GB2407439A

GB2407439A - A protection device for cable assemblies

Info

Publication number: GB2407439A
Application number: GB0324766A
Authority: GB
Inventors: Dave Brown
Original assignee: SIEGRIST OREL Ltd
Current assignee: SIEGRIST OREL Ltd
Priority date: 2003-10-23
Filing date: 2003-10-23
Publication date: 2005-04-27
Anticipated expiration: 2023-10-23
Also published as: GB2407439B; GB0324766D0

Abstract

A device 20 providing a protective sleeve around a bundle 14 of one or more cables, preferably bridging gaps between raceway sections 10, 12, comprises a substantially flat, bendable web portion 22, having at least one opening 24 adjacent one edge and a guide 26, slidable though the at least one opening 24, projecting from the opposite edge. An arrangement 28 for locking the guide though the opening is provided, preferably comprising lateral tabs on each side of the guide, each having tapered leading surfaces and abrupt trailing surfaces, thereby they are only able to pass though the opening 24 in one direction. The device is preferably formed from a single component, and is formed from PTFE. Alternatively, the web 22 and guide 26 may be separate components joined together, the web 22 being formed from FEP. The device also prescribes a method of its installation. A second invention claims a protection device having an integral component comprising a plurality of enclosure channels.

Description

CABLE ASSEMBLIES AND PROTECTION DEVICES FOR THE CABLES

This invention relates to cable assemblies, and particularly to protection devices for protecting the cables at the gaps between raceways which define cable paths around an installation.

Cable raceways are used to position and protect bundles of cables which pass around an installation, such as a building or vessel such as an aircraft or boat. In some applications, some relative movement between different sections of the raceway is required to allow for some movement. For example, cable raceways which extend along the inside of aircraft wings need to take account of the movement of the aircraft wings in normal use.

To allow for this movement, the raceways or other conduits are typically assembled as a number of sections, and a small gap is provided between the ends of aligned raceway sections. The cable bundles housed in channels of the raceway sections typically span the gap between the ends of the raceway sections.

One problem associated with this type of installation is that chafing of the protective insulation around the cables can arise over a prolonged period as a result of the relative movement between the raceway sections. When the installation has a length of service of many years, for example an aircraft, the situation can arise that the cables become damaged before the end of the normal service life of the installation.

Repairing cables is an extremely expensive operation, particularly as joins between cables may not be permitted so that complete reinstallation of the wiring may be required. There is therefore a need to prevent this type of cable damage in existing cable assemblies.

A further problem associated with the gap between ends of raceway sections concerns electromagnetic shielding. In certain applications, such as military aircraft applications, the cable raceways are designed to provide a high degree of electromagnetic shielding to eliminate the risk of errors in the control signals carried by the cables. The gap between raceway sections does not afford the same degree of electromagnetic shielding. In these applications there is therefore a need both to prevent chafing of cables spanning the gap between ends of raceway sections and to provide electromagnetic shielding in these parts of the cable assembly.

According to one aspect of the invention, there is provided a protection device for cable assemblies for providing a protective sleeve around a bundle of one or more cables, comprising: a substantially flat, bendable, web portion, having at least one opening adjacent 5one edge and a guide projecting from an opposite edge, wherein the guide is slidable through one of the at least one openings, thereby to roll the web portion Into a sleeve, and wherein a locking arrangement is provided for locking the guide through the opening.

This device defines an open flat component initially, which can thus be fed 10around an existing cable bundle. This enables the device to be retro- fitted to an existing cable assembly, for example to provide protection against chafing at the junction between raceways. The device can, for example, be retro-fitted to aircraft wiring assemblies in order to prolong the life span.

The device is preferably a single integral component, which reduces production 15costs. For example, it may be made from a flat sheet, for example of PTFE. It may be stamped from such a sheet. Alternatively, it may be injection moulded, again for

example from PTFE.

Instead, the web and the guide can be separate components which are joined together. The web can be made of FEP (a modified PTFE), for example laser cut from 20an FEP sheet. There are of course many other materials which can be used.

The locking arrangement preferably comprises lateral tabs on each side of the guide, which are adapted to pass through the opening in one direction only. This allows the device to be fitted with an easy pull action, and the device then stays in place.

