GB2430087A

GB2430087A - Mounting box for electrical wiring accessories with pluggable connector

Info

Publication number: GB2430087A
Application number: GB0617639A
Authority: GB
Inventors: Keith Wray Ball; Andrew Purdie Baker; Michael David Sargent
Original assignee: Schneider Electric Ltd
Current assignee: Schneider Electric Ltd
Priority date: 2005-09-10
Filing date: 2006-09-08
Publication date: 2007-03-14
Anticipated expiration: 2026-09-08
Also published as: GB2430087B; GB0617639D0

Abstract

A mounting box 10 for an electrical wiring accessory 12 has a connector 16 on the outside. The mounting box is adapted to fit through an aperture in a wall panel and has an open front side for receiving the accessory. The connector 16 plugs into supply wiring 15, 15' behind the panel and is connected to the accessory through an aperture in a wall of the box. The supply connection is a pluggable connection with a compatible connector 18, 18' on the supply wiring. This allows the mounting box and accessory to be supplied as a sealed unit.

Description

I

CONNECTOR AND MOUNTING BOX FOR ELECTRICAL

WIRING ACCESSORIES, AND METHODS AND INSTAL.LATIONS INCLUDING THE SAME The invention relates to connectors and mounting boxes for electrical wiring accessories, in particular for use in pluggable wiring installations.

The Invention further selates to methods of Installing such accessories and Installations including the same.

Mounting boxes for fittIng electrical accessories such as power outlet sockets/light switches and the like are well known. These boxes are fitted into either a solid brick or plastered wall, or a hollow plasterboard, or similar style wall. In the case of solid walls, the boxes are usually fixed by means of screws Into the wall through the rear wail of the box. In the case of plasterboard hollow walls, some form of flexible clip or bracket is used to grip the rear of the wall board, the box being inserted Into the wait from the front. The accessory with its facia Is then connected to wiring and fitted Into the mounting box, covering the front of the box and being secured, typically with a pair of standard screws.

For large commercial Installations, there is nowadays the option to use pre-fabricated wiring with plugged connections, for example of the WIELAND GESIS type. The advantage is that the final installation work can be performed more quickly and, to some extent, by less skilled personnel than conventional wiring installation. Testing of the connections can largely be performed at the factory.

Particula,ly when a building is being constructed or re-fitted, there is relatively easy access to the interiors cavities of walls, floors and ceilings.

Nevertheless, the known accessory/mounting box designs all require a relatively labour-Intensive process of fitting of the open mounting box connecting the accessory electrically and screwing the accessory into place over the box opening. Known cable leads and connectors add to the complexity of the installation and can give rise to access problems in later life.

It Is accordingly an object of the Invention to enable the connection of wiring accessories to pluggable wiring with a rugged and secure mounting while achieving a significant labour saving over known systems. The terms "front", "forward" and "rear" are used below as if the accessory Is in place in a wail, facing towards a user, and should be interpreted figuratively when the connector or assembly is not mounted, or Is mounted In a floor or ceiling, for example.

The invention In a first aspect provides in combination a connector and a mounting box for an electrical wiring accessory, the mounting box being adapted for fitting through an aperture In a wait panel and having an open front side for receiving the accessory, the connector being adapted for making at least one suppiy connection to obtain electrical power from supply wiring behind the panel and an accessory connection for delivering said electrical power to the accessory via an aperture in a wall of said mounting box, wherein the supply connection is a pluggable connection requiring a compatible connector to be provided on the supply wiring.

The accessory connection preferably has a form more compact than the pluggable connection indudlng compatible connector.

The connector may comprise an Insulating housing adapted to fix to the wail of the box In the vicinity of said aperture. In this way the accessory connection can be Isolated mechanically from the supply connection, permitting a more compact, lightweight and cheaper construction than the standard pluggable wiring connectors.

A part of the oonnector housing which makes said accessory connection may be formed so as to fit within the aperture in the wall of the box, whereby the accessory connection when made is contained within the mounting box white the plugged supply connection Is made outside the mounting box.

