WO2000025063A2

WO2000025063A2 - Lighting apparatus

Info

Publication number: WO2000025063A2
Application number: PCT/GB1999/003576
Authority: WO
Inventors: John David Hopper; Marjorie Hopper; Neill Derek Hopper; Nicola Hopper; Joanna Marjorie Israel; Naim Israel
Original assignee: John David Hopper; Marjorie Hopper; Neill Derek Hopper; Nicola Hopper; Joanna Marjorie Israel; Naim Israel
Priority date: 1998-10-28
Filing date: 1999-10-28
Publication date: 2000-05-04
Also published as: GB2358462A; WO2000025063A3; GB0110201D0; AU6360099A; GB9823482D0; GB2358462A8

Abstract

Lighting apparatus for use with fluorescent tubes. The apparatus disclosed is suited particularly for use with T5 type fluorescent tubes. Certain aspects of the invention relate to lighting units employing an extruded box-section housing providing the basis for a variety of types of light fittings and modular track-type lighting systems. Other aspects relate to light fittings and kits-of-parts enabling existing lighting installations employing, for example, T8 type fluorescent tubes to be converted for use with improved types of fluorescent tubes, such as T5 type.

Description

"Lighting Apparatus"

The present invention relates to fluorescent lighting apparatus .

The invention is particularly concerned with providing light fittings and associated apparatus suited for use with "T5" type fluorescent tube lights and associated electrical gear. T5 lighting systems employ 16 mm diameter fluorescent tubes. The tubes and electrical gear provide improved efficiency in terms of light output and energy consumption in comparison with earlier fluorescent lighting systems (e.g. "T8" 28 mm tubes and gear) and longer lamp life. Existing lighting apparatus for use with existing T8 and other fluorescent lights is not suited for use with T5 technology. The present invention is concerned with providing lighting apparatus enabling the advantages of T5 lighting technology to be exploited. However, certain aspects of the invention may be used advantageously with other fluorescent lighting systems.

Several problems are encountered if T5 lighting tubes are to be mounted within existing T8 light housings. One such problem is positioning the T5 lamp tubes to compensate for their smaller diameter. The T5 tubes would otherwise generate light from a different focal point than the original lamp tubes and so glare and light output would not be optimised for the smaller T5 lamp tube diameter.

The smaller size of the T5 tube ends and components and different power consumption and heat generation factors can also create problems when attempting to upgrade existing light fittings to the new T5 technology. In one aspect, the invention seeks to obviate or mitigate the above problems by providing apparatus to modify existing light fittings to utilise T5 lighting technology. The invention also seeks to provide a means for controlling the power distribution in a T5 lighting system.

In other aspects, the invention seeks to provide improved lighting apparatus, particularly but not exclusively intended for use with T5 lighting technology.

In accordance with a first aspect of the invention, there is provided a light fitting for at least one fluorescent tube lamp comprising an elongate, box- section main body unit consisting of: a base member, a cover member, end cap members and lamp holders spaced along the length of the main body for receiving a fluorescent tube therebetween.

Preferably, the base member and the cover member comprise extruded members of uniform transverse cross- section.

In certain embodiments the lamp holders are located on an external surface of said cover member so that the lamp is mounted externally of the main body unit; and further comprising control gear for the lamp located within the body unit, wherein the light fitting further includes a reflector assembly extending along the length of the cover member.

Preferably, the light fitting further includes a valance assembly secured to the cover member and having removable trim panels which extend along the length of the light fitting externally of said reflector assembly.

Preferably, the valance assembly further includes end cap members adapted to cover the ends of the main body unit and of the reflector assembly.

The light fitting may further include lamp holders spaced along one side of said base member for receiving a further fluorescent tube therebetween.

In other embodiments, the lamp holders are enclosed within the base member and the cover member includes an aperture fitted with a light diffusing member.

In accordance with a second aspect of the invention there is provided a modular lighting system comprising: lighting units, each for at least one fluorescent tube lamp, the lighting units comprising an elongate, box-section main body unit consisting of a base member, a cover member including an aperture fitted with a light diffusing member, end cap members and lamp holders contained within and spaced along the length of the main body for receiving a fluorescent tube therebetween; control units, each comprising an elongate, box- section main body unit consisting of a base member, a cover member and end cap members, and lighting control gear contained within the main body for controlling operation of the lighting units, said control units having a similar cross-sectional configuration to said lighting units; said lighting and control units being adapted to be connected together end to end to form a lighting track.

Preferably, said lighting and control units each include plug means at one end thereof and socket means at the other end thereof, and electrical bus means connecting said plug and socket means, whereby adjacent units may be connected together by inter-engagement of their respective plug and socket means and whereby electrical power may be distributed amongst the connected units.

Preferably, said bus means includes a first mains supply bus having a first plug and a first socket associated therewith, and a lamp supply having a second plug and a second socket associated therewith.

Preferably, each control unit is adapted to control the operation of first and second lighting units, one of said lighting units being connected to each end of the control unit.

Preferably, the system further includes corner units comprising angled, box-section main body units consisting of a base member, a cover member and end cap members, and including plug and socket means at either end thereof and electrical bus means connecting said plug and socket means, said corner units having a similar cross-sectional configuration to said lighting and control units.

Preferably, the base members and cover members of the various units comprise extruded members of uniform transverse cross-section.

Most preferably, the extrusions are substantially identical to those employed in the first aspect of the invention.

In accordance with a third aspect of the invention, there is provided lighting duct apparatus comprising a pair of end pieces spaced apart and adapted to support an elongate light fitting therebetween such that the light fitting may be rotated about its longitudinal axis to any required orientation relative to the end pieces, and duct panels connected to the end pieces to enclose the light fitting.

Preferably, the end pieces are connected together by a first duct panel portion, the remainder of the duct being formed from further panel portions.

