GB2396062A

GB2396062A - Electrical device support plate

Info

Publication number: GB2396062A
Application number: GB0325136A
Authority: GB
Inventors: Maol Cazals; Marcel Daccord
Original assignee: Legrand SA; Legrand SNC
Current assignee: Legrand SA; Legrand SNC
Priority date: 2002-10-28
Filing date: 2003-10-28
Publication date: 2004-06-09
Anticipated expiration: 2023-10-28
Also published as: FR2846476A1; FR2846476B1; GB2396062B; GB0325136D0

Abstract

An electrical device includes a support plate 12 and a box 36 adapted to receive the support plate 12 which carries an interengaging rim 18 that projects from the rear face, extends along the edge portion of the support plate 12, and is adapted to bear against inside faces 40 of walls of the box 36 to fasten the support plate 12 to the box 36. The interengaging rim 18 of the support plate 12 may be removable. The interengaging rim 18 may be connected to the support plate 12 by fragile means which may be broken so as to remove the interengaging rim 18 from the support plate 12.

Description

GB 2396062 A continuation (74) Agent and/or Address for Service: D Young &

Co 21 New Fetter Lane, LONDON, EC4A 1 DA, United Kingdom

SPECIFICATION

An electrical device support plate 5 The present invention relates generally to electrical devices and in particular to an electrical device including a box adapted to receive a support plate having a rear face.

The invention also relates to a support plate for a 10 device mechanism especially adapted to the electrical device previously cited.

The devices concerned are in particular socket outlets or switches whose boxes can be built into a wall or project from the wall.

15 Electrical devices such as those previously cited whose device mechanism mounted on the support plate is accommodated in the box and whose front face is closed by an embellisher front plate exposing the actuation portion of the mechanism are already known in the art.

20 The front plate is usually held in a fixed position on the box projecting from a wall or built into the wall by fixing screws.

When the front plate is mounted on a projecting box, which is generally of rectangular parallelepiped 25 shape, it is necessary, essentially for safety reasons, for the edge portions of the box to extend continuously and edge to edge the edge portions of the front plate so that no edge portion projects relative to another and forms a sharp edge.

30 To this end, it has been envisaged to provide a rebate in the edge portions of the lateral walls of the box and to form the edge portions of the front plate in such a fashion as to obtain a cover, the thickness of the rebate substantially corresponding to the thickness of 35 the shaped edge portions of the front plate.

À e. À :: .: I a -, Accordingly, the edge portions of the front plate lie inside the rebate on the box and the edge surface of the edge portions abuts against the shoulder on the lateral walls of the box formed by the rebate, which 5 leaves no projecting sharp edges. Moreover, the front plate fits perfectly onto the box.

However, providing the rebate requires an additional step in the fabrication process of the box, which significantly adds to the overall cost of 10 manufacture of the corresponding electrical device.

To alleviate the drawbacks of the prior art cited

above, the present invention proposes an electrical device including a support plate and a box adapted to receive the support plate, which has a rear face and 15 carries an interengaging rim that projects from the rear face, extends along the edge portion of the support plate, and is adapted to bear against inside faces of walls of the box to fasten the support plate to the box.

Accordingly, thanks to the advantageous feature of 20 the invention that resides in the connection between the electrical device support plate and the inside faces of the walls of the box, which retains the support plate in a fixed position relative to the box in a direction substantially parallel to the support plate, the front 25 plate, which can be fastened to or integral with the support plate, is also retained in a fixed position relative to the box in the same direction.

The electrical device preferably includes a front plate fastened to or integral with the support plate, an 30 edge portion of the front plate extending along the interengaging rim and being adapted to be positioned facing an edge surface of the edge portion of the box.

As a result, the front plate is first fitted edge to edge with the box so that the edge portion of the 35 front plate covers the edge surface of the edge portion

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I t I I À. Bt C$' of the box without it being necessary to fasten them together or to form a rebate in the edge portion of the box Thus there is no sharp edge on the outside face of the box closed by the front plate.

5 In a particularly advantageous embodiment of the invention, the edge portion of the front plate carries a rim bearing against at least a portion of the interengaging rim of the support plate and an edge surface of the rim of the front plate is adapted to bear 10 against the edge surface of the edge portion of the box when the support plate and the box are fastened together.

Accordingly, thanks to the rim on the front plate, which generally forms therewith a rounded surface, and which bears against a portion of the build-in edge 15 portion, the support plate and the front plate can be fitted to the box in such a manner that the edge surface of the rim of the front plate can bear against the edge surface of the edge portion of the box. As a result, the edge surfaces of the edge portion of the box and the 20 front plate bear against each other and do not expose any sharp edge.

In one particular embodiment of the invention, the box and the front plate are made of metal.