SaId part of the housing may project into the box when fitted.

The connector housIng may Include projections for snap-fitting into one or more apertures In the mounting box. Alternatively orin addition, the mounting box may include projections for snap-fitting into one or more apertures In the connector housing.

The connector housing may be arranged to engage with a removable fixing part, the fixing part being assembled onto the housing through the aperture In the box wall In order to fix the connector housing to the box.

The fixing part may be formed to serve as a shroud for said terminals.

Part of the connector housing may alternatively be integrated with the mounting box.

The accessory connection may comprise a pluggable connection for mating directly with a complementary pluggable connection on the rear of the accessory when the accessory Is fitted to the front of the box.

The accessory connection may comprise a plurality of cable terminations, for example of screw or spring type, for forming a wire connection to the accessory.

The invention as set forth herein Can be applied in combination with another invention described in our patent application GB0518497.3 (Agent's ref 65171 GB) to provide an arrangement, which can be easily fitted during initial assembly, but more importantly can be mounted as a complete assembly with the accessory top already fitted and wired.

The connector may provide pluggabte connections accessible outside the mounting box for connection to two supply cables so as to form part of a ring main. The pluggable connections on the connector may be male and female so that said cables can be joined directly to maintain the ring main in the event that the accessory is to be disconnected.

The combination may further include the electrical wiring accessory itself, for example a standard mains outlet socket appropriate to the territory of the installation.

The invention further provides a mounting box for an electrical wiring accessory, the mounting box being adapted for fitting through an aperture in a waif panel and having an open front side for receiving the accessory and access for electrical connections toward a rear side thereof, wherein said access for electrical connections comprises a connector preassembled into the rear side of the mounting box for providIng a pluggable connection to pre-assembled plugged-in wiring to the rear of the mounting box, the connector further providing terminals for connection of the accessory to plugged-in wiring through the pluggable connection.

The connector may further be adapted to provide a second pluggable connection to connect to the accessory without wiring, when said accessory Is mounted on the front side of the mounting box.

The invention in a further aspect provides an electrical wiring accessory and a mounting box for mounting said accessory to a wafi panel, the mounting box providing a first connector pluggable to wiring behind said waR panel and a second connector internal to the mounting box and mating with a compatible connector on said accessory when the accessory Is mounted to the mounting box.

The first and second connectors in such a case may be formed In an Integral socket block which penetrates a wall of the mounting box. The socket block may be dimensioned so as to fix In an aperture of the box waIl. The socket block may arranged to be released from the aperture by a predetermined manual operation. Said removal operation may include separation of a fixing part from the socket block. The fixing part my serve also as a shroud for terminals within the mounting box. The socket block may provide a third connector for connection to further wiring behind the wall panel, for example to Implement a ring main configuration.

The Invention yet further provides a method of installing electrical accessories In a building, the method comprising (In no specific order): providing supply wiring through the building or a part of the building, said supply wiring including a plurality of supply plugs pre-fitted to ends of supply cables; - providing a plurality of accessory units each comprising an electrical accessory and a compatible mounting box and connector combination according to the invention aspect as defined above; and - mounting said accessories in or on wall panels of the building using said mounting boxes and electrically connecting each accessory to said supply wiring via the connectors.

in a preferred embodiment of this method, the connectors are mounted mechanically to the mounting boxes, such that the accessory connection is mechanically isolated from forces on the supply connection.

