Power supply coupling and face plate for such a power supply coupling

Abstract

A power supply coupling for location in a back box of an electrical device, wherein the power supply coupling comprises a plurality of terminals configured to connect to an electrical power supply and a plurality of electrical coupling elements, the power supply coupling further comprising a plurality of conductive paths between the plurality of terminals and respective ones of the plurality of electrical coupling elements.

Description

[0001] POWER SUPPLY COUPLING AND FACE PLATE FOR SUCH A POWER

[0002] SUPPLY COUPLING

[0003] FIELD

[0004] The present invention relates to a system and apparatus for electrical fittings.

[0005] BACKGROUND

[0006] The design and installation of electrical fittings such as plug sockets and light switches is well known. Most electrical fittings comprise a back box that is fitted to a surface, such as a wall, or recessed in such a surface, and a separate face place that is mounted on the back box. Electrical power supply cables are routed to enter / exit the back box, through apertures in the walls thereof, and are coupled to terminals in the face plate that is mounted on the back box to provide electrical power to the face plate. The face plate typically has an electronic device on its front face. There are a number of possible electrical devices such as switches, dimmer switches, plug sockets, temperature dials, and the like. The current designs and installation methods means that the front face (i.e. the face plate) is wired directly to the electrical power supply cables of an electrical power circuit (sometimes called a ring main).

[0007] Mounting a face plate to a newly installed back box, or as a replacement face plate for an existing back box can be a difficult and time-consuming process as the ring main wires must be cut to specific lengths, stripped, and fitted to the face plate by screw terminals. The ring main is often concealed within walls in which the back box is recessed, or mounted thereon and, in order to proceeding with such cutting and stripping of the wires, the installer usually has to pull these wires from within the walls and through the back box so that they have a sufficient length of cable to provide space to work when fitting the wires to the front plate. Once connected to the ring main wires, the excess cable length has to be pushed back into the wall so that the face plate can be fixed / mounted to the back box. Often, this can lead to the individual ring main wires being pulled out of the terminal on the front face. Moreover, when reinstalling the face plate, stress is put on the terminal connection point, to which the ring main wires are connected, which may lead to the ring main wires becoming loose and / or damaged. If these faults are undetected, the loose / damaged wires could become a fire hazard, or electrocution hazard.

[0008] Aspects and embodiments of the invention have been devised with the foregoing in mind.

[0009] SUMMARY

[0010] According to an aspect of the invention there is provided a power supply coupling for location in a back box of an electrical device, wherein the power supply coupling comprises a plurality of terminals configured to connect to an electrical power supply and a first plurality of electrical coupling elements, the power supply coupling further comprising a plurality of conductive paths between the plurality of terminals and respective ones of the plurality of electrical coupling elements. Such a power supply coupling provides a single universal component which can be used to upgrade existing back boxes or be fitted to new back boxes so that the power supply can be wired directly thereto.

[0011] Optionally, the power supply coupling further comprises an insulating layer configured to cover the electrically conductive surfaces of the power supply coupling. This reduces the exposed components that may transmit electricity, such as metal surfaces, and thus reduce the risk of electrocution to a user.

[0012] Optionally, the power supply coupling further comprises gaps in the surface of the insulating layer which is in connection with the back box; an electrically conductive tab in electrical connection with one of the plurality of terminals; and wherein the electrically conductive tab and the surface of the insulating layer are in the same plane. The tabs provide a direct connection between the surface of the back box in which the power supply coupling may be mounted and a terminal of the power supply coupling, for example, the earth terminal.

[0013] Optionally, the electrically conductive tab comprises holes configured to receive a fixing element with which to fix the power supply coupling in a back box.

[0014] Optionally, the power supply coupling is a cross shape having two perpendicular pairs of arms.

[0015] Optionally, the plurality of terminals is arranged along a first pair of the two perpendicular pairs of arms; and the plurality of electrical coupling elements are arranged along the second pair of the two perpendicular pairs of arms.

[0016] Optionally, the power supply coupling according further comprises an insulating sheath adjacent the plurality of electrical coupling elements extending upwardly therefrom.

[0017] Optionally, the insulating layer around the plurality of terminals comprises recesses so that the terminal screws are below the outer surface of the insulating layer.

[0018] According to a second aspect of the present invention there is provided a face plate for a power supply coupling according to the first aspect of the invention comprising: an electrical device; a second plurality of electrical coupling elements for electrically coupling the face plate to corresponding complementary ones of a plurality of electrical coupling elements of a power supply coupling, to which the face plate is mountable, the face plate further comprising conductive paths between the respective ones of the second plurality of electrical coupling elements and corresponding terminals of the electrical device such that, when mounted on a power supply coupling there is an electrical connection between the power supply coupling and the electrical device on the face plate.

