U.S. patent application number 13/089744 was filed with the patent office on 2011-10-27 for method and apparatus for a cutting tool.
This patent application is currently assigned to IRWIN INDUSTRIAL TOOL COMPANY. Invention is credited to Thomas M. Chervenak, David P. Engvall, Mark B. Latronico.
Application Number | 20110259149 13/089744 |
Document ID | / |
Family ID | 44814641 |
Filed Date | 2011-10-27 |
United States Patent
Application |
20110259149 |
Kind Code |
A1 |
Chervenak; Thomas M. ; et
al. |
October 27, 2011 |
METHOD AND APPARATUS FOR A CUTTING TOOL
Abstract
A method of making a cutting tool comprises providing a lever
with a jaw having a cutting edge and a body arranged such that the
cutting edge is offset from the body; providing a rotary cutting
tool with an edge profile that may be complex and/or non-planar to
form a complementary edge profile geometry on the cutting edge by
moving the edge profile geometry of the rotary cutting tool along
the length of the cutting edge.
Inventors: |
Chervenak; Thomas M.;
(Stanley, NC) ; Engvall; David P.; (Stanley,
NC) ; Latronico; Mark B.; (Charlotte, NC) |
Assignee: |
IRWIN INDUSTRIAL TOOL
COMPANY
Huntersville
NC
|
Family ID: |
44814641 |
Appl. No.: |
13/089744 |
Filed: |
April 19, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61328505 |
Apr 27, 2010 |
|
|
|
Current U.S.
Class: |
76/101.1 |
Current CPC
Class: |
B24B 3/60 20130101; B23P
15/40 20130101; B26B 17/00 20130101; B23P 15/28 20130101 |
Class at
Publication: |
76/101.1 |
International
Class: |
B21K 21/00 20060101
B21K021/00 |
Claims
1. A method of making a cutting tool comprising: providing a lever
comprising a jaw having a cutting edge and a body arranged such
that the cutting edge is offset from the body; providing a rotary
cutting tool with an edge profile geometry; forming a complementary
edge profile geometry on the cutting edge by moving the edge
profile geometry of the rotary cutting tool along the length of the
cutting edge.
2. The method of claim 1 wherein the step of forming is done when
the cutting edge is in a soft state.
3. The method of claim 1 wherein the step of forming is done when
the cutting edge is in a hardened metal.
4. The method of claim 1 wherein the lever arm of the tool is
fixtured in a predetermined position.
5. The method of claim 1 where the rotary cutting tool is fed in a
straight path along the cutting edge.
6. The method of claim 1 where the rotary cutting tool traverses
the entire cutting edge.
7. The method of claim 1 where the rotary cutting tool traverses
the cutting edge without contacting the body.
8. The method of claim 1 further comprising providing a plurality
of levers each having a cutting edge, fixturing the plurality of
levers such that each cutting edge of the plurality of levers are
aligned, moving the rotary cutting tool along a linear path along
the cutting edges.
9. The method of claim 1 wherein the rotary cutting tool is a
grinding wheel.
10. The method of claim 1 wherein the rotary cutting tool is a form
cutter.
12. A method of making a cutting tool comprising: providing a lever
comprising a jaw having a cutting edge and a body arranged such
that the cutting edge is offset from the body; providing a rotary
cutting tool with a first edge profile and a second edge profile;
forming a first portion of complementary edge profile geometry on
the cutting edge by moving the first edge profile of the rotary
cutting tool along the length of a first side of the cutting edge
and forming a second portion of complementary edge profile geometry
on the cutting edge by moving the second edge profile of the rotary
cutting tool along the length of a second side of the cutting
edge.
13. The method of claim 12 wherein the step of forming is done when
the cutting edge is in a soft state.
14. The method of claim 12 wherein the step of forming is done when
the cutting edge is in a hardened metal.
15. The method of claim 12 wherein the lever arm of the tool is
fixtured in a predetermined position.
16. The method of claim 12 where the rotary cutting tool is fed in
a straight path along the cutting edge.
