GB2404097A - Wall Mounted Electrical Connector Module - Google Patents

Abstract

The present invention is an electrical connector module for use in conjunction with a wall box when furnishing fixed wiring in a building. The connector module comprises a body 16 configured to locate in a wall box 10 for an electrical component such as a socket for an external plug or a switch. The connector module defines at least one wire terminator 21, 22, 23 to which an individual wire 27 of a cable may be connected. It also comprises at least one socket 28, 29, 30 which faces outwardly of the wall box 10, whereby an electrical component 33 having at least one rearwardly-directed conductor pin 38, 39, 40 may connect directly to the connector module on offering the component to the wall box. This allows easier modular connection of electrical components.

Description

ELECTRICAL CONNECTIONS

This invention relates to an electrical connector module for use in conjunction with a wall box, to facilitate the furnishing of the fixed wiring of a building. Further, the invention relates to such an electrical connector module in combination with a wall box. In addition, the invention relates to an electrical component suitable for use with a connector module of this invention.

The usual procedure for providing the fixed wiring during the construction of domestic or other buildings is for the installation to be completed in two stages. In the first stage - usually referred to as first-fixing wall boxes are 0 secured to the walls at the required positions for the mains outlets, switches and so on, and wires are run around the walls from a consumer unit or other distribution point to the wall boxes. There, the wires are cut to leave a tail of typically 10 to 20 cm; the tail is then curled up and left for the second stage of the installation procedure, usually referred to as second-fixing.

Once the first-fixing has been completed, the walls are rendered and plastered. When completed, the second-fixing is performed. In this, the tails are uncurled from the wall boxes and excess render and plaster is removed from the boxes. The wires are then terminated to the required electrical components, such as socket outlets, switches, dimmer controls, movement so sensors and other detectors and so on. Finally, the components are secured to the wall boxes. The termination of the wires mostly is performed by stripping insulation from the last few mm of each wire and then securing the wire to a connection block of the component, using a screw clamping arrangement within the connection block. Thus, the second-fixing is relatively time consuming and - 2 moreover slightly awkward, in that the connection block is normally provided on the rear face of the component being fixed and so a sufficient length of tail must be left, to permit access to the rear of the component. When the wires have been connected, the component must be manoeuvred as required so that the component may be screwed down to the wall box. During this, the tail must be curled round so as to be accommodated in the wall box, without restricting the location of the component.

The above procedures may be adopted during the construction of various buildings including domestic dwellings, but many industrial and office buildings employ surface conduits with surface-mounted wall boxes. Such an installation may be implemented following the completion of the basic building construction. As such, the separation of the first and secondfixings by the rendering and plastering procedures is not an issue. Nevertheless, there is still the difficulty of completing the secondfixing, in that access must still be gained to the rear of a component to be secured to a wall box followed by the securing of the component to the wall box.

The present invention, in its various aspects, aims to simplify the second-fixing procedure usually associated with the wiring installation of a domestic dwelling, but maybe also for other buildings as well. Further, though the first-fixing will take slightly longer to perform by adopting the measures of this invention, it is a further aim to make the last part of first-fixing more convenient and easier to perform than the current second-fixing procedure.

According to a first aspect of this invention, there is provided an electrical connector module for use in conjunction with a wall box in furnishing - 3 the fixed wiring of a building, which connector module comprises a body configured for reception in a predefined location in a wall box for an electrical component, the connector module defining at least one wire terminator to which an individual wire of a cable may be connected, and at least one socket which faces outwardly of the wall box when the connector module is received therein, whereby an electrical component having at least one rearwardly-directed conductor pin may connect directly to the connector module on offering the component to the wall box.

The module of this invention may much simplify the overall procedure of 0 providing fixed wiring within a building. However, it is necessary for special electrical components to be provided to co-operate with the modules; as such, conventional electrical components such as socket outlets, switches and so on cannot be employed. By using the module of this invention, the termination of the fixed wires may relatively easily be accomplished, since the electrical component is not present at that stage. Further, that termination is undertaken at the time of the firstfixing. Then, following rendering and plastering of the walls, the secondfixing is very simple to undertake and merely requires the offering of a component to the wall box so as to connect electrically to the module, followed by the attachment of that component by conventional screws.

