GB2262948A - A support for a suspended ceiling. - Google Patents

Abstract

A support 20 for a suspended ceiling comprises an upper rolled steel section 21 and a plastics capping 22. The capping is formed by extrusion and comprises inner side walls 24, 25 defining a channel 23 and outer side walls 29, 30, with a cross member 28 extending between the outer side walls and connecting to the inner side walls. The cross member provides rigidity to the capping. <IMAGE>

Description

A SUPPORT FOR A SUSPENDED CEILING The invention relates to a support for a suspended ceiling. The invention also relates to a capping for such a support.

Suspended ceilings generally comprise a support structure in the form of a grid suspended from fixed length hangers into which grid ceiling panels are placed to be supported thereby.

One such support structure is disclosed in our British Patent 2,152,091, the teaching of which are incorporated herein by reference. The structure disclosed in our aforementioned patent comprises plural elongate grid numbers of substantially inverted T-section each having a channel along its length.

The channel is formed to be able to receive the screwthread of a fixing screw or bolt and each member is formed by extrusion.

In the embodiments disclosed in our aforementioned patent the whole member is formed as a single extrusion. The design of the member has been developed and revised since the drafting of our British Patent and the product that we currently sell, whilst maintaining the essential features of the structure defined by the claims of our earlier patent, is quite different in appearance to the original design.

An example of the design of member that we currently manufacture and sell is shown in Figure 1 of the accompanying drawings. The member shown in Figure 1 comprises an upper rolled steel section 1 and a lower extruded aluminium capping 2. The rolled steel section 1 is a standard off-the-shelf component that is both easy and cheap to produce and is readily available from several different suppliers. The lower capping 2 is formed with a channel 3 having side walls 4,5 with a respective threadform formed thereon. A void 6,7 on each side of the channel reduces the amount of material required to form the capping 2 and opposing notches 8,9 in the two sides 10,11 of the capping 2 enable the capping to be fitted to the lower arms 12,13 of the steel section 1.Without the notches 8,9 it would be necessary to use oversize cappings (as compared with the industry standard) and this in turn would require the use of undersize panels. The provision of the notches enables the illustrated capping to be fitted to a standard 14.2 mm steel T-section.

By making the capping 2 from aluminium we are able to provide a support which is strong and functional and is visually pleasing when an installed ceiling system incorporating such supports is viewed from below. Aluminium is a material well suited to extrusion and is both light and strong. Aluminium is however a relatively expensive material and hitherto costs have been minimised by reducing the amount of material in the capping by way of the voids 6,7 for example. Nevertheless, the extruded aluminium capping remains a relatively expensive item to produce.

It would be desirable to be able to use another material, such as a plastics, to form the capping.

However, a plastics extrusion having a solid section, such as the sections shown in our British Patent No.

2152091 is prohibitively expensive to produce.

Furthermore, a plastics extrusion capping having a section similar to that shown in Figure 1 of the accompanying drawings lacks strength and is prone to flexing and/or distortion. In itself this might not be too great a disadvantage, but when a plastics extrusion having a section similar to that shown in Figure 1 is mounted to a rolled steel section as shown in the same drawing the extrusion becomes subject to severe lateral distortion. This distortion is caused by the natural tendency of the lower arms 12,13 of the steel section 1 to spring apart from each other. As a result, the capping becomes unsightly when viewed from below and it becomes difficult, and in extreme cases virtually impossible, to fix a screw in the threadform channel.Furthermore, such a plastics extrusion capping exhibits a tendency to pull away from the steel section when a load of any substance is fixed to the capping. This happens because the notches 8,9 weaken the outer side walls of the capping allowing the walls to flex and the capping to come away from the upper steel section 1.

The present invention aims to overcome at least some of the above problems.

The invention provides a support for a suspended ceiling, the support comprising an upper member substantially formed as an inverted T-section and a plastics capping formed by extrusion which capping comprises opposing inner side walls defining a channel, outer side walls, thereby to strengthen the capping.

The free end portions of each side wall may cooperate with respective portion of the cross member to define receiving channels for receiving a portion of the T-section.

A portion of the cross member may define an outwardly directed channel end face extending between the sides walls of the channel.

The plastics capping may be made from UPVC.

The invention also provides a plastics capping for use in a suspended ceiling, the capping comprising a cross member extending between two outer side walls, a channel defined by two inner walls and a runner receiving portion defined by flanges extending from the side walls and by at least a portion of said cross member.

