GB2407826A

GB2407826A - Ceiling grids

Info

Publication number: GB2407826A
Application number: GB0323986A
Authority: GB
Inventors: Bob Biddle
Original assignee: BURGESS ARCHITECTURAL PRODUCTS
Current assignee: BURGESS ARCHITECTURAL PRODUCTS
Priority date: 2003-10-13
Filing date: 2003-10-13
Publication date: 2005-05-11
Anticipated expiration: 2023-10-13
Also published as: GB0323986D0; GB2407826B

Abstract

A ceiling grid 1 system has a main member 2 which extends in a first direction, and a cross member 4 which joins the main member at an angle. The members each having a slot 14 in an underside of the member and extending lengthwise of the members. The slots are ribbed to receive fixing members for demountable partitions. The cross member 4 has a flat end face 50 which abuts a flat side 32 of the main member 2 to form a butt joint, and a recess 38 is provided in a side wall 18 of the slot 14 in the main member at the junction with the cross member. The recess is equal to the width of the slot in the abutting cross member, to provide a continuation of the slot through the side wall 18 to join the slot 14 in the main member 2. A pin 30 extends through the main member 2 above the level of the slot 15 and projects into a slot 28 in the cross member to locate the cross member.

Description

Ceiling Grids The present invention relates to a ceiling grid. Ceiling

grids typically comprise a grid formed of interconnected metal extrusions. The grid is suspended from the structural ceiling of a building and supports ceiling tiles, lighting units and the like.

One difficulty with such grids is the provision of a connection between the grid members, particularly at angled junctions between the members. One type of grid system is shown in GB-A-2172028 and has elongate main members which can extend for several metros in one direction. These are joined by cross members at spaced intervals along the length of the main members.

Another popular style of grid system uses extruded aluminium grid members. Typically the grid members are carried on main steel backing supports which run substantially continuously in one direction and clip together end to end. The backing supports are suspended from the structural ceiling by wires or the like, as well known in the art. The backing supports for the cross members have tongues which extend though slots in the backing supports for the main member to hold the members together and resist lateral movement. The depth of the backing supports provides vertical strength to prevent sagging and the use of steel backing supports provides enhanced fire resistance for the structure. In some systems the backing support is integrally formed with the grid member.

The grid members may have a ribbed or fluted channel in the exposed underside of the installed grid, the ribs running the length of the channel to receive threaded fixings for locating Remountable partition walls in the room space. GB-A-2167779 shows one such system, with the grid members ending at a junction and connected by a cruciform connector which extends into axially extending apertures in the grid members. A problem posed by this design is the desirability of maintaining continuity of the slot at the angled junctions between the grid members. A continuous slot facilitates fixing of the partition and improves the aesthetic appearance of the grid. GB-A-2245010 shows grid members connected at mitred joints, again with a connector extending into axial apertures in the abutting ends of the extrusions. With these designs none of the grid members extends continuously in one direction. This results in a system requiring assembly of many short lengths. GB-A-2152091 shows a system with main members extending substantially continuously in one direction (i.e. for more than the length of one unit of the grid) and cross members butted to the main member at a mitred joint.

Mitred joints are difficult to cut and achieve a close fit.

in GB-A-2286836, a plastic connector is used. The connector clips in a recess cut in the underside of the main member. Arms on the connector extend laterally of the main member into axial apertures in the ends of the cross members. This allows for square cuts of the members. Appropriate design of the plastic connector maintains the appearance of a continuous channel. However, the plastic members are expensive to produce and must be coloured to match the finish of the grid members.

A first aspect of the present invention provides a ceiling grid system comprising a main member which extends in a first direction, and a cross member which joins the main member at an angle, the main member and the cross member each having a slot in an underside of the member which is visible in use, the slots extending lengthwise of the members, wherein the cross member has a substantially flat end which abuts a side of the main member, and a recess is provided in a side wall of the slot in said main member at the junction with the cross member, the recess being substantially equal to the width of the slot in the abutting cross member, to provide a continuation of the slot through the side wall to join the slot in the main member.

The flat end of the cross member may be formed square to the underside of the cross member.

Where the inner side surfaces of the slots are ribbed, to provide a fixing for a threaded stud or the like, the recess in the slot sidewall of the main member may also be cut with ribbed side surfaces. Typically the members are extruded. The slot sidewalls are preferably solid, the cross member abutting the outer side surface of the slot sidewall of the main member, thus providing a continuous ribbed surface at the junction of the members.

