AU2004200623A1 - Cable ducting - Google Patents

Description

4 P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Invention Title: Cable ducting The following statement is a full description of this invention, including the best method of performing it known to us: Freehills Carter Smith Beadle Melbourne\004437428 Printed 17 February 2004 (14:41) page 2 004435715 2 Cable ducting Field of the invention The invention relates to a cable ducting assembly. In particular, the assembly is adapted for use with cables such as power cables, telecommunication cables and data cables. The invention also relates to a cable guide to define a minimum radius of curvature for cables. A method of retrofitting the cable guide into an existing cable ducting system is disclosed.

Backqround of the invention Cable ducting assemblies have been developed over a number of years for use in buildings and other installations. By having separate electric cable ducting to carry cable it is possible to avoid the need to run cable within the wall cavity which is traditionally carried out during construction. Ducting may be installed on the exterior face of the wall and may conveniently also constitute the skirting board. Clearly, the use of these ducts makes them attractive from a maintenance point of view as well. Since these ducts are external to the wall cavity they allow the cables to be easily accessed.

The ducting commonly in use may have one or more longitudinal chambers depending upon how many services cables) are to be located in it. These separate chambers are needed when the ducting is to house cables used for different purposes. Typically, electric cables relating variously to data processing systems, power supply systems, telecommunication systems and other systems are each isolated in separate chambers within the same duct, by means of a series of rigid, impenetrable, internal walls. This isolation of cables in separate chambers is often required by national regulations. Usually the ducting is manufactured by an extrusion technique and as such the walls may be formed in the original extrusion.

A new standard has been set for data cabling which is known as "category 6" data cabling. Such cabling should be installed with a minimum bend radius.

004435715 3 Otherwise, loss of data can occur and other attenuation effects. This minimum bend rate radius is 25 mm.

Typically, when two cable ducts meet at a corner, they may have a mitred joint. Alternatively, a corner fitting may be installed so that the ends of cable ducts may be cut normal to their respective lengths. Such corner fittings include tongues for securement of the corner fittings to the internal walls of the ducts. The tongues also maintain the separation between the chambers. In either the mitred corner arrangement and the arrangement with the corner fitting, there is the risk that any cable traversing the corner may form a sharp bend which is less than the minimum allowable radius of curvature for category 6 data cabling.

The foregoing prior art discussion is not to be taken as an admission of common general knowledge.

It is an object of the present invention to provide a cable guide and a cable ducting assembly and a method of installation a cable guide which overcomes or at least addresses some of the aforementioned difficulties. Another object of the invention is to at least provide the public with a useful choice.

Summary of the invention In accordance with a first aspect of the present invention there is provided a cable guide for cable ducting having longitudinal chambers divided by internal walls, the cable guide comprising: a top and a bottom; a wall portion having a convex side defining a predetermined minimum radius of curvature for a cable; one or more apertures or gaps disposed intermediate the top and the bottom to receive parts of the internal walls of the ducting.

004435715 4 The cable guide may be appropriate for use with an internal corner.

The one or more apertures may be of any shape. Preferably the apertures are disposed in the wall portion. These apertures enable the cable guide to be inserted into the corner of the cable ducting without any further modification of the internal walls of the ducting. Further, where the corners are provided with corner fittings having tongues which maintain the separation between the chambers of the ducting, the one or more apertures or gaps also may accommodate these tongues and enables the cable guide to be fitted into the corner. The one or more apertures may comprise one or more slots. In a preferred form of the invention, there is a single slot extending across the wall portion. A gap may also be provided below the wall portion.

The cable guide may also be provided with planar side wall portions at each side edge of the wall portion. The slot may extend across the entire wall portion terminating in the side wall portion. Preferably, the side wall portions extend at substantially 900 to each other. However, the cable guide may be constructed of sheet metal enabling the planar side wall portions to be bent at different angles to each other to accommodate corners in the ducting other than right angle corners.

However, the cable guide is not limited to be constructed of sheet metal and may alternatively be cast or moulded. The cable guide may also be constructed of plastic.

Additionally, the cable guide may be provided with one or more retaining flaps extending at substantially 90 to the wall portion. These retaining flaps enable the cable guide to be attached to the internal walls of the ducting.

Preferably, there are two flaps arranged at 900 to each other. Preferably the two flaps are disposed adjacent the lower edge of the wall portion.

The wall portion may be of any shape provided it defines a minimum radius of curvature for a cable. In the most preferred form of the invention, the wall portion is curved. However, the wall portion need not be limited to a curved or 004435715 arcuate shape. The wall portion may be kinked or otherwise not smooth. For example, the wall portion may be fluted to provide strength.

