U.S. patent application number 15/493274 was filed with the patent office on 2018-10-25 for ramping insert having non-positive cutting geometry and ramping tool.
The applicant listed for this patent is Iscar, Ltd.. Invention is credited to GIL HECHT.
Application Number | 20180304382 15/493274 |
Document ID | / |
Family ID | 62063124 |
Filed Date | 2018-10-25 |
United States Patent
Application |
20180304382 |
Kind Code |
A1 |
HECHT; GIL |
October 25, 2018 |
RAMPING INSERT HAVING NON-POSITIVE CUTTING GEOMETRY AND RAMPING
TOOL
Abstract
A double-sided, indexable, non-positive ramping insert has a
180-degree rotational symmetry about each of the first, second and
third axes of a three-dimensional Euclidean space. The ramping
insert includes two first surfaces and an insert peripheral surface
which extends therebetween. The ramping insert includes four
cutting portions, each includes a major cutting edge, a wiper edge
connected transversely thereto via a corner cutting edge and a
ramping edge which extends transversely from the wiper edge in a
view parallel to the first axis. Each peripheral surface includes
four non-positive ramping relief surfaces, each of which extends
from a respective ramping edge towards, and not beyond, a first
median plane which is defined by the second and third axes.
Inventors: |
HECHT; GIL; (Nahariya,
IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Iscar, Ltd. |
Tefen |
|
IL |
|
|
Family ID: |
62063124 |
Appl. No.: |
15/493274 |
Filed: |
April 21, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B23C 2200/126 20130101;
B23C 2200/367 20130101; B23C 2200/283 20130101; B23C 5/2221
20130101; B23C 2200/0494 20130101; B23C 2200/286 20130101; B23C
2200/085 20130101; B23C 2200/125 20130101 |
International
Class: |
B23C 5/22 20060101
B23C005/22 |
Claims
1. A double-sided, indexable, non-positive ramping insert (14)
having a 180-degree rotational symmetry about each of the first,
second and third axes (X, Y, Z) of a three-dimensional Euclidean
space, a first median plane (XP) defined by the second and third
axes (Y, Z), a second median plane (YP) defined by the first and
third axes (X, Z) and a third median plane (ZP) defined by the
first and second axes (X, Y), the ramping insert (14) comprising
two first surfaces (24) located on opposite sides of the first
median plane (XP), and an insert peripheral surface (26) extending
between the first surfaces (24) and intersecting each first surface
(24) at a peripheral edge (28), each first surface (24) comprising
two raised corners (18a) and two lowered corners (38a), the raised
corners (18a) being farther from the first median plane (XP) than
the lowered corners (38a); the insert peripheral surface (26)
comprising two second surfaces (30) and two third surfaces (32)
extending therebetween, each first surface (24) comprising exactly
two opposite cutting portions (36), each cutting portion (36)
comprising: a major cutting edge (16) formed at an intersection of
the first and second surfaces (24, 30); a corner cutting edge (18)
at one of the raised corners (18a), and a wiper edge (20) connected
to the major cutting edge (16) via the corner cutting edge (18);
wherein, each cutting portion (36) further comprises a ramping edge
(22) extending transversely from the wiper edge (20) in a view
parallel to the first axis (X); and each third surface (32)
comprises only two non-positive ramping relief surfaces (46), each
ramping relief surface (46) extending from a respective ramping
edge (22) towards, but not beyond, the first median plane (XP).
2. The ramping insert (14) according to claim 1, wherein on each
first surface (24), each ramping edge (22) of a first cutting
portion (36) is connected to a major cutting edge (16) of a second
cutting portion (36) via a minor corner edge (38).
3. The ramping insert (14) according to claim 2, wherein, in a view
parallel to the third axis (Z), in each peripheral edge (28), each
minor corner edge (38) is located closer to the first median plane
(XP) than any of the corner cutting edges (18).
4. The ramping insert (14) according to claim 2, wherein, in a view
parallel to the first axis (X), on each first surface (24), the
minor corner edges (38) are closer to the third median plane (ZP)
than the corner cutting edges (18).
5. The ramping insert (14) according to claim 1, wherein in a view
parallel to the first axis (X), the ramping edge (22) is at least
partially spaced apart from an intersection line between the first
median plane (XP) and the third surface (32).
6. The ramping insert (14) according to claim 1, wherein in a view
parallel to the first axis (X), every point of the third surfaces
(32) located on the near side of the first median plane (XP) is
either visible or coincides with the peripheral edge (28) located
on the near side.
