GB2350492A

GB2350492A - Panel-mounted flush accessory box

Info

Publication number: GB2350492A
Application number: GB9911041A
Authority: GB
Inventors: Barry Boothman
Original assignee: TENBY IND Ltd
Current assignee: TENBY IND Ltd
Priority date: 1999-05-12
Filing date: 1999-05-12
Publication date: 2000-11-29
Also published as: GB9911041D0

Abstract

A panel-mounted flush accessory box 100 comprises a body 101, a flange 110 for engaging one side of the panel (not shown) and a clamping member 118 for engaging the other side of the panel. The clamping member 118 being formed integrally with the body 101 and having an aperture for receiving a screw whereby to urge the clamping member into engagement with the panel. Preferably the boz is rectangular with opposed clamping members. A clamping member my be attached to the body by two zones of weakness and engage slots in the body.

Description

2350492 ELECTRICAL MOUNTING BOX The present invention relates to an

electrical mounting box for securing to a sheet material, and more particularly but not exclusively to such a_. mounting box for a cavity wall or cavity ceiling.

When it is desired to secure an electrical socket or switch to a plasterboard cavity wall, it is well known to cut a suitable opening through the plasterboard, and insert a mounting box into the opening, the mounting box having screw-accepting apertures for the fastening screws of the socket or switch. Known mounting boxes have an outwardly extending peripheral flange for engaging against the front surface of the plasterboard and clamping members which are typically deployed outwardly to engage the rear surface of the plasterboard after the box has been introduced into the opening. To allow for different thicknesses of plasterboard the clamping members are commonly movable.

one known cavity wall mounting box has a side wall extending to define a generally square opening, the box further having a base wall and an outwardly- extending top flange. Cut out portions are provided in opposing regions of the side wall and an outwardlyextending bracket member is inserted through each cut out portion to engage with the rear surface of a plasterboard wall, the bracket member having a metal coil spring for urging the outwardly-extending bracket towards the rear surface of the top flange. The bracket portion has a threaded metal insert for engaging a securing screw of a switch or socket so that after the box is mounted to a plasterboard surface and the switch or socket is applied thereto, tightening of the screw further urges the bracket portion towards the outwardly-extending flange whereby the box is securely clamped on both sides of the plasterboard.

The known mounting box is made of plastics material.

To insert the mounting box into an opening in a plasterboard surface, first the bracket portions must be either removed or 2 retracted inwardly so that they do not extend outwardly of the side wall. The box is then introduced into the opening and the bracket portions are deployed outwardly and then released so that the spring force causes them to engage behind the plasterboard.

The device is acceptable in use but is complex in manufacture. For example, the use of the coil spring is disadvantageous in increasing the component count, and in increasing the complexity of assembling the device during manufacture. The bracket portions are separately manufactured from the rest of the box and, after the springs have been inserted into the bracket portions, must then be further assembled into engagement with the cut outs of the box.

It is accordingly an object of the present invention to at least partially overcome the difficulties of the prior art.

According to a first aspect of the present invention there is provided an electrical mounting box for securing to a sheet material, said sheet material having a front face and a rear f ace, wherein the box has a body def ining a cavity f or an electrical component to be mounted to said sheet material using said box, the body having a flange portion for engagement with said front face, said box further having plural clamping portions for engagement with said rear face, wherein each clamping portion is formed integrally with said body and has an aperture for receiving a screw whereby said clamping portion is urged into said engagement.

Preferably each clamping portion is secured to said body via at least a first weakened zone.

Advantageously said body comprises a peripheral wall defining plural slots for said clamping portions.

Conveniently there are provided two opposing slots.

3 In a first embodiment said peripheral wall portion comprises plural wall regions, each wall region being disposed at right angles to a successive wall region whereby said box is square or rectangular.

In a second embodiment said peripheral wall portion is generally circular.

Preferably said clamping portions have opposing edge channel regions for engaging said wall portion adjacent said slots.

Advantageously said channel regions comprise opposing channel walls spaced apart by an amount less than a thickness of said wall portion of said body to thereby resiliently grip said wall portion.

Advantageously said wall portion and said clamping portions further have inter-engaging surface formations.

Conveniently said surface formations comprise upstanding ribs extending, in use, transverse to said slots.

Preferably each clamping portion is secured to said body via a respective elongate member having a respective weakened zone at each end thereof.

Advantageously said elongate member has a gripping portion disposed at an end thereof closest to said body portion.

Conveniently each slot has an insertion aperture at one end thereof whereby a said clamping portion can be introduced into said slot.