In accordance with a second aspect of the present invention there is provided a method of installing a cable guide for an existing cable ducting assembly comprising at least two cable ducts, each having longitudinal chambers divided by internal walls, the at least two cable ducts meeting at a corner, the method comprising: inserting the cable guide into the cable ducting assembly at the corner, wherein the cable guide includes a wall portion having a convex side defining a minimum radius of curvature for a cable and wherein the cable guide is adapted to be received within the existing cable ducting assembly.

In other words, the cable guide is adapted to be installed without further modification of the existing cable ducting assembly. However, the existing cable ducting assembly may require disassembly of some parts and reassembly to enable insertion of the cable guide.

In the existing cable ducting assembly, the two cable ducts may meet at a mitred corner. In an alternative form of the invention, the existing cable ducting assembly may include a corner fitting with the two cable ducts meeting at the corner fitting.

Different forms of cable guides may be provided for an internal corner and an external corner. For an internal corner, the cable guide may have any of the features set forth in connection with the first aspect of the invention. This cable guide is versatile in that it can be used with either two chamber ducting or three chamber ducting. In two chamber ducting, one chamber is intended for use with electrical cabling, while the other chamber is intended for use with data cabling.

The wall portion may span the chamber intended for data cabling. The retaining flaps may be connected to the internal walls separating the two chambers.

004435715 6 The same form of cable guide may be used with three chamber ducting in which two chambers are intended for data cabling with the third chamber intended for electrical cabling. The wall portion spans the two data chambers with the one or more apertures in the wall portion accommodating the internal walls of the ducting. A gap provided below the wall portion of the cable guide also accommodates internal walls of the ducting. Therefore, the same cable guide may be used for either two chamber or three chamber ducting.

In an external corner, the cable guide may be of a different form. Preferably, for an external corner the cable guide comprises a wall portion having a convex side defining a predetermined minimum radius of curvature for a cable and planar side wall portions. In the case of three chamber ducting, two cable guides may be inserted into respective data chambers. In two chamber ducting, only one cable guide is required for the data chamber.

In accordance with a third aspect of the present invention, there is provided a cable ducting assembly comprising at least two cable ducts each having longitudinal chambers divided by one or more internal walls, the at least two cable ducts meeting at a corner; a cable guide having a top and a bottom and including a wall portion having a convex side defining a predetermined minimum radius of curvature for a cable; and one or more apertures or gaps disposed intermediate the top and the bottom to receive parts of the one or more internal walls of the ducting.

The cable guide discussed above may include any of the features set out in accordance with the first aspect of the invention. The cable ducting assembly may further include a corner fitting whereby the two cable ducts meet at the corner fitting. The corner fitting may include tongues for securement of the corner fitting to the internal walls of the cable ducts whereby the tongues maintain the separation between the chambers.

This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of said 004435715 7 parts, elements or features, and where specific integers are mentioned herein which have know equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

The invention consists in the foregoing and also envisages constructions of which the following gives examples.

Brief description of the drawings In order that the invention may be more clearly understood, some embodiments will now be described by way of example with reference to the drawings in which: Figure 1 is an exploded perspective view of a cable ducting assembly in accordance with a first preferred embodiment of the present invention; Figure 2a is a perspective view of a first cable guide in accordance with a preferred embodiment of the present invention; Figure 2b is a side view of a partly formed component of the cable guide of Figure 2a; Figure 2c is a side view of a partly formed component of the cable guide of Figure 2a; Figure 3a is a perspective view of a second cable guide for use in the cable ducting assembly of Figure 1; Figure 3b is a plan view of the second cable guide of Figure 3a; Figure 4 is a perspective view of a third cable guide for use in the cable ducting assembly of Figure 1; Figure 5 is a perspective view of a corner fitting for use in the cable ducting assembly of Figure 1; 004435715 8 Figure 6 is an exploded perspective view of a cable ducting assembly according to a second preferred embodiment of the present invention.

Preferred forms of the invention Figure 1 illustrates a cable ducting assembly 10 using three sections of cable ducting 12, 14, 16. The three sections 12, 14, 16 are of the type having three longitudinal chambers 18, 20, 22 separated by internal walls 24, 26. Each of the sections 12, 14, 16 are cut from a length of extruded ducting which may be aluminium. In its fully assembled form, each section of the ducting 12, 14, 16 has a front wall 28 which is co-terminus with the length of the associated section. Each front wall 28 is removable to access the longitudinal chambers 18, 20, 22 within the ducting. Longitudinal chambers 18 and 20 are intended for data cabling.

