LUMINAIRE HOUSING AND LUMINAIRE

The present invention relates to luminaires or light fittings (hereinafter, 'luminaire') and in particular luminaire housings for holding a light source or light engine (hereinafter, 'light source') in a recess, cavity or aperture. Example applications include down lights, spot lights, wall lights, and lights installed in ceilings and ground cavities.

Conventional luminaire housings are rigid structures constructed from ferrous metallic material, such as steel, with a powdered coating, or from stainless steel. Fasteners, such as tensioned spring clips or circlips, are provided both to hold the housing in place in a recess and to hold a light source in place in the housing.

There are a number of technical problems with conventional luminaire housings.

Firstly, they are heavy, expensive to produce, and corrosive. They are not suitable for moist environments, such as bathrooms or outdoors, and provide little resistance against water vapour.

Secondly, conventional luminaires are generally only designed for use with incandescent or halogen light sources, which require a high operating temperature, and do not provide for the effective transfer of heat energy from the light source to the luminaire housing and ultimately to the surrounding environment. Such constructions are unsuitable for new high-efficiency light sources such as light emitting diodes (LED), laser and fibre optic, which require the high transfer of heat energy in order to increase their longevity (if the temperature of a LED is increased by twofold, its life expectancy is halved). Moreover, incandescent light sources have been banned in most developed countries, and halogen light sources are likely to go in the same direction.

Thirdly, the fasteners of conventional luminaires are cumbersome and difficult to use making installation, removal and maintenance time consuming and complex. They also have the tendency to get damaged and can often fall out. During maintenance force is required to remove the conventional housing from its recess due to tension within the fasteners that hold the housing, and this can lead to damage to the installed finish. The life of the light source is often very short and this tends to cause repeated damage to the installed surface, often negatively impacting the fire integrity of the ceiling.

Fourthly, most conventional luminaires only have live and neutral electrical connections. This problem is aggravated by the fact that the body of most existing luminaires are conductive, thus making it dangerous and unsafe for users. In fact, new electrical regulations now recommend an earth terminal for safety.

It is an object of the present invention to obviate or mitigate the above problems of luminaires being heavy, expensive, corrosive and unsuitable for light sources which require a high transfer of heat energy. It is a further object of the present invention to obviate or mitigate the above problems associated with using fasteners to install luminaire housings within recesses and light sources within luminaires. It is a further object of the present invention to obviate or mitigate safety and energy efficiency problems of conventional luminaires.

Accordingly, the present invention provides a luminaire housing defining a cavity adapted to receive and hold a light source in place, the luminaire housing comprising a composite of an elastomeric material and a conductive material.

Advantageously, the elastomeric material provides the luminaire housing with a wide serviceable temperature range; resistance to oxidization, ozone, and UV radiation; non- adhesive properties; low toxicity; and electrically insulative properties. Moreover, the elastomeric material enables the luminaire housing to have low chemical reactivity; be flame retardant; and be easy to manufacture and manipulate. Meanwhile, the conductive material allows the luminaire housing to act as a heat sink to transfer thermal energy away from the light source, thus making the luminaire housing ideally suited for light sources such as LED, laser or fibre optic which require the high transfer of heat energy through conduction, convection and radiation in order to increase their longevity.

The proportion of the elastomeric material to the conductive material is adjustable, and can be chosen based on the desired properties and application of the luminaire housing.

Preferably, the conductive material comprises up to 1 % of the composite. Ideally, the conductive material comprises up to 10% of the composite. Preferably, the conductive material comprises up to 20% of the composite.

Ideally, the conductive material comprises up to 30% of the composite.

Preferably, the conductive material comprises up to 40% of the composite.

Ideally, the conductive material comprises up to 50% of the composite.

Preferably, the conductive material comprises up to 60% of the composite.

Ideally, the conductive material comprises up to 70% of the composite.

Preferably, the conductive material comprises up to 80% of the composite.

Ideally, the conductive material comprises up to 90% of the composite.

Preferably, the conductive material comprises up to 99% of the composite.

Ideally, the conductive material comprises or consists of a metal alloy.

Preferably, the conductive material comprises or consists of a non-ferrous metal alloy.

Alternatively, the conductive material comprises or consists of a semiconducting material.

Preferably, the semiconducting material comprises or consists of graphene, silicon or germanium or a combination thereof.

Advantageously, dopants can be introduced into portions of the semiconducting material to enhance either the insulative or conductive properties of the semiconducting material.

Advantageously still, graphene offers mechanical properties that are 200 times stronger compared to traditional steel, and thus enhances the mechanical strength of the luminaire housing whilst reducing weight.

Advantageously still, the non-ferrous metal alloy or semiconducting material is resistant to oxidation and therefore suitable for use in a bathroom or outdoor environment.

Ideally, the elastomeric material is flexible.

Ideally, the flexible elastomeric material comprises or consists of inorganic elastomeric silicone. Preferably, the inorganic elastomeric silicone has between Shore 40 and Shore 60.

Ideally, the inorganic elastomeric silicone has Shore 60.

Preferably, the elastomeric material is optically transparent.

Ideally, the luminaire housing weighs between 25 grams and 100 grams.