Conveniently a resilient tongue extends into said insertion aperture.

An embodiment of the present invention will now be described, by 4 way of example only with reference to the accompanying drawings in which:- Figure 1 shows a perspective view of a cavity wall box of the prior art;

Figure 2 shows a perspective view of a bracket member of the box in Figure 1; Figure 3 shows a cross-section of the bracket member of Figure 2 taken along the line III-IIII; Figure 4 shows a front perspective view of a mounting box incorporating the present invention; Figure 5 shows a perspective view of a clamping portion in the box of Figure 4; and Figure 6 shows a side elevation of the box of Figure 2, showing the slot.

In the various figures like reference numerals refer to like parts.

Referring first to Figure 1-3, a known cavity wall box 1 has four side wall portions 10, 11, 12, 13 defining a generally square cavity having a base wall 14. An outwardly- extending peripheral flange 15 extends from the top of the side wall portions 10-13. Two bracket members 20, 30 are disposed in respective slots 16 in opposing side wall portions 11, 13. Each bracket member 20 comprises a planar plate 21 extending along the slot, and a perpendicularly-extending portion 22 towards one end of the plate. The plate 21 is generally rectangular, and a further rectangular member 23 of reduced thickness extends from the two sides and top of the plate 21 so that the plate 21 forms a step, as shown in Figure 3.

on the face of the plate opposite the perpendicularly-extending portion 22, there is a cylindrical portion 25 which, at the top thereof houses a threaded metal insert for a securing screw and towards the bottom houses a part of a metal coil spring 26.

The slot 16 in the side walls 11, 13 have a width which corresponds to the width of the plate 21 so that the bracket member 20, 30 can be located in the slots by the region 23 of reduced thickness. The base wall has an engagement finger for the spring 26 so that the perpendicular portion 22 is resiliently biased towards the outwardly-extending flange 15.

The box of Figures 1-3 is acceptable in use, but it will be appreciated that the need to separately manufacture the bracket members and then to assemble the coil springs into those bracket members before further assembly into the cut outs of the box adds substantially to the cost of the box.

Referring now to Figure 4, an electrical mounting box 100 incorporating the invention has a body 101 defining a cavity 102 for an electrical component to be mounted to the box. The body is formed from four peripheral side wall portions 104, 106, 108, 110 and a base wall 112 which together define the cavity 102. At the top of the side wall portions 104-110 there is an outwardly-extending peripheral flange 114 which in use engages with the f ront f ace of sheet material to which the box is mounted. Depending from opposite portions of the flange 114 are two clamping portions 116, 118, secured to the f lange 114 via first weakened zones 120.

Two opposing side wall portions 106, 110 each have a respective slot 122 therethrough, said slot having a constant width. The slot opens out to a wider insertion zone 122 adapted to allow the clamping portions to be inserted therein for engagement into the slots. A resilient tongue 123 extends upwardly into the insertion zone.

6 The box is shown in the 'as manufactured state in use, the clamping portions 116, 118 are removed from the body 101 at the weakened zones 120 and are then urged against the resilient tongue 123 into the insertion zone 123. The tongue 123 resiliently urges the clamping portion upwards so that it becomes engaged into the slots 122. Then it can be moved upwardly, to abut behind the rear face of the sheet material to which the box is to be secured.

Referring now to Figure 5, a clamping portion 116 consists of a clamping body portion 140 connected via a second weakened zone 142 to an elongate web member 144 having at the opposite end thereof, the end at the time of manufacture closest to the body portion, a gripping portion 146. The clamping body portion 140 has opposing edge channel regions 150 which in use engage the side wall portions 106, 110 adjacent the slots 122. The channel regions have opposing channel walls, 152, 154 which are spaced apart by an amount less than the thickness of the side wall portions 106, 110 so that when the clamping portion is disposed in and engaged with the slot 122 the channel walls grip the side wall portions.

The clamping body portion 140 further has an outwardly- extending engaging portion 160 extending perpendicular to the channel walls 152, 154 at the front thereof. Extending perpendicular to those walls in the opposite direction is a cylindrical portion 162 which includes a through hole for a threaded insert. The second weakened zone 142 extends from the rearmost extremity of the cylindrical wall 162.

In use, when the clamping member is disposed in the slot 122, the cylindrical portion 162 is disposed within the cavity 102 and the outwardly-extending engaging portion 160 extends outwardly from the box. The outer channel wall 154 engages with a portion of the outer face of the side wall portions 106, 110.