Longitudinal chamber 22 is intended for electrical cabling.

The cable ducting assembly 10 as shown in Figure 1 shows two ducting sections 12, 14 meeting at right angles to define an internal corner as would be typically found in a normal rectangular shaped room. Sections 12 and 14 meet at an internal corner fitting 30. Ducting sections 14 and 16 meet at an external corner, such as might be found around a pillar. An external corner fitting 30 is provided at the external corner. The external corner fitting 30 may be the same as the internal corner fitting However, it will be appreciated that the corner fittings 30 are optional and instead, the sections 12, 14, 16 may be mitred at their corners instead of being cut off normal as shown.

Where a ducting section terminates, a blank end 32 may be provided to cover what would otherwise be an exposed end of the section 16. The blank end 32 is provided with connecting tabs 34 to enable the blank end 32 to be secured to the internal walls 24, 26 by the means of fixing clips 36. The blank end 32 along with the corner fittings 30, may be die-cast.

004435715 9 The foregoing describes a cable ducting assembly which is known. The following describes how existing cable ducting assemblies may be retrofitted with cable guides 40, 42, 44 in order to upgrade the ducting assembly for use with category 6 cable. However, the invention is not limited to retrofitting and the cable ducting assembly 10 which meets category 6 standards may be installed from scratch. The invention is also not limited in its application to category 6 cabling and may be applied in any situation where it is desired to define a minimum radius of curvature for a cable. Cable guide 40 is installed in the internal corner as shown whereas cable guides 42 and 44 are installed in the external corner behind the corner fitting Figures 2 to 2c illustrate the first cable guide 40 in greater detail. The cable guide 40 includes a curved wall portion 48 having a top 50 and a lower edge 52.

The cable guide 40 further includes planar side wall portions 54, 56 which are arranged to extend at right angles to each other. Intermediate the top and lower edge 50, 52 is provided a slot 60 extending across the curved wall portion 48. The slot 60 terminates in the side wall portions 54 and 56.

Figure 2b illustrates a component of the cable guide 40 which defines the curved wall portion 48 and the side wall portions 54, 56. As can be seen, the sheet metal component illustrated in Figure 2b is bent along lines to define the transition between the curved wall portion 48 and the side wall portions 54, 56.

The curved wall portion 48 is curved as shown in Figure 2a to define the minimum allowable radius of curvature for category 6 cable.

Figure 2c illustrates a further component of the cable guide 40 of Figure 2a constructed from a piece of sheet metal. The sheet metal component is bent along its line of symmetry to form two lower walls 64 arranged at 900 to each other.

Further, retaining flaps 66 are obtained by folding portions at 900 to respective ones of the lower wall portions 64. The retaining flaps 66 thus extend at right angles to the curved wall portion 50. The component of Figure 2c once folded to the appropriate shape is secured to the lower ends of the side wall portions 54, 56 by spot welding as shown. The bottom of the cable guide is defined at 51.

004435715 To install the cable guide 40, the cable guide 40 is inserted into the internal corner of the ducting assembly 10 when the front walls 28 are not in position. The slot 60 accommodates parts of the internal wall 24 and additionally the corresponding tongue (optional) of the corner fitting 30. Further, any protruding edges of the internal wall 26 may be received underneath the lower edge 52 of the curved wall 48 and above the lower wall portions 64 where a gap 67 is provided.

Additionally, the side wall portions 54, 56 abut against the outer edges of the inner walls 24, 26. Retaining flaps 66 lie against the undersides of the internal walls 26 where they may be secured by fixing clips 36 as shown in Figure 1. Additionally, fixing clips may be secured through apertures 68 provided in the lower wall portions 64. The cable is passed around the convex side of the curved wall portion 48.

At the external corner, the second and third cable guides 42, 44 need be installed by sliding behind the corner fitting 30. The cable guides 42 and 44 are shown in greater detail in Figures 3a and 4. These cable guides 42, 44 are of different sizes to accommodate the different sized longitudinal chambers 18, Each of the cable guides 42, 44 comprises a curved wall portion 70 and two planar side wall portions 72 extending at 900 to each other. When installed, the cable is passed around the convex side of the curved wall portions 70 in order to ensure that the cable extends at the minimum allowable radius of curvature.

