GB2464938A

GB2464938A - Electrical accessory box

Info

Publication number: GB2464938A
Application number: GB0819844A
Authority: GB
Inventors: James Parrott; Michael Herbert
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-10-29
Filing date: 2008-10-29
Publication date: 2010-05-05
Also published as: GB0819844D0

Abstract

An electrical mounting box for installation in a dry lined or cavity wall has an open front, a back wall and side walls at top, bottom, left and right sides, and at least one flange extending outwardly from one or more of the side walls. At least one side wall 4 is profiled to permit engagement of the mounting box in a hole in a section of sheet material 14 by rotation D of the mounting box about an axis P substantially parallel to the sheet material. The side wall may be planar at an oblique angle, or may be curved (see Fig 7). The opposing side wall may have a connector 10 for the connection of cable conduit.

Description

Electrical Accessory Box

BACKGROUND

The present invention relates to an electrical accessory box of the type for insertion into a hole in a sheet of material constituting e.g. part of a cavity wall.

This kind of accessory box is commonly called a dry lining box.

A widely used type of electrical accessory box has an open front, a back wall and side walls at top, bottom, left and right sides, and flange extending outwardly from one or more of the side walls. In use, the box can be mounted in a hole in the cavity wall whilst the flanges engage the front face of the sheet. Various adaptations are known to secure the box in position, for example various types of clamp which engage with the back face of the sheet.

Usually, such electrical accessory boxes feature apertures in the side and/or back walls through which electrical cable can pass for connection to further appliances or a power supply. Once in position, a faceplate may be fastened over the open front.

It is often necessary to provide mechanical protection for cables within cavity walls. Conduit is especially useful in this context. Connectors or fittings are used to join conduit to electrical accessory boxes. This is usually done by pushing a threaded connector through a pre-punched hole in the electrical accessory box called a knock-out and securing with a locknut.

A problem with such a system is that when a conduit adaptor is fitted to the electrical accessory box, it projects outwardly from the side of the box and prevents the box from entering into the hole in the sheet material.

Alternatively, if the electrical accessory box is installed in the hole, it is subsequently difficult to attach the connector without access to the back face of the sheet, which is often not practical.

The present invention seeks to overcome these and other limitations of the

prior art.

SUMMARY OF THE INVENTiON

According to a first aspect, the invention provides a mounting box for an electrical wiring accessory, the mounting box being adapted for mounting in a hole in a section of sheet material, the mounting box having an open front, a back wall and side walls at top, bottom, left and right sides, at least one flange extending outwardly from one or more of the side walls, wherein at least one side wall is profiled to permit engagement of the mounting box in a hole in a section of sheet material by rotation of the mounting box about an axis substantially parallel to the sheet material.

DETAILED DESCRIPTiON OF THE INVENTION

The mounting box of the invention allows for installation with an adaptor or other outwardly-projecting feature affixed to one of the side walls of the box already in position. Conventional mounting boxes of the type known in the art do not permit this, as the adaptor obstructs the passage of the box into the hole.

Preferably, there are at least two flanges, each extending from a respective side wall. Preferably, each side wall has an outwardly extending flange. More preferably, the flanges form a continuous flange.

The box may be manufactured of any suitable material, such as metal (e.g. steel) or an engineering plastics material. PVC or UPVC are preferred.

Preferably, the box comprises locking means for securing the box to the sheet material when installed. Various kinds are known in the art, and are described in for example GB2I 17573, incorporated herein by reference in its entirety.

Preferably, the box is adapted to receive a face plate, to cover the open front and form an enclosed space within the back wall and side walls. Preferably, the box comprises internally threaded holes adapted to receive machine screws for fixing the face plate in place.

Preferably, the box comprises holes though which electrical cable may pass.

Preferably, the holes are provided on the side walls and/or back wall.

Preferably, the holes are temporarily sealed with knock outs which may be removed by an operator to expose the holes.

In a preferred embodiment, at least one of the holes is adapted to receive a conduit connector. Several types of conduit connector are known in the art. A preferred conduit connector has a generally cylindrical aspect, with an external thread provided along at least pad of its length. The threaded portion is passed through the hole, and secured with a locknut. The interior of the connector is adapted to receive coduit.

In an alternative preferred embodiment, the mounting box is pre-formed with outwardly-projecting features provided on at least a side wall. Preferably, the outwardly projecting feature is adapted to receive electrical conduit.

At least one side wall is profiled to permit engagement of the mounting box in a hole in a section of sheet material by rotation of the mounting box about an axis substantially parallel to the sheet material. Any profile which accomplishes this object is acceptable.

In a preferred embodiment, the profiled wall is substantially planar, and forms an oblique angle with the back wall. Preferably, the profiled wall forms an angle of at least 90 0 with the back wall, more preferably at least 100 more preferably at least 110, more preferably at least 120 more preferably at least 1300.

In an alternative preferred embodiment, the profiled wall is curved, In an alternative preferred embodiment, the profiled wall features at least a step.

