AU2011204751A1

AU2011204751A1 - Downlight

Info

Publication number: AU2011204751A1
Application number: AU2011204751A
Authority: AU
Inventors: Jason Gerard; David Leske
Original assignee: Gerard Lighting Pty Ltd
Current assignee: Gerard Lighting Holdings Pty Ltd
Priority date: 2010-01-11
Filing date: 2011-01-10
Publication date: 2012-08-02
Also published as: WO2011082457A1

Abstract

Disclosed is a downlight and a downlight housing. In one aspect, the downlight has a base for being received in an aperture in a ceiling. The diameter of any portion from the base to the top of the downlight is less than or substantially equal to the diameter of the base. This allows the downlight to be installed from below the ceiling. In one form, the downlight is an LED downlight.

Description

WO 2011/082457 PCT/AU2011/000022 DOWNLIGHT TECHNICAL FIELD The present invention relates to downlights, and in one form, to downlights having Light Emitting Diodes (LEDs) as their light source. 5 BACKGROUND Downlights are lights that in use, are installed in a recess or hole in a ceiling for example, with the light source facing down and into the room covered by the ceiling. Downlights have become very popular in recent times, however, they suffer from a number of disadvantages. One disadvantage in 10 particular is the difficulty in installing the lights in the ceiling. Since the downlights must be installed into the ceiling space or cavity, it is necessary for the installer to access the ceiling space or cavity, or in some products, remove part or all of a mounting ring or collar securing the downlight to the ceiling. This requirement increases the time, difficulty and complexity of installing and replacing downlights. This can also lead to an increase in the costs of installation. 15 SUMMARY According to one aspect, there is provided a downlight housing for installation in a ceiling space above a ceiling via an aperture in the ceiling, the downlight housing comprising: a top; and 20 a base for location in the aperture; wherein the base has a diameter greater than or substantially equal to a diameter of any other portion of the downlight from the base to the top. In one form, the diameter of the base is about 48mm. 25 In one form, the diameter of the top is less than or equal to about 42mm. In one embodiment, the downlight housing comprises a heatsink. 30 In one form, the heatsink, is in use, able to dissipate at least about 7Watts. In one form, the heatsink is at least about 45mm in length. In another aspect, there is provided a downlight for installation in a ceiling space via an aperture in the 35 ceiling, the aperture in the ceiling having an effective diameter, the downlight comprising: a light source; a light transmission medium; and RilRRTITilTF SHFFT IPill F 2M RO/AII WO 2011/082457 PCT/AU2011/000022 a downlight housing comprising: a top; and a base for location in the aperture; wherein the base has a diameter greater than or substantially equal to a diameter of any other portion of the 5 downlight from the base to the top. In one form, the diameter of the base is about 48mm. In one form, the diameter of the top is less than or equal to about 42mm. 10 In one embodiment, the downlight housing comprises a heatsink. In one form, the heatsink is in use, able to dissipate at least about 7Watts. 15 In one form, the heatsink is at least about 45mm in length. In one form, the light source is one or more Light Emitting Diodes (LEDs). In one embodiment, the downlight further comprises a front face comprising at least one air vent. 20 In one form, the at least one air vent is in fluid communication with a heatsink of the downlight. In another aspect, there is provided a method of installing a downright in a ceiling, the method comprising: 25 accessing a supply electrical connector from below the ceiling via an aperture in the ceiling; connecting the supply electrical connector to a downlight electrical connector of the downlight; inserting the downlight through the aperture in the ceiling; and securing the downlight. 30 In another aspect, there is provided a downlight housing for installation in a ceiling space above a ceiling, via an aperture in the ceiling, the aperture in the ceiling having an effective diameter, the diameter of the top of the downlight housing being less than or substantially equal to the effective diameter of the aperture in the ceiling. 35 In one form, the effective diameter of the aperture in the ceiling is defined by a collar mounted about the aperture in the ceiling. 2 WO 2011/082457 PCT/AU2011/000022 In another form, the effective diameter is defined by the aperture in the ceiling. In one form, the diameter of the top of the downlight housing is less than or equal to about 42mm. 5 In one embodiment, the downlight housing comprises a heatsink. In one form, the heatsink, is in use, able to dissipate at least about 7Watts. 