GB2445110A

GB2445110A - Mounting box for trunking having pluggable connector

Info

Publication number: GB2445110A
Application number: GB0724973A
Authority: GB
Inventors: Michael David Sargent; Andrew Purdie Baker
Original assignee: Schneider Electric Ltd
Current assignee: Schneider Electric Ltd
Priority date: 2006-12-22
Filing date: 2007-12-21
Publication date: 2008-06-25
Also published as: GB0724973D0

Abstract

A mounting box 10 for an electrical wiring accessory 12, such as a power socket, is adapted for mounting in a length of electrical trunking. The mounting box has an open front with walls at the back and four side faces, and is provided on at least one side wall with a pluggable connector 14 for receiving a compatible supply wiring connector within the trunking to supply the accessory. The connector may be substantially within the mounting box, to reduce the space used up in the trunking, and the accessory may be prewired to the mounting box and tested at the factory so that it can be installed without requiring an electrician. The compatible supply wiring connector may be on the end of a cable (18, Fig 4a) or may be part of an adaptor (210, Fig 11a) which joins two mounting boxes.

Description

I

Mounting box for electrical wiring accessories, assemblies and methods of installation thereof The present invention relates to a mounting box for electrical wiring accessories, particularly, but not exclusively, to a mounting box for electrical wiring accessories for use in electrical trunking. The invention further relates to assemblies and installations of such accessories and mounting boxes and methods of installation thereof.

Electrical trunking is used as a housing for, amongst other things, electrical power cables within institutional, commercial or industrial properties. The trunking typically provides one or more channel portions which are typically plastic extrusions mounted to a wall. The power cables are housed within the channels and the channels are covered with a number of cover portions. The covers are detachably mountable to the channel portions to allow access to the power cables.

Typically, a number of electrical accessories, such as power sockets, circuit breakers, light switches and the like, are installed at various locations along the trunking. The electrical accessories are mounted to mounting boxes which are located within the channel portions of the trunking. Electrical power is delivered to the electrical accessory by wiring the power cables to the electrical accessory. The cover portions are cut to define an open portion of channel to accommodate the accessory.

An electrical accessory is typically installed by mounting the mounting box within the channel portion, wiring the power cables to the electrical accessory via apertures in the mounting box and then attaching the electrical accessory to the mounting box. The mounting box may be a snap-fit within the channel, while the accessory is secured by two or more screws so that its face plate closes the box.

Mounting electrical accessories in this manner is time consuming, since it requires the power cables to be wired to the accessory. It also requires the person mounting the accessory to have a certain level of training in view of the inherent danger in dealing with electrical power.

Pluggable wiring solutions to this are becoming widespread in building installation generally, but known solutions rely on the availability of space beside and/or behind the mounting box, which limits their acceptance in trunking situations.

It is an object of the present invention to provide a pluggable mounting system for electrical wiring accessories which is better adapted for use in conventional trunking.

According to a first aspect of the present invention, there is provided a mounting box for an electrical wiring accessory, the mounting box being adapted for mounting in a length of electrical trunking, the mounting box having an open front, a back wall and side walls at top, bottom, left and right sides, wherein the mounting box is provided on at least one of said side walls with a pluggable connector for receiving a compatible supply wiring connector within the trunking, the pluggable connector being adapted to deliver electrical power from the supply wiring connector to an electrical wring accessory.

The accessory and mounting box can then be pre-assembled and tested at a factory location, and installed easily by plugged connections on site.

Preferably, the pluggable connector is mounted in an aperture of the end face of the mounting box. This avoids increasing the depth of channel necessary for mounting.

Preferably, the aperture is formed from knock-out portions in the end face.

The same mouldings can then be used for plugged and non-plugged installations.

For one popular type of 3-pole connector (Wieland GSTI8i3), the aperture should be substantially 33mm by 15.6mm. For the 4-pole version, 47mm by 16.6mm.

Preferably, the pluggable connector is enclosed substantially within the mounting box. The length of trunking occupied is thereby not increased compared with conventional solutions.

Preferably, the pluggable connector is substantially flush with the end face of the mounting box.

Preferably, the pluggable connector includes attachment means for attaching the connector within the aperture.

Preferably, the attachment means comprises projections for snap-fitting into the aperture.

Preferably, the mounting box includes attachment means for attaching the mounting box within the trunking.

Preferably, the attachment means comprises projections for snap-fitting into the trunking.

In a preferred embodiment, a first type of projections are located on the left and right end faces of the mounting box (viewed as installed in a horizontal run of trunking).

The first projections may be positioned towards but slightly spaced from the open front of the mounting box for engaging the rear face of a cover portion at each end of the box.

In UK, for example, standard BS 4662:1970 and successor standards may be applied, the mounting box being of size UAI (unit square), US2 (double outlet), or US3 (triple outlet). The dimension between top and bottom side walls in that case will be approximately 75mm and the length between end walls approximately 75mm, 135mm or 195mm respectively.