In a particularly preferred embodiment, each connector Is tixed within an aperture in a wall of the mounting box (for example a rear wall)

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described, by way of example only, by reference to the accompanying drawings, in which: Figure 1 shows in cut-away detail a novel accessory/mounting box assembly Including a connector according to a first embodiment of the invention having plugged connection to the accessory; Figure 2 shows a similar assembly to that of Figure 1, this time from the rear with plugged wiring fitted, and in a second embodiment having wired connections to the accessory; and Figures 3 to 7 show in more detail the connector and associated parts in the embodiment of FIgure 2, with a first version being shown in Figures 3.

and 7 and a second version beIng shown in Figures 4 and 6.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Figures 1 and 2 show two alternate assemblies of a novel mounting box and electrical accessory 12 suitable to be mounted through a wall panel such as plasterboard. The panel will typically be one side of a double-sided cavity wall where the electrical cables run. When a building is being fitted for the first time, or being radically re-fitted, the rear of panel may be fully accessible because the other panel of the cavity wall is not yet fitted. Cables 15, 15' within the walls of a building are coupled to the accessory by means of a rear socket block 16 which projects from the mounting box, as shown in Figure 2. In the preferred embodiments, the socket block 16 is secured mechanically in an aperture in the rear wall of the box, so that the mechanical connection is rigid and connections within the box are isolated from any strain on the cable installation. Note that male and female connectors are provided on opposite sides of socket block 16, so that the cables 15, 15' can be patched together by their plugs 18,18'.

From the front at least, the accessory in this Illustration is a standard switched mains outlet socket (UK 13 amp standard, single or dual type), but other accessories including different types of outlets, isolators, light switches and so on can all be envisaged as part of the same system. The terms "front", "forward" and rear are used as If the accessory Is In place in a wall, facing towards a user, and should be interpreted figuratively when the assembly Is not mounted, or is mounted in a floor or ceiling, for

example.

A clamping mechanism is provided in the side wall at each end of the mounting box 10, and comprises primarily a clamping arm 22 and lead screw 24. The box side wall includes a slot or recess allowing the arms 22 to swing into a retracted position within the box. A stop engages part of the box to limit the retraction once the arm is flush with the sides of the box 10. Each lead screw 24 has a slotted head readily accessible at the rear side of the box 10, and is free to rotate while being restrained axially. The damping arm 22 is intemafly threaded, and forms a friction fit onto the threaded lead screw. More detail of the mounting mechanism and its operatIon Is provided In our co-pending patent application GBO51 8497.3 (Agent's ref 65171GB), from which the present application claims priority.

In summary, the complete wired accessory with box can be inserted through the front aperture of the wall and then tightened from the rear by means of the clamping dip. The rear wiring is then attached to the rear socket block 16. The accessory 12 is mounted to the box 10 using screws in the conventional manner, and so can be removed and replaced as desired for access to the connections within.

In the Figure 1 example, filling and removal of the accessory 12 is made easier by replacing a conventional wired connection to the lower plug/socket with the provision of a further pluggable connector 38 compatible with mating connectors 40 on the rear socket block 16, mounted In the rear wall of box 10. A range of accessories can be manufactured with compatible pluggable connectors 38 so that these mate automatically on assembly of the accessory 12 to the mounting box 10.

FIgure 2 shows a version where the pluggable connectors 38,40 are not provided and more conventional wire connections 42 are provided within the assembly to connect the electrical parts of the accessory 12 to corresponding terminals 44 on the top of the socket block 16. Further detail of this type of connector will be described below with reference to Figures 3 onward.

In either case, the top cover is removed by undoing the two fixing screws 35 and then lifting upwards to disengage the connectors 38, 40 (FIgure 1 version) or provide access to the short wired connections (Figure 2 version). If the mounting box Is also to be removed from the wall, lead screws can be operated from within the box to retract the clamping arms 22 from behind the wall panel. As a further option1 socket block 16 may be detachable from the rear of the box 10 so that the box can then be removed from the wait to reveal the cabling connectors within the wall.

In all of the examples shown, the novel mounting box provides additional flexibility for pre-assembly and rapid installation, while retaining the familiarity, security and compatibility of conventional mounting systems.

The concept of providing the mounting box with a pluggable connector for pre-assembled wiring adds flexibility also. Figure 1 illustrates that this facility can be extended to Include pluggable connections between the mounting box and the accessory itself, albeit with the expense of requiring suItably modified accessories. The requirement for cutting wires, stripping insulation and making screw terminal connections can be completely eliminated if desired.

