U.S. patent application number 13/591354 was filed with the patent office on 2014-02-27 for cutting tool with insert having a tapered bottom.
This patent application is currently assigned to KENNAMETAL INC.. The applicant listed for this patent is Paul A. Bookhamer, Chad A. Swope. Invention is credited to Paul A. Bookhamer, Chad A. Swope.
Application Number | 20140054951 13/591354 |
Document ID | / |
Family ID | 50069719 |
Filed Date | 2014-02-27 |
United States Patent
Application |
20140054951 |
Kind Code |
A1 |
Bookhamer; Paul A. ; et
al. |
February 27, 2014 |
Cutting Tool With Insert Having A Tapered Bottom
Abstract
A cutting tool for use in impinging earth strata includes a
cutting tool body that contains a socket at an axial forward end
thereof and an insert structured and arranged for being affixed to
the cutting tool body within the socket. The insert includes a
mounting end portion at an axial rearward end of the insert. The
mounting end portion includes a first tapered segment, a second
tapered segment adjacent and axially rearward of the first tapered
segment wherein the second tapered segment has an axial rearward
end diameter, and a base adjacent and axially rearward of the
second tapered segment, the base having a base diameter that is
greater than the axial rearward end diameter of the second tapered
segment. The socket is structured and arranged for cooperating with
the mounting end portion of the insert.
Inventors: |
Bookhamer; Paul A.;
(Altoona, PA) ; Swope; Chad A.; (Bedford,
PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Bookhamer; Paul A.
Swope; Chad A. |
Altoona
Bedford |
PA
PA |
US
US |
|
|
Assignee: |
KENNAMETAL INC.
Latrobe
PA
|
Family ID: |
50069719 |
Appl. No.: |
13/591354 |
Filed: |
August 22, 2012 |
Current U.S.
Class: |
299/113 |
Current CPC
Class: |
E21C 35/183
20130101 |
Class at
Publication: |
299/113 |
International
Class: |
E21C 35/183 20060101
E21C035/183 |
Claims
1. A cutting tool for use in impinging earth strata, the cutting
tool comprising: a cutting tool body with a central longitudinal
axis and having a head portion at an axial forward end, a collar
portion axially rearward of the head portion, and a shank portion
axially rearward of the collar portion at an axial rearward end,
the cutting tool body containing a socket at the axial forward end
thereof; and an insert structured and arranged for being affixed to
the cutting tool body within the socket, the insert having the same
central longitudinal axis as the cutting tool body, the insert
comprising a generally conical tip portion at an axial forward end
of the insert, a central portion adjacent and axially rearward of
the generally conical tip portion and a mounting end portion at an
axial rearward end of the insert, the mounting end portion adjacent
and axially rearward of the central portion, the mounting end
portion comprising: a first tapered segment adjacent and axially
rearward of the central portion; a second tapered segment adjacent
and axially rearward of the first tapered segment, the second
tapered segment having an axial rearward end diameter; and a base
adjacent and axially rearward of the second tapered segment, the
base having a base diameter that is greater than the axial rearward
end diameter of the second tapered segment.
2. The cutting tool of claim 1, wherein the first tapered segment
of the insert tapers inwardly toward the axial rearward end of the
insert.
3. The cutting tool of claim 2, wherein the second tapered segment
of the insert tapers inwardly toward the axial rearward end of the
insert.
4. The cutting tool of claim 1, wherein the first tapered segment
of the insert tapers at a first angle from the central longitudinal
axis.
5. The cutting tool of claim 4, wherein the second tapered segment
of the insert tapers at a second angle from the central
longitudinal axis, wherein the first angle of the first tapered
segment is different from the second angle of the second tapered
segment.
6. The cutting tool of claim 1, wherein the socket defines an
opening at the axial forward end of the cutting tool body and the
socket comprises: a first tapered wall adjacent and axially
rearward of the opening; a second tapered wall adjacent and axially
rearward of the first tapered wall; and a base portion adjacent and
axially rearward of the second tapered wall.
7. The cutting tool of claim 6, wherein the first tapered wall of
the socket is structured and arranged for cooperating with the
first tapered segment of the insert.
8. The cutting tool of claim 7, wherein the second tapered wall of
the socket is structured and arranged for cooperating with the
second tapered segment of the insert.
9. The cutting tool of claim 8, wherein the base portion of the
socket is structured and arranged for cooperating with the base of
the insert.
10. The cutting tool of claim 8, wherein the second tapered wall of
the socket has an axial rearward end diameter and the base portion
of the socket has a base portion diameter that is greater than the
axial rearward end diameter of the second tapered wall.
11. The cutting tool of claim 6, wherein the first tapered wall of
the socket tapers at a first angle from the central longitudinal
axis.
