Electrical assembly and components therefor

Abstract

An electrical fitting comprises a wall housing 50 defining a chamber having a side wall and a base wall (figure 8, 62) of non-conductive material. The base wall comprises a plurality of openings (figu

Description

TECHNICAL FIELD The present invention relates to an electrical assembly and to components for such an assembly, and in particular a wall mounted assembly for a power socket, a light switch or any other mains powered device, as well as to individual parts of such an assembly. The preferred embodiments are able significantly to speed up of the instalment of in-wall electric components such as sockets or switches into receptacles or housings that can also be continuously electrically powered during the installation process. BACKGROUND TO THE INVENTION It has been common place for many decades to provide in buildings such as offices, private dwellings, hospitals, schools and so on with electrical fittings or outlets, which are generally preferably installed into a wall recess to provide a substantially flush fitting with the surface of the wall. The fittings can also be surface mounted, which tends to facilitate installation but provides a less secure and more unsightly arrangement. Whereas traditionally such electrical fittings may have been single or double fittings, such as a single or a double mains power socket, with the increasing provision of electrical and electronic devices it is becoming increasingly necessary to provide a bank of multiple electrical fittings in proximity to one another. Doing so provides a much more secure power supply compared to, for example, a multiple gangway extension, which not only can be unsafe but is also often unsuitable for some modem electrical equipment. Electrical power of this nature is typically provided to a wall location by any of well-known assemblies, which typically include a box or housing, usually made of plastics or other material and fitted into a wall aperture or recess (or surface mounted). An electrical fitting plate, which includes electrical terminals to be coupled to electrical wiring and a front element which may be a power socket plate, electrical switch or any other such component, is then attached to the housing. Typically, in an installation, an electrician will provide mains wiring (live, neutral and earth) to the embedded housing by an appropriate wire and will then attach the wires to the connectors and the support plate, before fitting the final component (e.g. power socket, light switch and the like). All of this must be done with the mains power disconnected so as to protect from inadvertent electrical shocks during process of installation. When multiple electrical elements are to be provided, for example in a bank, it is necessary to provide electrical wiring to each electrical element, the wiring coupled in parallel to ensure individual and continued operation at each electrical fitting. An example is shown in Figures 1 and 2 of the accompanying drawings. With reference to Figure 1, there can be seen a surface of a wall 10 having five apertures or recesses 12 therein, each for receiving a respective electrical fitting. Within each aperture 12 there is provided a housing 14, often called a back box, which in this example is a plastics element which can be either embedded into a wall 10 at the point of construction of the wall or fitted after, once an aperture 12 has been created. These housings are well-known in the art. Figure 2 shows a bank of four such housings 14 disposed in side-by-side relation. In order to provide power to each electrical fitting 20, a mains cable 22, to be coupled to a mains electricity supply is fed into a hole 24 either pre-formed or punched into a housing 14. For the next housings 14 in the sequence, further sets of electrical wires 26-28 are fitted between adjacent housings 14, as will be readily apparent at least in Figure 2. Save for the last fitting in the sequence, each electrical fitting 20, will typically have two wire terminals of each type - live, neutral and earth - to complete the parallel electrical connection. It is therefore necessary for an electrician to fix, in this example, six wires to each set of electrical terminals of a mounting element 30, as will be apparent in Figures 1 and 2. Only once each electrical fitting 20 has been wired and the mounting elements 30 are put in place and assembled as necessary can the assembly be deemed safe to connect to mains power. It is therefore only at the fully assembled stage that the electrical fittings can be tested to see whether they have been wired correctly and are operational. Given the number of wires and number of operations that need to be carried out by the electrician, it is not infrequent that once the electrical installation has been completed it is discovered that there are faults. These may be discovered immediately or after a short period of use, particularly if some of the wires are loose within the fitting. This requires an electrician to return to the premises to test the electrical fittings to find and repair the fault. Often, this takes some investigation as it is not always immediately apparent where the fault lies. The skilled person will know that this is time consuming and expensive. As an example, it is not uncommon