GB2311664A

GB2311664A - Wedge connector for joining wires and cables

Info

Publication number: GB2311664A
Application number: GB9706228A
Authority: GB
Inventors: Jack Taylor
Original assignee: TREND INSTALLATION TOOLING LIM
Current assignee: TREND INSTALLATION TOOLING LIM
Priority date: 1996-03-26
Filing date: 1997-03-26
Publication date: 1997-10-01
Anticipated expiration: 2017-03-26
Also published as: GB9706228D0; GB2311664B; GB9606352D0

Description

Title: Improvements in connectors for wires, cables, cords and the like DESCRIPTION This invention relates to an improved type of connector for lengths of wire, cable, cord or the like, particularly being suitable for connecting conductors, such as electricity cables and optical fibres.

Lengths of rope, cord, wire and cable are used in a wide variety of applications such as for fencing, electricity cables, communication systems and so on.

All these applications require the connection of individual lengths of material in a manner that will not readily allow the lengths to come apart.

Electrical conductors, such as electricity cables are frequently joined between overhead pylons, run underground and/or are attached to buildings and structures.

The lines of cable have to be connected together using a constant pressure design such that a satisfactory connection is established between the cables. A vast number of electricity and fibre optic wires and cables are employed all over the world in order to supply electricity and communication systems over a large network. This requires the efficient connection of the lines of cables and/or wires to each other, preferably by means of the simplest and cheapest mechanism possible.

Prior hereto, electricity cables and the like have generally been joined by means of one of two types of connector. Compression fittings may be used to join cables or wires by crimping the connectors onto the cables using hydraulic tools. The component makes a connection by deformation of the barrel around the conductor.

This type of connector does perform well but the high cost of the crimping tools and dies results in the installation of such connectors being expensive. Additionally, the weight of the crimping tool and the physical power needed to perform the series of crimping operations during installation is undesirable, especially given the often cramped conditions and dangerous locations of, for example, underground or overhead power cables.

The second type of known connector consists of a wedge which is fired from cartridges between cables in a tapered body. This requires percussion tooling which is expensive. The installation of the connector is also difficult, particularly in hazardous locations, for example, when mending overhead power cables after damage by adverse weather conditions. Furthermore, the percussion tooling employed for installing the connector is difficult to export to foreign countries due to firearm regulations.

It is an object of the present invention to provide a connector for joining cables, wires, cords and the like, particularly those in the form of conductors, which is cheap and easy to manufacture.

It is a further object of the invention to provide a connector which may be quickly and easily installed, thereby obviating the need for complex compression or percussion tooling, torque wrench settings and shear head bolts.

Yet a further object of the present invention is to provide a connector which may be adapted to suit a wide range of cables and wires and which may be released and reused.

Accordingly, the present invention provides a connector for joining lengths of wire and the like, comprising a casing for receiving the wires in a spaced side by side arrangement and a cam for placing between the wires, whereby rotation of the cam in a plane through the wires exerts a force on each wire to secure the same against opposing walls of the casing.

In the context of this disclosure, the term "wire" is intended to include any length of material in the form of a cable, cord, fibre, filament, rope, wire, string or otherwise.

Preferably, the casing comprises a base having side walls at either end thereof, the walls preferably being arcuate. The casing is preferably C-shaped in cross section, whereby the wires may be placed respectively against opposite side walls thereof. It is preferable that each of the arcuate side walls of the casing is provided with a flange which extends inwardly to cover at least a part of the wire.

Alternatively, the casing may be oval in cross-section to provide an enclosed unit around the wires. The cam and wires may be inserted into the casing through the openings at either end of the casing or a hole may be provided in the roof or base of the casing for insertion of the cam. It is to be appreciated that the hole would be of a size and shape suitable to enable the cam to be fitted therethrough into the body of the casing.

The casing may also be provided with one or more bolt holes to enable securement of the connector to a structure or building. Preferably, the bolt holes are provided in the base and/or roof of the casing. The casing may be made of any suitable material but, preferably is made of the same material as the cam.

