GB2469521A - Cable with integral support structures - Google Patents

Abstract

A cable 20 comprises a conducting element 102, 104, 106 surrounded by an insulating sheath 11 that is with opposed, curved protrusions 14, along at least a part of its longitudinal length, for fixing the cable 20 to a structure (6, fig 3) e.g. a lamp. The protrusions 14 may be C-shaped with a groove 16. A variety of other shapes are disclosed (figs 4-13). Also described are a cable support fixture (140, fig 14), a cabling system, an extrusion die (150, fig 15), a method of installing the cable, and a method of manufacturing the cable.

Description

CABLES

DESCRIPTION

The present invention relates to cables, cable support fixtures, cable systems, the manufacture of cables, extrusion dies for manufacturing cables, and methods of installing cables. The present invention is particularly suited to, but not limited to, electrical cables, i.e. cables with one or more electrically conducting elements, e.g. for conveying power and/or data, and optical fibre cables, i.e. cables with one or more light conducting or light guiding elements, e.g. for conveying data.

Cables, for example mains power supply cables, lighting cables, telephone cables, computer network cables, and so on, are commonly used in domestic, commercial and industrial environments to supply power and/or data signals.

Known types of cable include electrical cable and fibre optic cable.

Cables comprise one or more conducting elements. For example, an ::..: electrical mains power supply cable for the UK will typically comprise three separate conducting elements extending longitudinally, i.e. axialiy, along the cable. One conducting element is for connection to the live mains power supply connection, one conducting element is for connection to the neutral mains power supply connection, and one conducting element is for connection to the earth *. connection. Each of the earth, live and neutral conducting elements may be a single electrically conducting wire such as copper, or may comprise multiple strands of a conducting wire such as copper, twisted together. Each conducting element is typically enclosed within a respective inner insulating sheath that also extends longitudinally along the axial direction of the cable and is often colour coded, e.g. brown for live, blue for neutral and green/yellow for earth. However, this is not always the case, for example often only the live and neutral conducting elements are enclosed within respective inner insulating sheaths.

The conducting elements (and any inner insulating sheaths) are enclosed in an insulating outer sheath which also extends longitudinally along the axial direction of the cable. The outer sheath provides electrical insulation, the main physical and strength form of the cable as a whole, and also provides protection against environmental conditions, e.g. damp, erosion and so on. A common material for the outer sheath is PVC. The outer sheath is typically of a resilient material. The outer sheath is typically coloured white, but this is not always the case. In some cases the different conducting elements (and any associated inner insulating sheaths) are separately located in the outer sheath. In other cases, the different conducting elements (and any associated inner insulating sheaths) are located or bundled together in an intermediate insulating sheath, which is then located in the outer sheath.

Typically the outer sheath is essentially of solid cross-section, with the conducting elements (with any associated inner or intermediate sheaths) embedded or integrated within the outer sheath material (thereby effectively *:". forming a void). In some cases the conducting elements (with any associated inner or intermediate sheaths) may be in full and close contact to the inner surface of the void(s) of the outer sheath material where they are located, or there may be a looser fitting.

In the case of optical cables, the conducting element comprises optical fibre that conducts, i.e. guides, light,including e.g. near infra-red wavelengths.

* The optical cable may comprise one or more layers of cladding around the optical *. fibre that play a role in the light guiding. Additionally, the optical fibre and any cladding are typically enclosed in an insulating outer sheath which extends longitudinally along the axial direction of the cable. The insulating outer sheath corresponds to the insulating outer sheath of electrical cables as described above.

Known cables and methods of manufacturing such cables are described, for example in Electric Cables Handbook by B.F. Moore, BICC Cables Ltd, published 1997 by Blackwell Publishing. Methods of fabricating cables by extrusion are known from WO 2006/114118, WO 2006/056218 and EP-A-0 535 835. Typical insulation materials are detailed in WO 2000/017889. A known extrusion die is disclosed in US 4,093,914.

An example of a typical application where a power supply cable is used is in lighting systems.

Figure 1 is a schematic illustration of one type of overhead light fitting 1 shown electrically connected to the mains power supply by a conventional electrical cable 8. The light fitting 1 comprises a ceiling rose 2 for attaching the light fitting 1 to the ceiling. The light fitting 1 further comprises a light unit 4 suspended from the ceiling rose 2 by a support structure comprising rods 6 (which may also be termed struts). The electrical cable 8 is fd through the ceiling rose 2 to the light unit 4 to allow electrical connection of the light unit 4 to the mains power supply. Typically, the electrical cable 8 is, as shown, wound around one of the rods 6 or is left hanging freely. As can be seen from Figure 1, * 20 in the known wiring method the cable is not easily supported by the light fitting.

One disadvantage of the known cable and wiring method is that the cable *** U is difficult to install and maintain. For example it is difficult to wire a cable to the electrical connecting block in the ceiling if the cable is hanging loose as the cable **** will move around whilst the installer attempts to support the fitting and manipulate the tools to attach the wires to the connector. Furthermore, once installed, a loose hanging cable is difficult to keep clean as wiping an unsupported cable risks inadvertently disconnecting the cable at either end.

Another disadvantage is that the cable is in an undetermined location. This can lead to problems such as inconsistent installation between different light fittings. Also, since the cable is free hanging, other problems arise, such as the cable can become caught up on other structures and fittings, and is prone and exposed to accidental damage, e.g. when the light fitting is being cleaned or maintained.

Another disadvantage is that the unsupported wire is aesthetically unpleasing. In the above mentioned application, light fittings are often expensive designer items chosen to give a particular aesthetic effect.

Known methods of attaching a cable to an item include using special clips or cable ties. However, problems remain when clips are used. For example, if a relatively small number of clips are used, then the cable remains unsupported or guided for relatively large stretches. This can leave the disadvantages of unfixed cable significantly unresolved. For example, the cable will still be free hanging in an undetermined location between the clips, and e.g. the catching problem can therefore remain. On the other hand, if a relatively large number of clips are used, then this makes installation time-consuming and generally inefficient.

The present inventor has realised it would be desirable to alleviate the * * S problems derived from the cabling being free-hanging and of indeterminate *..S * S location. The present inventor has further realised it would be desirable to overcome or avoid the inefficiencies that would arise from merely using a very *** * large number of clips.

In a first aspect, the present invention provides a cable, comprising: a *. conducting element surrounded by an insulating sheath, wherein the insulating *. sheath is shaped, along at least a part of its longitudinal length, for fixing the cable to a structure.

In a further aspect, the present invention provides an electrical or fibre optic cable with an outer sheath whose cross-sectional profile is adapted for attaching lengthwise to on or more support structures.

In a further aspect, the present invention provides an electrical or fibre optic cable with an outer sheath shaped in cross-section to provide one or more protrusions adapted to push fit or clip to a support structure.

In a further aspect, the present invention provides a cable whose cross-sectional shape provides at least one protrusion or other form for attaching the cable.

In a further aspect, the present invention provides a cable whose cross-sectional shape provides at least one protrusion or other form for attaching the cable longitudinally along its axial direction.

In a further aspect, the present invention provides a cable support fixture comprising a support structure extending along a support member, wherein the support structure is shaped for having a cable according to any of the above aspects fixed to the support structure by the fixing means.

