WO2002035670A1

WO2002035670A1 - Cable retainer

Info

Publication number: WO2002035670A1
Application number: PCT/GB2001/004727
Authority: WO
Inventors: Rupert Jonathan Symons; Richard Brown
Original assignee: Sybre Limited
Priority date: 2000-10-24
Filing date: 2001-10-24
Publication date: 2002-05-02
Also published as: GB0311927D0; GB2384818A; AU2002212439A1; GB0026058D0

Abstract

A clip for the retention of electrical cables within an electrical trunking (16) having first and second inner walls (7, 8) and a removable lid section. The clip comprises a first engaging portion (1) for engaging a first inner trunking wall, a second engaging portion (2) for engaging a second trunking inner wall, said first and second engaging portions being joined by a resiliently flexible member (3).

Description

CABLE RETAINER

The present invention relates to electrical installation trunking, and specifically to a clip for retaining electrical cables therein.

Λt present, many installations of electrical wiring in industrial and commercial buildings are conducted using a cable trunking system. This usually comprises a main trunking that is arranged to run from a main incoming electrical supply, around the walls of the building, to electrical outlets or supply points required in the building. The electrical outlets or supply points are usually linked to the main trunking with smaller trunking, or quite often lengths of conduit.

The main trunking is usually comprised of two parts, a U sectioned channel that is affixed to the wall, and a shallow U sectioned lid that is removably attached to the channel. Electrical supply cables which are required to run from the main incoming supply to the electrical outlets or supply points are arranged to run inside the trunking channel, and are retained in place by the trunking lid which is fitted to the trunking channel.

As it is preferable to prevent any damage being sustained to the trunking due to the fact that it carries electrical cables, it is usually installed at a distance from a floor level so as to minimise any contact. This usually means that to install or access the trunking, suitable access equipment, such as ladders or staging, are required. When the trunking is installed, it can often be part of a complete electrical installation. This is usually done at the time ofthe building being built, or when being refurbished. This allows easy access for the fixing of the trunking and the running of the electrical supply cables. As this is usually performed by a number of people, few problems are found during the actual installation.

However, when the installation is required to be performed by a single person, or when later alterations are required to the electrical supply cables, when the building is in use, it can often prove to be a significant problem to get new electrical cables into the trunking, or to retain the existing cables within the trunking prior to and while the lids are refitted. It can be a frequent occurrence where the cable has a tendency to sag from the trunking preventing the lids being fitted. This problem is exacerbated by the fact that the trunking may have continuous lengths running many metres, and the trunking and lids are usually supplied in 3 or more metre lengths.

It is to this problem that the present invention is directed.

According to one aspect of the invention there is provided a clip for the retention of electrical cables within an electrical trunking having a removable lid section, comprising a first engaging portion, a second engaging portion, said first and second engaging portions being joined by a resiliently flexible member.

According to a second aspect of the invention there comprises a clip for the retention of electrical cables within an electrical trunking having first and second inner walls and a removable lid section, which clip comprises a first engaging portion for engaging a first inner trunking wall, a second engaging portion for engaging a second trunking inner wall, said first and second engaging portions being joined by a resiliently flexible member.

Optionally, the first and/or second engaging portions further comprises stabilising means to be placed in abutment with the respective first and/or second inner walls to prevent lateral movement or twisting of the clip. Preferably, the stabilising means is provided by a surface of the engaging portion(s abutting the first and/or second inner walls.

According to an optional feature of the first or second aspects of the invention, the resiliently flexible member is formed as a curved member.

According to another optional feature of the first or second aspects of the invention, the resilient!) flexible member is formed from a substantially laminar strip of resiliently flexible material. Optionally, the retaining clip is arranged such that the first and second engaging portions are in a planar relationship in its free position. In one class of embodiments, the first engaging portion is formed from a first panel and the second engaging portion is formed from a second panel, the first and second panels are hingedly interconnected by the resiliently flexible member. Optionally, the flexible member is connected to a central portion of the first and second panels and is separated at least in part along its side edges from the first and second panels by opposed slits.

According to an optional feature of either aspect of the invention, the flexible member further comprises one or more ribs to impart improved rigidity to the flexible member.

Alternatively, the first and second engaging portions are formed as laterally extending members at the opposing ends of the resiliently flexible member. The laterally extending members may be cylindrical in cross section.

In an alternative form, the first and second engaging portions are also formed from substantially laminar resiliently flexible material. Optionally, the first and second engaging portions are formed as returns at the opposing ends of the resiliently flexible member.

