U.S. patent application number 13/424310 was filed with the patent office on 2012-09-27 for cutting tool.
This patent application is currently assigned to KENNAMETAL INC.. Invention is credited to Randall Walter Ojanen.
Application Number | 20120242136 13/424310 |
Document ID | / |
Family ID | 46831776 |
Filed Date | 2012-09-27 |
United States Patent
Application |
20120242136 |
Kind Code |
A1 |
Ojanen; Randall Walter |
September 27, 2012 |
Cutting Tool
Abstract
A cutting tool for use in impinging earth strata includes a
cutting tool body 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, wherein the cutting tool body contains a first socket at the
axial forward end thereof. The shank portion generally tapers in
the axial rearward direction. The cutting tool also includes a hard
cutting member affixed to the cutting tool body within the first
socket. The hard cutting member includes an axial forward end and
an axial rearward end. The hard cutting member also includes a
superhard axial forward portion of the axial forward end thereof,
wherein the superhard axial forward portion comprises a substrate
and a layer of superhard material adhered to the substrate.
Inventors: |
Ojanen; Randall Walter;
(Bristol, TN) |
Assignee: |
KENNAMETAL INC.
Latrobe
PA
|
Family ID: |
46831776 |
Appl. No.: |
13/424310 |
Filed: |
March 19, 2012 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61454661 |
Mar 21, 2011 |
|
|
|
Current U.S.
Class: |
299/105 ;
299/110 |
Current CPC
Class: |
E21C 35/183 20130101;
E21C 35/18 20130101 |
Class at
Publication: |
299/105 ;
299/110 |
International
Class: |
E21C 35/183 20060101
E21C035/183; E21C 35/18 20060101 E21C035/18 |
Claims
1. A cutting tool body with a central longitudinal axis, the
cutting tool body comprising: an axial forward end and an axial
rearward end; a head portion, a shank portion and a collar portion,
and the collar portion being mediate of and contiguous with the
head portion and the shank portion; wherein the shank portion has
an axial forward end and an axial rearward end and the shank
portion has a continuous taper in the axial rearward direction from
the axial forward end of the shank portion to the axial rearward
end of the shank portion.
2. The cutting tool body of claim 1, wherein a diameter of the
shank portion adjacent the axial forward end of the shank portion
is larger than a diameter of the shank portion adjacent the axial
rearward end.
3. The cutting tool body of claim 1, wherein a diameter of the
shank portion decreases linearly from adjacent the axial forward
end to the axial rearward end.
4. A cutting tool for use in impinging earth strata, the cutting
tool comprising: a cutting tool body 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 first
socket at the axial forward end thereof; wherein the shank portion
generally tapers in the axial rearward direction; and a hard
cutting member being affixed to the cutting tool body within the
first socket, the hard cutting member comprising: an axial forward
end and an axial rearward end; a superhard axial forward portion at
the axial forward end thereof; and a hard axial rearward portion
contiguous with and axially rearward of the superhard axial forward
portion and having a second socket for receiving the superhard
axial forward portion.
5. The cutting tool of claim 4, wherein the superhard axial forward
portion comprises a substrate and a layer of a superhard material
adhered to the substrate.
6. The cutting tool of claim 5, wherein the layer of superhard
material includes polycrystalline diamond (PCD) or polycrystalline
cubic boron nitride (PcBN).
7. The cutting tool of claim 5, wherein the substrate of the
superhard axial forward portion generally tapers in the axial
rearward direction.
8. The cutting tool of claim 7, wherein the second socket includes
sidewalls structured and arranged for receiving the tapered
substrate of the superhard axial forward portion.
9. The cutting tool of claim 8, wherein the sidewalls of the second
socket generally tapers in the axial rearward direction.
10. The cutting tool of claim 8, wherein the tapered substrate is
brazed to the tapered sidewalls of the second socket.
11. The cutting tool of claim 4, wherein the hard axial rearward
portion includes a cemented (cobalt) tungsten carbide material.
12. The cutting tool of claim 5, wherein the substrate of the
superhard axial forward portion includes a cemented (cobalt)
tungsten carbide material.
