GB2122666A - Suspended ceiling - Google Patents

Abstract

In a ceiling formed of intersecting ceiling members 1, 2, 3, 4 (e.g. of generally U-shaped cross-section with the bases of the U's at the bottom) an opening e.g. for lighting, is stabilised by a rigid frame formed by four frame members 6. The frame will surround the opening, and is supported by brackets 12 which interlock with the respective frame members 5. Each bracket 12 has a locating part 18 which is inserted into the top of the U of the ceiling member 1, 2, 3 or 4. It is not necessary to fix the part 12 to the ceiling member 1, 2, 3 or 4 and some horizontal play can be allowed. However, the weight of the frame is taken by the brackets 18 and the frame stabilises the opening. In order to facilitate assembly, the brackets 18 can be slid along the frame members 6 into their correct position. A detachable panel 22 is held in the opening by means of horizontally- sliding, spring-loaded bolts 23 actuated by projecting handles 25. <IMAGE>

Description

SPECIFICATION Suspended ceiling Background of the Invention There are known suspended ceilings which comprise a grid of intersecting ceiling members GB 1 472 285 describes one such ceiling.

Openings can be formed in the grid for various purposes, such as for access or for light fittings; the openings would be substantially larger than the normal open cells or spaces between the intersecting ceiling members and would normally be closed by suitable access panels. As the openings interfere with the continuity of the grid structure, it is desirable to strengthen or stabilise the ceiling members forming the outsides of the openings, without distorting the remainder of the ceiling, so that the openings are held true when the access panels are removed.

The invention provides suspended ceilings as claimed in Claim 1 or 1 6 and methods as claimed in Claim 17 or 18. The remaining Claims claim preferred features of the invention.

Using the invention, the frame members form a frame surrounding the opening, and at least the frame members associated with the carrying members are located with respect to the ceiling members at the sides of the opening by way of the downwardly-projecting locating parts, at least in one direction at right angles to the respective side of the opening. In this way, the frame can take up and transfer across the opening the horizontal tensions which are within the grid, and thus stiffens the area immediately around the opening.

Some play can be left so that there is less risk of interfering with and distorting the ceiling; however, the support members can if desired support the ceiling members which form the sides of the opening and prevent sagging. In any case, the weight of the frame is supported and is not transferred to the ceiling grid. The opening can be closed by a drop-down access panel formed by a grid of the ceiling members, and the panel can be held in position in a simple manner, for instance using horizontally-sliding bolts which pass through holes in the ceiling members at the sides of the opening into detents in said downwardlyprojecting locating parts. The access panels is preferably not hinged, being completely removable when the bolts are retracted.

Using such an access panel, the invention is particularly useful when there is a light fitting immediately above the grid, with very little space between the bottom of the light fitting and the grid. In a preferred arrangement, the light fitting can rest on the frame, with a suitable gasket in between if desired.

A further advantage of the invention is that the frame can give a sharp profile to the edges of the opening, without being particularly dominant, and without disturbing the visual continuity of the grid when the access panel is in position.

The support members are preferably on just two opposite sides of the frame.

The support members could just be tension members or hangers attached directly to the frame members. However it is preferred to use longitudinally slidable profiled support members cooperating with the frame members, which would be profiled in a complementary manner.

In theory at least, only two frame members on opposite sides of the opening need be profiled to cooperate with the carrying members.

For assembly of the arrangement with slidable support members, the frame members and support members can be pre-assembled with the remainder of the grid, before the grid is mounted in position. However, in a preferred alternative, the grid can be mounted in position, and the frame members and support members positioned later; the frame is formed with the support members in position on the outside of the frame, and is inserted up through the opening and subsequently dropped into position. In either case, the support members can be slid along the frame members so that they are in their correct positions, either before or after connecting the support members to further support members such as suspension rods which will support the first support members and hence the frame members.

Though it is desirable that the frame members and support members have cooperating abutments which prevent the support members sliding off the frame members in the direction transverse to the frame members and away from the opening, this is not essential. It would be possible to support the support members with e.g.

suspension rods, insert the frame up through the opening, swing out the support members so as to drop the frame into position, and then swing the support members back so that they support the frame members.

The invention was specifically designed for a suspended ceiling of the type disclosed in GB 1 472 285, where the intersecting ceiling members are of generally U-shaped cross-section with the bases of the U's at the bottom, though the tops of the U's may be closed by an inwardlyprojecting flange on one side of the U. In this case, said downwardly-projecting part can be inserted into the tops of the U's (if necessary, with the removal of the flange referred to), thus providing good location and preventing substantial movement of the respective ceiling member horizontally both towards and away from the opening, at least after a predetermined play of say 1 mm.

However, the invention could be used with ceiling members in the form of flat strips, for instance by having the downwardly-projecting part of forked construction, forming a downwardly-facing channel into which the ceiling member is inserted.

Said downwardly-projecting locating parts are preferably on the support members (whether sliding or not). This can avoid having to slot the locating parts as the support members can be sufficiently short to fit between the projecting hooks or nibs at the ends of ceiling members running at right angles to the respective side of the opening.

