GB2564684A - Positioning device - Google Patents

Abstract

A positioning device 10 for positioning an electrical socket mounting box (12a, figure 11) relative to a wall to which the box is to be secured, the mounting box having a body portion (14, figure 8) having an inner aperture (15) and a pair of securing points (16a, 16b) on inwardly extending extensions (16c, 16d) for securing an electrical socket assembly, the positioning device comprises a cross-bar 20; one or more first securing members 40a, 40b for securing the cross- bar to the body portion; and a second securing member 50 for securing the body portion relative to a levelling bar (50, figure 15) in which the second securing member comprises a first portion of a slide mount 60 for engagement with a corresponding second portion (62, figure 2) on a levelling bar. As shown in figure 12, the crossbar and level bar may hold the mounting box within a wall 300 during fixing using a filler such as an expanding foam.

Description

POSITIONING DEVICE

The present invention relates to a positioning device to aid in the installation of electrical socket mounting boxes, for example to contain cables, outlets or switches, before wall surface finishing processes such as painting, plastering or similar occur. Additionally, it may provide a safety covering during surface finishing processes to prevent paint, plaster and like materials from encroaching on or into any contained electrical component. Still further, it may provide a way of allowing the electrical cables to be secured safely behind a cover in an electrically live state.

The installation of electrical wiring circuits, controls and outlets during construction involves numerous steps, some of which are contingent upon the performance and completion of other construction tasks. Specifically, the installation of electrical services in a newly-constructed area typically involves several stages and an electrician is often called out on a number of occasions before the final fix and commissioning of the electrical system. A typical process is described below.

Once a wall or partition has been created, an electrician is first called to installs the electrical socket mounting boxes (also known as a pattress, wall box, back box, outlet box, flush socket etc.) and install the electrical components (e.g. cables, switches, outlets, lighting fixtures, etc.), by running the distribution cables from a main power supply to and through the various electrical socket mounting boxes but without making the circuit electrically live. This is often referred to as the first fix.

The installation of the electrical socket mounting boxes is problematic requiring multiple tools (e.g. spirit levels, laser lines, drills etc.) and significant time expenditure to maintain accurate alignment of all the boxes. Specific problems presented include ensuring that the electrical socket mounting box is at the correct position, angle and level, while additionally ensuring that multiple boxes are spaced evenly and are correctly aligned. This is especially difficult where the opening created for the electrical socket mounting boxes has been roughly cut in depth, width, height and shape, and the intention is to fill in the gaps with some type of filler material, e.g. expanding foam, plaster etc. Once this stage is completed the building work such as plastering may continue around the mounting boxes as the circuit is not live so there is no risk of electrocution but plaster and other debris may find its way into the mounting boxes and cover the electrical cables.

The next stage requires the electrician to be recalled to site to perform what is often referred to as the second fix which involves connecting and securing sockets to the electrical cables and to the mounting boxes before completing the circuit to the fuse box and, thus, making the circuit live. Whilst the task is now complete, the electrician has had to make two visits to site and scheduling issues can often delay the completion of the task.

If an electrician is involved in numerous projects or the delay in returning is long, it may be difficult to recall the wiring layout. Since the boxes are now at least partially obscured by the surfaces, the electrician must then spend a considerable amount of time locating the boxes. It is also a common problem that a least one box must be kept live to provide power to the construction workers. This is burdensome to locate and isolate a box and a live box poses a danger to the workers. Therefore, it is further desirable to provide adequate protection and identification of the electrical socket mounting boxes.

A need therefore exists for a simple apparatus for aiding in the accurate positioning and protection of electrical socket mounting boxes, thereby permitting the installation of the electrical cables prior to surface finishing processes and overcoming the existing problems.