13. A cutting tool for use in impinging earth strata, the cutting
tool comprising: a cutting tool body 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 first
socket at the axial forward end thereof; and a hard cutting member
being affixed to the cutting tool body within the first socket, the
hard cutting member comprising: an axial forward end and an axial
rearward end; a superhard axial forward portion at the axial
forward end thereof, wherein the superhard axial forward portion
comprises a substrate and a layer of a superhard material adhered
to the substrate, and wherein the substrate of the superhard axial
forward portion generally tapers in the axial rearward direction;
and a hard axial rearward portion contiguous with and axially
rearward of the superhard axial forward portion and having a second
socket structured and arranged for receiving the superhard axial
forward portion.
14. The cutting tool of claim 13, wherein the layer of superhard
material includes polycrystalline diamond (PCD) or polycrystalline
cubic boron nitride (PcBN).
15. The cutting tool of claim 13, wherein the second socket
includes sidewalls structured and arranged for receiving the
tapered substrate of the superhard axial forward portion.
16. The cutting tool of claim 15, wherein the sidewalls of the
second socket generally taper in the axial rearward direction.
17. The cutting tool of claim 16, wherein the tapered substrate is
brazed to the tapered sidewalls of the second socket.
18. The cutting tool of claim 13, wherein the shank portion
generally tapers in the axial rearward direction.
19. The cutting tool of claim 13, wherein the hard axial rearward
portion includes a cemented (cobalt) tungsten carbide material.
20. The cutting tool of claim 13, wherein the substrate of the
superhard axial forward portion includes a cemented (cobalt)
tungsten carbide material.
21. The cutting tool body of claim 1, wherein the cutting tool body
is either rotatable or indexable.
22. The cutting tool of claim 4, wherein the cutting tool body is
either rotatable or indexable.
23. The cutting tool of claim 13, wherein the cutting tool body is
either rotatable or indexable.
24. A cutting tool for use in impinging earth strata, the cutting
tool comprising: a cutting tool body 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 first
socket at the axial forward end thereof; wherein the shank portion
generally tapers in the axial rearward direction; and a hard
cutting member being affixed to the cutting tool body within the
first socket.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/454,661 filed Mar. 21, 2011, which is hereby
fully incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The invention pertains generally to a cutting tool that is
useful for the impingement of a substrate or earth strata such as,
for example, asphaltic roadway material, coal deposits, mineral
formations and the like. More specifically, the invention pertains
to the aforementioned cutting tool wherein the cutting tool, which
may be either rotatable about its central longitudinal axis or an
indexable type cutting tool that is symmetrical about its central
longitudinal axis, carries a hard cutting member or a superhard
cutting member at the axially forward end thereof. The superhard
cutting member can be made from a superhard material (or includes a
portion there of made from a superhard material). Superhard
materials useful in the present invention include, without
limitation, materials such as polycrystalline diamond (PCD) or
polycrystalline cubic boron nitride (PCBN).
[0003] A cutting tool typically presents a generally elongate,
cylindrical geometry. The cutting tool comprises an elongate steel
cutting tool body, which has an axially forward end and an opposite
axially rearward end. A hard cutting member or a superhard cutting
member typically affixes to the axial forward end of the cutting
tool body. The cutting tool body typically carries an assembly or
means by which the cutting tool is rotatable carried by a
stationary block or holder on a drum. Alternatively, the cutting
tool can be indexable and fixed in place within the block or holder
on a drum.
[0004] Cutting tools can experience wear in a number of ways due to
the environment in which they operate and must be frequently
replaced. It would thus be highly desirable to provide an improved
cutting tool that experiences an increase in useful tool life as
compared to heretofore known cutting tools. It would also be highly
desirable to provide an improved cutting tool that may more easily
and quickly replaced once it has reached the end of its useful tool
life.
SUMMARY OF THE INVENTION
[0005] In accordance with an aspect of the invention, a cutting
tool body with a central longitudinal axis includes an axial
forward end, an axial rearward end, a head portion, a shank
portion, and a collar portion. The collar portion is mediate of and
contiguous with the head portion and the shank portion. The shank
portion has an axial forward end and an axial rearward end and the
shank portion has a continuous taper in the axial rearward
direction from the axial forward end of the shank portion to the
axial rearward end of the shank portion.