Alternatively or, preferably, in addition, a second type of projections are located on the top and bottom walls of the mounting box for engaging complementary formations in side walls of said trunking.

In a preferred embodiment having both types of projections, the second type of projections are positioned towards the back of the mounting box, compared with the first type. The exact position will be selected for compatibility with a particular form of trunking.

Preferably, the walls and sides of the mounting box are rectangular.

Preferably, the mounting box has dimensions which conform to standards applicable in the territory. Flange portions may be provided along top and bottom edges of the mounting box open front, so as to be flush with the cover portions at the ends.

Preferably, the mounting box includes threaded bosses for attaching a conventional electrical accessory thereto.

Preferably, the mounting box includes a pluggable connector on each side wall.

Preferably, the mounting box further includes conductors so as to provide electrical continuity between pluggable connectors on said side walls of the mounting box. This allows electrical continuity to be achieved along the trunking in minimum channel depth.

According to a second aspect of the present invention there is provided an assembly for mounting in electrical trunking, the assembly comprising at least two mounting boxes according to the first aspect of the present invention and at least one pluggable supply wiring adaptor, said adaptor having at least two supply wiring connectors and a bridging portion located between and integrated with said at least two supply wiring connectors, wherein said bridging portion is adapted such that, in use, electrical power may be transmitted between pluggable connectors of adjacent mounting boxes and said at least two supply wiring connectors of said adaptor are pluggable into said at least one pluggable connector of said mounting boxes.

According to a third aspect of the present invention, there is provided an assembly for mounting in electrical trunking, the assembly comprising an electrical wiring accessory assembled together with a mounting box according to the first aspect of the invention as set forth above, wherein a face plate of the accessory closes the open front of the mounting box and wherein the pluggable connector is pre-wired together within the assembly to deliver electrical power from the supply wiring connector to the accessory without disassembly of the accessory from the mounting box.

Preferably, the area of the face plate of the accessory is larger than the area of the open front of the mounting box.

Where the mounting box includes projections of the first type, a gap is then formed between those projections and the mounting box and the underside of the face plate of the accessory. The gap can receive the trunking cover portions in the finished installation.

The mounting box may further be provided with flange portions extending along top and bottom sides abutting the face plate of the accessory, at a depth corresponding to said gap at the end walls.

Preferably, the pluggable connector does not protrude through the aperture further than the distance the face plate extends over front of the mounting box.

Preferably, the projections do not extend further than the distance the face plate extends over the front of the mounting box.

The assembly may provide a further pluggable connector on a side of the mounting box opposite to the first pluggable connector, and may include conductors providing electrical continuity between the opposite pluggable connectors as well as between the pluggable connectors and the accessory.

The conductors within the assembly which provide said electrical continuity between pluggable connectors may pass via the electrical wiring accessory.

In a preferred embodiment, the assembly includes dedicated through conductors extending directly between the opposite pluggable connectors, as well as conductors extending to the accessory.

In the preferred embodiment, the dedicated through conductors are solid rather than multi-stranded. The through conductors may have a cross-sectional area greater than 3mm2.

According to a fourth aspect of the present invention there is provided an electrical installation comprising: at least one section of electrical trunking mounted within a building; and at least one assembly according to the second aspect mounted within the trunking.

Preferably, the installation comprises a plurality of assemblies.

According to a fifth aspect of the present invention there is provided a method of installing a mounting box in a section of electrical trunking comprising the steps of: providing a mounting box having an open front with walls at the back, top and bottom sides and left and right end faces; providing at least one end face of the mounting box with a pluggable connector for receiving a compatible supply wiring connector; attaching the mounting box within the section of trunking; and plugging the supply wiring connector into the pluggable connector.

In one preferred installation, electrical continuity between sections of supply wiring is provided through plugged connections at both ends of the mounting box. This reduces space requirement, by eliminating the need for a cable running alongside or behind the mounting box.

Preferably, the method further comprises the preliminary step of wiring an electrical accessory to the pluggable connector and attaching the electrical accessory to the mounting box before the mounting box is attached within the trunking.