Preferred Embodiment The invention will be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is an exploded isometric view of a suspended ceiling in accordance with the invention; and Figure 2 is a section, on a larger scale, along the plane Il-Il shown in Figure 1.

The suspended ceiling is of the type disclosed in GB 1 472 285, being in the form of a grid of intersecting ceiling members of generally U-shaped cross-section with the bases of the U's at the bottom. The ceiling members are often called "blades" in the art, and are in the form of long hanger runners 1, cross-runners 2, top-notched intermediate members 3 and bottom-notched intermediate members 4. The grid defines an opening, shown in Figure 1 ,for instance for a light fitting 5, indicated in Figure 2.

The opening is stabilised by a frame formed by four profiled, extruded aluminium frame members 6 which are rigidly held together at the corners in any suitable way, for instance by cleats 7 and grub screws (not shown), the frame members being e.g.

close butted, mitred or square cut. As can be seen in Figure 2, each frame member 6 has two parts forming a generally L-shaped cross-section, the horizontal limb 8 projecting inwards towards the opening and being lipped. An e.g. 9 mm wide standard adhesive strip gasket 9 is positioned on top of the limb 8, behind the lip. The gasket 9 cushions the edge of the light fitting 5 and also prevents leakage of light. The vertical limb of the frame member 6 has an upper, horizontallyprojecting flange 10 with a downwards lip on it and a lower, horizontally-projecting flange 11 with an upwards lip on it, forming a track.

On at least two opposite sides of the frame, two short, profiled, extruded aluminium support members or brackets 1 2 fit in the track of each frame member 6. Each bracket 12 is shorter than the side length of the normal open cell or space between two adjacent ceiling members 4. Each bracket 12 has an upper flange 13 with an upwards lip on it and a lower flange 14 with a downwards lip on it, the respective lips interengaging to form abutments preventing the bracket 12 sliding off the frame member 6 in the horizontal direction away from the opening.At the same time, the upper flanges 10, 13 and/or the lips of the lips thereon form support and slide surfaces supporting the frame member 6 while enabling the brackets 1 2 to slide along the frame member 6; the lower flanges 11, 14 and/or the lips thereon prevent the brackets 12 dropping down off the frame member 6. Each bracket 1 2 has a large flange 1 5 which projects away from the opening. Further support members, shown as suspension rods 16, are attached to the flanges 1 5 and are in turn taken up to small beams 1 7 in the roof void.Each bracket 1 2 also has a downwardly-projecting locating part 1 8 which engages in the top of the ceiling member (Figure 1 shows a hanger rail 1 in this position) and locates the ceiling member. It will be seen that there are gaps (the total clearance can be about 1 mm), allowing some sideways play of the grid with respect to the frame and preventing gross distortion. There is an outwardly-projecting offset 1 9 at the top of the part 18, resting on the top of the ceiling member. In addition, the part 1 8 has a narrow channel defined between two small flanges 20, 21, for the purposes explained below.

The opening is closed by an access panel 22 formed by a grid of intersecting ceiling members 3, 4 with raw ends. If it is large, the access panel 22 can be reinforced by a frame concealed within the ceiling members 3, 4. The access panel 22 is held in place by horizontally-sliding bolts 23 within the respective ceiling members 3; the ends of the bolts 23 pass through holes in the walls of the ceiling members 1 and into detents formed by the narrow channels referred to above (see Figure 2). The bolts 23 are spring-loaded outwards, and are guided by reinforcing plates 24 which are inserted and suitably fixed in the outer ends of the ceiling members 3. The inner ends of the bolts 23 have upwardly-projecting handles 25. Using both hands, an operative can reach up through the grid and use his fingers to squeeze the handles 25 towards each other to release the panel 22.

Assembly The suspended ceiling is mounted in position, leaving the opening unobstructed.

The frame is made up of the frame member 6, and the brackets 12 are slid on to the sides.

By angling and tilting, the frame is inserted up through the opening and is correctly positioned above the opening. The brackets 12 are slid along to their correct positions, and the frame is then lowered so that the parts 18 of the brackets 12 are within the ceiling members. As can be seen from Figure 1 , the brackets 1 2 which are opposite each other are staggered, being on opposite sides of the beam 17; the reason for this 1rrangement is the staggering of the hooks or nibs on the ends of the ceiling members 3. The brackets 12 are pushed tight against the respective face of the hook or nib on the end of the ceiling member 3. In this way, the bolts 23, which lie within the ceiling members 3, can engage the ends of the narrow channels in the brackets 12.

The suspension rods 1 6 are dropped down through the fixings in the beam 1 7 and are bolted on to the brackets 12. Level and alignment is checked.

The light fitting 5 can then be lowered into place. If desired, its weight can be taken by the frame.

