GB2210921A

GB2210921A - Electrical accessory box cover plates

Info

Publication number: GB2210921A
Application number: GB8823635A
Authority: GB
Inventors: Martin Graham Merritt
Original assignee: MORGAN GARY CHARLES
Current assignee: MORGAN GARY CHARLES
Priority date: 1987-10-14
Filing date: 1988-10-07
Publication date: 1989-06-21
Anticipated expiration: 2008-10-07
Also published as: GB8823635D0; GB8724125D0; GB2210921B

Abstract

A cover plate (5) for covering an electrical accessory box (1), particularly during plastering, comprises a pair of hook-shaped projections (7) extending from the rear face (8) of the plate, the projections being engageable as a snap fit over the respective screw fixing lugs (4) of the box. One or more hemispherical projections (10) may be formed on the front face (11) of the plate (5) to provide a visual indication of the position of the plate subsequent to plastering. <IMAGE>

Description

Title: Electrical Accessory Box Cover Plates Field of the invention This invention relates to removeable cover plates for boxes, such as electrical accessory boxes used to house switches, sockets, and dimmer controls.

Background to the invention The installation of electrical wiring systems in buildings requires the use of such electrical accessory boxes which are normally recessed into the walls, the wall then being plastered se that the forward edges of the boxes lie flush with the surface of the plaster. However it is not at all unusual for the boxes to be inadvertently filled with plaster during plastering, requiring them to be cleaned out before a switch or socket panel can be fitted.

It is an object therefore of this invention to provide a cover plate for an electrical accessory box which protects the box from the ingress of plaster during plastering operations, and which can subsequently be removed to facilitate fixing of an electrical accessory in the box.

Summary of the invention According the to present invention there is provided a cover plate adapted to cover an electrical accessory box having lugs for the reception of fasteners to fix an electrical accessory to the box, said plate including holding means to engage a said lug to hold the plate flush against said box.

Preferably the plate has a projection on the outwardly facing surface thereof to visually indicate the position of the plate on a wall after the wall is plastered.

The invention also extends to the combination of such a cover plate and an electrical accessory box having lugs.

Brief description of the drawings A preferred embodiment of the invention will now be described with reference to the accompanying drawing in which: Figure 1 is a plan view of an electrical accessory box for a single 13 Amp outlet socket, switch or dimmer control; Figure 2 is a section through the box shown in Figure i; Figure 3 is rear view of a cover plate for the electrical accessory box shown in Figure 1; Figure 4 is a section along lines Y-Y of Figure 3; and Figure 5 is a section along lines X-X of Figure 3.

Description of embodiment Referring firstly to Figures 1 and 2, a rectangular electrical accessory box 1 made, for example, of cast or sheet metal or insulating material, comprises a base 2 for fixing to a recess in the wall of a building and sides 3 each having projecting inwardly thereof a lug 4 positioned near the outer edge of each side, each lug having a threaded hole to receive a screw for fixing an electrical accessory such as a switch or outlet socket to the box.

Whilst the lugs 4 are shown integral with the sides, it is common practice to provide separate lugs which are retained by small fingers projecting from the side of the box to allow relative sliding movement between said lugs and the sides of the box. This enables the horizontal top and bottom edges of a switch to be aligned with the floor and ceiling line of a building even when the respective box edges are out of alignment therewith.

Referring now to Figures 3 and 5, a rectangular cover plate 5 made of polypropylene comprises engagement or holding means 6 in the form of a pair of hook-shaped projections 7 extending from opposite sides of the rear face 8 of the plate 5 for engaging the respective two lugs 4 on the accessory box 1, land portions 9 extending from opposite sides of the plate 5 being provided to engage respective opposite edges of the sides 3 on the box 1 to prevent the cover plate being bowed inwardly of the box.

A hemispherical projection 10 is provide centrally on the front face 11 of the plate 5, as shown in Figure 5, to provide a visual indication of where the plate, and hence the box, is positioned on a wall in the case where on plastering the face 11 has been covered by the plaster.

As shown in Figure 3, the two projections 7 are located in a position such as to engage respective lugs 4 on the box 1 when the former is snap-fitted to the latter. A flange 12 extends rearwardly from the front face 11 of the plate 5 around the periphery thereof with indented sections 13 running parallel to and spaced from the projections 7 to clear the fingers (not shown) provided on a box where the lugs 4 are retained in sliding relationship with the sides of the box, as previously described.

Furthermore a rectangular aperture 14 is formed in the plate 5 between each projection 7 and the respective indented section 13 to facilitate removing the plate 5 from the box 1 after plastering.

In use, the plate 5 is offered up to the box 1, pressing the projections 7 inwards so that the hooked ends thereof snap over the lugs 4, thereby retaining the cover plate 5 on the box 4, the land portions 9 engaging the edges of the box to prevent the cover bowing inwardly. Should the cover plate 5 be covered with plaster during plastering of the wall to which the box is secured, the hemispherical projection will stand proud of the plaster and give a visual indication of the position of the box on the wall.

Either before or after the plaster sets, the cover plate 5 can be removed by inserting a tool, for example, a screwdriver, in one of the two apertures 14 and against the projection 7, and levering the cover plate away from the box.

The cover plate may be made of other materials than polypropylene, for example PVC or metal. Also instead of providing hook-shaped projections 7, conically-shaped projections can be formed with the plate to engage the threaded holes in the lugs. Furthermore, more than one hemispherical projection may be provided on the front face 11 on the cover plate, or projections of a different shape may be used to provide a visual indication of the position of the plate.

The main advantage of using such cover plates in accordance with this invention, is that it obviates the need to clean out boxes after plastering, thereby saving time. Also the cover plates are reusable and easily cleaned since plaster does not adhere readily to plastics material.

Claims

1. A cover plate adapted to cover an electrical accessory box having lugs for the reception of fasteners to fix an electrical accessory to the box, said plate including holding means to engage a said lug to hold the plate flush against said box.

2. A plate according to claim 1 further comprising a projection on the outwardly facing surface of said plate to visually indicate the position of said plate on a wall after the wall is plastered.

3. A plate according to claim 2 in which said projection is generally hemispherical in shape, and is disposed substantially centrally on said outwardly facing surface.

4. A plate according to any one preceding claim in which said holding means comprises at least one hook-shaped projection engageable as a snap-fitting over said lug on the box.

5. A plate according to claim 4 further comprising an aperture adjacent said projection to enable insertion of a tool therein against said projection to facilitate removal of the plate from the box.

6. A plate according to any one of claims 1 to 3 in which said holding means comprises a conically-shaped projection engageable with a screw threaded hole in said lug.

7. A plate according to any one preceding claim made from a plastics material, such as polypropylene or PVC.

8. The combination of a plate as claimed in any one preceding claim and an electrical accessory box having lugs.

9. A cover plate substantially as herein described with reference to, and as shown in, Figures 3 to 5 of te accompanying drawings.

10. The combination of a cover plate and an electrical accessory box substantially as herein described with reference to, and as shown in, the accompanying drawings.