In a further aspect, the present invention provides a cabling system comprising a support fixture according to the above aspect and one or more cables according to any of the above aspects fixed to support structures of the support fixture. * * *

In a further aspect, the present invention provides an extrusion die for use *.* in manufacturing a cable comprising an insulating sheath around a conducting : element; the extrusion die comprising an opening for feeding insulating material *** * through to form the insulating sheath around the conducting element; the opening being shaped so as to provide a shape to the insulating sheath that provides a means for fixing the cable to a structure.

*. In a further aspect, the present invention provides a method of installing a cable, the method comprising fixing the cable to a structure using a fixing means provided by the shape of the insulating sheath of the cable.

In a further aspect, the present invention provides a method of manufacturing a cable, the method comprising providing an insulating sheath around a conducting element, wherein the insulating sheath is provided so as to be shaped, along at least a part of its longitudinal length, for fixing the cable to a structure.

In each of the above aspects, the insulating sheath may comprise a protrusion part of the cross-sectional shape of the insulating sheath.

In each of the above aspects, the protrusion part may be substantially C-shaped with a longitudinally extending groove.

In each of the above aspects, the longitudinally extending groove may have an inner part and an opening, the opening being smaller than the inner part.

In each of the above aspects, the protrusion part may contain a groove for enclosing the structure.

In each of the above aspects, the insulating sheath may comprise a slot adjacent the groove, the slot being for closing together once a structure is in the groove so that the insulating sheath surrounds the structure.

In each of the above aspects, a channel may be provided between the protrusion part of the insulating sheath and a part of the insulating sheath enclosing the conducting element, the channel being for facilitating separation of the protrusion part of the insulating sheath from the conducting element part of : the insulating sheath. *.**

In each of the above aspects, the protrusion part may comprise an extension and a flange. S...

* In each of the above aspects, the insulating sheath may be shaped, along at least a part of its longitudinal length, so as to provide plural means for fixing the cable to structures.

*:*. In each of the above aspects, the cable may comprise a plurality of conducting elements all provided in a single conducting core structure.

In each of the above aspects, the cable may comprise a plurality of conducting elements provided adjacent each other.

In each of the above aspects, the cable may comprise a plurality of conducting elements located in separate parts of the cross-sectional shape of the insulating sheath, wherein at least one of the conducting elements is located in a part of the shape of the insulating sheath that provides fixing.

In each of the above aspects, the insulating sheath may be shaped along its entire length, or along substantially its entire length, for fixing the cable to a structure.

In each of the above aspects, the structure may be another cable.

In each of the above aspects, the conducting element may be an electrical conductor for conducting one of the following: power; data; power and/or data.

In each of the above aspects, the conducting element may be of fibre optics.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic illustration of one type of overhead light fitting shown electrically connected to the mains power supply by a conventional electrical cable; Figure 2 is a schematic illustration of a cable; as..

Figure 3 is a schematic illustration of the cable of Figure 2 applied to the light fitting shown in Figure 1; *S..

***** Figures 4-13 are schematic cross-sectional illustration of further cables; *., Figure 14 is a schematic illustration of a cable support fixture with a plurality of the cables of Figure 2 attached thereto; and Figure 15 is a schematic illustration of an extrusion die which may be used in the manufacture of the cable of Figure 2.

Figure 2 is a schematic illustration of a cable 20 in accordance with a first embodiment of the present invention. The figure shows a length of the cable 20 extending longitudinally in its axial direction X. In this embodiment the cable 20 is an electrical cable, more particularly a mains power supply lead, comprising respective earth, live and neutral conducting elements 102, 104, 106 each extending longitudinally along the axial direction of the cable (shown as direction X). Each of the earth, live and neutral conducting elements 102, 104, 106 comprises multiple strands of a conducting wire, such as copper, twisted together. Each conducting element 102, 104, 106 is enclosed within a respective inner insulating sheath 202, 204, 206 that also extends longitudinally along the axial direction X. The respective insulating sheaths 202, 204, 206 are differently coloured to enable an electrician to * ..* * * * distinguish between them. The three conducting elements 102, 104, 106 and their respective inner insulating sheaths 202, 204, 206 are enclosed together within an intermediate insulating sheath 208 that also extends longitudinally S...

along the axial direction X. The intermediate insulating sheath 208, the three conducting elements 102, 104, 106 and their respective inner insulating sheaths 202, 204, 206 together form a conducting core structure 10 of the cable 20, the *** conducting core structure 10 extending longitudinally along the axial direction X. The conducting core structure 10 is surrounded by a solid but flexible insulating outer sheath 11 which also extends longitudinally along the axial direction X enclosing the conducting structure 10. The outer sheath 11 is essentially of solid cross-section, as indicated by the large shading in Figure 2, with the conducting core structure 10 embedded or integrated within the outer sheath material (thereby effectively forming a void). In practise the conducting core structure 10 may be in full and close contact to the inner surface of the void of the outer sheath material, or there may be a looser fitting. The outer sheath 11 in this embodiment comprises PVC. The outer sheath 11 could, however, comprise any insulating and resilient material conventionally used in existing cables, for example a thermoplastic polymer. For electrical applications, suitable materials should be capable of forming a water blocking layer and should exhibit electrical insulation properties as required by regulations set out by the relevant national regulatory body. For example, in the UK, wiring installations are regulated by the lET Requirements for Electrical Installations: lET Wiring Regulations, BS 7671: 2001.

The outer sheath 11 is this embodiment is formed by extrusion. However, the outer sheath 11 could be formed by any other appropriate technique eg.

moulding.

As shown in Figure 2, the outer sheath 11 of the cable 20 has an approximately "C -shaped" cross-section (the cross-section being in the plane perpendicular to the longitudinal axial direction X of the cable, i.e. the cross- : section may be considered as a radial cross-section of the cable 20). The outer * *** sheath 11 can be considered as comprising a core-enclosing part 12 that encloses the conducting core structure 10 and a protruding part (i.e. protrusion) *..* * 14, each extending longitudinally along the axial direction X, i.e. along the longitudinal direction of the cable 20. In effect the protrusion 14 extends the cross-sectional profile of the outer cover 11 in comparison to the cross-sectional profile of the outer sheath of a conventional mains power supply lead.

In this embodiment the protrusion 14 provides a concave, hollow groove 16 (which may also be termed a slot, for example). The groove 16 extends longitudinally along the axial direction X, i.e. along the longitudinal direction of the cable 20. The groove 16 is such that the groove has an inner portion 1 6a wider than the width of a longitudinally-extending opening 1 6b of the groove 16. The longitudinally-extending opening 1 6b of the groove 16 is defined by the two cross-sectional ends of the protrusion 14, i.e. the two ends of the "C -shape" of the cross section of the outer sheath 11 of the cable 20.

The function of the protrusion 14 is to provide a means allowing the cable to be readily and uniformly attached to supporting structures as will be explained in more detail below with reference to Figure 3.

Figure 3 is a schematic illustration of the cable 20 applied to the light fitting 1, which, as described earlier with reference to Figure 1, comprises a light unit 4 suspended from a ceiling rose 2 by rods 6.

