Note: Descriptions are shown in the official language in which they were submitted.
AXIAL PLIERS
Technical Field of the Invention
The present invention relates generally to tools, such as pliers. More
particularly,
the present invention relates to a tool with jaw teeth geometry adapted to
grip a work
piece, such as a fastener head.
Background of the Invention
A typical problem encountered in the auto repair or carpentry trades is
fasteners,
such as, for example, pan head screws, socket head cap screws, and hex head
bolts and
nuts, that have been stripped out or rounded off, which thus make application
of torque
to such fasteners difficult. In such a case, pliers can be used to remove the
stripped
fastener by apply a large amount of clamping force, wherein the jaw teeth dig
into the
fastener. However, this typically causes additional stripping of the fastener,
or if the
fastener is too stripped or rounder, this does not work. Another option is to
use a bolt
extractor tool, if available and present. However, bolt extractor tools are
typically size
dependent, and thus require a plurality of different sizes. Also, use of bolt
extractor tools
are limited to specific types of fasteners as well.
For fasteners that are offset from the surface, such as hex head bolts or
socket
head cap screws, a socket-type tool with an interior diameter of spiraled
teeth has been
used. However, the effectiveness of this tool is determined by the available
engagement
area on the fastener. Likewise, these tools are fastener size dependent as
well, thus a
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Date Recue/Date Received 2021-05-31
plurality of differently sized removal tools are required. For other types of
low-profile
fasteners, such as pan head screws, a bolt extractor with spiraled teeth on
the outside of
the diameter has been used. However, this tool requires that a hole is drilled
into the
fastener and many sizes of extractors must be kept on hand for various sized
fasteners.
Another example of a tool used to remove stripped screws and bolts is locking
pliers with a four-bar linkage is able to generate a large amount of clamping
force on the
fastener head. Locking pliers are best engaged to the fastener by being
aligned
orthogonal to the fastener axis but may be also used by engaging the tool
axially with the
fastener. However, locking pliers are best suited for larger diameter screws
and bolts and
may not work for pan head screws or fasteners with a sloped head.
Another example of pliers adapted to remove stripped screws and bolts is
embodied in the 612AEP pliers, manufactured by Snap-on Incorporated of
Kenosha,
Wisconsin, where a set of teeth are oriented along the pliers axis and which
start at the
front face. These teeth are set on an arc such that when the pliers' jaws are
closed, the
teeth form a round hole, as shown.
Another example of pliers adapted to remove stripped-out screws and bolts is
disclosed in U.S. Patent Nos. 6,923,097 and 8,656,812. These patents disclose
pliers
having a "vamplier" design that includes a set of teeth oriented along the
pliers' axis, in a
manner similar to the 612AEP design, and are formed at an angle away from the
neutral
plane of the closed jaws. Accordingly, a sloped tunnel is formed or the teeth
lie on a
radius such that a concave shape is formed in the jaw surface.
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Summary of the Invention
The present invention broadly comprises a tool, such as pliers, having a jaw
tooth
geometry adapted to enhance gripping of fasteners, such as screws, pins,
bolts, and nuts,
when the axis of rotation of the fastener is substantially parallel with a
major axis of the
tool. In other words, the tooth geometry improves the grip on a fastener when
the
engagement is such that the axis of rotation of the fastener is orthogonal to
the plane that
defines the front of the jaws of the pliers. The tooth geometry can include a
gripping
pattern that enhances gripping with a fastener, where the normal force is
oriented close
to, or past orthogonal to, the axis of rotation of the fastener, so that the
fastener can be
engaged with the tool end-on and turned and/or pulled by the tool.
In an embodiment, the gripping pattern can be cut on a radius into a front of
the
jaws of the pliers. From the front, the gripping pattern may extend towards a
back of the
gripping area and veer off an axis at an angle. In an embodiment, the gripping
pattern can
follow a curve from the front of the jaws to the back of the gripping pattern,
such that the
teeth are on a radius where the center of the radius is set a distance from
the front of the
jaws. The teeth may be disposed on a depression, which is dished in two
orthogonal
directions where neither axis aligns with any major feature of the pliers,
that starts at the
front face of the jaw and terminates at a distance defined by a front to back
dish radius
starting point. Where the dished area meets the front edge/plane of the jaws,
the center
point of the depression may be equidistant from both sides of the jaws.
For example, the present invention broadly includes a tool. The tool includes
first
and second halves pivotally coupled together and a grip portion including a
surface with
a depression. The surface has a first set of teeth disposed on the depression.
The first set
of teeth abut a front face of the grip portion and extend away from the front
face at an
angle that is offset from a major axis of the tool.
