U.S. patent application number 17/571927 was filed with the patent office on 2022-04-28 for saw blade and system and method for manufacturing a saw blade.
The applicant listed for this patent is MILWAUKEE ELECTRIC TOOL CORPORATION. Invention is credited to James P. Horne, JR..
Application Number | 20220126383 17/571927 |
Document ID | / |
Family ID | |
Filed Date | 2022-04-28 |
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United States Patent
Application |
20220126383 |
Kind Code |
A1 |
Horne, JR.; James P. |
April 28, 2022 |
SAW BLADE AND SYSTEM AND METHOD FOR MANUFACTURING A SAW BLADE
Abstract
A saw blade includes a body having a thickness, an attachment
portion formed on the body, and a plurality of cutting teeth formed
on the body. The attachment portion is configured to connect the
saw blade to a power tool. Each cutting tooth of the plurality of
cutting teeth includes a tip defining a plane that extends along
the thickness of the body, a rake face extending from the tip, and
a relief face extending from the tip opposite the rake face. A
first cutting tooth of the plurality of cutting teeth is set in a
first direction relative to the body. A second cutting tooth of the
plurality of cutting teeth is set in a second direction opposite
the first direction relative to the body. The planes defined by the
tips of the first and second cutting teeth are generally
parallel.
Inventors: |
Horne, JR.; James P.;
(Greenwood, MS) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MILWAUKEE ELECTRIC TOOL CORPORATION |
Brookfield |
WI |
US |
|
|
Appl. No.: |
17/571927 |
Filed: |
January 10, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15497426 |
Apr 26, 2017 |
11219959 |
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17571927 |
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14215179 |
Mar 17, 2014 |
9662725 |
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15497426 |
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61787755 |
Mar 15, 2013 |
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International
Class: |
B23D 61/12 20060101
B23D061/12; B23D 61/02 20060101 B23D061/02; B23D 65/02 20060101
B23D065/02 |
Claims
1. A saw blade comprising: a body having a thickness; an attachment
portion formed on the body, the attachment portion configured to
connect the saw blade to a power tool; and a plurality of cutting
teeth formed on the body, each cutting tooth including a tip
defining a plane that extends along the thickness of the body, a
rake face extending from the tip, and a relief face extending from
the tip opposite the rake face; wherein a first cutting tooth of
the plurality of cutting teeth is set in a first direction relative
to the body, wherein a second cutting tooth of the plurality of
cutting teeth is set in a second direction opposite the first
direction relative to the body, and wherein the planes defined by
the tips of the first and second cutting teeth are generally
parallel.
2. The saw blade of claim 1, wherein the first cutting tooth and
the second cutting tooth are generally the same height so that the
planes defined by the tips of the first and second cutting teeth
are generally coplanar.
3. The saw blade of claim 1, wherein a third cutting tooth of the
plurality of cutting teeth is unset relative to the body, and
wherein the plane defined by the tip of the third cutting tooth is
generally parallel to the planes defined by the tips of the first
and second cutting teeth.
4. The saw blade of claim 3, wherein the first cutting tooth, the
second cutting tooth, and the third cutting tooth are generally the
same height so that the planes defined by the tips of the first,
second, and third cutting teeth are generally coplanar.
5. The saw blade of claim 1, wherein the first cutting tooth has a
first set magnitude, wherein the second cutting tooth has a second
set magnitude, and wherein the first and second set magnitudes are
generally equal.
6. The saw blade of claim 1, wherein the first cutting tooth and
the second cutting tooth are generally the same shape and size.
7. The saw blade of claim 1, wherein the attachment portion
includes a tang and an aperture.
8. The saw blade of claim 1, wherein the planes defined by the tips
of the first cutting tool and the second cutting tool are angled
relative to the thickness of the body.
9. The saw blade of claim 1, wherein the planes defined by the tips
of the first cutting tool and the second cutting tool are generally
parallel with the thickness of the body.
10. The saw blade of claim 1, wherein the first cutting tooth and
the second cutting tooth are different heights.
11. A saw blade comprising: a body having a thickness; a first
cutting tooth formed on the body and including a tip defining a
plane that extends parallel to the thickness of the body, the first
cutting tooth set in a first direction relative to the body; and a
second cutting tooth formed on the body and including a tip
defining a plane that extends parallel to the thickness of the
body, the second cutting tooth set in a second direction relative
to the body that is opposite the first direction; wherein the
planes defined by the tips of the first and second cutting teeth
are generally coplanar.