17. The method of claim 12 where the rotary cutting tool traverses
the entire cutting edge.
18. The method of claim 12 where the rotary cutting tool traverses
the cutting edge without contacting the body.
19. The method of claim 12 further comprising providing a plurality
of levers each having a cutting edge, fixturing the plurality of
levers such that each cutting edge of the plurality of levers are
aligned, moving the rotary cutting tool along a linear path along
the cutting edges.
20. The method of claim 1 wherein the rotary cutting tool is a
grinding wheel or a form cutter.
Description
[0001] This application claims benefit of priority under 35 U.S.C.
.sctn.119(e) to the filing date of to U.S. Provisional Application
No. 61/328,505, as filed on Apr. 27, 2010, which is incorporated
herein by reference in its entirety.
BACKGROUND
[0002] The most common process for forming a cutting edge on a
diagonal pliers is by first machining the tool when the metal is in
a "soft" state using an end mill or similar cutter. One problem
with this process is that it limits the geometry on the cutting
edge to simple angular shapes that are limited to flat planar
surfaces. The process may also lead to variations in the finished
product because each cutting edge is formed by two independent
machining steps determined by the depth or trajectory of each cut.
Because of these variations, the process may further require hand
finishing of the hardened cutting edges to bring the edges into
proper final alignment. CNC machining of the cutting edges is an
alternative to standard machining, but can be costly and/or slow in
a production setting. CNC is also limited to only cutting the edges
in the soft state of the pliers.
SUMMARY OF THE INVENTION
[0003] A method of making a cutting tool comprises providing a
lever with a jaw having a cutting edge and a body arranged such
that the cutting edge is offset from the body; providing a rotary
cutting tool with an edge profile that may be planar and/or
non-planar to form a complementary edge profile geometry on the
cutting edge by moving the edge profile geometry of the rotary
cutting tool along the length of the cutting edge.
[0004] Another method of making a cutting tool comprises providing
a lever with a jaw having a cutting edge that may comprise complex,
planar and/or non-planar shapes and a body arranged such that the
cutting edge is offset from the body; providing a rotary cutting
tool with a first edge profile and a second edge profile; and
forming a first portion of complementary edge profile geometry on
the cutting edge by moving the first edge profile of the rotary
cutting tool along the length of a first side of the cutting edge
and forming a second portion of complementary edge profile geometry
on the cutting edge by moving the second edge profile of the rotary
cutting tool along the length of a second side of the cutting
edge.
[0005] The step of forming may be done when the cutting edge is in
a soft state or when the cutting edge is in a hardened metal. The
lever arm of the tool may be fixtured in a predetermined position.
The rotary cutting tool may be fed in a straight path along the
cutting edge. The rotary cutting tool may traverse the entire
cutting edge. The rotary cutting tool may traverse the cutting edge
without contacting the body. A plurality of levers each having a
cutting edge may be fixtured such that all of the cutting edges are
aligned and the rotary cutting tool is moved along a linear path
along the cutting edges. The rotary cutting tool may be a grinding
wheel or a form cutter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a perspective view of an embodiment of an example
cutting tool on which the methods of the invention may be used.
[0007] FIG. 2 is an end view of one lever of the tool of FIG.
1.
[0008] FIG. 3 is an end view of the other lever of the tool of FIG.
1.
[0009] FIG. 4 is a perspective view of a lever fixtured and engaged
by a rotary cutting tool according to one embodiment of the method
of the invention.
[0010] FIG. 5 is an end view of a lever fixtured and engaged by a
rotary cutting tool according to one embodiment of the method of
the invention.
[0011] FIG. 6 is a plan view of a lever showing the engagement of a
rotary cutting tool with a cutting edge according to one embodiment
of the method of the invention.
[0012] FIG. 7 is an end view showing a lever as designed according
to one embodiment of the invention.
[0013] FIGS. 8a and 8b are plan views comparing the lever of FIG. 3
and the lever of FIG. 7.