The cam may be produced in a variety of shapes and sizes depending upon the size and shape of the wires to be connected thereby and the casing into which it is to be fitted. However, preferably the cam is generally hexagonal in shape, more preferably being in the form of an elongated hexagon. Alternatively, the cam may be oval in shape. It is also preferable that the cam be formed with concave sides for surrounding a part of the wire. The cam has a self-locking mechanism whereby movement of the wires through the connector causes the cam to rotate and tighten the connection. Further means may be provided to lock the connector, if required, such as a ratchet mechanism in which the sides of the cam are provided with teeth to grip the wires thereby preventing the movement of the cam once it has been rotated to the required degree.

Preferably, the cam is provided with a bore, slot or recess to receive means for rotation of the cam. The bore, slot or recess may be of any suitable size or shape but preferably is square or hexagonal in cross section and is preferably positioned through or in the centre of the cam.

Any suitable means may be employed to rotate the cam. For example, a Tshaped lever may be used whereby the stalk of the lever is placed in the bore, slot or recess of the cam and the bar is turned to cause rotation of the cam. The lever may be manually-operated or power-operated. Alternatively, the cam may be rotated using a screw mechanism.

Preferably, the casing is also provided with a bore, slot or recess preferably through or in the centre thereof to assist in locating the cam between the wires.

It is preferable that a type of key is used to position and rotate the cam in the casing thereby securing the wires in position. The key preferably comprises, in the given order, a spigot, a square block section and a T-shaped section. The cam is placed over the spigot onto the surface of the square block section and placed into the casing. The spigot of the key is fitted into the bore, slot or recess of the casing thereby locating the cam in the correct position. The T-section of the key may then be used to rotate the cam such that the wires are held firmly in position.

It is preferable that a cam having a recess for introduction of the spigot or stalk of the rotating means is provided with a locating spigot protruding from the opposite surface thereof to assist in placing the cam in the correct position in the casing. Alternatively, the locating spigot may protrude from the base of the casing to mate with a recess, slot or bore provided in the cam.

It is to be appreciated that the cam may also be provided with a spigot protruding from the surface thereof for gripping means to rotate the cam, such as a spanner or the like, as an alternative to a bore, slot or recess for receiving means for rotation of the cam.

The connector of the present invention may be used to connect a wide range of wires including cables, cords, rope, string, fibres or the like. Preferably, the connectors of the present invention are used to join conductors. In the context of this disclosure, the term "conductor" is intended to include any material which transmits energy or matter, especially electricity, heat, light or sound.

For electrical connections, the cam may be made of any electrically conducting material to allow an electrical connection to be made between the conducting wires.

The preferred material of the cam is aluminium. However, examples of other suitable conducting materials are copper, steel, stainless steel, gunmetal or bronze. If the cam is made of an alloy, the alloy preferably contains at least 30% copper, ideally at least 50%. A steel cam is preferably provided with an electroplated coating of zinc or nickel and chromium, the zinc coating preferably having a thickness of at least 5calm and the nickel and chromium coating preferably being at least 20 zm in thickness.

Stranded or solid cables of, for example, copper or aluminium may be connected by means of the present invention, which may be non-insulated, paperinsulated or polymeric-insulated. The conductors may be plain or may be metal coated, for example, annealed copper coated with a thin layer of tin, tin alloy or lead alloy. Conducting materials other than electrical conductors may also be connected by means of the present invention. Indeed, the connector is suitable for almost any mechanical or earth rod/lightning conductor connector, for example fibre optic cables.

The earthing of the fibre optic cables would be used to form the connection.

The casing is preferably extruded as a continuous piece which is subsequently cut into sections. Holes may then be pierced or drilled through the casing as required. The cam may be formed using, for example, a cast or by forging into the required shape.

For a better understanding of the present invention and to show more clearly how it may be carried into effect, reference will now be made by way of example only to the accompanying drawings in which: Figure 1 is a perspective view of a connector according to one embodiment of the present invention connecting two, parallel cables.