Preferably, the end pieces are polygonal (most preferably hexagonal) and the duct panels are generally planar and are connected to respective sides of the end piece.

Alternatively, the end pieces are circular and are interconnected by an arcuate section base portion, the remainder of the duct being formed from a further arcuate section portion which is rotatable between the end pieces, the further arcuate section being adapted to receive the elongate light fitting therein.

Preferably, the elongate light fitting comprises a light fitting in accordance with the first aspect of the invention.

In accordance with a fourth aspect of the invention, a light fitting comprising a body adapted to be mounted to or recessed in a ceiling, a gear tray including a plurality of lamp holders and associated electrical components adapted to be mounted within the body, and a louvre assembly comprising at least one main louvre located in at least one aperture formed in a secondary louvre grid, whereby said at least one main louvre occupies a proportion of the surface area of the light fitting and the remaining surface area is covered by said secondary louvre grid.

In accordance with a first aspect of the invention, there is provided a kit of parts for use in converting an existing light fitting of the type comprising: a body adapted to be mounted to or recessed in a ceiling; a gear tray adapted to be mounted within the body and including a plurality of lamp holders for holding fluorescent tubes of a first type having a first diameter and associated electrical components, and louvre means associated with said lamp holders; said kit of parts including: a replacement gear tray adapted to be mounted within the body and including a plurality of lamp holders for holding fluorescent tubes of a second type having a second diameter less than said first diameter and associated electrical components.

In one embodiment, the kit further includes a louvre assembly for replacing said louvre means, said louvre assembly comprising at least one main louvre located in at least one aperture formed in a secondary louvre grid, whereby said at least one main louvre occupies a proportion of the surface area of the light fitting with which the kit is intended to be used and the remaining surface area is covered by said secondary louvre grid.

Alternatively, said replacement gear tray is adapted for supporting said lampholders in such a manner that, in use, said fluorescent tubes of said second type are located in substantially the same position relative to said louvre means as said fluorescent tubes of said first type.

Said replacement gear tray and lampholders may be adapted for use with circular fluorescent tubes and further including diffuser means adapted for use with said circular fluorescent tubes.

In accordance with a sixth aspect of the invention, there is provided a lighting system comprising a plurality of light fittings in accordance with the preceding aspects of the invention and including at least one distribution box for use in distributing power between said plurality of light fittings, said distribution box having at least one power supply input and a plurality of outputs connected to said at least one input.

Preferably, said inputs and outputs of said distribution box comprise plug/socket connectors.

Preferably, said distribution box includes electronic control means for switching and/or dimming light fittings connected to said outputs.

Optionally, said electronic control means is adapted to be remotely controllable.

The invention will now be described by way of example only and with reference to the accompanying drawings in which:

Fig. 1 shows a perspective view of the main components of an embodiment of a light fitting according to the first aspect of the invention.

Fig. 2A shows a perspective view of a lamp body, cover and end cap of the light fitting of Fig. 1.

Fig. 2B shows a perspective view of the section of the lamp body cover of Fig. 2A.

Figs. 3A and 3B show perspective views of valance apparatus for use with the light fitting of Fig. 1.

Figs. 4A, 4B and 4C show perspective views of various end caps for use with the valance apparatus of Figs. 3A and 3B.

Fig. 5 is an exploded perspective view showing how the valance apparatus and end caps are attached to the main light fitting.

Figs. 6A, 6B and 6C show perspective views of complete light fittings embodying the first aspect of the invention.

Figs. 7A, 7B show transverse cross-sections of light fittings embodying the first aspect of the invention.

Fig. 8 shows a perspective view of a plurality of modules of a modular lighting system embodying the second aspect of the invention.

Figs. 9A shows a perspective view of a first internal corner unit for use in the system of Fig. 8.

Figs. 9B and 9C show perspective views of external corner units for use in the system of Fig. 8.

Fig. 10 shows a cut-away perspective view illustrating an arrangement for establishing electrical connections between adjacent modules in the system of Fig. 8.

Fig. 11 shows a perspective view of a gear-tray for a control unit forming part of the system of Fig. 8.

Fig. 12 shows an exploded perspective view of a track lighting unit forming part of the system of Fig. 8.

Fig. 13 shows various views of a modular lighting duct system according to third aspect of the invention.

Fig. 14 is an exploded perspective view of an embodiment of a light fitting according to a fourth aspect of the invention.

Fig. 15 is a perspective view of another embodiment of a light fitting according to a fourth aspect of the invention.

Fig. 16 is a plan view of a first embodiment of a secondary louvre grid for use in light fittings in accordance with the fourth aspect of the invention.

Fig. 17 is a plan view of a second embodiment of a secondary louvre grid for use in light fittings in accordance with the fourth aspect of the invention. Figs. 18A, 18B and 18C are, respectively, side, end and plan views of an example of parabolic reflector assembly ("louvre") as employed in various aspects of the invention.

Fig. 19 is a perspective view of another embodiment of a light fitting according to a fifth aspect of the invention.

Figs. 20A to 20C show various views of height adjusting inserts mounted upon a gear tray in the embodiment illustrated in Fig. 19.

Fig. 21 shows a perspective view of an alternative gear tray according to one embodiment of the fifth aspect of the invention.

Figs. 22A, 22B, 22C, 22D, 23A, 23B, 23C, 24A, 24B show various light fittings according to the invention.

Fig. 25 shows a sectional end view of a light fitting of the type illustrated in Figs. 22A to 22D, 23A, 23B, 24A, and 24B.

Fig. 26 shows perspective views of circular lamp fittings according to an embodiment of the invention.

Figs. 27A to 27D and 28A to 28D show various views of components and casings for distribution boxes according to a sixth aspect of the invention.