Preferably, the luminaire housing weights between 40 grams and 70 grams.

Advantageously, the flexible elastomeric material is cheap, lightweight and corrosion resistant in comparison to the steel and stainless steel used in conventional luminaires.

Ideally, a portion of the outer surface of the luminaire housing is coated with an insulative material. Advantageously, this enables the insulative properties of part of the outer surface of the luminaire housing to be enhanced.

Preferably, the luminaire housing is adapted to be received and installed in a recess.

Ideally, the recess is formed for receiving the housing.

Ideally, the luminaire housing comprises a retaining means.

Preferably, the retaining means being adapted to extend into the recess.

Ideally, the retaining means being adapted to retain and hold the luminaire housing in place in the recess without the use of clips or fasteners.

Preferably, the retaining means is flexible and resilient.

Ideally, the retaining means is permanently formed on the luminaire housing. By permanently formed we mean that the material of the retaining means is homogeneous with the material of the luminaire housing.

In an alternative arrangement, the retaining means is separate from the luminaire housing and configured to be releasably or fixedly positioned over part of the outer surface of the luminaire housing. In this alternative arrangement, the retaining means can be

constructed from a different material to that of the luminaire housing.

Ideally, at least part of the retaining means forms an interference fit with the recess.

Preferably, at least part of the retaining means defines at least one diameter which is larger than the largest diameter of the recess in which the luminaire housing is to be inserted. Advantageously, the flexible/resilient properties of the retaining means allows it to deform to an installation configuration having a diameter smaller than the largest diameter of the recess when pushed into the recess. Furthermore, the flexible/resilient properties of the retaining means allows it to expand, once positioned within the recess, to an in -use retention configuration where the retaining means positively engages with at least part of the surface forming the recess to retain the luminaire housing in place within the recess.

Ideally, the retaining means is sized to positively engage with ceiling thickness of 2mm to 30mm.

Preferably, the retaining means is sized to positively engage with typical ceiling thicknesses of 10mm, 13mm and 27mm.

Preferably, the luminaire housing comprises a plug, the plug having at least one deformable protrusion protruding from the external surface of the plug, the at least one protrusion providing the retaining means.

Ideally, the at least one protrusion protrudes for a radial distance in the range of 3mm to 8mm from the external surface of the plug.

Preferably, the at least one protrusion has a pitch in the range of 3mm to 8mm.

Ideally, the at least one protrusion is cut into a side wall of the plug.

Ideally, the plug being generally tubular and having a longitudinal axis, the at least one protrusion comprises a plurality of discrete continuous or discontinuous protrusions spaced apart along the longitudinal axis of the external surface of the plug.

Ideally, the discrete continuous or discontinuous protrusions are ridges.

Preferably, the pitch between the ridges is constant around the circumference.

Ideally, the discrete continuous or discontinuous protrusions vary from a coarse discrete continuous or discontinuous ridge close to the upper-most end of the plug to a fine discrete continuous or discontinuous ridge close to a lower-most end of the plug.

Preferably, the plug is generally tubular having a constant cross-section along the length of the tube. In this arrangement, the plug has a substantially rectangular or circular cross-section. In an alternative arrangement, the plug is a truncated tubular cone.

Preferably, the truncated tubular cone is an oblique truncated tubular cone.

Ideally, the truncated tubular cone is a conical tubular frustum.

In this alternative arrangement, the upper-most end of the plug is smaller and therefore easier to push into an inlet/opening of the recess. As the luminaire housing is pushed into the recess, the width of the plug progressively increases, ensuring that the retaining force generated by the plug is sufficiently large to prevent the luminaire housing from falling out of the recess.

In another alternative arrangement, the plug is a truncated tubular cylinder or an oblique truncated tubular cylinder.

Preferably, the plug further comprises a seal means. Preferably, the seal means is a ring or O-ring. Advantageously, the ring or O-ring improves the sealing properties of the luminaire housing.

Ideally, the ring or O-ring has a diameter of 30mm to 200mm.

Preferably, the ring or O-ring has a diameter of 30mm to 100mm.

Ideally, the ring or O-ring has a diameter of 50mm to 60mm.

Ideally, the ring or O-ring has a diameter of 58mm.

Advantageously, the retaining means enables the luminaire housing to be held in the recess without fasteners or clips, which are difficult and cumbersome to use. Importantly, the luminaire housing is easy to install, remove and does not cause damage to the face of the recess in which it is installed. The recesses are generally formed in plasterboard which is liable to crushing under duress. Furthermore, the retaining means forms a tight seal in the recess, with a high ingress protection (IP) rating of up to 100%, whilst having a minimal risk of falling out of the recess under the force of gravity or an external impact.

Ideally, the luminaire housing further comprises a light-source retaining means.

Preferably, the light source retaining means being adapted to extend inwardly from the internal surface of the luminaire housing. Ideally, the light source retaining means being adapted to hold the light source in the cavity without the use of clips or fasteners.

Preferably, the light source retaining means is a lip/shoulder extending inwardly from the internal surface of the luminaire housing and into the cavity, the lip/shoulder being adapted to engage with the light source when the light source is positioned within the cavity and hold the light source in place.