An object of this invention is to provide a positioning device to allow the accurate positioning of the electrical socket mounting boxes. It is a further object of the present invention to provide a cover plate for such electrical socket mounting boxes which may be used to protect the contents thereof from plaster and other debris which normally infiltrates the boxes during the building process. It is a still further object of the present invention to provide a cover for use with such electrical mounting boxes which both protects the contents thereof whilst allowing the circuit to be maintained live from the first fix. It is a still further object of the present invention to provide a cover plate arrangement which provides a visual indication that the circuit below is live.

Accordingly, the present invention provide a positioning device for positioning an electrical socket mounting box relative to a wall to which said box is to be secured, said mounting box having a body portion having an inner aperture and a pair of securing points on inwardly extending extensions spaced from each other by a distance for securing an electrical socket assembly to said mounting box, said positioning device comprising: a cross-bar extending along a first longitudinally extending axis and having a length, a first end and a second end and a mid-portion between said first end and said second end and a first side for confronting an electrical socket mounting box and a second side on an opposite side to said first side;

one or more first securing members for securing said cross-bar to said body portion, and a second securing member extending from said second side for securing said body portion relative to a levelling bar; in which the second securing member comprises a first portion of a slide mount for engagement with a corresponding second portion on a levelling bar.

In one arrangement said first portion comprises a male portion and said second portion comprises a female portion. In an alternative arrangement said first portion comprises a female portion and said second portion comprises a male portion.

Advantageously, said first portion of the slide mount comprises an axially extending first dovetail portion on second (outer) side and the corresponding second portion comprises an oppositely shaped axially extending dovetail portion on an inner surface of a levelling bar.

In a preferred arrangement said first dovetail portion comprises a male portion and said second dovetail portion comprises female portion. Alternatively, said first dovetail portion comprises a female portion and said second dovetail portion comprises an axially extending male portion.

Preferably, said first dovetail portion extends along the mid portion of the cross-bar but terminates short of the ends thereof.

Advantageously, the first (inner) side further includes an axially extending inner slide-mount portion shaped to engage and slide along a first portion of a slide mount on a second positioning device.

Preferably, said inner slide mount portion extends along the mid portion of the cross-bar but terminates short of the ends thereof.

Advantageously, the arrangement includes a frictional engagement member on the first (inner) side for frictionally engaging with securing points of an electrical socket mounting box, thereby to secure the positioning device to the electrical socket mounting box.

Preferably, said frictional engagement member comprises confronting inner surfaces of a (vertically extending) slot at each of the first and second ends and wherein said confronting surfaces are spaced from each other by an amount less than a width W of securing points such as to allow the slots to slide over said securing points but to be frictionally engaged therewith.

Advantageously, said cross-bar has an axial width W2 across said first (inner) side less than the total distance between the securing points but greater than the distance between said inwardly extending extensions, thereby to allow the slots to slide over the extensions whilst remaining clear of the securing points.

Preferably, the arrangement includes an axially extending support surface extending from each of the first and second ends of the cross-bar on the first (inner) surface for engagement with an upper or a lower surface of securing point extensions of a socket mounting box.

In one embodiment of the invention the arrangement includes extension guard portions extending vertically from said cross-bar and being shaped to cover an inner aperture of an electrical mounting box.

In an arrangement for high level security, the arrangement may include one or more first securing members for securing said cross-bar to an electrical mounting box, thereby to avoid inadvertent removal thereof.

Advantageously, said cross-bar includes first and second first apertures each extending through said cross-bar from said first side to said second side the first of which being positioned towards said first end and the second of which being positioned towards said second end and said apertures being spaced from each other by said distance D and wherein said one or more first securing members comprise engagement members extending through said first apertures and each including a securing portion for securing to the securing points of said mounting box .

Conveniently, the one or more first securing members comprise a screw and said screw includes a screw thread for engagement in one or more of the securing points of the mounting box.

Preferably, the arrangement includes one or more securing apertures passing through said cross-bar from said first side to said second side for receiving a securing member such as to secure the cross-bar to a surface.