Figure 1 illustrates the form of the corner fitting 30. The corner fitting comprises upright sides 80, 82 arranged at right angles to each other with top and bottom end caps 84, 86 being provided. The corner fittings 30 are provided with a series of connecting tongues 88 to enable the corner fitting to be secured to the internal walls 24, 26 of the ducting by the use of fixing clips 36. Figure 5 shows an alternative form of corner fitting without some of the connecting tongues. Numerals and 87 point to internal detail.

Figure 6 illustrates an alternative cable ducting assembly 90 which is similar in many respects to the cable ducting assembly 10 illustrated in Figure 1 and like numerals are used to represent like parts. It will be appreciated that the cable ducting assembly 90 is constructed from ducting having only two internal 004435715 11 chambers with a single internal wall 92. The ducting has an upper longitudinal chamber 94 for data cabling and a lower longitudinal chamber 96 for electrical cabling. Figure 6 illustrates the versatility of the cable guide 40 in that it is also able to be used with the ducting shown having only two chambers 94, 96. In this embodiment, the whole of the curved wall portion 48 fits within the upper chamber 94. The internal wall 92 is positioned below the lower edge 52 of the curved wall portion 48, and above the end wall portion 64 within gap 67.

At the external corner, an alternative cable guide 98 is fitted. The height of the cable guide 98 is such as to span the width of the upper longitudinal chamber 94.

The foregoing describes only some embodiments of the present invention and modifications may be made thereto without departing from the scope of the present invention.

Claims (15)

1. A cable guide for cable ducting having longitudinal chambers divided by internal walls, the cable guide comprising: a top and a bottom; a wall portion having a convex side defining a predetermined minimum radius of curvature for a cable; one or more apertures or gaps disposed intermediate the top and the bottom to receive parts of the internal walls of the ducting.

2. The cable guide as claimed in claim 1 wherein the one or more apertures comprises a slot extending across the wall portion.

3. The cable guide as claimed in claim 1 or claim 2 further comprising planar side wall portions at each side edge of the wall portion.

4. The cable guide as claimed in any one of the preceding claims further comprising one or more retaining flaps extending substantially at right angles to the wall portion for attachment to the internal walls of the ducting. The cable guide as claimed in claim 4 wherein there are two retaining flaps of elongate form which extend in a direction at substantially right angles to each other.

6. The cable guide as claimed in claim 4 or claim 5 wherein the one or more retaining flaps are disposed adjacent a lower edge of the wall portion with a gap being provided between the lower edge of the wall portion and the one or more retaining flaps.

7. The cable guide as claimed in any one of the preceding claims wherein the wall portion is curved. 004435715 13

8. A method of installing a cable guide for an existing cable ducting assembly comprising at least two cable ducts, each having longitudinal chambers divided by internal walls, the at least two cable ducts meeting at a corner, the method comprising: inserting the cable guide into the cable ducting assembly at the corner, wherein the cable guide includes a wall portion having a convex side defining a minimum radius of curvature for a cable and wherein the cable guide is adapted to be received within the existing cable ducting assembly.

9. The method as claimed in claim 8 wherein the two cable ducts meet at a mitred corner. The method as claimed in claim 8 wherein the two cable ducts meet at a corner fitting.

11. The method as claimed in any one of claims 8 to 10 wherein the two cable ducts meet at an internal corner and the cable guide is as claimed in any one of claims to 1 to 7.

12. The method as claimed in any one of claims 8 to 10 wherein the two cable ducts meet at an external corner and the cable guide comprises a wall portion having a convex side defining a predetermined minimum radius of curvature for a cable and two planar side wall portions at each side edge of the wall portion.

13. A cable ducting assembly comprising at least two cable ducts each having longitudinal chambers divided by one or more internal walls, the at least two cable ducts meeting at a corner; a cable guide having a top and a bottom and including a wall portion having a convex side defining a predetermined minimum radius of curvature for a cable; and one or more apertures or gaps disposed intermediate the top and the bottom to receive parts of the one or more internal walls of the ducting.

14. The cable ducting assembly as claimed in claim 13 wherein the two cable ducts form a mitred corner. 004435715 14 The cable ducting assembly as claimed in claim 13 wherein the two cable ducts meet at a corner fitting.

16. A cable guide substantially as hereinbefore described with reference to the accompanying figures.

17. A method of installing a cable guide substantially as hereinbefore described with reference to the accompanying figures.

18. A cable ducting assembly substantially as hereinbefore described with reference to the accompanying figures. Moduline Pty Ltd By its Registered Patent Attorneys Freehills Carter Smith Beadle 17 February 2004