Note: Descriptions are shown in the official language in which they were submitted.
CA 02299215 2000-02-16
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HAND TOOL HAVING PIVOTED HANDLES
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a pivoted handled tool for grasping, holding or
cutting
workpieces having various configurations.
2. Description of Background Information
It is known, for example in U.S. Patent No. 5,022,291 to McBain, to provide a
pivoted handle tool having at least one pivotable jaw for engagement with a
workpiece
having a range of different sizes, such as nuts or bolts. The pivotable jaws
have flat
planar surfaces opposing one another, and the handles include an adjustable
pivotable
connection to enable the hand tool to engage a plurality of different sized
fasteners.
However, the flat planar surfaces of the jaws do not permit sufficient
engagement with
the outer surfaces of the nut such that when a turning force is applied by the
hand tool of
McBain, the tool can readily slip off the fastener or cause the outer surfaces
to become
rounded thereby rendering removal or installation of the fastener to be
difficult if not
impossible.
Another conventional hand tool having pivoted handles and including a locking
feature is shown in U.S. Patent No. 4,601,221 to Kalkbrenner et al., which
discloses a
clamping device for rectangular configurations that includes two opposed jaws
each
having a pivotally mounted, right-angled jaw portion which form a self
adjusting
rectangular opening for engaging and holding a rectangular workpiece. The jaws
are
disclosed as engaging only square or rectangular workpieces and the jaws
encompass the
entire perimeter of those workpieces or the entire perimeter of an arrangement
of a
plurality of rectangular workpieces that are desired to be clamped together.
It is clear that
the self adjusting jaws disclosed in Kalkbrenner et al. are not intended to
engage the
heads of threaded fasteners for applying a rotational force or torque thereto.
Conventional locking pliers are disclosed in U.S. Patent No. 3,635,107 to
Schmidt.
The locking pliers disclosed herein include fixed planar jaw portions, with or
without
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toothed segments, fixed curved jaw portions including toothed segments and
combinations of fixed planar and toothed segments. However, there is no
disclosure of
a self adjusting pivoted jaw for engagement of a mufti-sided workpiece to
apply a
rotational force or torque thereto, nor is there disclosure of the pivoted
jaws being formed
with cutting segments, or of a locking pliers having two jaw members pivotally
attached
to one elongated member to provide a greater range of movement.
Additionally, U.S. Patent No. 2,464,145 to Mead and U.S. Patent No. 2,558,440
to Johnson both disclose hand tools having pivoted handles which include a
slot formed
in one of the handles at the pivotal connection to permit the hand tool to
accommodate
workpieces of various sizes. However, neither of these conventional pivoted
handle tools
provide an adjustment slot in both of the pivoted members to permit greater
adjustability
and accommodation of workpieces having larger sizes.
SUMMARY OF THE INVENTION
The present invention overcomes deficiencies in the prior art relative to the
ability
of the jaws of a hand tool having pivoted handles to maintain sufficient
contact with a
mufti-sided workpiece, such as a hexagonal fastener, for example a nut or
bolt, when a
rotational force or torque is applied. This results in an increased ability of
the pivoted
handle hand tool to apply a sufficient rotational force or torque to the
workpiece and to
provide proper engagement therewith to prevent rounding or other damage.
Furthermore, a hand tool embodying the pivoting self adjusting jaws of the
present
invention enjoys enhanced engagement of a mufti-sided workpiece, such as a
hexagonal
fastener, by providing engagement on four sides of the fastener with the jaw
surfaces.
Accordingly, the torquing capacity of the hand tool is increased, as is the
ability of the
tool to effectively engage and rotate a hexagonal fastener having worn or
rounded
surfaces as well as an undamaged hexagonal fastener.
Additionally, the present invention overcomes the deficiency in prior art
toggle-
link type hand tools by providing the pivotally interconnected jaws with
cutting surfaces
to facilitate gripping and cutting of work pieces thereby, and by providing a
pair of
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pivotally interconnected jaw members on elongated members for increased
efficiency in
the actuation thereof.
According to a first aspect of the present invention, the hand tool is
provided that
includes at least two elongated members pivotally interconnected by a pivot
joint to
provide a pair of handles and a pair of jaw carrying members. Each jaw
carrying member
includes a self adjusting jaw pivotally connected thereto, and each self
adjusting jaw is
configured to have an angle-shape whereby operation of the handle causes
engagement
of a multi-sided workpiece by the angle-shaped jaws to enable firm engagement
with a
workpiece and imparting of a rotational force or torque thereto. Each angle-
shaped jaw
may be configured to engage two sides of a hexagonal fastener, and the pivot
joint may
be configured as a slip joint.