10 In one form, the heatsink is at least about 45mm in length. In another aspect, there is provided a downlight for installation into a ceiling space via an aperture in the ceiling, the aperture in the ceiling having an effective diameter, the downlight comprising: a light source; 15 a lens; and a downright housing; wherein the diameter of the top of the downlight housing is less than or substantially equal to the effective diameter of the aperture in the ceiling. 20 In one form, the effective diameter of the aperture in the ceiling is defined by a collar mounted about the aperture in the ceiling. In another form, the effective diameter is defined by the aperture in the ceiling. 25 In one form, the diameter of the top of the downlight housing is less than or equal to about 42mm. In one form, the downright housing comprises a heatsink. In one form, the downlight further comprises a front face comprising at least one air vent. 30 In one form, the at least one air vent is in fluid communication with a heatsink of the downlight. According to another aspect, there is provided a downlight for installation into a ceiling space above a ceiling, the downlight comprising: 35 a downlight housing; a light source within the downlight housing; and a front face through at least a part of which light from the light source is transmitted; wherein 3 WO 2011/082457 PCT/AU2011/000022 the front face comprises at least one aperture to provide an air vent. In one form, the downlight housing comprises a heatsink. 5 In one form, the air vent is in fluid communication with the heatsink. In one form, the front face comprises a plurality of apertures to provide air vents. In one form, the plurality of air vents are arranged around a periphery of the front face. 10 According to another aspect, there is provided a downlight for installation into a ceiling space above a ceiling, the downlight comprising: a downlight housing; a light source within the downlight housing; 15 a front face; a light transmission medium at the front face through which light from the light source is transmitted; and a retaining clip securing the light transmission medium in place. 20 In one form, light transmission medium is a lens. In another form, the light transmission medium is a diffuser. According to yet a further aspect, there is provided a method of replacing a light transmission medium 25 in a downlight, the method comprising: removing a retaining clip from the downlight; removing the light transmission medium from the downlight; inserting a different light transmission medium into the downlight; and replacing the retaining clip into the downlight. 30 In one form, each step of the method is performed while the downlight is installed. In another aspect, there is provided a downlight housing for installation in a ceiling space above a ceiling via an aperture in the ceiling, the downlight housing comprising: 35 a top; and a base for location in the aperture; wherein 4 WO 2011/082457 PCT/AU2011/000022 the base has a footprint greater than or substantially equal to a footprint of any other portion of the downlight housing from the base to the top. In another aspect, there is provided a downlight for installation in a ceiling space via an aperture in the 5 ceiling, the downlight comprising: a light source; a light transmission medium; and a downlight housing comprising: a top; and 10 a base for location in the aperture; wherein the base has a footprint greater than or substantially equal to a footprint of any other portion of the downright from the base to the top. Broadly then, there is described a downlight and a downlight housing. In one aspect, the downlight has 15 a base for being received in an aperture in a ceiling. The diameter or footprint of any portion from the base to the top of the downlight is less than or substantially equal to the diameter or footprint of the base. This allows the downlight to be installed from below the ceiling. In one form, the downlight is an LED downlight. 