Ideally, the luminaire housing being adapted to be installed in a recess formed for receiving the housing, the luminaire housing comprising a plug having retaining means for retaining the plug in the recess, and light source retaining means having a lip/shoulder adapted to extend inwardly from the internal surface of the plug and into the cavity.

Preferably, the lip/shoulder being adapted to extend inwardly from the internal surface of the plug at a position proximal to a lower-most end of the plug.

Ideally, the light source retaining means is flexible and resilient

Preferably, the light source retaining means is permanently formed on the luminaire housing. By permanently formed we mean that the material of the light source retaining means is homogeneous with the material of the luminaire housing.

In an alternative arrangement, the light-source retaining means is separate from the luminaire housing and configured to be releasably or fixedly positioned over part of the inner surface of the luminaire housing.

In this alternative arrangement, the light-source retaining means can be constructed from a different material to that of the luminaire housing.

Ideally, the lip/shoulder comprises a ribbed ring.

Preferably, the ribbed ring has an undercut with an expandable edge for positive and non-positive accommodation of the light source.

Advantageously, the light source retaining means allows for light sources to be installed and retained within the luminaire housing without the use of clips or fasteners. This makes installation, removal, and maintenance less labour intensive, and reduces the risk of damage to the housing/light source. Ideally, the light source retaining means has a first normal position protruding into the cavity so as to retain a light source in the cavity and a second deformed configuration allowing a light source to pass into and out of the cavity.

Advantageously, the flexible and resilient properties of the light source retaining means allows it to deform when a light source is pushed into the cavity, and then expand outwards to engage with the light source and hold it in place.

Ideally, the luminaire housing comprises a bezel.

Preferably, the luminaire housing being adapted to be received and installed in a recess, the bezel adapted to be flush with or extend out of an inlet/opening of the recess.

Ideally, the luminaire housing being adapted to be received and installed in a recess, the luminaire housing comprising a plug having retaining means, the plug adapted to extend into the recess, the bezel adapted to be extend from a lower-most end of the plug and be flush with or extend out of an inlet/opening of the recess.

Preferably, the bezel is integral with the luminaire housing.

In an alternative arrangement, the bezel is releasably connectable with the luminaire housing.

Preferably, a back face of the bezel is implanted with additives adapted to change the colour of a front face of the bezel.

Ideally, the bezel comprises a secondary light source.

Preferably, the secondary light source is adapted to change the colour of a front face of the bezel.

Ideally, the secondary light source is driven by a polymer battery installed in a back face of the bezel.

Preferably, the secondary light source is adapted to glow uniformly throughout the bezel's width.

Ideally, the secondary light source is adapted to be controlled using secondary light controlling means. Preferably, the secondary light controlling means uses Infrared or Radio Frequency technology.

Ideally, the secondary light source comprises at least one Red-Green-Blue (RGB)

LED.

Advantageously, the secondary light source can be used to provide 'mood' lighting, whereby the colour of the bezel is changed to match the user's mood or to create a certain ambience.

Alternatively, the bezel can be covered with a cover plate.

Ideally, the cover plate is configured to be clipped onto the bezel.

Preferably, the cover plate is implanted with additives adapted to change the colour of a front face of the cover plate.

Ideally, the cover plate comprises a secondary light source.

Preferably, the secondary light source is adapted to change the colour of a front face of the bezel.

Ideally, the secondary light source is driven by a polymer battery installed in a back face of the cover plate.

Preferably, the secondary light source is adapted to glow uniformly throughout the cover plate's width.

Ideally, the secondary light source is adapted to be controlled using secondary light controlling means.

Preferably, the secondary light controlling means comprises Infrared or Radio

Frequency technology.

Preferably, the secondary light source comprises at least one Red-Green-Blue (RGB)

LED.

Preferably, the luminaire housing comprises a ventilating hood/cap.

Ideally, the luminaire housing being adapted to be received and installed in a recess, the ventilating hood/cap adapted to extend into the recess. Preferably, the luminaire housing being adapted to be received and installed in a recess, the luminaire housing comprising a bezel, the ventilating hood/cap adapted to extend into the recess, the bezel adapted to be flush with or extend out of the recess.

Ideally, the luminaire housing being adapted to be received and installed in a recess, the luminaire housing comprising a plug having retaining means, the plug adapted to extend into the recess, the plug having an upper-most end and a lower-most end, the lower-most end adapted to be proximal to an inlet/opening of the recess, the ventilating hood/cap bei ng adapted to extend from the upper-most end of the plug and into the recess.

Preferably, the luminaire housing being adapted to be received and installed in a recess, the luminaire housing comprising a plug having retaining means, the plug adapted to extend into the recess, the plug having an upper-most end and a lower-most end, the lowermost end adapted to be proximal to an inlet/opening of the recess, the luminaire housing further comprising a bezel, the bezel adapted to extend from the lower-most end of the plug and be flush with or extend out of the inlet/opening of the recess, the ventilating hood/cap adapted to extend from the upper-most end of the plug and into the recess.

Preferably, the ventilating hood/cap is a tapered tubular body.