The preliminary step can be performed at a factory location remote from the installation site.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:-Figure 1 is a perspective view of a section of a known electrical trunking system; Figure 2 is a perspective view of a known mounting box and electrical accessory adapted for use with the trunking of Figure 1; Figs. 3a and 3b are perspective views of a mounting box for an electrical wiring accessory according to the present invention; Figure 3c is an end view of the assembled mounting box and electrical accessory of Figs. 3a and 3b mounted in electrical trunking with the trunking shown in cross-section; Figure 3d is a side view of the assembled mounting box and electrical accessory of Figure 3c; Figs. 4a and 4b are rear and front perspective views of the mounting box of Figs. 3a and 3b illustrated with supply wiring connectors, prior to final assembly; Figure 5 is a perspective view of a mounting box adapted according to a second embodiment of the invention; Figure 6 is a perspective view of a mounting box adapted according to a third embodiment of the invention; Figure 7 shows the mounting box of Figure 5 with an electrical accessory being connected and assembled thereto; Figure 8 shows the finished assembly being installed with cables in a pluggable wiring system; Figures 9a to 9d are perspective views of a pluggable supply wiring adaptor; Figures lOa to ICc are perspective views of an alternative embodiment of the adaptor of Figures 9a to 9d; Figures II a and lib are perspective views of the adaptor of Figures 9a to 9d being connected to electrical accessory mounting boxes; Figure 12 is a perspective view of the adaptor of Figures 1 Oa to I Od being connected to two pluggable connectors of an electrical accessory mounting box; and Figures 13a and 13b are perspective views of an assembly of electrical accessory mounting boxes and adaptors mounted to electrical trunking.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Figure 1 illustrates a known form of electrical trunking I which is made from plastic extrusions. A base 2 defining one or more channels 3 for electrical power cables is mounted to a wall. A main cover portion 4 can be cut so as to define openings in which mounting boxes to receive electrical accessories can be installed within the channel..

Figure 2 illustrates a typical mounting box 5 and electrical accessory 6.

The mounting box 5 is attached within the trunking 1. The electrical power cables are then fed through the back wall of the mounting box 5 and then wired to the electrical accessory 6. The electrical accessory 6 is then attached to the mounting box 5.

The known mounting box 5 has knock-out portions around its periphery, which can be removed in a configuration appropriate for wires to lead from terminals at the back of the accessory in one or both directions along the conduit. For pluggable wiring systems, these wires may be short and provided with pluggable connectors such as from the Wieland gesis range.

(See http://www.wieland-electric.de/gesis_CON.51.0. html). Space may be very tight in the trunking. If known pluggable wiring systems are used it will often be necessary to increase the size of the trunking system in one or more dimensions, or increase spacing between accessories, which reduces functionality, which increases cost.

Figures 3a to 3d illustrate a modified mounting box 10 for an electrical accessory 12. The accessory 12 is a standard component. The mounting box 10 has an open front lOa with walls lOb, lOc, lOd, lOe, lOf at the back, top and bottom sides and left and right end faces, viewed as mounted in use. Width of the box (outside top to bottom walls) is typically 75mm (BS 4662:1970). Dimensions of length vary according to the accessory wanted. A single unit (socket or switch) will have width 75mm, double 135mm and triple 195mm. Other sizes are of course possible, according to local conventions or special applications. Depth may be 25mm, 35mm or 50mm. for example.

The mounting box 10 has a pluggable connector 14 on the left end face IDe and on the right end face lOf. Each pluggable connector 14 is wired to the electrical wiring accessory 12 and is adapted to receive a compatible supply wiring connector 18 (see figure 4a). Each pluggable connector 14 is therefore adapted to deliver electrical power from the supply wiring connector 18 to the electrical wiring accessory 12. Although the mounting box 10 has been illustrated in figures 3a to 3d as comprising two pluggable connectors 14, it should be appreciated that the mounting box 10 may comprise only a single pluggable connector 14.

The mounting box 10 is adapted from a standard mounting box to include apertures 20 in each left and right end face lOe, lOf. The pluggable connectors 14 are mounted in the apertures 20. The aperture 20 may be formed by creating knock-out portions in the left and right end faces I Oe, lOf. Each pluggable connector 14 is therefore substantially enclosed within the mounting box 10.

The apertures 20 are dimensioned to receive push-fit pluggable connectors, such as Wieland Gesis con GST 18i3 series. The dimension in that case is substantially 33mm by 15.6mm.

The connection port 14a of each pluggable connector 14 is substantially flush with the respective left and right end faces lOe and lOf. A flange projects a millimetre or two, but the whole assembly fits within the length of the accessory face plate.

Each pluggable connector 14 also includes attachment means (not referenced) for attaching the connector 14 within the aperture 20. The attachment means may comprise projections which allow the connector 14 to be snap-fitted to the left and right end faces lOe, lOf. In this case the pluggable connector 14 may protrude through the aperture 20 slighiiy.

However, the connector 14 will still remain substantially flush with the end facel0e,lOf.

As best illustrated in figures 3a to 3c, the mounting box 10 also includes attachment means 22 for attaching the mounting box 10 within electrical trunking 24. The attachment means 22 are in the form of projections which are located on the left and right end faces lOe, lOf and top and bottom walls lOc, and lOd of the mounting box 10. The projections 22 are configured to allow the mounting box 10 to be snap-fitted into the trunking 24.

As illustrated in figure 3a, the projections 22 on the left and right end faces I Oe, I Of are positioned towards, but spaced from the open front I Oa of the box 10, and the projections 22 on the top and bottom walls I Oc, I Od are positioned further back, to engage complementary shoulders 25 within the side walls of the trunking channel. Flanges 23 run along the top and bottom edges of the opening 10. However, it should be appreciated that the projections 22 may be positioned in any suitable position on the left and right end faces I Oe, I Of or top and bottom walls I Oc, I Od such that the mounting box 10 may be fitting into a particular type of trunking 24, as illustrated in figures 3c and 3d.