12. The cutting tool of claim 11, wherein the second tapered wall
of the socket tapers at a second angle from the central
longitudinal axis, wherein the first angle of the first tapered
wall is different from the second angle of the second tapered
wall.
13. A cutting tool insert having a central longitudinal axis, the
cutting tool insert comprising: a generally conical tip portion at
an axial forward end of the cutting tool insert; a central portion
adjacent and axially rearward of the generally conical tip portion;
a mounting end portion at an axial rearward end of the cutting tool
insert, the mounting end portion adjacent and axially rearward of
the central portion, the mounting end portion comprising: a first
tapered segment adjacent and axially rearward of the central
portion; a second tapered segment adjacent and axially rearward of
the first tapered segment, the second tapered segment having an
axial rearward end diameter; and a base adjacent and axially
rearward of the second tapered segment, the base having a base
diameter that is greater than the axial rearward end diameter of
the second tapered segment.
14. The cutting tool insert of claim 13, wherein the first tapered
segment tapers inwardly toward the axial rearward end of the
cutting tool insert.
15. The cutting tool insert of claim 14, wherein the second tapered
segment tapers inwardly toward the axial rearward end of the
cutting tool insert.
16. The cutting tool insert of claim 13, wherein the first tapered
segment tapers at a first angle from the central longitudinal axis
of the cutting tool insert.
17. The cutting tool insert of claim 16, wherein the second tapered
segment tapers at a second angle from the central longitudinal axis
of the cutting tool insert, wherein the first angle of the first
tapered segment is different from the second angle of the second
tapered segment.
18. A cutting tool body with a central longitudinal axis, the
cutting tool body comprising: a head portion at an axial forward
end of the cutting tool body, the head portion having a socket that
defines an opening at the axial forward end; a collar portion
axially rearward of the head portion; and a shank portion axially
rearward of the collar portion at an axial rearward end, wherein
the socket comprises: a first tapered wall adjacent and axially
rearward of the opening; a second tapered wall adjacent and axially
rearward of the first tapered wall; and a base portion adjacent and
axially rearward of the second tapered wall.
19. The cutting tool body of claim 18, wherein the second tapered
wall of the socket has an axial rearward end diameter and the base
portion of the socket has a base portion diameter that is greater
than the axial rearward end diameter of the second tapered
wall.
20. The cutting tool body of claim 18, wherein the first tapered
wall of the socket tapers at a first angle from the central
longitudinal axis and the second tapered wall of the socket tapers
at a second angle from the central longitudinal axis, the first
angle of the first tapered wall being different from the second
angle of the second tapered wall.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to cutting tools for impinging
a substrate in, for example, a mining or construction activity.
[0002] Cutting tools are used in conjunction with a machine used to
break up (or cut) a substrate such as coal, rock, asphalt pavement,
asphaltic concrete, concrete or the like. In its very basic
aspects, such a machine includes a driven member (e.g., a chain, a
wheel or a drum), a holder either directly or indirectly mounted to
the driven member, and a rotatable cutting tool rotatably held in
the holder. Typically, the cutting tool has a hard (e.g., cemented
[cobalt] tungsten carbide) insert at the axial forward end thereof
and is rotatably retained by the tool holder. It is the cutting
tool and, more particularly the hard insert that impinges the
substrate so as to break it into pieces upon impact.
[0003] Because of the severe operating environment, the hard
insert, as well as the entire rotatable cutting tool, is subjected
to great forces. These forces can destroy the cutting tool and/or
the hard insert if they do not possess adequate strength and
fracture toughness. Thus, it would be desirable if the design of
the cutting tool and/or the hard insert would enhance the strength
and fracture toughness thereof.
SUMMARY OF THE INVENTION
[0004] In accordance with an aspect of the invention, a cutting
tool for use in impinging earth strata includes a cutting tool body
with a central longitudinal axis and has a head portion at an axial
forward end, a collar portion axially rearward of the head portion,
and a shank portion axially rearward of the collar portion at an
axial rearward end. The cutting tool body contains a socket at the
axial forward end thereof. The cutting tool further includes an
insert structured and arranged for being affixed to the cutting
tool body within the socket, the insert having the same central
longitudinal axis as the cutting tool body. The insert includes a
generally conical tip portion at an axial forward end of the
insert, a central portion adjacent and axially rearward of the
generally conical tip portion and a mounting end portion at an
axial rearward end of the insert wherein the mounting end portion
is adjacent and axially rearward of the central portion. The
mounting end portion includes a first tapered segment adjacent and
axially rearward of the central portion, a second tapered segment
adjacent and axially rearward of the first tapered segment wherein
the second tapered segment has an axial rearward end diameter, and
a base adjacent and axially rearward of the second tapered segment,
the base having a base diameter that is greater than the axial
rearward end diameter of the second tapered segment.