Preferably, the tapered tubular body is of substantially frustoconical shape.

Preferably, the ventilating hood/cap comprises at least one vent hole.

Ideally, the ventilating hood/cap comprises a plurality of vent holes.

Preferably, the plurality of vent holes are arranged in vertical rows spaced equidistantly apart around the surface of the ventilating hood/cap.

Ideally, each vertical row comprises at least 3 vent holes, and there are at least 8 vertical rows of vent holes in total.

Ideally, at least one of the vent holes is positioned such that an air gap is provided between the at least one vent hole and the light source when the light source is positioned within the luminaire housing.

Preferably, at least one of the vent holes is positioned such that it directly contacts with the light source when the light source is positioned within the luminaire housing. Advantageously, the vent holes provide a route for heat dissipation. The at least one vent hole with an air gap provided between the light source provides a route for heat dissipation from the light source by convection. Meanwhile, the at least one vent hole positioned in direct contact with the light source provides a route for heat dissipation from the light source by conduction and radiation.

Ideally, portions of the luminaire housing at or about the at least one vent hole comprise added conductive material.

Preferably, the longitudinal axis of the ventilating hood/cap is positioned at an angle with respect to the plug to form a partly slanted luminaire housing.

Ideally, the angle is 15-45 degrees.

Preferably, the angle is 25-35 degrees.

Most preferably, the angle is 30 degrees.

Preferably, the luminaire housing comprises a cooling heat sink.

Ideally, the heat sink is a Peltier thermostatic heat sink.

Ideally, the partly slanted luminaire housing is sized to have a large surface area for transfer of heat energy from the light source to the surrounding environment.

Advantageously, the partly slanted luminaire housing retains the light source at an angle, thereby providing angled light which is particularly suited for shop accent lighting.

Preferably, the luminaire housing further comprises additives added to enhance the fire retardant properties of the luminaire housing.

Ideally, the luminaire housing can withstand temperatures from -100°C to 800°C.

Preferably, the cavity is shaped to reflect light using total internal reflection.

Ideally, a mirror-like film is provided on the inner surface of the luminaire housing defining the cavity. Advantageously, the mirror-like film improves the reflection of light.

Accordingly, the present invention further provides a luminaire housing defining a cavity adapted to receive and hold a light source in place, the luminaire housing comprising a conductive material, the cavity shaped to reflect light using total internal reflection.

Ideally, the luminaire housing is constructed from graphene. Accordingly, the present invention further provides a luminaire housing defining a cavity adapted to receive and hold a light source in place, the luminaire housing comprising a plug having retaining means, the plug being a truncated tubular cone or cylinder.

Ideally, the truncated tubular cone being a conical tubular frustum.

Preferably, the retaining means being adapted to retain and hold the luminaire housing in place in a recess.

Accordingly, the present invention further provides a luminaire comprising : a luminaire housing defining a cavity adapted to receive and hold a light source in place, the luminaire housing comprising a composite of an elastomeric material and a conductive material; and a light source.

Ideally, the light source is a halogen light source.

Preferably, the light source is a LED light source.

Ideally, the light source is a fibre-optic light source.

Preferably, the light source is a laser light source.

Ideally, the light source is operated under either DCV or ACV mains driverless supply power sources.

Preferably, the light source is a fibre optic, laser light source, or a LED light source and is adapted to be operated using mains ACV rated at 100 to 270VAC.

Preferably, the light source is mounted on a semiconducting substrate.

Ideally, the semiconducting substrate comprises or consists of graphene, silicon or germanium or a combination thereof.

Ideally, the light source comprises a semiconducting lens.

Preferably, the semiconducting lens comprises or consists of graphene, silicon or germanium or a combination thereof. Advantageously, the graphene lens increases transmission of light capture and allows up to 98% transmission of light.

Preferably, the light source is mounted on a rotatable joint.

Preferably, the joint provides up to 180 degrees of rotation.

Ideally, the joint provides up to 360 degrees of rotation. Preferably, the light source is adapted to be controlled using primary light controlling means.

Ideally, the primary light controlling means is either a Digital Addressable Lighting Interface or a Doppler Effect Intelligent Light Control. Advantageously, the primary light controlling means further increases the energy management and energy efficiency of the luminaire.

Preferably, the light source comprises aluminium and is reflective.

Ideally, the luminaire provides an electrical connector for connecting to the light source, the electrical connector providing a class 2 earth connection and an external physical earth connection, and the outer body of the luminaire housing is an electrical insulator.

Advantageously, this enables the luminaire to provide three types of electrical safety protection compared to conventional luminaires which generally provide only a class 2 earth connection or no earth terminal at all.

Accordingly, the present invention further provides a luminaire comprising: a luminaire housing defining a cavity adapted to receive and hold a light source in place, the luminaire housing comprising a conductive material, the cavity shaped to reflect light using total internal reflection; and a light source.

Accordingly, the present invention further provides a luminaire comprising: a luminaire housing defining a cavity adapted to receive and hold a light source in place, the luminaire housing comprising a plug having retaining means, the plug being a truncated tubular cone or cylinder; and a light source.

Ideally, the truncated tubular cone being a conical tubular frustum.