In a particular arrangement of the present invention there is provided a third securing member for securing said cross-bar to a levelling bar extending in a direction transverse to the longitudinal axis.

Advantageously, said third securing member comprised a transversely extending third dovetail portion on the second (outer) side for engagement with a corresponding oppositely shaped axially extending dovetail portion (6fe) on an inner surface of a levelling bar.

Preferably, said third securing member extends through the first portion of the slide-mount.

Advantageously, said positioning device may be transparent.

The arrangement may further include a levelling bar having a first side and a second side and having a length L2 greater than length L 1, a mid-portion of length LI and first and second outer portions axially outward of said mid portion and further including a pair of first apertures extending through said levelling bar for allowing the bar to be secured to a wall and one or more engagement portions for engaging with one or more second securing members extending from said second side for securing said body portion relative to the levelling bar. The cross-bar may form a levelling bar such that multiple cross-bars may be connected to each other, one secured to the electrical box and the others secured to each other such as to provide extensions to the cross-bar that may be secured to the wall to which the electrical boxes are to be installed.

The arrangement may be provided as a kit of parts comprising the components of any one of the items listed in the claims attached hereto.

Aspects of the present invention will now be more particularly described by way of example only with reference to the accompanying drawings in which:

Figure 1, is an isometric front view of a cross-bar according to an aspect of the present invention;

Figure 2, is an isometric rear view of the cross-bar of figure 1;

Figure 3, is an elevational view of the inner surface of the cross-bar shown in figure 1;

Figure 4, is a plan view of the cross-bar shown in figure 1 which omits some of the detail shown in figures 5 and 6;

Figure 5, is a detailed view of a first end of the cross-bar shown in figure 1;

Figure 6, is a detailed view of a second end of the cross-bar shown in figure 1;

Figure 7 is an end elevation of the cross-bar shown in figure 1;

Figure 8 is a frontal view of an electrical mounting box with which the present invention may be used;

Figure 9 is a frontal view of the cross-bar of figure 1 attached to the electrical mounting box of figure 8;

Figure 10 is a frontal view of two electrical mounting boxes joined to each other by means of a cross-bar in each levelling box and a levelling bar extending between the two cross-bars;

Figure 11 is a further front view of the arrangement of figure 10 but with the addition of two further levelling bars, one on each side, such as to allow for the combined assembly to be secured to a wall once levelled,

Figure 12 is a plan view of the arrangement of figure 11;

Figure 13, is a plan view of an alternative arrangement of the cross-bar in figure 1 showing the Addition of a transversely extending dovetail arrangement;

Figure 14, is an elevational view of a transversely extending cross-bar when mounted on a first cross-bar; and

Figure 15 shows a cross-section of the cross-bar 20 and a levelling bar 52.

Referring now to the drawings in general but particularly figures 1 to 4 and 9, an electrical socket mounting box 12 (fig 9) generally has a body portion 14 having an inner aperture 15 and a pair of securing points 16a, 16b on inwardly extending extensions16d, 16e spaced from each other by a distance D for securing an electrical socket assembly to said mounting box