Figure 2 is a perspective diagram of the casing of the connector shown in Figure 1; Figure 3a is a perspective view of the cam of the connector shown in Figure 1; Figure 3b is a cross-sectional view of a cam according to a different embodiment of the present invention; Figure 4 is a plan view of the casing and cam shown in Figures 2 and 3a fitted together to connect two cables; Figure 5 is a cross-sectional view of a connector according to another embodiment of the present invention; Figure 6 is a cross-sectional view of a connector according to yet a further embodiment of the present invention; Figures 7a to 7g illustrate the installation of the connector shown in Figure 1; Figure 8 is a schematic diagram of a service or branch connector; and Figure 9 is a schematic diagram of a through connector or conductor terminator.

Referring to Figures 1 to 4 of the accompanying drawings, a preferred embodiment of a connector according to the present invention is illustrated. The connector 1 comprises a casing 2 and a cam 4. The cables 8 are positioned at respective sides of the casing and are held in place by the cam 4 rotatably secured between the cables 8 to form a mechanical connection.

The casing 2 comprises a parallel section having a flat base 12 with arcuate side walls 14 such that, in cross section, the casing forms generally the shape of a C (see Figure 2). The tops of the side walls 14 preferably extend inwards to form a flange 18. The base 12 has a hole 22 drilled or pierced through the central region thereof and may be provided with one or more bolt holes 24 to allow securement of the casing to a building or structure. However, it is to be appreciated that the casing may of a different shape to that illustrated herein. For example, the casing may be oval in cross-section to form an enclosed unit around the cables and the cam, the cam being inserted through the openings at either end of the casing or through a hole provided in the roof thereof.

The cam 4, which may be forged or cast, is generally an elongated hexagon in shape having concave side walls 32 and a bore 34 through its centre (see Figure 3a) to receive means for rotation of the cam. The elongated hexagonal shape of the cam allows the cam to placed between the cables in the casing by orientating the cam such that the section of shorter diameter (shown by line "a" in Figure 4) lies along the cables. The cam is then rotated to result in the section of greater diameter (shown by line "b" in Figure 4) being forced against the cables thereby pushing the cables against the walls of the casing to form a mechanical connection. Hence, the dimensions of the cam will depend upon the particular size of the cables and casing in use. The concave side walls are such that they correspond to the profile of the cable that is held in the connector. However, it is to be appreciated that the cam is not limited to the particular embodiment described and may be made in a variety of different shapes and sizes depending upon the types of cable, cord and/or wire it is to accommodate. The bore may also be formed in various shapes and sizes or alternatively, a recess or slot may be provided to receive means for rotation of the cam. If a recess 42 is provided to receive the means for rotation of the cam, the cam is preferably provided with a locating spigot 44 to assist in the correct positioning of the cam 4 in the casing 2 (see figure 3b).

Alternatively, the casing may be provided with a locating spigot 54 for mating with a recess 56 provided in the base of the cam 4, as illustrated in Figure 5.

Referring to Figure 6 of the accompanying drawings, another embodiment of a connector according to the present invention is shown in which the cam 4 is provided with a plurality of spigots 64 and 66 extending from opposite surfaces thereof. One of the spigots 64 provides means for gripping the cam 4 to cause rotation thereof, for example, by means of a spanner, whilst the opposite spigot mates with a recess 68 or bore provided in the centre of the casing 2.

The casing and cam of the connector are preferably made of the same material such as a metal, metal alloy or plastics material. In the case of a connector for joining electrical cables and wires, the cam should be made of a conducting material, such as aluminium, copper, steel, gunmetal or bronze such that an electrical connection is formed between the two wires via the cam. If the connector is made of an alloy, it is preferable that the alloy contains at least 30% copper, more preferably at least 50% copper. A steel connector is ideally provided with an electroplated coating of zinc or nickel and chromium having a thickness of between 5 and 25 zm such as to conform with ISO standards.

A wide range of electric cables, cords or wires may be joined using the connector of the present invention. For example, the connectors may be used to join solid or stranded conductors of copper or aluminium which may be non-insulated, paper-insulated or polymeric-insulated. The solid conductors tend to be used in fixed installations and preferably are circular in cross section. The flexible conductors are preferably plain or metal-coated (eg. with a thin layer of tin, tin alloy or lead alloy) annealed copper and are used in, for example, overhead power lines.