25The invention also provides a wiring installation comprising a plurality of cable raceway devices, adjacent raceway devices being separated by a gap between their ends, a plurality of bundles of cables, each cable bundle being housed in a raceway channel, wherein a bundle of cables spanning adjacent raceway devices bridges the gap; and one or more of the devices of the Invention, each provided around a respective 30bundle of cables at the location where the bundle bridges the gap.

This wiring installation has thus been serviced using the devices of the invention, particularly to prevent future chafing of the cables where they span the gaps between end-to-end raceway sections.

The invention also provides a method of installing a protection device for a cable assembly for providing a protective sleeve around a bundle of one or more cables, the method comprising: locating a gap between ends of an adjacent pair of cable raceway devices; providing a protection device having a substantially flat, bendable, web portion, having at least one opening adjacent one edge and a guide projecting from an opposite edge; sliding the guide around a bundle of cables which spans the gap and passing the guide through one of the at least one openings, thereby to roll the web portion into a sleeve; and locking the guide through the opening.

This provides the retrofit installation method for the device of the invention.

According to a second aspect of the invention, there is provided a protection device for cable assemblies for providing a protective enclosure for a plurality of 1 S bundles of one or more cables, comprising: an integral component having a plurality of channel enclosures running side by side in parallel, each channel enclosure having an upper face with a slot running the length of the channel enclosure, each channel enclosure further comprising a pair of side walls and a base wall, wherein the adjacent side walls and base walls of adjacent channels are separated by a spacing and adjacent channel enclosures are connected together by the upper faces.

This device allows the gap between raceway ends to be bridged whilst providing enclosures for each cable bundle. In addition, the enclosures provide electromagnetic shielding where the cable bundles bridge this gap, and where the electromagnetic shielding provided by the raceways is not effective.

The device preferably further comprises two outermost side walls, separated by a spacing from the outermost side walls of the outermost channel enclosures, the outermost side walls being connected to the outermost channel enclosures by the upper faces.

The device may be made from carbon loaded silicone. This combines the required flexibility between raceways and provides the desired electromagnetic shielding.

The ends of the device are preferably adapted to slide over a raceway device having a number of raceways each for carrying a bundle of cables, the number of raceways corresponding to the number of channel enclosures.

Examples of the Invention will now be described in detail with reference to the accompanying drawings in which: Figure I shows a cable assembly in which protection devices of the invention have been installed; Figure 2 shows in more detail one of the protection devices used in the assembly of Figure 1; Figure 3 shows a second example of protection device; Figure 4 shows a third example of protection device; Figure 5 shows a second type of protection device of the invention; Figure 6 shows the device of Figure 5 in greater detail; and Figure 7 shows in more detail how the device of Figures 5 and 6 is coupled to existing raceway sections.

Figure 1 shows a part of a cable assembly in which raceways 0, 12 are used to locate and protect bundles 14 of cables. For example, these raceway sections may run the length of aircraft wings to provide electrical control signals. The gap 16 between raceway sections 10, 12 is provided to allow some relative movement, which is required as a result of flexing of the aircraft wing. There are, of course, other applications in which raceway sections are used to carry bundles of cables and in which gaps 16 are required to allow for some relative movement.

There are many installations of this type existing in fleets of aircraft. When these were installed, the cable bundles 14 were allowed simply to span the gaps 16, as this provided no risk of the cable bundles 14 escaping from the channels defined by the raceway sections 10, 12.

This has, however, proven to be a problem in that chafing of the individual cables occurs in the region of the gaps 16 as a result of the relative movement.

Figure 1 shows two cable bundles 14 in which a protection device 20 of the invention has been retrofitted. As shown, each protection device 20 provides a protective sleeve around the bundle 14 of cables. The protection device has a flat bendable web portion 22. At one edge of the web there is at least one opening 24, and a guide 26 extends from the opposite edge.

The guide 26 is passed around the bundle of cables 14, and has sufficient rigidity, and is also sufficiently bendable, to make this easy. Thus, the guide 26 is passed around the bundle of cables 14 in order to roll up the web portion 22 into a sleeve, as shown for the front protection device 20 in Figure 1. The guide 26 is then passed through the opening 24, and a locking arrangement 28 locks the web 22 into the rolled up sleeve configuration, as shown for the protection device 20 at the back of Figure 1. Once installed, the excess length of the guide 26 can be cut off, as shown.