The skilled man will appreciate that all preferred or optional features of the invention described with reference to only some aspects or embodiments of the invention may be applied to all aspects of the invention.

It will be appreciated that optional features applicable to one aspect of the invention can be used in any combination, and in any number. Moreover, they can also be used with any of the other aspects of the invention in any combination and in any number. This includes, but is not limited to, the dependent claims from any claim being used as dependent claims for any other claim in the claims of this application.

The invention will now be described with reference to the accompanying drawing which shows by way of example only one embodiment of an apparatus in accordance with the invention.

Figure 1 is a luminaire housing according to an embodiment of the present invention .

Figure 2 is a lateral view of a luminaire housing as shown in Figure 1 .

Figure 3 is an underside perspective view of a luminaire housing as shown in Figure

1 .

Figure 4 is a luminaire housing according to another embodiment of the present invention.

Figure 5 is a lateral view of a luminaire housing as show in Figure 4.

Figure 6 is an underside view of a luminaire housing as shown in Figure 4.

Figure 7 is a detailed view of the retaining arrangement and light source retaining arrangement according to the present invention.

Figure 8 is a lateral view of a luminaire housing according to an embodiment of the present invention.

Figure 9(a) is an exploded view of a luminaire according to an embodiment of the present invention.

Figure 9(b) is an exploded view of a luminaire with an LED light source according to another embodiment of the present invention

Figure 9(c) is an exploded view of a luminaire with a laser light source according to an embodiment of the present invention.

Figure 9(d) is an exploded view of a luminaire with a fibre-optic light source according to an embodiment of the present invention.

Figure 9(e) is a cutaway view of a luminaire according to an embodiment of the present invention. Figure 10 is a rotatable joint according to the present invention.

Figure 1 1 is a luminaire according to the present invention.

Figure 12 is a luminaire mounted in a recess according to the present invention. Figure 13(a) is a cover plate according to the present invention.

Figure 13(b) is a topside view of a cover plate as shown in Figure 13(a).

Figure 13(c) is a lateral view of a cover plate as shown in Figure 13(a).

Referring to the drawings, there is shown a luminaire housing generally indicated by the reference numeral 1 , and defining a cavity (3). The cavity (3) is adapted to receive and hold a light source (2) in place. The luminaire housing (1 ) comprises a composite of an elastomeric material and a conductive material. The ratio of elastomeric material to conductive material is adaptable based on the desired properties of the luminaire housing. For example, the conductive material can comprise up to 1 %, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 99% of the composite.

The conductive material is a metal alloy, non-ferrous metal alloy or a semiconducting material such as silicon, germanium or graphene or a combination thereof. The

semiconducting material can have added dopants to change the insulative and conductive properties of the semiconducting material. The elastomeric material is a flexible elastomeric material such as inorganic elastomeric silicone with between Shore 40 and Shore 60. In some embodiments, the elastomeric material is optically transparent.

The design and construction of the composite material means that the luminaire housing (1 ) inherits material properties from both the elastomer and the composite. For example, the elastomeric material provides the luminaire housing (1 ) with a wide serviceable temperature range; resistance to oxidization, ozone, and UV radiation; non -adhesive properties; low toxicity; and electrically insulative properties. The elastomeric material enables the luminaire housing (1 ) to have low chemical reactivity; be flame retardant; and be easy to manufacture and manipulate. In turn, the conductive material allows the luminaire housing (1 ) to act as a heat sink to transfer thermal energy away from the light source (2), thus making the luminaire housing (1 ) ideally suited for light sources (2) such as LED, laser or fibre optic which require the high transfer of heat energy through conduction, convection and radiation in order to increase their longevity. Meanwhile, the luminaire housing (1 ) can still be used with more conventional light sources such as halogen bulbs.

A portion of the outer surface of the luminaire housing (1 ) can be coated, such as by spray coating, with an insulative material to enhance the outer surface's electrical and thermal insulative properties as compared to conventional luminaires. Furthermore, the metal alloy or semiconducting material and flexible elastomeric material makes the luminaire housing (1 ) relatively cheap as compared to the steel or stainless steel conventional luminaire housings. The use of material also keeps the weight down to 25 grams to 100 grams, and in one embodiment 40 to 70 grams. The non-ferrous or semiconducting materials used are also not prone to oxidation or susceptible to corrosion in moist environments. As a result, the luminaire housing (1 ) of the present invention is ideally suited to be used in environments such as a bathroom or outdoors.

As shown in Figure 12, the luminaire housing (1 ) is adapted to be received, installed, and held-in place in a recess, such as in a ceiling (12). The luminaire housing (1 ) is constructed so that it can be held-in place in the recess without the use of fasteners. To this end, the luminaire housing (1 ) provides a retaining arrangement, the retaining arrangement (4a) extends into the recess. As shown in Figures 1 to 8, the luminaire housing comprises a plug (4) having a plurality of deformable protrusions (4a), the plurality of protrusions (4a) provide the retaining arrangement (4a). The retaining arrangement (4a) is flexible and resilient, and at least part of the retaining arrangement (4a) has at least one diameter larger than the largest diameter of the recess in which it is to be inserted. During installation, the user will push the luminaire housing (1 ) into the recess, and the flexible/resilient nature of the retaining arrangement (4a) will cause the retaining arrangement (4a) to deform to an installation configuration having a smaller diameter so that it can fit inside the recess. Once inside the recess, the flexible/resilient nature of the retaining arrangement (4a) will cause it to attempt to expand outwards to return to its original, expanded, configuration . This causes the retaining arrangement (4a) to transition to an in-use retention configuration where it positively engages with the internal surface of the recess (1 ), holding the luminaire housing (1 ) tightly in place within the recess.