According to an optional feature of either aspect of the invention, stops are provided to prevent the withdrawal of the clip from the trunking are provided on the resilienth flexible member.

In another alternative form, the clip is formed from a rod material. Preferably, the surface of the rod material has a ribbed finish.

According to another optional feature of either aspect of the invention, finger recesses may be formed at the junctions of the first and second engaging portions, and the resiliently flexible member. 1 he curve of the resiliently flexible member may be convex in the direction of the linger recesses.

According to a further optional feature of this aspect of the invention, the first and second engaging portions are integrally formed with the resilienth flexible member. Optionally, the first and second engaging portions are co-moulded to the resiliently fiexible member.

The first and second engaging portions and/or the resiliently fiexible member may be formed from an injection moulded plastics material. Alternatively, the said resiliently flexible member is formed from a strip of spring steel.

The first and second engaging portions may have projecting pins, said resiliently flexible member has holes at opposing ends thereof, said first and second engaging portions being located on said resiliently flexible member by means of said pins and holes.

A third aspect of the invention provides a method of retaining cables within trunking having first and second inner walls and a removable lid section, by a clip described above, which method comprises the steps:

(0 placing one or more cables within the trunking;

(ii^") sliding the first engaging portion of the clip under the wires to be engaged with the lower inner wall; (iii) bending the flexible member and inserting the second engaging portion in the trunking so that it engages the upper inner wall; and

(iv) re-fitting the removable lid to the trunking.

Exemplary embodiments of the invention will now be described, by way of example only, with reference to the following drawings, in which:

FIGURE 1 is a plan \ iew of a first embodiment of clip according to the invention;

FIGURE 2 is a side elevation of the embodiment shown in Figure 1 :

FIGURES 3 and 4 show the first embodiment of the invention in place in electrical trunking:

FIGURE 5 is a perspective view of a second embodiment of clip; F IGURE 6 is a view of a portion of the clip shown in Figure 5:

FIGURE 7 is a perspectiv e v iew of a third embodiment of clip: FIGURES 8 and 9 show the third embodiment in cross-section positioned in the electrical trunking;

FIGURE 10 is a perspective view of a fourth embodiment of clip;

FIGURE 1 1 show the fourth embodiment in cross section positioned in electrical trunking; FIGURE 12 is a perspective view of a fifth embodiment of clip;

FIGURE 13 show the fifth embodiment in cross section positioned in electrical trunking;

FIGURES 14 and 15 are perspective view of a sixth embodiment showing a two-part clip;

FIGURE 16 show the sixth embodiment in cross section positioned in electrical trunking;

FIGURE 17 shows a seventh embodiment of clip; FIGURES 18, 19 and 20 are top plan, side and end elevations of an eighth embodiment of the invention;

FIGURE 21 is a perspective view of the eighth embodiment;

FIGURE 22 is a top plan view of a ninth embodiment of the invention;

FIGURES 23, 24, 25 and 26 are bottom plan, side and end elevations of the ninth embodiment; and

FIGURE 27 is a perspective view of the ninth embodiment.

Referring to the drawings and in particular Figures 1 to 3 there is shown a first embodiment of the invention in which there is a clip comprising a first engaging portion 1 , a second engaging portion 2, and a resiliently flexible member 3 joining the first and second engaging portions 1 , 2. The retaining clip C is shown in use fitted into a section of trunking 6, in Figure 3.

1 he trunking 6, as is well known, comprises an upper wall 7, a lower wall 8. front lips to the upper and lower walls 9 and 10, and a rear-mounting wall I 1. The trunking further comprises a removable lid section (not shown), which is affixed to the trunking usually by a plate that is piv oted to engage the front lips 9 and 10 thereby to retain the lid section. ^'I he retaining clip C is arranged such that the first engaging portion 1 abuts the inner face of the upper wall 7 of the trunking, and the second engaging portion 2 abuts the inner face of the lower wall 8 of the trunking. fhe resiliently flexible member 3 keeps the first and second engaging portions 1. 2 in an abutting relationship ith the inner faces of the upper and lower walls 7. 8. In this embodiment it is preferred that the retaining clip is foimed as a single piece, preferably from an injection moulded resiliently flexible plastics material, for example polypropylene or polyethylene. In some embodiments, the polypropylene is V I or V0 rated to comply with fire retardant requirements.

Also, in this embodiment, the retaining clip can be arranged such that the first and second engaging portions 1 , 2 are arranged in a co-planar relationship, linked by the resiliently flexible member 3. One or more finger recesses 4 and 5 may be formed in the clip, which in this embodiment, are at the junctions of the first and second engaging portions 1 and 2, and the resiliently flexible member 3.