12. The saw blade of claim 11, further comprising a third cutting
tooth formed on the body and including a tip defining a plane that
extends along the thickness of the body, wherein the third cutting
tooth is unset relative to the body, and wherein the plane defined
by the tip of the third cutting tooth is generally parallel to the
planes defined by the tips of the first and second cutting
teeth.
13. The saw blade of claim 12, wherein the first cutting tooth, the
second cutting tooth, and the third cutting tooth are generally the
same height so that the planes defined by the tips of the first,
second, and third cutting teeth are generally coplanar.
14. The saw blade of claim 11, wherein the first cutting tooth has
a first set magnitude, wherein the second cutting tooth has a
second set magnitude, and wherein the first and second set
magnitudes are generally equal.
15. The saw blade of claim 11, wherein the first cutting tooth and
the second cutting tooth are generally the same shape and size.
16. The saw blade of claim 11, wherein the first cutting tooth and
the second cutting tooth each include a rake face extending from
the tip, and a relief face extending from the tip opposite the rake
face.
17. A saw blade comprising: a body having a thickness; an
attachment portion formed on the body, the attachment portion
configured to connect the saw blade to a power tool; and a
plurality of cutting teeth formed on the body, the plurality of
cutting teeth including a first cutting tooth having a first tip
defining a first plane that extends along the thickness of the
body, a first rake face extending from the first tip, and a first
relief face extending from the first tip opposite the first rake
face, the first cutting tooth being set in a first direction
relative to the body, a second cutting tooth including a second tip
defining a second plane that extends along the thickness of the
body, a second rake face extending from the second tip, and a
second relief face extending from the second tip opposite the
second rake face, the second cutting tooth being set in a second
direction opposite the first direction relative to the body, and a
third cutting tooth including a third tip defining a third plane
that extends along the thickness of the body, a third rake face
extending from the third tip, and a third relief face extending
from the third tip opposite the third rake face, the third cutting
tooth being unset relative to the body, wherein the first cutting
tooth, the second cutting tooth, and the third cutting tooth are
generally the same shape and size, and wherein the first plane, the
second plane, and the third plane are parallel.
18. The saw blade of claim 17, wherein the first plane, the second
plane, and the third plane are coplanar.
19. The saw blade of claim 17, wherein the first cutting tooth has
a first set magnitude, wherein the second cutting tooth has a
second set magnitude, and wherein the first and second set
magnitudes are generally equal.
20. The saw blade of claim 17, further comprising a cutting tip
formed on the body opposite from the attachment portion.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 15/497,426, filed Apr. 26, 2017, now U.S. Pat. No.
11,219,959, which is a divisional of U.S. patent application Ser.
No. 14/215,179, filed Mar. 17, 2014, now U.S. Pat. No. 9,662,725,
which claims priority to U.S. Provisional Patent Application No.
61/787,755, filed Mar. 15, 2013, the entire contents of all of
which are incorporated by reference herein.
BACKGROUND
[0002] The present invention relates to saw blades and to systems
and methods for manufacturing saw blades.
[0003] Traditionally, saw blades, such as reciprocating saw blades,
jigsaw blades, and hole saws, are produced by first forming cutting
teeth on coil stock and then setting the cutting teeth in a desired
pattern. Setting is the process of bending the cutting teeth in
opposing directions to provide kerf or clearance for a body of the
saw blade during cutting. Setting typically involves striking each
cutting tooth with an insert that is made from a harder material
than the cutting tooth itself.
[0004] During setting, the hard insert initially comes into contact
with a tip of the cutting tooth where a surface area of the cutting
tooth is smallest. The insert presses against the cutting tooth
until enough surface area is contacted to generate a force higher
than the yield strength of the saw blade body at a bend point near
a root of the cutting tooth. This process, however, may create
undesirable deformations along a side face of the saw blade body
and at the tip of the cutting tooth.
SUMMARY
[0005] In one embodiment, the invention provides a method of
manufacturing a saw blade. The method includes providing a coil
stock, setting a first portion of the coil stock in a first
direction, setting a second portion of the coil stock in a second
direction opposite the first direction, and forming a plurality of
cutting teeth in the first portion and the second portion of the
coil stock after the first and second portions are set.