According to a further aspect of the invention, the slip joint may include a
slot
formed in at least one of the elongated members, and the slot includes at
least two
adjusting notches therein. A pin for pivotally interconnecting the elongated
members is
mounted on the other of the elongated members, and is movable within the slot
from one
adjusting notch to the other, thereby permitting adjustment of jaw spacing to
accommodate different size fasteners. Additionally, the slot may be provided
with more
than two adjusting notches to permit greater adjustability of the hand tool.
According to another aspect of the invention, the hand tool is configured to
have
a?0 a second slot formed in the other of the elongated members, with the
second slot having
at least two adjusting notches therein. Furthermore, the pin for
interconnecting the
elongated members is rotatably mounted and is configured to have a D-shaped
cross-
section, whereby the pin is rotatable to align the flat side of the D-shape
with a
longitudinal dimension of each of the slots to permit sliding movement of both
elongate
5 members relative to one another to provide adjustment and to position the
curved side of
the pin within the respective notches to prevent relative pivoting of the
elongated handles
to allow operation of the hand tool.
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Additionally, one end of the rotatable pin may be provided with a head, and
the
other end of the rotatable pin may be provided with a knurled knob to
facilitate rotation
of the pin to a desired position. Furthermore, each of the slots may be
provided with more
than two adjusting notches to permit greater adjustability of the hand tool.
Moreover, the pivoted handle tool may further include an angle-shaped self
adjusting jaw pivotally mounted to each of the elongated members for
engagement with
a multi-sided workpiece, and in particular each angle-shaped self adjusting
jaw may be
configured to engage two adjacent sides of a hexagonal fastener.
According to another aspect of the invention, a toggle-link type hand tool is
provided that includes pivotally interconnected elements having workpiece
engaging
members and a pair of handles each operatively connected to a respective one
of the
pivotally interconnected elements, and a toggle-link operatively connected
between the
handles. Additionally, each of the workpiece engaging members includes a self
adjusting
jaw pivotally connected thereto and each jaw is configured to have an angle-
shape for
engagement with two adjacent sides of a hexagonal fastener. Additionally, the
pivotable
connection of at least one of the self adjusting jaws to a respective
workpiece engaging
member may be provided by a slot formed in one of the jaw and the member and a
pin
fixed to the other of the jaw and the member to provide greater adjustability
of the jaws.
According to a further aspect of the invention, a toggle-link type hand tool
is
provided that includes pivotally interconnected elements having workpiece
engaging
members, a pair of handles, with each of the handles operatively connected to
a respective
one of the elements, and a toggle-link operatively connected between the
handles.
Furthermore, each of the workpiece engaging members is configured to have a
cutting
surface, and the cutting surfaces may be configured as straight blades or the
cutting
2 5 surfaces may be configured as curved cutting surfaces to facilitate
cutting of circular
members.
In accordance with a further aspect of the invention, a toggle-link type hand
tool
includes first and second elongated elements, a pair of workpiece engaging
members
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pivotally connected to the first elongated member, and the second elongated
member
forms a handle pivotally connected to one of the workpiece engaging members.
Additionally, a first toggle-link is operatively interconnected between the
first and second
elongated elements and actuating mechanism for the other of the workpiece
engaging
member. Thus, manipulation of the handle and operation of the actuating
mechanism
causes the workpiece engaging members to move toward and away from one another
to
facilitate engagement with the workpiece. The actuating mechanism may include
an
operating mechanism operatively interconnecting the pair of workpiece engaging
members for conjoint movement. Furthermore, the operating mechanism may
include a
l0 gear segment formed on each of the workpiece engaging members, with the
gear
segments meshing together so that movement of the one workpiece engaging
member by
operation of the handle transmits movement to the other workpiece engaging
member for
actuation thereof. Each workpiece engaging member may include a self adjusting
jaw
pivotally connected thereto, and each of the jaws may be configured to have an
angle-
l, 5 shape for engagement with two adjacent sides of a hexagonal fastener.
Furthermore, the workpiece engaging members may be provided with toothed
segments to provide a firm grip on workpieces engaged thereby. Moreover, the
actuating
mechanism may include a third elongated element forming a second handle
pivotally
connected to the other of the workpiece engaging member, and a second toggle-
link may
2 0 be operatively connected between the first and third elongated elements.
