WIRE CRIMPING TOOL

(2) BACKGROUND TO THE INVENTION

The pinching of flexible piping onto a rigid tube by way of a length of loop formed wire is conventionally done with the aid of a pair of pliers. The extent of tensioning is during such a process determined by the twisting action applied by the pair of pliers at the location of wire crossover loop closure. As the extent of pinching is on using such method mainly dependent of the twisting action applied to the wire, often requiring a substantial number of wire convolutions, the action can easily give rise to wire severing in the process of convolution formation. Even if the tensioning effect is achieved with the use of equipment that exert a tangential force on wire ends extending from a loop formation formed along a section of wire the application of force is still mainly concentrated at the point of wire crossover having generally the same effect as discussed above in relation to the use of a pair of pliers. A two step operation may even be required in adjusting the position of anchoring of wire ends to attaint a sufficient pinching effect. The achievement of a successful pinching or crimping effect under the above and other circumstances becomes more difficult the larger the wire diameter gets. It is, amongst others, an object of this invention to provide equipment that addresses the above drawbacks.

(3) FIELD OF THE INVENTION

This invention relates to a manually operable wire tensioning tool for amongst others pinching flexible piping onto rigid tubing by way of a length of wire or the like.

(4) PRIOR ART DESCRIPTION

In the prior art, according to the knowledge of the inventor and applicant, the loop formation type tensioning of wire onto a location of wire crimping is often done by way of a pair of pliers. Equipment that exerts a tangential force on wire ends extending from a loop formation formed along a section of wire is also known to the applicant and inventor. Both of the methods used in the prior art have the drawbacks discussed under the background to the invention.

(5) BRIEF DESCRIPTION OF THE DRAWING

The invention is now described, by way of example, with reference to the accompanying drawings. In the drawings Figure 1 three dimensionally shows a manually operable wire tensioning tool in the form of a wire crimping tool,

Figure 2 shows the tool in side elevation,

Figure 3 shows the tool in end view, and

Figure 4 shows the stepwise operation of the tool.

(6) DETAILED DESCRIPTION OF THE DRAWINGS

Referring to the drawings a manually handlable and operable wire-tensioning tool in the form of a wire-crimping tool is generally indicated by reference numeral 10.

The tool 10 comprises a manually manipulate wire tensioning mechanism in the form of two displaceable members as provided by two arms 12 that extend from and are swivellably interconnected by way of a head 14 that is constituted from arm leading end formations 16, and wire end anchoring locations that are associated with the arms 12 in the form of a bore 18 through the one arm 12.1 and a peg 20 extending from the other arm 12.2. The formations 16 are integrally formed with their respective arms 12 in forming tool-constituting _r members 22 of which the swivellable interconnection give rise to the tool 10.

The leading end formations 16 are each in the form of a leading end disk type section 24 that extends from a root portion 26 from the centre of which its arm 12 trailingly extends. The sections 24 lie laterally against one another in each forming one half of the width 28 of the head 14. The axis 30 of arm inter-swivelling passes through the centres of the sections 24. While extending the full width 28 of the head 14 the root portions 26 each only extends half the breadth 32 of the head 14 thus serving a stop function on closure of the arms 12 into their tool closure condition in which the arms 12 lie adjacent one another, as shown in figures 1 and 2. In extending centrally from their respective root portions 26 the arms 12 are swivellable along a common plane that extends through the central axis 34 of the tool 10 and the arms 12 consequently ensuring pliers type tool operation. When fitted with wire and the tool 10 is displaced to its tool arm closure condition (figures 1 and 2) such wire is also generally displaced in the direction of the head 14 along generally the common plane as extending through the central axis 34.