Referring now to the drawings, Figs. 1 to 7 illustrate embodiments of a first type of light fitting in accordance with the invention. This is a "stand-alone" fitting for a single fluorescent tube, suited for attachment to ceilings or walls and for orientation in any desired position; i.e. as a downlight, uplight or angled light. These embodiments can also be readily modified to provide double lamp fittings.

Fig. 1 shows a stand-alone light fitting 10 according to a first preferred embodiment of the present invention. Light fitting 10 comprises a main body unit 12 and a reflector assembly or "louvre" 14. Both the lamp body unit 12 and the louvre fitting 14 may be formed from suitable materials such as aluminium or plastics, and may be coated with various finishes, including coloured or chrome finishes .

The main body unit 12 preferably comprises an extruded aluminium base or gear tray 16 and a front cover 18, which together provide an elongate box-section casing. Gear tray 16 has back access apertures 20, 22a and 22b to enable wiring to enter the interior of the main body unit 12 and/or to provide fixing points for attaching the body unit 12 to a ceiling or wall or for the attachment of suspension tubes, mounting brackets etc. The base extrusion 16 holds the lamp ballast and all wiring circuits are completely contained within the main body 12. At each end of longitudinal axis X-X' of the main body unit 12, end caps 24 are provided. End caps 24 are attached by screws 26 or other suitable fixing means to suitable fixing points 28 (Fig. 2A) in the body interior, suitably formed as part of the extrusion 16. Front cover 18 closes the interior of the lamp body 12 and has cut-out apertures 30 to enable lamp holders 32 to be mounted at each longitudinal end of body unit 12. In use of the light fitting, the fluorescent light tube 34 is mounted parallel to the longitudinal axis of the body unit 2, located between the lamp holders 11. The louvre 14 is of substantially conventional design, dimensioned to suit the fluorescent tube (preferably a T5 type, 16 mm diameter tube) , and is further illustrated in Figs. 18A-C. The louvre comprises first and second parabolic side walls 36 disposed so that their convex surfaces face one another from opposite sides of the location occupied by the fluorescent tube 34. The side walls 36 are connected together by a plurality of planar cross-blades 38 extending substantially at right angles to the axis X-X' . The tube is received in the space between the upper edges of the side walls 36.

At each end of side walls 36, spigot holes 40 (or other suitable fixing means) are provided to enable the louvre 14 to be attached via spigots to a valance assembly, described further below (Figs. 3 to 8) . The valance assembly is attached to the lamp body 12, and the louvre 14 attaches to the valance assembly.

The sides 36 and cross-blades 38 are parabolic in shape and are made from materials with high luminous efficiency and low iridescence to conform to current legislative requirements, and to provide aesthetic appeal.

Suitable brackets can be used to attached the lamp apparatus to ceilings, walls, etc., and to orientate the fitting into any desired position, e.g. as a down- light, angled light, up-light etc. Suspension tubes 47a, 47b (Fig. 6c) can also be fitted to suspend the fitting from a ceiling and may have an orientation facility which allows the fittings to be angled from side to side. The fittings may also incorporate on/off pendant switches etc. A louvre blind attachment can be fitted to the bottom of the lighting unit below the main louvre to shape or shut off or shade the light source along its length, or over both halves of its length, and be able to control the angle of emitted light over the two lateral halves of the fitting.

According to this preferred embodiment, the main body unit 12 carries all of the electrical components of the light fitting such as lamp holders, electronic high frequency ballasts, terminal blocks, fuse holders and fuses, wiring and cable cleats and the like.

Fig. 2A shows a perspective view of the lamp body unit 12 with the end cap 24 removed. End cap 24 has apertures 42 for attaching the end cap to the gear tray 4 by means of the screws 26 or the like engaging the part-cylindrical formations 28 formed integrally with the side walls of the extruded gear tray 16. The extrusion 16, which is typically formed from aluminium, further includes groove-like corrugations 44 extending along the upper edges of its side walls parallel to the lamp body axis which engage with corresponding corrugations 46 formed on side walls of the lamp body cover 18. The lamp body cover 18 may also be formed as an extrusion, typically also of aluminium.

Fig. 2B shows the extruded lamp body cover 18, which comprises a front panel 48 and contiguous side walls 50 which extend parallel to the longitudinal axis X-X'of the light fitting. The extruded side walls 50 are shaped such that they form the groove-like corrugated engaging portions 46. The front panel 48 may be finished with a reflective surface, disposed in use behind the fluorescent tube 34. At each end of the lamp body cover 18, the lamp holder apertures 30 are formed for receiving the lamp holders 32.

Whilst it would be possible for the louvre 14 to be attached directly to the main body 12 in order to provide a functional light fitting, it is preferred that the light fitting includes a valance assembly to enclose the louvre 14 so as to provide improved aesthetic appearance.

Fig. 3A shows a valance body 52 suitable for attaching to the base unit 12, to which the louvre 14 is attached. Valance body 52 comprises side walls 54 which extend downwardly and outwardly, connected to one another at end portions 56, with an aperture 58 defined between the upper edges of the side walls 54.

Each end portion 56 includes lamp holder apertures 58, through which the lamp holders 32 project when the valance is fitted to the main body 12, and tabs 60 adapted to engage with valance end fittings (shown in Figs. 4A,4B and 4C) .

At each longitudinal end of valance side walls 54, spigots 62 (or other suitable fixing means) are provided, projecting into the space between the side walls 54, to engage with the louvre spigot holes 16 for attaching the louvre 14 to the valance body 52. Slots 64 (or other suitable fixing means) are provided at each end of the valance side walls 54 to enable decorative valance trim panels 66 (shown in Fig. 3B) to be attached by means of tabs 68 (or other suitable fixing means, e.g. lugs etc.).