[0006] In accordance with another aspect of the invention, a
cutting tool for use in impinging earth strata includes a cutting
tool body 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,
wherein the cutting tool body contains a first socket at the axial
forward end thereof. The shank portion generally tapers in the
axial rearward direction. The cutting tool also includes a hard
cutting member affixed to the cutting tool body within the first
socket.
[0007] In accordance with an additional aspect of the invention, a
cutting tool for use in impinging earth strata includes a cutting
tool body 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,
wherein the cutting tool body contains a first socket at the axial
forward end thereof. The cutting tool also includes a hard cutting
member affixed to the cutting tool body within the first socket. A
hard cutting member includes an axial forward end and an axial
rearward end. The hard cutting member also includes a superhard
axial forward portion of the axial forward end thereof, wherein the
superhard axial forward portion comprises a substrate and a layer
of superhard material adhered to the substrate. The substrate of
the superhard axial forward portion generally tapers in the axial
rearward direction. The hard cutting member further includes a hard
axial rearward portion contiguous with and axially rearward of the
superhard axial forward portion and includes a second socket
structured and arranged for receiving the superhard axial forward
portion. In one aspect of the invention, the layer of superhard
material includes polycrystalline diamond (PCD) or polycrystalline
cubic boron nitride (PCBN).
[0008] In accordance with an additional aspect of the invention, a
cutting tool for use in impinging earth strata includes a cutting
tool body 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,
wherein the cutting tool body contains a first socket at the axial
forward end thereof. The cutting tool also includes a hard cutting
member affixed to the cutting tool body within the first
socket.
[0009] 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
[0010] FIG. 1 is a side, partially sectional view of a cutting
tool, in accordance with an aspect of the invention.
[0011] FIG. 2 is an enlarged, partially sectional, exploded view of
a hard cutting member of the rotatable cutting tool shown in FIG.
1, in accordance with an aspect of the invention.
DETAILED DESCRIPTION
[0012] Referring to the drawings, FIGS. 1-2 illustrate a cutting
tool of the invention, generally designated as 10. In one aspect,
the invention illustrated herein pertains generally to road planing
tools. However, one should appreciate that the invention has
application to other kinds of cutting tools useful in other kinds
of cutting operations. Exemplary operations 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 sizes
including larger-size pieces or chunks and smaller-sized pieces
including dust-like particles. 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.
[0013] 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.
[0014] 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. The shape can be as disclosed in U.S. Pat. No. 7,413,257.
Exemplary compositions of the steel for the cutting tool body 12
include without limitation those disclosed in the following
document: U.S. Pat. No. 4,886,710 to Greenfield, and U.S. Pat. No.
5,008,073 to Greenfield. The tool assembly is processed to enhance
performance as disclosed in U.S. Pat. No. 7,458,646. Elongate
cutting tool body 12 presents a generally cylindrical geometry, and
has an axial forward end 14 and an axial rearward end 16.
[0015] 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 20. The shank portion 20 includes an annular groove
24 adjacent the axial rearward end 16 for receiving a retainer ring
26, as is generally known. In one aspect, when installed into a
taper bore tool holder the retainer ring axially may retain the
tool and restrict free rotation, i.e. an indexable tool.
[0016] The head portion 18 contains a first socket 28 at the axial
forward end of the cutting tool body 12. The socket 28 includes a
frusto-conical portion 30 and a cylindrical portion 32. The socket
28 further includes a bottom surface 34. One should appreciate that
other geometries of a socket may be suitable for use with the
cutting tool 10 provided that the geometry of the hard cutting
member corresponds to that of the socket. Other geometries that
could be used are illustrated, for example, in U.S. Pat. Nos.
4,497,520, 4,981,328 and 5,837,071.
