and a radial support surface having a polygonal-shaped protrusion extending therefrom; and
a cutting insert including a first substantially planar surface, a second substantially planar surface, a first curvilinear side surface between the first and second substantially planar surfaces, a second curvilinear side surface between the first and second substantially planar surfaces and recesses, a corner radius between the first and second curvilinear side surfaces, a first pair of cutting edges formed at an intersection between the first substantially planar surface and the first and second curvilinear side surfaces, and a second pair of cutting edges formed at an intersection between the second substantially planar surface and the first and second curvilinear side surfaces, wherein the cutting insert is mirror symmetric about all three central x-, y- and z-axes,
wherein the first curvilinear side surface and the second curvilinear side surface each has a recess corresponding in shape to the polygonal shaped protrusion of the insert-receiving pocket, whereby the polygonal shaped protrusion of the insert-receiving pocket mates with at least one of the recesses of the cutting insert to prevent rotational movement of the cutting insert when the cutting insert is mounted in the insert-receiving pocket, and
wherein the cutting insert is mounted in the insert-receiving pocket in such a way that at least a portion of the cutting insert lies along the central axis of the body.

11. The ball end mill of claim 10 , wherein the protrusions and recesses are triangular, square, rectangular, or diamond in cross-sectional shape.

Assignees

• Morrison Michael G
• Bontha Srikanth
• Kennametal Inc

Inventors

• Morrison Michael G
• Bontha Srikanth

Classifications

• B23C5/2213 Primary

  having a special shape · CPC title

• B23C2200/128

  with one or more grooves · CPC title

• Y10T407/1924

  Specified tool shape · CPC title

• Y10T407/235

  with integral chip breaker, guide or deflector · CPC title

• B23C2200/203

  Curved cutting edges · CPC title