GB2286929A

GB2286929A - An electrical accessory mounting

Info

Publication number: GB2286929A
Application number: GB9500834A
Authority: GB
Inventors: David Michael Jeffrey
Original assignee: Caradon MK Electric Ltd
Current assignee: Caradon MK Electric Ltd
Priority date: 1994-02-25
Filing date: 1995-01-17
Publication date: 1995-08-30
Anticipated expiration: 2015-01-17
Also published as: GB2286930B; GB2286929B; GB9500834D0; GB9403607D0; GB2286930A; GB9500838D0

Abstract

An electrical accessory mounting (200) is fixed in between a first and second part (302, 208) of an electrical accessory such as a switch or socket, the mounting being sealingly engaged with the first and second parts e.g. by gaskets (322, 322'), and having means enabling the mounting to be secured to a mounting surface e.g. by screws (280), with the accessory partially recessed. The mounting is hollow so as to allow communication between the first and second parts. Alternative securing means allow the accessory to project by different amounts from the mounting surface. An annular cover plate (130) may be provided. <IMAGE>

Description

AN ELECTRICAL ACCESSORY MOUNTING The present invention relates to mountings for electrical accessories.

Electrical accessories, for example switches and socket outlets, for fixing on a surface inside a building are well known. It is also known to construct an electrical accessory so that it is sealed to exclude moisture and dust, so that it may safely be used in external and other locations where normal accessories would present a safety hazard. Known electrical accessories may be constructed to be mounted to one type of mounting box for fixing on the surface and to be mounted to a second type of mounting box for fixing flush with the surface and will perform entirely satisfactorily with either mounting box. Where electrical accessories constructed to exclude moisture and dust it is important for the integrity of the accessory to be maintained. Hence it is customary to only manufacture these electrical accessories in a form arranged for fixing on a surface. This is not always desirable, since such electrical accessories tend to be bulky and protrude more than a normal electrical accessory. Hence they may be more prone to accidental damage, and may be visually intrusive.

It is an object of the present invention to provide means whereby electrical accessories, which are suitable for excluding moisture and dust, to be mounted partially recessed manner below a surrounding surface.

An electrical accessory mounting according to one aspect of the invention is securable between a first and a second part of an electrical accessory, and comprises a first sealing surface engageable with said first part, a second sealing surface engageable with said second part, securing means enabling the mounting to be secured to a mounting surface, the mounting having a hollow interior so as to allow communication between the first and second parts.

An electrical accessory is provided according to another aspect of the invention having a mounting as described above in which the mounting is secured between the two parts of the accessory.

An embodiment according to this invention will enable an installer to substantially reduce the amount that an electrical accessory designed for surface fixing protrudes above the surface it is fixed onto. In particular where the surface is a wall made of brick, block, or board, or other substrate that may be subsequently be finished with conventional rendering, plastering, or tiling or a combination of these, a mounting for securing in-between the front and rear parts of a complete surface mounted electrical accessory will enable the accessory to be mounted in a recess or hole such that only part of the accessory is visible above the surface. A particular embodiment is designed to fit in-between the front and rear parts of a complete surface mounted electrical accessory that is constructed such that it excludes moisture and dust, so that it may safely be used in external and other locations where normal accessories would present a safety hazard. This embodiment enables the exclusion features of the standard surface mounted electrical accessory to remain intact when it is installed in a recessed manner. For accessories such as socket outlets that include a lid which is hinged to allow the lid to be opened to permit the insertion of a plug into the socket it is necessary that sufficient of the accessory protrudes from the surrounding finished surface to enable the normal operation of the lid.

To enable this embodiment to be secured to the substrate surface, securing means are provided which comprises a lateral extension on at least two opposed lateral sides of the mounting. In a particular embodiment these lateral extensions provide lugs with holes suitable for using with ordinary countersunk screws. The lateral extensions may extend on all sides, or may extend from a lateral projection extending around the periphery of the external wall surface of the mounting. The mounting being hollow permits an electrical cable entering in the rear part of the electrical accessory to be connected to for example a switch or socket fitted within the front part of the electrical accessory.

It is particularly important when electrical accessories are installed into clean or sterile areas, such as kitchens, and places where food is prepared or processed, or hospitals, that there are no crevices that may harbour dirt or bacteria or similar. With known electrical accessories problems arise as it is hazardous to clean them by washing them down with water. With existing electrical accessories designed for use in areas subject to hosing down with water it is difficult to install them to avoid dirt traps. It is an advantage of an embodiment of this invention that not only is the aesthetic appearance of the sealed electrical accessory improved by being recessed into the mounting surface, but it is far easier to ensure that no dirt traps exist when the product is installed. An annular cover plate may also be used and may be retained in position by beads of sealant such as silicone rubber or epoxy resin or other material that has a surface suitable for cleaning and good adhesive properties.

