GB2482923A

GB2482923A - Cable trunking connection

Info

Publication number: GB2482923A
Application number: GB201016044A
Authority: GB
Inventors: Habib Rahman; Stephen Willmore
Original assignee: Legrand Electric Ltd
Current assignee: Legrand Electric Ltd
Priority date: 2010-08-16
Filing date: 2010-09-24
Publication date: 2012-02-22
Also published as: GB2484566A; IE20110360A1; IE86859B1; IE20130125A1; IE20100551A1; GB201016044D0; EG26484A; IE86777B1; GB2484566B; GB201113826D0; IE86217B1

Abstract

A cable trunking device, comprises first and second cable trunking components 2, and a coupling component 4. The first trunking component has an end portion for insertion into a first end portion of the coupling component, and the second trunking component has an end portion for insertion into a second end portion of the coupling component. The end portions of the first and second trunking components one or more guide channels 20 configured to receive and guide respective fastening components 10 supported on an external wall of said coupling component to respective fastening positions. At least one fastening component at said first end portion of the coupling component is associated with at least one respective fastening component at said second end portion of the coupling component via an internal bridge 14.

Description

CABLE TRUNKING DEVICE

The present invention relates to devices for routing one or more power and/or communication cables from one location to another.

Cable trunking devices generally come in easily transportable and manageable sections that can be assembled together on site.

Assembling cable trunking typically involves connecting generally U-shaped base sections each comprising a pair of side walls and a base wall.

According to one known technique, the generally U-shaped base sections are generally of the same width and are connected together with a short U-shaped connecting unit. The connecting unit has a greater width than that of the base sections such that the end portions of the connecting unit can be inserted into the end portions of respective base sections.

There has been identified the challenge of developing a new technique by which cable trunking sections can be assembled quickly and safely.

It is an aim of the present invention to meet this challenge.

The present invention provides a cable trunking device, comprising: first and second cable trunking components, and a coupling component, wherein the first trunking component has an end portion for insertion into a first end portion of the coupling component, and the second trunking component has an end portion for insertion into a second end portion of the coupling component; wherein said end portions of the first and second trunking components define in one or more walls thereof one or more guide channels configured to receive and guide respective fastening components supported on an external wall of said coupling component to respective fastening positions, at which the fastening components are usable to increase the force of contact between the trunking components and the coupling component, and wherein at least one fastening component at said first end portion of the coupling component is associated with at least one respective fastening component at said second end portion of the coupling component via an internal bridge.

In one embodiment, the fastening components are male screw-thread components, and the internal bridge defines holes with complementary female screw-threads at opposite ends of the internal bridge.

In one embodiment, each internal bridge comprises female screw-threaded components fixed to opposite ends of a support strip.

In one embodiment, each internal bridge is angled outwards in relation to the external wall of the coupling component about a line at a substantially central portion of the internal bridge.

In one embodiment, each internal bridge comprises one or more pointed projections directed towards an inner surface of the external wall of the coupling component.

In one embodiment, each internal bridge comprises at least one of said pointed projections on each side of said substantially central portion of the internal bridge.

In one embodiment, said end portion of each trunking component extends in a first direction to a first end thereof; and wherein the guide channels defined in said end portion extend from said first end, and wherein at said fastening position relative movement of the respective trunking component and coupling component in said first direction is blocked.

In one embodiment, said fastening components are detachable from the coupling component.

In one embodiment, the end portions of the trun king components each have two side walls joined by a base wall; each guide channel includes a proximal part extending from said first end substantially in the first direction and leading to a distal part extending substantially perpendicular to the first direction and away from the base wall; and wherein the height of the side walls of the end portions of the coupling component is less than the height of the side walls of the trunking components so as to enable sliding of the fastening components along the proximal and distal parts of the respective guide channels to guide the coupling component to said fastening position.

The present invention also provides a method of using a cable trunking device as described above, comprising inserting the end portions of one or more walls of the first trunking component into gaps between the internal bridges and external walls at the first end of the coupling component, and sliding the fastening components supported at said first end of the coupling component along the respective guide channels of the first trunking component to guide the first end of the coupling component to said fastening positions; and thereafter using the fastening components to secure the first end of the coupling component to the first truriking component.