[0005] In accordance with another aspect of the invention, a
cutting tool insert having a central longitudinal axis includes a
generally conical tip portion at an axial forward end of the
insert, a central portion adjacent and axially rearward of the
generally conical tip portion and a mounting end portion at an
axial rearward end of the insert wherein the mounting end portion
is adjacent and axially rearward of the central portion. The
mounting end portion includes a first tapered segment adjacent and
axially rearward of the central portion, a second tapered segment
adjacent and axially rearward of the first tapered segment wherein
the second tapered segment has an axial rearward end diameter, and
a base adjacent and axially rearward of the second tapered segment,
the base having a base diameter that is greater than the axial
rearward end diameter of the second tapered segment.
[0006] In accordance with yet another aspect of the invention, a
cutting tool body with a central longitudinal axis includes a head
portion at an axial forward end of the cutting tool body, the head
portion having a socket that defines an opening at the axial
forward end. The cutting tool body also includes a collar portion
axially rearward of the head portion and a shank portion axially
rearward of the collar portion at an axial rearward end. The socket
includes a first tapered wall adjacent and axially rearward of the
opening, a second tapered wall adjacent and axially rearward of the
first tapered wall, and a base portion adjacent and axially
rearward of the second tapered wall.
[0007] These and other aspects of the present invention will be
more fully understood following a review of this specification and
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a partial sectional side view of a cutting tool,
in accordance with an aspect of the invention.
[0009] FIG. 2 is an enlarged side view of the cutting tool insert
shown in FIG. 1, in accordance with an aspect of the invention.
[0010] FIG. 3 is a partial sectional side view of the cutting tool
body shown in FIG. 1, in accordance with an aspect of the
invention.
DETAILED DESCRIPTION
[0011] Referring to the drawings, there is illustrated a cutting
tool of the invention, generally designated as 10. Exemplary
cutting operations for the cutting tool 10 include, without
limitation, road planing (or milling), coal mining, concrete
cutting, and other kinds of cutting operations wherein a cutting
tool with a hard cutting member impinges against a substrate (e.g.,
earth strata, pavement, asphaltic highway material, concrete, and
the like) breaking the substrate into pieces of a variety of. In
addition, it will be appreciated that the cutting tool 10 of the
invention may be manufactured in various sizes and dimensions
depending upon the desired application of the tool.
[0012] As used herein, the term "cutting tool" generally refers to
rotatable cutting tools or indexable cutting tools that are
generally fixed in place during use.
[0013] Referring to FIG. 1, cutting tool 10 has a central
longitudinal axis A-A. In one aspect, cutting tool 10 may be
symmetrical about and/or rotate about the axis A-A. Cutting tool 10
includes an elongate cutting tool body, generally designated as 12,
which typically is made of steel. Elongate cutting tool body 12
presents a generally cylindrical geometry, and has an axial forward
end 14 and an axial rearward end 16.
[0014] Elongate cutting tool body 12 includes a head portion 18, a
shank portion 20 and a collar portion 22 wherein the collar portion
22 is mediate of and contiguous with the head portion 18 and the
collar portion 22. The collar portion 22 is axially rearward of the
head portion 18 and the shank portion 20 is axially rearward of the
collar portion 22. The shank portion 20 includes an annular groove
24 adjacent the axial rearward end 16 for receiving a retainer ring
(not shown), as is generally known.
[0015] As shown in FIG. 3, the head portion 18 contains a socket 28
at the axial forward end 14 of the cutting tool body 12. The socket
defines an opening 30 at the axial forward end 14 of the cutting
tool body 12. In one aspect, the socket 28 includes a first tapered
wall 32 adjacent and axially rearward of the opening 30, a second
tapered wall 34 adjacent and axially rearward of the first tapered
wall 32, and a base portion 36 adjacent and axially rearward of the
second tapered wall 34.
[0016] The second tapered wall 34 of the socket 28 has an axial
rearward diameter D1, i.e. the diameter at the most axially
rearward portion of the second tapered wall 34 where the second
tapered wall 34 meets the base portion 36. The base portion 36 of
the socket 28 has a base portion diameter, e.g. D2. In one aspect,
the base portion diameter D2 is greater than the axial rearward
diameter D1.
[0017] Still referring to FIG. 3, the first tapered wall 32 of the
socket 28 tapers generally inwardly toward the axial rearward end
16 of the cutting tool body 12. In one aspect, the first tapered
wall 32 tapers at a first angle W from the central longitudinal
axis A-A. The second tapered wall 34 of the socket 28 tapers
generally inwardly toward the axial rearward end 16 of the cutting
tool body 12. In one aspect, the second tapered wall 34 tapers at a
second angle X from the central longitudinal axis A-A. In another
aspect, the first angle W of the first tapered wall 32 is different
from the second angle X of the second tapered wall 34.