[0019] According to a third aspect of the invention there is provided a kit of parts comprising a power supply coupling according to the first aspect and a face plate according to the second aspect of the invention. According to a fourth aspect of the invention there is provided an electrical device assembly, comprising: a back box configured to receive a portion of a power cable of an electrical power supply; a face plate according to the second aspect of the invention mountable on the back box; and a power supply coupling according to the first aspect of the invention mounted in the back box.

[0020] Optionally, the first plurality of electrical coupling elements and the second plurality of electrical coupling elements comprise complementary electro-mechanical couplings. This provides not only an electrical coupling between the back box and the face plate but an additional mechanical coupling. Such a mechanical coupling may provide additional mechanical strength to hold the face plate on the back box while the user secures face plate with a more permanent fitting, such as screws or the like.

[0021] Optionally, the first plurality of electrical coupling elements and the second plurality of electrical coupling elements comprise complementary push fit couplings. Push fit couplings can be easily pushed to fit together to save time, can be easily removed, and are simple to use.

[0022] Optionally, the second plurality of electrical coupling elements comprises a pin and the first plurality of electrical coupling elements comprises a female coupling element arranged to receive the pin to form a complementary engagement therebetween. The female pin located in the back box provides the advantage that when the external electrical power supply is coupled to the respective email coupling element, a user cannot be electrocuted, thus increasing safety. A pin and complimentary female coupling element also advantageously provides a strong electro-mechanical coupling between the face plate and the back box.

[0023] Optionally, the second plurality of electrical coupling elements comprise two pins and the first plurality of electrical coupling elements comprise two female coupling elements arranged to receive the corresponding pins of the second plurality of electrical coupling elements to form a complementary engagement therebetween. A two pin and two female coupling element arrangement provides the advantage that the live and neutral wires can be fixed directly to these elements. Thus, simplifying the construction as well as providing an additional electro-mechanical coupling element between the face plate and box. This increases the mechanical holding strength between the face plate and the back box.

[0024] Optionally, the second plurality of electrical coupling elements comprises three pins and the first plurality of electrical coupling elements comprises three female coupling elements arranged to receive the corresponding pins of the second plurality of electrical elements to form a complementary engagement therebetween. An additional third pin provides the advantage of increased mechanical strength. Optionally, the second plurality of electrical coupling elements comprises a female coupling element and the first plurality of electrical coupling elements comprises a pin, the female coupling element arranged to receive the pin to form a complementary engagement therebetween.

[0025] Optionally, the second plurality of electrical coupling elements comprises two female coupling elements and the first plurality of electrical coupling elements comprises two pins, the female coupling elements arranged to receive the corresponding pins to form a complementary engagement therebetween.

[0026] Optionally, the second plurality of electrical coupling elements comprises three female coupling elements and the first plurality of electrical coupling elements comprises three pins, the female coupling elements arranged to receive the corresponding pins of the first plurality of electrical elements to form a complementary engagement therebetween.

[0027] Optionally, the electrical coupling between the second plurality of electrical coupling elements in the face plate and corresponding complementary ones of the first plurality of electrical coupling elements in the back box comprises a touch contact coupling. A touch contact coupling requires less force when fitting the plates to the back box. Moreover this simplifies construction.

[0028] Optionally, the electric device on the face plate comprises a plug socket configured to receive an electrical plug

[0029] Optionally, the electric device on the face plate comprises a light switch.

[0030] BRIEF DESCRIPTION OF THE DRAWINGS

[0031] One or more specific embodiments in accordance with aspects of the present invention will be described, by way of example only, and with reference to the following drawings in which:

[0032] Fig. 1 illustrates a schematic diagram of an electrical fitting according to one or more embodiments of the present invention;

[0033] Fig. 2A illustrates a schematic diagram of a back box of an electrical fitting according to one or more embodiments of the present invention;

[0034] Fig. 2B illustrates a schematic circuit diagram of a back box of an electrical fitting according to one or more embodiments of the present invention;

[0035] Fig. 3 illustrates a schematic diagram of a face plate of an electrical fitting according to one or more embodiments of the present invention;

[0036] Fig. 4A illustrates a schematic diagram of a retro-fit component according to one or more embodiments of the present invention;

[0037] Fig. 4B illustrates a schematic diagram of a retro-fit component mounted in a back box according to one or more embodiments of the present invention; Fig. 5 is an image of an example removable faceplate according to an embodiment of one or more embodiments of the present invention;

[0038] Fig. 6 is an illustrative perspective view of a power supply coupling according to an one or more embodiments of the present invention;

[0039] Fig. 7 is an illustrative view of a power supply coupling when viewed from above according to one or more embodiments of the present invention;

[0040] Fig. 8 is an illustrative view of the underside of a power supply coupling (i.e. , when viewed from below) according to one or more embodiments of the present invention; and

[0041] Fig. 9 is an illustrative view of a power supply coupling with the internal components exposed according to one or more embodiments of the present invention.