7. The ramping insert (14) according to claim 1, wherein a clamping
hole (34) extends between, and opens out to, either the first
surfaces (24) or to the opposing second surfaces (30).
8. The ramping insert (14) according to claim 1, wherein each first
surface (24) comprises a first abutment surface (48) which is
parallel to the first median plane (XP).
9. The ramping insert (14) according to claim 1, wherein each first
surface (24) comprises first abutment sub-surfaces (49) which are
transverse to the first median plane (XP)
10. The ramping insert (14) according to claim 1, wherein each
second surface (30) comprises a planar second abutment surface (50)
which is parallel to the second median plane (YP).
11. The ramping insert (14) according to claim 1, wherein each
third surface (32) comprises a planar third abutment surface (52)
which is parallel to the third median plane (ZP).
12. The ramping insert (14) according to claim 1, wherein each
second surface (30) comprises two major relief surfaces (39), each
major relief surfaces (39) extending from an associated major
cutting edge (16), transversely to the second median plane
(YP).
13. The ramping insert (14) according to claim 1, wherein each
third surface (32) comprises two wiper relief surfaces (42), each
of which extends from an associated wiper edge (20) towards, but
does not extend past, the first median plane (XP).
14. The ramping insert (14) according to claim 13, further
comprising a third abutment surface (52) which extends between the
wiper relief surfaces (42).
15. The ramping insert (14) according to claim 1, wherein each
ramping relief surface (46) is either perpendicular to, or forms an
acute internal ramping relief angle ((3) with, the third median
plane (ZP).
16. The ramping insert (14) according to claim 1, wherein: each
third surface (32) comprises wiper relief surfaces (42) which
extend towards the first median plane (XP) from respective wiper
edges; and wherein the wiper relief surface (42) and the ramping
relief surface (46) belonging to the same third surface (32) are
not co-planar.
17. The ramping insert (14) according to claim 1, wherein in a view
parallel to the first axis (X) when proceeding along the ramping
edge (22) starting from the wiper edge (20), each successive point
is located closer to the third median plane (ZP) than the one
before it.
18. The ramping insert (14) according to claim 1, wherein in a view
parallel to the first axis (X), the ramping edge (22) appears
straight and forms an acute ramping angle (a) with the third median
plane (ZP).
19. The ramping insert (14) according to claim 1, wherein the
ramping edge (22) is continuous.
20. The ramping insert (14) according to claim 1, wherein in any
cross section of any one of the third surfaces (32) taken parallel
to the second median plane (YP), when proceeding along said one
third surface (32) away from the first median plane (XP), each
successive point is located either at the same distance from, or
closer to, the third median plane (ZP), with respect to a point
before it.
21. The ramping insert (14) according to claim 1, wherein in any
cross section of any one of the second surfaces (30) taken parallel
to the third median plane (ZP), when proceeding along said one
second surface (30) away from the first median plane (XP), each
successive point is located either at the same distance from, or
closer to, the second median plane (YP) with respect to a point
before it.
22. The ramping insert (14) according to claim 1, wherein the major
cutting edge (16) is longer than the ramping edge (22) and the
ramping edge (22) is longer than wiper edge (20).
23. The ramping insert (14) according to claim 1, wherein the
ramping insert (14) has at least a 180-degree cutting edge
rotational symmetry, with respect to all three of the first, second
and third axes (X, Y, Z).
24. The ramping insert (14) according to claim 23, wherein the
rotational symmetry does not relate to non-functional geometry.
25. The ramping insert (14) according to claim 23, wherein the
rotational symmetry does not relate to chip breaking or deflecting
surfaces.
26. The ramping insert (14) according to claim 1, wherein the
ramping insert (14) is configured for milling an exactly 90 degree
shoulder in a workpiece.
27. The ramping insert (14) according to claim 1, wherein in a view
parallel to the first axis (X), a straight tangent line (T) which
is tangent to any point of the ramping edge (22) forms an acute
ramping angle (a) smaller than 20 degrees, with the third median
plane (ZP).
28. The ramping insert (14) according to claim 1, wherein when
proceeding along the ramping edge (22) away from the wiper edge
(20), the ramping edge (22) increases in proximity to the first
median plane (XP).
29. The ramping insert (14) according to claim 1, wherein the
ramping relief surfaces (46) constitute non-ground surfaces.