In one embodiment, the method comprises inserting the end portions of one or more walls of the second trunking component into gaps defined between the internal bridges and external walls at the second end of the coupling component, and sliding the fastening components supported at said second end of the coupling component along the respective guide channels of the second trunking component to guide the second end of the coupling component to said fastening positions; and thereafter using the fastening components to secure the second end of the coupling component to the second trunking component.

Hereunder follows a detailed description of embodiments of the invention, by way of example only, with reference to the following drawings, in which:-Figure 1 illustrates the assembly of two trunking sections according to an embodiment of the present invention; Figure 2 illustrates in more detail one of the parts illustrated in Figure 1; and Figure 3 illustrates a bent and cut steel strip used in the manufacture of the part illustrated in Figure 2.

A cable trunking device according to a first embodiment of the present invention comprises: first and second cable trunking bodies 2 of identical shape and dimensions; a connecting unit 4; and fastening means 10. The first and second cable trunking bodies 2 and the connecting unit 4 each comprise a pair of opposing side walls connected via a respective base wall to form parts that have a substantially U-shaped external profile. The widths of the first and second cable trunking bodies 2 are selected such that their end portions closely fit inside the end portions of the connecting unit 4 without leaving a substantial gap between the external walls of the con necting unit 4 and the respective walls of the first and second cable trunking bodies 2.

The four sets of fastening means 10 provided at each end of the connecting unit 4 each comprise a bolt 10 inserted into a respective hole defined in the external side wall of the connecting unit 4, and having a diameter smaller than the diameter of the head 11 of the bolt 10. The distal ends 13 of the bolts are screwed into complementary female nutserts 15 provided as part of internal clamping plates 14, by which the bolts 10 are held on the external wall of the connecting unit 4. Each clamping plate 14 is provided with two nutserts 15, one for receiving a bolt 10 at one end portion of the connecting unit 4 and one for receiving a bolt 10 at the opposite end portion of the connecting unit. Pairs of corresponding bolts at opposite ends of the connecting unit 4 are associated with one another via the clamping plate 14.

The number of sets of fastening means 10 provided at each end of the connecting unit could be more or less than 4 depending on the height of the side walls of the trunking sections. For example, it may be possible with trunking sections of relatively small height to only have two sets of fastening means 10 at end of the connecting unit 4.

The clamping plate 14 is made from a strip of sheet steel 22 in which holes 23 are cut to receive respective bolts 10. The nutserts 15 secured to the strip of sheet steel 22 are aligned with these holes 23. A cutting/punching tool is used to force substantially triangular portions of the sheet steel strip out of the plane of the remainder of the strip to form sharp points 19 projecting from the surface 21 of the clamping plate 14 to face the inner surface of the external wall of the connecting unit (i.e. the clamping plate surface 21 opposite to that on which the nutserts 15 are located). In this example, the angle that the above-mentioned triangular portions make with respect to the plane of the steel strip is about 10 degrees.

Furthermore, the sheet steel strip is bent about a line located substantially centrally between the two nutserts secured to opposite ends of the clamping plate 14. In this example, the sheet steel strip is bent by about 3 degrees; the two halves of the surface 21 of the clamping plate 14 to face the inner surface of the external wall of the connecting unit (i.e. the clamping plate surface 21 opposite to that on which the nutserts are located) define a reflex angle of about 183 degrees.

In order to resist the accidental removal of a bolt 10 from the respective nutsert 15 and the bolt 10 becoming detached from the cable trunking body 2, the bolts 10 can include a nylon insert or can include a slight deformation on a portion of the screw thread at the distal end 1 3 of the bolt 10. This has the advantage, for example, that it reduces the risk of the bolt 10 becoming accidentally separated from the connecting unit 4 during transportation to the assembly site. Slots 20 are defined in the side walls at both end portions of the first and second cable trunking bodies 2.

The slots 20 extend from the end of the cable trunking bodies 2 and are configured to receive the bolts 10 provided on the connecting unit 4. Each slot 20 is substantially L-shaped and comprises a relatively long first straight section extending substantially parallel to the base wall of the cable trunking section, and a relatively short second straight section extending substantially perpendicular to the first straight section and away from the base wall. At the time of assembly, the connecting unit 4 and one of the trunking bodies 2 are connected together by sliding a portion of the bolts 10 between the external wall of the connecting unit 4 and the clamping plate 14 along respective L-shaped slots 20 to the end of the slots 20.

