U.S. patent application number 11/821708 was filed with the patent office on 2008-12-25 for round cutting insert with chip control feature.
Invention is credited to Kenneth L. Niebauer, Keith R. Zack.
Application Number | 20080317558 11/821708 |
Document ID | / |
Family ID | 40073735 |
Filed Date | 2008-12-25 |
United States Patent
Application |
20080317558 |
Kind Code |
A1 |
Niebauer; Kenneth L. ; et
al. |
December 25, 2008 |
ROUND CUTTING INSERT WITH CHIP CONTROL FEATURE
Abstract
A round cutting insert includes a bottom surface, a clearance
side surface and a top surface. The top surface includes a chip
control feature in the form of a continuous, circumferential
depression formed by a substantially planar bottom surface and a
pair of upward sloping substantially planar side walls that form an
angle with respect to the top surface. The chip control feature may
also include a plurality of radially offset bumps located in the
depression. The bumps may have the same size and shape, or may have
a different size and shape. The top surface also includes an
elevated island having one or more indexing marks for easy indexing
of the cutting insert.
Inventors: |
Niebauer; Kenneth L.;
(Ligonier, PA) ; Zack; Keith R.; (Homer City,
PA) |
Correspondence
Address: |
KENNAMETAL INC.;Intellectual Property Department
P.O. BOX 231, 1600 TECHNOLOGY WAY
LATROBE
PA
15650
US
|
Family ID: |
40073735 |
Appl. No.: |
11/821708 |
Filed: |
June 25, 2007 |
Current U.S.
Class: |
407/114 |
Current CPC
Class: |
B23B 27/143 20130101;
Y10T 407/23 20150115; Y10T 407/245 20150115; B23B 2200/3627
20130101; B23B 2200/0461 20130101; B23B 2260/104 20130101; Y10T
407/24 20150115; B23B 2200/087 20130101; B23B 2200/321 20130101;
B23B 2200/242 20130101; Y10T 407/235 20150115 |
Class at
Publication: |
407/114 |
International
Class: |
B23B 27/22 20060101
B23B027/22 |
Claims
1. A round cutting insert, comprising: a bottom surface; a
clearance side surface; a top surface including a chip control
feature in the form of a continuous, circumferential depression
having a plurality of bumps located in the depression; a cutting
edge formed at an intersection between the top surface and the
clearance side surface; and a substantially flat downwardly sloping
facet interposed between one of the side walls of the depression
and the cutting edge, the facet forming an angle with respect to
the top surface, wherein a first bump is located at a first
distance from the cutting edge, and wherein a second bump is
located at a second distance from the cutting edge, the second
distance being different than the first distance.
2. A cutting insert according to claim 1, wherein at least one bump
is different in size than another bump
3. A cutting insert according to claim 1, wherein the plurality of
bumps are teardrop in shape.
4. A cutting insert according to claim 1, wherein the depression
comprises a substantially planar bottom surface, and a pair of
upward sloping substantially planar side walls, each side wall
forming an angle with respect to the top surface.
5. A cutting insert according to claim 4, wherein the angle formed
by one side wall is different than the angle formed by the other
side wall.
6-7. (canceled)
8. A cutting insert according to claim 1, wherein the top surface
further comprises an elevated island having one or more indexing
marks for indexing the cutting insert.
9. A round cutting insert, comprising: a bottom surface; a
clearance side surface; a top surface including a chip control
feature in the form of a continuous, circumferential depression
comprising a substantially planar bottom surface, and a pair of
upward sloping substantially planar side walls, each side wall
forming an angle with respect to the top surface, and a plurality
of bumps located in the depression, wherein at least one bump is
different in size than another bump; a cutting edge formed at an
intersection between the top surface and the clearance side
surface; and a substantially flat downwardly sloping facet
interposed between one of the side walls of the depression and the
cutting edge, the facet forming an angle with respect to the top
surface.
10. A cutting insert according to claim 9, wherein a cutting edge
formed at an intersection between the top surface and the clearance
side surface, and wherein at least one bump is located at a first
distance from the cutting edge, and wherein a second bump is
located at a second distance from the cutting edge, the second
distance being different than the first distance.
11. (canceled)
12. A cutting insert according to claim 9, wherein the plurality of
bumps are teardrop in shape.
13. A cutting insert according to claim 9, wherein the angle formed
by one side wall is different than the angle formed by the other
side wall.
14-15. (canceled)
16. A cutting insert according to claim 9, wherein the top surface
further comprises an elevated island having one or more indexing
marks for indexing the cutting insert.