In an embodiment of the invention optional spacers are included to allow the installer to vary the amount that the electrical accessory protrudes above the surrounding finished surface by placing the spacers between the fixing lugs extending from the mounting and the substrate surface to which the lugs are secured.

The installer is expected to fold the most appropriate thickness spacer under the lug if required at the time of installation. If desired it is possible for the installer to break the spacer away from the lug instead, this would be necessary for example should the installer wish to use both spacers between the lug and the substrate surface.

When a spacer is folded under the lug, the lug may be secured firmly against the substrate surface using fixing means such as screws, such that the accessory protrudes more than it would if the spacer had not been placed under the lug.

An embodiment of the invention will now be described with reference to the accompanying drawings in which: Figure 1 shows a perspective view of a mounting for securing in-between a front part (not shown in this Fig.) and a rear part of a complete surface mounted electrical accessory to enable the accessory to be mounted in a recess or hole in a substrate surface that will be subsequently be finished with conventional rendering, plastering, or tiling or a combination of these; and Figure 1A shows an detail of a fixing lug of the mounting shown in Fig. 1 with the deeper one of the two spacers folded under the fixing lug; and Figure 2 shows a partly sectioned side view of the mounting shown in Figure 1 fitted in-between the front and rear parts of a complete surface mounted electrical accessory the whole mounted in a recess or hole in a substrate surface that has been finished with a combination of conventional rendering, and or plastering, and or tiling, the section showing in particular one of the spacers fitted between the fixing lug and the substrate surface; and Figure 3 shows a similar part section to that shown in Fig. 2, with the cover plate shown in Fig. 4 fitted around the electrical accessory; and Figure 4 shows a perspective view of a cover plate suitable for fixing around the electrical accessory fitted as shown in Fig. 3 ; and Figure 5 shows a partly sectioned view through an alternative embodiment of the mounting to that shown in Fig. 1, but with different thicknesses of plaster or render and top finish or tile, the alternative mounting being shown fitted to a rear part of an electrical accessory; and Figure 6 shows the same alternative embodiment of the mounting as shown in Fig. 5, but with a different thicknesses of plaster or render and top finish or tile; and Figure 7 shows side view of a further alternative embodiment of the mounting mounted in a recess or hole in a relatively thin mounting surface, such as plasterboard or plywood.

Figure 1 shows a perspective view of a mounting 200 for fixing in-between a front part (not shown) and a rear part 302 of a complete surface mounted electrical accessory to enable the accessory to be mounted partly recessed in a recess or hole in a substrate surface (not shown) that will be subsequently be finished with conventional rendering, plastering, or tiling or a combination of these. The flange member 200 comprises four walls 202 forming the sides of a short rectangular tubular part, incorporating bosses 204 in each of the four corners with holes 206 to take extension studs 320 (only one shown) to enable the rear part 302 to be fitted to the rear face 208 of the tubular part, and to enable the front part of an electrical accessory to be fitted to the front face 210 of the tubular part. Each of the extension studs 320 has an end with a male thread 324 and a headed end with a female thread 328, a shoulder 332, and a slot 330 suitable for a screwdriver. The male threaded end 324 passes through hole 206 and hole 328 in a gasket 322 and screws into the female thread in hole 326 in the rear part 302. The rear part 302 has a front face 310 which is provided with an upstanding continuous wall 311 to provide a location for the gasket 322 at the joint with the mounting 200. The rear face 208 has a similar but complementary upstanding continuous wall (not visible in this Fig.) which co-operates with a step 330 that is continuous around the periphery of the gasket 322. A flange 212 extends around the four walls and has four fixing lugs 214 (only three visible) each with a screw hole 216 for fixing the mounting to the substrate surface. The screw holes 216 may be provided as shown with a countersunk portion to facilitate the use of countersunk fixing screws (not shown in this Fig.). Each of the four fixing lugs 214 is identically provided with two spacers 218 and 220 of two different heights, which are hingedly connected to the fixing lugs. Two opposed walls are provided with provision for making a drain hole 222 and corresponding internal features 224 to ensure that moisture that may enter the accessory may be safely drained out at the bottom of the accessory when it is installed on a vertical surface. A rearward facing upstand 226 is provided to ensure that the rear part 302 of the electrical accessory is correctly orientated when it is fixed to the rear face 208, this ensures that the gasket 322 maintains its waterproof seal at the joint. The rear part has four holes suitable for conduit entry which are each sealed against moisture entry by a removable blanking plug 350.

Figure 1A shows a detail of one of the fixing lugs as shown above in Fig. 1, but with the spacer 220 hingedly folded under the fixing lug 214. A hinge 215 is provided to permit the spacer to be hinged. A similar hinge 217 is provided to also attach the other spacer 218 to the fixing lug.