When the base walls of the connecting unit 4 and the trunking body 2 are at the same level, the entrance of the slots 20 is at a lower level than the respective corresponding bolt 10 supported on the connecting unit 4. In order to slide the bolts along the slots 20, the connecting unit 4 is first lowered relative to the trunking body 2 (assuming that the trunking body 2 and the connecting unit 4 are oriented with their base walls downwards). When the bolts 10 reach the end of the first straight section of the slots 20, the connecting unit 4 is raised relative to the trunking body 2 until the base wall of the trunking body 2 lies against the base wall of the connecting unit, and the bolts 10 sit at the top of the second straight section.

With the bolts 10 located at the end of the L-shaped slots 20, the part of the side wall that defines the second straight section of a slot blocks the respective bolt 10 from moving in a direction parallel to the base walls of the connecting unit and cable trunking body 2. In this configuration, the bolts 10 are forcibly turned further into the respective nutserts 15 to increase the force of contact between the side walls of the trunking body and the clamping plates 14 and external walls and of the connecting unit 4. The heads 11 of the bolts 10 are adapted so that the bolts 10 may be turned and tightened by all of a hex head socket, a cross-head screwdriver and a flat blade screwdriver. The heads 11 are also provided with serrations on the underside of the head, for a better earthing continuity between the connecting unit 4 and the trunking bodies 2. The head is flanged and the serrations are provided on the underside of the flange. For example, the hex head socket is an M5 hex head socket and the cross-head screwdriver is a Pozi No. 2.

The action of forcibly turning the bolts 10 into the respective nutserts 15 presses the clamping plates 14 against the inner surface of the side walls of the trunking body.

The sharp points 19 of the clamping plate 14 are designed to, at this time, cut through any paint or other non-metallic surface deposits on the inner surface of the side wall of the trunking body 2, and thereby create a reliable conductive, earthing connection between the clamping plate and the trunking body.

As mentioned, the clamping plate 14 is bent about a line located substantially centrally between the two nutserts 15 provided on the clamping plate 14. The action of tightly forcing one half of each clamping plate 14 against the inner surface of the side wall of the trunking body 2 leaves the other half of the clamping plate 14 in a diverging configuration in relation to the inner surface of the external wall of the connecting unit 4. This diverging configuration facilitates the assembly of the second trunking body 2 and the connecting unit 4 by making it easier to locate the side walls of the second trunking body in the gaps between the clamping plates 14 and the inner surfaces of the external wall of the connecting unit 4. The second trunking body and connecting unit 4 are assembled in the same way as the first trunking body 2 and the connecting unit 4.

The connecting unit 4 is designed such that the ends of the two cable trunking bodies 2 substantially meet at a central location within the connecting unit 4.

In some situations it may be necessary to connect the connecting unit 4 to a cable trunking section without an L-shaped slot. For example, the fitter may need to cut off the end portion of a cable trunking body 2 including the above-described L-shaped slot in order to reduce the trunking body from a standard manufactured length to a customised length. The connection can then be achieved by the following steps: (i) creating on-site through-holes in the end portions of the cut-to-length cable trunking body; (ii) removing the bolts 10 from the respective end of the connecting unit 4; and (iii) sliding the cut end portion of cut-to-length cable trunking body 2 into the connecting unit 4 such that the through holes of the connecting unit 4 align with said through holes cut into the side walls of the cut-to-length cable trunking body 2: and (iv) then using the bolts 10 and clamping plates 14 with nutserts 15 to secure the connecting unit 4 and cable trunking body 2 together.

A good conductive, earthing connection between each half of the clamping plates and the inner surfaces of the trunking bodies can provide a better conductive, earth ing connection between the two trunking bodies 2.

After the cable trunking bodies 2 are connected together and cable is installed therein, the cable trunking bodies are generally closed off using lids 6. The lids can be reversibly fitted to the cable trunking bodies 2 using clip-locking devices 8 of the kind described in UK patent application no. 1013839.4, the entire content of which is incorporated herein by reference.

The location of the external walls of the connecting unit on the outside of the end portions of the trunking bodies makes it easier to visually confirm that each pair of adjacent trunking bodies in a series of trunking body sections are joined by a connecting unit.