The above described structure of the cable 20, and in particular the inclusion of the protrusion 14, functions to allow attachment of the cable 20 to one of the rods 6 longitudinally along the axial direction X of the cable 20. In more detail, during installation the opening between the two ends of the "C -shape" of the cross section of the outer sheath 11 of the cable 20 are pushed over or around the rod 6 to clamp the rod 6 (either partially or wholly, depending on the relative cross-sectional dimensions of the groove 16 and the rod 6) in the groove 16 making use of the resilient nature of the outer sheath material. * ***

: Preferably the relative cross-sectional dimensions of the groove 16 and the rod 6 *.*S * * are such that a snug fit is achieved between them, i.e. the diameter of the rod 6 is approximately equal to the width of the inner portion 16a of the groove 16, for ***

* example. S..

However, adequate attachment may be achieved even if this is not the * case. For example, even if the diameter of the rod 6 is smaller than the width of the inner portion 16a of the groove, then, provided that the diameter of the rod 6 is larger (or at least not significantly) smaller than the width of the longitudinally-extending opening 1 6b of the groove, the rod 6 will be retained fully inside the -11 -groove 16, i.e. the cable 20 will remain attached to the rod 6, albeit with the possibility that e.g. the light unit 4 will contribute in some cases to retaining the cable's position in the longitudinal direction.

Also for example, even if the diameter of the rod 6 is larger than the width of the inner portion 1 6a of the groove, the cable 20 can still be adequately fixed to the rod 6 due to the material properties of the outer sheath 11, in particular the resilience of the outer sheath 11, allowing the protrusion 14 to grasp or hold the rod 6. This holding can be further enhanced by a barb, latch or clamp function provided by the two ends of the "C -shape" of the cross section of the outer sheath 11 of the cable 20.

Thus, in this exemplary application of the cable 6 as illustrated in Figure 3, once the cable 20 has been fitted onto the rod 6, the protrusion 14 of cable 20 encloses (either fully or partially) the rod 6 so that the cable 20 is longitudinally attached to, and lies flush or uniformly with, the rod 6. Thus the cable 20, and in particular the protrusion 14 allows the cable 20 to be easily and uniformly clipped onto the rod 6 of the light fitting 1.

The cable 20 provides various advantages, including the following.

An electrician installing the light fitting 1 is able to attach conducting elements 102, 104, 106 within the cable 20 to a mains connection block more easily than with conventional cables since the cable 20 can be supported by the rod 6 prior to the electrician connecting the conducting elements 102, 104, 106 to the mains connection block. Therefore the electrician does not have to hold or otherwise secure the cable relative to the light fitting 1 prior to electrical * connection. S..

Also, since the cable 20 can be supported by the rod 6 along the whole length of the rod, or at least substantially the whole length of the rod, or in any event at least a major part of the length of the rod, e.g. over 95%, or over 90%, or over 75%, or over 50% of the length of the rod (depending on how accurately a cable length can be cut relative to the length of the rod 6), once the light fitting 1 -12 -has been installed the light fitting 1 can be cleaned and maintained with less risk of the cable 20 being exposed to accidental disconnection or damage.

Also, as the cable 20 lies flush with the rod 6, there is no longer a problem of inconsistent installation between different light fittings.

Additionally, as cables are often relatively cheap in comparison to light fittings, the cable may be fitted to the other rods, without any electrical connections being made, in order to provide an even distribution of weight. This would also provide a consistency as to physical degradation of the supports of the light fitting, i.e. if exposed rods otherwise would tarnish, then by fixing cable to all three rods (in this example) such tarnishing would not lead to two supports (exposed rods) being different to the third support (the cable-attached rod). This approach of fixing cable to all the rods would also make all of the rods look the same which would be aesthetical'y pleasing. In this case, the designer may specify a material of the cable outer cover 11 offering a particular aesthetic appearance or physical characteristic, e.g. an easy-to-clean material.

Further embodiments of cables of the present invention will now be described with reference to Figures 4-12. Where applicable, the same reference numerals have been used to denote the same constituent parts of the cable as those indicated in Figure 2. Unless otherwise stated, details of the cables, including the materials used to provide each of the constituent parts of the cable, and the method of manufacture of the cables, are as described earlier for cable I... * *

of Figure 2. Unless stated otherwise, the conducting core structure 10 is the same as that described with reference to Figure 2, although for ease of drawing S...

* internal details of the conducting core structure 10 are not shown in Figures 4-12.

Also, in Figures 4-12, only the cross-section of the cable perpendicular to its *SS* **,,. longitudinal direction is shown, however it will be appreciated that the cables shown do in fact extend longitudinally as per the longitudinal extension in the axial direction X as shown in the more detailed Figure 2.

-13 -Figure 4 is a schematic cross-sectional illustration of a cable 40 in accordance with a further embodiment of the present invention. The cable 40 comprises a conducting core structure 10 embedded in an insulating outer sheath 11. The details of these are the same as were described above for the first embodiment with reference to Figure 2, except for details of the cross-sectional shape of the outer sheath 11 as will now be described below.

As shown in Figure 4, the outer sheath 11 of the cable 40 has an approximately "0 -shaped" cross-section (the cross-section being in the plane perpendicular to the longitudinal direction of the cable 40). The outer sheath 11 can be considered as comprising a core-enclosing part 12 that encloses the conducting core structure 10 and a protruding part (i.e. protrusion) 14, each extending along the longitudinal direction of the cable 40. In effect the protrusion 14 extends the cross-sectional profile of the outer cover 11 in comparison to the cross-sectional profile of the outer sheath of a conventional mains power supply lead.

In this embodiment the protrusion 14 provides a concave, hollow groove 16 (which may also be termed a tube, for example). The groove 16 extends along the longitudinal direction of the cable 20. A narrow slot 42 extends from the groove to the outer rim of the outer sheath 11, i.e. to the outer rim of the protrusion 14. A notch 44 is provided at the outer end of the slot 42.

The function of the protrusion 14 is to provide a means allowing the cable to be readily and uniformly attached to supporting structures. This is achieved by pressing the slot 42, in particular the notch 44, against a supporting structure (for example a rod 6 as shown in Figures 1 and 3) such that the outer sheath 11 either side of the slot 42 is pushed apart so that the support structure passes into the groove 16 (or if the support structure is fixed, such that the cab'e 40 moves relative to the support structure such that the groove 16 is positioned around the support structure).

-14 -Thus the general advantages achieved by the cable 20 described earlier with reference to Figures 2 and 3 are also achieved by the cable 40 of this embodiment. Additionally, provided the support structure is of no greater diameter or width than the diameter or width of the groove 16, then by virtue of the protrusion 14 containing only the narrow slot 42 at its exterior, the outer cover 11 will almost completely enclose the support structure 6. Thus the outer cover 11 acts as a protective layer around the support structure. Indeed, in a further embodiment, the narrow slot 42 and the resilience of the material of the outer sheath 11 may be such that the slot 42 is closed, i.e. the ends of the protrusion at the slot 42 press themselves together, such that a form of seal is provided. In this case, once the cable 40 is attached to the support structure, the support structure is fully enclosed and sealed from the outside by the cable 40.

In either case above, the material for the outer cover 11 of the cable 40 may be selected to provide some mechanical supporting effect.

Additionally, in either case above, the cable will present an almost visually uniform appearance around the full circumference of the outer cover.

In this embodiment the notch 44 is provided to help guide or align the slot 42 onto the support structure at the start of the process of pressing the slot 42 against the support structure such that the slot 42 wUl open as the support structure presses against it. However, in other embodiments the notch 44 may be * .* omitted, and the process implemented without the additional assistance of the * *�' guiding function of the notch 44. Yet another possibility is that instead of the notch 44 being provided, a line or other marking is provided at the outer rim of the slot 42 to provide a visual indication to an electrician installing the cable.

