Line protecting apparatus

Abstract

A link (10) of an articulated chain has end walls (12) which define the ends of the link and two cross bodies (14) which act as the top and bottom walls of the link in the operative, in use, orientation. Each end wall (12) defines a first engagement portion in the form of a recess (16) at the operative top and / or bottom of the end wall (12). The opposed ends of at least one cross body (14) define second engagement portions in the form of a trapezoidal projections (18) which are complementary to the first engagement recesses and snap fit into the recesses (16), in use. The projections each define a leading edge and a trailing end. Each projection and recess is shaped such that inserting the projections into the recess requires insertion and rotation of the projection to flex / deform the body defining the recess and cause a snap fit of the projection in the recess. In one version, the link is assemble from two identical end walls and two identical cross bodies.

Description

Line protecting apparatusCross Reference to Related ApplicationsThis application claims priority to Australian provisional application 2024903622 filed on 6 November 2024 and entitled “Line Protecting Apparatus”, the entire contents of which are hereby incorporated by reference.Technical Field

[0001] The present disclosure relates generally to an apparatus for protecting electric cables, water lines, fibre optic cables, hoses, fluid lines, and the like (hereinafter referred to as lines or service lines, particularly, but not exclusively, in underground workings.Background

[0002] During mining operations it is necessary to protect a variety of electrical cables, water hoses and other service lines from damage. Particular areas of operation include longwall coal mining, where line protecting apparatus (also known as cable handlers) is required, and in the area of mine tunnelling and strata drilling. In longwall coal mining, a coal cutter traverses back and forth across a coal face depositing coal cut from the coal face into a conveyor disposed behind the coal cutter. In order to operate, the coal cutter requires a supply of water and electricity, which are provided by service lines. The service lines are located in a trough which is typically disposed on the opposite side of the conveyor from the coal cutter and the lines travel up and down the trough trailing the coal cutter as it traverses the coal face. In tunnelling and strata drilling, in which a roadway cutter or drill rig uses on board hydraulically powered drill rigs, the services are once again totally enclosed but hang freely. In order to operate, the road header or drill rig requires a supply of high pressure hydraulic oil, which is provided by service lines. The service lines are suspended in a suitably sized handler connected between a power pack and a drill rig motor. It should be notedhowever, that whilst the type of apparatus envisaged by the present invention is particularly suitable for use in handling and protecting service lines for longwall coal mining, other applications of the apparatus are possible.

[0003] In order to protect such service lines, it is known to enclose, or at least partially enclose them in a protective articulated cable handler formed from a plurality of interconnected links which protects the service lines within the trough. There are a number of known cable handlers which perform that function and the various different existing designs have their own advantages and disadvantages compared to each other.

[0004] US 4988838 discloses one such cable handler formed from a plurality of interconnected links. Each link has a central web forming a common base for a pair of laterally open channels on respective sides of the central web. For at least some of the links, each channel is formed with an inwardly extending nib so that the entrance to the channel is narrower than the width of the channel. Each link is formed from a plastics material, typically nylon, so that the channel sides are resiliently flexible and a service line can be inserted into a respective one of the channels by deflecting walls of the channel and the nibs apart. After a service line is passed through the channel entrance, the channel sides return back to regain their original position and thus prevent the line from inadvertently moving out of the channel. The links are joined by linking the central web of one link to adjacent links hence such cable handlers are referred to as "centre pull" cable handlers. Centre pull cable handlers also preferred because the water hose is kept separate from the electric cable for safety and reliability reasons.While the cable handler is relatively simple to use, this design has the disadvantage that the end of the channels are not fully closed so protection of the service lines is more limited and the cable handler has to be removed from the trough to insert the service lines into the channels.

[0005] PCT / GB95 / 00384 discloses a development of the apparatus shown in US 4988838 in which the web is located to one side of the link instead of being centrally located, and the channel is approximately twice the depth of the centre pull design.This type of cable handler is referred to as a "side pull" cable handler, as the links are articulated via the side web and are pulled along one side only.

[0006] One problem which is common to the cable handlers of both US 4988838 and PCT / GB95 / 00384 results from the presence of stones, flints and the like in the trough along which the cable handler runs. These flints and stones are often narrower than the channel entrance and they can enter the channel and may puncture the water hose or electric cable, thus interrupting the supply of power or water to the coal cutter and disrupting production. Further, the type of heavy duty cables used in underground mining are expensive, particularly the electric cables. The cost of replacing any damaged cables, is high, such that in some environments, mining operators will not use cable handlers of the type described in US 4988838 because of the potential for costly damage to the service lines.