A material of this kind is readily deformable so 25 that the rim of the front plate is fabricated without difficulty, for example by pressing a flat plate.

The support plate is advantageously moulded in one piece from a plastics material. Thus the support plate is fabricated at an advantageous cost if it is mass 30 produced.

The present invention also proposes a support plate for an electrical device mechanism and having a rear face and an interengaging rim that is removable from the support plate and projects from the rear face.

35 Thus the support plate constitutes a standard

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plate, which is not only adapted to be mounted on a projecting box thanks to the interengaging rim, but is also adapted to be installed directly in a box built into a wall, thanks to the removable nature of the 5 interengaging rim. It suffices for the installer to remove the interengaging rim of the support plate, to prevent the latter from impeding application of the edge portion of the front plate against the perimeter of the built-in box.

10 The interengaging rim can be removed from the support plate by a simple mechanical operation during installation of the electrical installation.

It is therefore clear that only one type of support plate is needed for both types of box (built-in or 15 projecting), and that this reduces the fabrication costs of the support plate.

In a preferred embodiment, said support plate includes a central portion and a peripheral portion from which the interengaging rim projects, substantially 20 perpendicularly to said plane.

Thus the central portion, which is generally plane, is adapted to receive the front plate, which generally also has a plane portion The front plate also bears against the peripheral portion from which the build-in 25 edge portion projects.

It is particularly advantageous if the peripheral portion and the central portion are connected together by fragile connecting means adapted to be fractured to separate the peripheral portion from the central portion 30 to remove the interengaging rim.

Thanks to this feature, the interengaging rim is removable by fracturing the fragile connecting means to separate the peripheral portion from the central portion.

In one particularly advantageous embodiment, the 35 peripheral portion has an inside edge portion and the

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central portion has an outside edge portion, the edge portions face each other, and the fragile connecting means comprise a plurality of connecting lugs distributed along the inside edge portion and the outside edge 5 portion, which face each other.

As a result, when the connecting lugs connect the respective edge portions of the central portion and the peripheral portion, these two portions are fastened together and the support plate forms a single component.

10 Thus the peripheral portion and the central portion become independent of each other when the connecting lugs are fractured.

The inside edge portion and the outside edge portion advantageously each have a respective plurality 15 of notches facing each other and the connecting lugs extend into the notches and have drive means adapted to fracture them.

The notches therefore accommodate connecting lugs with relatively large dimensions to incorporate drive 20 means.

Thanks to the drive means, the connecting lugs are easily fractured by means of ordinary tools adapted to co-operate with the drive means.

In a different embodiment, the inside edge portion 25 and the outside edge portion have a plurality of connecting lugs connecting the two inside and outside edge portions and there is provided for each lug a tongue that is attached either to the outside edge portion or to the inside edge portion and which extends either towards 30 the inside edge portion or towards the outside edge portion, respectively, and over the connecting lug and the other edge portion.

Thus a tool can be inserted into the space between the tongue and the edge portion that it surmounts and 35 apply leverage against the tongue to rupture the

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.*..e. connecting lug.

It is particularly advantageous if the device support plate is moulded in one piece with the interengaging rim from a plastics material.

5 Thus, thanks to this feature, not only is the electrical device support plate produced at advantageous cost, but the connecting lugs are easily produced by modifying their section when making the mould. An appropriate choice of plastics materials, for example 10 polyamide, obtains connecting lugs that are easy to fracture. Other features and advantages of the invention will emerge from a reading of the following description of

particular embodiments of the invention, given by way of 15 illustrative but nonlimiting example and with reference to the appended drawings, in which: - figure 1 is a diagrammatic perspective view showing a component of a first embodiment of the electrical device according to the invention; 20 - figure 2 is a diagrammatic exploded perspective view of the component shown in figure 1; - figure 3 is a diagrammatic view in vertical section of the electrical device according to the invention; 25 - figure 4 is a diagrammatic perspective view showing a second embodiment of the component represented in figure It - figure 5 is a diagrammatic view in vertical section of the electrical device including the second 30 embodiment of the component; - figure 6 is a diagrammatic view of details of figure 1 for a first variant; - figure 7 is a diagrammatic view of details of figure 1 for a second variant; and 35 - figure 8 is a diagrammatic view of details of

À À. e À..e eae figure 1 for a third variant.

Figure 1 shows the rear of a portion of an electrical device according to the invention that includes a front plate 10, a support plate 12, and a 5 device mechanism 14 retained in a fixed position on the support plate 12 by fixing screws, not shown. Here the electrical device is a socket outlet.

Figure 2 shows the front plate 10, the support plate 12, and the device mechanism 14 separated from each 10 other.