Moreover, the
first and second toggle-links may be each pivotally connected at a first end
to the
respective second and third elongated elements and may be each connected at a
second
end to the first elongated member for pivotable and longitudinal movement
relative
thereto.
2.5 The first elongated element may be formed from a pair of spaced apart,
complementary curved plates forming an elongate passageway in which the second
ends
of the toggle-links are pivotally and longitudinally moveable. The second ends
of the
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toggle-links may each be provided with two semi-spherical members, on opposite
sides
thereof, for permitting the pivotable and longitudinal movement within the
passage.
According to another aspect of the invention, the toggle-link hand tool may
further
include an adjustment member on the first elongated element for engagement by
the
second ends of the toggle-links, thereby providing adjustability for the
workpiece
engaging members. Furthermore, the adjustment member may be formed as a screw-
threaded member threadedly engaged with an outer end of the first elongated
element, and
an end of the screw-threaded member may engage the second ends of the toggle-
links to
provide adjustability. Furthermore, the second ends of the toggle-links may be
pivotally
t 0 interconnected, and two semi-spherical members may be provided on opposite
sides of
the second ends of the toggle-links for permitting the pivotable and
longitudinal
movement within the passage. Furthermore, an adjustment member may be provided
on
the first element for engagement by the second ends of the toggle-links to
provide
adjustability for the workpiece engaging members, and the adjustment member
may be
:l5 formed as a screw-threaded member threadedly engaged with an outer end of
the first
element and an end of the screw-threaded member engages the second ends of the
toggle-
links.
According to a further aspect of the invention, the toggle-link type hand tool
may
be formed such that the second and the third elongated elements are longer
than, and
a!0 extend outwardly beyond, an outer end of the first elongated element to
increase the
leverage of the hand tool, to permit operation of the hand tool by two hands,
and to
eliminate the need for a release lever for the locking mechanism. Each
workpiece
engaging member may also include a self adjusting jaw pivotally connected
thereto, and
each jaw may be configured to have an angle-shape for engagement with two
sides of a
~;S hexagonal fastener. Alternatively, each of the workpiece engaging members
may be
configured to have a cutting surface, and the cutting surfaces may be
configured as
straight blades or as curved cutting surfaces.
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According to a further aspect of the invention, each of the workpiece engaging
members may have an arcuate configuration, and a plurality of teeth may be
provided on
facing inner arcuate surfaces of the workpiece engaging members to facilitate
gripping
of a workpiece having a generally circular outer surface.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other features and advantages of the present invention will be
made
apparent from the following description of the preferred embodiments, given as
non-
limiting examples, with reference to the accompanying drawings, in which:
Fig. 1 is a perspective view of a self adjusting jaw utilized in accordance
with the
present invention;
Fig. 2 is a side elevation view of a first embodiment of the hand tool
according to
the present invention having a slip joint;
Fig. 3 is a side elevation view of a second embodiment of the hand tool of the
present invention having a slip joint;
:l 5 Fig. 4 shows the hand tool of the embodiment of Fig. 3 with the handles
separated
for clarity;
Figs. 5 and 6 show a side elevation view, and a cross-sectional view,
respectively,
of the connecting pin utilized in the embodiment of Figs. 3 and 4;
Fig. 7 is a side elevation view of the embodiment of Fig. 4 showing one
adjusted
position of the pivoted handles;
Fig. 8 is a side elevation view of the embodiment of Fig. 3 showing a
different
adjusted arrangement of the pivoted handles;
Fig. 9 is a side elevation view of a toggle-link type hand tool in accordance
with
the present invention and including a pair of self adjusting jaw members.
2 5 Figs. 10 and 11 are side elevational views of elements of the connection
between
the self adjusting jaw member and the toggle-link type hand tool.