12. Generally, one extension 16e is provided in a fixed manner and one is provided in a mount 16f which allows the extension and, hence, securing point 16b to be varied as required so as to allow for minor re-alignment of any sockets secured thereto. It will be appreciated that the mount 16f will take up some space at the edge of the box 12, as discussed in more detail later herein. A cross-bar 20 extends along a first longitudinally extending axis (X) and has a length (L 1), a first end 22, a second end 24 and a mid-portion 26 between said first end 22 and said second end 24 as well as a first (inner) side 28 for confronting an electrical socket mounting box 12 and a second (outer) side 30 on an opposite side to said first side 28. The cross-bar 20 also includes one or more first securing members shown generally at 40a, 40b and shown in more detail in figures 5 to 7 for securing said cross-bar 20 to the body portion 14 of the mounting box 12. A second securing member shown generally at 50 extends from said second side 30 for securing said body portion 14 relative to a levelling bar 52 shown in detail in figures 10 to 12. The second securing member 50 comprises a first portion of a slide mount 60 for engagement with a corresponding second portion 62 on a levelling bar. Whilst it will be appreciated that one may use any one of a number of forms of slide-mount arrangement between the components, it has been found that the use of sliding dovetail arrangements is particularly useful as they allow for accurate location and security of one within the other whilst also allowing for easy sliding over each other and simple manufacture. Still further, the dovetail arrangement can contribute to the security and accuracy of alignment of the cross-bar 20 and any levelling bar 52, as will be discussed in detail alter herein. When provided as a dovetail arrangement said first portion 60 may comprise a male portion whilst said second portion 62 may comprise a female portion. Alternatively, said first portion 60 may comprise a female portion and said second portion 62 may comprise a male portion. The first dovetail portion may extend along the mid portion 26 of the cross-bar 20 but terminate short of the ends thereof 22, 24 such as to reserve the ends for mechanisms to secure the crossbar 20 to the mounting box 12, as will be discussed in detail later herein.

The first (inner) side 28 may further include an axially extending inner slide-mount portion 80 shaped to engage and slide along a first portion of a slide mount 60 on a second positioning device 10 or an appropriately shaped slide-mount portion on a levelling bar 52. In fact, the provision of inner slide-mount portion 80 converts the cross-bar 20 into a multi-purpose arrangement in which it may also be used as a levelling bar 52 and, thus, one item will be able to perform two functions. The drawings showing multiple cross-bars show them coupled to each other as if one acts as a cross-bar and the other as a levelling bar. It will, however, be appreciated that two separate components may be used as an alternative. When provided, said inner slide mount portion 80 preferably extends along the mid portion 26 of the crossbar 20 but terminates short of the ends thereof 22, 24, thereby to reserve the ends 22, 24 for mechanisms to secure the cross-bar 20 to the mounting box 12, as will be discussed in detail later herein and to ensure the inner slide mount portion 80 does not interfere with the inwardly extending extensions16d, 16e on the mounting box 12. The detail of these arrangements is shown more clearly in figures 5 and 7 discussed later herein.

The ends of the cross-bar may be secured to the mounting box 12 through interaction with the extensions 16d, 16e of the mounting box 12. In one preferred arrangement, the interaction includes a frictional engagement member 100 on the first (inner) side 28 for frictionally engaging with extension portions 16e, 16d of the mounting box 12, thereby to secure the positioning device to the electrical socket mounting box 12 Whilst it will be appreciated that the frictional engagement member 100 may comprise any one of a number of forms, a preferred arrangement comprises confronting inner surfaces 102, 104 of a (vertically) extending slots 106a, 106b at each of the first and second ends 22, 24 in which said confronting surfaces 102, 104 are spaced from each other by an amount less than a width W of securing points 164 16b such as to allow the slots to slide over said extension portions 16e, 16d but to be frictionally engaged therewith. From figures 1 and 2 and other figures in the drawings, it will be appreciated that said cross-bar 20 has an axial width W2 across said first (inner) side 28 less than the total distance between the securing points 16a, 16b but greater than the distance D2 between said inwardly extending extensions 16d, 16e, and the slots 106a, 106b are formed in respective first and second ends 22, 24 such as to allow the slots 106 to slide over outer portions P1, P2 of the extensions 16d, 16e whilst the reduced width W allows the inner side 28 to remain clear of the securing points 16a, 16b which may have burrs around the holes which might cause excessive interference.