[0042] DETAILED DESCRIPTION

[0043] The invention relates to improvements to existing electrical fittings and will be described in relation to Fig. 1 , which is a simplified schematic illustration of an electrical fitting 2 when viewed from a side angle in accordance with one or more embodiments of the invention. It should be noted that Fig. 1 is not to scale and may comprise further components than the ones described herein.

[0044] The electrical fitting 2 comprises a back box 10 and a removable front plate 12 (sometimes referred to as a face plate), which can be attached to the back box 10 by means of screws, clips, or other fasteners (not shown in this figure). Typically, the back box 10 is fixed onto a surface of a wall, or recessed in a cavity in a wall (fixings not shown in this figure). The back box 10 comprises various apertures to permit electrical power supply cable to be fed through them. Such power supply cables, when operating under a three-phase power supply, comprise a first cable, or wire, referred to as “live”, and a second cable, or wire, referred to as “neutral”. Often, a third cable, or wire, may be present to provide a ground / earth. The currently described one or more embodiments comprise “live”, “neutral” and “earth” wires.

[0045] It should be appreciated that most common back boxes require the user to cut their own apertures as desired so as to accommodate different cable arrangements and entry / exit points.

[0046] The back box 10 further comprises three electrical coupling elements 14, 16, and 18. In this embodiment, the electrical coupling elements 14, 16, and 18 are female coupling elements to which the electrical power supply cables are wired, either via screw terminals (not shown in this figure) or snap fit terminals (not shown in this figure). That is, the individual live, neutral, and earth wires of the electrical power supply cables are connected to respective ones of the three electrical coupling elements 14, 16, and 18.

[0047] The face plate 12 comprises three electrical coupling elements 20, 22, and 24, which are electrically connected to an electrical device (now shown in this figure) that is present on the face plate 12. In this embodiment, the three electrical coupling elements 20, 22, and 24 are male fittings, such as a pin as referred to herein, and are each configured to engage with a corresponding one of the electrical coupling elements 14, 16, and 18 when the face plate 12 is mounted onto the back box 10. In this embodiment, the pin 20 is configured to engage in a complementary way with the female coupling element 14 to form an electrical connection between the front face 12 and the electrical power supply wire connected to the female coupling element 14. The pin 22 is configured to engage with the female electrical coupling element 16 to form an electrical connection between the front face 12 and the ring main electrical power supply wire connected to the female coupling element 16. The pin 24 is configured to engage with the female coupling element 18 in the same manner, to form an electrical connection between the front face 12 and the ring main electrical power supply wire connected to the female coupling element 18.

[0048] Since the female electrical coupling elements 14, 16, and 18 are connected to the individual wires of the ring main, when the front face 12 is mounted to the back box 10, the pins 20, 22, and 24 likewise are electrically connected to these wires. Therefore, any device in the front plate 12, such as a plug socket or light switch, will be connected to the electrical power supply via this complementary coupling arrangement.

[0049] While not strictly necessary to achieve electrical connection, the complimentary coupling between the pins 20, 22 and 24 and the female coupling elements 14, 16 and 18 also provides a mechanical connection between the front face 12 and the back box 10. However, it should be appreciated that this is an optional addition to the primary function of providing an electrical connection between the front face 12 and the back box 10.

[0050] The back box 10 will now be described in more detail with reference to Figs. 2A and 2B. Fig. 2A is a schematic diagram showing the back box 10 when viewed from above in accordance with an embodiment of the invention. As described in relation to Fig.1 , the back box 10 comprises the three female electrical coupling elements 14, 16, and 18.

[0051] Fig. 2a shows how an electrical power supply cable 28 is connected to the back box 10. As can be seen, the electrical power supply cable 28 comprises three separate individual wires numbered 30, 32, and 34, which connect to terminals 36, 38, and 40 respectively. The terminals 36, 38, and 40 could be screw fittings that are commonly known in the art, or other fittings that permit the individual ring main wires to be fixed in a secure way and form an electrical connection between them and the respective wires. In this embodiment, there are additional terminals 42, 44, and 46, which connect to wires 48, 50, and 52 respectively of a second electrical power supply cable 29. In such an arrangement, i.e., one with two electrical power supply cables entering / exiting the back box 10, the electrical fitting 2 is part of a so- called “ring main”. As will be appreciated, if the back box is located at the end of an electrical “spur” from the “ring main”, then only one electrical power supply cable would enter the back box and only one set of three terminals would be required in the back box.