It should also be appreciated that the mounting box 10 in a different embodiment may comprise projections 22 only on the left and right end faces lOe, 101, or only on the top and bottom walls lOc, lOd. The embodiment illustrated follows conventional mechanical design for robust compatibility with existing trunking.

With reference to figure 3a, the combined mounting box 10 and electrical accessory 12 constitute an assembly for mounting in electrical trunking.

The assembly is formed by firstly attaching the pluggable connectors 14 to the mounting box 10, as described above. The pluggable connectors 14 are then wired to the electrical accessory 12. Once the pluggable connectors 14 are wired to the electrical accessory 12, the electrical accessory 12 is then attached to the mounting box 10. This is effected by two screws 26 which are screwed through the electrical accessory 12 and into two threaded bosses 28 in the mounting box 10. These bosses may be shortened compared with conventional boxes, to avoid interfering with the connectors 14. It should be appreciated that other suitable means for attaching the accessory 12 to the box 10 may also be used. The face plate I 2a of the electrical accessory 12 therefore closes the open front l0aoftheboxl0.

Once the electrical accessory 12 has been attached to the mounting box 10, the assembly may be mounted in the trunking 24.

As illustrated in figures 3b to 3d, the area of the face plate 12a of the accessory 12 is larger than the area of the open front lOa of the mounting box 10. This produces in the finished assembly a circumferential abutment 30 between the walls 1 Ob, I Oc and faces 1 Oe, I Of of the box 10 (including flanges 23) and the underside of the face plate 12a of the accessory 12. Therefore, when the assembly is fitted into the trunking 24, the underside of the face plate 12 abuts against the cover portion 24a of the trunking 24.

The projections 22 allow the box 10 to be snap-fitted into the trunking 24.

The projections 22 abut against corresponding projections 24b in the trunking 24.

Furthermore, as illustrated in figure 3d, the cover portion 24a may also abut against the left and right end faces I Oe, 101, sandwiched between the projections 22 and the abutment 30. Flanges 23 make up the thickness of the cover, where it is interrupted for the length of the accessory (Figure 3c).

As illustrated in figures 3b and 3c, the pluggable connectors 14 do not protrude through the aperture 20 further than the distance that the face plate 12a extends over the front lOa of the mounting box 10. Also, the projections 22 do not extend further than the distance the face plate I 2a extends over the front of the mounting box 10. Therefore, the pluggable connectors 14 and the projections 22 are within the downward projected surface area of the face plate 12a.

Once the assembly has been fitted into the open trunking 24 it is necessary to connect the assembly with the supply wiring connector 18 in the trunking 24. As illustrated in figures 4a and 4b, the supply wiring connector 18 is simply plugged into the pluggable connector 14. Cover portions 24a are then fitted to close the trunking either side of the accessory.

The novel mounting box 10 thus enables the provision of pluggable wiring directly into electric mounting boxes intended for use with electrical trun king.

As the power cables in the trunking do not have to be wired to the electrical accessory 12 when installing the assembly, but are simply plugged into the pluggable connector 14, the installation of the assembly is simplified.

Furthermore, as the electrical accessory 12 is pre-wired to the mounting box 10, there is no need for the assembly to be fitted to the trunking 24 by highly qualified persons, as the assembly is snap-fitted into the trunking 24 and plugged into the power supply. Also, the assembly can be pre-tested during manufacture, which increases the speed of installation, as the installer does not need to do test any internal connections once installed.

Given a stock of these mounting boxes 10, a contractor or supplier can readily pre-assemble pluggable accessory box assemblies which have minimal height and length and which are compatible with standard trunking systems. This pre-assembly and testing can be performed at a factory location, rather than at the installation site.

The mounting box 10 can be based on a standard mounting box and modified to include the pluggable connector 14. The supply wiring connector 18 is a standard component.

In some installations such as schools and hospitals cable runs for Plug and Play systems may extend over many metres requiring cable sizes (cross-sectional area) to be increased to allow for voltage drop over the length of the cable run.

Until recently these installations have been cabled with 2.5mm2 conductors per phase. Due to extended cables runs there is now a requirement for 4mm2 conductors instead of 2.5mm2 conductors.

Conventional pluggable connectors do not allow the required number of 4mm2 conductors to be fitted easily. This can lead to increased difficulty of assembly due to the increase in physical size of the cables, and greater strain on cable terminations due to decreased bending radii of the cable.

Figure 5 shows a second embodiment of the novel mounting box 110 assembled with rigid through conductors 112 fixed to receptacles formed on the inside rear face of the box and Figure 6 shows a version 120 with them fixed within the outside face of the box. Because they are rigid conductors rather than multi-stranded flexible conductors, the desired cross-section can be achieved in a more compact form, and more easily fitted into the terminal ports of a pluggable connector. In particular, use of rigid conductor allows 4mm2 conductors to fit within the opening normally provided for a 2.5mm2 flexible conductor. The 4mm2 through conductors also extend directly between the pluggable connectors, rather than via the accessory reducing strain and congestion of space within the mounting box, and reducing the chance that the continuity of the circuit will be prejudiced by subsequent maintenance, for example.