in a modern small to medium sized apartment for there to be of 40-50 sockets spread throughout the apartment and often in a series of banks for powering and controlling interconnected electrical equipment. In a situation of the type depicted in Figures 1 and 2, it can easily take about around a quarter of an hour to fit each electrical fitting, so the cost can rapidly become significant, as is the cost of locating and carrying out any postinstallation repairs. There have been some proposals in patent literature to address some of these problems, for example in EP-2,497,173 and WO-2011 / 05452. However, these solutions do not address all of the problems encountered in the art or the requirements of the industry. The applicant also proposed an earlier assembly in WO-2021 / 164839. SUMMARY OF THE PRESENT INVENTION The present invention seeks to provide an improved electrical fitting and electrical connector. According to an aspect of the present invention, there is provided an electrical fitting comprising a wall housing, which housing has a front and includes a chamber having a side wall and a base wall of non-conductive material, the chamber being shaped and sized to receive an electrical socket or switch face plate; the chamber base wall having a first side facing the chamber and a second side opposite the first side, the base wall having a plurality of openings therein; a conductive element support disposed at the second side of the base wall and electrically insulated from the chamber; a plurality of conductive elements attached to the support and extending across a lateral extent of the support in a power bus arrangement, each conductive element being aligned with a respective aperture in the base wall and being spaced from the first side of the base wall and below a plane of the base wall, so as to prevent electrical contact with the conductive elements at the surface of the first side of the base wall; the support including first terminal portion extending beyond a lateral periphery of the housing, at least one of the conductive elements extending into the first terminal portion, and wherein the first terminal portion has an exposed face facing the front of the housing; a second terminal portion located within a lateral periphery of the housing; wherein said at least one of the conductive elements extends into the second terminal portion; wherein the first and the second terminal portions have complementary coupling features, and wherein the second terminal portion has an exposed face facing a rear of the housing; the conductive elements forming a power bus behind the base wall, the power bus extending to the first and second terminal portions such that when two of said fittings are connected together with the first terminal portion of a first of said fittings connected to the second terminal portion of a second of said fittings the conductive elements of the first and second of said fittings connect to one another in a connected power bus arrangement, wherein the first and second of said fittings are able to be connected together by a front-to-rear sliding motion and in an electrically powered-up arrangement in which the housing chamber of each said fitting is electrically insulated from the conductive elements prior to fitting of an electrical socket or switch face plate. The housing is preferably of a type that is fitted into a recess or cavity of a wall and acts to hold a face plate of a socket, in the manner similar to a standard solid wall box or dry lining wall box, although having the features and advantages taught herein. Advantageously, the housing is made of non-conductive material. The housing and the support are in the form of an assembly, although in other embodiments they may be formed integrally with one another. In the preferred embodiments, the apertures are in the form of parallel slots in the base wall. They are most preferably oriented orthogonal to the conductive elements, in practice to extends upwards along a wall, such that the socket or switch face plate can be adjusted vertically relative to the housing. It is to be understood that the housing is sized and shaped for a socket or switch face plate but can be used with many other electrical front components including for example sensors, timers and any other electrical component to be powered. Advantageously, each conductive element includes a terminal facing and spaced from the associated aperture and each terminal preferably extends across a part of an area of the associated aperture. In the preferred embodiment, the conductive elements are strips of metal or metallic material. The fitting preferably also comprises an electrical connector having a plurality of electrical terminals extending therefrom, wherein the electrical terminals are in the form of fin or blade elements and are disposed so as to be insertable into respective apertures in the base wall of the housing. Advantageously, each electrical terminal of the electrical connector is smaller than its respective aperture in the base wall in at least one dimension. This allows the connector to the moved relative to the housing, in the preferred embodiment upwards or downwards on a wall, for alignment purposes. In some embodiments, the electrical connector is an adapter for an electrical unit of the fitting. For this