A LIGHTING ASSEMBLY AND BRACKET THEREFOR
The present invention relates to a lighting assembly for use in areas where there is a suspended ceiling and, in particular, to a bracket for such a lighting assembly.
Conventionally, when an area has a suspended ceiling the light fittings are arranged so that their lower edges are flush with the ceiling and the components making up the fitting are recessed above the ceiling. In this way most of the components making up the fitting are hidden leaving only the actual light, a reflector and perhaps a louvre or light diffuser on show. In strip lighting arrangements when fluorescent or other forms of tube lighting is to be used, the light fittings usually comprise a series of rectangular fabricated metal housings in which the lights, a reflector and all the electrical control gear and wiring for the lights are mounted. Functional or decorative louvres or diffusers may then be used to cover the lights and rest on flanges formed across the lower open side of the housings.
Usually, the use of such light fittings is planned along with the plans for the suspended ceiling itself and they are installed prior to the suspended ceiling, which is then built around the suspended fittings.
In buildings with a large ceiling area, in order to install a suspended ceiling a rigid sub-grid is first suspended from the ceiling soffit and it is to this sub- grid that the suspended ceiling and light fittings are connected. Typically, the sub-grid comprises a horizontal grid of beams, usually of C-section to reduce weight, which are suspended by screw-threaded rods so that the beams can be exactly levelled at the same height. The suspended ceiling elements and the light fittings are then attached to the sub-grid by means of brackets which are bolted to
the beams .
It will be appreciated that the installation of the suspended ceiling and lighting arrangement can be awkward in view of the height of the working environment. Hence, it is 'advantageous to make the means of attachment of the brackets to the sub-grid and the light fittings to the brackets as easy to accomplish as possible.
It is, therefore, an object of the present invention to provide a bracket and a lighting assembly which are easier to attach to the sub-grid than those used hitherto.
According to a first aspect of the present invention there is provided a bracket for a lighting assembly for use with a suspended ceiling arrangement characterised in that it comprises a hooked portion to enable it to be located over and depend from a sub-grid of the ceiling arrangement and a plate defining at least one open-ended slot, which is substantially horizontal in use and into which a flange of the lighting assembly can be fitted, and a tag located adjacent the open end of the slot which can be bent from a first position wherein it projects from the plane of the plate into a second position coplanar with the plate to cover the open end .of the slot and thereby retain the flange in position in the slot.
Preferably, the bracket comprises two opposed slots which are aligned on opposite sides of the plate. Preferably also, when the tag is in its second position coplanar with the plate it is spaced from one edge of the slot so that the slot is extended by a portion which is at right angles thereto and which is defined by the opposed edges of the tag and the plate.
Preferably also, the plate comprises at least one lug
which can be bent from a first position wherein it is coplanar with the plate into a second position wherein it projects from the plate and which can be used to assist in the retention of the plate against the sub-grid of the ceiling arrangement at least whilst the lighting assembly is being assembled.
Preferably also, the plate defines a hole so that the bracket can be secured to the sub-grid by means of a bolt or screw.
According to a second aspect of the present invention there is provided a lighting assembly incorporating a bracket according to the first aspect of the present invention.
Preferably, the lighting assembly comprises at least one pair of opposed parallel support plates, each of which is provided with a flange located respectively in one of the open-ended slots defined by the bracket.
Preferably also, the flange of each support plate projects outwardly at right angles thereto so that the flange locates in the slot defined by the bracket and the support plate locates in the right angled extension to the slot defined by the opposed edges of the tag and the plate of the bracket.
Preferably also, each support plate comprises a runner which in use oppose one another and on which a light fitment incorporating electrical components including at least one light socket can be slid into position between the support plates.
Preferably also, each support plate comprises a tray parallel with the runner and into which electrical wiring
for the light can be located.
Preferably also, between consecutive light fitments of the lighting assembly are located frameworks connected to the support plates into which frameworks can be located infil plates or other ancillary components for the lighting assembly
Preferably also, along the lower edge of each of the support plates is a flange which in use supports a louvre or diffuser arrangement covering the light fitment.
Preferably also, a pair of aligned louvre or diffuser arrangements are used to cover a single light fitment, an infil bracket being located between the louvre or diffuser arrangements and connected to the support plates in order to regulate the width between the support plates.
The present invention will now be described by way of example with reference to the accompanying drawings in which:-
Figures 1, 2 and 3 are side, end and plan views respectively of a bracket for a lighting assembly according to the first aspect of the invention;
Figure 4 is an end view of a lighting assembly according to the second aspect of the invention when almost completely assembled as part of a suspended ceiling arrangement;
Figures 5A,5B and Figures 6A,6B are views from below and from the side of an infil bracket and an infil framework respectively which both form part of the lighting assembly shown in Figure 4; and
Figures 7A and 7B are views from below and from the side respectively of an infil plate for use with the infil framework shown in Figures 6A and 6B.
The bracket according to the first aspect of the invention can either be fabricated in one piece from sheet metal or be cast and comprises a substantially trapezoidal plate 1 and a hooked portion 2 formed along the edge of the shorter parallel side of the plate 1.
The hooked portion 2 comprises a hook 3 which is substantially at right angles to the plate 1 and which is provided with an inturned lip 4. The overall cross- sectional shape of the portion 2 is such that it can be located over the upper side and open top edge of a C- section beam to enable the plate 1 to depend vertically from the beam adjacent its own vertical side. In this way, the bracket can be attached to a beam of a sub-grid of a suspended ceiling and lighting arrangement.
