Note: Descriptions are shown in the official language in which they were submitted.
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RA~ID JAW ADJUSTMENT FOR TOOLS AND THE LIKE
Backqround of The Invention
This invention relates to hand tools, and more particularly
to tools utilizing a pair of jaws for receiving a workpiece
therebetween.
Common elements of locking pliers, locking wrenches and
similar tools employing some form of locking toggle-actuation are
a pair of stationary and movable jaws adapted to lock a workpiece
therebetween. A mechanism with an adjusting element acting on the
movable jaw is usually provided to adjust a gap between the jaws
and to bring them into possible initial contact with a workpiece
before huge forces of the toggle action are generated and applied.
The tools of the type presently described are usually used in
the circumstances when fast and efficient adjustment of the gap
between the jaws is not only highly desirable but absolutely
necessary. One example of such use is a conveyor welding operation
where a welder has a very short time for adjustment of the tool
between welding together two separate pairs of elements having
different dimensions. In this situation, it is extremely important
to adjust the gap between the jaws of the locking tool to
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accommodate the dimensions of a new pair of elements as soon as
possible.
A known type of prior art device makes such adjustment of a
gap between the jaws by means of rotation of a single threaded,
single pitch adjustment screw to which the movable jaw is connected
directly or indirectly. This method and means of adjustment are
necessarily slow and time consuming and result in loss of valuable
time in adjusting the tools from one size to another.
8rief DescriPtion of The drawinqs
Other advantages and features of the invention are described
with reference to exemplary embodiments, which are intended to
explain and not to limit the invention, and are illustrated in the
drawings in which:
Fig. 1 is a side view of long-nose pliers utilizing the
invention.
Fig. 2 is a side, partial cross-section view of pliers having
curved jaws and utilizing the invention.
Fig. 3 is a partially, enlarged view of a threaded arrangement
shown in Figs. 1 and 2.
Fig. 4 is an end view of a screw member.
Fig. 5 is a partial cross-section view of threads of the screw
member.
Fig. 6 shows a partial view of a toggle-locking C-clamp.
Fig. 7 is a perspective view of a locking chain clamp.
Fig. 8 is a perspective view of a locking welding clamp.
Fig. 9 is a perspective view of a sheet metal tool.
DescriPtion Of The Preferred Embodiment
Although a specific embodiment of the invention will now be
described with reference to the drawings, it should be understood
that the embodiment shown is by way of example only and merely
illustrative of but one of the many possible specific embodiments
which can represent applications of the principles of the
invention. Various changes and modifications, obvious to one
skilled in the art to which the invention pertains, are deemed to
be within the spirit, scope and contemplation of the invention as
further defined in the appended claims.
As best shown in Fig. 1, the long-nose locking pliers is
generally designated by the reference numeral 10, and includes a
handle member 12, and a movable clamping member or lower jaw 14.
The handle member 12 is provided with a stationary clamping element
or upper jaw 16. A toggle mechanism comprises an elongated handle
member 18 and a toggle-link member 20 which is conventionally
pivotally engaged at one end about the pin 22. The other free end
(shown in phantom) of the toggle link member 20 is engaged with the
handle member 12, and in particular the abutment end (also shown
in phantom) of an adjustment screw member 24 which is suitably
threadably engaged at the end of the handle member 12. Operation
of the screw member will be discussed in full detail later in this
application. The forward end of the handle member 18 is preferably
bifurcated or forked, and a corner portion of the movable clamping
member 14 is suitably disposed within the fork or between the
bifurcation arms by pivot pin means 19. Similarly, the hand,e
member 12 is preferably channel-shaped, and receives another corner
portion of the movable clamping elemeni 14 which is also suitably
secured thereto by means of a pivot pin 17.
Spring means 25, preferably in the form of an extension coil
spring, is secured between the handle member 12 and the movable
clamping element 14 or lower jaw, to urge the clamping element 14
away from the stationary clamping element when the jaws are opened.
An elongated release lever 28 is suitably pivotally mounted
by means of a pin 30, to the inside of the handle member 18, and
is provided with a forwardly extending portion (as shown in
phantom) and is engageable with a projection 32 of the toggle-like
~ember 20 which extends toward the handle member 18. When the
release lever 28 is pivoted about the pin 30, the handle member 12
is moved away from the handle member 18.
It will be appreciated that the wrench or locking pliers
Dechanism and toggle construction described herein, with some
exceptions, conforms basically in accordance with the construction
described in U.S. Patent No. 1,489,458. Furthermore, such
construction, the operation thereof, and the specific operation of
the release lever is clearly set forth in U.S. Patent No.
3,192,804. As explained in these Petersen prior art patents,
closing of a locking wrench or pliers incorporating a toggle device
is effected by moving the relatively movable handle member 18
toward the relatively fixed handle member 12. This movement forces
the upper end of the toggle-like member 20 to move inwardly towards
the handle member 12. The pivot pin 22 also moves inwardly, and
when such pivot pin moves over center, the pliers is locked in a
closed position.