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The present invention can further broadly comprise a tool that includes a
handle
portion having a first axis that is substantially perpendicular to a front
face of the tool,
and a grip portion adapted to engage a fastener and having a first set of
teeth disposed on
a surface with a depression that follows a first curve that is in a first
plane and a second
curve that is in a second plane. The first set of teeth abut the front face
and extend away
from the front face at an angle that is offset from the first axis.
The present invention can further broadly comprise a pliers-type tool. The
pliers-
type tool including a first half that includes a first handle portion, a first
joint portion
having an aperture adapted to receive a fastener, and a first grip portion
including a first
surface with a first depression, the first surface having a first set of teeth
disposed on the
first depression, wherein the first set of teeth abut a front face of the
pliers-type tool and
extend away from the front face at a first angle that is offset from a major
axis of the
pliers-type tool. The pliers-type tool further including a second half that
includes a
second handle portion. a second joint portion having a slot adapted to receive
the fastener
to couple the first and second halves, and a second grip portion including a
second
surface with a second depression, the second surface having a second set of
teeth
disposed on the second depression, wherein the second set of teeth abut the
front face
and extend away from the front face at a second angle that is offset from the
major axis.
Brief Description of the Drawings
For the purpose of facilitating an understanding of the subject matter sought
to be
protected, there are illustrated in the accompanying drawings embodiments
thereof, from
an inspection of which, when considered in connection with the following
description,
the subject matter sought to be protected, its construction and operation, and
many of its
advantages should be readily understood and appreciated.
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Fig. I is a side, perspective view of a tool according to an embodiment of the
present invention.
Fig. 2 is a side plan view of the tool of Fig. 1.
Fig. 3 is a side, perspective view of one half of the tool of Fig. 1 in a
.. disassembled condition.
Fig. 4 is an enlarged, partial view of a tool jaw of the tool of Fig. 1.
Fig. 5 is a section view of a tool jaw of the tool of Fig. 1 taken along line
5-5 of
Fig. 3.
Fig. 6 is an enlarged, perspective view of a tool jaw of the tool of Fig. 1.
Fig. 7 is a plan view of the front of a tool, according to an embodiment of
the
present invention.
Fig. 8 is a plan view of the front of a tool, according to an embodiment of
the
present invention.
Detailed Description of the Invention
While the present invention is susceptible of embodiments in many different
forms, there is shown in the drawings, and will herein be described in detail,
embodiments of the invention, including a preferred embodiment, with the
understanding
that the present disclosure is to be considered as an exemplification of the
principles of
the present invention and is not intended to limit the broad aspect of the
invention to any
.. one or more embodiments illustrated herein. As used herein, the term
"present invention"
is not intended to limit the scope of the claimed invention, but is instead
used to discuss
exemplary embodiments of the invention for explanatory purposes only.
The present invention broadly comprises a tool, such as pliers, having
gripping
jaw teeth that provide an enhanced contact pattern over the prior art for
engaging
fasteners, such as screws, pins, bolts, stripped fasteners, and other round or
near round
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fasteners when engaging the fastener on-axis. The gripping teeth may be formed
in a
dished area disposed at a distal end of a jaw of the pliers and are oriented
at an angle that
turns away from a major axis of the pliers and/or an axis that is orthogonal
to a plane
formed by a front face of the jaws. The angle and greater contact area
enhances the
amount of torque that can be applied to the fastener before the tool
disengages or "slips
against" the fastener, compared to the prior art tools.
Referring to FIGs. 1-8, a tool 100, such as pliers, includes a first potion
102. The
first 102 portion includes a handle portion 104, a joint portion 106, and a
grip portion
108 (also referred to as a jaw). The first portion can include an aperture
110. The
aperture 110 may be disposed in the joint potion 106. The pliers also include
a second
portion 112 that may include a handle portion 114, a joint portion 116, and a
grip portion
118. In an embodiment, the second portion 112 may include a slot 120 adapted
to
pivotally couple with the aperture 110 in the first portion 102 via a
fastener, such as a
screw, pin, or rivet, thus allowing the first and second portions to be
pivotal relative to
each other. The slot 120 can further allow the opening between the first and
second
gripping portions 108 to change, by moving or sliding the first portion 102
relative to the
second portion 112 along the slot 120. The tool 100 may be any of the variety
of tools in
the family of pliers, such as locking pliers, water pump pliers, linesman
pliers, or the
like, in which a tool is composed of at least a gripping section, a pivot
point, and handles
and where force is amplified by the ratio of the length of the handles to the
length of the
jaws about the pivot point. Embodiments of the invention disclosed herein
embody the
fastener-gripping portion (i.e., jaws) of any such pliers.
The gripping portions 108, 118 may include respective first tooth regions 122,
124 and second tooth regions 126, 128, with differing tooth patterns. In an
embodiment,
an axis system [xl, yl, zl] can be aligned with the respective handle portions
104, 114.