30. A ramping tool (10) having opposite machining and coupling ends
(56, 58), wherein the machining end (56) comprises at least one
pocket (12) having a ramping insert (14) according to claim 1
retained therein.
31. The ramping tool (10) according to claim 30, wherein the at
least one pocket (12) comprises: a second pocket abutment surface
(60) with a threaded screw hole (66) which opens out thereto; first
and third pocket abutment surfaces (62, 64) extending transversely
away from the first pocket abutment (60) surface; and a clamping
screw (68) configured to clamp the ramping insert (14) in the
pocket (12).
32. The ramping tool (10) according to claim 31, wherein: in the
cutting insert: each first surface (24) comprises a planar first
abutment sub-surface (49) which is transverse to the first median
plane (XP), each second surface (30) comprises a planar second
abutment surface (50) which is parallel to the second median plane
(YP), each third surface (32) comprises a planar third abutment
surface (52) which is parallel to the third median plane (ZP), and
a clamping hole (34) extends between, and opens out to, either the
opposing first surfaces (24) or to the opposing second surfaces
(30), the insert's first abutment surface (48) abuts the first
pocket abutment surface (62), the insert's second abutment surface
(50) abuts the second pocket abutment surface (60) and the insert's
third abutment surface (52) abuts the third pocket abutment surface
(64); and the clamping screw (68) is screw threaded in the screw
hole (66) and located in the clamping bore (34).
33. A double-sided, indexable, non-positive ramping insert (14)
having a 180-degree rotational symmetry about each of the first,
second and third axes (X, Y, Z) of a three-dimensional Euclidean
space, a first median plane (XP) defined by the second and third
axes (Y, Z), a second median plane (YP) defined by the first and
third axes (X, Z) and a third median plane (ZP) defined by the
first and second axes (X, Y), the ramping insert (14) comprising
two first surfaces (24) located on opposite sides of the first
median plane (XP), and an insert peripheral surface (26) extending
between the first surfaces (24) and intersecting each first surface
(24) at a peripheral edge (28), each first surface (24) comprising
two raised corners (18a) and two lowered corners (38a), the raised
corners (18a) being farther from the first median plane (XP) than
the lowered corners (38a); the insert peripheral surface (26)
comprising two second surfaces (30) and two third surfaces (32)
extending therebetween, each first surface (24) comprising exactly
two opposite cutting portions (36), each cutting portion (36)
comprising: a major cutting edge (16) formed at an intersection of
the first and second surfaces (24, 30); a corner cutting edge (18);
and a wiper edge (20) connected transversely to the major cutting
edge (16) via the corner cutting edge (18); wherein, each cutting
portion (36) further comprises a ramping edge (22) extending
transversely from the wiper edge (20) in a view parallel to the
first axis (X); and wherein in any cross section of any one of the
third surfaces (32) taken parallel to the second median plane (YP),
when proceeding along said one third surface (32) away from the
first median plane (XP), each successive point is located either at
the same distance from, or closer to, the third median plane (ZP)
with respect to a point before it.
34. The ramping insert (14) according to claim 33, wherein each
ramping edge (22) has an associated non-ground ramping relief
surface (46) formed in the third surface (32).
Description
FIELD OF THE INVENTION
[0001] The subject matter of the present application relates to
ramping tools. Specifically, it relates to milling, or ramping,
inserts with ramping cutting edges.
BACKGROUND OF THE INVENTION
[0002] U.S. Pat. No. 7,241,082 discloses an insert from the general
field of milling, which does not include ramping cutting edges or
ramping abilities. The ramping insert has almost no ground
surfaces. In other words, the ramping insert is pressed-to-size,
which also means that all edges, including the cutting edges, are
pressed accurately enough, such that grinding is not required.
[0003] As will be explained below, aside from the above
pressed-to-size advantage, the pressing method includes
dies/molds/punches movement only along a single axis. Specifically,
there is used a split die method as disclosed in U.S. Pat. No.
7,560,068. This single-axis type pressing method enables a low
number of die/punch parts, increases production simplicity and
therefore considerably lowers productions costs. As will be
explained below, these abovementioned advantages are maintained,
while introducing a new feature combination and geometry, which
enables ramping capabilities for the known ramping insert.
