WO2002032600A1

WO2002032600A1 - Wire joining tool

Info

Publication number: WO2002032600A1
Application number: PCT/GB2000/004070
Authority: WO
Inventors: Jonathan Armitage; Roger Bernard John
Original assignee: Jonathan Armitage; Roger Bernard John
Priority date: 2000-10-21
Filing date: 2000-10-23
Publication date: 2002-04-25
Also published as: AU2001210389A1; GB2370330A; GB0025860D0

Abstract

A method and apparatus for joining together two or more overlapping lengths of wire by preventing the wires from rotating about one another at each of two spaced-apart points along their overlapping portion whilst, at the same time, twisting the wires about one another between said two spaced-apart points to form a joint. The joint thus formed is highly resilient, having a tensional strength approaching that of the wires that are joined together. Furthermore, when used to join together a pair of electrical conductors, the joint is not prone to the types of fatigue associated with existing joints, which can result in failure of the electrical connection.

Description

Wire Joining Tool

The present invention relates to a tool for joining together wires.

A number of tasks require two or more wires to be securely joined together, typical examples being the joining together of successive lengths of wire to form a fence or the joining together of two wires to form an electrical connection.

We have now devised a simple yet highly effective tool for joining together two or more overlapping lengths of wire.

In accordance with the present invention, there is provided a tool for joining together two or more overlapping lengths of wire, the tool comprising means for preventing the wires from rotating about one another at each of two spaced- apart points along their overlapping portion and means for twisting the wires about one another between said two spaced- apart points to form a joint.

We have found that the joint formed by such a tool is highly resilient, having a tensional strength approaching that of the wires that are joined together. Furthermore, when used to join together a pair of electrical conductors, we have found that the joint is not prone to the types of fatigue associated with existing joints, which can result in failure of the electrical connection.

Preferably the means for preventing the wires from rotating about one another at each of said spaced-apart points comprises means for preventing the wires from rotating about their respective axes at those points and/or for preventing inwards axial movement of the wires towards the joint as they are twisted about one another. We have found that such an arrangement substantially increases the strength and resilience of the joint formed by the tool.

Preferably the means for twisting the wires about one another comprise means for preventing the wires from rotating about their respective axes at the point along their overlapping length at which the wires are engaged to twist them about one another. We have found that such an arrangement also substantially increases the strength and resilience of the joint formed by the tool.

In a preferred embodiment of the present invention, the means for twisting the wires about one another comprises a rotatable wheel arranged for the wires to extend through its axis of rotation between opposed surfaces which rotate with the wheel, the distance between the opposed surfaces being at least equal to the diameter of the thickest of the wires to be joined together but less that the sum of the diameters of the thickest and the thinnest of the wires to be joined together, so that the wires will be engaged by the opposed surfaces as the wheel is rotated.

The opposed surfaces may be a fixed distance apart. For example the opposed surfaces may be provided by the sides of an aperture formed through the axis of rotation of the wheel. However, to prevent the wires from rotating about their respective axes at their point of engagement, the opposed surfaces are more preferably provided by the opposed surfaces of a pair of jaws which are mounted to the wheel and between which the wires are clamped as the wheel is rotated.

Preferably the jaws are pivotally mounted for rotation about respective axes extending either side of and in parallel with the axis of rotation of the wheel and are arranged such that as the wheel is rotated to twist the wires about one another, interference between the opposed surfaces of the jaws and the wires causes the jaws to rotate about their respective axes with respect to one another, to reduce the gap between them.

Preferably the jaws are biassed to minimise the gap between them, such that the opposed surfaces of the jaws are continually held in contact with the wires which extend between them.

The wheel may be rotated by any convenient means, but is preferably rotated by a ratchet mechanism comprising a reciprocating pawl which meshes with teeth formed on the wheel to incrementally rotate the wheel in one direction only and a catch which engages the wheel at discrete angles of rotation to prevent the wheel from rotating in the opposite direction.

Also in accordance with the present invention, there is provided a method for joining together two or more overlapping lengths of wire by preventing the wires from rotating about one another at each of two spaced-apart points along their overlapping portion whilst, at the same time, twisting the wires about one another between said two spaced-apart points to form a joint.

Preferably the wires are prevented from rotating about their respective axes at each of said spaced-apart points.

Preferably the wires are prevented from moving axially inwards towards the joint at each of said spaced-apart points. Preferably the wires are prevented from rotating about their respective axes at the point along their overlapping length at which they are engaged to twist them about one another.

Further in accordance with the present invention, there is provided a clamp comprising a pair of opposed jaws arranged to receive an elongate member therebetween, the jaws being pivotally mounted for rotation about respective axes extending either side of and in parallel with the axis of the elongate member, such that interference between the surfaces of the jaws and the elongate member, as the jaws are rotated about the axis of the elongate member, will cause the jaws to rotate with respect to one another to reduce the gap between them.