[0007] To avoid this problem, twin pull cable handlers have been developed and are currently used at many longwall operations, particularly in the USA, Australia and China. In a twin pull cable handler, each link defines a generally rectangular shaped box in which the electric cable and water line are located. The water hose can be kept separate from the electric cable as with the centre pull design. A removable plate or plates are bolted or otherwise fixed to the tops of the side walls of the rectangle, thereby locking the cables in the U shaped link. The base, side walls, and plate are all solid providing all round protection for the electric cable and water line. The links may be linked / pulled from either or both sides, and are typically pulled from both sides, hence the name "twin pull". However, whilst such a twin pull design provides a high degree of protection for cables, it will be appreciated that it is an extremely lengthy, tedious and time consuming process to install a pair of lines in a twin pull cable handler compared to a centre pull cable handler such as in US 4988838 or a side pull cable handler, because of the need to attach a plate to each link in turn. For a typical longwall mine which might require a cable handler which is many metres long, this may take many hours, even days, and will result in loss of operating time. There is also the risk of the bolts, clips or the like securing the plates to the channels, becoming loose and separating from the channel. It will also be appreciated that, because the links haveto be articulated to allow the cable to fold back upon itself, as the coal cutter traverses up and down the coal face, however the cable handler is designed, it is impossible to totally enclose the cables in a cable handler which is made of articulated rigid protective elements, as gaps are required between links to allow articulation.

[0008] US 6789383 is one example of a twin pull cable handler. This design has a number of drawbacks. First the water hose and electrical cable are not kept separate. More importantly while the cable handler is a top loader and allows access to the links through the top of the cable handler, the connection mechanism is complex and requires a pin to be turned through an angle to release and or secure the top of the cable handler to the body of each link. A specialist tool is required to turn the pin. Thus the cable handler is relatively complex to manufacture and assemble. Also moving parts such as the pin are susceptible to damage and can become frozen or stuck due to the degree of dust, dirt and the like in the trough which can set like concrete.

[0009] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each of the appended claims.Summary

[0010] According to some disclosed aspects, a link of a chain link for protecting cables, including electric and fibre optic cable, hoses, service lines and the like, the link comprising: two opposed end walls, each end wall having a pair of laterally spaced coupling portions, each coupling portion defining an aperture for receiving a fastener to pivotally couple the side wall to an adjacent side wall of another link, each opposed end wall defining a first engagement portion arranged at the top or bottom of the side wall, in use;a pair of cross bodies extending between the end walls, at least one cross body being separable from the link and having opposed ends and a pair of second engagement portions arranged at the ends, the second engagement portions being arranged to engage with the first engagement portions so as to from a link having an operative top and a bottom and side walls in use, defining one or more conduits for a hose or cable or the like within the link; and wherein the first or second engagement portions define a pair of trapezoidal projections, and the other of the first or second engagement portions define a pair of trapezoidal shaped recesses, whereby the recesses are arranged to receive the projections being inserted from the operative top or bottom of the link, the projections each defining a leading edge and a trailing end; and wherein each projection and recess is shaped such that inserting the projections into the recesses causes resilient deformation of the body or wall defining the recess and wherein the recess is typically shaped such that inserting the leading edges of the projection into the recess requires insertion and rotation of the projection to flex / deform the body defining the recess and cause a snap fit of the projection in the recess.

[0011] In one preferred aspect, particular suited for use with longwall mining apparatus, there is provided a link of a chain link for protecting cables, including electric and fibre optic cable, hoses, service lines and the like, the link comprising: two opposed end walls, each end wall having a pair of laterally spaced coupling portions, each coupling portion defining an aperture for receiving a fastener to pivotally couple the side wall to an adjacent side wall of another link, each opposed end wall defining a pair of first engagement portions, one arranged at the top of the side wall, in use, and the other at the bottom of the side wall, in use; and a pair of cross bodies extending between the end walls, each cross body having opposed ends and a pair of second engagement portions arranged at the ends, the second engagement portions being arranged to engage with the first engagementportions so as to from a link having an operative top and a bottom and side walls in use, defining one or more conduits for a hose or cable or the like within the link; and wherein the first or second engagement portions define a pair of trapezoidal projections, and the other of the first or second engagement portions define a pair of trapezoidal shaped recesses, whereby the recesses are arranged to receive the projections being inserted from the operative top or bottom of the link, the projections each defining a leading edge and a trailing end; and wherein each projection and recess is shaped such that inserting the projections into the recesses causes resilient deformation of the body or wall defining the recess and wherein the recess is typically shaped such that inserting the leading edges of the projection into the recess requires insertion and rotation of the projection to flex / deform the body defining the recess and cause a snap fit of the projection in the recess.