17. A round cutting insert, comprising: a bottom surface; a
clearance side surface; a top surface including a chip control
feature in the form of a continuous, circumferential depression
comprising a substantially planar bottom surface, and a pair of
upward sloping substantially planar side walls, each side wall
forming an angle with respect to the top surface, and a plurality
of bumps located in the depression; and a substantially flat
downwardly sloping facet interposed between one of the side walls
of the depression and the cutting edge, the facet forming an angle
with respect to the top surface.
18. A cutting insert according to claim 17, wherein at least one
bump is different in size than another bump.
19. A cutting insert according to claim 17, wherein the angle
formed by one side wall is different than the angle formed by the
other side wall.
20. (canceled)
21. A cutting insert according to claim 17 wherein at least one
bump is radially offset with respect to another bump.
22. A cutting insert according to claim 17, wherein at least one
bump is different in size than another bump.
Description
BACKGROUND OF THE INVENTION
[0001] Round cutting inserts may often manage a number of profiling
operations from fine machining to rough machining. Usually, the
round cutting inserts generate a fine surface also in connection
with high feeding since the round edge functions as a wiper.
However, the chip control may easily become deficient, especially
in connection with small cutting depths when relatively wide and
thin chips are formed that could be hard to break. Thereby, long
curled chips are formed that at worst may entangle around the
insert holder and scratch the generated surface and possibly cause
insert breakdown. Further, round inserts are afflicted with the
inherent disadvantage that it is not possible to select an entering
angle at a certain cutting depth because the insert is round. Thus,
there is a need to provide a round insert with improved chip
control for a desired entering angle and a desired cutting
depth.
BRIEF SUMMARY OF THE INVENTION
[0002] Briefly, according to this invention, there is provided a
round cutting insert comprising a bottom surface; a clearance side
surface; and a top surface including a chip control feature in the
form of a continuous, circumferential depression having a plurality
of radially offset bumps located in the depression.
[0003] In another embodiment, a round cutting insert comprises a
bottom surface; a clearance side surface; and a top surface
including a chip control feature in the form of a continuous,
circumferential depression comprising a substantially planar bottom
surface, and a pair of upward sloping substantially planar side
walls, each side wall forming an angle with respect to the top
surface, and a plurality of bumps located in the depression.
[0004] In yet another embodiment, a round cutting insert comprises
a bottom surface; a clearance side surface; and a top surface
including a chip control feature in the form of a continuous,
circumferential depression comprising a substantially planar bottom
surface, and a pair of upward sloping substantially planar side
walls, each side wall forming an angle with respect to the top
surface, and a plurality of radially offset bumps located in the
depression, the top surface further comprising an elevated island
having one or more indexing marks for indexing the cutting
insert.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] These and other features, aspects, and advantages of the
present invention will become better understood when the following
detailed description is read with reference to the accompanying
drawings in which like characters represent like parts throughout
the drawings, wherein:
[0006] FIG. 1 is a perspective view of a round cutting insert with
chip control feature according to an embodiment of the
invention;
[0007] FIG. 2 is a cross-sectional view of the round cutting insert
taken along line 2-2 of FIG. 1;
[0008] FIG. 3 is an enlarged view of the chip control feature of
the round cutting insert of FIG. 1;
[0009] FIG. 4 is a perspective view of a round cutting insert with
chip control feature according to another embodiment of the
invention;
[0010] FIG. 5 is a cross-sectional view of the round cutting insert
taken along line 5-5 of FIG. 4;
[0011] FIG. 6 is a cross-sectional view of the round cutting insert
taken along line 6-6 of FIG. 4;
[0012] FIG. 7 is a cross-sectional view of the round cutting insert
taken along line 7-7 of FIG. 4;
[0013] FIG. 8 is a cross-sectional view of the round cutting insert
taken along line 8-8 of FIG. 4;
[0014] FIG. 9 is a perspective view of a round cutting insert with
chip control feature according to another embodiment of the
invention;
[0015] FIG. 10 is a cross-sectional view of the round cutting
insert taken along line 10-10 of FIG. 9; and
[0016] FIG. 11 is an enlarged view of the chip control feature of
the round cutting insert of FIG. 9.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Referring now to FIGS. 1-3, a round cutting insert according
to an embodiment is shown generally at 10. The insert 10 generally
comprises a top surface 12, a clearance side surface 14 and a
substantially planar bottom surface 16. The clearance side surface
14 forms a clearance angle 18 (FIG. 2) with respect to the top
surface 12. In one embodiment, the clearance angle 18 may be equal
to zero degrees such that the clearance side surface 14 is
substantially perpendicular to the top surface 12 (and to the
bottom surface 16). In order to provide sufficient clearance for
most applications, the clearance angle 18 is between about +3
degrees and about +15 degrees, preferably between about +4 degrees
and about +12 degrees, and most preferably about +7 degrees. It
will be appreciated that the clearance angle 18 can be zero degrees
to provide a double-sided insert.