The side walls may be provided with a threadform to enable the threaded portion of a screw or bolt to be removably secured in the channel.

The invention also extends to a ceiling system incorporating such a support or plastics capping.

The above and further features of the invention are set forth with particularity to the appended claims and together with advantages thereof will become clearer from consideration of the following detailed description of an exemplary embodiment of the invention given with reference to the accompanying drawings.

In the drawings: Figure 1 is a sectional view of a prior art support as described hereinabove; and Figure 2 is a sectional view of a support embodying the invention.

Referring now to Figure 2 of the accompanying drawings, a grid member 20 comprises an upper rolled steel section 21 and a lower extruded plastics capping 22. The rolled steel section 21 is the same as that used in the above discussed prior art member shown in Figure 1 of the accompanying drawings. The extruded plastics capping 22 is formed with a channel 23 having side walls 24,25 each having a threadform formed thereon. A void 26,27 on each side of the channel 23 reduces the amount of material required to form the capping.

Unlike the above discussed prior art capping the extruded plastics capping 22 comprises a cross member 28 which extends between the outer side walls 29,30 of the capping and forms the outwardly directed face 31 of the channel 23. Thus, the cross member 28 serves to provide lateral continuity to the upper portion of the capping 22 and thereby provides the capping with the strength required to resist lateral distortion induced by the natural tendency of the free ends 32,33 of the steel section 21 to spring part.

The capping 22 also comprises inwardly directed flanges 34,35 which co-operate with respective portions of the cross member 28 to define steel section receiving channels 36,37 in which the free ends 32,33 of the steel section are received as shown. Since the receiving channels 36,37 are formed partly by the cross member 28 they are sufficiently resistant to flexing and distortion to avoid the capping coming away from the steel section when a load is fixed to the capping.

It should be noted that in an aluminium extrusion it would be a difficult task to form efficiently a capping including the cross member 28.

This is because the forces involved in plastics extrusion are far less than those involved in aluminium extrusion. Whilst the resistance caused by forming the cross member as shown in Figure 2 would significantly reduce the speed of production of an aluminium extrusion, the effect is negligible in respect of a plastics extrusion.

The capping may be formed from any suitable plastics material and it has been found that UPVC is particularly well suited to this purpose.

The capping 22 may be supplied in any convenient size and it is envisaged that it will be supplied by us in the standard sizes of 15 x 8 mm, 15 x 16 mm and 15 x 26 mm. These sizes are compatible with most ceiling systems including those currently using our aluminium extrusion.

Having thus described the present invention by reference to a preferred embodiment it is to be well understood that the embodiment in question is exempiary only and that modifications and variations such as will occur to those possessed of appropriate knowledge and skills may be made without departure from the spirit and scope of the invention as set forth in the appended claims and equivalents thereof.

Claims (10)

CLAIMS:

1. A plastics capping for use in a suspended ceiling, the capping being formed by extrusion and comprising a cross member extending between two outer side walls, a channel defined by two inner walls, and a runner receiving portion defined by flanges extending from the outer side walls and by at least a portion of said cross member.

2. A capping as claimed in claim 1, wherein said side walls are provided with a threadform to facilitate the securing of the threaded portion of a screw or bolt in the channel.

3. A capping as claimed in claim 1 or 2, wherein a portion of the cross member defines an outwardly directed channel end face extending between the inner walls of the channel.

4. A support for a suspended ceiling, the support comprising an upper member substantially formed as an inverted T-section and a plastics capping formed by extrusion, which capping comprises opposing inner side walls defining a channel, outer side walls having free end portions, and a cross member extending between the free end portions of the two outer side walls and connecting to the inner side walls thereby to strengthen the capping.

5. A support as claimed in claim 4, wherein the free end portions of each side wall co-operate with respective portions of the cross member to define receiving channels for receiving a respective portion of the T-section.

6. A support as claimed in claim 4 or 5, wherein a portion of the cross member defines an outwardly directed channel end face extending between the side walls of the channel.

7. A support as claimed in claim 4 or 5 or 6, wherein the inner side walls are provided with a threadform to enable the threaded portion of a screw or bolt to be removably secured in the channel.

8. A capping or a support as claimed in any preceding claim, wherein the capping is made in UPVC.

9. A ceiling system incorporating a capping or a support as claimed in any preceding claim.

10. A capping or a support substantially as described herein with reference to Figure 2 of the accompanying drawings.