Fig. 3B shows an alternative, preferred embodiment of the valance assembly in which the valance body 52 of Fig. 3A is replaced by first and second valance clips 70, corresponding generally to the end portions 56 of the valance body 52 of Fig. 3A. The side walls 54A and top surfaces of the clips 70 are similarly provided with lamp holder apertures 58A, end fitting tabs 60A, spigots 62A and slots 64A for attaching valence trim panels 66. Trim panels 66 may be further supported by longitudinal reinforcing strut (s) 72 extending between the clips 70 (only one strut 72 is shown for clarity; a second strut 72 would interconnect the other side walls 54A of the two clips 70) .

Figs. 4A, 4B and 4C show alternative end caps 74, 76, and 78 which can be attached to the valance assemblies and/or the main body 12 by any suitable means.

Fig. 5 is an exploded view of the standalone light- fitting 10 showing how the louvre 14 and valance assembly of Fig. 3B attach to the lamp body unit 12. Over each lamp-holder 32, there is located a valance clip 70 with trimslots 64A and lampholder apertures. The spigots 62A of the clips 70 engage the spigot holes 40 of the louvre 14 to secure the louvre 14 to the clips 70. The trim plates 66 are fitted to the outside surfaces of the clips 70 and latch into position by tabs or pins 68 engaging the slots 64A. At both ends of the fitting, an end cap 78 is fitted, which is then screwed to the lamp body 12. The bottom faces of the end caps 78 have removable access plates 80 to allow for louvre and lamp removal or replacement, without the need for having to strip down the fitting.

The trimplates 70 and end caps 78 can be removed and replaced, allowing the colour scheme of the lamp to be altered to suit changes in the surrounding decor, without the need to replace the entire light fitting. Figs. 6A, 6B and 6C show examples of stand-alone light fittings of the type illustrated by Figs. 1 to 5. Fig. 6C shows an embodiment in which suspension tubes 82 are attached to the base of the gear tray 16 to suspend the lighting apparatus 10 from a ceiling. Figs. 6A and 6B show similar stand-alone embodiments of the present invention, in which attachment points 84 suitable for fixing the light holder to the wall/ceiling are shown in the base of the gear tray 16.

Figs. 7A and 7B show transverse cross-sections of the lamp body 12, louvre 14 and valance in accordance with the preceding embodiments.

Figs. 8 to 12 illustrate embodiments of light fittings in accordance with the second aspect of the present invention. These embodiments provide a modular "track" -type lighting system in which individual lighting units and control units are connected together end to end for mounting along ceilings, down or across walls, along skirting runs and around doorways etc.

Advantageously, these embodiments employ box-section units formed from extrusions which can be substantially identical or similar to those employed in the main body units of the embodiments of Figs. 1 to 7.

Fig. 8 illustrates the basic arrangement of the modular track system, which consists of a plurality of lighting units 86 and a plurality of control units 88. In this case, the fluorescent tubes (lamps) are contained within the interior of the lighting units 86. Each control unit 88 controls two lighting units 86, one on either side of the control unit 88. A typical lighting track would thus comprise a first lighting unit 86, followed by a first control unit 88, followed by second and third lighting units 86, followed by a second control unit 88, followed by further lighting and control units to make up the required track length. The units 86, 88 incorporate first and second power buses extending along their lengths, a mains bus and a lamp supply bus . The mains bus carries the mains power supply to the control units 88, whilst the lamp supply bus carries power from the control units 88 to the lamps contained within the lighting units 86. Each unit has a mains bus plug and a lamp supply plug at one end thereof and a mains bus socket and a lamp supply socket at the opposite end, whereby the power supply connections between adjacent units may be established simply by plugging the plugs of one unit into the sockets of the adjacent unit. This arrangement allows a single supply cable to be used for a given number of lighting units in a given run or track of units (depending on loading and switching arrangements) , rather than having to run supply cables to individual units.

The units 86, 88 are each formed from a base or gear tray 216 and a cover 218, preferably formed from extruded aluminium and preferably identical in transverse cross section to those employed in the main body units 12 in the embodiments of Figs. 1 to 7. The covers 218 of the lighting units 86 differ from the covers 18 of the preceding embodiments in that they are provided with apertures in their external surfaces for receiving diffuser panels 90 (since the lamps are contained within the units rather than being mounted externally) . The ends of each unit 86, 88 are closed by end caps 224, again similar to the end caps 8 of preceding embodiments, but including apertures 92, 94 for the mains bus and lamp supply plugs and sockets. The system may further include corner units 96, 98 and 100 as shown in Figs. 9A, 9B, and 9C for connection in the sequence of lighting and control units 86, 88 where the lighting run is required to change direction. The different configurations of corner unit allow the track to be re-directed in any required direction; e.g. around doorways, between ceilings and walls etc. The corner units may be formed from mitred sections of extrusions the same as those of the principle units 86, 88, with similar end caps, plugs and sockets, but simply providing through connections for the mains bus and lamp supply.

Fig. 10 illustrates the mains bus plug and socket connection between two adjacent lighting units 86, one of the units having a mains bus socket 102 with socket holes 104 and the other having a mains bus plug 106 with plug pins 108. The lamp supply plug and socket may be similarly configured, but are omitted from the drawing for clarity.

Fig. 11 shows the internal arrangement of the gear tray 216 of the control unit 88. The gear tray 216 houses lamp ballast 110 and mains bus socket 102 and plug 106 and lamp supply socket 112 and plug 114. The electrical conductors (not shown) interconnect the plugs and sockets and the lamp ballast.

Fig. 12 shows the internal arrangement of a lamp body module 86. Lamp holders 232 are mounted within the interior of the gear tray extrusion 216, together with mains bus and lamp power plugs and sockets and electrical conductors as required. Fig. 12 also shows a joint cover member 116 which serves to cover the joints between adjacent units 86 and 88. The end of the cover plate 218 is shaped to provide a slot between the plate 218 and the end cap 224, into which a tongue 118 of the joint cover 116 may be inserted. Resilient portions 120 of the tongue 118 cooperate with the ends of the slot to secure the cover 116 in position. Aligning pins 122 may be inserted through apertures 242 in the end cap 224 and into part-cylindrical formations 228 on the side walls of the gear tray 216 to provide positive alignment of adjacent units 86/88 in an assembled lighting track.