purpose, the electrical connector may comprise a plurality of connection terminals each electrically coupled to a respective fin or blade element. In other embodiments, the electrical connector is formed integrally with an electrical unit of the fitting. The electrical unit may be a power socket, light switch or sensor, or other electrically powered electrical component. Advantageously, the electrical unit is a CEE-7 compatible socket; or a socket meeting the DIN 49073, DIN 49445, DIN 49447 or DIN EN 60309-2 standards. There is also described an electrical connector comprising a plurality of electrical terminals extending therefrom, wherein the electrical terminals are in the form of fin or blade elements disposed substantially parallel to and spaced from one another, the connector being insertable into a chamber of an electrical housing, the chamber having a base wall of non-conductive material and having a plurality of substantially parallel slots therein, a plurality of conductive elements in a power bus arrangement disposed at a side remote of the chamber and spaced from the base wall, wherein the blades or fins are insertable into the slots so as to couple electrically the connector to the conductive elements. Preferably, the blades or finds are of substantially the same dimensions as one another. In some embodiments, the electrical connector is an adapter for an electrical unit. The electrical connector may comprise a plurality of connection terminals each electrically coupled to a respective fin or blade element. In other embodiments, the electrical connector is formed integrally with an electrical unit. The electrical unit may be a power socket, light switch or sensor, or other electrically powered electrical component, advantageously a CEE-7 compatible socket; or any socket meeting the DIN 49073, DIN 49445, DIN 49447 or DIN EN 60309-2 standards. The arrangement of the electrical elements is such that even when powered a person is protected from accidental electrocution. Additionally, the arrangement provides an uncluttered assembly and particular chamber for receiving an electrical unit, such as a power socket and so on. The electrical connector has a configuration which enables the connector to be adjustable in what could be described as a vertical direction (parallel to the fin or blade elements) while ensuring continued good electrical coupling to an electrical fitting, therefore allowing for adjustment of the position of any electrical device formed with or coupled to the electrical connector. The preferred embodiments disclosed herein provide an assembly which avoids and / or minimises the problems encountered in the art. They are able to provide a bank of electrical fittings which do not need wiring between each fitting, as in the prior art, which avoid the need for wiring each electrical fitting individually, and which provide a mechanism by which electrical fitting can be tested prior to final installation. They can also provide an easy way to add an existing electrical installation to provide more power outlets. The assembly can also include well-known and commonplace mounting elements, such as the de facto standard CEE-7 compatible socket, or any socket meeting the DIN 49073, DIN 49445, DIN 49447 or DIN EN 60309-2 standards. The preferred embodiments can provide an assembly that can receive any standardised end element in an electrical installation. They can also enable adjustment of the end element, particularly in a vertical or transverse direction of the installation, as well as allowing the assembly to be safely powered even during the course of installation The applicant believes that a system of the type disclosed herein can significantly speed up the time for installation of such electrical fittings, can significantly reduce fitting errors, and also provides a much more secure electrical fitting than prior art systems. Other aspects and advantages of the teachings herein would become apparent to a person skilled in the art from the description that follows. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the present invention are described below, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a schematic diagram of an example of bank of conventional electrical fittings in the process of being installed, in accordance with the prior art; Figure 2 is an example of the conventional electrical components of the bank of Figure 1 as they would be arranged in side-by-side relation in a wall and in the progress of being wired, in accordance with the prior art; Figure 3 is a perspective schematic diagram of a first part of a housing in accordance with a preferred embodiment of a present invention; Figure 4 is a perspective view of a second part of the housing of the embodiment of Figure 3; Figure 5 is a perspective view from behind of the assembly of housing components of Figures 3 and 4; Figure 6 is a schematic diagram of a plurality of housings according to Figure 5 as they would be coupled to one another to form a bank of electrical fittings; Figure 7 is a partially see-through schematic diagram of the assembly of Figure 5 showing further components within the assembly; Figure 8 is a plan view of a pair of housings for Figure 5 coupled together; Figure 9 is a schematic diagram of an end component unit that would be fitted to