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(11) | EP 2 367 242 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | A recessed wall-mounted electrical component |
| (57) The present invention provides a wall-mounted electrical component that has a box
(12) that can be mounted within a wall recess (14) and a cover (10). Electrical cables
are connected to terminals (26) within the box rather than to terminals within the
cover. In order to provide an electrical connection to the cover (10), the cover includes
terminals (46) that, when the cover is fitted onto the box, contact the terminals
(26) in the box so that an electrical current or signal can pass between the cover
and the box. The component may be a socket (as shown) or a switch.
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Technical Field
[0001] The present invention relates to a recessed wall-mounted electrical component especially for use in a domestic or office setting, for example an electrical socket for transferring electrical power, data, telephone or television signals etc. or a switch.
Background art
[0002] Recessed wall-mounted electrical plug sockets and switches are, of course, well known for supplying and controlling electrical power from cables within a wall. They include a box that is mounted within a recess in a wall into which the end of the wall cabling extends. The box has an open front face and a cover plate is provided that covers the front face of the box and isolates the electrical cabling within the box. The cover also includes some functionality, e.g. a switch or connectors for making electrical connections to a plug. The cover also includes electrical terminals to which the power cables within the box are connected. This means that when the cover is removed from the box, the cabling within the box is exposed and, because the cabling is connected to the cover itself, the cabling is pulled out from within the box when the cover is pulled away from the box.
[0003] As used herein the term "wall" includes not only vertical walls of rooms but also ceilings, skirting boards, fascias, work surfaces and indeed any surface containing a recess for holding electrical components.
[0004] When decorating a room containing a wall mounted electrical socket or a switch, the cover is often removed, leaving the live cabling attached to the cover exposed. The live terminals can easily be touched accidentally by the decorator or by the decorating materials, for example, wet wall paper or paint, causing a short circuit or, more importantly, possibly causing the decorator to suffer electrocution.
[0005] A further problem with presently designed wall-mounted electrical sockets and other components is that the box is square in shape and the recess in which the box sits must be chiselled out with a tool. This is time consuming and it is often difficult to ensure that the recess has the correct dimensions to accommodate the box exactly.
Disclosure of Invention
[0006] In accordance with the present invention, there is provided a recessed wall-mounted electrical component, as set out in the accompany claims.
[0007] Briefly stated, the present invention provides a box that can be mounted within a wall recess. Electrical cables within the wall or within channels attached to the wall are connected to terminals within the box (referred to here as "box terminals") rather than to terminals within the cover. In order to provide an electrical connection to the cover, the cover also includes terminals (referred to here as "cover terminals") that, when the cover is fitted onto the box, contact the box terminals so that an electrical current or signal can pass between the cover and the cabling.
[0008] The present invention can be used in a number of wall-mounted applications, for example it can be a switch in which the switching components are contained within the cover, which can be operated by a mechanism, e.g. a lever or knob, that is accessible to the outside, for example it is placed on the outside surface of the cover. Alternatively or in addition, the electrical component may be a socket into which a plug may be inserted. In this case, the cover includes connectors providing electrical connections between the plug and the cover terminals. In this way, electrical current can be transferred from an electrical cable in the wall, by way of the box terminals and the cover terminals, to the electrical connectors within the cover and from there to the plug itself (and vice versa). The electrical current may be a power source, e.g. mains electricity, or it may be an audio, video, telephone, data or other signal. The present invention is particularly useful for CAT-5 cable.