In the embodiment shown in Figures 1 and 2 the resiliently flexible member is formed as a curved member. Preferablv , the curve is convex in the direction of the finger recesses 4 and 5 as shown in Figure 2 so as to improve the resilience.

In order to fit the retaining clip into the trunking, as shown in Figures 3 and 4, the first and second engaging portions are forced into an opposed orientation as shown by arrows 14 and 15 by a user U (Figure 4). This results in the resiliently flexible member being Hexed into a reverse concave position. When the retaining clip is fitted into the trunking, the resiliently flexible nature of the member 3 forces the first and second engaging portions in an outward direction and into abutment with the inner faces of the upper and lower walls 7, 8 of the trunking. Cables running within the trunking, shown as 12, are retained between walls 7, 8, and 1 1 of the trunking, the engaging portions 1 , 2 and member 3 of the retaining clip C.

As member 3 is forced into a concave position in order to fit the retaining clip to the trunking, a maximum cross sectional area 13 is available to the cables 12.

Preferablv, the engaging portions 1 , 2 are each provided with stabilising means to reduce lateral movement. In this embodiment the stabilising means comprises a surface 40. 42 adapted to be placed in abutment with the inner walls of the trunking so as lo provide improved stability. Of course, in other embodiments the surface is provided by a panel or one or more elements in spaced arrangement.

It is usual in trunking of the type described to provide a lip 9, 10 to the front of the upper and lower walls 7,8 used to attach the lid to the main channel. These lips help retain the retaining clip within the trunking. More preferably, there comprises one or more protruding portions, or stops 22 to abut the or each lip 9, 10, to retain the clip C within the trunking 1 1.

There may further comprise one or more protruding portions 123 to abut the rear wall of the trunking, as shown in Figure 3.

If these lips are not present, the level of resilience of member 3 needs to be greater to prevent the retaining clip being forced from the trunking. To this end, the surfaces of the engaging portions in abutment with the inner walls may be scored or etched to improve the friction characteristics.

If it is intended that the clip should not to be removed from the tanking, the first and second engaging portions 1 ,2, may be provided with adhesive pads to affix them to the trunking inner walls.

It is envisaged that the retaining clip C could be formed or moulded with the first and second engaging portions 1 , 2 in a parallel or angularly opposed relationship, so long as the separation of the surfaces of the portions 1 ,2 is greater than the separation of the inner faces of the upper and lower walls 7. 8 of the trunking, to ensure that the portions 1 and 2 are held in an abutting relationship with the inner faces of trunking inner walls 7 and 8.

In the embodiment of Figures 1 and 2. there is provided a recess 44 along each end of the engaging portions 1. 2 and the flexible member 3 is a reduced width to reduce the amount of material used. As the trunking can be provided in varying sizes, usually of a square or rectangular section such as 50mm by 50mm, 100mm by 100mm, 100mm by 50mm etc, it would be preferable to provide the retaining clip in a selection of sizes to suit the trunking being used. Thus the length 16 of the engaging portions 1 , 2 may correspond substantially to the width of the upper and lower trunking walls. While it is possible to provide a retaining clip of such a size and flexibility that it can be used in a variety of size of trunking, it is considered unlikely that a single size of retaining clip would be ideal to suit all sizes of trunking.

The width 17 of the retaining clip C is chosen so as to give the clip lateral stability in the trunking, for example in the event of a cable being pulled through the trunking without removal of the lid.

Figure 4 shows a perspective view of a plurality of retaining clips in position in a section of trunking and how they retain the cables. It also shows a retaining clip C being fitted into, or removed from the trunking 1 1 by a user U.

Figures 5 to 26 illustrate several other embodiments that are similar to the first embodiment described above, and like references have been used, but prefixed with a further number to indicate the different embodiments. Therefore only the differences will be hereinafter described.

Figures 5 and 6 show a second embodiment of the invention in which the retaining clip C is formed from a single piece of rod material, preferably a flexible steel rod. In this embodiment, the first and second engaging portion 101 , 102 and the resiliently fiexible member 3 are all formed from a single piece of flexible rod material.

It is preferred to provide the rod material with a ribbed finish as shown in Figure 6, so as to provide a level of friction between the retaining clip C and the inner walls 107, 108 of the trunking. Figure 7 shows a third embodiment of the invention. In this embodiment the first and second engaging portions 201 , 202 are formed as substantially cylindrical portions, integrally formed with the resiliently fiexible member 203. When the retaining clip C is in its free state, i.e. not fitted into the trunking, the lateral separation 18 of the outer faces of the member 203 is greater than the separation 23 of the inner edges of the lips 9, 10 of the upper and lower walls of the trunking 1 1.