SUMMARY OF THE INVENTION
[0004] In accordance with a first aspect of the subject matter of
the present application there is provided a double-sided,
indexable, non-positive ramping insert having a 180-degree
rotational symmetry about each of the first, second and third axes
of a three-dimensional Euclidean space, a first median plane
defined by the second and third axes, a second median plane YP
defined by the first and third axes, and a third median plane
defined by the first and second axes,
[0005] the ramping insert comprising two first surfaces located on
opposite sides of the first median plane, and an insert peripheral
surface extending between the first surfaces and intersecting each
first surface at a peripheral edge,
[0006] each first surface comprising two raised corners and two
lowered corners, the raised corners being farther from the first
median plane than the lowered corners;
[0007] the insert peripheral surface comprising two second surfaces
and two third surfaces extending therebetween,
[0008] each first surface comprising exactly two opposite cutting
portions, each cutting portion comprising: [0009] a major cutting
edge formed at an intersection of the first and second surfaces;
[0010] a corner cutting edge at one of the raised corners, and
[0011] a wiper edge connected to the major cutting edge via the
corner cutting edge; wherein,
[0012] each cutting portion further comprises a ramping edge
extending transversely from the wiper edge in a view parallel to
the first axis; and
[0013] each third surface comprises only two non-positive ramping
relief surfaces, each ramping relief surface extending from a
respective ramping edge towards, but not beyond, the first median
plane.
[0014] In accordance with a third aspect of the subject matter of
the present application there is further provided a ramping tool
having opposite machining and coupling ends, wherein the machining
end comprises a pocket and the ramping insert coupled therein.
[0015] Any of the following features, either alone or in
combination, may be applicable to any of the above aspects of the
subject matter of the application:
[0016] On each first surface, each ramping edge of a first cutting
portion is connected to a major cutting edge of a second cutting
portion via a minor corner edge.
[0017] In each peripheral edge, each minor corner edge is located
closer to the first median plane than any of the major corner
edges.
[0018] On each first surface, the minor corner edges are closer to
a third median plane defined by the first and second axes than the
corner cutting edge.
[0019] In a view parallel to the first axis, the ramping edge is at
least partially spaced apart from an intersection line formed
between the first median plane and the third surface.
[0020] In a view parallel to the first axis, every point of the
third surfaces located on the near side of the first median plane
is either visible or coincides with the peripheral edge closer to
the point of view.
[0021] A clamping hole extends between, and opens out to, either
the first or second surfaces.
[0022] Each first surface comprises a first abutment surface which
is parallel to the first median plane.
[0023] Each first surface can include first abutment sub-surfaces
which are transverse to the first median plane.
[0024] Each second surface can include a planar second abutment
surface which is parallel to a second median plane defined by the
first and third axes.
[0025] Each third surface can include a planar third abutment
surface which is parallel to a third median plane defined by the
first and second axes.
[0026] Each second surface comprises two major relief surfaces,
each extending from an associated major cutting edge, transversely
to a second median plane defined by the first and third axes.
[0027] Each third surface comprises two wiper relief surfaces, each
of which extends from an associated wiper edge towards the first
median plane.
[0028] Each third surface includes wiper relief surfaces which
extend towards the first median plane from respective wiper edges,
and a third abutment surface which extends between the wiper relief
surfaces. The wiper relief surfaces may constitute non-ground
surfaces.
[0029] Each ramping relief surface is either perpendicular or forms
an acute internal ramping relief angle with a third median plane
defined by the first and second axes.
[0030] Each third surface comprises wiper relief surfaces which
extend towards the first median plane from respective wiper edges;
and wherein the wiper relief surface and the ramping relief surface
are not co-planar.
[0031] In a view parallel to the first axis, when proceeding along
the ramping edge starting from the wiper edge, each successive
point is located closer to a third median plane, defined by the
first and second axes, than the one before it.
[0032] In a view parallel to the first axis, the ramping edge
appears straight and forms an acute ramping angle with a third
median plane defined by the first and second axes.
[0033] The ramping edge is continuous.
[0034] A second median plane is defined by the first and third axes
and a third median plane is defined by the first and second axes,
and wherein in any cross section of any of the third surfaces taken
parallel to the second median plane, when proceeding along each
third surface away from the first median plane, each successive
point is located either at the same distance from, or closer to,
the third median plane with respect to a point before it.
[0035] A second median plane is defined by the first and third axes
and third median plane is defined by the first and second axes, and
wherein in any cross section of any of the second surfaces taken
parallel to the third median plane, when proceeding along each
second surface away from the first median plane, each successive
point is located either at the same distance from, or closer to,
the second median plane with respect to a point before it.