The through conductors are secured to the mounting box primarily by being terminated in connectors 114 and 116 mounted in opposite sides of the mounting box. Each connector has a plurality of terminal ports 118 leading to screwless terminals within a plastic body. These terminals provide electrical connection and mechanical retention of the conductors simply by pushing the conductor into them. A screwdriver can be used to release the clamping mechanism if the connection needs to be disassembled in future.

The receptacles for the through conductors 112 can be provided with projections to capture the conductors even before the connectors are fitted. A central projection 122 from the receptacle wall engages with a kink 124 made in the conductor, to restrain the conductor against longitudinal sliding. Projections 126 near either end of the conductor keep its ends firmly to one side of the terminal port 118, so that flexible wiring from the accessory (not shown in Figures 5 and 6) can fit beside the rigid conductor.

Figure 7 shows the accessory 130 being connected and assembled with the through conductors 112 and pluggable connectors 114, 116. In this view it can be seen how the mounting box carcass 132 is adapted from a standard mounting box to include rectangular apertures 134, 136 in its left and right end walls. The pluggable connectors 114, 116 are mounted in the apertures. The rectangular apertures are dimensioned to receive push-fit pluggable connectors. The example illustrated has 4-pole rather than 3-pole connectors, and the cut-out dimension in that case is substantially 47mm by 16.6mm. Other types and makes of connector can of course be used, and the cut-out dimension will be adapted to suit. Each pluggable connector when assembled is substantially enclosed within the mounting box, so that its connection port is substantially flush with the end face of the box. A flange 138, 140 projects a millimetre or two, but the whole assembly fits within the length of the accessory face plate.

The accessory 130 is a standard component. Width of the mounting box (outside top to bottom walls) is typically 75mm, according to UK standards (BS 4662:1970). Dimensions of length vary according to the accessory wanted. A single unit (socket or switch) will have width 75mm, double 135mm and triple 195mm. Depth may be 25mm, 35mm or 50mm, for example. Other sizes are of course possible, according to local conventions or special applications.

The combined mounting box 110 and electrical accessory 130 constitute an assembly for mounting in electrical trunking. Once the pluggable connectors are wired to the electrical accessory by short flexible insulated conductors 144 as shown, the electrical accessory 130 is then attached to the mounting box. This is effected by two screws 146, 148 which are screwed through the electrical accessory and into two threaded bosses 150, 152 in the mounting box. These bosses and screws may be shortened compared with conventional boxes, to avoid interfering with the connectors. It should be appreciated that other suitable means for attaching the accessory to the box may also be used. The face plate 142 of the electrical accessory 130 closes the open front of the box 110.

Once the electrical accessory 130 has been attached to the mounting box, the assembly can be factory tested prior to shipping ready to be mounted in the trunking. The order of assembling these components can be selected according to convenience in several different ways. The rigid through conductors 112 can be installed in the box prior to inserting the pluggable connectors into the apertures, as illustrated in Figure 7. The flexible connectors 144 to the accessory may be inserted into the terminal ports of one of the connectors prior to insertion of the connector 114, as shown in Figure 7, or they may be inserted only after the connectors, through conductors and box carcass are assembled together. Thereceptacles for the rigid conductors are preferably moulded into the base of the box, but can be provided as a separate tray unit, if preferred. One advantage of the latter approach would be to use the same basic moulding of the box for applications with and without the through conductors. In that case, the box carcass 132 can be manufactured with rectangular knock-out portions, so that the rectangular apertures are formed only as and when required.

Figure 8 shows the finished assembly 154 of box and accessory being installed between cable sections 156, 158 which are pre-assembled with compatible plugs 160, 162. The connectors on each cable may be male and female at opposite ends, where the two connectors on the mounting box are male and female. Alternatively it may be chosen to install only male or female connectors on the boxes, and only the opposite gender on the cables. The form of box and layout shown in Figures 5 to 8 is intended for mounting in plastic or metal trunking running along the wall of the room where the accessory is to be installed. The trunking is omitted from the drawing but is of well known type. Projections 164 provide a snap fit engagement with shoulders provided along the length of the trunking channel.

The compact connectors 114, 116 allow connection of the 4mm2 solid conductors 112 and the connection of 2.5mm2 or other flexible conductors between the connector and the wiring accessory. The connectors allow the mounting box to be connected to other assemblies/ accessories. This is beneficial in that it allows heavier duty conductors to be used throughout the installation, but easily and within a small envelope i.e. the interior envelope of the mounting box. The termination of the conductors in the connectors is simplified and the number of flexible conductors in the mounting box is reduced. Guidance on terminal opening sizes for electrical accessory wiring can be found in the relevant standards, for example BS1363 Part 2 in the United Kingdom.