The track system provided by this aspect of the invention can be used for room lighting, illuminated displays and signage, etc. It can be concealed behind fascias, plinths and pelmets. The diffusers can be transparent, translucent or prismatic, and of any required colour, and can carry wording or other indicia when used for illuminated signage. The units can be mounted directly to walls and ceilings or can be suspended or cantilevered as required. Different lengths of lighting unit can be incorporated into the same track sequence to suit the dimensions or geometry of the space in which the track is installed.

The use of extruded sections to form the main unit bodies in the embodiments of Figs. 1 to 7 and 8 to 12 is advantageous since the extrusions can simply be cut to length to suit different lengths of fluorescent tube (typically 575 mm, 875 mm, 1175 mm and 1475 mm) . In Figs. 8 to 12, the control units 88 might suitably be 375 mm in length to accommodate the longest ballast necessary for controlling two T5 lamps. The use of identical extruded sections for both systems is also advantageous in reducing the number of different stock items required for a variety of different lighting units and systems. Similar units could be produced having two fluorescent tubes extending side by side, by using a wider extruded section.

Fig. 13 illustrates a further aspect of the invention, in which an external casing or "duct" is provided for mounting stand-alone light fittings of the type illustrated in Figs. 1 to 7. The duct consists of two polygonal (in this preferred example, hexagonal) end caps 124 connected together at the required longitudinal spacing by a base plate or panel 126 which covers one of the sides of the polygonal caps. All but one of the remaining sides of the polygonal caps are also covered by removable panels 128. A light fitting 10 of the type previously described is mounted between the end caps 124, with the open face of the louvre 14 facing the open side of the duct. The light fitting 10 can be orientated to face any one of the sides of the end caps 124 other than that occupied by the base panel 126, with the remaining sides being covered by removable panels 128.

If the position of the base panel 126 is taken to be at 0°, then, for a hexagonal duct, the louvre 14 of the fitting 10 can be oriented to face either the 60° or 300° positions, to provide an "uplighting" effect, at the 120° or 240° positions to provide an angled "lightwash" effect, or at the 180° position to provide a "downlighting" effect.

The components of the duct can be formed from any suitable material, such as mild steel or aluminium, with panels formed in sizes to suit different lengths of light fitting. The finished fittings comprising the light fitting 10 and surrounding duct can be mounted on walls ceilings etc. individually, or multiple units may be butted against one another as shown in the drawing. The units can be mounted directly to supporting surfaces or may be suspended or cantilevered as required. The units may also be mounted on or beneath associated cable trunking which would carry the supply wiring.

In an alternative embodiment (not illustrated) , the polygonal end caps and planar base panel of Fig. 13 are replaced by circular end pieces interconnected by a part-cylindrical base section. An inner part- cylindrical section having a smaller diameter than the base section is mounted between the end pieces for rotational movement about its longitudinal axis relative to the base section. A lighting unit 10 is mounted in the inner section for rotation therewith. The inner section, including the light fitting, can be rotated relative to the base section to any required lighting angle and locked in position. The base section might suitably describe an arc of 60°, and the inner section an arc of 300°, leaving a 60° aperture with which the louvre 14 of the light fitting 10 is aligned. The part-cylindrical sections may be formed by extrusion, suitably of aluminium.

Figs. 14 to 17 illustrate a ceiling-mounted light fitting in accordance with a fourth aspect of the invention. Light fittings of this general type are known, providing accommodation for multiple fluorescent tubes and being designed to be mounted in standard apertures of modern suspended ceiling tee-bar grid systems. Existing units of this general type are designed for use with older types of fluorescent tube, such as 26 mm diameter "T8" type tubes. Such units have to fit standard size apertures (typically 600 x 600 mm, 600 x 1200 mm and 1200 x 1200 mm) . For this reason, difficulties are encountered in configuring units of this general type to accommodate 16 mm diameter T5 tubes in a manner which is technically and aesthetically acceptable.

Conventional units of this type comprise a base unit which is mounted in the ceiling aperture and which has mounted therein all of the electrical components of the fitting, including lamp holders and control gear. Louvres or other reflector assemblies or devices are fitted into the base unit. For T8 type lamps, louvres can be configured in such a way that they neatly fill the aperture area in a manner which is aesthetically acceptable. However, louvres suited to T5 tubes are smaller so that, for a T5 unit equivalent to an existing T8 unit, they do not fill the aperture space.

As seen in Fig. 14, a unit of this type in accordance with the invention comprises a base unit or body 130, a gear tray 132 and a louvre assembly 134. In the drawing, the unit is shown inverted; in use, the body 130 would be mounted in a ceiling aperture and the louvre assembly 134 would face downwards.

The body 130 may be similar or identical to the base units of existing light fittings of the same general type, in terms of size, format and hole configuration.

The gear tray 132 includes all of the electrical components of the fitting, including lamp holders, electronic HF ballasts, terminal block, fuse holder and fuse, wiring and cable cleats, and is mounted in the body 130. The body 130 includes a terminal block (not shown) for connection to external wiring in the suspended ceiling, and the gear tray 132 includes means for connecting the electrical circuitry thereof to the terminal block of the body 130. The louvre assembly comprises main louvres 314, similar or identical to the louvres 14 of the embodiments of Figs. 1 to 7 and illustrated in Fig. 18, and a secondary louvre grid 136. The main louvres 314 are located in apertures 138 formed in the secondary louvre grid 136. Fig. 14 shows one of the main louvres 314A mounted in its correct position in aperture 138. A second main louvre 314B is shown inverted, for the purpose of illustrating its location in the aperture 138 (i.e. it shows how the main louvre 314A would appear if viewed from the opposite side of the secondary louvre grid. The main louvre is omitted from the central aperture 138 for the purpose of illustrating the aperture itself.