So The system may of course be used in a building where no rendering and plastering is employed; in this case, the electrical components are mounted to the wall boxes as soon as the wiring to the modules is completed.

When implementing a wiring installation using modules of this invention, following the installation of the wall boxes and the running of wires to those - 4 boxes, the wires are immediately terminated to the modules. As compared to a conventional electrical component, the module has no large face plate and so access to the connection points of the module is relatively easy. Further, no relatively long tail need be left for subsequent accommodation in the wall box, since there is no need to be able to remove the module from the wall box after the termination of the wires thereto. Once completed, the walls may be rendered and plastered and the second-fixing undertaken as mentioned above.

The connector module may have only one or maybe two wire terminators and a corresponding number of sockets, though a typical module will have three wire terminators and three sockets. Each socket is electrically connected within the connector module to a respective wire terminator. Alternatively, the module may have more than three wire terminators in order to allow more flexible use of the module. For example, the module may have six terminators arranged in directly-coupled pairs, to permit the installation of a ring circuit. In the case of a module intended for use with lighting circuits, the module may also include one or more terminators which are not connected to any of the sockets; this permits a loop-through to be wired.

In the United Kingdom, most electrical components have screw-type wire terminators, though in some other countries push-fit terminators are commonly employed on many electrical components. The module of this invention may also have push-fit terminators, especially for modules intended for use with lighting circuits. Clamping screw-terminators are preferably employed for relatively heavy-duty power circuits. For the case of screw-terminators, the screws may be accessible from the side of the module opposed to that provided with the sockets, such that those screws face the rear surface of the wall box when the module is installed in the wall box. In this way, the screws will be protected from inadvertent contact and also from splashes of render or plaster, during the finishing of the walls.

Most advantageously, the sockets of the module (in which are received the rearwardly-directed conductor pins of an electrical component) are arranged irregularly on the face of the module which is directed outwardly when fitted to a wall box. Of course, the electrical component must have a matching arrangement of conductor pins and in this way, the connections to the electrical component cannot be implemented incorrectly. A removable cover for the sockets may be provided on the connector module, in order to protect the sockets until an electrical component is to be connected thereto. Such a cover will prevent splashes of render or plaster entering the sockets during finishing of the walls and so serve to reduce cleaning-up, during the second-fixing stage.

The connector module may be provided with means to restrain the module within the wall box at a predefined position, once the module has been pressed home in the wall box. The position may be defined by co-operating pegs and recesses in the wall box and module, or by providing channels, upstanding components or other means for ensuring the module can be fitted so into the wall box only in one position, in a predefined orientation. Once installed, the module may be restrained in the wall box by co-operating resilient claws on one of the module or wall box and engageable with corresponding faces on the other of the module or wall box.

Not infrequently, and particularly when refurbishing an existing wiring installation, it happens that a wall box is buried deeper below the surface of a skim coat (plaster) on a wall than usually is the case. It is already known to allow the accommodation of this by providing extra- long screws for the attachment of an electrical component to such a wall box, but if an attempt is made to implement the measures of the present invention, it could be that the connector module is so far below the surface of the wall that no contact will be achieved between the conductor pins of the electrical component and the sockets of the module. Potentially more serious could be if there is only an inadequate contact, leading to a risk of overheating.

In order to address the above situation, means may be provided to permit adjustment of the position of the module within a wall box, towards and away from the base of the wall box such that an adequate electrical connection with an electrical component may be achieved. Various adjustment mechanisms may be employed for this purpose but one particularly preferred arrangement is to have at least two screw-threaded adjusters, threaded into the module and engaging a base wall of the wall box or a carrier for the module, fitted into the wall box. An alternative possibility would be to provide at least two sets of frangible legs of different lengths, whereby at least the longest legs and To possibly also further legs may be broken away from the module until the module is correctly disposed within the wall box. With either of these possibilities, a generally U-shaped carrier may first be fitted into the wall box, and the module is slidingly interengaged with that carrier.