FIgure 3 shows in more detail the fitting of socket block 16 into an aperture In the base of mounting box 10. Short wires 42 emerge Into the box from terminals (44, Fig. 2) on top of the socket block, for connection to the accessory 12 (not shown). A shroud 46 is provided to cover the terminals.

The shroud snap-fits to an upper part of the socket block, at the same time fixing the assembly within a specIally shaped aperture 48 in the rear wall of mounting box 10. ProjectIons 47 (seen in Figure 6) provIded on the upper part of the socket block 16 engage with corresponding apertures or recesses in the shroud 46 to provide this snap fit action. A grip 52 is provided at each side of the shroud piece to engage the within the opening 48 of box 10 to prevent movement.

Figures 4 and 5 show two versions of the socket block and shroud assembly separately from the box. In the Figure 4 version, the wires 42 emerge parallel with the box wall, rather than perpendicularty. Openings in the top of the shroud part allow operation of screws or other damping means within terminals 44. in the Figure 5 version, the wires emerge from the terminals at the top' of the socket block, perpendicular to the wall of the mounting box 10. The shroud part can be identical if the connector is to be produced in both versions.

IC) Figures 6 and 7 show the same two versions of the connector with the shrouds removed. In Figure 6 the terminals 44 can be seen with screw tightening at 54. In Figure 7, the terminals 44 are of a crimp type. Snapfit projections 47 can be seen on the socket body 16, as mentioned above. It goes without saying that crimped and screw terminals can be combined with parallel and perpendicular arrangements in different ways without departing from the scope of the Invention.

In an alternative embodiment, it may be possible for the socket block to be to inserted (or withdrawn) through the aperture 46 with shroud and wires 42 already assembled to it. prior to connection to the accessory 12. A different shape of aperture 48 and/or the other components can be adopted, which both admits the connector and shroud assembly and, by snap-fitting or other means fixes the assembly to the mounting box and constrains it against sliding and twisting once In place.

Further modifications are of course possible within the spirit and scope of the Invention in its various aspects, and the examples Illustrated and described above are not to be taken as limiting on the scope of protection sought. The exact form of the mounting box and accessories can vary according to the application, national standards and so forth. The socket block may clip or grip into the mounting box aperture independently of any shroud or other part, or separate fixing parts may be provided to cooperate with the block and the box wall. The aperture 48 may have a special non-rectangular, non-round shape as shown in Figures 3 to 8, or it may be more rectangular, as shown in FIgures 1 and 2. The accessory 12 may be entirely Integrated with the front cover plate, as shown, or the assembly may come in three parts, wfth the cover plate separate from the working parts of the accessory. The accessory may in other instances comprise only a cover plate, where a mounting box and connections are provided to allow for some future requirement. I')-

Claims

1. In combination a connector and a mounting box for an electrical wiring accessory, the mounting box being adapted for fitting through an aperture in a wall panel and having an open front side for receiving the accessory, the connector being adapted for making at least one supply connection to obtain electrical power from supply wiring behind the panel and an accessory connection for delivering said electrical power to the accessory via an aperture in a wall of said mounting box, wherein the supply connection is a piuggable connection requiring a compatible connector to be provided on the supply wiring.

2. A combination as claimed In claim I wherein the accessory connection has a form more compact than the pluggabie connection including compatible connector.

3. A combination as claimed in claim 1 or 2 wherein the connector comprises an insulating housing adapted to lix to the wall of the box in the vicinity of said aperture.

4. A combination as claimed In claim 3 wherein a part of the connector housing which makes said accessory connection may be formed so as to fit within the aperture in the wall of the box, whereby the accessory connection when made is contained within the mounting box while the plugged supply connection is made outside the mounting box.

5. A combination as claimed in arty of claim 5 wherein said part of the housing projects into the box when fttLc.j.

6. A combination as claimed in claim 3,4 or 5 wherein the connector housing Includes projections for snap-fitting into one or more apertures in the mounting box.

