GB2182079A

GB2182079A - Rails for suspended ceiling grids

Info

Publication number: GB2182079A
Application number: GB08526622A
Authority: GB
Inventors: Cecil Dilwyn Daniel
Original assignee: FIRSTEEL METAL PROD
Current assignee: FIRSTEEL METAL PROD
Priority date: 1985-10-29
Filing date: 1985-10-29
Publication date: 1987-05-07
Also published as: GB8526622D0

Abstract

A rail for a suspended ceiling is of inverted T-section with a vertical web 12, a hollow bead 11 along its upper edge and a pair of horizontal flanges 13, 14 at its lower edge. The bottom flanges each have a cranked shoulder 15 forming an inverted channel 16 between the flanges. A "platform strip" (18) of corresponding shape is attached below the two flanges 13, 14 and extends into the channel 16. In an alternative construction (Fig. 2 not shown) the extreme edges of the a flanges are turned upwards (32, 33) to form further upright channels, one on each side of the inverted central channel (16). <IMAGE>

Description

SPECIFICATION Trails for suspended ceiling grids This invention relates to the horizontal rails used in the construction of grids for suspended ceilings. Such rails conventionaily are of inverted T section, the projecting flanges at the bottom of the rail being designed to support the edges of ceiling tiles. It is normal practice to provide a substantially flat undersurface to the rail, which is normally constructed from two shaped strips of metal, the main component being folded about the upper edge to form a double thickness vertical web with two laterally projecting flanges, while the second component is fitted horizontally below the two flanges and its edges are bent upwards to grip these flanges and form a rigid united bar.Rails of this design are satisfactory but have certain limitations, and it is the object of the invention to provide an improved rail which will overcome some of the existing problems.

Broadly stated the invention consists in a suspension rail for a suspended ceiling grid, having a vertical web, a hollow bead or channel at the upper edge and a flange construction at the lower edge of the web, the lower flange construction including a pair of laterally projecting flanges with an intermediate downwardly opening recess or channel between the two flanges. According to a preferred feature of the invention the rail includes a separately formed metal strip attached to the bottom edge of the rail having matching lateral projections and an intervening channel, with the extremities of the projections turned upwards over the flanges of the rail and tightly crimped.

In a particularly preferred construction the web with the hollow bead at its upper edge and the pair of projecting flanges at its lower edge are formed from one unitary metal strip bent and folded about the upper edge, the web being of double thickness, and the two free edges of the stip forming the two lower projecting flanges.

One of the advantages of the invention is that the channel provides means to receive and/or locate one or more additional components such as electric cables or light fittings.

The channel also facilitates a distinctive appearance of the rail from below. For example the internal surfaces of the channel and/or the exposed undersurfaces of the lateral projecting flanges maybe of different tone or colour or surface treatment.

In some embodiments the channel extends upwardly above the level of the lower horizontal flanges which support ceiling tiles or the equivalent between the rails. This enables the tiles to be located more easily with their edges reasonably tight against the rails.

The invention may be performed in various ways and two specific embodiments will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a sectional end elevation through a suspension rail according to the invention, showing adjacent parts of a pair of ceiling tiles and Figure 2 is a similar end elevation showing an alternative construction.

In the example of Fig. 1 the rail is formed from two component metal strips. One strip provides the main body of the rail and is folded about its upper edge 10 to form a hollow bulbous tube or bead 11 with sioping walls, a vertical web 12 of double thickness, a pair of laterally projecting flanges 13, 14 at the lower edge, each of these flanges being provided by the free edge of one of the thicknesses of metal at the web. Each of these lower projecting flanges is also cranked outwardly as shown at 15 to form an inverted channel 16 with a downward opening between the two side flanges.

The second component of the rail is a "platform" strip 18 which has two horizontal parts 19, 20 lying immediately below the flanges 13, 14 and an intermediate channel part 21 which exactly fits into the channel 16.

The extreme edges of these horizontal parts 19, 20 are folded upwards and crimped over the flanges 13, 14 as shown at 22.

This provides a unitary rail construction in which the channel between the two lower flanges opens downwards and the channel may be coloured to distinguish from the adjacent surfaces 19, 20 to provide a distinctive appearance from below or alternatively the channel may be used to accommodate electric cables or other components anchored by simple barbed clips and possibly enclosed by a cover strip fitted in the mouth of the channel.

It will also be noted that the two side flanges of the channel provide abutment surfaces for adjacent ceiling tiles 25, 26 supported on the lower flanges. It is often not convenient that the tiles should be dimensioned to fit close against the vertical webs 12, and this arrangement provides for location of the edges of the tiles when they are not dimensioned to contact the webs 12.

In the modification illustrated in Fig. 2 the construction is in some respects similar and like parts are indicated by the same reference numerals. In this case the two lower flanges 13, 14 each have a free upwardly bent vertical projection 30, 31, the upper edge of which is level with the cranked parts 15. The ceiling tiles 25, 26 in this example are raised on these upper edges of the vertical extensions 30, 31, and if required they may also be arranged to gain support from the crank 15. The vertical extensions provide a certain degree of extra rigidity, and also accommodate a certain range of dimensions of the tiles.

In this example the lower component of the rail with the horizontal portions 19, 20 is provided with similar vertical projections 32, 33 to conform with the parts 30, 31, and is crimped over the upper edges as is shown at 34.

Claims

1. A suspension rail for a suspended ceiling grid, having a vertical web, a hollow bead or channel at the upper edge and a flange construction at the lower edge of the web, the lower flange construction including a pair of laterally projecting flanges with an intermediate downwardly opening recess or channel between the two flanges.

2. A rail according to claim 1, including a separately formed metal strip attached to the bottom edge of the rail having matching lateral projections and an intervening channel, with the extremities of the projections turned upwards over the flanges of the rail and tightly crimped.

3. A rail according to claim 1 or claim 2, in which the web with the hollow bead at its upper edge and the pair of projecting flanges at its lower edge are formed from one unitary metal strip bent and folded about the upper edge, the web being of double thickness, and the two free edges of the strip forming the two lower projecting flanges.

4. A rail according to any of the preceding claims in which the internal surfaces of the channel and/or the exposed undersurfaces of the lateral projecting flanges are of different tone or colour or surface treatment.

5. A rail according to any of the preceding claims in which the channel is formed to receive and/or locate one or more additional components such as electric cables or light fittings.

6. A suspension rail for a ceiling grid substantially in any form as described with reference to the accompanying drawings.