[0036] The major cutting edge is longer than the ramping edge and
the ramping edge is longer than wiper edge.
[0037] The ramping insert has at least a 180-degree cutting edge
rotational symmetry.
[0038] The rotational symmetry doesn't include non-functional
geometry.
[0039] The rotational symmetry doesn't include chip breaking or
deflecting surfaces.
[0040] The ramping insert is configured for milling exactly 90
degrees shoulder in a workpiece.
[0041] In a view parallel to the first axis, a straight tangent
line which is tangent to any point of the ramping edge forms a
ramping angle which is smaller than 20 degrees with the third
median plane.
[0042] When proceeding along the ramping edge away from the wiper
edge, the ramping edge increases proximity to the first median
plane.
[0043] Each pocket can include a second pocket abutment surface
with a threaded screw hole which opens out thereto; first and third
pocket abutment surfaces extending transversely away from the first
pocket abutment surface; and a clamping screw configured to clamp
the ramping insert in the pocket.
[0044] In an assembled position of the ramping tool, the first
abutment surface abuts the first pocket abutment surface, the
second abutment surface abuts the second pocket abutment surface
and the third abutment surface abuts the third pocket abutment
surface; and wherein the clamping screw is screw threaded in the
screw hole and located in the clamping bore.
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] For a better understanding of the subject matter of the
present application and to show how the same may be carried out in
practice, reference will now be made to the accompanying drawings,
in which:
[0046] FIG. 1 is an isometric view of a tangential ramping
insert;
[0047] FIG. 2 is a plan view of a first surface of the ramping
insert of FIG. 1;
[0048] FIG. 3 is a plan view of a third surface of the ramping
insert of FIG. 1;
[0049] FIG. 4 is a plan view of a second surface of the ramping
insert of FIG. 1 showing a clamping hole which opens out
thereto;
[0050] FIG. 5 is an isometric view of a radial embodiment of the
ramping insert of FIG. 1 showing the clamping hole opening out to
the first surface;
[0051] FIG. 6 is an isometric view of a ramping tool with another
embodiment of the ramping insert of FIG. 1 secured in a pocket in
an assembled position;
[0052] FIG. 7 is a side view of the ramping tool of FIG. 6;
[0053] FIG. 8 is an axial bottom view of the ramping tool of FIG.
6;
[0054] FIG. 9 is a plan view of the third surface of the ramping
insert of FIG. 6; and
[0055] FIG. 10 is a cross-sectional view taken along line X-X of
FIG. 9 which passes above a ramping relief surface and a wiper
relief surface;
[0056] Where considered appropriate, reference numerals may be
repeated among the figures to indicate corresponding or analogous
elements.
DETAILED DESCRIPTION OF THE INVENTION
[0057] In the following description, various aspects of the subject
matter of the present application will be described. For purposes
of explanation, specific configurations and details are set forth
in sufficient detail to provide a thorough understanding of the
subject matter of the present application. However, it will also be
apparent to one skilled in the art that the subject matter of the
present application can be practiced without the specific
configurations and details presented herein.
[0058] Attention is drawn to FIGS. 1 and 6. A ramping tool 10
includes multiple pockets 12 and ramping inserts 14 secured
therein. The ramping insert 14 and ramping tool 10 are configured
for milling exactly a 90-degree shoulder (within desired
tolerances) in a workpiece as well as performing ramping and wiping
operations. The ramping insert 14 therefore includes at least the
following operational edges: a major cutting edge 16, a corner
cutting edge 18, a wiper edge 20 and a ramping edge 22.
[0059] The ramping insert 14 is typically made from extremely hard
and wear-resistant material such as cemented carbide by
form-pressing and sintering carbide powders in a binder. The
cemented carbide may be, for example, tungsten carbide. The ramping
insert 14 may be coated or uncoated.
[0060] Attention is drawn to FIGS. 1-4. The ramping insert 14 has a
180-degree rotational symmetry about each of the first, second and
third axes X, Y, Z of a three-dimensional Euclidean space. This
rotational symmetry relates to at least the machining, or
operational edges of the ramping insert 14. The ramping insert 14
has a first median plane XP defined by the second and third axes Y,
Z, a second median plane YP defined by the first and third axes X,
Z and a third median plane ZP defined by the first and second axes
X, Y. The ramping insert 14 has at least a 180-degree rotational
symmetry about said axes. For example, the ramping insert 14
doesn't have, a 90-degree symmetry about any of said axes.
