GB2305304A

GB2305304A - Installing switch boxes

Info

Publication number: GB2305304A
Application number: GB9518063A
Authority: GB
Inventors: Owen Charles Swinn
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-09-05
Filing date: 1995-09-05
Publication date: 1997-04-02
Anticipated expiration: 2015-09-05
Also published as: GB2305304B; GB9518063D0

Abstract

Electrical fittings are installed on a plastered wall by securing a switch box 10 to an unplastered wall 26, mounting electrical cables 30 on the unplastered wall and routing them into the switch box, placing a cover 18 over the face of the switch box to enclose the switch box, plastering the wall to a thickness substantially equal to the depth of the switch box, separating the cover 18 from the face of the switch box, wiring the electrical fitting to the cables exposed in the switch box, and securing the fitting to the switch box. The cover 18 can be a simple vacuum moulded cover which will be destroyed when the cover is separated from the switch box, with some parts 20 of the cover possibly being left buried in the plaster and the main area 24 of the cover being discarded.

Description

INSTALLING SWITCH BOXES This invention relates to the installation of switch boxes through which electrical cables are connected to switches and/or sockets in building walls.

The boxes with which this specification is concerned are used in association with electrical switches, electrical sockets (whether switched or unswitched), aerial sockets and other units which are to be wired up at a building wall. For the sake of simplicity in this specification, the term "switch box" will be used throughout but this is not to be seen as limiting, and includes boxes associated, inter alia, with any of the functions set out above.

In the installation of switch boxes, a box is fastened to a wall, cables are led into that box and secured to the wall, and then the wall is plastered, with the plaster ending up with a thickness equal to about the depth of the switch box. It often happens that some plaster enters the switch box during the plastering process and has to be cleaned out before the electrician can complete his "second fixing" when the switch, socket or other component is mounted to the switch box.

According to the present invention, there is provided a method of installing electrical fittings on a plastered wall, the method comprising the steps of securing a switch box to an unplastered wall, mounting electrical cables on the unplastered wall and routing them into the switch box, placing a cover over the face of the switch box to enclose the switch box, plastering the wall to a thickness substantially equal to the depth of the switch box, cutting away the cover from the face of the switch box, wiring the electrical fitting to the cables exposed in the switch box, and securing the fitting to the switch box.

By covering the face of the switch box whilst plastering takes place, the danger of plaster entering the box is substantially reduced. The electrician can cut out the front face of the cover to reopen the switch box and to give him access to the electrical cables and to the fastening hardware within the box.

The cover is preferably separated from the face of the switch box by cutting away the part of the cover which bridges the opening for the switch box from the part of the cover which clips onto the edges of the switch box.

The cutting may be performed by running around the edge of the cover with a sharp knife.

In an alternative form, the cover may be perforated to allow it to be easily separated from the edge region.

The invention also provides a cover for a switch box, the cover being adapted to be fitted across the open face of a switch box and having a rim to be fitted to the edges of the switch box and a web spanning the open face, the web being capable of being separated from the rim to allow access to the switch box interior.

The cover is preferably a moulded plastic item which can be clipped to the upstanding walls of a switch box, to retain a web in place across the open face of the box.

The clipping of the rim to the box may require that part of the rim engages over the outer surface of the box walls. The cover may be held to the box by friction, or by a snap-engagement.

In order to facilitate the separation of the web from the rim, the edges of the web may include a groove for the purpose of guiding a knife edge around the junction between the web and the rim.

It may be possible for the cover to be formed with a perforation between the rim and the web, so that the web can just be torn away along the lines of the perforations.

The cover may be a vacuum moulded item.

The invention also extends to a switch box with a cover as set forth above mounted on the switch box.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a conventional switch box; Figure 2 is a perspective view of a switch box cover in accordance with the invention, for use with the switch box of Figure 1; and Figures 3, 4, 5, 6 and 7 show five sequential stages in the installation of an electrical fitting using the method of the invention.

Figure 1 shows a conventional switch box 10 for a single switch. Such switch boxes are standard items of commerce.

They are normally made from sheet metal, and as standard have an opening at their front face which measures 70 mm by 70 mm. Double size switch boxes are also in common use. These boxes have an open face with dimensions 70 mm by 130 mm. (These dimensions are approximate).

The box 10 typically has one hole 12 through which electrical cables can enter the box, two holes 14 by which the box can be secured to a wall, and two opposite side lugs 16 which have threaded bores into which screws can be inserted to secure a switch body to the box.

Such switch boxes are made in varying depths, depending on their application, but the open face area is standard (within the limits of imposed tolerances). Although such boxes are commonly made of metal, the scope of the invention is not restricted to metal boxes.

Figure 2 shows a press-on cover 18 which has a rim 20 for engaging around upper edges of the walls 22 of the box 10, and a web 24 which spans the space within the rim 20.

Further details of the construction will become apparent from the following description of the stages of installation.