[0052] Fig. 2B is a schematic illustrative diagram showing the back box 10 from above and including an illustrative schematic circuit diagram. The circuit diagram shows how the previously mentioned terminals 36, 38, 48, 42, 44, and 46 are connected to the female coupling elements 14, 16, and 18. As described above with reference to Fig. 2A, there are three ring main wires connected to the electrical terminals 36, 38, and 40 and three other ring main wires that connect to the electrical terminals 42, 44, and 46. Two neutral ring main wires 34, and 52 are connected to electrical terminals 40 and 46 respectively. These terminals are electrically connected to the female coupling element 14 by way of an electrical path 52, which is indicated by the dotted lines. Similarly, live ring main wires 30 and 48 are connected to electrical terminals 36 and 42 respectively. These are in turn connected to the female coupling element 16 by way of an electrical path 54, which is indicated in solid lines. Finally, two earth ring main wires 32 and 50 are connected to the electrical terminals 38 and 44 respectively. These are connected to female coupling element 18 by electrical path 56, which is indicated by the dashed lines. The female coupling element 18 may, in some arrangements, be electrically coupled to the back box 10 so as to provide earthing via the back box 10. This is in accordance with “best practice” in the UK.

[0053] The face plate 12 will now be described in more detail with reference to Fig. 3, which is a schematic illustration of a double UK three pin plug (Type G). Please note that this is not to scale, and other components and / or fittings may not be described herein. Fig. 3, shows the face plate 12 from a back side, i.e., a side that would face the back box 10 when mounted to the back box.

[0054] In addition to the components described above in relation to Fig. 1 , the face plate 12 comprises a first electrical device 62 and a second electrical device 64, both of which are indicated with the dash-dot lines. The first electrical device 62 and the second electrical device 64 both comprise three apertures to receive a complimentary three pin plug: earth apertures 66 and 68, neutral apertures 70 and 72 and live apertures 74 and 76 respectively. The apertures for receiving an earth pin of an electric plug will be referred to hereinafter as earth apertures 66 and 68. Earth apertures 66, 68 contain respective electrical couplings that are electrically connected to the pin 20 by electrical path 78. The apertures for receiving a neutral pin of an electric plug will be referred to hereinafter as neutral apertures 70 and 72. Neutral apertures 70, 72 contain respective electrical couplings that are electrically connected to the pin 24 by electrical path 80. The apertures for receiving a live pin of an electric plug will be referred to hereinafter as live apertures 74 and 76. Live apertures 74, 76 contain respective electrical couplings that are electrically connected to the pin 22 by electrical path 82. When the front face 12 is mounted on back box 10, the pins 20, 22, and 24 engage with female coupling elements 14, 16, and 18. Electrical connections are formed between the respective electrical couplings located in the apertures of electrical devices 64 and 66 with female coupling elements 14, 16, and 18 of the back box 10, via the pins 20, 22, and 24 of the face plate 12. This, in turn means, that the electrical devices 62 and 64 will be electrically connected to the electrical power supply cables via the terminals and previously described electrical paths 52, 54, and 56.

[0055] The arrangement described above has many advantages over existing solutions where the device on the face plate 12 would normally be wired directly to the ring main wires and the back box merely serving as a mounting point. By wiring the electrical power supply cables to the back box and providing a convenient, electrical coupling system like the one described above, one can simply mount the face plate to the back box to achieve an electrical connection to the electrical power supply. This is a simple procedure meaning that changing a face plate may be relatively straightforward, because one can merely remove the current face plate and replace it with another compatible face plate. Changing the design or look of the face plate may be desirable when remodelling a room in which the electrical fitting 2 is mounted. The system of the present invention may provide a convenient way to replace an existing face plate with a new / replacement one.

[0056] In addition to the above, the improved system may reduce the length of ring main cable required to be left after the so called “first fix”. The first fix is the preparation stages of wiring a building, where an electrician prepares the skeleton of the building electrical power supply, i.e. , the installation of power supply cables. This usually occurs before plastering is done and so most of the wiring will not be visible afterward. Normally, during the first fix, the electrician will mount the back boxes, feed the power supply cable to it, and leave long lengths of excess cable exposed so that, once the plastering is done, they can return to the site and fit the face plates.