[0014] FIG. 9 is a plan view showing the engagement of a rotary
cutting tool with a plurality of cutting edges according to another
embodiment of the method of the invention.
[0015] FIG. 10 is a perspective view of a lever fixtured and
engaged by a rotary cutting tool according to yet another
embodiment of the method of the invention.
[0016] FIG. 11 is an end view of a lever fixtured and engaged by a
rotary cutting tool according to the embodiment of FIG. 10.
[0017] FIG. 12 is a detailed end view of the cutting edge engaged
by a rotary cutting tool having a different profile.
[0018] FIG. 13 is a detailed view of FIG. 11 showing the engagement
of the rotary cutting tool with the cutting edge of the lever.
[0019] FIG. 14 is a detailed view similar to FIG. 13.
[0020] FIG. 15 is an end view of a lever fixtured and engaged by a
rotary cutting tool according to the embodiment of the method of
the invention of FIG. 13.
DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0021] A grinding or machining technique is used to create the
finished geometry on the cutting edge of a tool. Grinding can be
done with the pliers in either in a soft state or on hardened metal
such as after induction hardening or other hardening operation.
Machining is typically performed before hardening with the edge
being hardened after the machining operation. The grinding
operation is performed using a rotary grinding wheel that uses
abrasion to remove material to form the edge. The machining
operation is performed using a rotary form cutter having sharp
cutting edges that cut the material to form the edge. As used
herein the term "rotary cutting tool" means both a grinding wheel
and a form cutter and the term "rotary cutting operation" means
both an abrasive grinding operation and a form milling
operation.
[0022] One lever arm of the tool is fixtured in a predetermined
position before it is assembled to the other lever arm of the tool.
A rotary cutting tool is fed in a straight path along the cutting
edge so that the geometry of the rotary cutting tool forms the
shape of the tool's cutting edge. This is advantageous because a
variety of different and complex shapes may be provided to create
specialized edge shapes such as parabolic, hollow ground, or
compound forms that are not obtainable using known techniques and
that may be used for cutting materials of differing hardness and
diameter.
[0023] FIGS. 1, 2 and 3 show a diagonal cutting pliers tool. A
first lever 2 is pivotably attached to a second lever 4 at pivot 6.
The first lever 2 has a handle 10 at one end and a jaw 8 at the
opposite end with a body 9 disposed between the handle 10 and jaw
8. The second lever 4 has a handle 12 at one end and a jaw 14 at
the opposite end with a body 13 disposed between the handle 12 and
jaw 14. The pivot 6 passes through apertures 20 formed in bodies 9
and 13. A first cutting edge 16 is formed on the first jaw 8 and a
second cutting edge 18 is formed on the second jaw 14. The cutting
edges 16 and 18 are aligned to cut an article when the levers 2 and
4 bring the jaws 8 and 14 together. Cutting tools such as the one
described with reference to FIG. 1 may have a variety of jaw
shapes, sizes, handle shapes, pivot arrangements or the like and
may be used in a wide variety of applications. While a specific
embodiment of a cutting tool is shown the method of the invention
has applicability to any tool where the formation of a cutting edge
using the method described herein may be advantageous.
[0024] FIGS. 2 and 3 show end views of the jaws 8 and 14 of a
traditional pliers. In a traditional pliers one jaw 14 is typically
arranged such that the cutting edge 18 is offset from the body 13
and handle 12 as shown in FIG. 2. The cutting plane is defined
herein as a plane extending along the cutting edge and that extends
through the two cutting edges of the tool (e.g. cutting edges 16
and 18) during articulation of the tool. The edge 18 is offset such
that a cutting plane L-L extending through the cutting edge 18 does
not interfere with the body 13 or handle 12. The other jaw 8 is
typically arranged with the cutting edge 16 disposed within the
width of the body 9 as shown in FIG. 3. In such an arrangement a
cutting plane A-A extending through cutting edge 16 and
perpendicular to the axis of rotation of the lever 4 intersects the
body 9 and/or handle 10 of the lever 2.