This invention extends to the combination of a wall box for an electrical component and a connector module of this invention as described above, wherein the wall box is profiled to define a location for accommodating the i connector module. In the combination, the wall box may be moulded from a I plastics material, the wall portions of that wall box being suitably profiled to define the location and orientation of the module. In such a case, the wall box also should carry suitable markings to indicate the required orientation of the wall box when secured to a wall whereby an electrical component connected to the module and secured to the wall box also will have the appropriate 0 orientation with respect to the wall.

According to a second aspect of this invention, there is provided an electrical component for use with the combination of a wall box and a connector module configured for reception in a predefined location in the wall box, the connector module defining at least one wire terminator to which an individual wire of a cable may be connected and at least one socket which faces outwardly of the wall box, which electrical component has at least one rearwardly-directed conductor pin arranged directly to connect to a socket of the connector module on offering the component to the wall box.

It will be appreciated that the electrical component of this invention differs from conventional electrical components such as single or double socket outlets, single or multiple switches and so on in that the component is provided with at least one electrical conductor pin which is directed rearwardly of the component, so as to be capable of connecting with a connector module of this invention as described above. Despite this, the component may also have conventional screw-terminators, so that the component may be used to implement a conventional wiring installation, not using connector modules of this invention. Of course, a wiring installation may use connector modules of this invention for some of the wall boxes and conventional wiring for others.

In a case where an electrical component is provided with both conductor pins for use with a connector module of this invention and also conventional screw-terminations, advantageously a removable insulating cap is provided for the pins, in order to avoid risk of inadvertent contact with the pins when the component is being used for conventional wiring. If however the component is to be used with a connector module of this invention, then the cap (or each cap, if one is provided for each pin) may be removed so as to expose the conductor pins.

This invention extends to a wall box and connector module of this invention as described above, in combination with an electrical component also of this invention and having conductor pins co-operable with the sockets of the module.

By way of example only, certain specific embodiments of connector module, wall box and electrical component of this invention will now be described in detail, reference being made to the accompanying drawings in which: Figure 1 shows an embodiment of wall box together with a connector module fitted into the wall box; Figure 2 is a perspective view showing the rear of the connector module used in Figure 1; - 9- Figure 3 is a perspective rear view of an electrical component for use with the arrangement of Figure 1; Figure 4 shows the arrangement of Figure 1 with the wires of a cable connected to the module but with a removable cover provided on the module; Figure 5 is a side view of the removable cover of Figure 4; Figure 6 shows a double wall box together with a module arranged to permit the implementation of a ring circuit; Figure 7 shows an alternative module design, intended for use with an existing wall box; Figure 8 is an isometric view, partly cut away, of a carrier within a wall box, as a part of another embodiment; Figure 9 is a plan view of an adjustable connector module, for use with the carrier of Figure 8; Figure 10 is a side view of the carrier of Figure 8 together with the module of Figure 9; and Figure 11 is a side view of an alternative connector module for use with the carrier of Figure 8.

Referring initially to Figure 1 there is shown a moulded plastics material wall box 10 having a rear wall 11, two side walls 12 and top and bottom walls go 13. The wall box has two columns 14 moulded integrally one with each side wall 12 respectively, which columns are provided with threaded bores 15 for receiving fixing screws of an electrical component to be secured to the wall box.

Further, the rear wall 11 may have an arrangement of holes (not shown) permitting the fixing of the wall box to a wall, which holes may be slotted to - 10 permit minor adjustment of the precise position of the wall box as the fixing screws are tightened.

Also shown in Figure 1 is a connector module 16, located against the rear wall 11 and right-hand side wall 12 of the wall box. The connector module is generally of cuboid shape and has a channel 17 for accommodating the column 14 on the right-hand side wall 12. Moulded integrally with the top and bottom walls 13 are resilient claws 18 behind which the front face 19 of the connector module may be located, when the module is pushed fully home against the rear wall 11.

The connector module 16 is provided with three wire terminators 21,22,23, which open through side face 24 of the module. A screw clamping arrangement is associated with each such terminator, access to the screws 25 being gained through the rear face 26 (Figure 2) of the module. Once wires 27 have been clamped to the respective wire terminators 21,22,23 by tightening of the screws 25, the module may be pressed home to the location shown in Figure 1 whereby access to the screws 25 no longer is possible.