* 25 Figure 5 is a schematic cross-sectional illustration of a cable 50 in accordance with a further embodiment of the present invention.

The cable 50 comprises a conducting core structure 10 embedded in an insulating outer sheath 11. The details of these are the same as were described -15 -above for the earlier embodiments, except for details of the cross-sectional shape of the outer sheath 11 as will now be described below.

As shown in Figure 5, the outer sheath 11 of the cable 50 has a cross-sectional form that comprises an approximately "0-shaped" cross-section part attached to an approximately "C-shaped" part (the cross-section being in the plane perpendicular to the longitudinal direction of the cable 50). The approximately "0-shaped" part encloses the conducting core structure 10, i.e. the approximately "0-shaped" part of the outer sheath 11 may be termed the core-enclosing part 12 of the outer sheath 11. The approximately "C-shaped" part may be termed a protrusion 14. In effect the protrusion 14 extends the cross-sectional profile of the outer cover 11 in comparison to the cross-sectional profile of the outer cover of a conventional mains power supply lead.

The protrusion 14 provides a concave, hollow groove 16 (which may also be termed a slot, for example). The groove 16 extends along the longitudinal direction of the cable 20. The groove 16 is such that the groove has an inner portion 1 6a wider than the width of a longitudinally-extending opening 1 6b of the groove 16. The longitudinally-extending opening 1 6b of the groove 16 is defined by the two cross-sectional ends of the protrusion 14, i.e. the two ends of the "C -shape" of the cross section of the outer sheath 11 of the cable 50.

The function of the protrusion 14 is to provide a means allowing the cable to be readily and uniformly attached to supporting structures, in a manner corresponding to that described earlier with reference to Figure 3.

Where the core-enclosing part 12 of the outer sheath 11 meets the * protrusion 14 of the outer sheath there is an external channel 52 where the external width of the outer sheath 11 is narrower than the widths of each of the core-enclosing part 12 and the protrusion 14. The external channel 52 allows *:*. easy separation of the protrusion 14 from the core-enclosing part 12. This is provides convenience and adaptability for installation of the cable 50. For example, when installing the cable 50 on the light fitting 1 describe earlier with reference to Figures 1 and 3, an electrician may first push fit the protrusion 14 of the cable 50 onto a rod 6 along the length of the rod 6. Then, in order to connect the conducting elements to the voltage supply, the electrician can easily strip away any unwanted extent of the protrusion 14 so that he can feed only the core-enclosing part 12 through the ceiling rose 2 of the light fitting 30 to a voltage connection block (not shown). Any unwanted extent of the protrusion 14 at the other end of the cable 50 may also be stripped away easily when connecting the conducting elements to terminals on the light unit 4.

In fabrication of the cable 50, the external channel 52 may be formed at the same time as the outer sheath 11 of the cable 50 is provided or otherwise formed into the desired shape. Another possibility is that the external channel portion 52 could also be formed after the outer sheath 11 has been formed, for example by scoring or other means of removing excess outer sheath material.

In other embodiments, other shapes (i.e. other than "0-shaped" and for other than "C-shaped" may be employed to provide an external channel between a core-enclosing part and a protrusion part, where the external channel facilitates removal of a length of the protrusion from the core-enclosing part. Moreover, in other embodiments, other shapes or arrangements that do not involve an external channel as such may be used to provide easy removal of a length of the protrusion from the core-enclosing part -for example weakening voids may be included in the joining area between the protrusion and the core-enclosing part.

*. Figure 6 is a schematic cross-sectional illustration of a cable 60 in accordance with a further embodiment of the present invention.

The cable 60 comprises a conducting core structure 10 embedded in an insulating outer sheath 11. The details of these are the same as were described above for the earlier embodiments, except for details of the cross-sectional shape S...

of the outer sheath 11 as will now be described below. Sd

* As shown in Figure 6, the outer sheath 11 of the cable 60 has a cross-sectional form that comprises an approximately "0-shaped" part enclosing the -17 -conducting core structure 10, and which may be termed the core-enclosing part 12 of the outer sheath 11, and a protrusion 14. In effectthe protrusion 14 extends the cross-sectional profile of the outer sheath 11 in comparison to the cross-sectional profile of the outer sheath of a conventional mains power supply lead.

In this embodiment the protrusion 14 is solid and is shaped so as to allow engagement with a matching slot or groove in a mating supporting member such as supporting member 61.

The protrusion 14 may be approximately triangular in cross-section with a pointed extension 64 shaped to facilitate engagement with the mating slot or groove in a supporting member, e.g. the supporting member 61.

The protrusion portion 14 may also be provided with optional flanges 66 surrounding the narrow pointed portion 64 of the triangular protrusion to facilitate retention within a mating groove or slot in a supporting member, e.g. the supporting member6l.

As with the earlier embodiment described with reference to Figure 5, the core-enclosing part 12 and the protrusion 14 may be partially separated from each other by an external channel 62 for facilitating the separation of lengths of the core-enclosing part 12 from the protrusion 14 e.g. to make it easier for an electrician to connect the conducting elements at end portions of a length of the *,, 20 cable 60 as required.

Figure 7 is a schematic cross-sectional illustration of a cable 70 in * .** * * accordance with a further embodiment of the present invention.

The cable 70 comprises a conducting core structure 10 embedded in an insulating outer sheath 11. The details of these are the same as were described above for the earlier embodiments, except for details of the cross-sectional shape of the outer sheath 11 as will now be described below. S. S

: As shown in Figure 7, the outer sheath 11 of the cable 70 has a cross-sectional form that comprises an approximately "0-shaped" cross-section part attached to two separate approximately "C-shaped" parts (the cross-section -18 -being in the plane perpendicular to the longitudinal direction of the cable 70). The approximately "0-shaped" part encloses the conducting core structure 10, i.e. the approximately "0-shaped" part of the outer sheath 11 may be termed the core-enclosing part 12 of the outer sheath 11. The approximately "C-shaped" parts may be termed respective protrusions 14. In effect the protrusions 14 extend the cross-sectional profile of the outer cover 11 in comparison to the cross-sectional profile of the outer cover of a conventional mains power supply lead.

The protrusions 14 each provide a respective concave, hollow groove 16 (which may also be termed a slot, for example). The grooves 16 extend along the longitudinal direction of the cable 20. The grooves 16 are such that each groove has an inner portion 1 6a wider than the width of a longitudinally-extending opening 1 6b of the groove 16. The longitudinally-extending opening 1 6b of each groove 16 is defined by the two cross-sectional ends of the respective protrusion 14, i.e. the two ends of the respective "C shape".

The function of the protrusions 14 is to provide a means allowing the cable to be readily and uniformly attached to one or more supporting structures.

Similar to various of the earlier described embodiments, the core-enclosing part 12 and the protrusions 14 may be partially separated from each other by external channels 72 for facilitating the separation of lengths of one or both of the protrusions from the core-enclosing part 12 e.g. to make it easier for an electrician to connect the conducting elements at end portions of a length of the cable 60 as required.