Figs. 12 and 13 depict toggle-link type hand tools of the present invention
having
curved and straight cutting jaw portions, respectively;
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Fig. 14 depicts another embodiment of the toggle-link type hand tool in
accordance
with the present invention having gear segments operatively for
interconnecting the j aw
members for conjoint movement;
Fig. 15 depicts another embodiment of the toggle-link type hand tool of the
present
invention similar to that of Fig. 14, and having toothed jaw segments;
Fig. 16 depicts a side elevation view of another embodiment of the toggle-link
type
hand tool according to the present invention utilizing a pair of handle
members;
Figs. 17-20 illustrate two variations of the interconnections of the toggle-
links of
the toggle-link hand tool according to the present invention;
Fig. 21 is a side elevation view of another toggle-link type hand tool
according to
the present invention having a pair of elongated handles; and
Fig. 22 and Fig. 23 illustrate further embodiments of the toggle-link type
hand tool
according to the present invention including jaws formed with cutting surfaces
and
arcuate grasping surfaces, respectively.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to Fig. 2, a first embodiment of the hand tool according to the
invention
is depicted as slip joint pliers 8. The pliers 8 are formed from a first
elongated member
including a right handle 9, a plate-like body 10 and a left jaw 12. A second
elongated
member includes a left handle 17, a plate-like body (not numbered), and a
right jaw 18.
The left and right jaws 12,18 are offset with respect to the plate-like bodies
to which they
are connected at portions 14,19, respectively, to permit the outer ends of the
jaws to
directly oppose one another. The plate-like body portions are pivotally
interconnected by
a slip joint provided by adjusting notches 11 formed in the plate-like body 10
and a pin
23 connected to the plate-like body of the other elongated member, and the pin
23 extends
through the adjusting notches 11 in a conventional manner to allow two-
position
adjustability of the slip joint pliers. As can be seen from Fig. 2, a left-
side self adjusting
jaw 16 is pivotally mounted by a hinge pin 15 to the outer end of left jaw 12,
and a right-
side self adjusting jaw 21 is pivotally mounted via hinge pin 22 to the right
jaw 18. The
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left jaw 12 is configured to provide a recess 13 to accommodate pivotal
movement of the
left-side adjusting jaw 16 and the right jaw 18 is configured to provide a
recess 20 to
accommodate the pivoting movement of the right-side self adjusting jaw 21.
A self adjusting jaw l, which is representative of the self adjusting jaws
utilized
throughout this disclosure, is depicted in Fig. 1. Each self adjusting jaw 1
includes two
diverging angular side portions 2,3 that extend at an angle of about
120° and intersect at
an apex 4. The angular relationship of the side portions 2,3 is configured
such that both
side portions 2,3 fully engage along two adjacent sides of a hexagonal bolt
head or nut
24 as seen in Fig. 2. Thus, the opposed left-side and right-side self
adjusting jaws 16,21
are substantially opposed to one another and they self adjust about the
respective pivot
pins 15,22 to closely engage opposite sides of the bolt head or nut 24 as
shown in Fig. 2
to permit a strong gripping force to be applied to the fastener and to reduce
the likelihood
that the corners of the fastener may be rounded off. Furthermore, if the
corners of the
fastener have been rounded or damaged previously, the positive engagement of
the self
adjusting jaws along opposed sides of the fastener will enable sufficient
torque to be
applied thereto to effect rotation of the fastener. Additionally, the self
adjusting jaw 1 as
depicted in Fig. 1 includes outwardly extending hinge portions 5,6 each having
an
aperture 7 for receipt of a respective hinge pin 15,22 for pivotally mounting
the self
adjusting jaw on the associated jaw member. The self adjusting jaws and the
hinge pins
may be formed of any suitable material including metal, such as steel, and
preferably may
be formed of a spring steel alloy having a hardness range of about 59 to 61
Rockwell C.
Fig. 3 of the drawings illustrates another embodiment of the hand tool
according
to the invention which is formed as a pair of slip joint pliers 25. In this
figure like parts
are designated with the same reference numerals as those utilized in the
embodiment
depicted in Fig. 2, and the essential difference is that the plate-like body
26 is formed to
have a greater lateral expanse than that of the hand tool depicted in Fig. 2
to
accommodate an extended series of adjacent notches 27. Thus, the pin 23 can be
positioned in a desired notch to allow the self adjusting jaws 16,21 to
accommodate
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fasteners having a variety of sizes while maintaining the distance (D) between
the handles
17,9 (as shown in Fig. 3) to be at a minimum. With this arrangement, the
series of
notches 27 permits the slip joint tool 25 to accommodate larger work pieces
such as the
bolt 28 depicted in Fig. 3.
Another embodiment of the hand tool according to the invention will now be
described with reference to Figs. 4-7 which illustrate slip joint pliers 29.