The locking arrangement 28 comprises a wedge with two opposite tapered faces which push through the opening 24, which has a slot shape. Once the webs have passed through the slot, the back of the locking arrangement 28 prevents the unrolling of the sleeve. Thus, the width of the locking arrangement is greater than the width of the slot 24.

The material of the protection device is sufficiently flexible to allow easy installation, and is sufficiently resistant to wear that it will last the expected life of the installation in which the cable assembly is installed. This resistance to wear can be achieved by having a low friction material, such as PTFE.

Two slots 24 are shown for each protection device in Figure 1, and this enables the device 20 to be rolled up tightly around cable bundles 14 having different numbers of cables.

The protection device 20 used in Figure 1 is shown in greater detail in Figure 2.

As mentioned above, one preferred material is PTFE.

In one example, the web 22 and the guide 26 can be different components. For example, the web 22 can be formed from a thin sheet of PTFE, for example 0.3-0.6mm thick, for example 0.4mm thick. To provide the guide 26 with the required rigidity and bendability, this may be formed from a thicker PTFE, for example cylindrical having a diameter of 1.5mm. This can then be heat welded to the web 22.

One preferred method of manufacturing the device of Figure 2 is to laser cut the web 22 from a PTFE sheet, and to extrude or mould the cylindrical guide 26. These components may be made from PTFE, or FEP (a modified PTFE) .

As shown in Figure 2, the slots 24 are designed to receive the guide 26, and have a central opening 30 for receiving the guide 26, and thinner extensions 32 which receive the tabs of the locking arrangement 28. The locking arrangement 28 is formed as part of the web 22.

Typical dimensions of the web 22 give a length "1" of the sleeve of 3070mm.

The distance between the openings 24 and the locking arrangement 28 is approximately the same.

Figure 3 shows a second example of protection device 20 which is formed as a single integral component.

The device of Figure 3 is intended to be injection moulded from PTFE. The guide 26 again has a circular cross section, with a diameter of approximately 1.5mm, and the thickness of the web 22 may be approximately 0.5mm. The device functions in exactly the same way as that of Figure 2.

The example of Figure 4 is intended to be formed from a sheet of material, for example PTFE or PEP. In this case, the guide 26 has the same thickness as the web 22, for example 0.5mm. In order to provide the guide 26 with sufficient rigidity to facilitate passing the guide around a bundle of cables, it is substantially wider, for example approximately lOmm wide. This version can be stamped or laser cut from a sheet, which reduces the manufacturing cost. The hole 34 shown in Figures 3 and 4 is used to tie together a bundle of the devices after they are installed.

A second device 40 of the invention is shown in Figure 5, again bridging the gap between ends of raceway sections 10, 12. This device is for installation when the raceway sections 10, 12 are themselves installed, and is therefore not a retro-fit device.

The device 40 again comprises an integral component and which defines a number of channel enclosures 42 for the cable bundles. Each enclosure has a base wall 44, a pair of side walls 46 and an upper face 48. Each channel enclosure 42 has a slot 50 running the length of the channel enclosure. This enables the cables to be inserted through the slot 50, one by one or in bunches.

As shown more clearly in Figure 6, adjacent channel enclosures 42 are separated by a gap 52, and as will be apparent from the following, this gap 52 is designed to receive the walls of the raceway sections 10, 12. The device 40 thus comprises a number of parallel channel enclosures which are essentially separate housings, but which are joined together by the upper face 48. In addition, two outermost side walls 54 are provided, again connected by the upper face 48.

The material of the device 40 provides sufficient flexibility to allow relative movement between the raceway sections 10, 12, and is also formed from a material which provides electromagnetic shielding. The preferred material is carbon loaded silicon.

In order to install the device 40, it is slid over the ends of two adjacent raceway sections when these are being installed. The device 40 may have a kink, as shown in Figure 5, so that it follows the path of the raceway sections.

Figure 6 shows the device 40 from above (on the left) in cross section (in the middle) and from below (on the right).