The main louvres 314 thus occupy a certain proportion of the total area of the unit, with the remaining area being covered by the secondary louvre grid 136.

Louvre grids of this type are known, comprising an array of grid cells which may be of any of a variety of shapes and configurations. Conventionally, a light fitting of this general type would employ either a plurality of main louvres similar to (but larger than) the present main louvres 314, which abut one another and together occupy the entire area of the fitting, OR a continuous louvre grid covering the entire area of the fitting. The present invention combines these two known types of louvres in a manner not hitherto known, so as to provide a functional and aesthetically pleasing solution particularly suited to T5 type fluorescent tubes.

Fig. 14 shows a unit configured to accommodate three fluorescent tubes. Fig. 15 shows another embodiment having four tubes and hence four main louvres 314. The units are particularly intended to be fully recessed into a suspended ceiling, but could be semi-recessed or surface mounted. In this case, the unit may be fitted with trim panels 140 fitted around the sides of the unit to improve its aesthetic appearance. Fig. 15 shows the unit assembled and facing downwards in its correct orientation.

Fig. 16 shows the secondary louvre grid of the unit of Fig. 15, with four main louvre apertures 138. Fig. 17 shows an alternative embodiment of the secondary louvre grid, having a single large aperture dimensioned to accommodate a plurality of main louvres 314 side by side in abutment with one another.

The gear tray 132 is also suited for mounting in a previously installed body 130 of an existing, conventional light fitting, by removing the obsolete components and wiring of the old unit and securing the gear tray within the existing unit. Alternatively, a complete new unit comprising the body 130, gear tray 132 and louvre assembly 134 can be provided.

The secondary louvre grid may be formed by forming suitable apertures in any one of a variety of existing types of louvre grid material, which may be plastic or metal, and can be square, unequal, round, hexagonal, or asymmetric in pattern. The grid cells may be straight sided or parabolic sided. The grid can have a highly reflective specular or semi-specular metallised finish, or can be finished in any required colour. White or coloured plastic diffusers can be fitted to the grid as an optional addition.

The embodiments of Figs. 14 to 17 are suited for converting existing light fittings (such as T8 fittings) for use with different types of fluorescent tube (such as T5 tubes) , but require both the gear tray and louvre assembly (including parabolic reflectors for each tube) to be replaced. The following embodiments illustrated in Figs. 19 to 21 enable an existing fitting (such as T8) to be adapted for use with smaller diameter tubes (such as T5) , by replacing only the gear tray whilst still employing the original louvre assembly, including the original parabolic reflectors.

If standard tube-holders and tubes of a first diameter in an existing light fitting are simply replaced by standard tube holders and tubes of a smaller diameter, then the new, smaller tubes will not be located at the focal point of the existing parabolic reflectors, so that the lighting performance of the fitting will be impaired.

Fig 19 illustrates an embodiment of the invention in which a body 130 of an existing lighting unit such as, for example, may have been originally designed for T8 technology, has been adapted to utilise T5 technology.

As shown in Fig. 19, a replacement gear tray 132 is provided with height adjusting means, for example inserts 350, which adjust the height of the T5 light tubes relative to the position of the gear tray. Each insert 350 provides support for lamp holders 332 provided at each end of the T5 light tube 34.

The height 'X' by which the insert 350 extends above the outer surface of the gear tray 132 (see Fig. 20B) is selected to optimise the position of the T5 light tube 34; i.e. so that the tubes 34 are located substantially at the focal points of the parabolic reflectors of the existing louvre assembly (not shown) when the louvre assembly is fitted to the body 130.

If the new T5 lamp tubes are not correctly positioned in the original body 130, the output of the T5 lamps may be unduly decreased and/or the amount of glare from the lamps increased. Adapting an existing light fitting for T5 technology involves raising the narrower diameter T5 tubes into a position in which the longitudinal axis (X-X' in Fig. 1) of the T5 light tube is substantially in the same position occupied by the longitudinal axis of the original, wider lamp tube. This involves raising the lamp holders 332 using inserts 350 by a height 'X', illustrated in Fig. 20B.

As seen in Figs. 20A and 20B, suitable apertures 351 are provided upon the inserts 350 to receive the lamp holders 332.

It will be understood that a variety of different spacing and/or packing means may be employed to adjust the position of the tubes relative to the body 130 so as to be properly aligned with the louvre assembly. This may include adjusting the position of the gear tray 132 relative to the body 130 in addition to adjusting the position of the tubes 34 relative to the gear tray 132. The necessary height adjustment will depend on the configuration of the existing lighting unit.

Fig 21 shows an alternative embodiment of a gear tray 150 providing height adjusting means for T5 lamp tubes. The gear tray 150 has a substantially corrugated structure and comprises a series of raised portions 151 and base portions 152. The raised portions 151 provide support for T5 lamp holders (not shown) such that they can be correctly positioned within an existing lamp fitting. The raised portions 151 include apertures 153 for receiving the lamp holders (not shown) in a similar manner to the embodiment of Figs. 19 and 20.

As in the embodiments of Figs. 14 to 17, the body unit 130 may be recessed into a ceiling, mounted directly to the ceiling or suspended from the ceiling. Decorative trim panels may be attached to the sides of the unit as before, if required.

Figs. 22 to 25 illustrate additional examples of lighting units which incorporate basic lighting units of the type previously described with reference to Figs . 1 and 2.