A particular advantage of the cable 70 of this embodiment is that the cable can be supported simultaneously by two support members. For example, in overhead wiring applications, the support members could be two parallel metal *.. : wires or struts, thus enabling overhead cabling to be routed safely, neatly and inexpensively across long distances without the need for additional cable trunking enclosures or fixing means.

S *SS

S * .S*

S *SS* *5 5 * * S * S.

In this embodiment the two protrusions are placed at opposite sides of the core-enclosing part. However, this need not be the case, and in other embodiments they may be placed at other relative positions. Also, in other embodiments, more than two protrusions may be provided -for example three equally spaced protrusions would be particularly stable with regard to unwanted movement or twisting.

Yet further embodiments may be provided by providing two or more protrusions for any of the embodiments described above with respect to Figures 2, 4 and 6.

In each of the above described embodiments, the cable has only one conducting core structure. In further embodiments, the cable may comprise plural conducting core structures, with the different conducting core structures being positioned in close proximity with each other, and in particular positioned together within the above described core-enclosing part of each respective embodiment described above. Each conducting core structure contains one or more separate conducting elements as defined earlier. Two particular embodiments along these lines will now be described with reference to Figures 8 and 9.

Figure 8 is a schematic cross-sectional illustration of a cable 80 according to a further embodiment of the present invention. The cable 80 comprises plural conducting core structures 10 embedded in an insulating outer sheath 11. The details of these are the same as were described above for the earlier embodiments, except for the inclusion of plural conducting core structures 10 and details of the cross-sectional shape of the outer sheath 11 as will now be described below.

**. 25 The cable 80 comprises plural conducting elements 10 arranged adjacent , each other in a relatively flat portion of the outer sheath 11, such as in known ribbon cables. The relatively flat portion may be termed the core-enclosing part *: 12 of the outer sheath 11. The cross-sectional shape of the outer sheath 11 S* further comprises a protrusion 14. The protrusion 14 has an approximately "C -**** S... *S * * . * .* -20-

shaped" cross-section (the cross-section being in the plane perpendicular to the longitudinal direction of the cable 80). In effect the protrusion 14 extends the cross-sectional profile of the outer sheath 11 in comparison to the cross-sectional profile of the outer sheath of a conventional ribbon cable.

In this embodiment the protrusion 14 provides a concave, hollow groove 16 (which may also be termed a slot, for example). The groove 16 extends longitudinally along the longitudinal direction of the cable 80. The groove 16 is such that the groove has an inner portion 1 6a wider than the width of a longitudinally-extending opening 16b of the groove 16. The longitudinally-extending opening 1 6b of the groove 16 is defined by the two cross-sectional ends of the "C-shape" of the protrusion 14.

The function of the protrusion 14 is to provide a means allowing the cable to be readily and uniformly attached to supporting structures, as was described for the earlier described embodiments.

Optionally an external channel 82 may be provided where the core-enclosing part meets the protrusion 14. Similar to various of the earlier described embodiments, the core-enclosing part 12 and the protrusions 14 may be partially separated from each other by the external channel 82 for facilitating the separation of lengths of one or both of the protrusions from the core-enclosing part 12 e.g. to make it easier for the conducting elements at end portions of a length of the cable 60 to be connected to external connections as required.

Figure 9 is a schematic cross-sectional illustration of a cable 90 according to a further embodiment of the present invention. The cable 90 comprises plural conducting core structures 10 embedded in an insulating outer sheath 11. The details of these are the same as were described above for the earlier embodiments, except for the inclusion of plural conducting core structures 10 and details of the cross-sectional shape of the outer sheath 11 as will now be described below. *S..

S S..

S *S.I * .

S

S

-21 -The cable 90 comprises plural conducting elements 10 arranged adjacent each other in a relatively flat portion of the outer sheath 11, such as in known ribbon cables. The relatively flat portion may be termed the core-enclosing part 12 of the outer sheath 11. The cross-sectional shape of the outer sheath 11 further comprises two protrusions 14, one at each (cross-sectional) end of the core-enclosing part 12. The protrusions 14 each have an approximately "C -shaped" cross-section. In effect the protrusions 14 extend the cross-sectional profile of the outer sheath 11 in comparison to the cross-sectional profile of the outer sheath of a conventional ribbon cable.

In this embodiment the protrusions 14 each provides a respective concave, hollow groove 16 (which may also be termed a slot, for example). Each groove 16 extends longitudinally along the longitudinal direction of the cable 90.

The grooves 16 are such that each groove has an inner portion 1 6a wider than the width of a longitudinally-extending opening 1 6b of the groove 16. The longitudinally-extending opening 1 6b of each groove 16 is defined by the two cross-sectional ends of the "C-shape" of that groove's protrusion 14.

The function of the protrusions 14 is to provide a means allowing the cable to be readily and uniformly attached to one or more supporting structures, as was described for the earlier described embodiments.

A particular advantage of the cable 90 of this embodiment is that the cable can be supported simultaneously by two support members. For example, in overhead wiring applications, the support members could be two parallel metal wires or struts, thus enabling overhead cabling to be routed safely, neatly and inexpensively across long distances without the need for additional cable trunking enclosures or fixing means.

* In this embodiment the two protrusions are placed at opposite ends of the * *S.

core-enclosing part. However, this need not be the case, and in other embodiments they may be placed at other relative positions. Also, in other embodiments, more than two protrusions may be provided -for example in * *.SS * S *.SS * * * S * ** addition to a protrusion at each (cross-sectional) end of the core-enclosing part, one or more further protrusions could be provided at intervals along the (cross-sectional as opposed to longitudinal) length of the core-enclosing part to alleviate sagging, especially where there are a large number of conducting elements and hence the core-enclosing part is relatively wide.

In each of the above described embodiments, broadly speaking the conducting core structure or structures is/are located in a separate area of the (cross-section of the) cable to that area or areas which are shaped to provide the attaching means, e.g. the protrusion or protrusions described above. In further embodiments, the conducting core structure, or in the case of plural conducting core structures, some or all of the conducting core structures, are iocated in an area of the (cross-section of the) cable which is shaped to provide or to contribute to the attaching means e.g. a protrusion or protrusions. Three particular embodiments along these lines will now be described with reference to Figures 10 -13.

Figure 10 is a schematic cross-sectional illustration of a cable 100 in accordance with a further embodiment of the present invention.

The cable 100 comprises plural conducting core structures 10 embedded in an insulating outer sheath 11. The details of these are the same as were described above for the earlier embodiments, except for the location of the plural conducting core structures 10 and details of the cross-sectional shape of the outer sheath 11 as will now be described below.

As shown in Figure 10, the outer sheath 11 of the cable 100 has an approximately "C-shaped" cross-section (the cross-section being in the plane perpendicular to the longitudinal direction of the cable 100). The outer sheath 11 * * S S. * . can be considered as comprising a main part 112 of the C-shaped cross-section, and two ends 114 of the C-shaped cross-section (which may in combination be :r considered as a protrusion) extending the cross-sectional profile of the outer * *5* * * *SS S * *b*' S. * * S S * S. -23 -cover 11 in comparison to the cross-sectional profile of the outer sheath of a conventional mains power sup ply lead.