7. A combination as claimed in claim 3, 4, 5 or 6 wherein the mounting box includes projections for snap-fitting into one or more apertures in the connector housing.

8. A combination as claimed In any of claims 3 to 7 wherein the connector housing is arranged to engage with a removable fixing part, the fixing part being assembled onto the housing through the aperture In the box wall in order to fix the connector housing to the box.

9. A combination as claimed in claim 8 wherein the fixing part is formed to serve as a shroud for said terminals.

10. A combination as claimed in any of claims 3 to 9 wherein part of the connector housing is integrated with the mounting box.

11. A combination as claimed in any preceding claim wherein the accessory connection comprises a pluggable connection for mating directly with a complementary pluggable connection on the rear of the accessory when the accessory Is fitted to the front of the box.

12. A combination as claimed in any of claim 1 to 10 wherein the accessory connection comprises a pIur:iity of cable terminations for forming a wire connection to the accesiory.

13. A combination as claimed in any preceding claim wherein the connector provides piuggabie connecti s accessible outside the mounting box for connection to two supply cables so as to form part of a ring main.

14. A combination as claimed in claim 13 whereIn the pluggable connections on the connector are complementary male and female so that said cables can be joined directly to one another to maintain the ring main In the event that the accessory is to be disconnected.

15. A combination as claimed in any preceding claim further induding the electrical wiring accessory itself.

16. A mounting box for an electrical wiring accessory, the mounting box being adapted for fitting through an aperture in a wall panel and having an open front side for receiving the accessory and access for electrical connections toward a rear side thereof, wherein said access for electrical connections comprises a connector pre-assernbled into the rear side of the mounting box for providing a pluggable connection to pre- assembled plugged-in wiring to the rear of the mounting box, the connector further providing terminals for connection of Ii accessory to plugged-In wiring through the piuggable connection.

17. A mounting box as claimed in cirn 16 wherein the connector may further be adapted to provide a second pluggable connection to connect to the accessory without wiring, when saiu accessory is mounted on the front side of the mounting box.

1$. In combination an elecuicl wir accessory and a mounting box for mounting said accessory to a wall LtrIc, the mounting box providing a first connector pluggable to wiri be.1d wall panel and a second connector internal to the mounting box and mating with a compatible connector on said accessory when the accessory is mounted to the mounting box.

19. A combination as claimed In dalm 18 wherein the first and second connectors are formed in an Integral socket block which penetrates a wall of the mounting box.

20. A method of installing electrical accessories In a building, the method compnsing (in no specilic ordef): - providing supply wiring through the building or a part of the building, said supply wiring including a plurality of supply plugs pre-fitted to ends of supply cables; - providing a plurality of accessory units each comprising an electrical accessory and a compatible mounting ox and connector combination accordIng to the invention aspect as dtned above; and - mounting said accessories in or on wail panels of the building using said mounting boxes and electrically connecting each accessory to said supply wiring via the connectors.

21. A method as claimed li claim 2u wherein the connectors are mounted mechanically to the mounting uoxs, such that the accessory connection Is mechanically isolated from forces on the supply connectIon.

22. A method as claimed in claim 20 and 21 wherein each connector is fIxed within an aperturc a thc.outng box.

23. An electrical ins(1atio coinprLg a piurlity of accessories mounted to walls of a building and each connected to plugged mains wiring by means of connectors wd mo. ding boxes as claimed in any of claims 1 to 19. ltD

24. A mounting box and connector combination substantially as described herein with reference to any of the accompanying drawings.

25. An electrical acccssory, mounting box and connector combination substantially as described herein with reference to any of the accompanying drawings.

26. A method of installing electrical accessory substantially as described herein with reirence to the xompanying drawings.

27. An electrical installation wherein a plurality of electrical wiring accessories have been mounted and connected to supply wiring using connectors and mounting boxes substantially as described herein with reference to the accompnyiiig thawir.