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However, the axis system is not limited to being aligned with the handle
portions 104,
114 and can be aligned in any desired alignment relative to the handle
portions 104, 114.
Teeth in the second tooth regions 126, 128 can be cut along the major 'yl'
axis and
formed in the [xl yl] plane as a grid pattern. In another embodiment, the
teeth in the
second tooth regions 126, 128 may not be aligned with the axis system.
Referring to Fig. 5, another axis system [x2, y2, z2] can define the grip
portions
108, 118 where the plane [y2 z2] defines the front faces 134, 136 of the
respective grip
portions 108, 118 and where the x2 axis is orthogonal to this plane.
Alternately, the plane
[y2 z2] may not define the front faces 134, 136 such that the x2 axis is at an
angle
relative to the front faces 134, 136. The coordinate system defining the
respective grip
portions 108, 118 may or may not be aligned with the handle coordinate system
[xl, yl,
z1].
The surface of the second tooth regions 126, 128 can have respective
depressions
130, 132 (also referred to as a concave bowl). The teeth disposed on the
depressions 130,
132 can abut respective front faces 134, 136 of the grip portions 108, 118 and
extend
towards the joint portions 106, 116 at an angle offset from the major 'xl'
and/or 5c2'
axes of the pliers at an angle a. The teeth disposed on the depressions 130,
132 may be
cut in a continuous pattern, as illustrated, or cross-hatched such that an
array of teeth are
formed in a grid pattern.
In an embodiment, angle a may range from about 10 to about 15 off of the xl
and/or the x2 axes. For example, the angle a may range from about 10 to 100, 2
to 7 , 30
to 8 , etc. off of the xl and/or x2 axes. Preferably, angle a is 5 off of the
xl and/or the
x2 axes. Referring to Fig. 7, the teeth disposed in the respective depressions
130, 132 of
the respective first and second portions 102, 112 may have substantially same
angle a,
such that when the tool 100 is in a closed state, the teeth disposed in the
depressions 130,
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132 of the respective first and second portions 102, 112, form a substantial
spiral or
helical pattern. The spiral or helical pattern of the teeth has been found to
cause the tool
100 to be further pulled onto a fastener when the tool 100 is rotated about an
axis of
rotation of the fastener. In an embodiment, angle a may be positive or
negative,
depending on the direction of rotation (e.g., clockwise or counter-clockwise)
required to
rotate the tool 100 to engage the fastener. Alternately, as illustrated in
Fig. 8, the teeth
disposed in the respective depressions 130, 132 of the respective first and
second
portions 102, 112 may have opposing angles a, such that when the tool 100 is
in a
substantially closed condition, the teeth disposed in the respective
depressions 130, 132
of the respective first and second portions 102, 112, form a substantially
identical
pattern.
The inventors of the present invention conducted extensive testing of tools
according to embodiments of the present invention and compared it to results
of the same
testing conducted on a typical pliers tool having a "vamplier" design
(indicated as "prior
art.' in the tables below). A first tool according to an embodiment of the
present
invention had an angle a of 0 was tested ("Tool 1, a=0 "), a second tool
according to an
embodiment of the present invention had an angle a of 2 ("Tool 2, a=2 "), and
a third
tool according to an embodiment of the present invention had an angle a of 5
("Tool 3,
a=5 "). As shown by the following testing, the embodiments of the present
invention are
able to apply more rotational force (torque) to an indicated fastener before
slipping off,
compared to typical pliers having a "vamplier" design.
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Fastener: 3/16 socket head capscrew
(0.37" outside diameter)
Normalized Average of
Tested Tool Max Torque to Slip
(%)
Prior Art 100.0
Tool 1 a =00 107.3
Tool 2 a =2 120.1
Tool 3 a =5 121.1
Table 1
Fastener: 18-8 SS 5/8 panhead screw
(0.475" outside diameter)
Normalized Average of
Tested Tool Max Torque to Slip
(%)
Prior Art 100.0
Tool 1 a =0 114.6
Tool 2 a =20 109.5
Tool 3 a =5 117.4
Table 2
The above tables show the normalized average, represented as a percentage, of
the maximum amounts of torque applied to the indicated fasteners during
testing of the
tools according to embodiments of the present invention having various angles
a
compared to a typical pliers design. As compared to the typical pliers design,
the present
invention tool 100 can apply more rotational force before slipping off the
fastener,
thereby enhancing the ability to remove damaged fasteners, such as, for
example,
stripped out fasteners.