In this embodiment the two ends 114 of the C-shaped cross-section and the main part 114 of the C-shaped cross-section together provide a concave, hollow groove 16 (which may also be termed a slot, for example). The groove 16 extends longitudinally along the longitudinal direction of the cable 100. The groove 16 is such that the groove has an inner portion 1 6a wider than the width of a longitudinally-extending opening 1 6b of the groove 16. The longitudinally- extending opening 1 6b of the groove 16 is defined by the two ends 114 of the C-shaped cross-section of the outer sheath 11 of the cable 100. The function of the C-shape of the outer sheath 11 of the cable 100, and in particular the ends 114 of the C-shape and the provision of the groove 16, to provide means allowing the cable 100 as was described for the earlier described embodiments.

As well as the general advantages described above for the earlier embodiments, this embodiment tends to provide further advantages arising from locating conducting core structures 10 in the attaching part of the cable 100. For example, the amount of insulation between each conducting element 10 can be increased. Another possible advantage of this embodiment is that the attaching part, i.e. the ends 114 of the C-shaped cross-section may be provided with increased strength by the inclusion of the conducting core structures, thus making the attachment between the cable 100 and a supporting structure stronger and more firmly located.

In further embodiments further detailed cross-sectional shapes of the outer sheath may be provided, for example as follows.

*... 25 Figure 11 is a schematic cross-sectional illustration of a cable 110 in * * . *.* accordance with a further embodiment of the present invention. The cable 110 is the same as the cable 100 of the embodiment described with reference to Figure 10, except that the outer profile of the main part 112 of the C-shaped cross-S...

section of the outer sheath 11 is shaped to substantially uniformly surround the *.*.

S S... *5 * S * * * S.

-24 -conducting core structure 10 contained therein. This shape advantageously requires less material for the outer sheath 11.

Figure 12 isa schematic cross-sectional illustration of a cable 120 in accordance with a further embodiment of the present invention. The cable 120 is the same as the cable 110 of the embodiment described with reference to Figure 11, except that the outer profile of the overall outer sheath 11 is shaped so that a symmetrical cross-sectional shape of the outer sheath 11 is provided, with e.g. three identical areas 122 of the outer sheath 11 each surrounding a respective conducting core structure 10, so as to further provide three grooves 16, each groove 16 being between a respective pair of identical areas 122 of the outer sheath 11. Each groove 16 extends longitudinally along the longitudinal direction of the cable 120. Each groove 16 is such that the groove has an inner portion 1 6a wider than the width of a longitudinally-extending opening 1 6b of the groove 16. Each identical area 122 may be considered as a protrusion. This embodiment tends to provide the same advantages as the embodiment described with reference to Figure 11, and furthermore tends to provide a further advantage that three attaching grooves are provided and hence an installer has a choice of grooves and so can e.g. fix the cable to a supporting structure without needing to twist the cable to align a specific groove to the supporting structure.

This may be particularly advantageous if a supporting structure itself is not straight. In other embodiments other plural numbers of identical areas/grooves (i.e. not necessarily three) may be provided. Furthermore, it is not essential that the areas 122 are identical, for example if the conducting core structures 10 were of different widths, the respective areas of the outer sheath around the different **. 25 core structures may themselves be provided in different sizes. * *:

Figure 13 is a schematic cross-sectional illustration of a cable 130 in accordance with a further embodiment of the present invention. The cable 130 is broadly similar to the cable 100 of the embodiment described with reference to Figure 10, except that a larger number of conducting core structures 10 are 1* **** ** * * * * * ** -25 -provided within the outer sheath 11, approximately continuously adjacent from one end of the cross-section of the outer sheath 11 to the other end, and the cross-sectional width of the outer sheath his approximately equal along the C-shape, except where the ends 134 of the C-shaped cross-section are shaped for fixing. Thus this cable 130 may be employed, for example, as an alternative to conventional ribbon cable, with the advantage of its cross-sectional shape providing a means for fixing to a support structure was described for the earlier described embodiments.

As expJained above for the various embodiments of cable, the cable is provided with a shape or means for fixing the cable to a supporting structure. In the above description, this has been described, by way of example, in the context of fitting a power supply cable to a structure, i.e. rod or strut, of a light fitting.

However, it will be appreciated that the cable may be fitted to any type of structure, as required according to the circumstances of the installation of the cable. Another possibility is that the fixing means of the above described cables may be used to fix the cable to a further cable e.g. the C-shaped protrusion of the cable embodiment of Figure 2 may be used to attach the C-shaped cable to a further cable, for the purpose of bundling plural cables together in an ordered manner. This may reduce or remove the need for using e.g. cable ties for such a purpose. The further cable may itself be a cable with fixing means provided. In this case, yet another cable may be fixed to the further cable, and so on i.e. a large number of cables as described above can be fixed to each other.

Figure 14 is a schematic illustration of a cable support fixture 140 with a plurality of cables 20 as described earlier with reference to Figure 2 attached thereto. Consistent with earlier Figures 2 and 4-13, the support fixture 140 and * the cables 20 are shown in cross-section perpendicular to the longitudinal direction of the cables 20. The cable support fixture 140 comprises several support members 142 and a frame 141. Each support member 142 is pivotally 4*I* connected to the frame 141 at a respective pivot point 143. The support * .eS * * **.* ** S * S I e *.

-26 -members 143 are arranged essentially in parallel to each other. The different support members may be accessed by moving the support members about the pivot points, as indicated in dotted lines in Figure 14 for movement of the top support member 142 in the direction indicated by the arrow with reference numeral 146.

Each support member 142 is provided with a plurality of support structures 144. These may be on both sides, or just one side, of the support member. In the present embodiment, the top and bottom support members only have support structures on one side, i.e. the side that faces in wards in the cable support structure, whereas the central support member has support structures on both sides. This provides a compromise between on the one hand optimising the number of surfaces with support structures and on the other hand not having exposed cables on the outer ends of the cable support fixture. Each support structure 144 is shaped for attachment with the attachment protrusion of the particular cable to be attached. Thus, in this example where the cable support structure 140 is intended to be used with the type of cable described above with reference to Figure 2, each support structure 144 is shaped in cross-section in the form of a protruding nodule to approximately match, i.e. be surrounded by, the groove 16 of the cable 20. However, in other embodiments, other shapes of support structure are provided to match the cable shape. The support structures 144 extend longitudinally so that the cables 20 can be fixed along their longitudinal directions. In Figure 14, by way of example, some of the support structures 144 are shown with a cable 20 attached thereto, and some are shown without a cable 20 attached thereto.

*. 25 One advantage that tends to be offered by the cable support fixture 140 is that, as a result of the pivotable arrangement of the support members 142 each cable 20 within the cable support fixture 140 can be easily accessed.

The cable support fixture may be applied in the domestic and commercial *.

construction industries for installing power and/or communications cabling. Other * *** S * *55* *5 5 * S S * ** -27 -suitable implementations include marine and aerospace environments, where the compactness of the fixture may be particularly advantageous in certain applications.

It will further be appreciated that the possibility for cable support structures such as shown In Figure 14 to be provided for use with the cables described above tends to represent another potential advantage of the cables themselves.

It will be appreciated that in other embodiments a large variety of cable support fixtures may be provided for providing convenient and compact fixing thereto of the cables described above with reference to Figures 2-13. The details * of any given cable support structure will vary according to the application requirements and the characteristics of the cable required to be fixed. For example, the support structures (i.e. corresponding to the nodular support structures 144 in the embodiment described with reference to Figure 14) will be shaped and/sized to match the attaching means, e.g. grooves and/or protrusions of the cable (e.g. in the case of a cable with a "solid" type protrusion such as shown in Figure 6, then a support structure may be in the form of a groove or slot).