The front face 19 of the module has three sockets 28,29,30. Each socket is electrically connected to a respective wire terminator 21,22,23, within the connector module and has conductor surfaces for completing a connection with a pin of an appropriate profile, pushed into the socket. The arrangement of the sockets should be irregular, in order to ensure only a component having an appropriate corresponding irregular arrangement of pins may connect thereto. As shown in Figure 1, each socket is of a rectangular shape; the live and neutral sockets are relatively close together with an earth socket spaced from the live and neutral sockets and also fumed through with 90 with respect thereto. Clearly, other socket shapes and arrangements may be employed so long as the arrangement of the sockets is sufficiently irregular to prevent the incorrect connection thereto of an electrical component.

In Figure 1, one of the side walls 12 is shown as having an access hole 32 for an electrical cable. That hole may be pre-moulded in the wall box, or may take the form of a knock-out piece connected to the wall box by a weakened zone. Further holes or knock-out pieces may be provided as required, though it is advantageous for the cables with which the wall box is to be used to enter the wall box from the side opposed to that at which the connector module 16 is located.

Figure 3 shows an electrical component 33 for use with the arrangement of Figure 1. This component may be a switch or a socket outlet for a power plug or almost any other electrical component conventionally employed in a wiring installation. The component includes a face plate 34 having two horizontally-opposed holes 35 for fixing screws 36, the arrangement of the holes and screws corresponding to the columns 14 of a wall box whereby the component may be secured thereto with the screws 36. Projecting from the rear of the face plate 34 are the usual elements of such a component, such as a switch mechanism or a connector block for a socket, but in the component of this embodiment, those elements are contained within a housing 37. Projecting from that housing, and connected with the housing to the elements, is an arrangement of three conductor pins 38,39,40, that arrangement corresponding to the arrangement of sockets 28,29,30 of the connector module 16. Further, - 12 the pins 38,39,40 are disposed in the appropriate lateral and vertical position with respect to the face plate 34 such that they may connect to the respective sockets 28,29,30 of a module 16 in the correct position in a wall box 10, as the face plate is offered to the wall box for securing thereto.

Though not shown in Figure 3, the component may also be provided with conventional wire terminators (not shown), so that it may be used without a connector module 16. In this case, a removable insulating cap (also not shown) may be provided for the conductor pins 38,39,40 to protect from accidental contact with those pins when the conventional wire terminators are employed.

Figure 4 shows the assembly of Figures 1 and 2, but with a cable 42 entering the wall box through access hole 32. As shown, a grommet 43 may be fitted to the hole 32, to seal the cable to the wall box and to resist damage to the outer sheath 44 of the cable. The three wires 27 of the cable 42 are cut to appropriate lengths, the insulation is stripped from the last few mm of each wire and then the wires are terminated using the screws 25 of the terminators 21,22,23. Thereafter, the module is pressed home in the wall box, to be secured by the claws 18 engaging the front face 19 of the module.

Also shown in Figures 4 and 5 is a cover 46 typically moulded from a plastics material and having pegs 47 projecting from one face, which pegs are a light press-fit in the sockets 28,29,30 of the module 16. The cover 46 serves to protect the sockets from the ingress of foreign matter (such as render or plaster applied to a wall during the finishing thereof) prior to the attachment of an electrical component 33 to the wall box. At that time, the cover may be pulled away from the module and discarded. - 1 3

Figure 6 shows an arrangement of a wall box and module similar to that of Figure 1, but configured for use with a double socket outlet and implementing a ring main circuit. The wall box 50 is provided with a plurality of knock-out pieces 51 any one or more of which may be knocked out of a side wall in order to permit the entry of an electrical cable at a convenient location. In the illustrated embodiment, only one cable 52 is shown as entering the wall box, this through the right-hand side wall of the box.

The connector module 53 has two grooves 54 formed into its rear face whereby cables may be passed between the module and the rear wall of the wall box. Cable 52 passes through the lower groove 54 in this way. In order to implement a ring main, the wires of two cables must be connected together at the module. This could be achieved by providing screwterminators as has been described above, with a relatively large hole to receive the conductors of both wires, much as is currently employed with conventional electrical components. In the alternative, and as shown in Figure 6, pairs of terminators 56,57 and 58 could be provided within the module, each pair being electrically connected together. Advantageously, for this arrangement the terminators are of a push-fit design intended to receive wires of a predefined diameter- and in the case of a UK ring main, of 2.5 mm diameter. With such terminators, the module may be fitted to the wall box prior to the connection of the wires thereto, since no access is required to the rear face of the module.