The sections 24 are formed with remote edge lateral flanges 36 defining an intermediate wire retention zone 38 for holding a length of wire against slipping from the head 14 once the tool 10 is in operative use, as discussed below. Being swivellably interconnected by way of leading end disk sections 24 the members 22 are swivelable relative to one another along arcs extending between the condition of tool closure and a condition of tool wire anchoring, as shown in figure 4(a), in which the arms 12 are swivelled beyond their condition of full outward flaring with respect to one another in relation to the condition of tool closure. The nose part 40 of the head 14 defines a location of tensioning mechanism operation non-interference onto which a location of wire loop crimping, in pinching flexible piping fitted onto tubing, is pulled up against on the

performance of a tensioning operation by way of the tool 10, as discussed below.

To facilitate the trimming of wire ends once a tensioning and pinching action has been performed and the tool 10 has been released from the wire the disk sections 24 are each formed with one or more lateral grooves 42. The grooves 42 are pliers wire cutting type action used to trim undesired wire lengths extending beyond a location of twisted wire loop locking by simply positioning an appropriate location along such wire along aligned grooves 42. A wire cutting action is achieved by simply swivelling the members 22 in opposite directions causing the grooves 42 to move out of alignment in turn snipping the wire at the location of groove discontinuation.

The spacing between the root portions 26 can furthermore be used as a location of wire pinching for use in exerting a strong pull on wire for some or other reason. Being in close proximity to the axis 30 a very strong grip can naturally be exerted on wire so pinched.

Although not shown the free ends of the arms 12 can be formed with bores though which wire can be threaded for performing a general wire tensioning action.

In use the initial step in preparing a length of wire for use in performing a wire type crimping action on flexible piping fitted onto rigid tubing by way of length of wire is to fit a pre-selected length of wire about the location of intended crimping to form a pre-shaped the loop. The loop is preferably formed substantially centrally along the length of wire.

In referring more particularly to figure 4 the length of wire 44 as formed with an intermediate loop 46 is thus fitted between the arms 12 as swivelled to their condition of tool wire anchoring as shown in figure 4(a). To this effect the one end section 44.1 of the length of wire 44 is threaded through the bore 18 in the arm 12.2 and subsequently wrapped around this arm to firmly anchor this end of the length of wire 44 to the tool 10. Subsequently the other end section 44.2 is turned onto the peg 20 and also onto the arm 12.1 , as shown in figure 4(b) though in a way that retains the size of the loop 46 owing to fitting the wire in a non-tensioned way between the arms 12. As also shown in figure 4(b) tubing 48 as fitted with flexible piping 50 is threaded through the loop 46 centring the location of intended crimping within the loop 46.

The crimping action commences by urging the arms 12 in the directions of arrows 52 and thus towards the tool closure condition. In the process the location of intended crimping is at first pulled onto the nose part 40 of the head 14, as shown in figure 4(c), where after the loop 46 becomes progressively tensioned onto the location of crimping in the process pinching the piping 48 onto the tubing 50, as shown in figure 4(d).

Once an adequate extent of crimping is attained the loop 46 is closed off by simply twisting the tool 10 as in its figure 4(d) condition and the piping as now crimped onto the tubing through half a circle or more relative to one another creating a location of loop lockage as formed by the twisted wiring at their point of crossover. It will be appreciated that wiring of adequate tensile strength is required when only half a turn is adequate to achieve the required loop locking effect.

Removal of the tool 10 involves the untying of the wire ends 44.1 and 44.2 from their respective arms 12. Unwanted wire end lengths are trimmed away by the pliers cutting type action in involving the grooves 42.

Some advantages of the invention as specifically described are found in the tensioning action of the tool taking place in close proximity to the pivot point of the arms giving substantial leverage. As the exertion of a tensioning force takes place prior to forming wire crossover on loop closure the force is evenly exerted along a large extent of the

circumference subjected to a crimping action. While the range of displacement of the arms between their condition of tool wire anchoring and tool closure is extensive a crimping operation can take place by way of a one step procedure. The locations of anchoring of wire to the arms of the tool further enables the use of wire of larger thickness naturally giving a stronger pinching effect in performing a crimping action. Being of lightweight constitution the tool is used with ease.