This
embodiment includes larger plate-like bodies 26,33 respectively on the right
and left side
of the elongate members, and each plate-like body has an elongate series of
adjacent
notches 35,36 which, in the assembled and operative position, are superposed
and
interconnected by a loose pin 37. The outer ends of the elongated members
forming the
split joint pliers 29 are provided with conventional jaw members 32,34.
The loose pin 37 is illustrated in Figs. 5 and 6 and is configured as a rod
member
40 having a D-shape cross-section (Fig. 6) and includes a stopper end 41 at
one end of the
rod and a knurled knob 39 at the other end of the rod. Alternatively, the pin
37 may be
provided with a pair of knurled knobs, one positioned at each end of the rod
40 (not
shown).
The circle 38 shown in Fig. 4 depicts one position of the rod 40 in the series
of
notches in order to provide a pivotal connection between the respective
elongate members
forming the tool 29. In order to adjust the position of the handle 17,9 and
the respective
jaws 32,34, the loose pin 37 is moved to the appropriate one of the series of
notches. This
is accomplished by manually grasping the knurled knob 39 and rotating the pin
40 such
that the flat side of the D-shaped rod is aligned with the longitudinal
extension of the
series of notches 36 to allow the movement of the rod 40 from one notch to
another in the
series of notches 35 or the series of notches 36 or in both series of notches
35 and 36
either alternatively or simultaneously. Once the rod 40 is positioned in the
appropriate
notch or notches, the knurled knob 39 is rotated to a position prohibiting
movement of the
pin from the selected notches while permitting pivotal movement between the
elongated
members. It is apparent that the elongated series of notches 35,36 and the
cooperating
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loose adjusting pin 37 provide an even greater adjustability to the jaw
openings and
allows the handles 9,17 to maintain a minimum distance of separation
therebetween while
accommodating the various sized fasteners or workpieces between the jaws
32,34. This
permits the user to easily hold and squeeze the handles to apply a maximum
gripping
force to the fastener or workpiece. Fig. 7 is a side elevational view of the
hand tool of
this embodiment wherein the overlapping elongated series of notches 35,36 are
shown
engaged by the loose adjustment pin 37 at the ends thereof, which provides the
greatest
jaw opening distance.
Fig. 8 illustrates an alternative embodiment of split joint pliers 42 similar
to that
shown in Figs. 4-7. However, this embodiment includes larger plate-like bodies
45,46
and more robust left and right jaws 47,48 which are offset at 53,54,
respectively such that
the jaws 47,48 substantially oppose one another. Self adjusting jaws 32,34 are
pivotally
connected to the respective jaw members 47,48 by pins 55,56. The self
adjusting jaws
and the hinge pins may be formed of any suitable material including metal,
such as steel,
and preferably may be formed of a spring steel alloy having a hardness range
of about 59
to 61 Rockwell C. Again, the plate-like body 45 is provided with an elongate
series of
notches 51 and the plate-like body 46 is provided with an elongate series of
notches 52
which overlap with one another in the operative position, and the elongate
members are
pivotally interconnected by a loose pin 37 in the same manner as described
with respect
to Figs. 4-7. Thus, the hand tool according to this embodiment can accommodate
a large
size fastener head 57 in a self adjusting manner, and due to the adjustability
provided by
the loose pin 37 and the overlapping elongate series of notches, the spacing
d2 between
the handles 17,9 can be maintained at a minimum to provide the greatest
leverage possible
as well as to secure engagement of the fastener 57 by the self adjusting jaws.
Fig. 9 depicts a hand tool according to the present invention which is
configured
as a toggle-link type hand tool of the type generally called locking pliers
which are well
known in the art. Thus, it is not deemed necessary to explain in detail the
functioning of
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the known toggle-link arrangements and reference is made only to the relevant
parts
incorporating the novel features in accordance with the present invention.
Accordingly, locking pliers 60 include a first handle 66 having a fixed jaw 61
rigidly connected thereto and a movable jaw 62 pivotally connected to the
handle 66 by
pivot pin 63. Fixed jaw 61 and movable jaw 62 each have self adjusting jaws
43,44
respectively pivotally connected thereto via hinge pins 64,65. The self
adjusting jaws and
the hinge pins may be formed of any suitable material including metal, such as
steel, and
preferably may be formed of a spring steel alloy having a hardness range of
about 59 to
61 Rockwell C. A movable handle 69 is pivotally connected at one end to the
movable
jaw 62 by a pivot pin 71, and a toggle-link 68 is pivotally connected at one
end by the
hinge pin 70 intermediate the ends of the movable handle 69 and is operatively
connected
to the handle 66 at its other end in a conventional manner.