Figures 5 to 7 show the arrangement for the frictional engagement in more detail and from which it will be appreciated that confronting surfaces 102,104 define between them extending slots 106 at each of the first and second ends 22, 24. The confronting surfaces 102, 104 may spaced from each other by an amount W+ greater than the width W of the extensions 16d, 16e such as to a provide clearance between themselves and the extensions 16d, 16e when inserted therein or may be spaced from each other by an amount W- which is less than the width W of the securing extension portions 16d, 16e which are to be inserted therein, such as to allow the slots to slide over the extension portions 16e, 16d whilst being in frictional engagement therewith. The latter of these two options is the preferred arrangement as, once the extension portions 16e, 16d are inserted in the slots 106 they will be retained therein until external force is applied to remove them and this may avoid the need for securing screws 42a, 42b or other such devices. The slots 106 may be provided in plain ends with no further support features or, preferably, are provided in ends as shown in figures 5 and 6 which include additional support features for enhanced location. The additional support features include axially extending support surfaces 120a, 120b extending from each end 22, 24 of the crossbar 20 on the first (inner) surface 28 which, in operation, engage with upper or lower surfaces 130a, 130b of extension portions 16e, 16d such as to accurately locate the cross-bar 20 within the mounting box 12.

Figures 5 and 6 also illustrate a further optional arrangement in which the axially extending support surfaces 120a, 120b extend by different amounts such as to allow a gap GL or GS to be formed between ends 120c 120d and the ends 22, 24 of the cross-bar 20 itself. These different gaps allow for the accommodation of the different methods of mounting extension portions 16e, 16d which, as can be seen in figure 8 include one fixed arrangement 16c which projects directly from an inner surface of the mounting box 12 and one floating arrangement 16d which is mounted within a mount 25 which is itself adds an inner protrusion within the mounting box 12 which is accommodated by the greater gap GL.

Other potential features of embodiments of the present invention are best seen in the drawings in general and include first and second first apertures 32a, 32b each extending through said cross-bar 20 from said first side 26 to said second side 28 the first of which 32a being positioned towards said first end 22 and the second of which being positioned towards said second end 24, said apertures 32a, 32b being spaced from each other by said distance D and wherein said one or more first securing members 42a, 42b comprise engagement members 41a, 41b extending through said first apertures 32a, 32b and each including a securing portion 42a, 42b for securing to the securing points 16a, 16b of said mounting box

12. The securing members 42a, 42b may comprise screws and may include screw threads 44 for engagement with one or other of the securing points 16a, 16b which themselves may be threaded or unthreaded holes suitably sized to securely receive the securing members 42a, 42b. If the device is provided as a kit of parts, securing members 42a, 42b may be included as part of that kit.

The positioning device may be provided with one or more securing apertures shown at 200 throughout the drawings but shown most clearly in figures 1 and 2. These apertures 200 extend from the first side 28 to the second side 30 and are used to receive a securing member such as a further screw (not shown) for securing the cross-bar I levelling bar to a wall or other surface in or on which it is desired to secure the mounting box 12. It will be appreciated that one may only need to use apertures 200 provided at the ends of the arrangement and that inner apertures 200 may be used for other purposes. One such use would be the provision of a mains voltage NEON or other such light which could be wired into the mains cables within the mounting box 12 and located within one of the apertures 200 such as to give a strong visual warning that the circuit is live.

A modification of the above arrangement is shown in figure 1 and 13 and comprises a third securing member 600 for securing said cross-bar 20 to a levelling bar extending perpendicular to the longitudinal axis XX of figure 1. In more detail, the arrangement comprises a transversely extending third dovetail portion 600e for engagement with a corresponding oppositely shaped axially extending dovetail 600f on an inner surface 70 of a levelling bar 50 or another cross-bar 20. As shown in figures 1 and 13, dovetail 600f may be formed through the second securing means 60 shown in the figures as a dovetail and, when so provided, will include means defining gaps 610, 620 of sufficient width to accommodate a cross-bar 20 or levelling bar 50 placed therethrough.

Figure 14 illustrates the arrangement where a transversely mounted arrangement is used and from which it will be appreciated that the inner of the two items 700 may be secured to a mounting box 12 (not shown in fig 13) whilst the outer item 800 may be used to secure the assembly to a wall or other surface to which it is desired to secure the mounting box 12.