An embodiment of the present invention will now be described by way of an example only and with reference to the accompanying drawings, in which:

Figure 1 is an isometric view of a wire-joining tool in accordance with the present invention; Figures 2 and 3 are side elevations of the tool at different stages of operation;

Figure 4 is a cut-away side elevation of the tool; Figure 5 is a cut-away isometric view of the tool; Figure 6 is a cut-away isometric view of the tool from the opposite side;

Figure 7 is a series of diagrams illustrating the sequence of operation of the ratchet mechanism of the tool; and

Figure 8 is a series of diagrams illustrating the sequence of operation of the wire-clamping mechanism of the tool.

Referring to Figure 1 of the drawings, a tool is shown comprising a pair of handles 2,4 which are pivotally joined to one another at a substantially cylindrical hub 6, the components of the hub 6 being arranged to provide a radial slot 8 into which two wires may be inserted such that the wires extend axially through the centre of the hub 6.

Further handles 14,16 on either side of the hub 6 are arranged to pivot about the ends of respective connecting brackets 18,20, as shown in Figures 2 and 3, to crimp the overlapping portions of the wires which extend axially from either side of the hub 6, within the gap provided between the hooked ends 22,24 of wire loops 26,28 connected to the handles 14,16 and adjacent upright portions 30,32 of the connecting brackets 18,20. The wire loops 26,28 are resiliently deformable to allow their hooked ends 22,24 to splay apart according to the thickness and thus the radius of curvature of the wires that they are used to clamp.

The hub 6 comprises opposed shell, portions 34,36 which are joined together by a plurality of connecting bolts 38 to form a housing for the proximal ends 40,42 of the handles 2,4 and for a rotatable core 44.

Referring to Figures 4 and 5, in which one shell portion 34 of the hub 6 has been omitted, the proximal end 40 of handle 2 can be seen to be substantially crescent shaped and formed with a pair of lugs 48,50 which engage within respective recesses 52,54 formed in the shell portions 34,36 to fix the position of handle 2 with respect to the hub 6. The distal end of the crescent shaped end portion 40 of handle 2 is bifurcated and aligned with corresponding cut-outs 56,58 formed in opposed edges of the shell portions 34,36 to provide an elongate slot 60 within which the shank 62 of handle 4 may be slid backwards and forwards to rotate the cylindrical end portion 42 of Handle 4, in opposite directions, within the hub 6.

The rotatable core 44 of the hub 6 comprises a pair of slotted discs 66,68 between which a pair of jaws 70,72 are rotatably mounted to respective axles 74,76, for gripping wires extending through the axis of the core 44, the precise arrangement of the jaws 70,72 being shown in Figure 6 in which the slotted discs have been omitted.

Referring again to Figures 4 and 5, respective plates 78,80 fixed to the outer surfaces of the discs 66,68 are each formed with four toothed regions 82,84,86,88, one toothed region 88 being radially inset from the others.

On either side of the core 44, a respective toothed pawl 90,92 is pivotally mounted to the cylindrical end portion 42 of the handle 4, the distal end of each pawl 90,92 being biassed towards the opposed circumferential edge of its adjacent toothed plate 78,80. Thus, when appropriately aligned, the teeth of each pawl 90,92 will mesh with one or other of the toothed regions 82,84,86,88 of its adjacent plate 78,80 to provide purchase on the core 44, for rotating the core 44 about its axis .

Thus, as shown in the sequence of drawings of Figure 7, the core 44 of the hub 6 may be rotated about its axis in four successive angular increments, shown respectively in Figures 7d, 7f, 7h and 7j , by repeatedly separating and then bringing together the handles 2,4, the pawls 90,92 being advanced between successive toothed regions 82,84,86,88 of the plates 78,80, each time the handles 2,4 are brought together. At 90°, 180° and 270° increments, as shown in Figures 7d, 7f and 7h respectively, a radially projecting portion 94 of each pawl 90,92 butts against a respective stop 96, thereby limiting the extent to which the handles 2,4 may be brought together. However, in meshing with the radially inset series of teeth 88 to rotate the core 44 beyond 270°, the distal ends of the pawls 90,92 are inwardly displaced, so that on the final turn of the core 44, the handles 2,4 can be fully closed to rotate the core 44 beyond 360° , thereby over-tensioning the wires held between its jaws. As the core 44 is rotated, a pair of pivoting catches 98,100 mounted at 90°, to one another on either side of the core 44 alternately engage one or other of a pair of stops 102,104 which project from each side of the core 44. This arrangement limits the extent to which the core 44 can rotate backwards about its axis, due to the recoil action of the tensioned wires, each time the pawls 90,92 are released from the teeth 82,84,86,88 of the plates 78,80, to be advanced around the core 44. The stops 102,104 are arranged such that the core 44 is held in place at 90°, 180°, 270° and 360° of rotation within the hub 6. Thus, when the handles 2,4 are separated from one another after the final turn of the core 44, the core 44 is free to rotate backwards through a small angle as tension in the wires is released. Referring to Figure 8a, the two jaws 70,72 are connected to one another by a swinging coupling 106, one end of which is also attached by a spring 108 to a projecting portion of jaw 70, such that the opposed surfaces of the jaws 70,72 are continually biassed towards one another and thus into contact with wires 110,112 extending between them.