Figs 22A and 22C show two ceiling mounted embodiments 400a, c of such lighting units, of differing lengths, and Figs 22B and 22D show two similar suspended lighting units 400b, d. Figs. 23A, 23B, and 24A show further views of these units. Fig 23C is a view of a similar lighting unit 400e suitable for use in a restricted ceiling position, for example, adjacent to a wall, or for wall mounting. Fig. 25 is a sectional end view illustrating the construction of these units.

As seen in Fig. 25, the units include first and second basic units 403 of the type shown in Fig. 1. The basic units 403 may be enclosed by suitable casings and/or trim panels or the like in a variety of configurations. In this example, the enclosure for the basic units 403 includes suitable end panels 410 (Fig. 24B) .

As seen in Fig. 25, these embodiments include the main lighting tubes 401a and associated louvres 404 of the basic units 403, with additional side tubes 401b and associated side reflectors 405 mounted on the sides of the basic units 403. Each tube 401a, b is supported by lampholders 402.

The louvres 404 of the basic units 403 provide direct downlighting, whilst side reflectors 405 provide additional indirect downlighting. The embodiment of Fig. 23C simply comprises one half of the units of the other, similar embodiments; i.e. one basic unit 403 and one side tube 401b and side reflector 405.

These embodiments demonstrate the versatility of the basic lighting unit of Fig. 1 in providing the basis for a range of lighting units of varying shapes, sizes and configurations.

Fig. 26 illustrates embodiments of lighting units adapted for use with circular fluorescent tubes 501, again preferably of T5 type and which, in common with embodiments of Figs. 14 to 17, again may allow the conversion of existing T8 units or the like for use with different types of tube. These embodiments again include a main body unit 505 and insert 500a, b including a gear tray 502. Each circular lamp tube 501 is supported by a support 503 and by a lamp holder 504. The lamp tubes 501 may be raised to a suitable height relative to the gear tray 502 by the lamp holders 504 and supports 503 so that a suitable configuration can be arranged within an existing body 505 and/or to increase the light output. Alternatively, the position of the gear tray 502 can be adjusted relative to the body 505 so that the lamps are positioned optimally for light output/glare reduction.

The gear tray 502 replaces the existing gear tray and provides all necessary control gear to suit the circular lamps. Various materials can be adapted to provide reflectors, louvres and diffusers for circular lamps 501. For example, a mirror tile 506 can be provided with suitably positioned apertures 507 to provide a main diffuser. Conventional louvre hexcell grids may be provided between the diffuser 506 and the lamp tubes 501 within the light fitting. An annular specular reflector 508 may provided to surround each lamp and attached to the gear tray 502 or diffuser 506 by suitable fixing means, for example clips. A circular frill assembly 509 may be attached to the annular reflector 508 or diffuser 506; e.g. by means of latches 510 which engage with slots 511 on the circular reflector 508.

Wiring and control of a plurality of lighting units in accordance with the various aspects of the invention may be facilitated by the use of suitable marshalling or distribution boxes as illustrated in Figs. 27 and 28.

Figs. 27A to 27D illustrate first embodiments of a distribution box, comprising a generally rectangular casing 600 and lid 601. A plurality of apertures 602 are provided for receiving a plurality of output plugs 614 (Fig. 27B) , by which wiring may be connected between the box and a number of lighting units by means of simple plug and socket connections. Input wiring may be connected to the box at 603, again by a plug/socket connection, from which power is distributed to the various output sockets.

The box may enclose substantially conventional electrical/electronic power distribution, switching and control gear. Fig 27C is an internal plan view of one example of a distribution box 611. In this example, power from the input 603 is simply distributed to the various outputs 614. Fig. 27D is an internal plan view of an alternative distribution box 612 which is similar to that of Fig. 27C but further includes electronic control means 613 for controlling the power supply to the outputs 614, which may provide on/off and or dimming functions and may provide remote control (e.g. infra red remote control) by means of a remote handset or the like.

One or more lighting units may be connected to each output plug 614 of the boxes 611, 612.

Figs. 28A to 28D show another embodiment of a distribution box 601 according to the invention.

In this case, there are multiple input connections 711, 712, 713 and 714 and the outputs 614 are connected together in groups of two or three associated with each of the inputs. This allows groups of lighting units to be controlled independently of one another. It will be understood that this is merely an example and that different numbers and groupings of inputs and outputs could be employed. This unit may also incorporate electronic/remote control as in the previous example. It can be seen that a complex lighting installation may be wired up in any of a variety of configurations to provide a variety of switching and control arrangements .

The inputs are connected to the outputs via fused terminal blocks 721,722,723,724. The wiring can include emergency lighting circuitry and controls as well as dimmable lighting and remote control circuitry. Fig. 28B illustrates a four pole socket 715 for use at the inputs 711,712,713,714, complementing the plugs 614 as shown in Figs. 27B and 28D.

Fig. 28D illustrates an alternative arrangement of input and output apertures 750 and 751.

The invention thus provides a variety of types of light fittings and systems which are particularly suited to T5 fluorescent lighting technology but which may also be adapted for use with other types of fluorescent lights. The invention further provides convenient and cost effective means for converting existing lighting installations (e.g. T8 type installations) for use with improved lighting technology (e.g. T5 technology).

Modifications and improvements may be incorporated without departing from the scope and spirit of the invention.

Claims

1. A light fitting for at least one fluorescent tube lamp comprising an elongate, box-section main body unit consisting of: a base member, a cover member, end cap members and lamp holders spaced along the length of the main body for receiving a fluorescent tube therebetween.

2. A light fitting as claimed in Claim 1, wherein the base member and the cover member comprise extruded members of uniform transverse cross-section.

3. A light fitting as claimed in either Claim 1 or Claim 2, wherein the lamp holders are located on an external surface of said cover member so that the lamp is mounted externally of the main body unit; and further comprising control gear for the lamp located within the body unit, wherein the light fitting further includes a reflector assembly extending along the length of the cover member.