Preferably the main member and cross member are aligned by means of a pin which extends through a transverse aperture or slot in the main member in to an axially extending slot or aperture in the cross member. Preferably the aperture in the main member and the cooperating slot in the cross member are positioned above the respective channels so that the pin is not visible in the assembled grid from below.

Preferably the main member and cross member have the same cross section.

Typically the grid is square or rectangular and the cross member abuts the main member at right angles, the end face of the cross member being square to the underside and the side surfaces of the cross member. Where two cross members abut the main member on opposite sides at the same position, the pin may extend through the main member to locate in the apertures or slots in both cross members. A stop may be formed on the pin to limit the movement of the pin through the aperture or slot in the main member. This may also serve to limit the movement of the pin into the aperture or slot in the adjacent cross member, to prevent the pin being pushed back into the cross member as the other cross member is slid onto the pin.

With grid type ceiling systems it may be difficult or undesirable to run the grid members along the room wall and it is known to provide one of a range of finishes at the ceiling edge, adjacent the room walls, such as a plasterboard trim or shadow trim. It is desirable to suspend a support for such an edge finish from the ceiling grid system.

Another aspect of the present invention provides a ceiling grid member having a channel along a side of the member, the channel having ribbed sidewalls to receive a threaded fixing member.

Other aspects and preferred features of the invention will be apparent from the

following description and the accompanying claims.

The invention will be further described with reference to the accompanying drawings in which, Figure I is a schematic view from underneath of an assembled ceiling grid system.

Figure 2 is an exploded perspective view of a junction between a main member and a cross member of a ceiling grid system forming an embodiment of the invention; Figure 3 is a view of the junction of Figure 2, with the members abutting; Figure 4 is a cross section through a main member and showing a pin; Figure 5 is a cross section through a grid member and a separate backing support; Figures 6a, 6b and 6c show a connection between two main members of Figure 1; Figure 7 is a cross-section showing a fixing for a partition, and Figure 8 shows a fixing for a plasterboard trim.

Referring to Figure 1, this shows schematically an assembled ceiling grid system 1 in the form of a rectangular grid for receiving square ceiling panels and the like (not shown). Main grid members 2 extend substantially continuously in one direction. In practice the main grid members will be a few metres in length and extend for several panel sections. Cross members 4 extend between adjacent main members 2. The members 2, 4 have integral backing supports 6 which provide enhanced rigidity against sagging in the vertical direction. The grid is suspended from a ceiling 8 by wires 10 or the like, as well known in the art. A ceiling tile or lighting panel will rest on upper sides of the grid members, filling the space between them (refer to Figure 7).

Referring to Figures 2 and 4, a main member 2 and a cross member 4 have the same cross section and are of extruded aluminium. Extrusions are cut to length to form the main members and cross members. The members may be cut to length from the same extrusion. Other materials may be used, such as plastics, to suit the particular requirements.

Each member has a body portion 12 and a backing support 6 extending from the body portion. Backing support 6 resists any vertical bending load on the member 2, 4. Body portion 12 has a channel 14 formed on an underside surfacel6. Side walls 18 ofthe channel 14 are solid. Inner side surfaces 20 of the channel 14 have ribs 22 to enable a threaded stud or other fixing to be screwed into the channel 14 as well known in the art and as will be described hereinafter. A plain sided channel or other crosssection may be used, with other appropriate fixing members.

Above bottom wall 26 of the channel 14 a slot 28 is provided. In the cross member 4, this slot receives a cylindrical pin 30. Slot 28 is of generally circular cross-section, extending over about 270 degrees so as to snugly receive the pin 30. Slot 28 could also be in the form of a circular cross section through bore.

Side surfaces 32 of the body 12 have a longitudinally extending channel 34 similar to channel 14, with ribs 36 formed on the inner side surfaces of the channel 34.

Ribs 22, 36 on opposed inner side surfaces of the channels 14, 34 are staggered and dimensioned to receive a standard screw thread such as M6.

Above slot 28, the profile is hollow to reduce the amount of material used in the extrusion.