an end fitting of a bank of electrical fittings; Figure 10 is a perspective view from above of a bank of housings to which an electrical connector plate is in the process of being fitted; Figure 11 is a schematic diagram of an electrical fitting and adaptor in accordance with a preferred embodiment disclosed herein; Figure 12 is a perspective view of a preferred embodiment of electrical adaptor according to the teachings herein; Figure 13 is a perspective view of an electrical connector plate coupled to an adaptor, according to an embodiment of the present invention; Figure 14 is a schematic diagram of an embodiment of electrical connector plate having an adaptor formed integrally therewith. It is to be understood that the drawings are schematic only and not shown to scale. It is also to be understood that at least some of the drawings omit certain standard details for the sake of clarity, as will be apparent to a person skilled in the art. DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments and concepts disclosed herein provide an assembly which is intended substantially to facilitate the fitting of electrical power units, such as sockets and the like, within a building, particularly in banks of two or more electrical units, as is becoming more common in most utilised dwellings. The preferred embodiments also provide an assembly which enables testing of the electrical units during the fitting process and before final assembly of the front component, for example the power socket, light switch and so on. Faults can therefore be detected prior to final fitting, potentially significantly speeding up the process and reducing wastage in post-fitting repairs. The preferred embodiments also provide an assembly which can be used with standard electrical power units, particularly the widespread CEE-7 compatible sockets, or any socket meeting the DIN 49073, DIN 49445, DIN 49447 or DIN EN 60309-2 standards. Referring first to Figure 3, this shows a perspective view of a first part 50 of a housing, or back box, that is intended to be embedded into a wall, similar to the traditional type housing shown in Figures 1 and 2. The first housing part 50 is typically of round cylindrical form to fit within round apertures within a wall, consistent with the known art. The first housing part 50 preferably includes a plurality of side extending tabs 52, designed to abut against a wall surface to prevent the housing part 50 from being pushed too far into the wall. There are also provided opposing guide recesses 54 on the outer surface of the housing part 50, into which there are located adjustable tab elements (not shown in Figure 3), the position of which can be adjusted by a suitable screw made to pass through apertures 56. The adjustable tabs are typically used when fitting the housing 50 to a panel of a cavity wall As is also common in the art, the first housing portion 50 is also provided with one or more bores 60 for receiving screws used for fixing an electrical unit to the housing part 50, described in further detail below. The first housing part 50 also includes a base wall 62 which preferably extends perpendicular to the cyIindrical / longitudinal axis of the housing 50. The base wall 62 is provided, in this embodiment, with three parallel slots 64, 66, 68, which in this embodiment extend almost from one side to the other of the housing 50, that is for most of the diameter of the base 62. The first housing part 50 is preferably made of an insulating material, typically a plastics material, as is commonplace in the art. This ensures that there is no electrical conduction through the material of the first housing part 50. It is not excluded that at least a portion of the housing part 50 might be made of conductive material, metal for example, for rigidity for example, but at least the sections of the base wall 62 adjacent the slots 64-68 is preferably made of or covered by electrically insulating material. Referring now to Figure 4, this shoes a perspective view of a second housing part 70 of the housing or back box of the assembly of the preferred embodiment. The second housing part 70 has a generally round upper surface 72, which in practice is coupled to and locks to the underside of the first housing part 50. For this purpose, the upper surface 72 of the second housing part 70 is provided, in this example, with four diametrically opposed lug slots 74 which coupled to lugs 76 at the bottom surface of the first housing part 50, of which one can be seen in the perspective view of Figure 5. The lugs 76 therefore couple the first and second housing parts 50 / 70 to one another to form the complete housing, or back box. The second housing part 70 includes a pair of diametrically opposed guide recesses 78, which in practice align with the guide recesses 54 of the first housing part 50, thereby to provide elongated guide recesses for the adjustable flanges, as will be apparent from the perspective view of Figure 5. Disposed in this example orthogonally to the guide recesses 78 are first and second connector portions 80, 82, which are formed integrally with the second housing part 70. The first connector portion 82 extends beyond the circumferential perimeter of the upper surface 72 of the second housing part 70 (as well as of the first housing part 50 as will be