Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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The present invention relates to pliers for circlips,
and similar engineering components, herein described for use
with circlips and called ''circlip pliers'' for simplicity.
The removal and fitting of circlips is tiresome
and without special fixtures nearly impossible, For this
purpose pliers of various types are used. Widely used are
special single-purpose pliers working on the principle of
two levers connected pivotally either cross-wise for compres-
sion, o~ working on the principle of a double action lever
for opening. For both said functions, i.e. compression and
opening, two different pliers are needed-. Efforts for uni-
versali~ty resulted in a design of pliers providing both func-
tions by means of adding various adapters to these pliers.
Main drawbacks of the mentioned single-purpose
pliers reside in their limited applicability. Hitherto known
universal circlip pliers have their drawback in that their
adaptation for individual f-unctions takes much time and is
tiresome, and without detailed operational instructions it is
difficult to use them. These pliers function well for compres-
sion, but when adapted for opening, two hands must be usedfor the work with the pliers. The universality requires
other adapters for controlling their handles, which complicates
production and handling and increases production costs.
Besides that, working with these pliers is more complicated
than with single-purpose pliers.
The mentioned drawbacks may be obviated by
the universal double-action circlip pliers according to the
present invention.
According to the present invention there is
provided a circlip pliers comprising two handles pivotally
connected to each other and carrying working jaws shaped to
extend to a working plane of which at least one is resiliently
deflectable, at leàst one of the jaws having a deflector which
enable~ the jaws to move past each other, so that each jaw
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can be on one or the other side of the other jaw in the said
working plane.
Advantages of the pliers according to the invention
reside especially in an easy operation with the pliers and
easy switching from the compression mode to t~e opening mode
thereof. This is achieved without any a~xiliary parts. Pliers
according to the invention are simple, cheap and very reliable.
The user needs only single pliers for both extèrnal and in-
ternal circlips.
The position of the working jaws of the pliers is
preferably variable (adjustable and exchangeable) so that
the pliers may be used for various openings of circlips. Due
to the adjustability of the working jaws the pliers may be
used for a relatively large range of diameters of circlips.
As a consequence of the exchangeability of the working jaws
cranked working jaws may be used which enables thehandling of
circlips in holes. The user uses only one hand for working
with the pliers in both modes. The switching of the pliers
from one mode to another is instantaneous without any time
loss. Another advantage is that when the working jaws are
worn or damaged they may be replaced without the necessity
of replacing the whole pliers, as is the case with known
single-purpose pliers. Due to the small weight of the exchange-
able working jaws, the jaws may be made of an expensive high
quality material which hardly affects the final prlce of the
product,, because a substantial part of the welght of the
pliers is represented by the handles made of ordlnary materlal
without any special requirements on quality or heat treatment.
In order that the invention may be clearly under-
stood and readily carried lnto effect, a preferred embodimentthereof is, by way of example, hereinafter more fully described
and illustrated with reference to the accompanying diagram-
matic drawings, in which:-
Figure 1 is a plan view of pliers in their mode
A
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for opening circlips,
Figure 2 is a plan view of the pliers in their
mode for compressing circlips,,
Figure 3 is a side el~vation of a detail of the
handle ends provided with wor~ing jaws;
Figure 4 is a plan view, from inside, of a handle
in a d;s~ntled condition with a fixed working jaw; and
Figure 5 is a section of a working jaw along line
A-A in Fig. 4.
Universal double-action circlip pliers according
to the i.nvention have handles l and 2 which cross each other
and are pivotally connected ~y a pin 4. Jaw ends of the
handles are provided in the illustrated embodiment with three
spaced apart fixing holes 6 each. The fixing holes 6 are
situated on an imaginary circular arc the centre of which is
in the axis of the pin 4. It wil',L be understood that one
fixing hole 6 is sufficient, and if more than one fixing
hole are used they may be arranged in a manner different to
that described in connection with the illustrated embodiment.
The inner part of the handles l and 2 around the
pin 4 is recessed whereby: a spring chamber 8 is provided
(Fig. 3) and in each handle is a groove 7 ~Fig. 4) extending
from the spring chamber 8. Situated in the chamber 8 and slid
on the pin 4 is a spring (not shown), prefe~ably a torsion
coil spring the a.rms of which extend into the respective
grooves 7. The spring is pretensioned to urge the handles l
and 2 away from each other.
Working jaws 9 and 10 are carried by the jaw ends
of the handles 1 and 2, respectively. One end of each jaw
is fixetl to the respective handle 1,2 by the pin 4 and its
middle part is fixed by a fixing screw 5 which is received
in a selected one of the fixing holes 6.
The free end of each working jaw 9 and 10 carries
a working pin ll and has a deflector which is, in the illustrated
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embodiment, substantially triangular in cross-section (Fig. 5)
so that it has two planar inclined lateral surfaces 13, which
extend inwardly of the jaw and meet at a ridge 12. The free
ends are resilient and are shaped so that they end in a plane
passing between the fixed ends, which is the plane of the
working ~v'~ ~nt of the pins 11. Although the cross-section
shown in Figure 5 is in the shape of an isosceles triangle,
other shapes are suitable, such as circular or semi-circular,
elliptical or semi-elliptical diamond-shaped or trapezial.
The circlip pliers according to the invention can
operate in two modes, namely a compression mode (Fig. 2) in
which they are used to press the ends of an internal circlip
toge$her, and an opening mode (Fig. l) in which it is used to
force the ends of an external circlip from each other. In
both these modes the handles 1 and 2 are pressed together.
When the pliers are in the compression mode shown in Figure
2 and the handles 1,2 are gently pressed together the jaws
9,10 get finally into a position in which their adjacent
lateral s~rfaces 13 bear on to each other and prevent further
movement. If in this position the handles 1 and 2 are pressed
together more firmly the inclined lateral surfaces 13 slide
on each other and deflect the pins 11 from the said working
plane, the maximum deflection being obtained when the ridges
12 are in contact with each other. When the ridges 12 move
past each other, on further compression of the handles 1 and
2, the pliers get into the opening mode shown in Figure 1.
As is apparent from Figures 1 and 2 in both modes the handle
1 is on the left and the handle 2 is on the right, while in
the compression mode the jaw 9 is on the right and the jaw
10 is on the left, whereas in the opening mode the jaw 9 is
on the left and the jaw 10 ison the right. The -,v~ ?nt of
the handles 1 and 2 together is limited by the limiting pro]ec-
tions 3 which are provided for safety reasons. The switching
over from the opening mode to the compression mode is obtained
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in the same way when the handles 1 and 2 are moved away from
each other.
The fixing holes 6 enable readjustment of the working
jaws 9 and 10 so that they are in the maximum closing position
of the handles 1 and 2 at a selected distance from each othex.
In this way the pliers are adapted for use with circlips of
various sizes.
It will be understood that many modifications of the
illustrated and described embodiment are possible. So, for
instance, the jaws 9,10, or at least one of them, may have
their fixed end fixed e.g. by a ixing screw (similar to 5)
in a fixing hole or one of a fixing holes (similar to 6). And
it is sufficient if only one jaw, or the free end or a part
; of the free end is resilient, or resiliently mounted to enable
the described deflection. Also the plane of the working move-
ment need not be in the middle between the fixed ends as shown.