[0017] In accordance with an aspect of the invention, the shank
portion 20 of the cutting tool body 12 generally tapers in the
axial rearward direction. In other words, the shank portion 20 has
a diameter D1 at an axial forward end 15 adjacent to or near the
collar portion 22 that is larger than a diameter D2 at the axial
rearward end 16 of the shank portion 20. In one aspect, the
diameter may decrease linearly from the axial forward end of the
shank portion 20, i.e., adjacent to or near the collar portion 22,
toward the axial rearward end 16. In another aspect, the shank
portion 20 has a continuous taper from the axial forward end 15
(i.e. at or near where the shank portion has diameter D1) to the
axial rearward end 16 (i.e. at or near where the shank has diameter
D2).
[0018] In one aspect, the clearance between the tapered shank and
the tool block or holder is minimal as compared to standard cutting
tool assemblies and, in particular rotatable cutting tools. Known
rotatable cutting tools have generally had only cylindrically
shaped shanks which have a generous clearance between the shank and
tool holder to allow free rotation.
[0019] Cutting tool 10 further includes a hard cutting member,
generally designated as 40. The hard cutting member 40 may be
affixed by, for example, brazing within the first socket 28 at the
axial forward end 36 of the cutting tool body 12.
[0020] Referring particularly to FIG. 2, the hard cutting member 40
includes an axial forward end 42 and an axial rearward end 44. Hard
cutting member 40 further includes a hard axial rearward portion,
shown generally by bracket 46. The hard axial rearward portion 46
includes an axial forward face 48 which is contiguous with a
concave region 50. The hard axial rearward portion 46 includes a
generally frusto-conical portion 52 for cooperating with the
frusto-conical portion 30 of the socket 28 and a generally
cylindrical portion 54 for cooperating with the cylindrical portion
32 of the socket 28. As stated, the hard axial rearward portion 46
may be affixed to the socket 44 by brazing. Hard axial rearward
portion 46 may be made from, for example, a hard material such as,
for example, cemented (cobalt) tungsten carbide. Grades of cemented
(cobalt) tungsten carbide suitable for use herein include, for
example, those disclosed in U.S. Pat. No. 4,859,543 to Greenfield
and U.S. Pat. No. 6,197,084 to Smith.
[0021] Still referring to FIG. 2, the hard cutting member 40
further includes at the axial forward end thereof a superhard axial
forward portion, as shown by bracket 60. The superhard axial
forward portion 60 includes a substrate 62 which may be made from,
for example, a hard material such as, for example, cemented
(cobalt) tungsten carbide. Grades of cemented (cobalt) tungsten
carbide suitable for use herein include those disclosed in one or
more of the following patent documents, which pertain to a compact
of a superhard material and a carbide (or cemented carbide)
substrate: U.S. Pat. No. 4,063,909 to Mitchell, U.S. Pat. No.
4,604,106 to Hall et al., U.S. Pat. No. 4,694,918 to Hall, and U.S.
Pat. No. 4,811,801 to Salesky et al. One would expect that the
grades of cemented carbides disclosed in U.S. Pat. No. 4,859,543 to
Greenfield and U.S. Pat. No. 6,197,084 to Smith to also be suitable
for use as the substrate. The grade of cemented (cobalt) tungsten
carbide suitable for use as substrate 62 may or may not be the same
as the grade of cemented (cobalt) tungsten carbide suitable for use
as the hard axial rearward portion 46. The specific application for
the rotatable cutting tool may dictate the specific grades of
cemented (cobalt) tungsten carbide suitable for use therein. In
other words, the composition of the substrate 62 may or may not be
the same as the composition of the hard axial rearward portion
46.
[0022] The superhard axial forward portion 60 further includes a
layer of a superhard material 64 adhered to the substrate 62. The
layer of superhard material 64 may include, for example,
polycrystalline diamond (PCD) or polycrystalline cubic boron
nitride (PCBN). The layer of superhard material 64 may have a
generally constant thickness and can be applied to the substrate 62
by any one of the number of known techniques wherein the superhard
material is bonded to the surface of the substrate 62. In addition,
the layer of superhard material 64 is shown as having a generally
hemispherical shape, but it will be appreciated that it may have
other shapes and configurations as desired or needed for particular
cutting operations.