[0061] Said rotational symmetry relates at least to functional
machining geometry, such as the ramping edges 22, the corner
cutting edges 18, the wiper edges 20 and the major cutting edge 16.
For example, some functional features such as cutting edge
indication/marking (consecutive) numbers are not included in said
rotational symmetry. Said rotational symmetry further does not
include, or relates to, non-functional geometry such, e.g.,
coloring of the ramping insert 14. Furthermore, said rotational
symmetry does not necessarily include chip breaking, or deflecting,
surfaces.
[0062] The ramping insert 14 has two identical first surfaces 24
located on opposite sides of the first median plane XP. Each first
surface 24 has two raised corners 18a, and two lowered corners 38a,
the raised corners 18a being farther from the first median plane XP
than the lowered corners 38a. The ramping insert 14 has an insert
peripheral surface 26 which extends between the first surfaces 24.
The insert peripheral surface 26 intersects with each first surface
24 at a peripheral edge 28. Each insert peripheral surface 26
includes two second surfaces 30 located on opposite sides of the
second median plane YP. The insert peripheral surface 26 further
includes two third surfaces 32 which are located on opposite sides
of the third median plane ZP. Each third surface 32 extends between
the two second surfaces 30. The ramping insert 14 has a clamping
hole 34 which extends between, and opens out to, either the two
first surfaces 24 (FIG. 1-4), or to the two second surfaces 30
(FIG. 5).
[0063] Attention is drawn to FIGS. 4 and 9-10. The ramping insert
14 is indexable, double sided and non-positive. The term
non-positive is used in the sense that the ramping insert 14 does
not have any positive geometry (such as acute relief angles) and
therefore has either a negative structure/form (known as a negative
insert in the art), and/or a structure which is the opposite of
what is known as a positive structure. Put differently, when
proceeding along the second or third surfaces 30, 32,
perpendicularly away from the first median plane XP, none of the
second or third surfaces 30, 32 extends outwardly away from the
second or third median planes YP, ZP respectively. In other words,
and as will be further explained below, no relief surface which
extends from the peripheral edges 28 forms an obtuse internal angle
(measured internally, within the ramping insert 14) with the second
or third median planes YP, ZP (only, e.g., right or acute internal
angles). During production of the ramping insert 14, once the
form-pressing process is complete, the current novel geometry
ensures an easy, efficient and reliable extraction of a
form-pressed (brittle) green body from a splitting die set which
splits at the first median plane XP.
[0064] Therefore, in any cross section of the second surface 30
taken parallel to the third median plane ZP, when proceeding away
from the first median plane XP, each successive point of the second
surface 30 is located at the same distance from, or closer to, the
second median plane YP than the point before it. Furthermore, in
any cross section of the third surface 32 taken parallel to the
second median plane YP (as seen in FIGS. 9 and 10), when proceeding
away from the first median plane XP, each successive point of the
third surface 32 is located at the same distance from, or closer
to, the third median plane ZP than the point before it.
[0065] The ramping insert 14 has exactly four cutting portions 36.
Each first surface 24 has exactly two diagonally opposite cutting
portions 36. Each cutting portion 36 includes four edges located on
a respective peripheral edge 28 proximate a raised corner 18a.
Namely, the major cutting edge 16; the wiper edge 20 which is
connected to the major cutting edge 16 via a corner cutting edge
18; and a ramping cutting edge, or a ramping edge 22. Each corner
cutting edge 18 has a cutting corner apex 19 which is the highest,
or farthest portion, of the corner cutting edge 18 from the first
median plane XP. The ramping edge 22 connects directly to, and
extends transversely from (in a view parallel to the first axis X),
the wiper edge 20. The wiper edges 20 and ramping edges 22 are not
co-linear. The major cutting edge 16 is longer than the ramping
edge 22. The ramping edge 22 is longer than the wiper edge 20. As
seen in FIGS. 2 and 3, the ramping edges 22 extend on both sides of
the second median plane YP. In some embodiments, the ramping edges
22 can extend along the second axis Y between 5 and 50% of the
insert width W measured between the opposing second surfaces
30.
[0066] At its lowered corners 18a, each first surface 24 includes
exactly two diagonally opposed minor corner edges 38, each of which
extends between every two cutting portions 36. Every minor corner
edge has a minor corner apex 37 which is the highest, or farthest
portion of the minor corner edge 38 from the first median plane XP.