apparent from the disclosure that follows) and includes, in this example, three recesses or receptacles 90, 92, 94, separated by two dividing walls 96. Extending from each wall 96 is a rib or guide 98 which extends along a base wall 100 of the second housing part 70. The ribs 98 may be provided with laterally extending bosses or knuckles 100, for the purposes of holding an electrical connector therein by a friction or force fit, as described in further detail below. Extending parallel to the ribs 98 are preferably also further ribs 102, of which only one is visible in Figure 4. The ribs 102 are also preferably provided with bosses or knuckles 100 similar to the ribs 98. The ribs 98,102 extend to a wall 110 at an end of the second housing portion 70 opposite the first connector portion 80. The wall 100 and a peripheral portion of the second housing part 70 are spaced from one another, as will be apparent from Figure 4, to provide a slot or opening 114 therebetween. The purpose and function of the connector portions 80 and 82 will become apparent from the description that follows. The second housing part 70 is preferably also made of an insulating material, such as a plastics material. It my be made of the same material as the first housing part 50, or of a different material. When the two housing parts 50, 70 are connected together, as can be seen in the perspective view of Figure 5, they form an unitary housing or back box. In this embodiment, the first connector portion 80 extends beyond the cylindrical perimeter of the two housing portions 50, 70, whereas the second connector portion 82 is located within the cylindrical perimeter. The advantage of this arrangement is that it enables further housings (50 / 70) to be coupled to one another in what could be described as a front-to-rear sliding motion, which can substantially facilitate the fitting of a bank of housings within a hole or recess in a wall. Figure 6 shows five housings, or back boxes, arranged in a line prior to being connected to one another. It will be appreciated that once the right-most housing has been fitted into a recess of a wall, the next housing in sequence can be slid alongside the first housing until the second connector portion 82 of the second housing slots into an engages with the first connector portion 80 of the first housing, by a simple sliding motion. In order to facilitate the coupling of two or more housings to one another, there is preferably provided an engagement mechanism. In this example and with reference again to Figure 3, the engagement mechanism comprises a dovetail connector 120 at one side of the housing and a dovetail recess 122 at the opposing side. It will be apparent that when two housings are fitted together, the dovetail connectors and recesses 120, 122 inter-engage to create a solid connection of the two housings to one another. This, added to the mechanical coupling of the respective first and second connector portions 80, 82 of the two housings will provide a secure connection of the housings. This can be seen in the perspective view of Figure 8. The housing or back box formed by the housing parts 50 / 70 is also designed to obviate the need to use electrical wires to wire the electrical units which are subsequently fitted into the housings, contrary to the prior art. Referring now to Figure 7, this shows a perspective view from above of the assembly of Figure 5 but in which the second housing part 70 is shown in ghost or outline view in order to be able to discern the electrical elements held therein. For the sake of completeness, the image of Figure 7 shows an adjustable flange 130 fitted to a screw 132, which slides within the guide recesses 54, 78, in the manner described above. Located within the second housing part 70 and extending from the recesses 90-94 of the first connector element 80, along the channels between the ribs 98, 102 of the base, to the second connector element 82, are three metal strips 150, 152, 154, in the preferred embodiment made of copper or similar material. The strips 150-154 include at one end a series of spring-loaded clips 140 which are disposed within the space between wall 110 and the outer wall of the second connector portion 52, as specifically within the slot 114. There is preferably provided on the underside of the first housing portion 50 a plurality of bosses 142 for supporting the strips 150-154 particularly at the location of the -loaded clips 140, so as to ensure that these do not deflect along the longitudinal (cylindrical) axis of the assembly 50 / 70 when the clips 140 are being engaged with another electrical element, as described below. The other end of the strips 150, 154 terminate within the apertures 90-94 of the first connector element 80, in what could be described as upright extending fingers 160. These fingers are preferably also supported in the longitudinal directions so they do not deflect during the process of engagement. With reference to Figures 6 and 7 together, when two adjacent housings are to be coupled to one another, as the second housing is slid longitudinally with respect to the first housing, the fingers 160 will eventually reach to and slide into the sprung clips 140 of the second housing such that the two sets of strips 150-154 of the two housings connect together to make a common