[0018] Referring now to FIG. 2, the cutting insert 10 includes a
substantially circular cutting edge 20 at the intersection between
the top surface 12 and the clearance side surface 14 and a
substantially circular bottom edge 22 at the intersection between
the bottom surface 16 and the clearance side surface 14. In the
illustrated embodiment, the clearance angle 18 is a positive value
so that the diameter of the substantially circular cutting edge 20
is larger than the diameter of the circular bottom edge 22.
[0019] Referring back to FIG. 1, the top surface 12 includes a
substantially planar island 24 that is slightly elevated with
respect to the cutting edge 20. It will be appreciated that the
island 24 may be lower in elevation with respect to the cutting
edge 20 on negative inserts. The island 24 includes one or more
indexing marks 26 that may be similar in shape or different in
shape. In the illustrated embodiment, the island 24 includes three
indexing marks 26 that are substantially identical in shape that
are circumferentially positioned at equidistant intervals of about
120 degrees around the island 24. The indexing marks 26 are used to
properly locate or index the cutting insert 10 at a desired
position with respect to the toolholder (not shown). The cutting
insert 10 may also includes a countersunk bore 28 for mounting the
insert 10 to the toolholder (not shown).
[0020] Referring now to FIG. 3, the top surface 12 of the cutting
insert 10 includes a chip control feature in the form of a
continuous, circumferential depression, shown generally at 30. In
the embodiment of FIG. 3, the depression 30 includes a
substantially planar bottom surface 30a having a width W1, and a
pair of upward sloping substantially planar side walls 30b, 30c.
Each side wall 30b, 30c slopes upward at an angle 32, 34 with
respect to the top surface 12, respectively. In the embodiment of
FIG. 3, the angles 32, 34 are substantially identical to each other
at about 25 degrees. However, the invention is not limited by the
magnitude of the angles 32, 34, and the invention can be practiced
at other angles. As seen in FIG. 3, the island 24 is slightly
higher in elevation than the cutting edge 20. However, it will be
appreciated that the island 24 can be slightly lower or the same in
elevation as the cutting edge 20. A substantially flat downwardly
sloping facet 36 forming an angle 38 with respect to the top
surface 12 is interposed between the side wall 30c and the cutting
edge 20. In the embodiment of FIG. 3, the angle 38 is approximately
10 degrees. The depression 30 may also include radii 40, 42
interposed between the bottom surface 30a and the side walls 30b,
30c, respectively. The radii 40, 42 provide a smooth transition
between the bottom surface 30a and the side walls 30b, 30c.
[0021] Referring now to FIGS. 4-8, a round cutting insert 100 is
shown according to another embodiment of the invention. In this
embodiment, the cutting insert 100 is substantially identical to
the cutting insert 10, except that the chip control feature of the
cutting insert 100 includes the depression 30 in combination with a
plurality of chip breaking bumps 102, 104, 106 that bulge or
project upwardly from the bottom surface 30a of the depression 30.
As used herein, a "bump" is defined as something that bulges out or
is protuberant or projects from its surroundings. In the
illustrated embodiment, the bumps 102, 104, 106 form a grouping 108
of three bumps that are mirror symmetric with respect to a grouping
110 of another three bumps. For example, the groupings 108, 110 are
mirror symmetric about the line designated at 120. As shown in FIG.
4, the cutting insert 100 includes a total of six groupings 108 and
six groupings 110, thereby providing a cutting insert that can be
indexed in both left-handed and right-handed machining operations.
It will be appreciated that the invention is not limited by the
number of bumps in the groupings 108, 110, so long as there are at
least two bumps in each grouping.
[0022] As seen in FIG. 4, the bumps 102, 104, 106 in the grouping
108 are radially offset with respect to each other. That is, a
forward end 112 of the bump 102 is located more radially outward
(nearer to the cutting edge 20) at a distance D1 from the cutting
edge 20 than the forward ends 114, 116 of the bumps 104, 106,
respectively. The bump 104 is located more radially outward at a
distance D2 than the bump 106, but is located more radially inward
than the bump 102. Thus, the bump 106 is located more radially
inward at a distance D3 than the bumps 102, 104. The forward ends
112, 114, 116 provide a contact point at which the chip impacts
each bump 102, 104, 106, respectively. As the chip successively
impacts the radially offset contact points at the forward ends 112,
114, 116 of grouping 108, the bumps 102, 104, 106 as the chip flow
across the top surface 12 of the cutting insert 100 in the
direction of the arrow 118, the bumps 102, 104, 106 obstructs the
chip flow and cause the chip to become corrugated in shape.