[0012] Advantageously, being able to attach and / or remove a cross body from the operative top of the link allows assembly of the module from above while the module is arranged within the trough. Removal of the cross body also provides access to services from above without lifting the module from the trough. This enhances the speed of assembling and / or removal of the module and minimises downtime when replacing the assembly or repairing the service lines. In longwall mining wear contact occurs on the link on both sides and is bi-directional and requires removable cross bodies on both top and bottom of the links.

[0013] However, in some applications, access to the service lines from one side only is required. These applications include such as roadway drilling / bolting machines used underground which also have chain links to protect hydraulic hoses. In that case only one cross body is removable from the link, and the side walls are permanently connected by an integrally moulded cross body, so that the link comprises a generally U-shaped portion and a single removable cross body.

[0014] The resilient deformation is repetitive and consistent and the insertion and removal of the projections into the recesses can be repeated multiple times.

[0015] The engagement of the cross body to the end walls is a simple snap fit and requires no special tools or additional components so can be quick and reliable. The engagement provides the locking - no additional manipulation of components is envisaged. While no special tools are required it is anticipated that some percussive impact force may be required to engage the components together and a standard off the shelf mallet or the like may be used for that purpose.

[0016] The simplicity of the design and engagement is significant as the link operates in a channel which typically contains debris from mining, coal dust, dirt and other powdered material which tends to get into parts of links and can inhibit movement of components and in some cases can solidify and set like concrete. Links that require nuts and bolts to connect or relying on moving components are not always reliable and easy to change over.

[0017] Typically, the leading edge is generally wedge shaped and an operative upper surface of the leading edge is gently curved and concave. The depth of the projection may diminish from the trailing edge of the projection to the leading edge.

[0018] It is preferred that the trailing end of the projection defines a bulbous projection

[0019] The bulbous projection is typically disposed to one side of the trailing end of the projection.

[0020] In one embodiment, the first engagement portions are the recesses, and the second engagement portions are the trapezoidal projections.

[0021] Typically, the recesses are shaped and configured to receive the trapezoidal projections in a close fit with minimal clearance. The vertical engagement surfaces are tapered to enhance retention and to provide stability to the assembled link.

[0022] In a preferred aspect, the laterally spaced coupling portions of each end wall include a metal insert, preferably steel, and a body portion of the end wall is moulded over the link in a plastics material, most preferably nylon.

[0023] In some embodiments the two end walls are identical and possess mirror symmetry about a central axis.

[0024] In some embodiments the two end cross bodies are identical. In this way the entire link can be assembled from two different component parts, minimising inventory.

[0025] In one embodiment, the metal insert comprises a single metal plate having a thickness of 4.5mm to 5.5mm, preferably about 5mm being cranked and comprising two parallel end portions defining apertures connected by an angled link.

[0026] The invention also envisages an articulated cable handler for protecting cables, service lines, or the like, comprising a plurality of interconnected links according to any of the above listed aspects and preferred embodiments.

[0027] Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

[0028] It will be appreciated embodiments may comprise steps, features and / or integers disclosed herein or indicated in the specification of this application individually or collectively, and any and all combinations of two or more of said steps or features.Brief Description of Drawings

[0029] Specific embodiments of the invention will now be described by way of example only with reference to the accompany drawings in which:Figure 1 is an isometric view of a link of a first embodiment of the present invention.Figure la shows an exploded view of the link of Figure 1 with a top cross body component removed;Figure 2 is a front view of the link of Figure 1;Figure 3 is an isometric view of the top cross body;Figure 4 is a side view of the top cross body shown in Figure 3;Figure 5 is a top plan view of the top cross body shown in Figure 3;Figure 6 is an isometric view of an end wall of the link;Figure 7 is a side view of the end wall shown in Figure 6;Figure 8 shows the opposite side of the end wall to that shown in Figure 7.Figure 9 shows a front view of an alternative single layer insert for the end wall;Figure 10 shows a side view of the single layer insert of Figure 9;Figure 11 shows a rear view of the single layer insert of Figure 9;Figure 12 shows a variant of the link in which only one cross body is removable; andFigure 13 shows the variant of Figure 12 with the parts separated.Description of Embodiments

[0030] In the drawings, reference numeral 10 generally designates a first embodiment of a link which forms one link of an articulated chain. The link is assembled from four components. The four components comprise two identical end walls 12 which define the ends of the link and two identical cross bodies 14 which act as the top and bottom walls of the link in the operative, in use, orientation. Figures 3 to 5 show views of the cross body component 14 and Figures 6 to 8 show views of the end wall component 12.