20 DRAWINGS The various aspects will now be described in detail with reference to the following figures in which: Figure 1 - shows a typical application of a plurality of downlights; Figure 2 - shows a rear perspective view of a downlight according to one aspect; 25 Figure 3 - shows a front perspective view of the downlight of Figure 2; Figure 4 - shows a side view of the downlight of Figures 2 and 3 installed in a ceiling space through the ceiling aperture; Figure 5 - shows a rear perspective view of a modified form of the downlight of Figures 2 and 3; 30 Figure 6A - shows a first step of installing the downlight into the ceiling space; Figure 6B - shows a further step of installing the downlight into the ceiling space; Figure 6C - shows the downlight installed in the ceiling space after the steps shown in Figures 6A and 6B; Figure 7 - shows a rear perspective view of a further modified form of the downlight; 35 Figure 8 - shows a front perspective view of the downlight of Figure 7; Figure 9A - shows a front face of the downlight with apertures; Figure 9B - shows an alternative front face of the downlight with no apertures; 5 WO 2011/082457 PCT/AU2011/000022 Figure 10 - shows an exploded view of the components of the downright; Figure 11 A - shows a top view of the LED mounting disc; Figure 1 B - shows a side view of the LED mounting disc of Figure 11 A; Figure I IC - shows a front view of the LED mounting disc of Figure 11 A; 5 Figure l ID - shows an underside view of the LED mounting disc of Figure II A; Figure 12 - shows another arrangement of Figure 4; Figure 13A - shows a perspective view of the downlight retaining ring of Figure 12; Figure 13B - shows a top view of the downlight retaining ring of Figure 13A; Figure 14 - shows another arrangement of Figure 4; 10 Figure 15 - shows a further arrangement of Figure 4; Figure 16 - shows yet a further arrangement of Figure 4; Figure 17A - shows yet a further arrangement illustrating multiple aperture diameters; Figure 17B - shows the collar of Figure 17; 15 Figure 18 - shows a side view of an embodiment of the downlight and/or housing of one aspect; Figure 19 - shows a side view of an alternative embodiment of the downlight and/or housing ofF igure 18; Figure 20A - shows a downlight and/or downright housing according to another 20 aspect; Figure 20B - shows the downlight or downlight housing of Figure 20A installed; Figure 20C -shows a variation of the housing or downlight of Figure 20A; Figure 20D - shows a further variation of the housing or downlight of Figure 20A; Figure 20E - shows a further variation of the housing or downlight of Figure 20A; 25 Figure 20F - shows a further variation of the housing or downright of Figure 20A; Figure 21 - is a flowchart of a method of installing a downright; Figure 22A - shows a downlight according to another aspect relating to an air vent; Figure 22B - shows a different view of the downlight of Figure 22A; Figure 23 - shows a side view of the downright of Figure 22A; 30 Figure 24 - shows a downlight with a plurality of air vents; Figure 25A - shows a first stage in changing a lens of the downlight; Figure 25B - shows a second stage in changing the lens of the downlight; Figure 25C - shows a third stage in changing the lens of the downlight; Figure 25D -shows the final stage in changing the lens of the downlight; and 35 Figure 26 - is a flowchart of a method of changing a lens in the downlight. DETAILED DESCRIPTION 6 WO 2011/082457 PCT/AU2011/000022 Figure 1 shows a typical application of a plurality of downlights 100 installed in a ceiling space (not shown) above ceiling 2, to illuminate room space 1. Downlights 100 when installed, may be completely flush with the surface of ceiling 2 and not protrude into room space 1, or may protrude slightly beyond the surface of the ceiling 2 into room space I as will be appreciated by the person 5 skilled in the art. While the various embodiments presented herein will be described with reference to downlights having Light Emitting Diodes (LEDs) as the light source, it will be appreciated that downlight 100 may have any suitable light source, including halogen, incandescent and/or Light Emitting Diode 10 (LED), or a combination of one or more of these. Figure 2 shows a rear perspective view of a downlight 100 according to one aspect described herein. In this embodiment, downlight 100 has a body or housing 110 which is formed as a heatsink to dissipate heat generated by 1he light source, into the ceiling space. In this example, the heatsink has 5 15 fins 11l extending from each of two sides of the downlight 100. At the rear or top of downlight 100, there is shown a downlight electrical connector 150, which may be provided as a recess, or as a protrusion, to connect to an electrical connector as will be described in more detail below. Figure 3 shows a front perspective view of the downlight 100 of Figure 2. In this view, there can be 20 seen downlight housing 110 with heatsink fins 111, base 112 with lip 113, and lens 130 retained to downlight housing 10 by retaining clip 120. Lip 113 has one or more notches 114, the purpose of which will be described in more detail further below. Figure 4 shows the downlight 100 installed in the ceiling space 5. It is shown secured to collar 3. The 25 manner of securement can be by any suitable means as will be understood by the person skilled in the art. As can be seen in Figure 4, downlight housing 110, in this embodiment, comprises a heatsink with fins 111 as shown in Figures 2 and 3. The heatsink assists in radiating heat generated by the light sources (e.g. LEDs) into the ceiling space 5. 