[0009] In order to prevent a cover for one application being attached to an already fitted box intended for a different application, which can be dangerous, the box and the cover could be configured so that they can only be secured together (and electrical connection between them established) when they are both intended for a specific application, thereby preventing, for example, (a) a cover for a telephone or a CAT-5 connector being secured to a box connected to the mains or (b) a switch rated for use for a lighting circuit being used in a box intended for high power applications, e.g. circuits for electric cookers or electric showers. In other words, the boxes and/or the covers can be made so that they differ from application-to-application. The configuration to prevent the fitting of the wrong cover to a box could simply be:
- (a) the provision of matching projections and recesses in the housing of the box/cover that key together to allow the two parts to fit together when intended for the same application and prevent the two parts fitting together when intended for different purposes; or
- (b) the provision of differently shaped cover terminals e.g. square, round, rectangular, for different purposes and the corresponding shaping of a recess that houses the box terminals so that the cover terminals cannot fit into the recesses, and the terminals can contact each other, when the shape of the cover terminals do not match the shape of the recesses for the box terminals. This allows the terminals to be brought into contact with each other when the cover terminals are of a corresponding shape to the recesses for the box terminals but not otherwise; or
- (c) arranging the cover terminals in a different pattern or configuration or in different locations for the various purposes of the electrical components and arranging the box terminals in a corresponding pattern or in corresponding locations when the box is intended for use with that cover. Thus the cover and box terminals can only contact each other when they are arranged in corresponding configuration or in corresponding locations.
[0010] As will be appreciated, when the cover is removed from the box, it can be lifted free of the box for the purposes of decoration of the surrounding wall without any trailing cables. Although the terminals within the box will still be accessible, they are held within the box and are not dragged out when the cover is removed and it is therefore much harder to contact them accidentally. In a preferred embodiment, the terminals within the box are themselves mounted within a recess to further reduce the possibility that they can be accidentally contacted, e.g. by a decorator or by decorating materials. When the terminals within the box are recessed, the terminals of the cover preferably take the form of projections that extend into the corresponding recesses in the box holding the box terminals when the cover is secured to the box. In order to ensure that good electrical contact is made between the box terminals and the cover terminals the terminals should make an electrical connection with each other over a small range of separation distances between the cover and the box, e.g. by making at least one of the terminals spring-loaded or by providing one of the terminals as a sleeve into which the other terminal fits.
[0011] The box terminals may be, as described above, located in a recess, thereby reducing the chance of accidental contact being made with the live terminals. This is believed to provide a safe arrangement. However, it is also possible to provide a switch that may be activated by the fitting and removal of the cover to the box and that electrically disconnects some or all of the box terminals from the wall cabling when the cover has been removed. This is especially advantageous when the wall cabling is a high power supply, e.g. a mains electricity supply.
[0012] One advantage of the present invention is that the electrical component can be made to be the same size as the existing corresponding components so that the box of the present invention can be fitted into an existing recess and so can be retro-fitted when a replacement component is provided.
[0013] The present invention can be used in any mains electricity supply, any plug configuration and with any voltage found anywhere in the world.
[0014] In accordance with a further aspect of the present invention, there is provided a recessed wall-mounted electrical component having a box, which can be mounted within a recess in a wall, and a cover. The box has a substantially circular cross section so that the recess can be formed using a drill-powered rotary tool having the same diameter as that of the box so that the box can easily be fitted into the recess thus formed. The forming of the recess with a rotary tool is quicker than forming a rectangular or square recess.
Brief Description of Drawings
[0015] There will not be described, by way of example only, an electrical power socket in accordance with the present invention by reference to the accompanying drawings in which:
Figure 1 is a view of the front of the socket, which is configured for a UK-type square pin plug;
Figure 2 is a sectional view taken along the line A-A of Figure 1; and
Figure 3 is a sectional view of an alternative configuration of part of the socket of Figures 1 and 2.
Detailed Description of a Preferred Embodiment
[0016] Figures 1 and 2 show an electrical power socket having a box 12 that fits into a recess 14 in a wall 16 (both shown in broken lines in Figure 2) and a cover 10 that can be attached to the box, as discussed below.
[0017] The recess 14 can be formed by a rotary tool attached to a drill and is therefore circular in cross-section. The tool may also have an extension that forms an additional cavity 18 within the wall for ease of threading electrical cables through to the box 12. As will be appreciated, box 12 is also circular in cross-section so that it fits snugly within the circular recess 14. The box need not, of course, be circular and could be square or oblong, especially if more than one socket (or other electrical component) is provided in the cover 10; in this case, the recess 14 can be formed by known method, e.g. using a chisel.