Whilst it will be appreciated that the above-described cross-bar and levelling bar may be made of any one of a number of materials such as metal, wood or plastic, it has been found that plastic is a preferred material as it will allow the designing-in of a degree of flex or resistance to the insertion of the extension portions 16d, 16e into the slots. This resistance by way of flexing or give will provide a degree of retention of the extension portions 16d, 16e within the slots 100 and, hence, provides the frictional engagement between the cross-bar 20 and the extension portions 16d, 16e desired in one embodiment of the present invention. This frictional engagement may be dispensed with if the cross-bar 20 is otherwise secured to the extension portions 16d, 16e and it will be appreciated that screws 42a, 42b or other such similar devices inserted through holes 32a, 32b and secured within the securing points 16a, 16b or holes within the extension portions 16d, 16e would be a perfectly acceptable option.

Use of the above-discussed arrangement will now be described with reference to the drawings in general but with particular reference to figures 7 and 9 to 12 and with reference to arrows A1 and A2 which provide the directional sequence of installation. The cross-bar 20 is first inserted in the direction of arrow A1 into the mounting box 12 at a position above the extension portions 16d, 16e such as to clear said mounting points and allow the slot 100 to be aligned with the extension portions 16d, 16e before the cross-bar 20 is slid downwardly in the direction of arrow A2 such that the extension portions 16d, 16e enter slots 100. Further pushing of the cross-bar 20 in the direction of arrow A2 will cause the upper surfaces 130a to contact axially extending support surface 120 which, in effect, defines the final position of the cross-bar 20 on the extension portions 16e, 16d. at this position (as shown in figure 5 and 9 and 10 for example) holes 32a, 32b align with the securing point holes 16a, 16b and a screw 44a, 44b may be inserted through the cross-bar 20 and into the extension portions

16d, 16e if so desired. Alternatively, one may rely on the frictional engagement and the contact between support surface 120 and surfaces 130 to retain the cross-bar 20 in the desired position.

Once the cross-bar 20 is securely mounted in the mounting box 12 it may be connected to a levelling bar 52 via the interaction between the second securing member 50 which forms the first portion of a slide mount 60 which engages with a corresponding portion 62 on a levelling bar 52. Whilst the levelling bar 52 may comprise a separate item, it is preferred that the levelling bar 52 comprise a further cross-bar 20 which has provided on a first (inner) side 28 a second portion of a slide mount 62 for engagement with the first portion of the slide-mount 60 provided on outer surface 30 of the cross-bar 20 secured to the mounting box 12. It will be appreciated by adopting this universal dual function of the cross-bar it is possible to eliminate a specifically designed separate levelling bar 52 and simply use multiple cross-bars 20 to perform both functions.

Figure 10 illustrates two cross-bars 20a, 20b secured within respective mounting boxes 12 and a single cross-bar 20c being used to bridge the gap G between them by causing the respective slide-mounts 50, 60 to engage with each other in the manner of inter-engaging sliding portions shown in cross-section in figure 15. It will be appreciated that the levelling bars 52 are simply slid over the cross-bars 20 and may be positioned thereon as and where desired.