Figure 7 illustrates a conventional moulded plastics material wall box 60, together with a module 61 specifically adapted for use with a preexisting wall box. The module differs from that of Figures 1 and 2 in that it is provided with a pair of resilient claws 62,63 at its upper and lower ends, which claws are deformed inwardly as shown by arrows 64 as the module is pressed into the wall box, between the top and bottom walls 65 of the wall box. Also, the module is shown as having a pair of grooves 66 similar to those of module 53, to facilitate the implementation of this modular system with an existing wall box.

In other respects, the module 61 may correspond to that of Figures 1 and 2, or that of Figure 6 in that it is provided with push-fit wire terminators; as such it will not be described further here.

Though generally it is the aim of wall finishers to have the applied render and skim coat (plaster) only slightly proud of wall boxes fitted during first-fixing of an electrical installation, it sometimes happens that the wall box is buried deeper below the surface of the finished skim coat. In such a case, it could be that the use of a connector module as has been described above may give no contact with the conductor pins projecting from an electrical component, or may give inadequate contact possibly leading to an unsafe condition. The arrangements of Figures 8 to 11 may be employed in such a case, to ensure that adequate electrical connections may be achieved between the respective module and the conductor pins of an electrical component to be secured to the wall box.

no In Figure 8, there is shown a conventional moulded plastics wall box 70, but fitted with a U-shaped carrier 71, pressed between opposed side walls 72,73 of the wall box. As shown in Figures 8 and 10, the arms 74 and 75 of the carrier are provided with outwardly-facing barb-shaped ribs 76 which dig into the material of the wall box, so as to hold the carrier in its fitted position shown - 15 in Figure 8. On each arm 74,75 of the carrier, there is provided an inwardly directed respective rail 77.

Figures 9 and 10 show a first embodiment of adjustable connector module 78, which is generally similar to module 16 in that it includes wire terminators 21,22,23 and also sockets 28,29 and 30 for the pins of an electrical component (such as is shown in Figure 3) to be used therewith. The module includes a pair of opposed grooves 79 within which the rails 77 may be received in order to permit sliding movement of the module vertically within the carrier 71, between the side walls 72,73 thereof. The module has two bores 80 adjacent and parallel to the grooves 79, within which are received respective screws 81. Each bore is counterbored with a larger diameter from the outwardly-directed face, to permit accommodation of the screw head therewithin. A nut 82 is held captive at the other end of each bore, the screw being threadingly engaged with each nut. In this way, the position of the module 78 with respect to the base wall 83 of the carrier may be adjusted by rotating the screws 81 and so, in the event that the base wall 83 is too far recessed from the surface of the skim coat, the module may be lifted up so as still to achieve an adequate electrical connection between the sockets of the module and the connector pins of an electrical component.

The position of the screws may be preset by measuring the distance between the outwardly-directed surface 84 of the module and the exposed surface of the skim coat, with the screws fully threaded into the bores 80.

Then, the screws may be retracted by a suitable distance in order to achieve a required spacing between the surface 84 and the surface of the skim coat. - 16

Figure 11 shows a modified form of connector module for use with the carrier 71 shown in Figure 8, and again permitting adjustment of the distance between the outwardly-directed surface 84 of the module and the surface of the skim coat. This modified form of module includes two sets of downwardly projecting legs 85 arranged one set to each side of the module. The legs of each set are of different lengths, with the longest legs nearest the grooves 79.

Advantageously, the legs are moulded integrally with the material of the module and can be broken off as required (but usually in pairs) in order to give the required spacing between the outwardly-directed surface 84 of the module and 0 the surface of a skim coat.

