GB2115738A - Universal double-action circlip pliers - Google Patents

Abstract

The pliers comprise two handles (1, 2) pivotally connected to each other and carrying resiliently deflectable working jaws (9, 10) shaped to extend to a working plane, at least one of the jaws having a defector (12, 13) which enables the jaws to move past each other so that each jaw can be on one or the other side of the other jaw in the said working plane. <IMAGE>

Description

SPECIFICATION Circlip pliers The invention relates to pliers for cirolips, 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 compression, or 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 universality resulted in a design of pliers providing both functions by means of adding various adapters to these pliers.

Main drawbacks of the mentioned singlepurpose pliers reside in their limited applicability.

Hitherto known universal circlip pliers have their drawback in that their adaptation for individual functions takes much time and is tiresome, and without detailed operational instructions it is difficult to use them. These pliers function well for compression, but when adapted for opening, two hands must be used for 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 invention as claimed in the claims.

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 the opening mode thereof.

This is achieved without any auxiliary parts. Pliers according to the invention are simple, cheap and very reliable. The user needs only single pliers for both external and internal circlips. The position of the working jaws on the pliers is variable 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 the handling 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 exchangeable working jaws, the jaws may be made of an expensive high quality material which hardly affects the final price of the product, because a substantial part of the weight of the pliers is represented by the handles made of ordinary material without any special requirements on quality or heat treatment.

In order that the invention may be clearly understood and readily carried into effect, a preferred embodiment thereof is, by way of example, hereinafter more fully described and illustrated with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a plan view of pliers in their mode for opening circlips; Figure 2 is a plan view of the pliers in their mode for compressing circlips; Figure 3 is a side elevation of a detail of the handle ends provided with working jaws; Figure 4 is a plan view, from inside, of a handle in a dismantled 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 invention have handles 1 and 2 which cross each other and are pivotally connected by 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 will 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 1 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), preferably a torsion coil spring the arms of which extend into the respective grooves 7. The spring is pretensioned to urge the handles 1 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 fixed 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 11 and has a deflector which is, in the illustrated 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 movement of the pins 11. Although the cross-section shown in Fig. 5 is in the shape of an isosceles triangle, other shapes are suitable, such as circular or semicircular, elliptical or semi-elliptical diamondshaped 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 together, and an opening mode (Fig. 1) 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 Fig. 2 and the handles 1, 2 are gently pressed together the jaws 9, 10 get finally into a position in which their adjacent lateral surfaces 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 Fig. 1.

As is apparent from Figs. 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 is on the right. The movement of the handles 1 and 2 together is limited by the limiting projections 3 which are provided for safety reasons. The switching over from the opening mode to the compression mode is obtained 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 other. 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 fixing 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 movement need not be in the middle between the fixed ends as shown.

Claims (4)

1. 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 least one of the jaws having a deflector which enables the jaws to move past each other, so that each jaw can be on one or the other side of the other jaw in the said working plane.

2. Pliers according to Claim 1 wherein the working jaws are exchangeable.

3. Pliers according to Claim 1 or 2 wherein the working jaws are adjustable.

4. Pliers according to Claim 3 substantially as herein described with reference to, and as shown in, the accompanying drawings.