The profiled wall may be any one of the top, bottom, left and right side walls.

Preferably, the profiled wall is the top or bottom wall. More preferably, the profiled wall is the bottom wall.

To install the mounting box, a suitably sized hole is provided in a section of sheet material (e.g. plasterboard). The box is provided with an outwardly-projecting feature on the side wall opposite the profiled wall. The box is inclined relative to the sheet material, and the outwardly-projecting feature passed through the hole. The side wall bearing the outwardly-projecting feature is brought into contact with the corresponding edge of the hole. The mounting box is rotated into the plane of the sheet material, such that the profiled wall passes over the edge of the hole without being obstructed.

An advantage of the present system is that the mounting box may be installed with a conduit connector already mounted, without the need for access to the rear face of the sheet material.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a front view of a mounting box according to one embodiment of the invention.

Figure 2 is a side view of a mounting box according to one embodiment of the invention.

Figure 3 is a perspective view of a mounting box according to one embodiment of the invention.

Figure 4 is a section view of a mounting box with a conduit connector attached.

Figure 5 is a section view of a mounting box during the process of installation.

Figure 6 is a section view of an installed mounting box.

Figure 7 is a side view of a mounting box according to an alternative embodiment of the invention.

Figure 8 is a side view of a mounting box according to an alternative embodiment of the invention.

Figure 9 is a top view of a mounting box according to an alternative embodiment of the invention.

Figure 10 is a front view of a mounting box according to an alternative embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, the mounting box according to one embodiment of the invention is shown in Figures 1, 2 and 3 and is provided with left (1), right (2), top (3) and bottom (4) side walls, and back wall (5). Left (1), right (2) and top (3) side walls project substantially perpendicular from back wall (5). Bottom side wall (4) forms an angle of approximately 135 with back wall (5). Flange (6) surrounds the periphery of left (I), right (2), top (3) and bottom (4) side walls, and projects outwardly therefrom.

Holes (7) are provided in the back wall (5) and left (1), right (2) and top (3) side walls for the passage of electrical wires or conduit connectors and the like therethrough.

Left (1) and right (2) side walls are provided with projections (8) which define internally threaded holes (9) adapted to receive machine screws for attaching a face plate.

Figure 4 shows the mounting box of Figures 1, 2 and 3 in section view, with a conduit connector (10) mounted in a hale (7) in top side wall (3). Connector (10) is externally threaded, and is held in place by locknuts (11) and (12) which clamp the periphery of hole (7).

Figure 5 shows the mounting box of Figure 4, having the conduit connector in place, during the first step of installation in a hole (13) in a section of sheet material (14) having outer (15) and inner (16) faces. Conduit connector (10) is passed through the hole (13) in the sheet material (14), and upper edge of flange (6) comes into contact with outer face (15) of sheet material (14) at a point P. To bring the mounting box into position, it is rotated into the hole about an axis in the region of point P, indicated by arrow D. The profile of bottom side wall (4) enables itto clear the edge of the hole (13).

Figure 6 shows the mounting box of Figure 4 installed in the hole (13). Flange (6) comes into contact with outer face (15) of sheet material. Connector (10) sits behind the inner (16) face, and receives conduit (17).

Figure 7 shows an alternative mounting box according to the invenlion in side view. The bottom side wall (4) is curved.

Figure 8 shows a further alternative mounting box according to the invention in side view. The bottom side wall (4) is stepped.

Figures 9 and 10 show a further alternative mounting box according to the invention in top (Figure 9) and front (Figure 10) views. In this embodiment, left side wall (2) is profiled.

Claims

CLAIMS1. A mounting box for an electrical wiring accessory, the mounting box being adapted for mounting in a hole in a section of sheet material, the mounting box having an open front, a back wall and side walls at top, bottom, left and right sides, at least one flange extending outwardly from one or more of the side walls, wherein at least one side wall is profiled to permit engagement of the mounting box in a hole in a section of sheet material by rotation of the mounting box about an axis substantially parallel to the sheet material.

2. A mounting box as claimed in claim I wherein the side wall opposite the profiled side wall is provided with at least an aperture adapted to receive a connector.

3. A mounting box as claimed in claim 2 wherein the connector is adapted to receive electrical conduit.

4. A mounting box as claimed in claim 1 wherein the side wall opposite the profiled side wall is provided with an outwardly-facing projection.

5. A mounting box as claimed in claim 4 wherein the projection is a connector adapted to receive electrical conduit.

5. A mounting box as claimed in claim 5 wherein the connector is an integral part of the mounting box.

7. A mounting box as claimed in claim 5 wherein the connector is a compression fit connector.

8, A mounting box as claimed in any preceding claim, wherein the profiled side wall is curved.

9. A mounting box as claimed in any one of claims 1 to 7 wherein the profiled side wall is substantially planar, and forms an oblique angle with the back wall, 10. A mounting box substantially as hereinbefore described with reference to any of the figures.