Shown part way along the length of the main member 2 is a recess 38. Recess 38 is formed in the sidewalls 18 and has ribs 40 on the inner side surfaces to match the ribs 18 of the co-operating cross member 6. Above bottom wall 26 of channel 14, an aperture 42 is provided through the bottom walls 44 of the channels 34 and passing though the intervening slot 28.

The width of the recess 34 is the same as the width of the channel 14 of the abutting cross-member 4. In this example, cross member 4 abuts main member 2 at right angles (Figure 3) and the recess extends at right angles to the side surfaces of the body 12. To locate the cross member adjacent the main member 2, an end 46 of pin 30 is inserted through aperture 42 until circumferential rib 48 rests against the bottom wall 44 of the channel 34 facing the cross member 4.

Cross member 4 has an end face 50 which is square, i.e. at right angles, to the side surfaces 32 and lower surface 16 of the cross member 4. Slot 28 of the cross member 4 is then slid onto the other end 52 of the pin 30 to abut the side surface of the main member 4. The pin thus locates the cross member in position along the main member and in the same plane as the main member.

As seen in Figure 4, pin 30 is dimensioned to project beyond the side surfaces of the main member body 12 to receive a pair of cross members, on opposite sides of the main member. When the main member is at an edge of the grid, the unused pin end is likely to be hidden, or it can be cut away. If desired, the recess in the side wall 18 distal of the cross member may be filled with a plug.

When a second cross member 4 is slid on to the pin end 46, rib 48 prevents the pin being pushed back into the slot 28 of the first cross member.

The cross-section of the pin 30, the slot 28 and the aperture 42 may be shaped to prevent rotation of the cross member about the pin and relative to the main member. A square or other polygonal cross-section may be used, for example.

It will be appreciated that the aperture for receiving the pin in the main member could be a slot such as a keyhole slot cut in main member upper surface, the requirement is to locate the pin in the main member. Also, although we prefer to provide a slot in the cross member to receive the pin as this facilitates the extrusion process, another shape aperture or recess could be provided.

It can be seen that the fixing system provides for visual continuity of the channel 14 from one cross member through to the other.

Figure S shows a cross-section of a main member 2'or cross member 4' without an integral backing section 6. Here, backing section 6' is formed of folded steel sheet and has a lower flange 56 which slides into slots 58 formed in the upper surface of the body 12.

Referring to Figure 3, the main member 2 has apertures 42 and recesses 38 spaced at regular intervals along the length of the main member. The spacing is chosen to suit the required grid pattern, and typically spacing of 500mm, 600mm or 750 m are used. For a square grid the corresponding cross members will be slightly shorter than the centre to centre spacing of the apertures to compensate for the width of the main member. The apertures 42 and recesses 38 are cut, for example by drilling or milling, in the main member extrusion at the factory. As the cut surfaces of the recess 38 may be visible on the installed grid, it may be preferable to delay applying the finish, such as painting, to the grid members until after this cutting operation is finished.

Referring to Figures 6a, 6b and 6c, these show one manner of aligning two main members 2'a, 2'b which are connected together end to end. The same arrangement can be used for connecting main members 2 which have an integral backing support. The members 2' are connected at the location of a recess 38, one member (Figure 6a) is cut at an edge of the recess 38, and a slot 62 is cut to connect the aperture 42 with the end face 60 of member 2'a. Member 2'b may have a plain end, as shown, or may be cut at a lot edge to provide a ribbed end surface. To align the members 2'a, 2'b an alignment pin30' is provided. Pin 30' so of cruciform shape, wit two stub axles 64 extending at right angles to the main pin body axis. The pin 30' is forced into the aperture 42 through slot 28 in member 2'a, and the other stub 64b extends proud of the end face 60 to projects into aperture 28 in member 2'ccb.

It will be appreciated that the members 2'a, 2'b could be joined at a position between the recesses 38, and located relative to one another by a plain pin which extends ion the respective slots 28.

Figure 6c shows two backing supports 6'a, 6'b which overlap at a tongue 65 to connect them via a detent66 as known in the art.

Members 2 may be connected in a similar fashion, the backing supports being joined by a splice member as describe d above.

When a separate backing support is used, the profile for such supports is well known, as are mechanisms for locking supports together end to end when extending supports along a main member, and also for locking the cross member backing supports to the main member supports.