electrical path between the two housings. It could be said that the two sets of strips 150-154 form together a common electrical bus. Each electrical strip 150-154 is provided on its other side (in what could be called their upper side, with a sprung clip 170, 172, 174). Each sprung clip 170-174 is electrically connected to its respective strip 150-154, typically by soldering / welding or the like. Any suitable engagement mechanism could be used, as is the case with the clips 140-144. The sprung clips 170-174 extend in what could be described as an upward or front facing direction and in particular towards the slots 64-68 in the base wall 62 of the first housing portion 50. The sprung connectors 170-174 are used to provide electrical coupling to an electrical unit of the electrical assembly, described below. The sprung clips 170-174 are preferably disposed below the plane of the base 62 of the first housing element 50 and preferably by a sufficient that they cannot be touched by a human finger. As a result, even when electrical power is provided to the strips 150-154 the assembly, for example as seen in Figure 8, remains safe. In practice, this enables an assembly of one or more housings to be powered up even prior to final fitting. In fact the assembly can remain powered up at this point. Furthermore, it also enables the first housing to be powered up prior to coupling of a second or subsequent housings to the first, for the reason that the conductive elements within the housings remain embedded within the plastic structure of the housings, out of harms way. While the assembly taught herein is much more robust compared to prior art assemblies requiring wiring, it still enables the bank of electrical fittings to be tested at any point in time. Referring now to Figure 9, there is shown an end component 200 designed to fit onto the first housing in a bank of electrical fittings or even to a singular housing unit. It is to be appreciated that this is only an embodiment of the present invention. The end fitting 200 comprises an electrical component 202 and an end cap 204, preferably made of insulating material (such as plastics). The electrical component 202 includes, in this embodiment, a wire receptacle unit 204, which can be of any conventional form and designed to receive the bare wires of an electrical cable similar to the cable 22 shown in example of Figure 2. The fitting 202 can be of a type well known in the art, such as a terminal block or strip or other known form of cable connector, and therefore need not be described any further. Coupled to the fitting 202 is preferably a series of fingers or flanges similar to the flanges 160 shown in Figure 7 and which can fit into the sprung clips 140 of the second connector portion 80 of the first-most housing. The fitting 202 enables the provision and use of housings of a standard form of design, irrespective of the position of the housing in a bank of housing units, and also whether or not the housing units are used singularly. In other embodiments, a first of the housing units could include integral therewith a cable connector unit. The end cap 204 may be a separate component as shown and could equally be attached to the end fitting 202, and is preferably made of an insulating material, such as plastics, and preferably attaches to the end fitting 202 or the housing portion 70, such as in a push or snap fit. Referring back to Figure 6, there may also be provided a plastics cap element 206 that can fit within the top of the first connector portion 80 of the last housing in the series, thereby to hide and insulate the fingers 140 of that housing unit. Referring now to Figure 10, this shows a perspective view from above, or from the front, of a series of four housings connected together, in similar manner to that shown in Figure 8 and as will be apparent from Figure 6. As a consequence of the way in which they engage together, the housings form a unitary and secure, singular, structure. An electrical unit 300 can be fitted to each housing in a manner that is in general terms conventional in the art. At the front of each of electrical unit there can be a separable to integral face plate of a type known to the skilled person. Additionally, as will be apparent from Figure 8, there are no wires located within the chamber of the first housing parts 50. The electrical supply is entirely provided by the strips 150-154 of the housing units and these are all electrically connected together in series and disposed below the level of the base wall 62 of each first housing part 50. The configuration is therefore such that the chamber of each first housing part 50 is free of encumbrances. In order to provide the electrical connection from the electrical power bus formed by the strips 150-154 to the electrical fitting, the electrical fitting is either provided with or coupled to a series of conductive fins, as described below. With reference first to Figure 11, this shows a standard CEE-7 compatible socket 320 and an adapter unit 330 (and could equally be any socket meeting the DIN 49073, DIN 49445, DIN 49447 or DIN EN 60309-2 standards). The adapter unit, shown in better detail in Figure 12, includes a base element 332, made of non-conductive material, to which are fitted three thin elements which in this embodiment substantially