Generally, for examp'e, different numbers, ayouts etc of support members may be provided according to the application. For example, in a simple version, there may only be one support member. For example one or all of the support members may not be hinged. For example the various support members may not be parallel to each other.

The above described embodiments may be manufactured using any suitable conventional cable manufacturing method, except adapted to provide the * * 2'S above described shapes of the outer profile of the cross-section of the outer *SS S. ! sheath, and the described positioning of the conducting elements(s) within the * shape of the cross-section of the outer sheath. S**

Further details of certain examples of such conventional cable manufacturing methods will now be described by way of example. S..' S. *

S

-28 -Cables may be fabricated by means of extruding at least one layer of a plastic such as PVC or a thermoplastic or other polymer around a conducting element or conducting core structure. One such method is described in above mentioned WO/2006/1 14118.

Depending on the desired type of cable and materials to be used, one or more conducting element is supplied to an extrusion press machine which comprises at least one extrusion die section and a channel for feeding smelted thermo-plastic polymer or other thermo-stable material into the extrusion die section.

A typical extrusion process may comprise feeding a conducting material through a first die stage having an opening corresponding to the desired diameter of the conductor to form the conducting element. The conducting element is then fed to a second extrusion die stage which has an opening with a diameter corresponding to the desired diameter of the insulating sheath. Between the first die stage and the second die stage there is a channel through which a thermo stable insulating material is forced under the application of pressure. As the insulating material is subjected to pressure, the pre-formed conducting element is fed through the centre of the opening in the second die. As the insulating material is forced through the second die opening it encircles the conducting element. The conducting element and insulating material are continuously fed into the second die stage together. On exiting the second die stage, the extruded insulating material cools around the conducting element to completely enclose the conducting element in an insulating sheath.

As is immediately apparent from the above description, more insulating ::.5 layers can be formed around the sheathed conductor by feeding the sheathed conductor and additional material into further stages of dies and channels *** selected in accordance with the desired final composition of the cable.

Figure 15 is a schematic illustration of an embodiment of an extrusion die which may be used in the manufacture of a cable 20 of the type described

I S.I

I

SI S **

-29 -above with reference to Figure 2. The extrusion die 150 comprises an opening 152. The opening is shaped with an outer profile in the required cross-section of the outer sheath of the cable to be manufactured.

The cable may be manufactured as follows. The conducting core structure 10 is formed in conventional fashion as described above using a first process die.

The extrusion die 150 shown in Figure 15 is used in the process as a second process die. More particularly the conducting core structure 10 is fed through the opening 152 of the extrusion die 150.

As in the conventional processes described above, between the first process die and the extrusion die 150 (acting as the second process die) an insulating material such as a thermoplastic polymer is fed under pressure along a channel disposed for feeding the polymer around the conducting core structure through the opening 152. The extrusion die 150 is of sufficient thickness in the direction of feed to enable the polymer material to flow around the conducting core structure 10 so as to completely enclose the conducting core structure 10 before cooling to form the outer sheath 11 of the cable 20.

The speed of feeding the conducting element 10, the dimension of the polymer feed channel, the composition, the viscosity of the fluid polymer, the applied pressure and the dimensions of the opening 142 and the thickness in the direction of material flow of die 140 are selected in conventional fashion in accordance with the desired electrical, chemical and mechanical properties of the cable.

In the above embodiments the conducting element or elements are ***, electrically conducting and the cables are therefore electrically conducting *..*5 cables. However, in other embodiments, the conducting element or elements are optical fibre, and the cables are light conducting or guiding optical fibre cables.

S

It is noted that many terms are used in with overlapping meaning in the 4* technical field of cables, including variation from country to country, in particular with regard to the use of the terms "core" and "wire". For example, the term "wire"

S S... * S * *5

-30 -is often used in this field to refer to an arrangement made of plural strands of wire twisted together. Hence the following points are made for clarification. In the above embodiments, each conducting element may comprise a single conductor e.g. wire, or may be formed from a plurality of strands of conductor e.g. wires twisted together or otherwise joined or located together to provide a single conducting element in terms of function. The terminology "conducting element" as used herein is therefore to be understood to refer to a conducting structure within a cable along which any power or signal applied to a particular conducting element at one end of the cable is conveyed along the longitudinal axial direction of the cable by that conducting element but is not conveyed along the cable by any other conducting element that is present in the cable. Furthermore, plural such conducting elements, if insulated from each other, may be bundled together in what is referred to herein as a conducting core structure. In some embodiments the cable has only one conducting core structure. In other embodiments, the cable has plural conducting core structures. What is referred to (at least in the UK) as, for example, three-core cable, strictly means three-conducting elements in terms of the terminology used herein, which three conducting elements in some examples are in the form of a single bundled together conducting core structure and in some examples the different conducting elements are located in separate individual conducting core structures.

The above clarifications also apply in corresponding manner for optical fibre embodiments.

In the above embodiments the outer sheath is made of PVC. Other * S **s possible polymers include the following: polyethylene (FE), polypropylene (PP), * and thermoplastic propylene/ethylene copolymers. Other possible materials include natural rubbers, butyl rubbers and ethylene copolymers.

In the above embodiments the outer sheath is a single continuous block of material. However, in other embodiments, an effectively solid outer sheath may -. S. * S * * t

-31 -be built up by providing a plurality of layers of insulating material. In this case, the plural layers may be all of the same material, or may be of differing materials.

Examples of materials which may be used are paper, ceramic, and foam, as well as thermally stable materials suitable for extrusion. Generally the outer layer is made of a polymeric composition. Examples of suitable polymers are: In the above embodiments, the overall cross-sectional shape of the outer sheath, including the protrusion or other fixing providing shape, is manufactured integrally as one part. However, in other embodiments, the protrusion or other fixing providing shape may be manufactured as a separate part which is bonded to the conventionally-shaped outer sheath of a conventional cable.

With regard to the use herein of the terminology "outer sheath", it will be appreciated that the term "outer" is used herein to mean outside of the conducting element (and where appropriate outside any inner or intermediate sheaths), and is not used herein in an exclusive sense of having to be being the very final outer layer of a cable. In other words, it will be appreciated that in further embodiments one or more thin coverings may further be provided outside of the outer sheath (e.g. for additional water proofing).

It will be appreciated that the above embodiments are examples of cables in which the outer sheath of the cable has a cross-sectional shape that provides a capability for the cable to be attached or clipped, e.g. by push-fitting, to structures such as support structures. Thus the protrusions, grooves, slots and other shapes described are examples of implementations of providing a clipping function to the cables. Thus, in other embodiments, other forms of integrated clip or push-fit shapes may be provided to the cross-sectional shape of the outer sheath of the cable. jS

In the above embodiments the protrusion (or other features providing *.S.

fixing means) is provided along the whole longitudinal i.e. axial direction of the * cable. However, in other embodiments, the protrusion (or other features providing * fixing means) is provided along only part of the longitudinal i.e. axial direction of **** * * * -* -32 -the cable. For example, for cable manufactured to predetermined lengths, the protrusion (or other features providing fixing means) may be provided at one or both end portions of the cable only. Another possibility is that the protrusion (or other features providing fixing means) may be provided intermittently along the length of the cable.