In order to enable the bracket to be more stable whilst a lighting assembly is attached thereto, as described below, the bracket is provided with at least one lug 5 which projects from the longer of the two parallel edges of the plate 1. Initially, the lug 5 is coplanar with the plate 1 and along the boundary between the plate 1 and the lug 5 is cut a series of aligned slots 6. The slots 6 enable the lug 5 to be bent along the boundary out of alignment with the plate 1 into a position in contact with the C-section beam of the sub-grid. This holds the bracket firmly against the beam until it is permanently secured thereto, for example by means of a self tapping screw or a bolt which is located through a hole 7 formed in the centre of the plate 1, after the lighting assembly supported by the bracket has been assembled and correctly aligned so that the final position of the bracket in relation to the
beam has been found.
At opposed sides of the longer of the two parallel edges of the plate 1 are substantially rectangular extensions 8 to the plate 1. Along part of the boundaries between these extensions 8 and the plate 1 are two opposed open-ended slots 9, which are aligned and parallel to the slots 6. Attached to the plate 1 adjacent the open end of each slot 9 is a tag 10. The tags 10 initially project outwardly from the plate 1 on the side opposite the hooked portion 2 so that they do not impede the attachment of the bracket to the sub-grid. However, the tags 10 can be bent to lie coplanar with the plate 1 to cover the open ends of the slots 8. The tags 10 are spaced slightly from the ends of the slots 9 so that when they are coplanar with the plate 1 the slots 8 are extended by a portion at right- angles thereto which is defined by the opposed edges 11 and 12 of the tags 10 and the plate 1 respectively.
In use, when the bracket is suspended from a beam of a sub-grid of a suspended ceiling and lighting arrangement, the slots 9 are used to hang a pair of opposed parallel support plates 13 of a lighting assembly from the bracket. The construction of such an assembly will now be described with reference to Figures 4 to 7.
The lighting assembly according to the second aspect of the invention comprises strip lighting incorporating a series of light fitments with their associated electrical components and light sockets and a suspension means to enable the fitments to be mounted into a suspended ceiling arrangement.
The suspension means comprises the pair of support plates 13 and at least two brackets 14, as described above with reference to Figures 1 to 3. The brackets 14 are used
to suspend the support plates by means of outwardly turned flanges 15 formed along the top edges of the plates 13 which are fitted into the slots 9, as described above, before the tags 10 of the brackets 14 are bent downwards to lock the plates 13 thereto. In practice, a plurality of brackets 14 are used to secure one pair of plates 13, spaced at appropriate intervals along the length of the plates 13 dependent on the spacing of the beams 16 of the sub-grid. The pairs of plates 13 or a series of aligned pairs of plates 13 are suspended in a strip across the ceiling soffit where it is desired to locate the light fitments themselves.
The support plates 13 each comprise a runner 17 which projects inwardly of the plates 13 on the opposite side thereof to the flange 15. The opposed runners 17 are used to retain the light fitments comprising gear trays 18, which are slid into position along the runners 17. Each gear tray 18 is an inverted tray provided with reflecting surfaces 19 and in which are located sockets 20 to hold lights (not shown) such as fluorescent tubes. Above the gear tray 18 under a cover 21 is located conventional electrical control gear for the lights. The wiring for the lights is also retained by the plates 13 in cable trays 22 which are attached to the plates 13 parallel to and above the runners 17. The trays 22 are closed by lids 23. As shown in Figure 4, the runners 17 and the cable trays 22 for each plate 13 can be made from a one-piece extrusion of appropriate shape which is suitably attached to the plate 13. Alternatively, a plate 13 and its associated runner 17 and cable tray 22 can be extruded in one piece.
Covering the lights and resting on opposed inturned flanges 24 formed along the lower edges of the plates 13 is a series of arrangements each comprising a diffuser or louvre 25. A pair of aligned louvres 25 is provided to
cover the lights held by the sockets 20 on the gear tray 18. Between each louvre 25 of a pair is located a substantially H-shaped infil bracket 27 as shown in Figures 5A and 5B. The legs 28 of the bracket 27 are connected to the plates 13. In this way, the brackets 27 ensure that the plates 13 of each pair are correctly spaced relative to one another along their length.
At the end of each gear tray 18 between lights is located an infil framework 30 as shown in Figures 6A and 6B. This is also connected to the pairs of plates 13 and also assist in holding the plates 13 rigidly in position. The space defined by the frameworks 30 between the plates 13 can be used for a variety of purposes, for example to house ancillary equipment for or components of the lighting assembly. If nothing is to be incorporated into the assembly which is to be seen from below at the positions of the frameworks 30, then they are closed off by infil plates 31, as shown in Figures 7A and 7B, which are fastened into the frameworks 30 so that the assembly presents a finished appearance. Preferably, the plates 31 clip into the frameworks 30 using spring clips (not shown) so that they can be easily removed and replaced when necessary. It will be appreciated that the plates can be replaced by or adapted to incorporate optional features of the lighting assembly or suspended ceiling arrangement ceiling as required. For example, emergency lighting or suspended illuminated signs could be provided in these areas which can also make use of the cable trays 22 provided in the plates 13.
Once the lighting assemblies for a ceiling area have been installed, a suspended ceiling arrangement can then be assembled around them. As shown in Figure 4, such an arrangement 32 is butted up to the plates 13 and, dependent on the ceiling arrangement in question, attached thereto.
It will be appreciated that in use the brackets 14 according to the first aspect of the invention are easy to install and use. They can be quickly located in the correct positions on the sub-grid of the ceiling arrangement and the support plates 13 of the lighting assembly are simply slotted sideways into engagement therewith, without the use of screws or bolts. This saves time and effort and greatly facilitates the assembly of the light fittings, particularly given the difficulties associated with working at heights when installing a suspended ceiling and lighting arrangement. In addition, the lighting assembly as a whole is designed to be installed easily with a minimum of fixings.