As can be seen in figure 11, multiple levelling bars 52 may be slid onto the cross-bars 20 already secured to the mounting boxes 12 and the axial location thereof may be chosen to suit the mounting requirements determined by a user. In the example of figure 11, one levelling bar 52a is shown extending off a first mounting box 12a by a greater amount than a third levelling bar 52c extends off the second mounting box 12b. Such a degree of flexibility in location allows the user to select where the main apertures 200 are positioned and to allow for the alignment thereof with suitable positions on a wall or surface 300 to which the mounting boxes are to be secured. As shown in figure 12, the mounting boxes 12 may be recessed into holes 310 formed in the wall 300 and, hence, the levelling bars 52 may be used to ensure each mounting box 12 is level relative to each other whilst also being level relative to a levelling line L (fig 11) such as may be provided by a laser level (not shown). Once the levelling bars 52 and cross-bars 20 are level as required, the user simply secures the entire assembly to the wall 300 by means of conventional screws shown diagrammatically at 400 which are passed into holes 200 and then screwed into the wall itself 300. Any gaps between the mounting boxes 12 and the recesses 310 may be filled with filler or expanding foam such as to secure the boxes in position. Once the filler or foam has set the levelling bars 52 may be removed by sliding them axially such as to disengage them from the cross-bars 20 and the cross-bars 20 may be removed by reversing the motion described with reference to arrows A1 and A2 of figure 5. Any screws 44 that may have been used should be removed 5 before the cross-bars are disengaged from the mounting boxes.

It will be appreciated that the above-discussed cross-bars 20 and levelling bars 52 may be re-used again and again. It will also be appreciated that it is sometimes difficult to find space laterally to each side of the position where it is desired to locate a mounting box 12 and, in io such circumstances alternative mounting arrangements may be necessary. One such alternative mounting arrangement is shown in figure 14 in which the cross-bar 20 is secured to the mounting box 12 in the manner described above but the levelling bar 52 is connected by engagement with the transverse third securing member 600 best seen in figure 1. This arrangement allows the user to secure the levelling bar 52 to the wall via vertically displaced 15 screws (not shown) passing through vertically spaced apertures 200.

Claims (24)

1. A positioning device (10) for positioning an electrical socket mounting box (12) relative to a wall to which said box (12) is to be secured, said mounting box (12) having a body portion (14) having an inner aperture (15) and a pair of securing points (16a, 16b) on inwardly extending extensions (16d, 16e) spaced from each other by a distance (D) for securing an electrical socket assembly to said mounting box (12), said positioning device (10) comprising:

a. A cross-bar (20) extending along a first longitudinally extending axis (X) and having a length (L1), a first end (22) and a second end (24) and a mid-portion (26) between said first end (22) and said second end (24) and a first side (28) for confronting an electrical socket mounting box (12) and a second side (30) on an opposite side to said first side (28);

b. one or more first securing members (40a, 40b) for securing said cross-bar (20) to said body portion (14); and

c. a second securing member (50) extending from said second side (30) for securing said body portion (14) relative to a levelling bar (50);

characterised in that the second securing member (50) comprises a first portion of a slide mount (60) for engagement with a corresponding second portion (62) on a levelling bar.

2. A positioning device (10) as claimed in claim 1, wherein said first portion (60) comprises a male portion and said second portion (62) comprises a female portion.

3. A positioning device (10) as claimed in claim 1, wherein said first portion (60) comprises a female portion and said second portion (62) comprises a male portion.

4. A positioning device (10) as claimed in any one of claims 1 to 3, wherein said first portion of the slide mount (60) comprises an axially extending first dovetail portion (60a) on second (outer) side (30) and the corresponding second portion (62) comprises an oppositely shaped axially extending dovetail portion (62b) on an inner surface (70) of a levelling bar (50).

5. A positioning device (10) as claimed in claim 4, wherein said first dovetail portion (60a) comprises a male portion and said second dovetail portion (62) comprises female portion (62b).

6. A positioning device (10) as claimed in claim 4, wherein said first dovetail portion (60a) comprises a female portion and said second dovetail portion (62) comprises an axially extending male portion (62b).

7. A positioning device (10) as claimed in any one of claims 1 to 6, wherein said first dovetail portion extends along the mid portion (26) of the cross-bar (20) but terminates short of the ends thereof (22, 24).

8. A positioning device (10) as claimed in any one of claims 1 to7, wherein the first (inner) side (28) further includes an axially extending inner slide-mount portion (80) shaped to engage and slide along a first portion of a slide mount (60) on a second positioning device (10).