The face of the first channel wall 154 is formed with a saw-tooth 7 profile and the side wall portions 106, 110, in the region of the slots 122 is provided with a ribbed surface formation so that the saw tooth formation of the first channel wall 154 engages into the ribbed zone and is retained there by the resilience of the channel walls 152, 154.

In use, the body 101 of the box is introduced into an opening in a sheet material until the flange 114 abuts the one face of the sheet material. Then the clamping portions 116 are introduced via the insertion zone 123 into the slot 122 which results in the gripping portions 146 protruding upwardly from the box. The spacing provided by the cylindrical wall 162 is such that the gripping portion 146 is readily accessible, being spaced from the inside of the side wall portions 106, 110. Then the gripping portions 146 can be gripped between finger and thumb and ur ged away from the base wall 112 until the outwardly-extending engaging portion 160 abuts the rear surface of the sheet material to which the box is to be mounted. The ratchet action of the saw tooth formation on the first wall 154 and the upstanding ribs on the side wall portions allow the clamping portions to be tightened against the sheet material but once tension on the gripping portion 146 is released, the clamping portions remain in situ. At this point, the elongate member 144 may be broken away from the clamping portion 140 at the second weakened zone 142, or alternatively if desired the elongate member may be bent backwards and down into the box.

Then a blanking plate, switch or socket can be offered to the cavity 102 after connecting cabling as required - and the securing screws engaged in the inserts of the cylindrical walls 162. As the screws are tightened into the inserts, the clamping body portion 140 is drawn into yet tighter engagement with the rear surface of the sheet material so that the box becomes tightly engaged with the sheeting material.

The box is preferably one-piece moulded using polypropylene and is dispatched with the clamping members secured to the body 8 thereof.

In one embodiment the clamping portion 116 has a pin-like protrusion from the rear of the gripping portion 146 which engages in a corresponding hole in the side wall portion 106, 110 so that for dispatch purposes the clamping portions lay along the side wall portions on the outside thereof. In another embodiment, a first weakened zone is disposed such that the clamping portions 116 are disposed along the inner surface of the side wall portions 110, 106 for dispatch purposes.

In another embodiment, the box is generally circular in section, having a single peripheral wall. This embodiment is especially suitable for mounting ceiling rose fittings.

9

Claims

CLAIMS:

1. ' An electrical mounting box for securing to a sheet material, said sheet material having a front face and a rear face, wherein the box has a body defining a cavity for an electrical component to be mounted to said sheet material using said box, the body having a flange portion for engagement with said front face, said box further having plural clamping portions for engagement with said rear face, wherein each clamping portion is formed integrally with said body and has an aperture for receiving a screw whereby said clamping portion is urged into said engagement.

2. An electrical mounting box-as claimed in claim 1, wherein each clamping portion is secured to said body via at least a first weakened zone.

3. An electrical mounting box as claimed in claim 1 or claim 2, wherein said body comprises a peripheral wall defining plural slots for said clamping portions.

4. An electrical mounting box as claimed in claim 3, wherein there are provided two opposing slots.

5.. An electrical mounting box as in any preceding claim, wherein said peripheral wall portion comprises plural wall regions, each wall region being disposed at right angles to a successive wall region whereby said box is square or rectangular.

6. An electrical mounting box as claimed in any of claims 1-4, wherein said peripheral wall portion is generally circular.

7. An electrical mounting box as in any preceding claim, wherein said clamping portions have opposing edge channel regions for engaging said wall portion adjacent said slots.

8. An electrical mounting box as in claim 7, wherein said channel regions comprise opposing channel walls spaced apart by an amount less than a thickness of said wall portion of said body to thereby resiliently grip said wall portion.

9. An electrical mounting box as in claim 8, wherein said wall portion and said clamping portions further have inter-engaging surface formations.

10. An electrical mounting box as in claim 9, wherein said surface formations comprise upstanding ribs extending, in use, transverse to said slots.

11. An electrical mounting box as in any preceding claim wherein each clamping portion is'secured to said body via a respective elongate member having a respective weakened zone at each end thereof.

12. An electrical mounting box as in claim 11, wherein said elongate member has a gripping portion disposed at an end thereof closest to said body portion.

13. An electrical mounting box as in claim 3 or claim 4, wherein each slot has an insertion aperture at one end thereof wherein a said clamping portion can be introduced into said slot.

14. An electrical mounting box as claimed in claim 13, wherein a resilient tongue extends into said insertion aperture.

15. An electrical mounting box constructed and arranged substantially as herein described with reference to or as shown in Figures 4 and 5 of the accompanying drawings.