Referring to Fig. 5, the teeth disposed in the respective depressions 130, 132
may
be cut along a first curve 138 in a plane that defines the respective
depressions 130, 132,
thereby forming a substantially concave dish. The plane may be disposed at an
angle
such that it is not parallel to the xl and/or the x2 axes. Alternately, the
plane may be
parallel to the xl and/or the x2 axes. The first curve 138 may be defined by a
radius 140.
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The length of the depressions 130, 132 is defined by a distance 142 that a
center of origin
of the radius 140 is from the front faces 134, 136 of the respective grip
portions 108,
118, and by a distance 144 of the origin of the radius 140 above the grip
portions 108,
118. Alternately, the first curve 138 may follow a parabolic or spline path or
may follow
a straight-line path.
Referring to Fig. 6, a second curve 146 can further define the respective
depressions 130, 132 and is defined by a radius 148. The second curve 146 may
be
disposed at an angle such that the second curve 146 is on a plane that is not
orthogonal or
perpendicular to the xl and/or the x2 axes. Alternately, the second curve 146
may be on
a plane that is orthogonal or perpendicular to the xl and/or the x2 axes. The
origin of the
radius 148 may be set at a distance 150 above a surface of the grip portions
108, 118,
which is illustrated by line 152, and at a distance 154 from an edge of the
grip portions
108, 118, such that the teeth disposed in the respective depressions 130, 132
are
substantially symmetrically disposed in the front faces 134, 136 of the
respective grip
portions 108, 118, where the cut of the depressions 130, 132 intersects the
respective
front faces 134, 136 of the grip portions 108, 118 in the [y2 z21 plane. The
teeth in the
depressions 130, 132 can be formed with a tooth angle f3 and a tooth depth 156
to couple
with a broad range of fasteners with different diameters and cross-sectional
shapes.
In an embodiment, the tooth angle r3 and tooth depth 156 are dependent on the
radius 148 and the type and dimensions of fasteners to be coupled. Likewise,
the radius
140 and the origin location of the first curve 138, as defined by distances
142 and 144,
can be defined such that an optimal normal force is achieved for a range of
fastener types
and sizes. The tooth angle J3 may range from about 20 to about 120 and is
preferably
40 -70 . The teeth disposed in the depressions 130, 132 may be separated by a
radius
trench varying in radius from about 0.002 to about 0.01 inches, or a flat
trench varying in
CA 3059697 2019-10-23
length from about 0.002 to about 0.01 inches. The tooth depth 156 may range
from
about 0.005 inches to about 0.1 inches, preferably about 0.01 to about 0.07
inches. The
radius 148 may range from about 0.04 inches to about 2 inches. In addition,
the second
curve 146 may be a complex curve, such as a parabolic or a spline, and may
extend
across the entire front faces 134, 136 of the respective grip portions 108,
118. In an
embodiment, the second curve 146 may follow a straight line path. The distance
150
defining the depth of the cut for the second curve 146 may range from about
0.02 inches
to about 2.1 inches. The difference of the distance 150 subtracted from the
radius 148
can be between about 0.01 and about 0.2, but not so great that the thickness
of the grip
portions 108, 118 at its thinnest point is less than about 0.07 inches. The
distance 154
may be about half of the grip portions 108, 118 width plus or minus about 0.2
inches to
cause the depressions 130, 132 to be placed on or about the center of the grip
portions
108, 118.
The radius 140 defining the first curve 138 may range from about 0.04 inches
to
about 2 inches. And the distance 144 defining the depth of the cut along the
first curve
138 may range from about 0.02 inches to about 2.1 inches. The difference of
the distance
144 subtracted from the radius 140 may be between about 0.01 and about 0.2,
but not so
great that the thickness of the grip portions 108, 118 at its thinnest point
is less than
about 0.07 inches. The distance 144 may range between about 0.002 inches and
about
seven-eighths of the radius 140. In an embodiment where the first curve 138 is
a
hyperbola, the distance 144 may range from about 0.002 inches to about 0.5
inches.
While aspects of the disclosure describe a tool having a grip portion
delineated
into three teeth sections, other configurations are possible. For example, a
configuration
can include the first tooth regions 122, 124 as a cutting section, or can
exclude the first
tooth regions 122, 124 such that the second tooth sections 126, 128 extends
all the way
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the joint portions 106, 116. Further yet, the grip portions 108, 118 may be
formed
entirely of the depressions 130, 132, in other words a dish-shaped, single
section jaw.
The matter set forth in the foregoing description and accompanying drawings is
offered by way of illustration only and not as a limitation. While particular
embodiments
have been shown and described, it will be apparent to those skilled in the art
that changes
and modifications may be made without departing from the broader aspects of
the
inventors' contribution. The actual scope of the protection sought is intended
to be
defined in the following claims when viewed in their proper perspective based
on the
prior art.
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