[0057] The new electrical fitting 2 as described above means that during the first fix, the electrician can wire directly and easily to the terminals provided in the back box 10. The excess length of cable that is normally left is not required, and results in much less wastage of electrical cable for new builds or situations when a house is being re-wired. This may provide cost-savings as well as providing environmental benefits, through less wastage.

[0058] The system of the present invention may also provide time savings during a so-called “second fix”, which is when electricians will fit the face plates to the back boxes after the plastering work has been completed. At the same time, they will normally wire the face plate directly to the electrical power supply cables. As explained above, in one or more embodiments of the present invention the electrical power supply cables are already wired to the back box 10 and so the electrician, on their return to conduct the “second fix”, may need only to mount a compatible face plate 12 to the back box 10 in order to complete the installation.

[0059] Figs. 1 to 3 above disclose a power supply coupling system which comprises the terminals 36, 38, 40, 42, 44, and 46, and the pins 20, 22, 24. In those figures, the power supply coupling is mounted directly in the back box 10 and can be supplied with the back box 10. Such a system may be appropriate for new installations where either the existing back boxes are being replaced, or where new fittings are being mounted in a new build. However, a person skilled in the art will appreciate that there are many existing electrical fittings comprising back boxes. A power supply coupling suitable for retrofitting in existing back boxes will be described with reference to Figs. 4A and 4B. The features of Figs. 4A and 4B that are the same as Figs. 2A and 2B are indicated with the same reference numerals.

[0060] Fig. 4A is a schematic illustrative diagram showing a power supply coupling 90 when viewed from above. Fig. 4B is a schematic illustrative diagram showing the power supply coupling 90 mounted in a back box 100 when viewed from above. The back box 100 differs from the back box 10 in that it is already mounted upon or within a surface (not shown in these figures).

[0061] The power supply coupling 90 comprises a support member 92 which is suitable to be mounted in an existing back box, i.e., back box 100. Such a mounting may be removable or permanent by way of fixings elements such as rivets, screws, tape, or any other fixing (not shown in these figures).

[0062] The power supply coupling 90 comprises terminals 36, 38, 48, 42, 44, and 46 and female coupling elements 14, 16, and 18 that were previously described in relation to Figs. 2A and 2B. As will be evident from the figures, the conductive paths between respective ones of the plurality of terminals and the corresponding female coupling elements that was described in relation to Fig. 2B is not shown here. However, we refer to Fig. 2B for this information, which is incorporated into this embodiment.

[0063] In this embodiment, the support member 92 is formed of a rectangular cross with the female coupling elements 14, 16, and 18 situated along one length of the cross and the terminals 36, 38, 48, 42, 44, and 46 to which power supply wires (not shown in this image) mounted on the other length of the cross perpendicular to the length which the female coupling elements are mounted.

[0064] The support member 92 could be formed of any existing material, such as a plastic material according to safety standards.

[0065] In use, the power supply coupling 90 and be positioned within a back box and secured therein by way of the fixings described above. Once this has been completed, the external power supply wires may be fixed to the terminals as described above and a compatible face plate, mounted on the back box. The power supply coupling 90 could be supplied as a kit or parts with a compatible face plate (not shown here in these figures) and used to retrofit existing back boxes. An example face plate could be the face plate described with reference to Fig. 3.

[0066] The power supply coupling 90 provides the advantage that existing back boxes can be retrofitted to include the advantageous effects previously described above in relation to Figs. 1 to 3. This means that a user need not purchase a back box if they wish only to upgrade their existing electrical devices.

[0067] Fig. 5 is an image of an example removable faceplate 12 according to an embodiment of the invention. The features of Fig. 5 that are the same as those illustrated in Fig. 1 are indicated with the same reference numerals.

[0068] As can be seen, the removable face plate 12 comprises the three electrical coupling elements 20, 22, and 24, which are rectangular elongate members similar to the pins of a UK three pin plug. The coupling elements 20, 22, and 24 are arranged to electrically engage with corresponding female coupling elements on the back box (not shown in this image). The advantage of using this shape pin is that they are readily available due to their prevalence in the market already, which may mean that these parts are lower-cost.

[0069] The power supply coupling 90, previously illustrated in Figs. 4a and 4b, will be described in more detail with reference to Figs. 6 and 7. The features of Figs. 6 and 7 that are the same as those illustrated in Figs. 4a and 4b are indicated with the same reference numerals. Fig. 6 is an illustrative perspective view of the power supply coupling 90 and Fig. 7 is an illustrative view of the power supply coupling 90 when viewed from above (plan view).