[0025] Referring to FIG. 2 because the cutting plane L-L through
the offset cutting edge 18 on jaw 14 does not interfere with the
rest of lever 4, a rotary cutting tool is able to pass along edge
18 and clear the rest of the lever such that the lever does not
contact or interfere with the rotary cutting tool as it passes
along cutting plane L-L for the full extent of edge 18. By
positioning the peripheral edge of a rotary cutting tool on the
cutting edge and moving the rotary cutting tool along the cutting
plane L-L and along the length of the cutting edge 18, the profile
of the rotary cutting tool will create the final shape of the
cutting edge 18. This method is advantageous because a rotary
cutting tool can be dressed to have a wide range and variety of
shapes including complex shapes that can be easily formed into edge
18. Further, a rotary cutting tool moved along the length of the
cutting edge attains better precision when compared to other
methods of finishing a cutting edge.
[0026] FIG. 4 shows an isometric view of lever 4 fixtured with a
grinding wheel 32 passing over the cutting edge 18. FIG. 10 shows a
similar isometric view except that the grinding wheel 32 is
replaced by a form cutter 132. Like reference numerals are used to
indentify like components in the various views. A fixture 30 fixes
the lever 4 in a known position relative to the grinding wheel 32.
The fixture 30 may for example have a pin 34 that closely engages
aperture 20 (used to receive pivot 6 in the finished tool) and
surfaces 36 that closely engage surfaces of the lever 4 to properly
position the lever 4 relative to the grinding wheel 32. Typically,
a clamp (not shown) clamps the lever in position such that it does
not move relative to the fixture 30 during the rotary cutting
operation. Any suitable fixture may be used that fixes the lever in
a known position relative to the rotary cutting tool.
[0027] FIGS. 5, 11 and 12 show end views down the line of the
cutting edge 18 with grinding wheel 32 and form cutter 132 engaged,
with edge 18. The cutting tools are provided with profiles P, P'
and P''. The profile P of the edge of the grinding wheel 32 and the
profiles P' and P'' of the teeth 132a of form cutter 132 can be
made to have a variety of shapes, including complex shapes,
non-planar shapes and shapes having a combination of planar and
non-planar surfaces, where the rotary cutting tool 32, 132 creates
a complimentary shape on the cutting edge 18. Profiles P and P'
show a complex cutting edge shape where all of the faces of the
cutting edge are planar. Profile P'' shows a cutting edge 18 with a
rounded surface at the tip. The profiles and complementary cutting
edges may have a variety of complex shapes including planar and
non-planar surfaces.
[0028] The rotary cutting tool 32, 132 is moved along the length of
edge 18 such that the rotary cutting tool 32, 132 forms the shape
of the edge 18 but does not interfere with the rest of the tool.
The rotary cutting tool 32, 132 is arranged such that the
rotational axis a-a of the rotary cutting tool 32, 132 is normal to
the cutting plane of the edge. FIG. 6 shows a top view of the
cutting path CP of the rotary cutting tool 32, 132 relative to the
lever arm. As can be seen from the figures because cutting plane
L-L is offset from the rest of lever arm 4, the rotary cutting tool
32, 132 is able to traverse the entire length of the cutting edge
18 in a straight line without contacting any other part of the
lever.
[0029] This method can be used on any cutting tool where the rotary
cutting tool 32, 132 is able to traverse the cutting edge without
interfering with or contacting the remainder of the tool. Referring
to FIGS. 2, 3, 11 and 12 in a traditional tool the method of the
invention may be used with jaw 14, however, it cannot be used with
jaw 8 because the cutting plane A-A through cutting edge 16 extends
into the body 9 of lever 2 as illustrated in FIG. 3. If the rotary
cutting tool is passed over edge 16 along plane A-A it would strike
body 9. Thus, in a traditional pliers the manufacturing process of
the invention may be used to create one cutting edge while the
other cutting edge may be made with existing technology.