The minor corner edges 38 are located closer to the first median
plane XP than the corner cutting edges 18. The minor corner apexes
37 are located closer to the first median plane XP than the corner
cutting apexes 19. Furthermore, on every first surface 24, the
minor corner edges 38 are closer to the third median plane ZP than
the corner cutting edge 18 (in a view parallel to the first axis
X). Even further, on every first surface 24, the minor corner
apexes 37 are closer to the third median plane ZP than the corner
cutting apexes 17 (in a view parallel to the first axis X). On
every first surface 24, each ramping edge 22 of one cutting portion
36 is connected to a major cutting edge 16 of an adjacent cutting
portion 36 via a minor corner edge 38.
[0067] The major cutting edge 16, corner cutting edge 18 and
ramping edge 22 are all sharp cutting edges configured for removing
material from a workpiece. Contrary thereto, the wiper edge 20 is
not configured to, and incapable of, removing material from a
workpiece but rather to perform wiping and/or smoothing operations
which improve workpiece surface quality. Furthermore, the minor
corner edges 38 are also not configured for any type of machining,
they are non-sharp and incapable of removing material from a
workpiece.
[0068] Each major cutting edge 16 is formed at an intersection
between each first surface 24 and second surface 30. Each second
surface 30 has a major relief surface 39 which extends from the
major cutting edge 16 towards the first median plane XP. Each first
surface 24 has a major rake surface 40 which extends from the major
cutting edge 16 towards the second median plane YP. Each major
cutting edge 16 extends between a minor corner edge 38 and a corner
cutting edge 18. As best seen in FIG. 4, in a view of the second
surface 30 parallel to the second axis Y, the major cutting edge 16
is sloped in the direction of the first median plane XP, from a
corner cutting edge 18 to an adjacent minor corner edge 38. Stated
differently, the major cutting edge 16 extends transversally to the
first median plane XP.
[0069] Each wiper edge 20 is formed at an intersection between the
first and third surfaces 24, 32. The wiper edge 20 extends
transversely to the major cutting edge 16. The corner cutting edge
18 connects the major cutting edge 16 with the wiper edge 20. Each
third surface 32 has a wiper relief surface 42 which extends from
the wiper edge 20 towards the first median plane XP. The wiper
relief surface 42 can be perpendicular to the first median plane
XP. As seen in FIG. 2, when viewing the ramping insert 14 from a
view which is parallel to the first axis X, the wiper relief
surface 42 can appear as a straight line. Each first surface 24 has
a wiper surface 44 which extends from the wiper edge 20.
[0070] Each ramping edge 22 is also formed at an intersection
between the first and third surfaces 24, 32. In a view parallel to
the first axis X, the ramping edge 22 extends transversely from the
wiper edge 20 and can form an acute ramping angle .alpha. with the
third median plane ZP. In other words, when proceeding along the
ramping edge 22 away from the wiper edge 20, the ramping edge 22
increases in proximity to the third median plane ZP. Stated
generally, in a view parallel to the first axis X, a straight
tangent line T which is tangent to any point of the ramping edge 22
forms the ramping angle .alpha. with the third median plane ZP. The
ramping angle receives .alpha. values between 0 and 20 degrees.
[0071] As seen in FIG. 3, each third surface 32 includes a ramping
relief surface 46 which extends from the ramping edge 22 towards,
but not beyond, the first median plane XP. The ramping relief
surface 46 can be perpendicular to the first plane XP (as seen in
FIGS. 3 and 4). Alternatively, the ramping relief surface 46 can
form an acute internal ramping relief angle .beta. with the third
plane ZP (as seen in the cross section of FIG. 10). The wiper
relief surface 42 and the ramping relief surface 46 are not
co-planar.
[0072] This advantageous geometry can be described in terms of what
is visible in certain views, especially FIGS. 1 and 2. For
example--when viewing the ramping insert 14 from a view parallel to
the first axis X, only the ramping relief surfaces 46 closer to the
point of view (i.e., in the foreground in FIG. 2) are visible in
said view. Another example--in said view, the ramping relief
surfaces 46 located on the farthest side of the first median plane
XP from the point of view are invisible. Furthermore, in the same
view, every point of the third surfaces 32 located on the near side
(i.e., foreground in FIG. 2) of the first median plane XP is either
visible or coincides with a visible portion of the peripheral edge
28. Yet another example, in said view, each ramping edge 22 is at
least partially spaced apart from an intersection line L1 between
the first median plane XP and the third surface 32 (e.g., along the
abutment surface 52 seen in FIG. 2 and described further
below).