[0070] As previously mentioned, the support member 92 is formed of a rectangular cross shape with the female coupling elements 14, 16, and 18 situated along a first pair of arms of the cross. The terminals 36, 38, 40, 42, 44, and 46 to which power supply wires (not shown in these images) are mounted are situated on a second pair of arms of the cross that are perpendicular to the first pair of arms, on which the female coupling elements are mounted.

[0071] The power supply coupling comprises one or more apertures 50 (e.g., screw holes), through which fastening elements can be passed to fix the power supply coupling to the rear, inner surface of a back box (not shown, but one such as that described in relation to Figs. 1 , 2a, and 4b). The back box may be one that is already fitted into a wall, which an electrician can retrofit with the power supply coupling 90. Alternatively, the power supply coupling 90 may be fixed to new back boxes before they are fitted to a wall. The power supply coupling 90 provides flexibility to upgrade existing or new back boxes to be compatible with face plates such as those described in relation to Figs. 1 , 2b, 3, or 5.

[0072] In this embodiment, the terminals 36, 38, 40, 42, 44, and 46 are double-sided terminals allowing power supply wires (not shown in these images) to be inserted from both sides. This arrangement provides additional electrical connection points to the power supply coupling 90, which may result in easier fitting / installation. The double-sided terminals mean that wires can enter either side of the back box (not shown) to which the cross-piece power supply coupling 90 is mounted. Therefore, the cables will not require bending within the back box, as is often the case in conventional socket arrangements, to be connected to the power supply coupling 90. This may improve ease of fitting and in turn may result in faster installation. Additionally, there will be fewer forces on the wires when fitted into the terminals due to reduction of bending of cables in the back box.

[0073] The double-sided terminals are located on the second pair of arms of the power supply coupling 90 so that entry points thereof are oriented perpendicular to the vertical sides of any back box in which the power supply coupling is mounted. Arranging the terminals in this manner results in similar distances between cable entry points of the back box and entry points of the terminals, because they directly face the cable entry / exit points of the back box, and are roughly equidistant therefrom. Typically, cable entry / exit points of the back box will be in vertical side walls of the back box. Generally, a power supply cable with the live, neutral, and earth wires will be electrically coupled to one of the two groups of terminals (i.e. , either the group of terminals 36 to 40 or 42 to 46). Ensuring the distance between each respective terminal for each respective wire and the cable entry / exit point is the same means that the wires can be cut off at the same length and easily stripped in preparation for connecting. In current designs, the three separate wires must be cut to different lengths due to the different locations of the terminals to which they are connected. This makes wiring up a terminal in a conventional arrangement time consuming and physically more difficult than the arrangement of this embodiment.

[0074] The power supply coupling 90 comprises an insulating layer, such as a plastic material, which reduces the risk of electrocution by minimising the exposed electrical components and surfaces. The coupling elements 14, 16, and 18 are completely enclosed in the insulating material, which forms a sheath extending upward from the surface of the power supply coupling. The insulating sheath is shaped so as to receive male coupling elements of a corresponding faceplate and insulate any exposed surfaces of said male coupling elements. This is similar to standard UK plug fittings that have the female electrical connection(s) underneath the insulating faceplate. This improves the safety of the universal retrofit electrical coupling 90, because when connected to the electrical power source, it makes it more difficult for a user to accidentally touch live parts and electrocute themselves.

[0075] An additional safety feature is the sunken terminal screws of the corresponding terminals which results in the top of the metal screws being situated below the outer insulating surface of the power supply coupling 90. Once the power source is connected to the terminals, the risk of electrocution is reduced due to minimising the exposed metallic components that would otherwise transmit electric current. Optionally, the screws, or heads of the screws, may be composed of an insulating material to achieve the same effect of reducing exposed metal components.

[0076] Additional features of the power supply coupling 90 will be described with reference to Figs. 8 and 9. Fig. 8 is an illustrative diagram of the underside of the power supply coupling 90 (i.e. , when viewed from below) and Fig. 9 shows the power supply coupling 90 with the internal components exposed (i.e., the previously described external insulating surface is removed).

[0077] As can be seen from Fig. 9, the bottom of the power supply coupling 90 comprises a tab 94 that is in electrical connection with earth terminal 38 (not shown in this figure) and a tab 96 that is in electrical connection with earth terminal 44 (not shown in this figure). Fig. 8 shows the bottom surface of the tabs 94 and 96 are exposed by gaps in the insulating surface on the bottom of the power supply coupling. That is, the insulting surface and the surface of the tabs are in the same plane. Consequently, the earth terminals 38 and 44 will be in electrical connection with the back box when the power supply coupling 90 is mounted. Although a full back box is not shown in Fig. 9, the connection between the earth terminals 38 and 44, the tabs 94 and 96, and such a back box is illustrated by way of showing it mounted on a plate 110. In this figure, the plate 110 represents the rear, inner surface of the back box to which a power supply coupling 90 could be mounted.