Similarly spacer 218 may be hingedly folded under the fixing lug 214 instead of spacer 220. The two types of spacers are of different heights to enable the installer to ensure that the electrical accessory protrudes from the surface by the correct amount.

Figure 2 shows the mounting 200 shown in Figure 1 fitted in-between the front part 304 and rear part 302 of a complete surface mounted electrical accessory which in this instance is a socket outlet, but could be a switch or a terminal box or other accessory, the whole mounted in a recess or hole 502 in a substrate surface 504 that has been finished with a combination of conventional rendering 506, and plastering 508. Spacer 220 is shown fitted between lug 214 and the substrate surface 504, to provide the correct protrusion above the finished surface 510 of the plaster to enable lid 306 to hinge open, and for drain 222 (not visible in this fig.) to function if required. Four or perhaps two ordinary countersunk head screws 280 (only one of which is shown in this figure) are each screwed into a suitable wall plug 282 to secure the respective fixing lugs to the substrate 503. A conduit 600 is buried in the substrate 503, and terminated with a suitable fitting 602 to provide a concealed means of connecting electrical cables (not shown) to the electrical accessory. One of the blanking plugs 350 shown in Fig. 1 is removed to enable fitting 602 to be inserted. Gasket 322 is shown providing the seal between the rear part 302 and the flange member 200, and another similar gasket 322' is shown providing the seal between the front part 304 and the flange member 200.

Figure 3 shows the same complete surface mounted electrical accessory 300 as shown in Figure 2 fitted with the flange member 200, both being partly sectioned to show the extension stud 320 screwed into the female threaded hole 326 in the rear part, and clamping the flange member by means of shoulder 332 which acts against a corresponding feature inside hole 206. The front part is clamped against the flange member by the screw 308 which would normally be used to secure the front part to the rear part. Upstanding continuous wall 311 on the rear part and 211 on the flange part co-operate with the corresponding features 312 and 313 both of which are also upstanding continuous walls to ensure good location of the gaskets 322 and 322' and a good seal against the ingress of moisture and dust.

Sealing is also improved by increasing the rigidity of the parts, and flange 212 advantageously increases the rigidity of the mounting to resist distortion arising from securing to uneven surfaces.

Figure 3 particularly shows the joint between the flange member and the plastering covered by a thin annular rectangular cover plate 130 as shown in Figure 4. The cover plate is secured in place by two beads 132 and 134 of an adhesive sealant such as cold setting silicone rubber sealant. The beads 132 and 134 of sealant provide a seal between the finished surface 510 and the electrical accessory 300 ensuring that there is no gap or crevice that might harbour bacteria or other dirt. Alternatively the joint between the flange member and the plastering could be covered by a flexible seal (not shown) which could form part of the gasket 322' extending around the external periphery of the gasket, and formed to press and seal against the finished surface 510.

Figure 4 shows a perspective view of the thin annular cover plate 130. The central aperture 136 is shaped to allow the cover plate to fit neatly around a complete surface mounted electrical accessory when it is mounted partially recessed.

The cover plate 130 is also provided with four cut-outs 138 (only two visible) which correspond to the positions of the drain holes 222 if they are required. The cut-outs ensure that if the drain holes are in use, any moisture within the accessory is able to drain away.

Figures 5 and 6 show an alternative arrangement for altering the protrusion of the electrical accessory above the substrate surface 504 to ensure that the front part of the electrical accessory (not shown in these figures) is the correct height above the surrounding finished surface 510. The alternative flange member 700 is similar to the flange member 200, in that it is designed to fit between the front part (not shown in these figures) and rear part 302 of a complete surface mounted electrical accessory. The alternative flange member 700 is provided with a series of ratchet teeth 702 that engage with matching teeth formed in the inner periphery of an annular fixing flange 712. Flange 712 is provided with a plurality of fixing holes 716 to enable the flange to be fixed to the substrate surface 504 with suitable screws such as the countersunk screws 780. In operation the hole 502' is made in the substrate and the fixing flange is then positioned over the hole and secured in place using the fixing screws 780, the ratchet teeth 702 are such that the tubular part 720 of the alternative flange member may be pushed into the hole in the direction of arrow P until the desired protrusion of the electrical accessory has been achieved.

An electrical accessory mounting as claimed in Claims 1 to 3, wherein the securing means further comprises on at least two opposed lateral sides of the mounting a sprung detent spaced from the external surface of the mounting.