The support plate 12 has a rear face 16 and an interengaging rim 18 that projects from the rear face 16 and runs along the edge portion 20 of the support plate 12. 15 The interengaging rim 18 extends continuously along and perpendicularly to the edge portion 20 of the support plate 12. It therefore surrounds the support plate 12 completely and defines a closed surface.

The device mechanism 14 mounted on the support 20 plate 12 has a front face that is pressed against the rear face 16 of the support plate 12.

The support plate 12 includes three orifices 22 adapted to receive the pins of a plug, which can thereby access the connecting terminals of the device mechanism 25 14. The support plate 12 also includes an opening 26 through which passes the actuation portion of the device mechanism 14, here consisting of a rocker switch button (see figure 3).

Moreover, the front plate 10 that covers the front 30 face of the support plate 12 also has three orifices 24 and an opening 28 respectively corresponding to the three orifices 22 and the opening 26 in the support plate 12.

Furthermore, as shown in figure 1, the front plate 10 has an edge portion 30 that runs along the edge 35 portion 20 of the support plate 12 and carries a rim 32

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... À e bearing against at least one portion of the interengaging rim 18. The rim 32 of the front plate 12 extends parallel to and in the same direction as the interengaging rim 18, which has a portion 34 that extends beyond the edge 5 portion 42 of the rim 32 of the front plate 10...DTD: Figure 3 shows in section a box 36 of the electrical device according to the invention adapted to be mounted on a partition wall 38 so that it projects therefrom. 10 As shown in figure 3, the support plate 12, provided with the device mechanism 14 and covered with the front plate 10, is mounted on the box 36 so that the device mechanism is accommodated inside the box. A rocker switch button 39 forming the actuation portion of the 15 device mechanism projects from the front plate 10.

Figure 3 also shows the interengaging rim 18 of the support plate 12 bearing against the inside faces 40 of the walls of the box 36 to retain the support plate 12 in a fixed position relative to the box 36. In this way, the 20 front plate 10, which is fastened to or integral with the support plate 12, is also held in a fixed position relative to the box 36.

An edge surface 42 of the rim 32 of the front plate TO bears against an edge surface 44 of the edge portion 25 of the box 36 Accordingly, thanks to the interengaging rim 18, which forms a flange, the rim 32 of the front plate 10 fits perfectly against the edge portion of the box 36 and the whole is held in a fixed position by fixing screws. As a result, the outside face of the 30 electrical device has no projecting edges.

The interengaging rim 18 of the support plate 12 shown in figure 2 is advantageously removable.

It has a central portion 46 and a peripheral portion 48. The interengaging rim 18 projects from the 35 peripheral portion 48, perpendicularly to the plane of

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the central portion 46.

The central portion has an outside edge portion 50 and the peripheral portion has an inside edge portion 52, the central and edge portions coinciding so that their 5 edge portions 50, 52 are spaced from and face each other.

They are connected together at four separate points by fragile connecting means 54, a first embodiment of which is described in detail with reference to figure 6.

Figure 6 shows the inside edge portion 52 of the 10 peripheral portion 48, the outside edge portion 50 of the central portion 46, and the fragile connecting means 54 that connect them. The two opposite edge portions 52 and 50 have respective notches 56, 58 opposite each other.

The fragile connecting means 54 include a pill-shaped 15 member 60 two opposite edge portions of which are respectively connected to the inside edge portion 52 and to the outside edge portion 50 by lugs 62.

The pill-shaped member 60 also has a central groove 63 on one of its faces adapted to receive the end of a 20 screwdriver, for example. As a result, by rotating the screwdriver, the lugs 62 are sheared off to release the inside edge portion 52 and the outside edge portion 50 from each other.

Accordingly, by fracturing the four fragile 25 connecting means, as shown in figure 2, the peripheral portion 48 that carries the interengaging rim 18 can be entirely separated from the central portion 46.

Figure 4 shows the peripheral portion 48 entirely detached from the central portion 46, which is fastened 30 to or integral with the device mechanism 14. Figure 4 shows the notches 56 in the outside edge portion 50 of the support plate 12 and the notches 58 in the inside edge portion 52 of the peripheral portion 48.

Thus the support plate 12, inserted between the 35 front plate 10 and the device mechanism 14 and with its

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*e a - À interengaging rim 18 removed, is adapted to be mounted on boxes built into a partition wall without the edge portion 20 of the support plate impeding the rim 32 of the front plate 10 from bearing against the surface of 5 the partition wall.

Figure 5 shows in vertical section the front plate 10 and the support plate 12 from which the interengaging rim 18 has been removed. For the sake of clarity' the interengaging rim is shown in the figure in dashed 10 outline.