As the electrical accessory is pre-wired to the mounting box, there is no need for the assembly to be fitted to the trunking by highly qualified persons, as the assembly is snap-fitted into the trunking and plugged into the power supply. Also, the assembly can be pre-tested during manufacture, which increases the speed of installation, as the installer does not need to do test any internal connections once installed.

Given a stock of these mounting boxes, a contractor or supplier can readily pre-assemble pluggable accessory box assemblies which have minimal height and length and which are compatible with standard trunking systems. This pre-assembly and testing can be performed at a factory location, rather than at the installation site.

The mounting box can be based on a standard mounting box and modified to include the pluggable connector. The supply wiring connector 114, 116 is a standard component.

Figures 9a to 9d illustrate a pluggable supply wiring adaptor 210 for an electrical accessory mounting box 212 (as illustrated in Figures 1 Ia and lIb).

The adaptor 210 comprises two supply wiring connectors 214 and a bridging portion 216 located between the supply wiring connectors 214.

The bridging portion 216 is integrated with the supply wiring connectors 214.

With reference to Figures ha and I Ib, the supply wiring connectors 214 of the adaptor 210 are configured to engage with pluggable connectors 218 of electrical accessory mounting boxes 212.

As illustrated in Figure ha, the pluggable connectors 218 of the mounting boxes 212 are located on the end faces 212a of the mounting box 212.

However, as illustrated in Figure llb, the pluggable connectors 218 could be located on the top and bottom sides 212b of the mounting box 212.

This is advantageous, as it allows horizontal or vertical connection of pluggable adaptors, such as the pluggable supply wiring adaptor 210 of the present invention.

The adaptor 210 is configured to allow the transmission of electrical signals between pluggable connectors 218 of adjacent mounting boxes 212. The transmission of electrical signals may include the transmission of electrical communication signals or the delivery of electrical power. The adaptor 210 is a rigid one-piece unit which does not use sections of cable to transmit the electrical signals.

With reference to Figure 13b, the bridging portion 216 of the adaptor 210 is adapted such that, when the adaptor 210 is plugged into the pluggable connectors 218 of adjacent mounting boxes 212, an electrical connection is established between the pluggable connectors 218.

Furthermore, the bridging portion 216 may be dimensioned such that, when the adaptor is plugged into each mounting box 212, the accessory face plates 220 of each accessory 222 substantially abut against one another, as illustrated in Figure 13a. This allows a close mounting of accessories in the electrical trunking 230.

The connectors 214 and 218 in the embodiment described here take the form of Wieland GST I 8i3 (3-pole) and GST I 8i4 (4-pole) connectors.

However, it should be appreciated that any suitable form of connectors may be used. Furthermore, although the supply wiring connectors 214 of the adaptor 210 have been illustrated here as comprising one male connector and one female connector, it should be appreciated that the adaptor 210 may alternatively have two male connectors or two female connectors.

When connectors in the form of Wieland GST 18i3 and GST 18i4 are used, the bridging portion 216 may typically be 16mm in length. That is, the bridging portion 216 separates the connectors 214 of the adaptor 210 by substantially 16mm. These dimensions allow the adaptor 210 to transmit electrical signals between the pluggable connectors 218 of adjacent mounting boxes 212. However, it should be appreciated that, depending on the size and type of connection system used, the bridging portion may have alternative dimensions.

With reference to Figures 9a and 12, the adaptor 210 also comprises locking means 224. The locking means 224 comprises two slots 226 located on the bridging portion 216. Each slot 226 is adapted to engage with a corresponding locking clip 228 located on a pluggable connector 218 of a mounting box 212. Therefore, both sides of the adaptor 210 may be separately locked to a corresponding mounting box 212.

When the adaptor 210 is plugged into the pluggable connector 218 the locking clip 228 engages with the slot 226. The locking clip 226 is typically formed from plastic and snap-fits into engagement with the slot 226. The slots 226 are also dimensioned to receive an unlocking tool (e.g. a screwdriver) to unplug the adaptor 210 from the pluggable connector 218.

Providing the adaptor 210 with a locking means 224 which allows either side of the adaptor 210 to be locked with a pluggable connector 218 increases safety, as the adaptor 210 cannot easily be unplugged from the pluggable connector 218. A user must use a tool to unplug the adaptor 210.

Figures 9a to 9d illustrate the adaptor 210 as having supply wiring connectors 214 in the form of 3-pole connectors. However, Figures lOa to lOc illustrate an alternative embodiment of the adaptor 210', where the connectors 214 are 4-pole connectors.

The adaptor 210 in the embodiments described here is a one-piece plastic moulded unit. However, it should be appreciated that the adaptor 210 may be manufactured from any other suitable material and may not be manufactured as a one-piece unit.

The pluggable supply wiring adaptor 210 permits electrical accessory mounting boxes 212 to be quickly and easily connected together, as the adaptor 210 is simply plugged into the pluggable connectors 218 thereof.