[0018] The box can be held within the recess by means of screws (not shown) that extend through screw holes 20 into the wall. The screw holes 20 are preferably curved to allow the orientation of the box to be adjusted during its fitting. Alternatively, the box can be held by friction or by lugs (not shown) projecting from the side walls of the box and engaging the neighbouring wall.
[0019] The box also includes a partition 22 that includes a front face 22'. Behind the partition 22, there is a cavity 24 that accommodates electric cable (not shown). Three terminals 26 are held by the partition 22 and are spaced backwards from the front face 22', thereby forming openings 28 between the terminals 26 and the front face 22'. The partition may be separable form the rest of the box to enable the wall cables to be accessed without having to remove the whole box from the wall recess.
[0020] Each terminal 26 is of a standard design and includes a hole 30 into which the bare end of an electric cable can be inserted. A grub screw 32 can compress the bare ends of the cables to form a good electrical connection between the cable and the terminal 26.
[0021] Because the terminals 26 are spaced back from the front wall 22' of the partition, it is much harder for the terminals 26 to be touched accidentally when the cover 10 has been removed.
[0022] The cover 10 includes three openings for, respectively, the live, neutral and earth pins of a standard square pin plug. Held within the openings 40, sprung connectors 42 , e.g. known standard connectors, are provided that engage the plug pins. The connectors 42 extend through the cover 10 and include a narrowed section 44. Sleeve-shaped terminal pins 46 can slide over the narrow sections 44 while maintaining good electrical contact with them. The terminal pins 46 are spring loaded - each pin including a flange 48 and a helical spring 50 arranged between the flange and the body of the cover 10. The diameter of each of the cover terminal pins 46 is smaller than the corresponding openings 28 in the box so that, when the cover is moved to the right (as shown in Figure 2), they pass into the openings 28 and engage the terminals 26, thereby establishing electrical contact between the box terminals 26 and the cover terminals 42, and ultimately between the cables in the wall and the plug pins (not shown). The cover 10 can be secured to the box 12 by means of screws 60 engaging in threaded blind holes 62 in the box.
[0023] In order that the front of the cover 10 can be in the right orientation, the box must be correctly orientated within the recess 14, which can be achieved by elongating the screw holes 20 so that it is possible to rotate the box relative to the screws (not shown). Thus, it is possible to mount the box in the recess in approximately the correct orientation mounting using screws in the screw holes but making final adjustments to the orientation of the box before finally tightening the screws when it has achieved the right orientation. The holes will generally be curved in shape to allow for this final adjustment.
[0024] The cover 10 is preferably larger than the box 12 (see overhang 70) so as to hide the box when the cover is secured to the box.
[0025] As shown in Figure 1, the cover 10 is also of circular cross-section, although it can be of a different cross-section to that of the box, e.g. square.
[0026] The socket may have any configuration suitable for any shape of plug and it can have two or three terminals.
[0027] As will be appreciated, the socket of the present invention may be used for providing an electrical connection with cables other than power cables, for example data cables, video cables, telephone cables and audio cables, such as CAT-5 cabling.
[0028] Although shown as a cabling socket in Figures 1 and 2, the arrangement can also be used as a switch, where the switching components are included within the cover 10. The switching components may be any standard switching components currently used, including dimmer switches. More than one socket, switch (or other electrical component) may be included in the cover 10.
[0029] Because the cover lifts clear away from the box when the screws 60 are undone and because the terminals 26 are recessed behind the front face 22' of the partition 22, the arrangement of the present invention is much safer than known designs.
[0030] Instead of the arrangement shown in Figure 3, where the end face of the terminals 26 are flat, they may have a collar 72 (see Figure 3) that makes electrical contact with the terminal pins 46 when the cover 10 is attached to box 12. In this case, the terminal pins 46 need not be spring-loaded.