It is to be appreciated that, although the invention has been described in detail with reference to electrical conductors, the connector may also be utilised to join strips of almost any types of material such as ropes and wires for fencing and alternative forms of conducting cables and wires, such as optical fibres. In such circumstances it would be necessary to join the cables by means of the earthing wire.

Referring to Figures 7a to 7g of the accompanying drawings, the procedure for connecting two, parallel cables using one embodiment of the connector of the present invention is illustrated. The parallel cables 8 are positioned in the casing 2 of the connector C such that they lie respectively against each of the inner, curved side walls 14 being covered in part by the flanges 18 of the casing (see Fig. 7a). The cam 4 is placed on a square section 38 of a key 20 with the spigot 40 of the key extending through the bore 34 of the cam (see Fig. 7b). The key is then used to place the cam inbetween the two cables 8, locating the free end of the spigot 40 in the hole 22 of the casing 2 (see Figs. 7c and 7d). The bar of the T-section 60 of the key is then turned in a clockwise direction to rotate the cam such that it is secured between the two cables, thereby forming a connection therebetween (see Figs. 7e and 7f). The key 20 is then removed from the connector 1, as shown in Fig. 7g leaving the cam sandwiched between the cables. Any tension that is put on the cables, for example during adverse weather conditions, would tend to tighten the cam action due to the self-locking mechanism of the cam. The cam may be removed to release the cables by carrying out the aforementioned process in reverse order and the connector may then be reused as required.

It is to be appreciated that the cam may also be provided with means to lock the connector, if required. For example, a ratchet mechanism may be used in which the sides of the cam are provided with teeth to grip the cables, thereby preventing movement of the cam in either direction once it has been rotated to the required degree.

Figures 1 to 5 show the connector being used to join parallel cables, such as electricity cables. However, the connector may connect different types of cables as illustrated in Figures 8 and 9 of the accompanying drawings. In Figure 8 the connection of a service or branch cable 9 to a main cable 8 is achieved using a connector of the present invention. The size and shape of the casing and cam would have to be adapted accordingly such that rotation of the cam would force the service branch against the walls of the casing. Figure 9 shows the connector of the present invention joining terminal cables.

The connector of the present invention provides a cheap and convenient means of joining lengths of wire, cord, cable and the like including electrical cables and optical fibres. The casing of the connector may be produced as an extruded parallel section, requiring only a simple cut-off operation to produce the component part with, optionally one or more holes being drilled or pierced therethrough. Similarly, the cam may be simply and cheaply manufactured in a variety of shapes and sizes. The connector also allows the installation engineer to fix the connector rapidly and securely thereby reducing installation time. Furthermore, such installation does not require the use of expensive and heavy tooling, such as crimping, percussion or hydraulic tools. Thus, the connector is particularly appropriate for the speedy repair of power lines down as a result of adverse weather conditions. The connector may also be adapted to be secured to most types of building or structure or may be independent thereof. The connector is releasable and may be reused, thereby reducing the amount of resources utilised in producing the connectors and the total cost spent on the installation of power lines and the like.

Claims

1. A connector for joining lengths of wire and the like comprising a casing for receiving the wires in a spaced side by side arrangement and a cam for placing between the wires, whereby rotation of the cam in a plane through the wires exerts a force on each wire to secure same against opposing walls of the casing.

2. A connector as claimed in claim 1, wherein the casing comprises a base having side walls at either end thereof.

3. A connector as claimed in claim 2, wherein the side walls are arcuate.

4. A connector as claimed in claim 2 or 3, wherein the casing is generally Cshaped in cross section.

5. A connector as claimed in claim 2, 3 or 4 wherein the walls of the casing are provided with inwardly extending flanges.