When the retaining clip is fitted into the trunking, this embodiment allows the retaining clip to be pulled out from the trunking, with the first and second engaging portions 1 ,2 preventing the removal thereof. This allows a greater cross sectional area 13 (Figure 9) to be available for the cables during installation or removal. When the retaining clip C is pushed into the trunking, as shown in Figure 8, the fact that the lateral separation 19 (Figure 9) of the outer faces of the member 3 is greater than the separation 23 of the inner edges of the lips 9, 10 of the upper and lower walls of the trunking prevents the retaining clip being pushed out from the trunking by the cables 12 installed in the trunking.

If it is intended that the retaining clip should not be pulled out from the trunking in use, then the embodiment shown in Figure 7 may be modified as shown in Figure 10 by the addition of stops (or protruding portions) 322. This embodiment of the invention is shown in position in the trunking in Figure 1 1. The stops 322 engage the lips 9, 10 of the upper and lower walls of the trunking to prevent the retaining clip C being pulled from the trunking.

A further embodiment of the invention is shown in Figures 12 and 13. In this embodiment the first and second engaging portions 401 , 402 and the resiliently flexible member 403 are formed from a single piece of spring steel or plastics material. The lengths I. of the first and second engaging portions 401, 402 may be less than the width W of the inner faces of the upper and lower walls 7, 8 of the trunking 1 1 ; so as to allow the retaining clip C to be pulled out from the trunking in a fashion similar to that of the third embodiment as shown in Figure 9, or mav be of substantially the same length as the width W of the inner faces of Hie upper and lower walls 7. 8 of Hie trunking 1 1 , which in some embodiments will act to prevent the withdrawal of the retaining clip from the trunking. Although in the preceding embodiments the retaining clip is shown integially formed from a single flexibly resilient material, it is envisaged that the first and second engaging portions 1 ,2 and the resiliently flexible member 3 may be co-formed from different materials, or may be formed individually and subsequently joined together.

An example of this is shown in Figures 14 to 16. In this embodiment, the resiliently flexible member 503 as shown in Figure 14 is formed from a piece of spring steel, or plastics material having a locating hole 520 in each end. Figure 15 shows first and second engaging portions 501/502 formed separately from injection moulded plastics material, for example a thermoplastic polymer. These are fitted to the resiliently fiexible member 503 by means of locating pins/pegs 521 , which fit, into holes 520. The assembled retaining clip C is shown fitted into the trunking in Figure 16.

Figure 17 shows an embodiment of the invention in another form having a single piece of resiliently flexible material forming both the first and second engaging portions 601 , 602, and the resiliently flexible member 603. Each engaging means is provided with stabilising means, for example a surface 640. 642 for abutting the inner walls of the trunking 1 1.

Figures 18, 19 20 or 21 illustrate another embodiment of clip which is similar to the first embodiment, but of a simplified to reduce manufacturing costs. The clip C can be made from a sheet of plastics material or other foldable sheet material, for example paperboard. which is stamped out, or manufactured by injection moulding.

In this embodiment, the flexible resilient member 703 extends into a central part of the first and second engaging portions 701 and 702, and is partially separated therefrom by cuts or slots 725 to define the protiuding portions 722. The edge used to abut the rear wall of the ti Linking is provided by portion 723.

In use, the slots mav be used to hold a pluralilv of clips bv means of a guide attached to a belt or the like. A further embodiment is illustrated in Figures 22, 23, 24, 25 and 26 which is similar to the embodiment described in the previous two paragraphs in which the fiexible resilient member 803 extends into a central part of the first and second engaging portions 801 and 802, and is partially separated therefrom by cuts or slots 825 to define the protruding portions 822. The edges abuting the rear wall 6 is provided by protruding elements 823. There may furthe r comprise a thicker section 833 and 834 ofthe engaging portions to improve the rigidity of the engaging portions. The resilient member may further comprise one of more ribs 837, 839 used to impart greater rigidity to the resilient member whilst maintaining its flexural movement in the desired plane.

The first and second engaging portions 801 , 802 may be hingedly connected to the resilient member 803. Recesses 827 may be provided to reduce the amount of material used.

Although the preceding embodiments are described being formed of a variety of materials, it is preferred that the retaining clip is manufactured from an injection moulded plastics material or a rod material as both can be formed to have a smooth edge which prevents chafing of a cable in the event of it being pulled through the trunking and past any retaining clips. A plastics material has a further advantage in that it is electrically insulating in the event of a chafing of a cable.