[0031] In summary, it can be seen that one aspect of the present invention is the provision of a wall-mounted electrical box for containing live terminals 26 and a cover 10 that can be secured to, and removed from, the box 12 and when removed, none of the components in the cover are live. The cover therefore acts like a plug in that it has protruding terminals that engage with the live terminals in the box when the cover is secured to it. In addition, the live terminals within the box are located in a recess to minimise the risk that they are touched accidentally when the cover has been removed. This risk can be further minimised by the inclusion of a switch (not shown) that is activated by the fitting and removal of the cover to the box and that breaks the electrical connection between at least one of the box terminals and the corresponding electrical cables in the wall (which should include at least the live cable) when the cover 12 has been removed and re-establishes the electrical connection when the cover 10 is re-connected to the box 12.
1. A wall-mounted recessed electrical component comprising:
- a box for mounting within a wall recess and comprising
- an open face configured to face outwardly from the wall when the box is mounted in the wall recess and
- a terminal, which will be referred to as the "box terminal", that can be electrically connected to an electrical cable and that has a contact surface that is accessible through the open face of the box; and
- a cover that can be secured to the box over the front face thereof and that includes a terminal, which will be referred to as the "cover terminal", that is configured to make electrical contact with the contact surface of the box terminal when the cover is secured to the box.
2. An electrical component as claimed in claim 1, wherein the box includes a partition
having a front side facing the open face of the box and a rear side facing away from
the open face and wherein the box terminal, is mounted on the partition.
3. An electrical component as claimed in claim 2, wherein box terminal includes a connector
for electrically connecting the box terminal to an electrical cable and wherein the
connector is accessible from the rear side of the partition, which partition is optionally
secured to the rest of the box in such a way that it is separable from the rest of
the box.
4. An electrical component as claimed in any preceding claim, which includes a switch
that is activated by the fitting and removal of the cover to the box and that disconnects
the box terminal from the electrical cable when the cover has been removed.
5. An electrical component as claimed in any preceding claim, wherein the contact surface
of the box terminal is located within a recess and wherein the cover terminal is configured
to project into the contact-containing recess when the cover is secured to the box
to establish electrical contact between the box terminal and the cover terminal.
6. An electrical component as claimed in claim 5, wherein the cover terminal has a specific
shape e.g. square, round, rectangular or hexagonal, that is specific for the intended
purpose of the component and wherein the recess that houses the box terminal is correspondingly
shaped so that the cover terminal intended for one purpose cannot fit into the recess
of a box intended for a different purpose.
7. An electrical component as claimed in any preceding claim, wherein the box and cover
include keying projections and recesses that key together and allow the cover and
the box to fit together when intended for the same purpose and prevent the two parts
fitting together when intended for different purposes.
8. An electrical component as claimed in any preceding claim, wherein the box terminal
and the cover terminal are configured to make electrical contact with each other over
a range of separation distances between the open face of the box and the cover.
9. An electrical component as claimed in claim 8, wherein the cover terminal and/or the
box terminal is spring loaded such that the spring urges the terminal concerned into
contact with the other terminal and wherein the spring is in compression when the
cover is secured to the box.
10. An electrical component as claimed in claim 8, wherein the box terminal and the cover
terminal are configured to form a plug-and-socket connection with each other.
11. An electrical component as claimed in any preceding claim, which includes at least
two box terminals and corresponding cover terminals.
12. An electrical component as claimed in claim 11, wherein the cover terminals are arranged
in a pattern or at locations and the box terminals are arranged in a corresponding
configuration or in corresponding locations when the box and the cover are both intended
for a specific purpose, whereby the cover and box terminals can only contact each
other when they are arranged in corresponding configurations or locations.
13. An electrical component as claimed in any preceding claim wherein the box has a substantially
circular cross-section.
14. An electrical component as claimed in any preceding claim which includes a connector,
e.g. a screw, for securing the cover over the front face of the box and/or a further
connector, e.g. a screw, for securing the box within the wall recess.
15. An electrical component as claimed in any preceding claim, in the form of:
- a power socket, a data socket, a television aerial socket, or a CAT-5 cable socket, wherein the cover includes connectors for forming an electrical connection between a plug and the cover terminals or
- an electrical switch having a switching device in the cover.