Figure 5 makes it clear that the interengaging rim 18 would not allow the front plate 10 to be pressed perfectly against the surface 64 of a partition wall 66, because the device mechanism 14 is adapted to be engaged 15 in a box 68 but the interengaging rim Is, which extends beyond the rim 32 of the front plate 10, would abut against the surface 64 if it were not removed, and would then prevent the rim 32 from coming to bear directly against the surface 64 of the partition wall 66.

20 Thus the support plates 12 are produced in the standard way with a removable interengaging rim 18 and are adapted either to be mounted in a box projecting from a partition wall or in a box built into a partition wall.

The standard support plates 12 can be moulded in 25 one piece from a plastics material, which reduces their production costs and provides a relatively simple way to obtain the fragile connecting means 54. Support plates 12 of this kind can be moulded from polycarbonate, polyamide, PVC, or polyester, for example, achieving a 30 compromise between the required stiffness of the connection between the central portion 46 and the peripheral portion 48 and the relative weakness required so that the connection can be fractured using a simple everyday tool such as a screwdriver.

35 Figure 7 and figure 8 show two other variants of

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C. À- e... e the fragile connecting means.

Figure 7 shows the outside edge portion 50 of the central portion 46 and the inside edge portion 52 of the peripheral portion 48, the two opposite edge portions 50 5 and 52 being connected together by a connecting lug 70 surmounted by two bearing rims 72, 74 respectively attached to the inside edge portion 50 and the outside edge portion 52. A screwdriver can be inserted between the two bearing rims 72, 74 to fracture the connecting 10 lug 70 by forcibly moving the bearing portions 72, 74 in opposite directions.

Figure 8 shows the inside edge portion 50 and the edge portion 52 of the central portion 46 and the peripheral portion 48 and the connecting lug 70. The 15 peripheral portion 48 has a projecting tongue 76 overlying the connecting lug 70 and the inside edge portion 50 of the central portion 46. Accordingly, the connecting lug 70 can be broken by a screwdriver inserted between the tongue 76 and the central portion 46 in the 20 vicinity of the edge portion-50.

The present invention is in no way limited to the embodiments described and shown, variants of which within the scope of the invention will suggest themselves to the person skilled in the art.

Claims

À À À À.. À ce e À e À À - CLAIMS

1. An electrical device including a support plate and a box adapted to receive the support plate, which has a rear face and carries an interengaging rim that 5 projects from the rear face, extends along the edge portion of the support plate, and is adapted to bear against inside faces of walls of the box to fasten the support plate to the box.

2. An electrical device according to claim 1, 10 including a front plate fastened to or integral with the support plate, an edge portion of the front plate ax-tending along the interengaging rim and being adapted to be positioned facing an edge surface of the edge portion of the box.

153. An electrical device according to claim 2, wherein the edge portion of the front plate carries a rim bearing against at least a portion of the interengaging rim of the support plate and an edge surface of the rim of the front plate is adapted to bear against the edge 20 surface of the edge portion of the box when the support plate and the box are fastened together.

9. An electrical device according to claim 2 or claim 3, wherein the box and the front plate are made of metal. 25

5 An electrical device according to any one of claims 1 to 4, wherein the support plate is moulded in one piece from a plastics material.

6. A support plate for an electrical device mechanism, in particular for an electrical device 30 according to any one of claims 1 to 5, the support plate having a rear face and an interengaging rim that is removable from the support plate and projects from the rear face.

7. A support plate according to claim 6, including 35 a central portion and a peripheral portion from which the

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interengaging rim projects.

8. A support plate according to claim 7, wherein the peripheral portion and the central portion are connected together by fragile connecting means adapted to S be fractured to separate the peripheral portion from the central portion to remove the interengaging rim.

9. A support plate according to claim 8, wherein the peripheral portion has an inside edge portion and the central portion has an outside edge portion, the edge 10 portions face each other, and the fragile connecting means comprise a plurality of connecting lugs distributed along the inside edge portion and the outside edge portion, which face each other.

10. An electrical device support plate according 15 to claim 9, wherein the inside edge portion and the outside edge portion each have a respective plurality of notches facing each other and the connecting lugs extend into the notches and have drive means adapted to fracture them. 20

11. An electrical device support plate according to claim 9, wherein the inside edge portion and the outside edge portion have a plurality of connecting lugs connecting the two inside and outside edge portions and there is provided for each lug a tongue that is attached 25 either to the outside edge portion or to the inside edge portion and which extends either towards the inside edge portion or towards the outside edge portion, respectively, and over the connecting lug.

12. An electrical device support plate according 30 to any one of claims 6 to 11, moulded in one piece with the interengaging rim from a plastics material.

13. An electrical device substantially as hereinbefore described with reference to the accompanying drawings. 35

14. An electrical device support plate

À À À c a À À substantially as hereinbefore described with reference to the accompanying drawings.