30 While most of the examples provided herein show the housing 1 10 comprising a heatsink with fins 111, it will be appreciated that the various aspects described herein are equally applicable to downlights without a heatsink body, such as that shown in Figure 5. Figure 5 shows a downlight 100 with housing 110 which comprises a plain surface, with a downlight electrical connector 150. 35 Figures 6A to 6C show the downlight 100 and a method of installing the downlight, according to one aspect. In this aspect, it can be seen that the maximum diameter 01 of the downlight 100 is less than or equal to the diameter 02 of the aperture 4 in the ceiling 2, as defined by collar 3 In particular, 0 is the 7 WO 2011/082457 PCT/AU2011/000022 maximum diameter of the downright 100 that will not protrude into the room space I once the downlight is installed, and it will be understood that portions of the downlight 100, such as for example, lip 113, which may protrude beyond the lower surface of ceiling 2 into room space 1, may have a diameter greater than that of the aperture as defined by collar 3. 5 With this arrangement, it is therefore possible to install downlight 100 from below ceiling 2 rather than from above ceiling 2 in ceiling space 5. Because downlight diameter 01 is equal to or less than aperture diameter 02 , downlight 100 may be slid into ceiling space 5 through the aperture 4, from below. 10 Figure 6A shows the first step of installation of downlight 100, in which an electrical supply system is accessed by, for example, pulling lead 211 and supply electrical connector 210 through the aperture 4, and inserting supply electrical connector 210 into downlight electrical connector 150 (see Figures 2 and 5 for example). 15 The downlight 100 is then inserted into aperture 4 as shown in Figure 6B, until it is fully inserted (for example, until a portion of downlight 100 that has a diameter greater than the diameter of aperture 4 reaches aperture 4, or as determined by any other suitable means), as shown in Figure 6C. Downlight 100 is then secured to collar 3 or other securement point as will be understood by the person skilled in 20 the art. In one embodiment, the maximum diameter 01 is less than or equal to about 50mm. In another embodiment, the maximum diameter 01 is less than or equal to about 42mm. It will be understood that it is possible for the maximum diameter 01 to be equal to the diameter 02 of the aperture 4, and still be 25 able to pass through, due to some minimal compression and/or mechanical deformation. In the case where the maximum diameter is less than the aperture diameter, the downlight 100 will pass through aperture 4 easily. It will also be understood that downlight 100 may take on other dimensions and proportions, within 30 the constraints of the diameter relationships set out above. For example, downlight 100 can be a squatter configuration as shown in Figures 7 and 8, with like elements numbered accordingly. Another aspect is illustrated in Figure 9A, which shows apertures 121 in a front face 102 of downlight 100, in this example, in retaining clip 120 which retains light transmission medium 130, which is in 35 this case a lens. Front face 102 in this example is the face that is visible from the room space I when the downlight 100 is installed and is in this example, provided by light transmission medium or lens 130, retaining clip 120 and lip 113. Apertures 121 provide for airflow through the apertures, which are 8 WO 2011/082457 PCT/AU2011/000022 in fluid communication with channels formed between fins I11 via fin apertures IIla as shown for example, in Figure 7. This enables convection currents to be established, which further increase the efficiency of the heat dissipation provided by the heatsink of downlight housing I 10. 5 In one example, as shown in Figures 2, 3, 7 and 8, there are provided 5 fins on each side, with a 7mm pitch. Of course, it will be appreciated that the provision of apertures 121 is optional, and in some embodiments, there may not be these apertures, as is illustrated in Figure 9B. 10 Figure 10 shows an exploded view of the components of one embodiment of downlight 100, illustrating the simplicity of the construction. Downlight housing 110 (in this example comprising a heatsink with fins 111) provides the main body of downlight 100. Light source 180 (for example one or more Light Emitting Diodes or LEDs) is mounted on to an LED mounting disc 160. The LEDs are 15 electrically connected to the power supply via LED connector pins 161 (see Figure I1) and Printed Circuit Board (PCB) 170. PCB 170 is in turn electrically connected to downlight electrical connector 150. PCB 170 may be mounted to housing 110 into a PCB slot and may be clipped into the heatsink vent holes or apertures, to thereby expose the PCB to the cooling convection currents to maintain appropriate operating temperatures of the circuitry on PCB 170. 