The present invention relates to an electrical fitting, and in particular to an electrical fitting including a switch for altering the electrical status of the fitting. The invention is applicable to any form of switchable electrical fitting which is mounted in a wall, ceiling or floor, including switchable mains outlets, light switches, spur switches and appliance switches.

Wall-mounted electrical fittings typically include a back box recessed into the wall and the fitting itself which is provided with terminals at the rear for connection to the building wiring circuit and which has a front face with an area larger than that of the back box/recess so that the recess edges are covered up and a neat finish presented.

A problem exists when new properties are being constructed or existing properties are being rewired during a major refit. Wiring systems are usually installed by an electrician before the plasterboard is fitted to the stud work and/or the walls are plastered. This initial wiring installation is typically known as a "first fix". It is not possible to leave the electrical fittings connected and in situ after a first fit because they will obstruct the wall construction or finishing and may also become contaminated with plaster, paint or other building debris. Wth the fittings removed, wiring is usually left protruding from holes in the wall or from back boxes, and can easily become damaged or covered in building materials as the wall is finished. It is then necessary for the electrician to make a second visit to the site after the walls have been completed, in order to fit and test all the electrical fittings. At this "second fix" stage, it can be expensive to rectify any problems detected if for example sections of wall need to be removed so that a new section of cable can be installed. Also, significant cost savings would be made if a second visit by a qualified electrician could be avoided.

A solution to the above problem has been proposed in several patent publications, all generally along the same lines. GB-A-2438896 (Farnhill), GB-A-2438001 (Smith), GB-A- 2394603 (Pringle) and GB-A-2341733 (deBoeck) all generally propose the solution of a removable faceplate containing the switch, socket, etc. which is provided with electrical plug contacts on the rear which engage in electrical socket contacts of an intermediate socket unit which is mounted within the back box and connected to the building's wiring circuit. During construction, preparation or decoration of the wall in which the fitting is mounted, the faceplate is removed so that the work can take place right up to the edge of the back box and so that the faceplate is not damaged or contaminated. The present invention addresses the same problem, but in a much simpler manner.

In accordance with the invention, there is provided an electrical fitting comprising an intermediate fitting for insertion into a conventional back box mounted in a wall or other surface, the intermediate fitting having electrical terminals for connection to a wiring circuit and a primary switch on its front face which is movable between at least two positions to alter the electrical status of the intermediate fitting, and a removable faceplate which supports a secondary switch movable between at least two positions, the secondary switch mechanically engaging the primary switch when the faceplate is mounted in use adjacent the front face of the intermediate fitting, such that movement of the secondary switch causes movement of the primary switch and alteration of the electrical status of the intermediate fitting. The invention also extends to a faceplate for an electrical fitting, the electrical fitting having a primary switch which is movable between at least two positions to alter the electrical status of the fitting, the faceplate supporting a secondary switch movable between at least two positions, the secondary switch mechanically engaging the primary switch when the faceplate is mounted in use adjacent the front face of the fitting, such that movement of the secondary switch causes movement of the primary switch and alteration of the electrical status of the fitting.

The invention also extends to an intermediate electrical fitting for mounting within a conventional back box mounted in a wall or other surface, the intermediate fitting having electrical terminals for connection to a wiring circuit and a primary switch on its front face which is movable between at least two positions to alter the electrical status of the intermediate fitting, the primary switch being adapted for mechanical engagement with a secondary switch supported on a removable faceplate such that when the faceplate is mounted in use adjacent the front face of the intermediate fitting, movement of the secondary switch causes movement of the primary switch and alteration of the electrical status of the intermediate fitting.

The present invention in its various aspects avoids the need for electrical connections between the intermediate fitting and the faceplate. Through the provision of a

straightforward mechanical engagement between the primary and secondary switches, all the electrical components of the fitting can be retained within the intermediate fitting. This provides a safer, more reliable electrical fitting as a whole, which does not rely on additional electrical connections to be made as in the prior art. The construction of the faceplate is also simpler and therefore less expensive to manufacture. The intermediate fitting of the present invention can be fitted by the electrician during the "first fix" operation and, most importantly, left in situ so that no wiring is exposed. This allows the wiring and fittings to be fully tested during this time and any problems rectified before the walls are finished. Because there are no further electrical connections to be made, there does not need to be a "second fix" visit by a qualified electrician to install or test everything again; once the walls are finished, the faceplates are simply mounted in position over the back box and intermediate fitting. Provided the intermediate fitting is correctly positioned within the back box so that the spacing of its front face from the wall surface is within tolerance, the mechanical switch engagement will occur automatically and the fitting will be ready for use.

Because the intermediate fitting of the present invention in effect provides a safe, functioning electrical fitting, it may be possible to operate or use the fitting during the construction or repair stage, if safe to do so. In order to ensure that the intermediate fitting is not contaminated with building materials or debris during construction or repair of the wall, it is preferable that the intermediate fitting is mounted so as to be wholly inside the back box. In this way, the front face of the intermediate fitting is set back from the face of the wall, providing protection from debris. In addition or alternatively, a blanking plate could be provided to fit over the front face of the intermediate fitting, which would be removed when the faceplate is installed and the fitting put into service.