Figure 7 shows an alternative embodiment of the invention comprising an electrical accessory mounting 800 wherein the securing means further comprises on at least two opposed lateral sides of the mounting a sprung detent 810 spaced from the external surface 802 of the mounting. The mounting 800 is shown with a rear part 830 of an electrical accessory secured to it and a sealing gasket 832 fitted between the sealing surfaces. A front part of the electrical accessory would be secured to the sealing surface 834. The sprung detent 810 is sprung in the direction of arrow S away from the mounting, so that it either engages with the sides of the deep hole, or if the mounting is fitted to a thin fixing surface such as that shown in Fig. 7, the sprung detent may engage the rear edge 820 of the hole 822. The sprung detent is arranged such that the force required to insert the mounting into the hole is substantially low, but the force required to remove the mounting from the hole is substantially above that which an electrical accessory fitted to the mounting would be subject to in service. The sprung detent is attached to the side of the mounting by a rivet 804. The flange 806 extending around the mounting rests against the outside surface 824 of the mounting surface 826 which could be for example plywood, or plasterboard used in a dry wall partition. Such a sprung detent securing means enables very fast installation of the mounting in such a mounting surface, and the flange 806 covers the gap around the mounting eliminating the need for any additional finishing.

Claims

1. An electrical accessory mounting securable between first and second parts of an electrical accessory, comprising a first sealing surface engageable with said first part, a second sealing surface engageable with said second part, securing means enabling the mounting to be secured to a mounting surface, the mounting having a hollow interior so as to allow communication between the first and second parts.

2. An electrical accessory mounting as claimed in Claim 1, wherein the securing means comprises a lateral extension extending on at least two opposed lateral sides of the mounting.

3. An electrical accessory mounting as claimed in Claim 2, wherein the lateral extension extends around all sides of the mounting.

4. An electrical accessory mounting as claimed in Claim 2 or 3, wherein the lateral extension has slots or holes to receive a screw.

5. An electrical accessory mounting as claimed in Claims 2 to 3, wherein the securing means further comprises on at least two opposed lateral sides of the mounting a sprung detent spaced from the lateral extension in a direction between the sealing surfaces.

6. An electrical accessory mounting as claimed in Claim 1 wherein the securing means comprises a plate engageable with the lateral sides of the mounting.

7. An electrical accessory mounting as claimed in Claim 6 wherein the plate is adjustably engageable with the lateral sides of the mounting.

8. An electrical accessory mounting as claimed in Claim 7 where the lateral sides of the mounting and plate engage with a tooth and ratchet arrangement.

9. An electrical accessory mounting as claimed in Claims 1 to 4, wherein the securing means is provided with spacers that may be placed between a rear face of the mounting flange and the surface.

10. An electrical accessory mounting as claimed in Claim 9, wherein the spacers are attached to the securing means in a manner such that without separating them from the securing means they may or may not be placed between a rear face of the securing means and the surface.

11. An electrical accessory mounting as claimed in Claim 10, wherein the spacers are arranged so that when they are placed between the rear face of the securing means and the surface, they are retained in position by a fixing means.

12. An electrical accessory mounting as claimed in any of the preceding Claims wherein means is provided for drainage of moisture from within the hollow interior.

13. An electrical accessory mounting as claimed in any of the preceding Claims wherein a receiving hole is provided within the hollow interior to receive fixing means extending between the first and the second parts.

14. An electrical accessory mounting substantially as described with reference to Figures 1 to 4 of the accompanying drawings.

15. An electrical accessory mounting substantially as described with reference to Figures 5 and 6 of the accompanying drawings.

16. An electrical accessory mounting substantially as described with reference to Figure 7 of the accompanying drawing.

17. An electrical accessory having a mounting as claimed in any one of Claims 1 to 16, wherein the mounting is secured between a first part and a second part of the electrical accessory, and the electrical accessory and mounting is sealed.

18. An electrical accessory having a mounting as claimed in any one of Claims 1 to 16, and an electrical accessory as claimed in Claim 17, wherein the electrical accessory mounting is covered by a finishing layer which is applied to the mounting surface subsequent to the securing of the electrical accessory mounting to the mounting surface.

19. An electrical accessory having a mounting as claimed in any one of Claims 1 to 16, and an electrical accessory as claimed in Claims 17 or 18, wherein a cover plate is provided to surround the electrical accessory so as to cover a gap between an exterior surface of the accessory or mounting and a surrounding surface.

20. An electrical accessory having a mounting as claimed in any one of Claims 1 to 16, and an electrical accessory as claimed in any one of Claims 17 to 19, wherein the electrical accessory may be operated in a similar manner when secured to the electrical accessory mounting as it would be operated if the electrical accessory were mounted directly on a surface.

21. An electrical accessory substantially as described with reference to Figures 1 to 4 of the accompanying drawings.

22. An electrical accessory substantially as described with reference to Figures 5 and 6 of the accompanying drawings.

23. An electrical accessory substantially as described with reference to Figure 7 of the accompanying drawings.