[0018] Referring to FIGS. 1 and 2, the cutting tool 10 further
includes a hard cutting member or hard cutting insert, generally
designated as 40. The insert 40 is structured and arranged for
being affixed by, for example, brazing within the socket 28 at the
axial forward end 14 of the cutting tool body 12. When affixed to
the cutting tool body 12, the insert has essentially the same
central longitudinal axis A-A as the cutting tool body 12.
[0019] Referring particularly to FIG. 2, the insert 40 includes an
axial forward end 42 and an axial rearward end 44. Insert 40 may be
made from, for example, a hard material such as, for example,
cemented (cobalt) tungsten carbide. The insert 40 includes a
generally conical tip portion 46 at or adjacent the axial forward
end 42 of the insert 40, a central portion 48 adjacent to and
axially rearward of the generally conical tip portion 46 and a
mounting end portion 50 at the axial rearward end 44 of the insert
40. The mounting end portion 50 is adjacent and axially rearward of
the central portion 48.
[0020] In one aspect, the mounting end portion 50 of the insert 40
includes a first tapered segment 52 adjacent to and axially
rearward of the central portion 48, a second tapered segment 54
adjacent to and axially rearward of the first tapered segment 52
and a base 56 adjacent to and axially rearward of the second
tapered segment 54.
[0021] As shown in FIG. 2, the second tapered segment 54 has an
axial rearward end diameter D3, i.e. the diameter at the most
axially rearward portion of the second tapered segment 54 where the
second tapered segment 54 meets the base 56. The base 56 has a base
diameter, e.g. D4. In one aspect, the base diameter D4 is greater
than the axial rearward end diameter D3 of the second tapered
segment 54.
[0022] Still referring to FIG. 2, the first tapered segment 52 of
the insert 40 tapers generally inwardly toward the axial rearward
end 44 of the insert 40. In one aspect, the first tapered segment
52 tapers at a first angle Y from the central longitudinal axis
A-A. The second tapered segment 54 of the insert 40 tapers
generally inwardly toward the axial rearward end 44 of the insert
40. In one aspect, the second tapered segment 54 tapers at a second
angle Z from the central longitudinal axis A-A. In another aspect,
the first angle Y of the first tapered segment 52 is different from
the second angle Z of the second tapered segment 54.
[0023] FIG. 1 illustrates the insert 40 as positioned or affixed in
place in the socket 28 of the cutting tool body 12. As will be
appreciated, the first tapered wall 32 of the socket 28 is
structured and arranged for cooperating with the first tapered
segment 52 of the insert 40. In addition, the second tapered wall
34 of the socket 28 is structured and arranged for cooperating with
the second tapered segment 54 of the insert 40. Also, the base
portion 36 of the socket 28 is structured and arranged for
cooperating with the base 56 of the insert 40. In addition, it will
be appreciated that the base 56 of the insert 40 and the base
portion 36 of the socket 28 are structured and arranged to have
sufficient dimensional tolerances so that the base 56 of the insert
40 can be inserted into the base portion 36 of the socket 28.
[0024] During operation of the cutting tool 10, it will be
appreciated that forces are generated at the axial forward end 42
of the insert 40 and that these forces are transferred through the
insert body, i.e. through the conical tip portion 46 and the
central portion 48 and through the mounting end portion 50 creating
a resulting stress on the base 56 of the insert 40. Advantageously,
the design of the first tapered segment 52 and, in particular, the
second tapered segment 54 results in less material being removed
from the socket 28 which in turn strengthens the surrounding steel
material of the head portion 18 of the cutting tool body 12 which
supports the insert 40 thus reducing the possibility of the insert
40 fracturing and/or reducing the possibility of steel fatigue in
the head portion 18 of the cutting tool body 12 so as to prevent
catastrophic failure of the cutting tool 10.
[0025] In addition, it will be appreciated that the base portion 36
of the socket 28 in association with the base 56 and the tapered
segments 52 and 54 are structured and arranged to allow additional
brazing material to flow and form around the insert 40 mounting end
portion 50 resulting in a stronger bonding between the insert 40
and the socket 28.
[0026] It will also be appreciated that the base 56 is structured
and arranged to provide added material to the insert 40 at a
location where maximum equivalent loading occurs during the impact
cycle of the cutting tool 10 and to provide longer lasting wear
protection to the cutting tool body 18 as the tool reaches its
final life cycle under abrasive cutting conditions.
[0027] Whereas particular aspects of this invention have been
described above for purposes of illustration, it will be evident to
those skilled in the art that numerous variations of the details of
the present invention may be made without departing from the
invention.
* * * * *