General The pitching of the ceiling members 1, 2, 3, 4 can be of any suitable dimension, and the opening can be of any suitable size, though standard side lengths are 300 mm, 600 mm, 1200 mm or 1800 mm. If the side length is 1200 mm or less, just two brackets 1 2 can be used, and it is preferred not to secure the ceiling members 1 at the sides of the opening to the brackets 12.

However, if the side is longer than 1200 mm, a third, central bracket 1 2 (or more brackets) can be inserted, the side ceiling members 1 being screwed to the central brackets 1 2 so that the brackets actually support the side ceiling members 1; self-tapping screws (not shown) can be screwed through the wall of the ceiling members 1 and into the narrow channels. In addition, strengthening members can be inserted within the channels of the ceiling members 3, 4 of the access panel 22 to stabilise the panel 22, for all panel sizes.

Although the frame members 6 and brackets 12 have been claimed as part of the ceiling system, they can be sold separately or as a kit-ofparts and are themselves inventive.

Claims (18)

1. A suspended ceiling comprising: a grid of intersecting ceiling members, the grid defining an opening which is substantially larger than the normal spaces between the intersecting members; frame members forming a frame surrounding the opening; support members supporting at least some of the frame members; and downwardly-projecting locating parts locating with respect to the frame a ceiling member which extends along the respective side of the opening.

2. The ceiling of Claim 1, wherein at least some of the frame members have a support and slide surface projecting out on the opposite side of the frame member to the opening, and each member has a support and slide surface supporting the respective frame member by way of its support and slide surface, which support and slide surfaces could, at least during mounting, slide relative to each other in the longitudinal direction of the respective frame member, for adjustment of the position of the support member relative to the frame member.

3. The ceiling of Claim 2, wherein the support members and the respective frame members have cooperating abutments which prevent the support member sliding off the respective frame member in a horizontal direction away from the opening.

4. The ceiling of Claim 2 or 3, wherein the support members and the respective frame members have further support and slide surfaces which prevent the support members dropping down off the respective frame members.

5. The ceiling of Claim 2, wherein each support member or respective frame member has an upper, horizontally-projecting flange with an upwards lip on it and a lower, horizontallyprojecting flange with a downwards lip on it, and each respective frame member or support member has an upper, horizontally-projecting flange with a downwards lip on it and a lower, horizontally-projecting flange with an upwards lip on it, the flanges of the support member or frame member passing between the lips of the frame member or support member and the respective lips interengaging to form abutments which prevent the support member sliding off the respective frame member in the horizontal direction away from the opening, while the upper flanges and/or the lips thereon form the support and slide surfaces and the lower flanges and/or the lips thereon form further support and slide surfaces which prevent the support member dropping down off the respective frame member.

6. The ceiling of any one of Claims 2 to 5, wherein the support members have flanges which project away from the opening and to which supports are attached, thereby supporting the support members and the respective frame members.

7. The ceiling of any one of Claims 2 to 6, wherein said downwardly-projecting locating part is on the support member, there being an outwardly-projecting offset at its top, resting on the top of the respective ceiling member.

8. The ceiling of any one of the preceding Claims, wherein said downwardly-projecting locating part has a narrow channel which faces horizontally, for receiving a screw screwed through the respective ceiling member, for securing the locating member to the ceiling member.

9. The ceiling of any one of the preceding Claims, wherein said opening is closed by a panel formed by a grid of intersecting ceiling members and held in place by horizontally-sliding bolts passing into detents in said downwardlyprojecting locating parts.

10. The ceiling of Claim 9, wherein the detents are formed by narrow channels on said downwardly-projecting locating parts, which channels face horizontally towards the opening.

11. The ceiling of Claim 9 or 10, wherein the ceiling members are of generally U-shaped crosssection with the bases of the U's at the bottom, said bolts being within respective ceiling members of said panel.

12. The ceiling of any one of the preceding Claims, wherein said downwardly-projecting locating parts prevent substantial horizontal movement, at least after a predetermined play, of the respective ceiling members both towards and way from the opening.

13. The ceiling of Claim 12, wherein the ceiling members are of generally U-shaped cross-section with the bases of the U's at the bottom, the downwardly-projecting locating parts being inserted into the tops of the U's.

14. The ceiling of any one of the preceding Claims, wherein the frame members have two parts forming a generally L-shaped cross-section, namely a vertical limb and a horizontal limb, the horizontal limb projecting inwards towards the opening.

1 5. The ceiling of Claim 14, wherein the lower limb of the L-shaped cross-section is lipped, a gasket being placed on top of the lower limb, between the lip and the vertical limb.

16. A suspended ceiling comprising a grid of intersecting ceiling members, the grid defining an opening which is substantially larger than the normal spaces between the intersecting members, the ceiling being substantially as herein described with reference to, and as shown in, the accompanying drawings.

17. A method of stabilising the opening in the ceiling of any one of Claims 1 to 15, comprising forming the frame by fixing the frame members together, and using the downwardly-projecting locating parts to locate the frame with respect to the ceiling members which form the sides of the opening.

18. A method of stabilising an opening in a ceiling, substantially as herein described with reference to the accompanying drawings.