[0031] Figure 2 shows the link with top cross body 14 removed from the side walls, leaving the bottom cross body 14 connecting the two end walls 12. Complementary engagement means are provided for connection of the pair of end walls 12 to the pair of cross bodies 14. In particular, with reference to Figure 2 and Figures 6 to 8, each end wall defines a first engagement portion in the form of a recess 16 at the operative top and bottom (refer to Figure 6) of the end wall 12. The opposed ends of the cross body 14 define second engagement portions in the form of a trapezoidal projections 18 which are complementary to the first engagement portions / recesses and snap fit into the recesses 16, in use.

[0032] The end walls 12 are best seen in Figures 6 to 8. Each end wall 12 is formed from a moulded plastics material typically nylon, typically low to medium viscosity nylon, although other materials could be suitable. Each end wall incorporates a steel insert 20 (only part of which is visible in the drawings, due to the nylon over-moulding) to provide additional towing strength and the linkage means.

[0033] The steel insert 20 comprises two parallel cranked linkage elements. Each linkage element is about 3.5mm thick. (Figures 9 to 11 show an alternative single thickness insert, which is described in more detail below). At one (leading) end 22 the insert defines a through aperture 24 and at the other (trailing) end 25 defines two parallel arms 26 which define two coaxial apertures 28. The relatively narrower leading end can be inserted between the arms 26 of an adjacent insert / link and theinserts / links may be linked together with a bolt or other suitable connector passing though the apertures 24 and 28.

[0034] With reference to Figures 7 and 8 in particular, the side walls 12 are symmetrical being a mirror image about a longitudinal axis passing through the centres of the apertures 24, 28 and the arrow 30 which is moulded into the side of the outer face of the side wall which faces the outside of the link. The arrow 30 points in the direction of movement of the articulated cable handler through the trough in use, to ensure the chain is correctly assembled. As seen in Figures 7 and 8, the side walls are approximately hexagonal, but rounded around the apertures 24 and 28. The operative top and bottom define the recesses 16. The upper and lower edges of the leading end 22 of the side walls define a series of four steps 32, which act as cleaning teeth and help to clean out any coal / stone / silica build up between the links when the chain is articulating.

[0035] The recesses 16 have a shape which is complementary to the shape of the trapezoidal projections 18. The forward end 34 of the recess, in the direction of travel of the link in use, is generally triangular, although curved, and is undercut to receive the leading edge of the trapezoidal projection. The rear or trailing end 36 of the recess has a convex curved portion 38 at its top and a generally vertical wall with a tapering bulbous projection 42 (also seen in Figure la) on one side.

[0036] The cross body 14 is best seen in Figures 2 to 5. As discussed above, the opposed ends of the cross body define trapezoidal projections. The top of the cross body is generally planar but defines two recessed arrows 44 which point in the direction of movement of the link, in operation. The underside of each link as is best seen in Figure 2, defines two arcuate recesses, one smaller 46 and one larger recess 48 disposed on opposite side of a central pillar, in the top of which is a semicircular recess 50.

[0037] As is best seen in Figure 2 when assembled the cross bodies define two larger apertures 54 and 56 comprising the smaller recess of the lower cross body and thelarger recess of the upper cross body, and the larger recess of the lower cross body and the smaller recess of the upper cross body. In use, one of the two larger recesses will typically receive and protect a water line and the other an electrical power line. In the centre of the link there is a smaller aperture 58 formed by the two semicircular recesses 50, which can receive fibre optic cable or the like.

[0038] The trapezoidal projections 18 are best seen in Figure 4. The leading edge 60 of the projection is generally wedge shaped and the operative upper surface 62 of the leading edge is gently curved and concave, similar to a duck’s beak. The depth of projection increases gradually and from the leading edge of the projection to the rear or trailing edge, so that the underside 64 of the projection is planar and angled relative at around 10 to 15° relative to the top surface of the cross body.