rectangular in shape, extend in what could be described as a downward direction, spaced apart from and parallel to one another. They are spaced by the same spacing between the slots 64-68 in the base wall of the first housing portion 50. In this example, integral with each fin 334-338 there is an arm 340, 342, 344 that extends around the base element 332 and is bent over and to extend parallel to the base element 332 to provide what could be described as three fingers 350, 352, 354. The fingers are, in this example, spaced from the base element 332. In practice, the fingers are sized and arranged to fit into the electrical terminals 360, 362, 364 of the electrical unit 320 and can be secured by whatever mechanism is provided in the socket element 320 (automatically if this is by a sprung electrical component or by tightening a screw, for example). The adapter 330 can therefore be fitted to a standard electrical unit, such as a CEE-7 compatible socket, or any socket meeting the DIN 49073, DIN 49445, DIN 49447 or DIN EN 60309-2 standards for example, to convert it into a form suitable for the assembly disclosed herein. Referring now to Figure 13, this shows the components of Figures 11 and 12 in an assembled form. It is to be understood that Figure 13 does not show the plastic face plate 380 of the socket, for the sake of clarity. The adapter 330 has been fitted to the electrical socket such that the fingers 350-354 fit within the respective electrical attachments of the socket. For this purpose, the fingers 350-354 could be made of a resilient material or otherwise able to be moved or deflected, depending on the position of the electrical terminals of the socket. Considering Figure 13 and Figure 10 together, it will be appreciated that all that is required to make the electrical connection of the electrical socket 322 the power bus formed by the strips 150-154 is simply to slot the electrical socket and adapter into the respective housing, whereupon the fins 334-338 will slide into their respective slots 64-68 in the base wall 62 of the front housing portion 50 and eventually make electrical connection with the sprung electrical clips 170-174 on the upper or front face of the strips 150-154. The making of that electrical connection is secure and safe because it is made in effect behind and inside the assembly, such that the fitter is at no stage exposed to live electrical current. It is therefore possible to fit the electrical connector plate and indeed the electrical socket while the bank of housing units is already powered up, should that be desired. Each electrical socket can therefore be tested at the time it is fitted. Referring now to Figure 14, there is shown another embodiment of socket 400, in which there is no separate adapter element, the fins 334-338 being formed integrally with the socket. This arrangement avoids the need to have and fit an adapter to an existing socket type, but evidently requires a socket specific to the assembly disclosed herein. It is preferred that the fins 334-338 are shorter in the transverse direction than the length of the slots 64-68. This enables the electrical unit and face plate to be moved relative to the housing, for example for alignment purposes on a wall. It will be appreciated that the disclosure herein provides a housing or back box that can safely receive and level any standardised component (such as switches, sockets, sensors etc) while being fully electrified during the installation, via the use of what could be described as a double floor housing unit, and an adapter. The double floor insulates the user and the construction from the conducting rails within the double floor. The vertical parallel slots in the user-facing base wall receive three fins or blades which make contact with the conducting rails behind the slots. The blades are preferably shorter in their 14 1024 longitudinal length than the slots, so the blades are able to move vertically within the slots while maintaining contact with the conducting rails. The conducting rails are configured with elements that extend up to the sides of the blades and apply pressure to said blades to maintain good electrical 5 contact. The adapter preferably comprises three blades positioned in parallel with a spacing, filled with an electrically insulating material, that allows them to conveniently fit within the slots in the double floor and move in the slots vertically but not laterally, The main advantages include: 10 (a) safety and speed of installation; (b) installation is a lot faster compared to individually wired installations and widely spread, standardised elements; (c) installation can be done with the housings already powered up, eliminating the testing phase of a traditional wired installation method, where most 15 problems crop up only when the power is finally turned on in the system; (d) installation can be done by unskilled workers as it does not require licensed electricians since no live conduits are exposed. It will be appreciated that described above are only embodiments of the present invention and the skilled person will appreciate that modifications may be 20 made to the described embodiments in a manner to be evident to the skilled person. The disclosure in the Abstract accompanying this application is incorporated by reference.