4. A light fitting as claimed in Claim, further including a valance assembly secured to the cover member and having removable trim panels which extend along the length of the light fitting externally of said reflector assembly.

5. A light fitting as claimed in Claim 4, wherein the valance assembly further includes end cap members adapted to cover the ends of the main body unit and of the reflector assembly.

6. A light fitting as claimed in any one of Claims 3 to 5, further including lamp holders spaced along one side of said base member for receiving a further fluorescent tube therebetween.

7. A light fitting as claimed in either of Claims 1 or 2 , wherein the lamp holders are enclosed within the base member and the cover member includes an aperture fitted with a light diffusing member.

8. A modular lighting system comprising: lighting units, each for at least one fluorescent tube lamp, the lighting units comprising an elongate, box-section main body unit consisting of a base member, a cover member including an aperture fitted with a light diffusing member, end cap members and lamp holders contained within and spaced along the length of the main body for receiving a fluorescent tube therebetween; control units, each comprising an elongate, box- section main body unit consisting of a base member, a cover member and end cap members, and lighting control gear contained within the main body for controlling operation of the lighting units, said control units having a similar cross-sectional configuration to said lighting units; said lighting and control units being adapted to be connected together end to end to form a lighting track.

9. A modular lighting system as claimed in Claim 7, wherein said lighting and control units each include plug means at one end thereof and socket means at the other end thereof, and electrical bus means connecting said plug and socket means, whereby adjacent units may be connected together by inter-engagement of their respective plug and socket means and whereby electrical power may be distributed amongst the connected units.

10. A modular lighting system as claimed in Claim 9, wherein said bus means includes a first mains supply bus having a first plug and a first socket associated therewith, and a lamp supply having a second plug and a second socket associated therewith.

11. A modular lighting system as claimed in any one of Claims 8 to 10, wherein each control unit is adapted to control the operation of first and second lighting units, one of said lighting units being connected to each end of the control unit.

12. A modular lighting system as claimed in any of Claims 8 to 11, wherein the system further includes corner units comprising angled, box-section main body units consisting of a base member, a cover member and end cap members, and including plug and socket means at either end thereof and electrical bus means connecting said plug and socket means, said corner units having a similar cross-sectional configuration to said lighting and control units.

13. A modular lighting system as claimed in any one of Claims 8 to 12, wherein the base members and cover members of the various units comprise extruded members of uniform transverse cross-section.

14. A modular lighting system as claimed in Claim 13, wherein the extrusions are substantially identical to those employed in the light fittings as claimed in Claim 2.

15. A lighting duct apparatus comprising a pair of end pieces spaced apart and adapted to support an elongate light fitting therebetween such that the light fitting may be rotated about its longitudinal axis to any required orientation relative to the end pieces, and duct panels connected to the end pieces to enclose the light fitting.

16. A lighting duct apparatus as claimed in Claim 15, wherein the end pieces are connected together by a first duct panel portion, the remainder of the duct being formed from further panel portions.

17. A lighting duct apparatus as claimed in either Claim 15 or Claim 16, wherein the end pieces are polygonal and the duct panels are generally planar and are connected to respective sides of the end piece.

18. A lighting duct apparatus as claimed in either Claim 15 or Claim 16, wherein the end pieces are circular and are interconnected by an arcuate section base portion, the remainder of the duct being formed from a further arcuate section portion which is rotatable between the end pieces, the further arcuate section being adapted to receive the elongate light fitting therein.

19. A lighting duct apparatus as claimed in any one of Claims 15 to 18 wherein the elongate light fitting comprises a light fitting as claimed in any one of Claims 1 to 6.

20. A light fitting comprising a body adapted to be mounted to or recessed in a ceiling, a gear tray including a plurality of lamp holders and associated electrical components adapted to be mounted within the body, and a louvre assembly comprising at least one main louvre located in at least one aperture formed in a secondary louvre grid, whereby said at least one main louvre occupies a proportion of the surface area of the light fitting and the remaining surface area is covered by said secondary louvre grid.

21. A kit of parts for use in converting an existing light fitting of the type comprising: a body adapted to be mounted to or recessed in a ceiling; a gear tray adapted to be mounted within the body and including a plurality of lamp holders for holding fluorescent tubes of a first type having a first diameter and associated electrical components, and louvre means associated with said lamp holders; said kit of parts including: a replacement gear tray adapted to be mounted within the body and including a plurality of lamp holders for holding fluorescent tubes of a second type having a second diameter less than said first diameter and associated electrical components.

22. A kit of parts as claimed in Claim 21, further including a louvre assembly for replacing said louvre means, said louvre assembly comprising at least one main louvre located in at least one aperture formed in a secondary louvre grid, whereby said at least one main louvre occupies a proportion of the surface area of the light fitting with which the kit is intended to be used and the remaining surface area is covered by said secondary louvre grid.

23. A kit of parts as claimed in Claim 21, wherein said replacement gear tray is adapted for supporting said lampholders in such a manner that, in use, said fluorescent tubes of said second type are located in substantially the same position relative to said louvre means as said fluorescent tubes of said first type. 5063

37 24. A kit of parts as claimed in Claim 21, wherein said replacement gear tray and lampholders are adapted for use with circular fluorescent tubes and further including diffuser means adapted for use with said circular fluorescent tubes.

25. A lighting system comprising a plurality of light fittings as claimed in any preceding Claim and including at least one distribution box for use in distributing power between said plurality of light fittings, said distribution box having at least one power supply input and a plurality of outputs connected to said at least one input.

26. A lighting system as claimed in Claim 25, wherein said inputs and outputs of said distribution box comprise plug/socket connectors.

27. A lighting system as claimed in Claim 25 or Claim 26, wherein said distribution box includes electronic control means for switching and/or dimming light fittings connected to said outputs.

28. A lighting system as claimed in Claim 27, wherein said electronic control means is adapted to be remotely controllable.