[0030] To use the grinding method of the invention on both jaws of
the tool, both jaws may be designed with the cutting edge being
offset outside of the width of the body of the lever. FIG. 7 shows
an end view of a jaw and lever having the cutting edge 28 offset
from the body of the lever to allow clearance for the rotary
cutting tool along cutting plane P-P. The lever of FIG. 7 is used
in place of the lever 2 and jaw 8 (FIG. 3) in one embodiment of the
tool. FIGS. 8a and 8b are top views showing a traditional lever
(FIG. 8a) and the offset edge lever of the invention (FIG. 8b). In
the offset edge design of FIG. 8b the lever 4 comprises a handle 10
connected to jaw 24 by body 9. Jaw 24 comprises a cutting edge 28
that is positioned such that a cutting plane P-P that extends
through edge 28 is offset from the body 9 such that a rotary
cutting tool 32, 132 is able to traverse the entire length of the
cutting edge 28 without contacting any other part of the lever. The
use of offset edges on both jaws of the tool creates a visual
difference in the look of the tool over traditional jaws and may
result in a cutting edge alignment with a slightly different angled
face than a traditional tool, but the overall operation of the
pliers is the same as traditional pliers.
[0031] Another benefit of using rotary cutting tool 32, 132 as
described herein is that multiple levers can be fixtured in
alignment such that one rotary cutting tool 32, 132 can follow a
linear path along the aligned cutting edges of multiple tools.
Referring to FIG. 9, three levers 2 are shown as mounted in
fixtures (not shown) with the cutting edges 18 aligned on a common
line D. A single rotary cutting tool 32, 132 follows a linear path
along line D to form the cutting edges 18 on a plurality of tools
in one operation. This method can be used to increase production
rates and lower manufacturing costs for high volume production.
[0032] Referring to FIGS. 13, 14 and 15 an alternate embodiment of
the method of forming a cutting edge is shown. The method is
illustrated where the rotary cutting tool is a form cutter 132
although the method may also use a grinding wheel. Unlike the
rotary cutting tool previously described, the profile P'' formed on
the cutting tips of the rotary cutting tool is formed with two half
profiles rather than the full geometry profile as previously
described. Referring to FIG. 14 cutting profile P'' has a first
half profile P1 formed on one side of the rotary cutting tool and a
second half profile P2 formed on the other side of the rotary
cutting tool. The profiles P1 and P2 are arranged such that one
profile P1 is brought into contact with one side of the cutting
edge 18 to form half of the cutting edge in a first pass of the
rotary cutting tool and the other profile P2 is brought into
contact with the other side of the cutting edge 18 to form the
other half of the cutting edge in a second pass of the rotary
cutting tool.
[0033] To form the cutting edge 18 a rotary cutting tool as
described above is provided. A first cutting profile P1 is disposed
along one side of the rotary cutting tool and the rotary cutting
tool is aligned such that the rotary cutting tool is passed over
the cutting edge 18 in a linear path, as previously described, with
the first cutting profile P1 forming one half of the cutting edge
as shown in FIGS. 13 and 14. The rotary cutting tool is then
indexed transversely to the cutting edge the approximate width of
the cutting edge such that the second cutting profile P2 is
disposed along the other side of the cutting edge 18. The rotary
cutting tool is aligned such that the rotary cutting tool is passed
over the cutting edge 18 in a linear path, as previously described,
with the second cutting profile P2 forming the second half of the
cutting edge as shown in FIG. 15. While the invention has been
described with each cutting profile P1, P2 forming half of the
cutting edge, each profile may form more or less than one-half of
the cutting edge provided the plural cutting profiles form a
complete cutting edge.
[0034] While embodiments of the invention are disclosed herein,
various changes and modifications can be made without departing
from the spirit and scope of the invention as set forth in the
claims. One of ordinary skill in the art will recognize that the
invention has other applications in other environments. Many
embodiments are possible. The following claims are in no way
intended to limit the scope of the invention to the specific
embodiments described above.
* * * * *