Conversely, the radially offset bumps in grouping 110 cause the
chip to become corrugated as the chip flows across the top surface
12 of the cutting insert 100 in a direction opposite to the arrow
118.
[0023] In the illustrated embodiment, the centerlines 122, 124, 126
of the chips 102, 104, 106 of grouping 108 are generally
equidistant from each other. However, it will be appreciated that
the invention can be practiced in which the centerlines 122, 124,
126 of the chips 102, 104, 106 are not equidistant from each other.
For example, the centerlines 122, 124 of the bumps 102, 104 may be
equidistant to each other, whereas the centerline 126 of the bump
106 is closer or more distant to the centerline 124 of the bump
104. As will be appreciated, other variations of the distance
between the bumps 102, 104, 106 of each grouping 108, 110 are
within the spirit and scope of the invention.
[0024] The bumps 102, 104, 106 may be the same in size and shape,
or they may be different sizes and shapes. In the illustrated
embodiment in FIG. 4, the bumps 102, 104, 106 are substantially
identical in shape, but different in size. Specifically, the bump
102 is larger than the bumps 104, 106 to provide improved chip
breakage at smaller depth of cut. The bump 104 is larger in size
than the bump 106, but smaller in size than the bump 102 to provide
improved chip breakage at larger depth of cut. Thus, the bump 106
is smaller in size than the bumps 102, 104 to provide improved chip
breakage at even larger depth of cut. The shape of the bumps 102,
104, 106 may be round, oblong, polygonal, conical, teardrop, and
the like. The bumps 102, 104, 106 may be symmetrical or
asymmetrical in shape. In the illustrated embodiment, the bumps
102, 104, 106 have a generally asymmetrical conical or teardrop
shape, as shown in FIGS. 6-8, for improved chip breakage. It is
noted that the indexing marks 26 on the island 24 of the cutting
insert 100 have a plurality of different shapes to allow the user
greater flexibility in properly aligning or indexing the cutting
insert 100 in the toolholder (not shown). In the illustrated
embodiment, a total of six (6) indexing marks 26 are symmetrically
arranged at intervals of about sixty (60) degrees on the island 24
of the top surface 12.
[0025] Referring now to FIGS. 9-11, a round cutting insert 200 is
shown according to another embodiment of the invention. In this
embodiment, the cutting insert 200 includes a chip control feature
in the form of a depression 30' that is somewhat different than the
depression 30 in combination with one or more bumps 202, 204, 206
located in the depression 30'. Specifically, the bottom surface
30'a of the depression 30' has a width W2 that is wider than the
width W1 of the depression 30. In addition, the sidewalls 30'b,
30'c of the depression 30' form different, unequal angles 32', 34',
respectively, with respect to the top surface 12 as compared the
angles 32, 34 formed by the sidewalls 30b, 30c. For example, the
angle 32' may be approximately 20 degrees, while the angle 34' may
be approximately 18 degrees. In addition, the facet 36' on the top
surface 12 of the cutting insert 200 may be wider and form a
different angle 38' as compared to the cutting inserts 10, 100. For
example, the angle 38' may be approximately 21 degrees, while the
angle 38 may be approximately 10 degrees, depending on the
particular cutting operation. Another difference between the
cutting insert 200 and the cutting insert 100 is that the
radially-staggered bumps 202, 204 206 of the cutting insert 200 are
the same shape and the same size, whereas the radially-staggered or
radially offset bumps 102, 104, 106 of the cutting insert 100 are
the same shape, but different size. In addition, the rear end of
each bump 102, 104, 106 (the end opposite the forward end 112, 114,
116) is different in shape than the rear end of each bump 202, 204,
206. However, the forward end 112, 114, 116 of each bump 102, 104,
106 is approximately the same shape as the forward end of each bump
202, 204, 206.
[0026] As described above, a round cutting insert includes a chip
control feature in the form of a continuous, circumferential
depression that may include one or more bumps that provide
additional chip control at various depths of cut.
[0027] The documents, patents and patent applications referred to
herein are hereby incorporated by reference.
[0028] While the invention has been specifically described in
connection with certain specific embodiments thereof, it is to be
understood that this is by way of illustration and not of
limitation, and the scope of the appended claims should be
construed as broadly as the prior art will permit.
* * * * *