Claims

1. An electrical fitting comprising a wall housing, which housing has a front and includes a chamber having a side wall and a base wall of non-conductive material, the chamber being shaped and sized to receive an electrical socket or switch face plate;the chamber base wall having a first side facing the chamber and a second side opposite the first side, the base wall having a plurality of openings therein;a conductive element support disposed at the second side of the base wall and electrically insulated from the chamber;a plurality of conductive elements attached to the support and extending across a lateral extent of the support in a power bus arrangement, each conductive element being aligned with a respective aperture in the base wall and being spaced from the first side of the base wall and below a plane of the base wall, so as to prevent electrical contact with the conductive elements at the surface of the first side of the base wall;the support including first terminal portion extending beyond a lateral periphery of the housing, at least one of the conductive elements extending into the first terminal portion, and wherein the first terminal portion has an exposed face facing the front of the housing; a second terminal portion located within a lateral periphery of the housing; wherein said at least one of the conductive elements extends into the second terminal portion; wherein the first and the second terminal portions have complementary coupling features, and wherein the second terminal portion has an exposed face facing a rear of the housing; the conductive elements forming a power bus behind the base wall, the power bus extending to the first and second terminal portions such that when two of said fittings are connected together with the first terminal portion of a first of said fittings connected to the second terminal portion of a second of said fittings the conductive elements of the first and second of said fittings connect to one another in a connected power bus arrangement, wherein the first and second of saidfittings are able to be connected together by a front-to-rear sliding motion and in an electrically powered-up arrangement in which the housing chamber of each said fitting is electrically insulated from the conductive elements prior to fitting of an electrical socket or switch face plate.

2. An electrical fitting according to claim 1, wherein the housing comprises a mechanical connector configured to couple the housing at front and back sides of the housing to a complementary connector of a second similar fitting such that the fittings form a unitary body when the second fitting is electrically connected to the first fitting in an electrically powered-up arrangement by the terminal portion.

3. An electrical fitting according to claim 3, wherein the mechanical connector is a dovetail connector or dovetail recess.

4. An electrical fitting according to any preceding claim, wherein the apertures are in the form of parallel slots in the base wall, and the slots are oriented orthogonal to the conductive elements.

5. An electrical fitting according to any preceding claim, wherein the housing is made of non-conductive material.

6. An electrical fitting according to any preceding claim, wherein the housing and the support are in the form of an assembly.

7. An electrical fitting according to any preceding claim, wherein eachconductive element includes a terminal facing and spaced from the associated aperture.

8. An electrical fitting according to claim 7, wherein each terminal extends across a part of an area of the associated aperture.

9. An electrical fitting according to any preceding claim, wherein the conductive elements are strips of metal or metallic material.

10. An electrical fitting according to any preceding claim, comprising an electrical connector having a plurality of electrical terminals extending therefrom, wherein the electrical terminals are in the form of fin or blade elements and are disposed so as to be insertable into respective apertures in the base wall of the housing to couple electrically to the power bus.

11. An electrical fitting according to claim 10, wherein each electrical terminal of the electrical connector is smaller than its respective aperture in the base wall in at least one dimension.

12. An electrical fitting according to claim 10 or 11, wherein the electrical connector is an adapter for an electrical unit of the fitting.

13. An electrical fitting according to claim 12, wherein the electrical connector comprises a plurality of connection terminals each electrically coupled to a respective fin or blade element.

14. An electrical fitting according to claim 10 or 11, wherein the electrical connector is formed integrally with an electrical unit of the fitting.

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