In the in-use retention configuration, the retaining arrangement (4a) will hold the luminaire housing (1 ) in place against the force of gravity or most external impacts, and provides up to seven factor of safety. In order to remove the luminaire housing (1 ) from the recess, the user simply has to pull on the luminaire housing (1 ). This push-pull arrangement for installing/removing the luminaire housing (1 ) makes installation, removal and

maintenance less cumbersome than that of conventional fastener arrangements.

Furthermore, the push-pull arrangement does not cause damage to the recess in which it is installed.

The retaining arrangement (4a) can be permanently formed with the luminaire housing (1 ) such that the material of the retaining arrangement (4a) is homogeneous with the material of the luminaire housing (1 ). However, the retaining arrangement (4a) can also be separate from the luminaire housing (1 ) and configured to be releasably or fixedly positioned over a portion of the outer surface of the luminaire housing (1 ). In this alternative

arrangement, the retaining arrangement (4a) can be constructed from different material to that of the luminaire housing (1 ).

The plug (4) has a plurality of deformable protrusions (4a), for example four protrusions, protruding from the external surface of the luminaire housing by a radial distance in the range 3mm to about 8mm. The plurality of protrusions (4a) are adapted to deform during installation, and then expand outwards to form the in-use retention configuration. The plurality of protrusions (4a) are cut into side walls of the plug (4) and can vary from a coarse thread close to the upper-most end (17) of the plug to a fine thread close to the lower-most end (18) of the plug. In addition, and as shown in Figure 8, the plurality of protrusions (4a) can have a pitch (p) in the range of 3mm to 8mm.

The plug (4) is generally tubular and has a longitudinal axis, the protrusions (4a) are discrete continuous or discontinuous protrusions (4a) spaced apart along the longitudinal axis of the external surface of the plug (4). The discrete continuous or discontinuous protrusions (4a) are ridges, and the pitch between the ridges is constant around the circumference. The discrete continuous or discontinuous protrusions (4a) vary from a coarse thread close to the upper-most end (17) of the plug (4) to a fine discrete continuous thread close to the lower most end (18) of the plug (4).

In one embodiment, the plug (4) is generally tubular and has a constant cross-section along the length of the tube. The plug (4) has a substantially rectangular or circular cross- section.

In another embodiment, the plug (4) is a truncated tubular cone such as an oblique truncated tubular cone or a conical tubular frustum. The plug (4) being a conical tubular frustum is shown in Figure 8, where the upper-most end (17) and lower-most end (18) are parallel, but differently sized. The plug (4) being a truncated tubular cone is advantageous, as the upper-most end (17) of the plug (4) is has a smaller outer circumference and thus can be more easily pushed into the recess. As the plug (4) continues to be pushed into the recess, the width of the plug (4) progressively increases, ensuring that the retaining force generated by the plug (4) is sufficiently large to prevent the luminaire housing (1 ) from falling out of the recess.

In another alternative embodiment, the plug (4) is an oblique truncated tubular cylinder.

The retaining arrangement (4a) can be sized to positively engage with typical ceiling thicknesses of 10mm, 13mm and 27mm, and up to 30mm. By contrast, most conventional luminaire housings are adapted to accommodate up to only 16mm thickness. Of course, the retaining arrangement (4a) can be adapted to fit other sizes of recesses.

As shown in Figures 7, 1 1 and 12, the luminaire housing (1 ) further comprises a sealing arrangement (5), such as a ring or O-ring (5) with a diameter between 30mm to 200mm, 30mm to 100mm, 50mm to 60mm, or 58mm. The ring or O-ring (5) is positioned around the outer circumference of the plug (4) and close to the start of the ventilating hood/cap (9). Advantageously, the ring or O-ring (5) improves the sealing properties of the luminaire housing (1 ). By forming a tight seal in the recess, the retaining arrangement (4a) maintains a high ingress protection (IP) rating of up to 100%.

The light source (2) is held in place in the cavity (3) of the luminaire housing (1 ) using a light source retaining arrangement (6), as shown in Figure 7. The light source retaining arrangement (6) is flexible and resilient and includes a lip/shoulder (6) which extends inwardly from the internal surface of the housing and into the cavity (3). The lip/shoulder (6) can extend inwardly from the internal surface of the plug (4) and be adapted to be positioned proximal to a lower-most end (18) of the plug (4). The lip/shoulder (6) presents a surface that is adapted to engage with the light source (2) when the light source (2) is positioned within the cavity (3) and hold the light source (2) in place. The lip/shoulder (6) comprises a ribbed ring (6) having an undercut with an expandable edge for positive and non-positive accommodation of the light source (2). In one embodiment, the light source retaining arrangement (6) can be permanently formed on the luminaire housing (1 ) such that it is homogeneous with the material of the luminaire housing (1 ). In an alternative embodiment, the light source retaining arrangement (6) is separate from the luminaire housing (1 ) and releasably or fixedly positioned over a portion of the inner surface of the luminaire housing (1 ). In this alternative embodiment, the light source retaining arrangement (6) can be constructed from a different material to that of the luminaire housing (1 ).