The outer end of handle 66 is provided with an adjusting screw 67 for
engagement
with the toggle-link 68 to provide the adjustable positioning of the fixed jaw
and movable
jaw relative to one another, and the movable handle 69 includes a release
lever 72
pivotally connected thereto by a pivot pin 73 for operation in a conventional
manner.
Accordingly, the self adjusting jaws 43,44 are configured to automatically
align with
opposed pairs of sides of a hexagonal workpiece, such as the fastener 74
depicted in Fig.
9. This arrangement provides more secure engagement by the jaws of the locking
pliers
~:0 to permit a strong gripping force to be applied to the fastener and to
allow a more
effective application of force or torque to a fastener or a workpiece which
reduces the
likelihood that the corners of the fastener will be rounded off during
application of the
torque. Furthermore, by use of the adjusting screw feature of the locking
pliers 60, the
self adjusting jaws can be properly positioned to provide the proper distance
between the
2.5 jaws 61,62 in order to apply a more effective gripping force and torquing
force.
Additionally, as can be seen from Fig. 10, the fixed jaw member 61 of the
locking
pliers 60 may be provided with a longitudinally extending slot 75 which
receives the
hinge pin 64 of the self adjusting jaw 43. Thus, during operation of the
locking plier 60,
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the hinge pin 64 can move lineally within the longitudinal slot 75 to provide
better
alignment of the self adjusting jaw members 43,44 to more accurately and
completely
engage the opposed pairs of sides of the hexagonal fastener to be gripped
therebetween.
Fig. 11 is a depiction of the self adjusting jaw 43 removed from its
application to the
fixed j aw 61.
Fig. 12 illustrates another embodiment of locking pliers 75, in which like
elements
in Fig. 12 are represented by the corresponding reference numerals previously
indicated
with respect to Fig. 9. In this embodiment, the fixed jaw 61 and the movable
jaw 62 are
each provided with respective cutting edges 76,77 for cutting a workpiece such
as a cable
78. The plane of pivoting of the movable jaw 62 is slightly offset from the
plane of the
fixed jaw 61. During the operation of the locking-pliers 75, in order to cut a
workpiece,
such as a cable 78, the cutting operation is performed in successive stages
during which
the movable jaw is closed to engage and cut a portion of the cable 78 by
operation of the
handle 69, after which the movable jaw is released and the adjustable screw 67
is
progressively tightened after each cutting stroke so that the jaws 61 and 62
move
progressively closer to one another until the workpiece is completely cut.
Furthermore,
the locking pliers 75 can be utilized to cut through the insulation coating on
the various
types of electrical wires and cables, or the like, in order to strip or peel
off the insulating
coating.
Another embodiment of locking pliers is illustrated in Fig. 13 wherein a pair
of
locking pliers 78 configured to be operated with both hands is depicted. The
locking
pliers 78 includes a fixed handle 82 having a fixed jaw 79 connected thereto.
A lower
fixed handle portion 88 receives an adjustment screw 89. The adjustment screw
89 has
an extended length, and includes a threaded portion 90 and an unthreaded
portion 91. A
movable jaw 80 is pivotally connected to the fixed handle 82 by a hinge pin
83, and a
movable handle 84 is pivotally connected to both the movable jaw 80 and a
toggle-link
in a conventional manner. The movable handle 84 is offset at 85 to provide an
upper
movable handle portion 86 and a lower movable handle portion 87 extending at
an angle
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thereto. During operation of the locking pliers 78, the lower fixed handle
portion 88 is
grasped by one hand of an operator and the lower movable handle portion 87 is
grasped
by the other hand for movement toward and away from one another which results
in the
movable jaw 80 moving toward and away from the fixed jaw 79. The fixed and
movable
S jaw 79 and 80 are each provided with straight, scissors-like blades, only
one of which is
shown for movable jaw 80 at 81. Due to the extended length of the fixed handle
82 and
the movable handle 84, and the two hand operation thereof, no release lever is
provided
since none is necessary. Locking pliers 78 are particularly useful for cutting
thick and
relatively hard material, such as sheet metal and the like. The cutting
operation for such
material may be performed by successive cutting strokes, with or without
changing the
position of the adjustment screw 89.
A further embodiment of locking pliers is illustrated in Fig. 14 incorporating
additional features of the present invention. In this embodiment, a pair of
movable jaws
93,94 are pivotally connected to a fixed handle 66 via respective hinge pins
101,103.