A tool of a further embodiment of the invention is best
illustrated in Fig. 2 and includes a fixed arm 15 having a fixed
handle 12 at one end and a fixed jaw 16 at the other end. A
movable jaw 14 is pivotally attached to a movable handle member 18.
The jaws 14 and 16, shown in Fig. 2, are curved and bulky. A
toggle-link member 20 is pivotally engaged with the movable handle.
The other free end 44 of the toggle-link engages with a contacting
part of a screw member 24. The fixed handle is suitably formed as
a U-shaped channel. The end of the fixed handle 30, remote from
the fixed jaw 16, is completed with a receiving portion 32 having
front 34 and rear 36 parts. A threaded opening 38 extends through
the receiving portion from the part 34 to part 36. A screw member
24 is provided for threadable engagement with the threaded opening.
The screw terminates in a knurled adjusting knob 40 at one end and
the contacting part 42 at the other end.
When the screw member 24 is turned at the knob by the user,
its rotation within the threaded opening results in advancement of
the screw in the axial direction. Such advancement in the
direction of the fixed jaw 16 presses the contacting part 42
against the toggle-link 20 and changes the distance between the end
o~ the toggle link 44 from the pivot point 17 of the movable jaw
16, whereby the distance between the stationary jaw 16 and the
movable jaw 14 is adjusted to grip objects of different dimensions
without exerting excessive force.
The screw member 24 and the threaded opening 38 are
illustrated in better detail in Fig. 3. A combined threaded part
44 of the screw member consists of two individual, separate and
coaxial threads 46 and 48 extending along a longitudinal axis A-A.
However, the screw member having any reasonable number of
individual threads is within the scope of the invention.
Since the pitches of the threads 46 and 48 shown in Figs. 3-
are identical, the distance between corresponding points on
adjacent turns of the thread 46 is equal to the distance between
corresponding points on adjacent turns of the thread 48.
Fig. 5 further illustrates that the crest and root diameters
of both threads are essentially the same.
To provide adequate threadable engagement between the screw
member 24 and the opening 38, the latter has a combined internal
thread consisting of two individual, separate and coaxial threads
50 and 52 adapted to threadably engage with the threads 46 and 48
of the screw member. The internal individual threads 50 and 52
extend through the length of the opening 38 from the front part of
the receiving portion 34 to the rear part 36.
In the preferred embodiment of the invention illustrated in
Fig. 4, two different starting points 54 and 56, at a specific
angle apart, are provided for the individual threads of the screw
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member. This is also applicable to the threaded opening. Although
such angle between two starting points could be of any reasonable
value, Fig. 4 illustrating an end vi~ew of the screw member of the
preferred embodiment shows such angle equal 180.
If the screw member is provided with three individual threads
the angle between adjacent starting points could be 120.
In order to prevent false starts when turning the screw member
into the threaded opening, an alternative embodi~ent (not shown on
the drawings) having a single initial or run-on turn is
contemplated by the invention. Thus, one thread of the screw
member makes initial mating engagement witn the corresponding
thread of the threaded opening at the beginning of the initial or
run-on thread turn of the threaded engagement. Similarly, the
second thread of the screw member makes initial mating engagement
with the corresponding thread on the threaded opening at the
beginning of the same initial or run-on turn. Therefore, only one
starting point for two threads is provided in such alternative
embodiment.
The threads of the invention could be metric as well as U.S.
Standard threads.
When a single threaded engagement between the screw member and
the threaded opening is used, as disclosed by the prior art, the
distance which the screw advances axially on one turn of the Xnob
is equal to the pitch of the single thread. On the contrary, if
the multiple threaded screw is used, as provided by the invention,
the axial advancement of the screw on one turn of the knob is equal
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to a combined pitch of all individual threads used. The screw
member 24 has two individual threads 46 and 48 having corresponding
pitches P1 and P2. When the user rotates the knob 40 one full
turn, the advancement of the screw in the axial direction is equal
to a combined pitch P1 and P2. Such double advancement by the
screw acting on the toggle link substantially increases the rate
of adjustment of the movable jaw relative to the stationary jaw.
Fig. 6 illustrates the arms of a toggle-locking C-clamp
wherein a fixed clamp member 51 is shown cooperating with a movable
clamp member 52, which pivots about the pin 53.
Fig. 7 shows a locking chain clamp, Fig. 8 shows a locking
welding ehain and Fig. 9 illustrates a conventional sheet metal
tool. All tools are well-known in the art and are incorporated by
reference.
The above-described arrangements for increasing the rate of
adjustment of the movable jaws or similar movable part can be
applied to the tools shown in Figs. 6-9.
The adjustment screw arrangement described hereinabove is also
applicable for Stilson wrenches, bench vises and other types of
tools.