6. A connector as claimed in claim 2, wherein the casing is provided with a roof to form an oval shape in cross-section.

7. A connector as claimed in claim 6, wherein the base or roof of the casing is provided with a hole therethrough.

8. A connector as claimed in any one of the preceding claims wherein the casing is provided with at least one bolt hole.

9. A connector as claimed in claim 8, wherein the bolt hole is provided in the base and/or roof of the casing.

10. A connector as claimed in any one of the preceding claims, wherein the casing is provided with a bore, slot or recess therein.

11. A connector as claimed in claim 10, wherein the bore, slot or recess is through or in the centre of the casing.

12. A connector as claimed in any one of claims 1 to 9 wherein the casing is provided with a locating spigot extending from the base thereof.

13. A connector as claimed in claim 12, wherein the spigot extends from the centre of the base.

14. A connector as claimed in any one of the preceding claims, wherein the casing and the cam are made of the same material.

15. A connector as claimed in any one of the preceding claims, wherein the cam generally hexagonal in shape.

16. A connector as claimed in claim 15, wherein the cam is in the shape of an elongated hexagon.

17. A connector as claimed in any one of claims 1 to 14, wherein the cam is in the shape of an oval.

18. A connector as claimed in any one of the preceding claims, wherein the cam has concave sides.

19. A connector as claimed in any one of the preceding claims wherein the cam provides a self-locking mechanism.

20. A connector as claimed in claim 19 wherein the cam is provided with a ratchet mechanism to prevent further movement of the cam.

21. A connector as claimed in claim 20, wherein the ratchet mechanism is provided by means of teeth on the sides of the cam.

22. A connector as claimed in any one of the preceding claims, wherein the cam is provided with a bore or slot therethrough.

23. A connector as claimed in any one of claims 1 to 21, wherein a surface of the cam is provided with a recess therein.

24. A connector as claimed in claim 23, wherein the cam is provided with a locating spigot protruding from the surface opposite the recess.

25. A connector as claimed in claim 22, 23 or 24 wherein the bore or recess is square in cross section.

26. A connector as claimed in any one of claims 21 to 25, wherein the bore, slot or recess is positioned in the centre of the cam.

27. A connector as claimed in any one of claims 1 to 21 wherein the cam is provided with a spigot extending form both surfaces thereof.

28. A connector as claimed in claim 27 wherein the spigots extend from the centre of the cam.

29. A connector as claimed in any one of the preceding claims, wherein the cam is made of an electrically conducting material.

30. A connector as claimed in claim 29, wherein the cam is made of aluminium.

31. A connector as claimed in claim 29, wherein the cam is made of copper.

32. A connector as claimed in claim 29, wherein the cam is made of an alloy.

33. A connector as claimed in claim 32, wherein the alloy contains at least 30% copper.

34. A connector as claimed in claim 33, wherein the alloy contains at least 50% copper.

35. A connector as claimed in claim 32, wherein the alloy is steel.

36. A connector as claimed in claim 35, wherein the steel cam is coated with zinc.

37. A connector as claimed in claim 36, wherein the zinc coating is at least 5 ym in thickness.

38. A connector as claimed in claim 35, wherein the steel cam is coated with nickel and chromium.

39. A connector as claimed in claim 38, wherein the nickel and chromium coating is at least 20ym in thickness.

40. A connector as claimed in any one of the preceding claims, wherein the means for rotation of the cam is a T-shaped lever.

41. A connector as claimed in any one of claims 1 to 39, wherein the cam is rotated by means of a screw mechanism.

42. A connector as claimed in any one of claims 1 to 39, wherein the means for rotation of the cam is a key.

43. A connector as claimed in claim 42, wherein the key comprises a spigot, a square block section and a T-shaped section.

44. A connector as claimed in any one of the preceding claims, wherein the wires are conducting wires.

45. A connector as claimed in claim 44, wherein the conducting wires are in the form of electric cables, wires, cords or the like.

46. A connector as claimed in any one of claims 1 to 44 wherein the conductors are in the form of optical fibres.

47. A connector substantially as hereinbefore described and with reference to Figures 1 to 3a, 3b, 4, 5, 6, 7, 8 and 9 of the accompanying drawings.