Movable jaw 93 includes a gear segment 102 which meshes with a gear segment
104
provided on movable jaw 94. A movable handle 69 is pivotally connected to the
movable
jaw 94 and also to a toggle-link 68 which is pivotally connected to the
movable handle
69 at one end and operatively connected to the fixed handle 66 at the other
end such that
movement of the movable handle 69 causes movement of the movable jaw 94 and,
the
meshing of the gear segments 102,104 results in conjoint movement of the
movable jaw
93. Thus, it can be seen that operation of the movable handle 69 toward and
away from
the fixed handle 66 results in movement of both jaws 93,94 toward and away
from one
another.
The movable jaws 93,94 are provided with offset portions 95,96 respectively,
and
the outer ends of the movable jaws are each provided with a respective self
adjusting jaw
16,21. The offsets 95,96 permit pivotal movement of the self adjusting jaws
without
engagement of the external bottom edges 97,98 of the self adjusting jaws with
the
inwardly directed edges 99,100 of the movable jaws. The locking pliers of this
14
CA 02299215 2000-02-16
P 19024. SO 1
embodiment, due to the conjoint movement of movable jaws 93 and 94 and the
pivoting
movement of the self adjusting jaws 16,21, permit precise adjustment of the
locking tool
and complete engagement of the self adjusting jaws with a hexagonal workpiece
such as
a fastener 105 to permit efficient application of a gripping force and a
rotational force or
S torque thereto. This construction results in efficient application of a
gripping force and
a torque to the fastener without rounding the edges thereof, and also permits
application
of a torque to a fastener having previously rounded corners due to the
engagement of the
pair of flat jaw surfaces with opposite adjacent sides of the fastener.
Fig. 15 illustrates a modification of the locking pliers depicted in Fig. 14
wherein
corresponding elements have been labeled with corresponding reference
numerals. In this
embodiment, movable jaws 106,107 are pivotally connected to a fixed handle
member for
conjoint movement in the same manner as disclosed in the embodiment of Fig.
14. The
movable jaws include offset portions 108,109, respectively, and generally
straight upper
portions 110,111. Movable jaw 106 is provided with a toothed portion 112 and
movable
jaw 107 is provided with a toothed portion 113. The toothed portions may be
provided
to have a reverse involute shape, or any other conventional tooth shape. The
locking
pliers of this embodiment having the toothed jaw portions can be
advantageously utilized
for gripping small objects therebetween.
Fig. 16 depicts a further embodiment of the hand tool according to the
invention
and in particular a locking pliers 114 provided with left and right
symmetrical jaws
115,116 which are pivotally connected to a central handle 119 by a pivot pin
127. Left
handle 117 is pivotally connected to left jaw 115 and a toggle-link 120 is
pivotally
connected at one end to the left handle 117 and operatively connected at the
other end to
the central handle 119. A right handle 118 is pivotally connected to the right
jaw 116, and
a toggle-link 121 is pivotally connected at one end to the right handle 118
and operatively
connected at the other end to the central handle 119. Lateral springs 124,125
are
respectively connected at first ends to a respective left and right jaw
115,116 and at their
opposite ends to a pin 126. The left and right jaws 115,116 are each provided
with offset
CA 02299215 2000-02-16
P 19024. SO 1
portions 128,129, respectively, such that the outer ends of the respective
jaws are
diametrically opposed. The left jaw 115 is provided at the upper end thereof
with a self
adjusting jaw 16 which is pivotally connected thereto by a pivot pin 15, and
the upper end
of the right jaw 116 has a self adjusting jaw 21 pivotally connected thereto
by a pin 22.
The offset portions 128 and 129 permit the self adjusting jaws 16,21 to move
in
substantially the same plane of motion. An adjustment screw 49 is provided at
the outer
end of the central handle 119 for adjustment of the toggle-links in the usual
manner, and
the outer ends of the handles 117,118 are respectively provided with release
levers
122,123 which operate in a conventional manner. This configuration of locking
pliers
l 0 provides uniform and conj oint movement of the j aws 15,16 upon operation
of the handles
117,118, and the self adjusting jaws 16,21 are symmetrically positioned about
the
workpiece or hexagonal fastener 17 to enable a gripping force and a rotational
force or
torque to be applied efficiently thereto.