The technique described above facilitates the quick-fitting of cable trunking bodies together and thereby reduces the installation time for the contractor. To further reduce the installation time, the connecting unit 4 could be pre-assembled to one end of a cable trunking body 2 during manufacture, so that the only operation required on site to join two cable trunking bodies 2 would be to couple one end of the connecting unit 4 already assembled to one cable trunking body to another cable trunking body.

The lids 6 mentioned above could be supplied detached from the trunking bodies.

The clip-locking devices mentioned above enable the lids 6 to be push fit by hand on to the trunking bodies without requiring the use of a screwdriver to rotate turnbuckles or screws as is common practice with some conventional trunking systems. The use of such clip-locking devices can further reduce the assembly time on site for the contractor.

All of the above-described components are made out of steel.

The applicant draws attention to the fact that the present invention may inôlude any feature or combination of features disclosed herein either implicitly or explicitly or any generalisation thereof, without limitation to the scope of any definitions set out above. In view of the foregoing description it will be evident to a person skilled in the art that various modifications may be made to the above-described embodiments within the scope of the invention.

Claims

CLAIMS1. A cable trunking device, comprising: first and second cable trunking components, and a coupling component, wherein the first trunking component has an end portion for insertion into a first end portion of the coupling component, and the second trunking component has an end portion for insertion into a second end portion of the coupling component; wherein said end portions of the first and second trunking components define in one or more walls thereof one or more guide channels configured to receive and guide respective fastening components supported on an external wall of said coupling component to respective fastening positions, at which the fastening components are usable to increase the force of contact between the trunking components and the coupling component, and wherein at least one fastening component at said first end portion of the coupling component is associated with at least one respective fastening component at said second end portion of the coupling component via an internal bridge.
2. A device according to claim 1, wherein the fastening components are male screw-thread components, and the internal bridge defines holes with complementary female screw-threads at opposite ends of the internal bridge.
3. A device according to claim 2, wherein each internal bridge comprises female screw-threaded components fixed to opposite ends of a support strip.
4. A device according to any of claims I to 3, wherein each internal bridge is angled outwards in relation to the external wall of the coupling component about a line at a substantially central portion of the internal bridge.
5. A device according to any of claims I to 4, wherein each internal bridge comprises one or more pointed projections directed towards an inner surface of the external wall of the coupling component.
6. A device according to claim 5 as dependent on claim 4, wherein each internal bridge comprises at least one of said pointed projections on each side of said substantially central portion of the internal bridge.
7. A device according to any preceding claim, wherein said end portion of each trunking component extends in a first direction to a first end thereof; and wherein the guide channels defined in said end portion extend from said first end, and wherein at said fastening position relative movement of the respective trunking component and coupling component in said first direction is blocked.
8. A device according to any preceding claim, wherein said fastening components are detachable from the coupling component.
9. A device according to claim 7, wherein the end portions of the trun king components each have two side walls joined by a base wall; each guide channel includes a proximal part extending from said first end substantially in the first direction and leading to a distal part extending substantially perpendicular to the first direction and away from the base wall; and wherein the height of the side walls of the end portions of the coupling component is less than the height of the side walls of the trunking components so as to enable sliding of the fastening components along the proximal and distal parts of the respective guide channels to guide the coupling component to said fastening position.
10. A method of using a cable trunking device according to any preceding claim, comprising inserting the end portions of one or more walls of the first trunking component into gaps between the internal bridges and external walls at the first end of the coupling component, and sliding the fastening components supported at said first end of the coupling component along the respective guide channels of the first trunking component to guide the first end of the coupling component to said fastening positions; and thereafter using the fastening components to secure the first end of the coupling component to the first trunking component.
11. A method according to claim 10, further comprising: inserting the end portions of one or more walls of the second trunking component into gaps defined between the internal bridges and external walls at the second end of the coupling component, and sliding the fastening components supported at said second end of the coupling component along the respective guide channels of the second trunking component to guide the second end of the coupling component to said fastening positions; and thereafter using the fastening components to secure the second end of the coupling component to the second trunking component.
12. A device as substantially hereinbefore described with reference to Figures 1, 2 and 3 of the accompany drawings.
13. A method as substantially hereinbefore described with reference to Figures 1, 2 and 3 of the accompany drawings.