This avoids the use of using wiring assemblies consisting of lengths of cable and plug sections.

Furthermore, by adapting the bridging portion 216, it is possible to reduce the gap between adjacent mounting boxes 212, which permits close mounting of accessories.

Also, the adaptor 210 is able to be manufactured and tested prior to dispatch and installation. This ensures a high level of quality due to repeatability of process and traceability. This removes problems such as bad and/or incorrect connections within the parts of the assembly.

The adaptor 210 also maintains the benefit of plug & play modular construction, where the system can be easily dismantled and rearranged as required.

Modifications and improvements may be made to the above without departing from the scope of the present invention. For example, although the electrical accessory has been described above as being an electrical power socket, it should be appreciated that the accessory could be any suitable type of electrical accessory such as circuit breakers, light switches, 3 or 4 pin plugs and the like.

Furthermore, although the mounting box 10 has been illustrated and described above as having a rectangular open front and rectangular walls and sides, it should be appreciated that the mounti ng box 10 could have an alternate shaped front, walls and sides, e.g. a circular open front etc. Also, although the mounting box 10 has been illustrated and described above as having threaded bosses for attaching the accessory 12 thereto, it should be appreciated that the box 10 may have other means for attaching the accessory thereto, for compatibility with other types of accessory.

Furthermore, although the electrical accessory has been described above as being an electrical power socket, it should be appreciated that the accessory could be any suitable type of electrical accessory such as circuit breakers, light switches, 3 or 4 pin plugs and the like.

Furthermore, although the mounting box has been illustrated and described above as having a rectangular open front and rectangular walls and sides, it should be appreciated that the mounting box could have an alternate shaped front, walls and sides, e.g. a circular open front etc. Also, although the bridging portion 216 of the adaptor 210 has been described and illustrated above as being adapted to allow adjacent face plates 220 to substantially abut one another, it should be appreciated that the bridging portion 216 could be adapted such that adjacent end faces 230 of the mounting boxes 212 could substantially abut against one another.

Also, although the adaptor 210 has been described above as being locked to the pluggable connectors 218, it should be appreciated that it could also be locked directly to the mounting box 212. 2)