Details of the connection of the toggle-links 120,121 with the central handle
119
~l5 are shown in Figs. 17 and 18. Referring to Fig. 17, which depicts a
horizontal cross-
section of the central handle 119, it can be seen that the central handle 119
is formed from
a pair of spaced plates 119a, 119b that are curved outwardly and oppositely in
the central
region thereof to provide a longitudinal guide for the ends of the toggle-
links 120,121.
Toggle-link 120 is provided at one end with a pair of semi-spherical pieces
130 positioned
?0 on opposite sides, and toggle-link 121 is provided at one end with a pair
of semi-spherical
pieces 131 also positioned on opposite sides thereof, as can be seen in Fig.
17. It can also
be seen from Fig. 17 that the pair of curved plates 119a; 119b forming the
central handle
119 provides a pair of open sides 132,133 through which the toggle-links
120,121 extend,
and the semi-spherical pieces 130,131 constrain the toggle-links for sliding
longitudinally
a! 5 within the central handle and pivoting with respect thereto, but prevent
the ends of the
toggle-links from moving laterally through the open sides 132,133 of the
central handle.
Turning to Fig. 18, it can be seen that the lowermost end of the central
handle 119
is formed with a female threaded portion which receives adjustment screw 49.
The ends
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CA 02299215 2000-02-16
P19024.S01
of toggle-links 120,121 abut the flat top of the adjustment screw 49 and are
urged toward
this position by springs 124,125. It can be seen that adjustment of the
adjustment screw
49 allows the locking pliers to accommodate heads of fasteners having various
sizes in
a manner to effect the desired clamping force on the head of the fastener.
S Figs. 19 and 20 illustrate a modification of the connection of the toggle-
links
within the central handle 119. In this embodiment, the ends of the toggle-
links 120,121
are pivotally interconnected by a pivot pin 134 which is formed with semi-
spherical heads
135,136 on opposite ends thereof. In this manner, the semi-spherical heads
constrain the
toggle-link ends to longitudinal and pivotal movement relative to the central
handle 119
while preventing lateral movement of the toggle-link ends out of the open
sides. As can
be seen from Fig. 19, the pivotally interconnected ends of the toggle-links
120,121 abut
the flat top surface of the adjustment screw 49 and are biased into engagement
therewith
by the springs 124,125 (Fig. 16).
Fig. 21 depicts an alternative embodiment of the locking pliers shown in Fig.
16.
This pair of locking pliers 139 is similar to that depicted in Fig. 16 except
that the left and
right handles 140,141 are longer and extend outwardly beyond the outer end of
the central
handle 119. Furthermore, the lower ends of 142,143 of the respective left and
right
handles diverge outwardly at an obtuse angle with respect to the upper
portions 144,145.
The increased length of the handles 140,141 permits operation of the locking
pliers 139
2 0 with both hands by an operator and provides an increased mechanical
advantage. Thus,
the bottom gripping portion 142 can be grasped with one hand and the bottom
gripping
portion 143 can be grasped with the other hand to provide movement of the
handles in
opposite directions to operate the self adjusting jaws 16,21 for engagement
with a
workpiece, such as the head of the fastener 17. Thus, not only do the longer
handles
2:5 provide a significant increase in the mechanical advantage of the locking
pliers 139, but
they also eliminate the need for release levers. The locking pliers 139 also
include the
self adjusting jaws 16,21 as described with reference to Fig. 16.
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CA 02299215 2000-02-16
P 19024. SO 1
Fig. 22 shows a further alternative arrangement of the locking pliers depicted
in
Fig. 16. In this embodiment, the locking pliers 146 have a central handle and
left and
right handles as described with reference to Fig. 16. The locking pliers 146
are also
provided with a pair of jaws 147,148, each of which include linear blade
portions. Jaws
147,148 are pivotally interconnected to the central handle by a common pivot
in 149 for
movement toward and away from one another. The linear blade portions of the
jaws
147,148 are suitable for cutting wires, cables, and the like, such as cable
150.
Fig. 23 shows a pair of locking pliers 151 similar to that depicted in Fig. 16
but
which is provided with a pair of arcuately curved jaws 152,153. The inner
surfaces of the
arcuately curved jaws are provided with toothed portions to enable a firm
gripping and
holding of workpieces having generally circular cross-sections, such as tube
154.
Although the invention has been described with reference to particular means,
materials, and embodiments, it is to be understood that the invention is not
limited to the
particulars disclosed and extends to all equivalence within the scope of the
claims.
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