Advantageously, the light source retaining arrangement (6) is suitable to hold light sources (2) with a given diameter. Advantageously still, the light source retaining

arrangement (6) allows for light sources (2) to be easily installed or removed from the luminaire housing (1 ) without the use of fasteners.

The light source retaining arrangement (6) has a first normal position protruding into the cavity (3) so as to retain the light source (2) in the cavity (3) and a second deformed configuration allowing a light source (2) to pass into and out of the cavity (3).

In order to install the light source (2), the user simply has to push the light source (2) into the cavity (3), which causes the light source retaining arrangement (6) to deform and receive the light source (2) due to its flexible properties (see Figure 9(a)). The light source retaining arrangement (6) will then expand outwards, due to its resilient properties, so that it engages with and retains the light source (2) in place (see Figure 9(e)). Conversely, in order to remove the light source (2), the user simply has to pull the light source out of engagement with the light source retaining arrangement (6). This push-pull arrangement makes installation, removal, and maintenance less labour intensive, and reduces the risk of damage to the luminaire housing (1 )/light source (2).

As shown in Figures 1 to 6, 8, 9(a)-(e) and 1 1 to 12, the luminaire housing (1 ) comprises a bezel (8), which is either a permanent, integral part of the luminaire housing (1 ) or a releasably attachable addition. By default, the generic bezel (8) is white or other single block colour; however, the back surface of the bezel (8) can be implanted with additives adapted to change the colour of a front face of the bezel (8) to produce a spectrum of different colours.

The bezel (8) extends from the lower-most end (18) of the plug (4) and is flush with or extends out of the recess and into the architectural space. For example, as shown in Figure 12, the luminaire housing (1 ) is adapted to be received and installed in a recess in a ceiling (12). The plug (4) extends into the recess, while the bezel (8) extends out of the recess and into the architectural space. Alternatively, the bezel (8) could be flush with an inlet/opening of the recess.

The bezel (8) is also adaptable to be provided with a secondary light source (not shown) which is adapted to change the colour of a front face of the bezel (8). The secondary light source is driven by a polymer battery (not shown) also installed in a back face of the bezel (8). The secondary light source comprises at least one Red-Green-Blue (RGB) LED. The secondary light source is controllable using a secondary light controlling arrangement such as Infrared or Radio Frequency lighting to change colour and produce a 'mood' light effect whereby the colour of the bezel (8) changes to suit the user's mood or desired ambience. Advantageously, the secondary light source will allow the bezel (8) to glow uniformly throughout the bezel's width. In another embodiment, the bezel (8) is covered with a cover plate (15), which can be clipped or otherwise adhered onto the bezel (8) as shown in Figures 9(a)-(e) and 13(a)-(c). Like the bezel (8), the cover plate (15) can be implanted with additives to change the colour or provided with a secondary light source, polymer battery, and a secondary light controlling arrangement to produce a desired colour effect.

As further shown in Figures 1 to 6, 8, 9(a)-(e) and 1 1 -12, the luminaire housing (1 ) comprises a ventilating hood/cap (9) having at least one vent hole (10), or a plurality of vent holes (10) for heat dissipation. The ventilating hood/cap (9) extends from the upper-most end (17) of the plug (4) and into the recess, as shown in Figure 12. In this arrangement, the plug (4) is sandwiched between the ventilating hood/cap (9) and the bezel (8).

The ventilating hood/cap (9) is a tapered tubular body and can be generally or substantially frustoconical in shape. As detailed in Figure 3, the ventilating hood/cap (9) can comprise vertical rows of vent holes (10) spaced equidistantly apart around the surface of the ventilating hood/cap (9). Each vertical row can have 3 vent holes (1 0), and there can be 8 vertical rows in total. In the ventilating hood/cap (9) at least one of the vent holes (10) is arranged such that when the light source (2) is positioned within the luminaire housing (1 ), an air gap is maintained between the body of the light source (2) and the vent hole (10). In this arrangement, the at least one vent hole (10) provides a route for heat dissipation from the light source (2) by convection. Further, in the ventilating hood/cap (9) at least one of the vent holes (10) is arranged such that when the light source (2) is positioned within the luminaire housing (1 ), the light source (2) directly contacts with the luminaire housing (1 ) at or about the vent hole (10). In this arrangement, the at least one vent hole (10) provides a route for heat dissipation from the light source by conduction and radiation. Advantageously, in combination, the vent holes (10) provide routes for heat transfer from the light source (2) by convection, conduction and radiation. As a result, the luminaire housing's (1 ) thermal management capabilities make it suitable for light sources (2) such as LED and fibre-optic. In some embodiments, extra conductive material can be added to portions of the luminaire housing (1 ) at or about the at least one vent hole (10) to enhance the heat transport properties.