The sequence of drawings of Figure 8 show how, as the core 44 is rotated in successive angular increments about its axis within the hub 6, interference between the opposed surfaces of the jaws 70,72 and the wires 110,112 extending between them will cause the jaws 70,72 to rotate in opposite directions about their respective axles 74,76. The jaws 70,72 are shaped such that as they rotate about their respective axles 74,76, the gap between their opposed surfaces is reduced, thereby clamping the wires 110,112 in place to prevent them from rotating about one another and about their respective axes .

Figures 8f and 8g correspond with Figures 7j and 7k and show how, as the over-tensioned wires 110,112 recoil to reverse the direction of rotation of the core 44, interference between the opposed surfaces of the jaws 70,72 and the wires 110,112 will rotate the jaws about their respective axles 74,76 to release the clamping pressure on the wires 110,112 so that they may be extracted from the slot 8 of the hub 6. The tool thus described provides a simple yet highly effective means for joining together two or more overlapping lengths of wire.

Claims

Claims .

1) A tool for joining together two or more overlapping lengths of wire, the tool comprising means for preventing the wires from rotating about one another at each of two spaced- apart points along their overlapping portion and means for twisting the wires about one another between said two spaced- apart points to form a joint.

2) A tool as claimed in Claim 1, wherein the means for preventing the wires from rotating about one another at each of said spaced-apart points comprises means for preventing the wires from rotating about their respective axes at those points as they are twisted about one another.

3) A tool as claimed in Claim 1 or Claim 2, wherein the means for preventing the wires from rotating about one another at each of said spaced-apart points comprises means for preventing inwards axial movement of the wires towards the joint as they are twisted about one another.

4) A tool as claimed in any preceding claim, wherein the means for twisting the wires about one another comprise means for preventing the wires from rotating about their respective axes at the point along their overlapping length at which the wires are engaged to twist them about one another.

5) A tool as claimed in any preceding claim, wherein the means for twisting the wires about one another comprises a rotatable wheel arranged for the wires to extend through its axis of rotation between opposed surfaces which rotate with the wheel, the distance between the opposed surfaces being at least equal to the diameter of the thickest of the wires to be joined together but less that the sum of the diameters of the thickest and the thinnest of the wires to be joined together, so that the wires will be engaged by the opposed surfaces as the wheel is rotated.

6) A tool as claimed in Claim 5, wherein said opposed surfaces are a fixed distance apart.

7) A tool as claimed in Claim 6, wherein said opposed surfaces are provided by the sides of an aperture formed through the axis of rotation of the wheel.

8) A tool as claimed in Claim 5, as appended to Claim 4, wherein said opposed surfaces are provided by the opposed surfaces of a pair of jaws which are mounted to the wheel and between which the wires are clamped as the wheel is rotated.

9) A tool as claimed in Claim 8, wherein the jaws are pivotally mounted for rotation about respective axes extending either side of and in parallel with the axis of rotation of the wheel and are arranged such that as the wheel is rotated to twist the wires about one another, interference between the opposed surfaces of the jaws and the wires causes the jaws to rotate about their respective axes with respect to one another, to reduce the gap between them.

10) A tool as claimed in Claim 8 or Claim 9, wherein the jaws are biassed to minimise the gap between them, such that the opposed surfaces of the jaws are continually held in contact with the wires which extend between them.

11) A tool as claimed in any of Claims 5 to 10, wherein the wheel is rotated by a ratchet mechanism comprising a reciprocating pawl which meshes with teeth formed on the wheel to incrementally rotate the wheel in one direction only and a catch which engages the wheel at discrete angles of rotation to prevent the wheel from rotating in the opposite direction.

12) A method for joining together two or more overlapping lengths of wire by preventing the wires from rotating about one another at each of two spaced-apart points along their overlapping portion whilst, at the same time, twisting the wires about one another between said two spaced-apart points to form a joint.

13) A method as claimed in Claim 12, wherein the wires are prevented from rotating about their respective axes at each of said spaced-apart points.

14) A method as claimed in Claim 12 or Claim 13, wherein the wires are prevented from moving axially inwards towards the joint at each of said spaced-apart points.

15) A method as claimed in any of Claims 12 to 14, wherein the wires are prevented from rotating about their respective axes at the point along their overlapping length at which they are engaged to twist them about one another.

16) A clamp comprising a pair of opposed jaws arranged to receive an elongate member therebetween, the jaws being pivotally mounted for rotation about respective axes extending either side of and in parallel with the axis of the elongate member, such that interference between the surfaces of the jaws and the elongate member, as the jaws are rotated about the axis of the elongate member, will cause the jaws to rotate with respect to one another to reduce the gap between them.