[0006] In another embodiment, the invention provides a saw blade
including a body having a thickness and an attachment portion
formed on the body. The attachment portion is configured to connect
the saw blade to a power tool. The saw blade also includes a
plurality of cutting teeth formed on the body. Each cutting tooth
includes a tip defining a plane that extends along the thickness of
the body, a rake face extending from the tip, and a relief face
extending from the tip opposite the rake face. A first cutting
tooth of the plurality of cutting teeth is set in a first direction
relative to the body, and a second cutting tooth of the plurality
of cutting teeth is set in a second direction opposite the first
direction relative to the body. The planes defined by the tips of
the first and second cutting teeth are generally parallel.
[0007] In yet another embodiment, the invention provides a saw
blade blank including a body having an edge and an attachment
portion formed on the body. The attachment portion is configured to
connect to a power tool. A first portion of the edge is set in a
first direction relative to the body, and a second portion of the
edge is set in a second direction opposite the first direction
relative to the body. No cutting teeth are formed on the edge of
the body.
[0008] Other aspects of the invention will become apparent by
consideration of the detailed description and accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a flowchart depicting a conventional method of
manufacturing a saw blade.
[0010] FIG. 2 is a flowchart depicting a method of manufacturing a
saw blade according to one embodiment of the present invention.
[0011] FIG. 3 illustrates a machine for setting the saw blade.
[0012] FIG. 4 is an enlarged view of a portion of the machine shown
in FIG. 3.
[0013] FIG. 5A is a perspective view of a saw blade blank having
portions set in opposite directions, but no cutting teeth.
[0014] FIG. 5B is a perspective view of another saw blade blank
having portions set in opposite directions, but no cutting
teeth.
[0015] FIG. 6 is a top view of a first saw blade manufactured by
the method of FIG. 1 and a second saw blade manufactured by the
method of FIG. 2.
[0016] FIG. 7 is a side view of the first and second saw blades of
FIG. 6.
[0017] FIG. 8 is an end perspective view of the first and second
saw blades of FIG. 6.
[0018] Before any embodiments of the invention are explained in
detail, it is to be understood that the invention is not limited in
its application to the details of construction and the arrangement
of components set forth in the following description or illustrated
in the following drawings. The invention is capable of other
embodiments and of being practiced or of being carried out in
various ways.
DETAILED DESCRIPTION
[0019] FIG. 1 illustrates an example of a conventional process of
manufacturing a saw blade. As depicted in the flowchart, incoming
coil stock is first straightened and blanked into a desired blade
shape. The blank is then placed into a grinder to form cutting
teeth on the blank. The illustrated process utilizes two grinders
to form cutting teeth on two blanks simultaneously. After grinding,
the saw blade is cleaned or washed to remove grinding debris and
coolant residue. Once cleaned, the saw blade is loaded into a
setting machine to set the cutting teeth to a desired
specification. The illustrated process utilizes six setting
machines, or stations, to keep up with the number of saw blades
being output from the grinders.
[0020] FIG. 2 illustrates a process or method of manufacturing a
saw blade according to the present invention. In general, the
illustrated method includes a step 10 to straighten coil stock, a
step 14 to form a blade blank from the coil stock, a step 18 to
form cutting teeth on the blade blank, a step 22 to wash the saw
blade, and a step 26 to load the saw blade into a heat tray. The
process of FIG. 2 is different from the process of FIG. 1 in that
setting occurs at step 14 before the cutting teeth are formed at
step 18. In some embodiments, the process may omit one or more of
the steps 10, 22, 26, yet still fall within the scope of the
present invention.
[0021] Similar to the method of FIG. 1, at step 10, incoming coil
stock is first uncoiled and generally straightened. The coil stock
is a continuous sheet of metal that can be stamped, cut, or
otherwise machined to form a saw blade. As used herein, "coil
stock" refers to the material that is used to form the saw blade
before the saw blade is complete (e.g., before the blade is fully
formed with cutting teeth).
[0022] At step 14, the coil stock is blanked into a desired shape.