In one embodiment as shown in Figures 1 to 3, the ventilating hood/cap (9) is aligned with the plug (4) to form a straight luminaire housing (1 ). Meanwhile, in another embodiment as shown in Figures 4 to 6, the longitudinal axis of the ventilating hood/cap (9) is positioned at an angle with respect to the longitudinal axis of the plug (4) to form a partly slanted luminaire housing (1 ). In one embodiment, the angle is between 15-45 degrees. In another embodiment, the angle is between 25-35 degrees. In a further preferred embodiment, the angle is 30 degrees. The partly slanted luminaire housing (1 ) advantageously provides light at a slanted angle which is ideally suited for shop accent lighting.

The luminaire housing (1 ) can comprise a cooling heat sink, such as a Peltier thermostatic heat sink, and have a large surface area for transfer of heat energy from the light source (2) to the surrounding environment. Thus increasing its longevity.

In both the first and second embodiments, the luminaire housing (1 ) can be implanted with additives to enhance the fire retardant properties of the luminaire housing (1 ).

Advantageously, the additives can enable the luminaire housing (1 ) to withstand

temperatures from -100°C to 800°C. Advantageously still, in case of fire, the luminaire housing (1 ) does not explode or spread fire, but rather simply melts.

The cavity (3) is advantageously shaped to capture light using total internal reflection. To enhance the reflection of light, a mirror-like film can be provided on the inner surface of the luminaire housing (1 ).

In some alternative embodiments, the luminaire housing (1 ) does not necessarily comprise a composite material.

In one such alternative embodiment, the luminaire housing (1 ) comprises a conductive material and the cavity is shaped to reflect light using total internal reflection. The conductive material can be a metal alloy, non-ferrous metal alloy or a semiconducting material such as silicon, germanium or graphene. In one preferred embodiment, the luminaire housing (1 ) is constructed primarily or entirely from graphene. In another such alternative embodiment, the luminaire housing (1 ) comprises a plug (4) having a retaining arrangement (4a) adapted to hold the luminaire housing (1 ) in place without the use of clips or fasteners, the plug (4) being a truncated tubular cone or cylinder.

In use, a light source (2) is installed in the luminaire housing (1 ) to form the completed luminaire, as shown in Figures 9(a)-(e), 1 1 and 12. The present invention is ideally suited for halogen, LED (Figure 9(b)), laser (Figure 9(c)), and fibre-optic (Figure 9(d)) light sources and can operate under either DCV or ACV mains driverless supply power sources. Advantageously, this makes the luminaire highly flexible. In addition, due to its lower power input but high intensity of luminous flux, the luminaire is also suitable to be driven by renewable sources of energy. The light source (2) comprises aluminium and is reflective.

In one embodiment, the light source (2) is a fibre optic, laser or a LED light source and is adapted to be operated using mains ACV rated at 100 to 270VAC.

In further embodiments, primary lighting control arrangements such as Digital Addressable lighting interface and Doppler Effect intelligent light control can be utilised to control the light source (2) to further increase the energy management and energy efficiency of the luminaire.

In some embodiments, the light source (2) is mounted on a semiconducting substrate, such as a graphene substrate. Advantageously, the graphene substrate is thin and helps to dissipate heat quickly.

The light source (2) can also comprise a semiconducting lens, such as a graphene lens. Advantageously, it has been found that the graphene lens increases transmission of light capture and allows up to 98% transmission of light.

In some embodiments, the light source (2) can be mounted on a joint (1 1 ) providing 360 degrees of rotation as detailed in Figure 10. Advantageously, this allows the orientation of the light source (2) to be changed, providing greater flexibility to the user.

In further embodiments, the luminaire comprises an electrical connector for connecting to the light source (2). The electrical connector is adaptable to provide a class 2 earth connection and an external physical earth connection, and the outer body of the luminaire housing (1 ) is an electrical insulator. Advantageously, this enables the luminaire to provide three types of electrical safety protection compared to conventional luminaires which generally provide only a class 2 earth connection or no earth terminal at all.

In relation to the detailed description of the different embodiments of the invention, it will be understood that one or more technical features of one embodiment can be used in combination with one or more technical features of any other embodiment where the transferred use of the one or more technical features would be immediately apparent to a person of ordinary skill in the art to carry out a similar function in a similar way on the other embodiment.

In the preceding discussion of the invention, unless stated to the contrary, the disclosure of alternative values for the upper or lower limit of the permitted range of a parameter, coupled with an indication that one of the said values is more highly preferred than the other, is to be construed as an implied statement that each intermediate value of said parameter, lying between the more preferred and the less preferred of said alternatives, is itself preferred to said less preferred value and also to each value lying between said less preferred value and said intermediate value.

The features disclosed in the foregoing description or the following drawings, expressed in their specific forms or in terms of a means for performing a disclosed function, or a method or a process of attaining the disclosed result, as appropriate, may separately, or in any combination of such features be utilised for realising the invention in diverse forms thereof as defined in the appended claims.