However, in a further development of the present invention, the electrical fitting preferably further includes a shield which projects forward of the intermediate fitting in use to provide protection from debris during construction/repair of the wall or other surface, when the faceplate is not fitted. Preferably the shield also projects forward of the wall surface to provide additional protection.

Preferably, the shield is in the form of a sleeve which surrounds the intermediate fitting. The sleeve may be rectangular or square in section. The sleeve may be open at least its inner end so that it can be pushed over the intermediate fitting and into the back box after the intermediate fitting has been installed in the back box. Alternatively, the shield or sleeve may be configured to be installed in the back box before the intermediate fitting is put in place, and the intermediate fitting can then be used to secure the shield or sleeve in position in the back box. In any form, the outer end of the sleeve is preferably closed to provide maximum protection from debris.

When the faceplate is to be fitted, it may be necessary to first remove the shield or sleeve completely. Alternatively, if the shield/sleeve projects beyond the wall surface, it may be easier to trim it so that it is flush with the wall surface, thereby enabling the fitting of the faceplate. This would be the case for the embodiment mentioned above which is installed in the back box before the intermediate fitting is installed.

The primary and secondary switches and the mechanical engagement between them are clearly important features of the invention. The primary switch on the front face of the intermediate fitting is movable between at least two positions to alter the electrical status of the fitting. "Electrical status" typically means on or off, but in other applications other states could be applicable such as high/low, bright/dim, etc. The term should not be limited to just two states either, since more than two states may be applicable depending on the circumstances, for example in the case of a three-position switch or a rotary dimmer control. The term "switch" may cover any conventional switch, including pushbutton, rocker, slider or toggle switches, but it may also cover rotary switches or controls as in the dimmer control example, which in effect "switch" the electrical output of the fitting from one status to another. While the primary switch directly controls the electrical status of the fitting, the secondary switch supported on the removable faceplate has no direct electrical control itself but acts mechanically on the primary switch so that movement of the secondary switch causes movement of the primary switch and thereby alteration of the electrical status of the fitting. Any structure or component which is able to act mechanically on and move the primary switch is considered to be a secondary "switch" because it is in effect having the function of a switch. Essentially, the secondary switch has the function of an actuator. Preferably, the secondary switch is a component which is movable relative to the faceplate and which acts mechanically on the primary switch in use to thereby alter the electrical status of the fitting. The secondary switch may be a single component or it may be formed from two or more components co-operating with one another to perform the function. It may have defined positions (e.g. it may be sprung independently of the primary switch), or its available positions may be defined by the positions of the primary switch.

In its simplest form, the secondary switch could be a movable or flexible section of the faceplate which, when pressed, acts on the primary switch. Alternatively, it may take the form of a more switch-like structure, such as the forms discussed above in relation to the primary switch. In a preferred embodiment, the secondary switch is a rocker switch.

In order to perform its function of effecting movement of the primary switch, the secondary switch must transfer its movement at the front of the faceplate to the rear of the faceplate, to the point of mechanical engagement with the primary switch. In the case where the secondary switch is a rocker switch for example, the switch may be pivotally mounted in an aperture in the faceplate with parts of the switch both at the front and the rear of the faceplate moving depending on the switch position. In the case where the secondary switch is a rotary switch, the switch may include a shaft which is mounted in the faceplate and extends through it to a coupling for engagement with the primary switch. Other arrangements will be apparent to the skilled person.

In the case where the secondary switch is a rocker switch, the primary switch may also be a rocker switch. Alternatively, the primary switch may comprise a double-button switch having the same function as a rocker switch. In either case, the secondary switch is preferably provided with projections which engage with the primary switch in use and transfer the movement. As discussed above, the present invention extends to an intermediate electrical fitting for mounting within (and preferably substantially entirely within) a conventional back box mounted in a wall or other surface. The invention also extends to a faceplate for an electrical fitting, as well as to the combination of the intermediate fitting and faceplate. The invention may further extend to the back box itself in combination with any of the other components of the fitting mentioned above. In use, the back box is preferably mounted in a recess in the wall or other surface, and is preferably flush-mounted with the wall rather than protruding from it to any extent. The invention also extends to a kit of parts comprising the intermediate fitting and faceplate, and optionally further including the back box, shield/sleeve or the blanking plate mentioned above, in any combination. The invention is applicable to any form of switchable electrical fitting which is mounted in a wall, ceiling or floor, including switchable mains outlets, light switches, spur switches and appliance switches. When the intermediate fitting is an electrical socket, the faceplate preferably includes one or more apertures corresponding to the apertures of the socket.