[0039] The sides 66 of the projections are curved and convex. As is best seen with reference to Figure 4, the trailing edge 68 of the projection is curved and slightly convex and as shown in Figure 5, the trailing edge 68 of the projection is angled rearwards and defines a bulbous portion 70 at the outer edge. The trailing edge is configured to mate with the rear / trailing edge of the recess. Both the front side and rear side walls of the projections are tapered. The tapering enhances the retention of the projections in the recess and improve the stability of the assembled link.

[0040] With reference to Figure 2, to attach the cross body 14 to the two end walls 12 the leading edges 60 of each projection are inserted into the recesses 16 and at the same time are rotated / pivoted towards the end walls (in a clockwise direction). This causes resilient deformation of the body or walls of the end wall defining the recess 16 and allows a snap fit of the projection 18 in the recess 16. As discussed above, in some cases force may be applied to achieve the necessary fit, including the use of mallets or similar. The bulbous portions on the trailing edge of the projection and recess not only assist in the deformation of the recess to receive the projections, and also inhibit lateral movement of the project! ons / cross body.

[0041] In use, the links can be assembled in situ without the need for specialist tools. Each link is made up of two of each of the two components 12, 14, which minimises manufacturing and inventory costs. A mallet or the like may be required to connect the cross bodies to the end walls, but no specialist tools are needed. As discussed above the links are connected together by inserting the relatively narrower leading ends of the side walls of the link inserted between the arms of an adjacent insert / link and the inserts / links are linked together with a bolt or other suitable connector passing though the apertures 24 and 28.

[0042] Figures 9 to 11 show an alternative design of steel insert 100 which is single thickness rather than double. The steel insert is generally rectangular in plan view but has arcuate curved ends, 102, 104. A circular aperture 106, 108 is defined in the centre of each end, 102, 104. The smaller aperture 108 is threaded. The larger aperture 106 is unthreaded. As is best seen in Figure 10 the insert is cranked with the two ends parallel and connected by an angled link 110 such that the ends are offset by the 5mm thickness of the insert. The thicker insert provides an increased tensile strength about 40% better than the double insert 20, as well as using less material and reducing complexity. In use, to connect the inserts a threaded bolt passes through the larger unthreaded aperture 106 in one end wall / link and is threaded into the smaller threaded aperture of an adjacent end wall / link

[0043] The link offers a number of advantages over existing cable handlers. First, it is possible to attach and / or remove a cross body 14 from a link from the operative top of the link (“top loading”). This allows assembly of the module from above while the module is arranged in the trough / channel. This can enhance the speed of assembly of the cable handler as well as minimising downtime when replacing, or repairing the assembly.

[0044] The engagement portions eliminate any requirement for a pin or other fastener to retain the cross bodies and end walls together allowing tool free assembly of the link.

[0045] Finally, the engagement mechanism is robust, and as the link does not rely on pins, moveable or otherwise, or fasteners, the link will survive prolonged use in an underground mine environment and in particular while being dragged along a trough, which typically contains high levels of dust, dirt, powdered coal, flints and other powdered materials.

[0046] In some applications, access to the service lines from one side only is required. These applications include roadway drilling / bolting machines used underground which also have chain links to protect hydraulic hoses. In that case only one cross body is removable from the link, and the side walls are permanently connected by an integrally moulded cross body, so that the link comprises a generally U shaped portion and a single removable cross body.

[0047] Figures 12 and 13 illustrate such a variant 10A. The removable cross body 14 is identical to the cross body of the first embodiment shown in Figures 1 to 8 and the recessed in the top of the side walls 112 of the link and the trapezoidal projections 18 are also the same, as those of the first embodiment. In this case however the side walls 112 and lower cross body 114 are integrally moulded as a single generally U-shaped component 120. The variant may or may not include formations for supporting and receiving a service line, hose or similar.