[0023] One can apply the layer of superhard material 64, e.g.
polycrystalline diamond, to the substrate 62 by any one of a number
of techniques wherein the layer of superhard material 64 is bonded
to the surface of the substrate 62. The following patent documents
disclose exemplary compositions of polycrystalline diamond as well
as exemplary techniques to apply a layer of polycrystalline diamond
to the surface of a substrate: U.S. Pat. No. 4,063,909 to Mitchell,
U.S. Pat. No. 4,604,106 to Hall et al., U.S. Pat. No. 4,694,918 to
Hall, and U.S. Pat. No. 4,811,801 to Salesky et al.
[0024] In accordance with another aspect of the invention,
sidewalls 66 of the substrate 62 generally taper in the axial
rearward direction. This tapered braze joint shape provides a high
strength and better reliability than the simple butt joint geometry
typically used by known cutting tools as shown, for example, in
U.S. Pat. Nos. 6,051,079 and 7,464,993. The tapered sidewalls 66 of
the substrate 62 may be formed by, for example, a grinding process
to obtain the generally desired tapered, conical shaped substrate
62.
[0025] In another aspect of the invention, the axial forward end 48
of the hard axial rearward portion 46 includes a second socket 56
formed therein. The second socket 56 is structured and arranged for
receiving the superhard axial forward portion 60. More
particularly, the second socket 56 includes conical sidewalls 68
structured and arranged for receiving the tapered sidewalls 66 of
the superhard axial forward portion 60. In one aspect, the
sidewalls 68 of the second socket 56 generally taper in the axial
rearward direction similar to the tapering of the sidewalls 66 of
the substrate 62.
[0026] In another aspect of the invention, the sidewalls 68 of the
second socket 56 may be formed at an angle X1, which in one
exemplary embodiment may be about 30.degree.. The angle X1 may
range from about 10.degree. to about 60.degree.. These are all
angles that can be economically pressed and sintered with
conventional carbide processing technology. Similarly, the
sidewalls 66 of the substrate 62 may be formed at an angle X2,
which in one exemplary embodiment may be about 30.degree. for
corresponding to the tapered sidewalls 68 of the second socket 56.
In one aspect, the angle X2 may be in the range of about 1.degree.
to about 2.degree. larger than the angle X1.
[0027] As described, the superhard axial forward portion 60 is
received in the second socket 56 of the hard axial rearward portion
46. In particular, the superhard axial forward portion 60 is
affixed to the hard axial rearward portion 46 by brazing the
sidewalls 66 of the substrate 62 to the sidewalls 68 of the second
socket 56. Although not required, brazing may also be provided
between a bottom surface 70 of the substrate 62 and a bottom area
72 of the second socket 56. The tapered insert brazing geometry
provides more surface area to bond the superhard axial forward
portion 60 to the hard axial rearward portion 46 allowing smaller
diameter cutting inserts to be used as compared to the known butt
brazed cutting inserts for cutting tools. In one aspect, smaller
cutting insert diameters will enable higher machine speeds. It will
be appreciated that other methods of attachment besides brazing,
e.g. gluing and other attachment methods known in the art, may be
used with the invention.
[0028] 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 as defined in the appended claims. For example, in one
aspect the tapered shank aspect, e.g. shank 20, may be used with
various types of cutting tools having various types of cutting
inserts, e.g. superhard cutting inserts (e.g., PCD or PCBN) or hard
cutting inserts (e.g, carbide cutting inserts) and the like. Shanks
that are not tapered can also be used in association with aspect of
the invention. In another aspect, various types of cutting inserts
having various shapes and configurations may be used wherein the
sidewalls of the insert are brazed to the sidewalls of the socket
in which it is received. In addition, the axial forward end of the
cutting insert can have various shapes and configurations such as,
for example, hemispherical, frusto-conical, conical or other known
shapes for cutting inserts as desired. In another aspect, either
superhard cutting inserts (e.g., PCD or PCBN) or hard cutting
inserts (e.g, carbide cutting inserts) or combinations thereof may
be used with the invention.
* * * * *