An embodiment of the invention will now be described by way of example only and with reference to the accompanying drawings, in which:

Fig. 1 shows a perspective view of the faceplate, intermediate fitting, sleeve and back box of an embodiment of the invention;

Fig. 2 shows a perspective view of the back box and intermediate fitting in accordance with the present invention, with the sleeve omitted for clarity; Fig. 3 shows a perspective view of the rear side of the faceplate;

Fig. 4 shows a side view of the faceplate immediately prior to being fitted;

Fig. 5 shows an underneath perspective view of the intermediate fitting showing the wiring circuit electrical terminals; and

Fig. 6 shows a perspective view of the blanking plate, intermediate fitting, sleeve and back box of the invention. Fig. 1 shows an embodiment of the invention, comprising a back box 1 , sleeve 3, intermediate electrical fitting 4 and faceplate 21. Back box 1 is a standard electrical fitting back box which typically comprises a square or rectangular rear panel and four forward- projecting sides. Two electrical fitting screw mounts 2 are also provided. Back box 1 is usually made from either plastic or metal, and is designed to be inserted in an

appropriately-sized recess in the wall or other surface in which the electrical fitting is to be mounted.

Sleeve 3 is of rectangular cross-section and in this embodiment is open at both ends. It is sized so as to be insertable into back box 1 , but is deeper than back box 1 so as to project forwardly from it in use so that the intermediate electrical fitting 4 is protected from debris during plastering, painting and finishing of the wall surface. Ideally, sleeve 3 is made from a plastics material such as polypropylene. The sleeve 3 may also comprises several series of perforations which allow the sleeve to be cut off at an appropriate length after completion of the building or decorating work and before the faceplate 21 is fitted. Intermediate electrical fitting 4 in this embodiment comprises a dual mains outlet comprising two three-pin socket outlets 15. The sectional area of the fitting 5 is sized so as to fit within that of the back box 1 , and the fitting 4 is secured in back box 1 by means of captive screws (not shown) in screw holes 6. Further screw holes 7 are also provided for screws (not shown) to mount the faceplate 21. Because the back box 1 is standard, the spacing between screw holes 6 will also need to be standard, but it can be seen that unlike a conventional electrical fitting, intermediate fitting 4 does not have a wider flange on its front face. Intermediate fitting 4 fits inside sleeve 3 as well as inside back box 1 , and when fitting 4 is secured in place by the screws, sleeve 3 is also secured in place. Projections 14 allow the intermediate fitting to be installed flush against a wall without risk of overtightening of screws. Part of the back 10 of the intermediate fitting 4 is shaped to allow access for installing wires, which can be seen more clearly in Fig. 5 described below. Intermediate fitting 4 is provided with a primary switch 5 for each socket 15. Primary switch 5 switches its respective socket on or off as appropriate. Each switch 5 comprises an "on" button 20b and an "off" button 20a with the effective function of a rocker switch, in that pressing one button causes the other button to be released. Faceplate 21 presents the appearance from the front of a conventional twin-socket mains outlet. It is provided with two screw-mounting holes 17 and two sets of socket apertures 16 corresponding to the socket apertures of the three-pin sockets 15 in the intermediate fitting 4. It is also provided with further screw holes 8 corresponding to the screw holes 7 in the intermediate electrical fitting 4, for mounting the faceplate 21. Faceplate 21 is also provided with two secondary switches 9, described in more detail below. Secondary switches 9 are in effect captive actuators which mechanically engage with primary switches 5 to enable the appropriate socket to be switched on or off.

Fig. 2 shows a perspective view of the back box 1 and intermediate fitting 4, with the sleeve 3 omitted for clarity. Buttons 20a and 20b of each primary switch 5 can be seen more clearly in this view. Fig. 3 shows a perspective view of the rear side of faceplate 21 , showing the rear faces of secondary switches 9 in more detail. Each secondary switch 9 is a captive rocker mounted in faceplate 21 and is provided with two projections 1 1a, 1 1 b on its rear surface. Each projection 1 1a, 1 1 b is designed to engage with a button 20a or 20b of the corresponding primary switch 5 so that movement of a secondary switch 9 from one position to the other causes one button of the primary switch 5 to be pressed and the other button to be released. Fig. 4 shows a side view of the faceplate 21 immediately prior to being fitted to the intermediate fitting 4, showing more clearly the method of engagement between the projections 11 a, 11 b of the secondary switches and the buttons 20a, 20b of the primary switches 33. Fig. 5 shows an underneath perspective view of the intermediate fitting 4, showing the wiring circuit electrical terminals, each comprising a cable clamp 24, 25, 26 and a clamping screw 12, 22, 23. Fitting 4 is also provided with an earthing bar 27 as well as a recess 39 for a double-threaded depth-adjusting mounting. The projections 14 and shape 10 of the rear of the intermediate fitting, allowing for easy access for wiring, can also be seen 10.

Fig. 6 shows a perspective view similar to Fig. 1 , but with the faceplate 21 replaced by a temporary cover plate or blanking plate 13, still having screw holes 18, 19. Blanking plate 13 can be used to provide protection for the intermediate fitting 4 from paint or other building materials, for example when a room is being re-decorated after the initial electrical installation.