Claims

Claims 1. A mounting box for an electrical wiring accessory, the

mounting box being adapted for mounting in a length of electrical trunking, the mounting box having an open front, a back wall and side walls at top, bottom, left and right sides, wherein the mounting box is provided on at least one of said side walls with a pluggable connector for receiving a compatible supply wiring connector within the trunking, the pluggable connector being adapted to deliver electrical power from the supply wiring connector to an electrical wring accessory.
2. A mounting box for an electrical wiring accessory as claimed in claim 1, wherein the pluggable connector is mounted in an aperture of the side wall of the mounting box.
3. A mounting box for an electrical wiring accessory as claimed in claim 2, wherein the aperture is formed from knock-out portions in the wall.
4. A mounting box for an electrical wiring accessory as claimed in any preceding claim, wherein the pluggable connector is enclosed substantially within the mounting box.
5. A mounting box for an electrical wiring accessory as claimed in any preceding claim, wherein the pluggable connector is substantially flush with the wall of the mounting box.
6. A mounting box for an electrical wiring accessory as claimed in any preceding claim, wherein the pluggable connector includes attachment means for attaching the connector within the aperture.
7. A mounting box for an electrical wiring accessory as claimed in claim 6, wherein the attachment means comprises projections for snap-fitting into the aperture.
8. A mounting box for an electrical wiring accessory as claimed in any preceding claim, wherein the mounting box includes attachment means for attaching the mounting box within the trunking.
9. A mounting box for an electrical wiring accessory as claimed in claim 8, wherein the attachment means comprises projections for snap-fitting into the trunking.
10. A mounting box for an electrical wiring accessory as claimed in claim 9, wherein a first type of projections are located on side walls forming left and right end faces of the mounting box (viewed as installed in a horizontal run of trunking).
II. A mounting box for an electrical wiring accessory as claimed in claim 10, wherein the first projections may be positioned towards but slightly spaced from the open front of the mounting box for engaging the rear face of a cover portion at each end of the box.
12. A mounting box for an electrical wiring accessory as claimed in any preceding claim, wherein flange portions may be provided along top and bottom edges of the mounting box open front, so as to be flush with the cover portions at the ends.
13. A mounting box for an electrical wiring accessory as claimed in any of claims 9 to 12, wherein a second type of a second type of projections are located on the top and bottom walls of the mounting box for engaging complementary formations in side walls of said trunking.
14. A mounting box for an electrical wiring accessory as claimed in claim 13, wherein the second type of projections are positioned towards the back of the mounting box, compared with the first type.
15. A mounting box for an electrical wiring accessory as claimed in any preceding claim, wherein the walls and sides of the mounting box are rectangular.
16. A mounting box for an electrical wiring accessory as claimed in any preceding claim, wherein the mounting box has dimensions which conform to standards applicable in the territory.
17. A mounting box for an electrical wiring accessory as claimed in any preceding claim, wherein the mounting box includes threaded bosses for attaching a conventional electrical accessory thereto.
18. A mounting box for an electrical wiring accessory as claimed in any preceding claim, wherein the mounting box includes a pluggable connector on any two of said walls.
19. A mounting box for an electrical wiring accessory as claimed in claim 18, wherein the mounting box includes pluggable connectors on two opposing walls.
20. A mounting box for an electrical wiring accessory as claimed in claim 19, wherein the two opposing walls form the left and right end faces of the box (viewed as installed in a horizontal run of trunking).
21. A mounting box for an electrical wiring accessory as claimed in any of claims 18 to 20 further including conductors so as to provide electrical continuity between pluggable connectors on said side walls of the mounting box.
22. A mounting box for an electrical wiring accessory as claimed in claim 21, wherein the conductors extend between the pluggable connectors on said side walls of the mounting box.
23. A mounting box for an electrical wiring accessory as claimed in claim 21 or claim 22, wherein the conductors are rigid.
24. A mounting box for an electrical wiring accessory as claimed in claim 23, wherein the rigid conductors are metal rods with a cross-sectional area in excess of 3mm2.
25. A mounting box for an electrical wiring accessory as claimed in claim 23 or claim 24, wherein the mounting box is provided with receptacles to receive and retain respective conductors.
26. An assembly for mounting in electrical trunking, the assembly corn prising: at least two mounting boxes according to any of claims I to 25; and at least one pluggable supply wiring adaptor, said adaptor having at least two supply wiring connectors and a bridging portion located between and integrated with said at least two supply wiring connectors, wherein said bridging portion is adapted such that, in use, electrical power may be transmitted between pluggable connectors of adjacent mounting boxes and said at least two supply wiring connectors of said adaptor are pluggable into said at least one pluggable connector of said mounting boxes.
27. An assembly for mounting in electrical trunking, the assembly comprising an electrical wiring accessory assembled together with a mounting box according to any of claims I to 25, wherein a face plate of the accessory closes the open front of the mounting box and wherein the pluggable connector is pre-wired together within the assembly to deliver electrical power from the supply wiring connector to the accessory without disassembly of the accessory from the mounting box.
28. An assembly as claimed in claim 27, wherein the area of the face plate of the accessory is larger than the area of the open front of the mounting box.
29. An assembly as claimed in claim 27 or claim 28,, wherein, where the mounting box includes projections of the first type, a gap is then formed between those projections and the mounting box and the underside of the face plate of the accessory.
30. An assembly as claimed in claim 29, wherein the mounting box may further be provided with flange portions extending along top and bottom sides abutting the face plate of the accessory, at a depth corresponding to the gap at the end walls.
31. An assembly as claimed in any of claims 27 to 30, wherein the pluggable connector does not protrude through the aperture further than the distance the face plate extends over front of the mounting box.
32. An assembly as claimed in any of claims 27 to 31, wherein the projections do not extend further than the distance the face plate extends over front of the mounting box.
33. An assembly as claimed in any of claims 27 to 32, including a further pluggable connector on a side of the mounting box opposite to the first pluggable connector, and further including conductors providing electrical continuity between the opposite pluggable connectors as well as between the pluggable connectors and the accessory.
34. An assembly as claimed in claim 33, wherein conductors within the assembly which provide said electrical continuity between pluggable connectors pass via the electrical wiring accessory.
35. An assembly as claimed in claim 33, wherein the assembly includes dedicated through conductors extending directly between the opposite pluggable connectors, as well as conductors extending to the accessory.
36. An assembly as claimed in claim 35, wherein the dedicated through conductors are solid rather than multi-stranded.
37. An electrical installation comprising: at least one section of electrical trunking mounted within a building; and at least one assembly according to any of claims 26 to 36 mounted within the trunking.
38. An electrical installation as claimed in claim 37, wherein the installation comprises a plurality of assemblies interconnected by plugged supply wiring sections.
39. An installation as claimed in claim 38, wherein electrical continuity between adjacent supply wiring sections and assemblies is provided through the assemblies.
40. A method of installing a mounting box in a section of electrical trunking comprising the steps of: providing a mounting box having an open front with walls at the back, top and bottom sides and left and right end faces; providing at least one end face of the mounting box with a pluggable connector for receiving a compatible supply wiring connector; attaching the mounting box within the section of trunking; and plugging the supply wiring connector into the pluggable connector.
41. A method of installing a mounting box in a section of electrical trunking as claimed in claim 40, wherein electrical continuity between sections of supply wiring is provided through plugged connections at both ends of the mounting box.
42. A method of installing a mounting box in a section of electrical trunking as claimed in claim 40 or 41, wherein the method further comprises the preliminary step of wiring an electrical accessory to the pluggable connector and attaching the electrical accessory to the mounting box before the mounting box is attached within the trunking.