9. A positioning device as claimed in claim 8, wherein said inner slide mount portion (80) extends along the mid portion (26) of the cross-bar (20) but terminates short of the ends thereof (22, 24).

10. A positioning device (10) as claimed in any one of claims 1 to 9, and including a frictional engagement member (100) on the first (inner) side (28) for frictionally engaging with securing points (16a, 16b) of an electrical socket mounting box (12), thereby to secure the positioning device to the electrical socket mounting box (12).

11. A positioning device (10) as claimed in claim 10, wherein said frictional engagement member (100) comprises confronting inner surfaces (102, 104) of a vertically extending slot (106) at each of the first and second ends (22, 24) and wherein said confronting surfaces (102, 104) are spaced from each other by an amount less than a width W of securing points (16a, 16b) such as to allow the slots to slide over said securing points (16a, 16b) but to be frictionally engaged therewith.

12. A positioning device (10) as claimed in claim 11, wherein said cross-bar (20) has an axial width W2 across said first (inner) side (28) less than the total distance between the securing points (16a, 16b) but greater than the distance between said inwardly extending extensions (16d, 16e), thereby to allow the slots (106) to slide over the extensions (16d, 16e) whilst remaining clear of the securing points (16a, 16b).

13. A positioning device (10) as claimed in any one of claims 1 to 12 and including an axially extending support surface (120) extending from each of the first and second ends (22, 24) of the cross-bar (20) on the first (inner) surface 28 for engagement with an upper or a lower surface (130a, 130b) of securing point extensions (16d, 16e) of a socket mounting box (12).

14. A positioning device (10) as claimed in any one of claims 1 to 13 and including extension guard portions (140a, 140b) extending vertically from said cross-bar (20) and being shaped to cover an inner aperture (15) of an electrical mounting box (12).

15. A positioning device (10) as claimed in any one of claims 1 to 14 and including one or more first securing members (40a, 40b) for securing said cross-bar (20) to an electrical mounting box (12).

16. A positioning device (10) as claimed in claim 15, wherein said cross-bar (20) includes first and second first apertures (32a, 32b) each extending through said cross-bar (20) from said first side (26) to said second side (28) the first of which (32a) being positioned towards said first end (22) and the second of which being positioned towards said second end (24) and said apertures (32a, 32b) being spaced from each other by said distance D and wherein said one or more first securing members (40a, 40b) comprise engagement members (41a, 41b) extending through said first apertures (32a, 32b) and each including a securing portion (42a, 42b) for securing to the securing points (16a, 16b) of said mounting box (12).

17. A positioning device (10) as claimed in claim 16, wherein the one or more first securing members (40a, 40b) comprise a screw and said screw includes a screw thread (44) for engagement in one or more of the securing points (16a, 16b) of the mounting box (12).

18. A positioning device (10) as claimed in any one of claims 1 to 15 and including one or more securing apertures (200) passing through said cross-bar (20) from said first side (28) to said second side (30) for receiving a securing member such as to secure the cross-bar (200) to a surface.

19. A positioning device (10) as claimed in any one of claims 1 to 16 and including a third securing member (600) for securing said cross-bar (20) to a levelling bar extending in a direction transverse to the longitudinal axis (X).

20. A positioning device (10) as claimed in claim 17, wherein said third securing member (600) comprises a transversely extending third dovetail portion (60e) on the second (outer) side (30) for engagement with a corresponding oppositely shaped axially extending dovetail portion (6fe) on an inner surface (70) of a levelling bar (50).

21. A positioning device (10) as claimed in claim 17 or 18, wherein said third securing member (600) extends through the first portion of the slide-mount (60).

22. A positioning device (10) as claimed in claim 6, wherein said positioning device (10) is transparent.

23. A positioning device (10) as claimed in any one of claims 1 to 10 and including a levelling bar (50).

24. A kit of parts comprising the components of any one of the preceding claims.