In the assembled grid, the pins 30 provide for accurate location of the grid members relative to one another. Any tendency of the grid members to rotate about the pin members is prevented by the backing supports which also carry the main weight of the grid members and the ceiling panels members With the embodiment of Figure 2, channels 70 are formed along the upper and lower edges 72, 74 of the backing support 6 to receive a splicing member (not shown).

Splicing member may take the form of a flat plate which slides into the channels 70 so as to locate two members end to end, preventing relative rotation of the members. The splicing member may be held in place by a detent or a fixing such as a screw to prevent axial separation of the main members.

A cross member may be further located on the main member using a right angled splicing ember. One leg of the splicing member extends along the backing support of the main member, and the other leg projects into the slots 72, 74 of the cross member 4.

Referring to Figure 7, this shows a grid member 2', 4' with two ceiling tiles 80 resting on the body of the cross member. A partition 82 is held in place by an inverted channel 84 which is fixed to the underside of the grid member by a stud 86.

Referring to Figure 8, this shows a plaster board finish at an edge of the ceiling grid. A support member 90 is mounted on the side face of the grid member 2', (4') by a stud 86' which extends through an aperture in the support member and screws into the side channel 34. A plasterboard panel is secured on the support member 90 and a finish coat 94 of plaster then applied.

Various modifications will be apparent to those in the art and it is desired to include all such modifications as fall within the scope of the invention described herein.

Claims

CLAIMS: 1. A ceiling grid system comprising a main member which extends in

a first direction, and a cross member which joins the main member at an angle, the main member and the cross member each having a slot in an underside of the member which is visible in use, the slots extending lengthwise of the members, wherein the cross member has a substantially flat end which abuts a flat side of the main member to form a butt joint, and a recess is provided in a side wall of the slot in said main member at the junction with the cross member, the recess being substantially equal to the width of the slot in the abutting cross member, to provide a continuation of the slot through the side wall to join the slot in the main member.
2. A ceiling grid system as claimed in claim I, wherein inner side surfaces of the slots are provided with ribs, to provide a fixing for a threaded stud or the like.
3. A ceiling grid system as claimed in claim 2, wherein inner side surfaces of the recess in the slot sidewall of the main member are provided with ribs.
4. A ceiling grid system as claimed in claim I, 2 or 3, wherein the slot sidewalls are solid, the cross member abutting the outer side surface of the slot sidewall of the main member.
5. A grid system as claimed in any one of claims 1 to 4, wherein the grid is square or rectangular and the cross member abuts the main member at right angles, the end face of the cross member being square to the underside and the side surfaces of the cross member.
6. A ceiling grid system as claimed in any one of claims 1 to 5, wherein the main member and the cross member have the same cross-section.
7. A ceiling grid system as claimed in any one of claims 1 to 6, wherein the main member and cross member are aligned by means of a pin which extends transversely through the main member and into the cross member.
8. A ceiling grid system as claimed in claim 7, wherein the pin extends through an aperture in the main member and into a cooperating formation in the cross member which are positioned above the respective channels so that the pin is not visible in the assembled grid from below.
9. A ceiling grid system as claimed in claim 7 or 8, wherein a stop is formed on the pin to limit the movement of the pin through the aperture in the main member.
l O. A ceiling grid system comprising a main member which extends in a first direction, and a cross member which joins the main member at an angle, wherein the cross member abuts a side of the main member to form a join, wherein the cross member is aligned with the main member by means of a pin which extends transversely of the main member and engages the cross member.
11. A ceiling grid system as claimed in claim l O wherein the pin extends through an aperture in the main member.
12. A ceiling grid system as claimed in claim 10 or 1 1, wherein the pin extends into a cooperating slot in the cross member.
13. A ceiling grid system as claimed in claim 10, l l or 12, wherein a channel is provided in an underside of the cross member and the pin is positioned above the respective channels so that the pin is not visible in the assembled grid from below.
14. A ceiling grid system as claimed in any one of claims 10 to 13, wherein a stop is formed on the pin to limit the movement of the pin relative to the main member.
15. Aceilinggrid as claimed in anyone ofclaims 1 to 14, whereinachannel is provided along a side of the member, the channel having ribbed sidewalls to receive a threaded fixing member.
16. A ceiling grid member having a channel along a side of the member, the channel having ribbed sidewalls to receive a threaded fixing member.