[0048] It will be appreciated by persons skilled in the art that numerous variations and / or modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

CLAIMS:

1. A link of a chain link for protecting cables, including electric and fibre optic cable, hoses, service lines and the like, the link comprising: two opposed end walls, each end wall having a pair of laterally spaced coupling portions, each coupling portion defining an aperture for receiving a fastener to pivotally couple the side wall to an adjacent side wall of another link, each opposed end wall defining a first engagement portion arranged at the top or bottom of the side wall, in use; a pair of cross bodies extending between the end walls, at least one cross body being separable from the link and having opposed ends and a pair of second engagement portions arranged at the ends, the second engagement portions being arranged to engage with the first engagement portions so as to from a link having an operative top and a bottom and side walls in use, defining one or more conduits for a hose or cable or the like within the link; and wherein the first or second engagement portions define a pair of trapezoidal projections, and the other of the first or second engagement portions define a pair of trapezoidal shaped recesses, whereby the recesses are arranged to receive the projections being inserted from the operative top or bottom of the link, the projections each defining a leading edge and a trailing end; and wherein each projection and recess is shaped such that inserting the projections into the recesses causes resilient deformation of the body or wall defining the recess and wherein the recess is typically shaped such that inserting the leading edges of the projection into the recess requires insertion and rotation of the projection to flex / deform the body defining the recess and cause a snap fit of the projection in the recess.

2. A link as claimed in claim 1 wherein one cross body is integrally formed with the side walls, so as to define a generally U-shaped body to which one cross body can be attached and removed.

3. A link of a chain link for protecting cables, service lines and the like, the link comprising: two opposed end walls, each end wall having a pair of laterally spaced coupling portions, each coupling portion defining an aperture for receiving a fastener to pivotally couple the side wall to an adjacent side wall of another link, each opposed end wall defining a pair of first engagement portions, one arranged at the top of the side wall, in use, and the other at the bottom of the side wall, in use; and a pair of cross bodies extending between the end walls, each cross body having opposed ends and a pair of second engagement portions arranged at the ends, the second engagement portions being arranged to engage with the first engagement portions so as to form a link having an operative top and a bottom and side walls in use, defining one or more conduits for a service line such as a hose or cable, or the like within the link; and wherein the first or second engagement portions define a pair of trapezoidal projections, and the other of the first or second engagement portions define a pair of trapezoidal shaped recesses, whereby the recesses are arranged to receive the projections being inserted from the operative top or bottom of the link, the projections each defining a leading edge and a trailing end; and wherein each projection and recess is shaped such that inserting the projections into the recesses causes resilient deformation of the body or wall defining the recess and wherein the recess is preferably shaped such that inserting the leading edges of the projection into the recess requires insertion and rotation of the projection to flex / deform the body defining the recess and cause a snap fit of the projection in the recess.

4. A link of a chain link as claimed in any preceding claim wherein the leading edge is generally wedge shaped and an operative upper surface of the leading edge is gently curved and concave and wherein the depth of the projection diminishes from the trailing edge of the projection to the leading edge.

5. A link of a chain link as claimed in any preceding claim wherein the trailing end of the projection defines a first bulbous projection6. A link of a chain link as claimed in claim 5 wherein the first bulbous projection is disposed to one side of the trailing end of the projection and a second bulbous projection is disposed on one side of the recess with the first and second projections being laterally spaced in use so as to inhibit relative lateral movement of the projection within the recess.

7. A link of a chain link as claimed in any preceding claim wherein the first engagement portions are the recesses, and the second engagement portions are the trapezoidal projections.

8. A link of a chain link as claimed in claim 7 wherein the sides of the trapezoidal projections are tapered and the recesses, are shaped and configured to receive the trapezoidal projections in a close fit with minimal clearance.

9. A link of a chain link as claimed in any preceding claim wherein the laterally spaced coupling portions of each end wall include a metal insert, preferably steel, and a body portion of the end wall is moulded over the link in a plastics material, most preferably nylon.

10. A link of a chain link as claimed in claim 3 or in any one of claims 4 to 10 when dependent on claim 3 wherein the two end walls are identical and possess mirror symmetry about a central axis.

11. A link of a chain link as claimed in in claim 3 or in any one of claims 4 to 11 when dependent on claim 3 wherein the two end cross bodies are identical.

12. A link of a chain link as claimed in any in claim 3 or in any one of claims 4 to 11 when dependent on claim 3 wherein the link of each end wall comprises two substantially identical end walls and two substantially identical cross bodies.

13. A link of a chain link as claimed in claim 9 or any one of claims 10 to 12 when dependent on claim 9, wherein the metal insert comprises a single metal plate having a thickness of 4.5mm to 5.5mm, preferably about 5mm, being cranked and comprising two parallel end portions defining apertures connected by an angled link.

14. A link of a chain link as claimed in any preceding claim wherein the cross bodies include arcuate shaped recessed configured to receive and support service lines or the like.

15. An articulated cable handler for protecting cables, service lines, or the like, comprising a plurality of interconnected links as claimed in any one of claims 1 to 14.

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