In all other respects, the embodiments of Figures 8 to 11 are used in essentially the same manner as the previously described embodiments. As such, they will not be described in further detail here. - 1 7

Claims (26)

1. An electrical connector module for use in conjunction with a wall box in furnishing the fixed wiring of a building, which connector module comprises a body configured for reception in a predefined location in a wall box for an electrical component, the connector module defining at least one wire terminator to which an individual wire of a cable may be connected, and at least one socket which faces outwardly of the wall box when the connector module is received therein, whereby an electrical component having at least one rearwardly-directed conductor pin may connect directly to the connector module 0 on offering the component to the wall box.

2. An electrical connector module as claimed in claim 1, wherein the module has two wire terminators and two sockets electrically connected within the connector module, one to each terminator respectively.

3. An electrical connector module as claimed in claim 1, wherein the connector module has three wire terminators and three sockets electrically connected within the connector module one to each terminator, respectively.

4. An electrical connector module as claimed in claim 1, wherein the connector module has three sockets and more than three wire terminators, each socket being connected within the connector module to at least one of the terminators, respectively.

5. An electrical connector module as claimed in claim 4, wherein at least one of the terminators is commoned with another wire terminator. - 18

6. An electrical connector module as claimed in claim 5, wherein the connector module has six wire terminators arranged in three pairs of communed terminators.

7. An electrical connector module as claimed in any of the preceding claims, wherein each wire terminator is a push-fit terminator arranged to connect electrically to a wire pushed therein and to restrain removal of a wire therefrom.

8. An electrical connector module as claimed in any of the preceding claims, wherein each wire terminator includes a clamping screw arranged to 0 clamp to a conductor a wire received within the terminator.

9. An electrical connector module as claimed in any of the preceding claims, wherein the sockets are arranged irregularly on the module, whereby connection to an electrical component can be achieved only if the component has the same irregular arrangement of conductor pins and is corrected orientated with respect to the module.

10. An electrical connector module as claimed in any of the preceding claims, wherein a removable cover is provided for the sockets of the module.

11. An electrical connector module as claimed in any of the preceding claims, wherein the module is provided with means to restrain the module in a wall box, once pressed therein.

12. An electrical connector module as claimed in claim 11, wherein the restraining means comprises resilient claws arranged to engage opposed side walls of a wall box. - 1 9

13. An electrical connector module as claimed in any of the preceding claims, wherein means are provided to permit the adjustment of the position of the module within a wall box, when fitted "hereunto.

14. An electrical connector module as claimed in claim 13, wherein said means comprise one of at least two screw-threaded adjusters or at least two sets of frangible legs of different lengths.

15. An electrical connector module as claimed in claim 1 and substantially as hereinbefore described, with reference to and as illustrated in the accompanying drawings.

16. The combination of a wall box for an electrical component and a connector module as claimed in any of claims 1 to 9, wherein the wall box is profiled to define the location for the connector module.

17. The combination of claim 16, wherein the wall box is moulded from a plastics material and has wall portions moulded to define a location for the connector module.

18. The combination of claim 17, wherein the wall portions include restraining means to restrain the connector module in the wall box, once received therein in the predefined location.

19. The combination of claim 18, wherein the restraining means comprise claws moulded integrally with the wall box and which interengage with abutment faces of the connector module.

20. The combination of claim 19, wherein the claws and abutment faces together define the orientation of the connector module with respect to the wall box as well as the predefined location for the module. -

21. An electrical component for use with the combination of a wall box and a connector module configured for reception in a predefined location in the wall box, the connector module defining at least one wire terminator to which an individual wire of a cable may be connected and at least one socket which - faces outwardly of the wall box, which electrical component has at least one rearwardly-directed conductor pin arranged directly to connect to the socket of the connector module on offering the component to the wall box.

22. An electrical component as claimed in claim 21, wherein the component has two rearwardly-directed conductor pins for electrical connection to two sockets provided on the connector module.

23. An electrical component as claimed in claim 21, wherein the component has three rearwardly directed conductor pins, disposed in an irregular arrangement with respect to the profile of the component, whereby the component may connect to a connector module in only one orientation.

24. An electrical component as claimed in any of claims 21 to 23, in which there is provided a removable insulating cap for the conductor pins of the component.

25. An electrical component as claimed in any of claims 21 to 24 and which comprises one of a socket for an external plug or a switch.

26. An electrical component as claimed in any one of claims 21 to 25 together with the combination of a wall box and connector module as claimed in any one of claims 16 to 20.