Although, the cable support fixture of Figure 14 comprises several support members attached to a support frame, this is not essential. For example, a simple embodiment of the cable support fixture may comprise just one support member. Likewise, the one (or in other embodiments, plural) support members may comprise only one support structure (e.g. nodule) each. * S * *, S * S S.. *S*. **i S.. S... * . S... S. * S **

Claims (42)

1. -33 -CLAIMS1. A cable, comprising: a conducting element surrounded by an insulating sheath, wherein the insulating sheath is shaped, along at least a part of its longitudinal length, for fixing the cable to a structure.
2. 2. A cable according to claim 1, wherein the insulating sheath comprises a protrusion part of the cross-sectional shape of the insulating sheath.
3. 3. A cable according to claim 1, wherein the protrusion part is substantially C-shaped with a longitudinally extending groove.
4. 4. A cable according to claim 3, wherein the longitudinally extending groove has an inner part and an opening, the opening being smaller than the inner part.
5. 5. A cable according to claim 2, wherein the protrusion part contains a groove for enclosing the structure.
6. 6. A cable according to claim 5, wherein the insulating sheath comprises a slot adjacent the groove, the slot being for closing together once a structure is in the groove so that the insulating sheath surrounds the structure.
7. 7. A cable according to claim 2, wherein a channel is provided between the **s� *.. 5 protrusion part of the insulating sheath and a part of the insulating sheath *
8. S..*,*** enclosing the conducting element, the channel being for facilitating separation of the protrusion part of the insulating sheath from the conducting element part of the insulating sheath. * *.S* *0 * * * * **

   -34 - 8. A cable according to claim 2, wherein the protrusion part comprises an extension and a flange.
9. 9. A cable according to any of claims 1 to 8, wherein the insulating sheath is shaped, along at least a part of its longitudinal length, so as to provide plural means for fixing the cable to structures.
10. 10. A cable according to any of claims 1 to 9, wherein the cable comprises a plurality of conducting elements all provided in a single conducting core structure.
11. 11. A cable according to any of claims 1 to 9, wherein the cable comprises a plurality of conducting elements provided adjacent each other.
12. 12. A cable according to any of claims ito 9, wherein the cable comprises a plurality of conducting elements located in separate parts of the cross-sectional shape of the insulating sheath, wherein at least one of the conducting elements is located in a part of the shape of the insulating sheath that provides fixing.
13. 13. A cable according to any of claims 1 to 12, wherein the insulating sheath is shaped along its entire length, or along substantially its entire length, for fixing the cable to a structure.
14. 14. A cable according to any of claims 1 to 13, wherein the structure is another cable. S.' * .
15. 15. A cable according to any of claims ito 14, wherein the conducting element is an electrical conductor for conducting one of the following: power; S..* data; * . **.S * S*S-35 -power and/or data.
16. 16. A cable according to any of claims 1 to 14, wherein the conducting element is of fibre optics.
17. 17. A cable support fixture comprising a support structure extending along a support member, wherein the support structure is shaped for having a cable according to any of claims 1 to 16 fixed to the support structure by the fixing means.
18. 18. A cabling system comprising a support fixture according to claim 17 and one or more cables according to any of claims 1 to 16 fixed to support structures of the support fixture.
19. 19. An extrusion die for use in manufacturing a cable comprising an insulating sheath around a conducting element; the extrusion die comprising an opening for feeding insulating material through to form the insulating sheath around the conducting element; the opening being shaped so as to provide a shape to the insulating sheath that provides a means for fixing the cable to a structure.
20. 20. A method of installing a cable, wherein the cable is according to any of claims 1 to 16, the method comprising fixing the cable to a structure using the fixing means provided by the shape of the insulating sheath of the cable. * **:::*
21. 21. A method of manufacturing a cable, the method comprising providing an * insulating sheath around a conducting element, wherein the insulating sheath is provided so as to be shaped, along at least a part of its longitudinal length, for **.* fixing the cable to a structure. S.. * * *S*. S. *

    S S S *.

    -36 -
22. 22. A method of manufacturing a cable according to claim 21, wherein the insulating sheath is shaped to comprise a protrusion part of the cross-sectional shape of the insulating sheath.
23. 23. A method of manufacturing a cable according to claim 21, wherein the protrusion part is substantially C-shaped with a longitudinally extending groove.
24. 24. A method of manufacturing a cable according to claim 23, wherein the longitudinally extending groove has an inner part and an opening, the opening being smaller than the inner part.
25. 25. A method of manufacturing a cable according to claim 22, wherein the protrusion part contains a groove for enclosing the structure.
26. 26. A method of manufacturing a cable according to claim 25, wherein the insulating sheath comprises a slot adjacent the groove, the slot being for closing together once a structure is in the groove so that the insulating sheath surrounds the structure.
27. 27. A method of manufacturing a cable according to claim 22, wherein a channel is provided between the protrusion part of the insulating sheath and a part of the insulating sheath enclosing the conducting element, the channel being for facilitating separation of the protrusion part of the insulating sheath from the *..* .. 5 conducting element part of the insulating sheath. *.S. * * S..*,,
28. 28. A method of manufacturing a cable according to claim 22, wherein the protrusion part comprises an extension and a flange. **.. * .S

    S *S

    -37 -
29. 29. A method of manufacturing a cable according to any of claims 21 to 28, wherein the insulating sheath is shaped, along at least a part of its longitudinal length, so as to provide plural means for fixing the cable to structures.
30. 30. A method of manufacturing a cable according to any of claims 21 to 29, wherein the cable comprises a plurality of conducting elements all provided in a single conducting core structure.
31. 31. A method of manufacturing a cable according to any of claims 21 to 29, wherein the cable comprises a plurality of conducting elements provided adjacent each other.
32. 32. A method of manufacturing a cable according to any of claims 21 to 29, wherein the cable comprises a plurality of conducting elements located in separate parts of the cross-sectional shape of the insulating sheath, wherein at least one of the conducting elements is located in a part of the shape of the insulating sheath that provides fixing.
33. 33. A method of manufacturing a cable according to any of claims 21 to 32, wherein the insulating sheath is shaped along its entire length, or along substantially its entire length, for fixing the cable to a structure.
34. 34. A method of manufacturing a cable according to any of claims 21 to 33, wherein the structure is another cable. I... * a,,
35. 35. A method of manufacturing a cable according to any of claims 21 to 34, wherein the conducting element is an electrical conductor for conducting one of the following: power; *..s * a S... *. . * S * a.-38 -data; power and/or data.
36. 36. A method of manufacturing a cable according to any of claims 21 to 34, wherein the conducting element is of fibre optics.
37. 37. A cable substantially as hereinbefore described with reference to the accompanying drawings.
38. 38. A cable support fixture as hereinbefore described with reference to the accompanying drawings.
39. 39. A cable system substantially as hereinbefore described with reference to the accompanying drawings.
40. 40. An extrusion die substantially as hereinbefore described with reference to the accompanying drawings.
41. 41. A method of installing a cable as hereinbefore described with reference to the accompanying drawings.
42. 42. A method of manufacturing a cable as hereinbefore described with reference to the accompanying drawings. *Ss * * . ** . *S*. * . *.S. **** * S..S a... * . S... S. S * S S S.