[0078] According to “best practice” in the UK, the back box must be earthed (i.e., grounded) which is usually achieved by so called “earth tail” wires connecting the earth wire to the back box. As will be appreciated by a person skilled in the art, in the normal system where the power supply is connected to the faceplate, the earth tail wire must join the back box to the faceplate to successfully earth the back box. The power supply coupling 90 and tabs 94 and 96 removes the need to supply such an earth tail because of the direct earthing they provide (by contact between earth terminals 94, 94 and 98 and the back plate (“110”) of back box). While not shown in Fig. 9, the earth terminal 18 would also likewise be electrically connected to the back box in the same way as earth terminals 38 and 44 (see tab 98 on Fig. 8).

[0079] The electrical coupling elements 14, 16, and 18 on the back box 10 are described as female electrical coupling elements arranged to receive corresponding male coupling elements 20, 22, and 24 in order to complementarily engage to form an electrical connection. However, it should be appreciated that they may easily be swapped for male coupling elements. Of course, in order to form the complementary engagement with the front face, the electrical coupling elements on the front face would likewise have to be swapped from female to male connection elements. In other embodiments, it could be envisaged that the three complementary electrical coupling elements are formed as a single pin with separate electrical connection points. Examples of such connectors is a so called ‘phone connector’ (also known as phone jack, audio jack, headphone jack, stereo jack or jack plug) comprising three coaxial connection points; coaxial cables; or other single pin solutions.

[0080] The face plate 12 is described above having two three-pin electrical plug sockets (electrical devices 62 and 64). It should be appreciated that other electrical devices could be equally implemented on such a face plates 12. Such devices could be light switches, household appliance switches, safety switches, sensors, or other plug arrangements (two pin for example). Moreover, the term “plug socket” may include other safety switches that were not shown in the figures above, such as switches to isolate the conductive paths 52, 54, or 56.

[0081] The earth sockets 66 and 68 are relevant to the British style Type G, 3 pin plug sockets. Of course, the pin 20 could equally be in electrical connection with earth contact plates that are used in European countries in the Type G, two pin sockets. This would mean that instead of being an aperture to receive a plug pin, apertures 66 and 68 would be metal plates such as used in European style plugs.

[0082] Some countries and devices do not require earthing and so, in other embodiments of the present invention, the earth connection between the front face and back plate may be removed entirely. This results in only two complementary electrical connections required for the live and neutral ring main wires. The support member 92 is described above as being a rectangular cross. However, it will be appreciated that any shape may be used in order to provide a support for the one or more coupling elements and terminals.

[0083] Although the embodiment illustrated in Figs. 6 to 9 comprises an insulating sheath completely enclosing the coupling elements 14, 16, and 18, this is not an essential feature and a person skilled in the art can readily appreciate that it would function without such insulating sheaths. The invention is not limited to comprising the insulating sheaths.

[0084] The embodiment illustrated in Figs. 6 to 9 comprises three tabs 94, 96, and 98. However, it will be appreciated that only one tab may be required to provide the earthing required. The invention is not limited to three tabs.

[0085] It will be understood by those skilled in the art that the drawings are merely diagrammatic and that further items of equipment may be required in a commercial apparatus. The position of such ancillary items of equipment forms no part of the present invention and is in accordance with conventional practice in the art.

[0086] As used herein any reference to “one embodiment” or “an embodiment” means that a particular element, feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment. Moreover, one or more features of different embodiments may be combined to create further embodiments not specifically described herein, and any one or more features may be combined consistent with their technical and operational compatibility. To the extent that one or more features from respective embodiments may not be combined without being inconsistent with the technical and / or operational compatibility such features from respective embodiments may be selected for combination which do not have such technical and / or operational compatibility. All such embodiments are contemplated within the scope of this disclosure.

[0087] As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Further, unless expressly stated to the contrary, “or” refers to an inclusive or and not to an exclusive or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

[0088] In addition, use of the “a” or “an” are employed to describe elements and components of the invention. This is done merely for convenience and to give a general sense of the invention. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.

[0089] In view of the foregoing description, it will be evident to a person skilled in the art that various modifications may be made within the scope of the invention.

Claims

CLAIMS1. A power supply coupling for location in a back box of an electrical device, wherein the power supply coupling comprises a plurality of terminals configured to connect to an electrical power supply and a first plurality of electrical coupling elements, the power supply coupling further comprising a plurality of conductive paths between the plurality of terminals and respective ones of the plurality of electrical coupling elements.