[0073] Due to the foregoing ramping relief surface geometry, the
fact that each ramping relief surface 46 does not extend past the
first plane XP, and that insert has non-positive geometry for all
cutting edges, the insert may be pressed with a two-part die
without forming undercuts on the green body (especially on the
third surface 32). Also, each ramping relief surface 46 on this
insert is a non-ground ramping relief surface, i.e., one whose
shape is determined by pressing and sintering and without
subsequent grinding. Such non-ground ramping relief surfaces
generally have a surface roughness measurably greater than that of
a ground surface.
[0074] The abovementioned restrictions which relate to the
confinement of the ramping relief surface 46 to one side of the
first plane XP is important at least because in a scenario where at
least a portion of a die (designed to form the ramping relief
surfaces 46 and any other geometry or sub-surface of the third
surface 32 which is not necessarily parallel to the third plane ZP)
extends beyond the die splitting line (or plane XP, which
intersects said line) will inherently include unwanted geometries
(such as corners), which can lead to the following
form-pressing-related problems: (a) Hinder edge and surface
accuracy; (b) Powder leaks (which may lead to grads/superfluous
geometries); (c) Increased costs of die manufacturing; obstruct
repeatability of die-sets matching; and (d) generally reduce
process reliability.
[0075] Each first surface 24 can include a first abutment surface
(FIGS. 1, 6 and 8) 48 which extends between the major rake surfaces
40. The first abutment surface 48 can be planar and oriented
parallel to the first median plane XP (as seen in FIGS. 1 and 2).
The first abutment surface 48 (FIGS. 6 and 8) can include two first
abutment sub-surfaces 49 which converge outwardly away from the
first median plane XP.
[0076] Each second surface 30 includes a second abutment surface 50
which extends between the major relief surfaces 39. The second
abutment surface 50 can be planar and oriented parallel to the
second median plane YP.
[0077] Each third surface 32 includes a third abutment surface 52
which extends between the second surfaces 30. The third abutment
surface 52 can be planar and oriented parallel to the third median
plane ZP. Each third abutment surface 52 can extend between the
wiper relief surfaces 42. According some embodiments, each third
abutment surface 52 and adjacent wiper relief surface 42 are
co-planar. The third abutment surface 52 is always spaced apart
from the ramping edges 22.
[0078] It is understood that each of the first, second and third
abutment surfaces 48, 50, 52 may be ground, to enhance seating.
However, as explained above, the ramping relief surface 46, which
is on the same third surface 32 as the third abutment surface 52,
may constitute a non-ground surface.
[0079] Attention is drawn to FIGS. 6-8. The ramping tool 10 can
have an elongated body 54 or shank and rotates about a tool axis R.
The ramping tool 10 has opposite coupling and machining ends 56,
58. According to some embodiments (e.g., as shown in FIGS. 6-8),
the pockets 12 are tangentially arranged (as will be explained
below) at the machining end 58 around the tool axis R.
[0080] Each pocket 12 has a second pocket abutment surface 60 and
first and third pocket abutment surfaces 62, 64 which extend
transversely to the second pocket abutment surface 60.
[0081] The second pocket abutment surface 60 has a female threaded
screw hole 66 which opens out thereto for receiving a clamping
screw 68. According to the current tangential example (FIG. 7), the
second pocket abutment surface 60 faces away from the rotation axis
R.
[0082] According to some `right-hand` ramping tools (FIG. 8), the
first pocket abutment surface 62 faces in a right-hand rotation
direction and the third pocket abutment surface 64 faces in a
direction parallel to the rotation axis R, away from the coupling
end 56.
[0083] In an assembled position, the ramping insert 14 is seated in
the pocket 12 and the clamping screw 68 is located within the
clamping hole 34 and screw threaded in the screw hole 66 in the
pocket 12. In the assembled position, the clamping and screw holes
34, 66 are eccentric which enables the screw (when tightened) to
force the ramping insert 14 towards the first and third abutment
walls.
[0084] In the assembled position, the first abutment surface 48
abuts the first pocket abutment surface 62, the second abutment
surface 50 abuts the second pocket abutment surface 60 and the
third abutment surface 52 abuts the third pocket abutment surface
64.
* * * * *