Figure 3 shows the box 10 secured to a wall 26 by screws 28. A cable 30 is secured to the wall 26 by a cable tie 32, and the free end of the cable passes through the aperture 12 into the box 10. It is conventional at this stage to strip some of the insulation from the ends of the cable 30 and although only a short length of cable is shown in Figure 3 within the box, in practice a considerable length of cable may be brought through the aperture 12 into the box and may be coiled around on itself.

These operations are carried out by the electrician.

Next, in accordance with the invention, the electrician completes his stage of the work by clipping a cover 18 onto the face of the box 10, as shown in Figure 4. The interior of the box where the bared ends of the cable 30 are located, and where the screw lugs 16 are to be found is then enclosed.

The electrician then leaves the site, and the plasterer applies plaster to the wall 26 to provide a smooth finish to the wall and also to embed the cable 30 so that it is hidden from view. The depth of the switch box 10 will be chosen to be generally equal to the intended depth of plaster covering on the wall, and when the plasterer has finished, the wall has a smooth coating of plaster 34, to a depth on the wall which is equal to the height of the box 10 and the plaster is therefore flush with the top of the box.

The plasterers work is then finished. When the plaster has dried the electrician returns to complete the wiring (the so called "second fixing") and the electrician then has to obtain access to the interior of the switch box 10.

He does this using a knife 36 which he places in a groove 38 around the rim 20 of the cover, to cut away the web 24 from the rim 20. It will be noted that the rim 20 should not be disturbed, because if it is disturbed then the plaster 34 will be disturbed.

The web 24 once cut away from the rim is discarded to leave the box in the situation shown in Figure 6, where the electrician has free and unimpeded access to the interior of the box which will be uncontaminated by any plaster splashes. The electrician then connects the relevant electrical fitting, which may be a switch 40 to the switch box using screws (not shown) which engage in the threaded bores of the lugs 16. The installation of the fitting 40 is then complete.

The construction of the cover 24 may be sufficiently elastic and sufficiently flexible to fit snugly onto boxes from different manufacturers which may have slightly different dimensions within the tolerances allowed.

In order to prevent plaster leaking into the switch box through apertures in the side of the switch box (for example where the lugs 16 are pressed out) the cover may have external walls on the rim which are deeper than those shown and which cover the apertures.

The cover can be made very cheaply from thin gauge material and the engagement between the cover and the switch box does not have to be to a precision level. All that is necessary is that the cover should be capable of being easily fitted onto the switch box and that it should remain in place even if it is accidentally knocked.

Vacuum forming may be a suitable manufacturing method.

The material of the cover should not disintegrate under wet conditions, because there is a lot of water present whilst plastering is being carried out.

To avoid having to use a knife to separate the web 24 from the rim 20, the groove 38 may be replaced by a ring of perforations around the web. It may then be possible for the web to be simply torn away.

The invention provides a cheap and simple way of hindering plaster from entering open switch boxes and therefore saves the electrician considerable time on the second fixing, because there is no need to spend time cleaning out the switch box.

Claims

1. A method of installing electrical fittings on a plastered wall, the method comprising the steps of securing a switch box to an unplastered wall, mounting electrical cables on the unplastered wall and routing them into the switch box, placing a cover over the face of the switch box to enclose the switch box, plastering the wall to a thickness substantially equal to the depth of the switch box, separating the cover from the face of the switch box, wiring the electrical fitting to the cables exposed in the switch box, and securing the fitting to the switch box.

2. A method as claimed in Claim 1, wherein the cover is separated from the face of the switch box by cutting away the part of the cover which bridges the opening for the switch box from the part of the cover which clips onto the edges of the switch box.

3. A method as claimed in Claim 2, wherein the cutting is performed by running a sharp knife around the edge of the cover inside the box.

4. A cover for a switch box, the cover being adapted to be fitted across the open face of a switch box and having a rim to be fitted to the edges of the switch box and a web spanning the open face, the web being capable of being separated from the rim to allow access to the switch box interior.

5. A cover as claimed in Claim 4 which is a moulded plastic item adapted to be clipped to the upstanding walls of a switch box, to retain a web in place across the open face of the box.

6. A cover as claimed in Claim 5, wherein the clipping of the rim to the box requires that part of the rim engages over the outer surface of the box walls.

7. A cover as claimed in any one of Claims 4 to 6, wherein the cover is adapted to be held to a switch box by friction.

8. A cover as claimed in any one of Claims 4 to 6, wherein the cover is adapted to be held to a switch box by a snap-engagement.

9. A cover as claimed in any one of Claims 4 to 8, wherein the edges of the web include a groove for the purpose of guiding a knife edge around the junction between the web and the rim, to facilitate the separation of the web from the rim.

10. A cover as claimed in any one of Claims 4 to 9, wherein the cover is formed with a perforation between the rim and the web.

11. A cover as claimed in any one of Claims 4 to 10 and which is a vacuum moulded item.

12. A switch box with a cover as claimed in any one of Claims 4 to 11.

13. A method of installing electrical fittings on a plastered wall, substantially as herein described with reference to the accompanying drawings.

14. A cover for a switch box, substantially as herein described with reference to the accompanying drawings.