2. A power supply coupling according to claim 1 , further comprising an insulating layer configured to cover the electrically conductive surfaces of the power supply coupling.

3. A power supply coupling according to claim 2 further comprising: gaps in the surface of the insulating layer which is in connection with the back box; an electrically conductive tab in electrical connection with one of the plurality of terminals; and wherein the electrically conductive tab and the surface of the insulating layer are in the same plane.

4. A power supply coupling according to any preceding claim, wherein the electrically conductive tab comprises holes configured to receive a fixing element with which to fix the power supply coupling in a back box.

5. A power supply coupling according to any preceding claim, wherein: the power supply coupling is a cross shape having two perpendicular pairs of arms.

6. A power supply coupling according to claim 5, further wherein: the plurality of terminals is arranged along a first pair of the two perpendicular pairs of arms; and; the plurality of electrical coupling elements are arranged along the second pair of the two perpendicular pairs of arms.

7. A power supply coupling according to any preceding claim, further comprising: an insulating sheath adjacent the plurality of electrical coupling elements extending upwardly therefrom.

8. A power supply coupling according to claims 2 to 7, wherein:the insulating layer around the plurality of terminals comprises recesses so that the terminal screws are below the outer surface of the insulating layer.

9. A face plate for a power supply coupling according to any of claims 1 to 8, comprising: an electrical device; a second plurality of electrical coupling elements for electrically coupling the face plate to corresponding complementary ones of a plurality of electrical coupling elements of a power supply coupling, to which the face plate is mountable, the face plate further comprising conductive paths between the respective ones of the second plurality of electrical coupling elements and corresponding terminals of the electrical device such that, when mounted on a power supply coupling there is an electrical connection between the power supply coupling and the electrical device on the face plate.

10. A kit of parts comprising a power supply coupling according to any of claims 1 to 7 and a face plate according to claim 9.

11. An electrical device assembly, comprising: a back box configured to receive a portion of a power cable of an electrical power supply; a face plate according to claim 9 mountable on the back box; and a power supply coupling according to claims 1 to 8 mounted in the back box.

12. An electrical device assembly according to claim 11 , wherein the first plurality of electrical coupling elements and the second plurality of electrical coupling elements comprise complementary electro-mechanical couplings.

13. An electrical device assembly according to claims 11 or 12, wherein the first plurality of electrical coupling elements and the second plurality of electrical coupling elements comprise complementary push fit couplings.

14. An electrical device assembly according to any of claims 11 to 13, wherein the second plurality of electrical coupling elements comprises a pin and the first plurality of electrical coupling elements comprises a female coupling element arranged to receive the pin to form a complementary engagement therebetween.

15. An electrical device assembly according to any of claims 11 to 13, wherein the second plurality of electrical coupling elements comprise two pins and the first plurality of electricalcoupling elements comprise two female coupling elements arranged to receive the corresponding pins of the second plurality of electrical coupling elements to form a complementary engagement therebetween.

16. An electrical device assembly according to any of claims 11 to 13, wherein the second plurality of electrical coupling elements comprises three pins and the first plurality of electrical coupling elements comprises three female coupling elements arranged to receive the corresponding pins of the second plurality of electrical elements to form a complementary engagement therebetween.

17. An electrical device assembly according to claims 11 to 13, wherein the second plurality of electrical coupling elements comprises a female coupling element and the first plurality of electrical coupling elements comprises a pin, the female coupling element arranged to receive the pin to form a complementary engagement therebetween.

18. An electrical device assembly according to any of claims 11 to 13, wherein the second plurality of electrical coupling elements comprises two female coupling elements and the first plurality of electrical coupling elements comprises two pins, the female coupling elements arranged to receive the corresponding pins to form a complementary engagement therebetween.

19. An electrical device assembly according to any of claims 11 to 13, wherein the second plurality of electrical coupling elements comprises three female coupling elements and the first plurality of electrical coupling elements comprises three pins, the female coupling elements arranged to receive the corresponding pins of the first plurality of electrical elements to form a complementary engagement therebetween.

20. An electrical device assembly according to claim 11 , wherein the electrical coupling between the second plurality of electrical coupling elements in the face plate and corresponding complementary ones of the first plurality of electrical coupling elements in the back box comprises a touch contact coupling.

21. An electrical device assembly according to any of claims 11 to 20, wherein the electric device on the face plate comprises a plug socket configured to receive an electrical plug.

22. An electrical device assembly according to any of claims 11 to 21 , wherein the electric device on the face plate comprises a light switch.

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