It will be recognised that as used herein, directional references such as "top", "base", "end", "side", "upper", "lower", "width", "length", "inner" and "outer" do not limit the respective panels to such orientation, but merely serve to distinguish these panels from one another.

It can be seen from the forgoing description that the purpose of the invention is aid in the installation of cables in a trunking system, and specifically to aid in the removal and/or installation of cables in an existing trunking system. The retaining clips C are intended to be installed at the same time as the trunking is fitted, or can be fitted to the trunking at a later date when change to the cables is required.

Claims

1. A clip for the retention of cables within trunking having first and second inner walls and a removable lid section, which clip comprises a first engaging portion for engaging a first inner trunking wall, a second engaging portion for engaging a second trunking inner wall, said first and second engaging portions being joined by a resiliently flexible member.

2. A clip as claimed in claim 1 wherein the first and/or second engaging portions further comprises a stabiliser to be placed in abutment with the respective first and/or second inner walls to prevent lateral movement or twisting of the clip.

3. A clip as claimed in claim 2 wherein the stabiliser is provided by a surface of the engaging portion(s) abutting the first and/or second inner walls.

4. A clip as claimed in any one of claims 1 to 3, wherein the resiliently flexible member is formed as a substantially curved member.

5. A clip as claimed in any one of claims 1 to 4, wherein the resiliently flexible member is formed from a substantially laminar strip of resiliently flexible material.

6. A clip as claimed in any one of the preceding claims wherein the retaining clip is arranged such that the first and second engaging portions are in a planar relationship in its free position.

7. A clip as claimed in claim 5 or claim 6 wherein the first engaging portion is formed from a first panel and the second engaging portion is formed from a second panel, the first and second panels are hingedly interconnected by the resilienth flexible member.

8. A clip as claimed in claim 7 wherein the flexible member is connected to a central portion of the first and second panels and is separated at least in part along its side edges from the first and second panels by opposed slits.

9. A clip as claimed in any preceding claim wherein the flexible member further comprises one or more ribs to impart improved rigidity to the flexible member.

10. A clip as claimed in any of claims 1 to 5 wherein the first and second engaging 5 portions are formed as laterally extending members at the opposing ends of the resiliently flexible member.

1 1. A clip as claimed in claim 10, wherein said laterally extending members are cylindrical in cross section.

10

12. A clip as claimed in any of claims 1 to 5, wherein the said first and second engaging portions are also formed from substantially laminar resiliently flexible material.

15 13. A clip as claimed in claim 12, wherein the said first and second engaging portions are formed as returns at the opposing ends of the resiliently flexible member.

14. A clip as claimed in any preceding claim, wherein stops to prevent the withdrawal of the clip from the trunking are provided on the resiliently flexible member.

~> 0

15. A clip as claimed in any of claims 1 to 5, wherein the clip is formed from a rod material.

16. A clip as claimed in claim 15, wherein the surface of the rod material has a ribbed 25 finish.

17. A clip as claimed in any of claims 1 to 14, wherein finger recesses are formed at the junctions of the first and second engaging portions, and the resilienth flexible member.

30 1 8. A clip as claimed in claim 17 wherein the curv e of the resilienth flexible member is conv ex in the direction of the linger recesses.

19. A clip as claimed in any preceding claim wherein the said first and second engaging portions are integrally formed with the resiliently flexible member.

20. A clip as claimed in any preceding claim wherein the first and second engaging portions are co-moulded to the resiliently flexible member.

21. A clip as claimed in any preceding claim wherein the said first and second engaging portions and/or the resiliently flexible member are formed from an injection moulded plastics material.

22. A clip as claimed in any of claims 1 to 17, wherein the said resiliently flexible member is formed from a strip of spring steel.

23. A clip as claimed in claim 22 wherein the first and second engaging portions have projecting pins, said resiliently flexible member has holes at opposing ends thereof, said first and second engaging portions being located on said resiliently flexible member by means of said pins and holes.

24. A method of retaining cables within trunking having first and second inner walls and a removable lid section, by a clip of any of claims 1 to 23, which method comprises the steps: (v) placing one or more cables within the trunking;

(vi) sliding the first engaging portion of the clip under the wires to be engaged with the lower inner wall; (v ii) bending the flexible member and inserting the second engaging portion in the trunking so that it engages the upper inner wall; and (v iii) re-fitting the removable lid to the trunking.