Figure 7 shows the device 40 installed around the end of a raceway section 10, which Is shown solid.

The underside of the raceway section 10 (the left in Figure 7) is attached to the structure, typically using an "H" cross section member, and this gives sufficient space for the overhang of the outermost side walls 54 shown in Figure 7.

The raceway sections themselves are typically aluminium, although other materials may be used in applications where greater electromagnetic shielding is required. The raceway sections may, for example, be formed from a carbon composite.

A number of possible materials have been described for the device of the invention, but there are many more which will be apparent to those skilled in the art.

For example another possible material is a fibreglass cloth Impregnated with PTFE.

The invention has been described in particular in connection with use in the wiring installation of an aircraft. As mentioned above, the invention can be used for any installation where gaps need to be left between guide channels which house cable bundles. Whenever these gaps are required to allow for relative movement, there is a risk of chafing of the cables carried in the guide channels, and the invention can then be employed to protect cables at the location of these gaps.

A small number of specific examples of shape for the protection device has been described, but it will be apparent to those skilled in the art that there are many variations which can be employed.

Various other modifications will be apparent to those skilled in the art.

Claims

1. A protection device for cable assemblies for providing a protective sleeve around a bundle of one or more cables, comprising: a substantially flat, bendable, web portion, having at least one opening adjacent one edge and a guide projecting from an opposite edge, wherein the guide is slidable through one of the at least one openings, thereby to roll the web portion into a sleeve, and wherein a locking arrangement is provided for locking the guide through the opening.

2. A device as claimed in claim 1, comprising a single integral component.

3. A device as claimed in claim 2, wherein the single integral component comprises a substantially flat sheet.

4. A device as claimed in claim 2 or 3 made of PTFE.

5. A device as claimed in claim 4, which is stamped from a PTFE sheet.

6. A device as claimed in claim 4, which is injection moulded from PTFE.

7. A device as claimed in claim 1, wherein the web and the guide are separate components which are joined together.

8. A device as claimed in claim 7, wherein the web is made of PEP.

9. A device as claimed in claim 8, wherein the web is laser cut from an FEP sheet.

10. A device as claimed in any preceding claim, wherein the locking arrangement comprises lateral tabs on each side of the guide, which are adapted to pass through the opening in one direction only.

11. A device as claimed in claim 10, wherein the tabs comprise tapered leading surfaces for insertion through the opening, and abrupt trailing surfaces.

12. A wiring installation comprising: a plurality of cable raceway devices, adjacent raceway devices being separated by a gap between their ends; a plurality of bundles of cables, each cable bundle being housed in a raceway channel, wherein a bundle of cables spanning adjacent raceway devices bridges the gap; and one or more devices as claimed in any preceding claim, each provided around a respective bundle of cables at the location where the bundle bridges the gap.

13. A method of installing a protection device for a cable assembly for providing a protective sleeve around a bundle of one or more cables, the method comprising: locating a gap between ends of an adjacent pair of cable raceway devices; providing a protection device having a substantially flat, bendable, web portion, having at least one opening adjacent one edge and a guide projecting from an opposite edge; sliding the guide around a bundle of cables which spans the gap and passing the guide through one of the at least one openings, thereby to roll the web portion into a sleeve; and locking the guide through the opening.

14. A protection device for cable assemblies for providing a protective enclosure for a plurality of bundles of one or more cables, comprising: an integral component having a plurality of channel enclosures running side by side in parallel, each channel enclosure having an upper face with a slot running the length of the channel enclosure, each channel enclosure further comprising a pair of side walls and a base wall, wherein the adjacent side walls and base walls of adjacent channels are separated by a spacing and adjacent channel enclosures are connected together by the upper faces.

13. A device as claimed in claim 12, further comprising two outermost side walls, separated by a spacing from the outermost side walls of the outermost channel enclosures, the outermost side walls being connected to the outermost channel enclosures by the upper faces.

14. A device as claimed in claim l 2 or 13, made from carbon loaded silicone.

15. A device as claimed in claim 12, 13 or 14, wherein the ends of the device are adapted to slide over a raceway device having a number of raceways each for carrying a bundle of cables, the number of raceways corresponding to the number of channel enclosures.