For example, the coil stock may be stamped or cut to form one or
more reciprocating saw blade blanks 30 (FIGS. 3, 5A, and 5B). A
"blank" refers to a piece of coil stock without cutting teeth. In
the illustrated embodiment, each blank has the general overall
shape of a finished blade, including a body 34, an attachment
portion 38, and a cutting tip 42, but does not include cutting
teeth. The illustrated attachment portion 38 includes a tang 46 and
an aperture 50 configured to engage a reciprocating saw or other
power tool. In other embodiments, the coil stock may be blanked
into a jigsaw blade blank or hole saw blank without cutting
teeth.
[0023] The saw blade blank 30 is also set at step 14. During
setting, portions of the saw blade blank 30 are set (e.g., bent)
out of alignment with the remainder of the blank 30. As shown in
FIG. 5A, portions along an edge 54 of the body 34 (which later
defines a cutting edge of the saw blade) are set in opposing
directions relative to the body 34 such that the edge 54 is
generally wave-shaped. For example, a first portion 58 may be set
in a first direction relative to the body 34, while a second
portion 62 may be set in a second direction relative to the body
34. Regions 64 between the first and second portions 58, 62 are
contoured or radiused to provide relatively smooth transitions. In
other embodiments, as shown in FIG. 5B, a blank 30' includes a body
34' having an edge 54' with more abrupt transition regions 64'
between first and second portions 58', 62'. Such embodiments
provide a shear profile along the edge 54'. In either of the
illustrated embodiments, the set magnitudes in the first and second
directions are generally the same. In other embodiments, the set
magnitude in the first direction may be larger or smaller than the
set magnitude in the second direction.
[0024] In some embodiments, the order of the blanking and setting
operations may be reversed. For example, in alternative
embodiments, portions of the coil stock may be set before the coil
stock is machined into individual saw blade blanks.
[0025] FIGS. 3 and 4 illustrate a machine 66 for setting the saw
blade blanks 30 of the coil stock. The machine 66 includes a press
70 to form a set pattern into each blank 30 before cutting teeth
are formed in the blanks 30. The illustrated press 70 includes an
upper die set 74 and a lower die set 78. Each die set 74, 78
includes a series of individual inserts 82A-C. During operation, a
saw blade blank 30 is positioned between the upper and lower die
sets 74, 78, and the die sets 74, 78 are pressed together such that
the inserts 82A-C contact and bend the edge 54 of the blank 30 in a
desired set pattern. In some embodiments, the blank 30 is
positioned within the press 70 so that any stress risers created
during setting are located in areas of the blank 30 that are later
removed to form gullets between cutting teeth. In the illustrated
embodiment, portions of the edge 54 of the blank 30 are set in
opposing direction simultaneously. In other embodiments, some
portions of the edge 54 may be set in a first direction, and then
other portions of the edge may be set in a second direction.
[0026] In the illustrated embodiment, each die set 74, 78 includes
three different groups of inserts 82A-C. The first group of inserts
82A is configured to set portions of the blank 30 in the first
direction. The second set of inserts 82B is configured to set
portions of the blank 30 in the second direction. The third set of
inserts 82C is configured to maintain portions of the blank 30 as
unset. In the illustrated embodiment, the inserts 82A-C are
arranged to create a repeating set pattern of second direction,
first direction, second direction, first direction, unset. In other
embodiments, the inserts 82A-C may be rearranged to create other
desired set patterns on the saw blade blank 30.
[0027] Referring back to FIG. 2, at step 18, cutting teeth 86
(FIGS. 6-8) are formed on the edge 54 of the saw blade blank 30.
The cutting teeth 86 may be formed by grinding, laser cutting, or
otherwise machining the teeth 86 into the edge 54. In the
illustrated method, two grinders (or other suitable machines) are
positioned downstream of the press 70 to form the cutting teeth 86
on two blanks 30 simultaneously. As shown in FIG. 7, each cutting
tooth 86 includes a tip 90, a rake face 94 extending from the tip
90, and a relief face 98 extending from the tip 90 opposite the
rake face 94. The grinders also form gullets 102 between each pair
of adjacent cutting teeth 86. Once formed, the cutting teeth 86 and
the gullets 102 define a cutting edge 106 of a saw blade 110.
[0028] Referring back to FIG. 2, at step 22, the saw blade 110
(FIGS. 6-8) is placed in a washer for cleaning. The washer removes
grinding debris, coolant residue, and other excess materials from
the blade 110.
[0029] After washing, a pick and place unit loads the saw blade 110
into a heat treat tray at step 26. The saw blade 110 is then heat
treated, tempered, or otherwise hardened, as desired for a
particular application. In some embodiments, the saw blade 110 may
also be coated and/or painted before or after heat treating.
[0030] FIGS. 6-8 illustrate the saw blade 110 manufactured by the
process of FIG. 2 compared to a saw blade 114 manufactured by the
process of FIG. 1. As shown in FIG. 6, tips 118 of cutting teeth
122 of the saw blade 114 manufactured by the process of FIG. 1 may
be excessively bent and damaged during setting. Such damage occurs
because the cutting teeth 122 are contacted and set after the tips
118 are formed. In contrast, the tips 90 of the cutting teeth 86 of
the saw blade 110 manufactured by the process of FIG. 2 are
undamaged because the tips 90 are not contacted by additional
machines after the tooth forming step.
[0031] In addition, as shown in FIG. 7, the shape and size of the
cutting teeth 122 of the saw blade 114 manufactured by the process
of FIG. 1 generally vary along the length of the saw blade 114. In
particular, some of the cutting teeth 122 are generally wider and
shorter than other cutting teeth 122. Such variations occur because
the setting machine contacts and presses against the cutting teeth
122, which may unintentionally deform those teeth 122 relative to
the other teeth 122. In contrast, all of the cutting teeth 86 of
the saw blade 110 manufactured by the process of FIG. 2 are
generally the same shape and size (within approved manufacturing
tolerances) because the teeth 86 are not contacted by additional
machines after they are formed.
[0032] Furthermore, as shown in FIG. 8, the tip 90, 118 of each
cutting tooth 86, 122 defines a plane 126A-C, 130A-C that extends
along a thickness of the corresponding saw blade 110, 114. The
planes 130A-C defined by the tips 118 of the saw blade 114
manufactured by the process of FIG. 1 are skewed relative to each
other. That is, the plane 130A defined by the cutting tooth 122 set
in the first direction is different than the plane 130B defined by
the cutting tooth 122 set in the second direction, and both planes
130A-B are different than the plane 130C defined by the unset
cutting tooth 122. In contrast, the planes 126A-C defined by the
cutting teeth 86 of the saw blade 110 manufactured by the process
of FIG. 2 are all generally parallel to each other, regardless of
the set orientation of a particular cutting tooth 86. In the
illustrated embodiment, each of the planes 126A-C extends generally
parallel to the thickness of the saw blade body 34. In other
embodiments, the tips 90 of the cutting teeth 86 may be
purposefully tilted relative to the body 34 such that the planes
126A-C likewise extend at an angle relative to the body 34. Since
all of the illustrated cutting teeth 86 are generally the same
height (within acceptable manufacturing tolerances), the
illustrated planes 126A-C are also generally coplanar. In other
embodiments, the cutting teeth 86 may be formed at different
heights, yet the planes 126A-C defined by the tips 90 are still
parallel.
[0033] Forming the cutting teeth 86 with parallel tips 90 helps
evenly distribute a cutting load over the cutting teeth 86, thereby
producing a smoother cut surface in a work piece. The configuration
may also improve cutting speed of the saw blade 110, material
removal from the work piece being cut, and/or cutting tooth
durability (e.g., resistance to fracture, blade life, etc.).
[0034] The manufacturing process depicted in FIG. 2 reduces capital
expenditures by not requiring multiple setting machines. Instead, a
less expensive press 70 (FIG. 3) is used to set the saw blade
blanks 30. In addition, the saw blades 110 produced by the method
of FIG. 2 have more consistent tooth sets than saw blades produced
by traditional setting processes (e.g., using the method of FIG.
1). For example, traditional saw blades may have a set variance or
tolerance of +/-0.003 inches, while saw blades manufactured by the
process of FIG. 2 have a set variance or tolerance of +/-0.0015
inches. Obtaining consistent product results (e.g., cutting tooth
shape, size, and set magnitude) is highly desirable in
manufacturing and for performance testing.
[0035] Although the invention has been described with reference to
certain preferred embodiments, variations and modifications exist
within the scope and spirit of one or more independent aspects of
the invention.
[0036] Various features and advantages of the invention are set
forth in the following claims.
* * * * *