20 Light transmission medium 130 (for example a lens) is placed in the base 112 of the downlight 100 and may be retained therein by retaining clip 120. In one example, retaining clip 120 comprises a clip with clip fingers 121 that engage with corresponding recesses in the housing 110, that allows easy removal from downlight 100 even when downlight 100 is installed in the ceiling 2. This allows easy 25 replacement of the lens 130 by simply unclipping the retaining clip from the base 112, removing the current lens 130, inserting a new light transmission medium 130' (for example new lens 130') and re clipping the retaining clip 120 into the base 112. This allows the consumer to easily change the lens or light transmission medium, for example to vary the lighting effect such as beam angle or to replace the lens with a diffuser, without the need of a professional installer or removing the installed downlight 30 100. The assembled product is as shown in Figures 2, 3, 7 or 8. As can be seen in Figures 2, 3, 7, 8, 9A, 9B and 10, there is shown one or more notches 114 in lip 113. 35 These may be used to engage with corresponding protrusions in collar 3 in the ceiling 2. If the corresponding protrusions in the collar do not align with the notches 114, the downlight 100 will not 9 WO 2011/082457 PCT/AU2011/000022 be able to be installed. This acts to prevent a downlight of a different or non-conforming type being installed in a preinstalled collar. This optional feature will be described in more detail further below. Turning now to Figure 11, LED mounting disc 160 is shown in more detail. Figure 11 A shows a top 5 view of disc 160. In one example, LEDs 180 (see Figures 1 IB, 11 C and IID) mounted to the underside of disc 160 (see Figure lI D) are electrically connected to a power supply via LED connector pins 161 which pass from the mounting side facing the base of downlight 100, through a disc aperture 162, to the top side of disc 160, for connection to the power supply via PCB 170 and downlight electrical connector 150 as previously described. LED connector pins 161 incorporate an 10 insulating part 163 to prevent short circuiting of pins 161 to any other conductive element on disc 160. This "pass-through" arrangement may be seen more clearly in Figures II B and 1 IC. Figure 1ID shows the opposite side, or underside view, of disc 160, showing pins 161 for electrical connection to PCB 170. 15 Figure 12 shows a particular practical arrangement in which a collar 3 is inserted into the aperture in the ceiling 2 and retained therein via spring-loaded arms 3a and 3b as will be understood by the person skilled in the art. Downlight 100 is then inserted into a downlight retaining ring 6 (see Figures 13A and 13B) which may be retained therein by various means, including screw fir, friction fit, or further spring retainers contained on retaining ring 6. The assembly of the downlight 100 and the retaining 20 ring 6 is then inserted through the aperture formed by the inner or minimum diameter of collar 3 designated at 3c and secured thereto by various possible means including a bayonet or other locking or screwing means. Figure 13A shows a perspective view of downlight retaining ring 6, with wall 6a, outer flange 6b, 25 inner platform 6c and, in one embodiment, protrusion 6d. Figure 13B shows a top view of downlight retaining ring 6 with like elements labelled accordingly. In this embodiment, protrusions 6d locate with notches 114 in lip 113 of downlight 100 as previously described. If a downlight does not have corresponding notches 114, the downlight will not be able to be retained by downlight retaining ring 6. This prevents a non-conforming downlight to be installed in place of a conforming one. Of course, it 30 will be understood that any other arrangement such as 1, 3, 4 or more notches 114 and corresponding protrusions 6d may be provided in any arrangement, and in fact notches 114 may be replaced by protrusions and protrusions 6d may be replaced by corresponding notches. Other means of installing a downlight are also possible, including the provision of a collar or other 35 retaining means installed in the ceiling space 5 from above ceiling 2. In this case, the aperture through which the downlight 100 must pass is that defined by the ceiling aperture 4 itself. Thus, in some cases, the aperture will be defined by the collar and in others, by the ceiling aperture. Figure 14 shows such 10 WO 2011/082457 PCT/AU2011/000022 an arrangement in which a collar 3 is installed from above ceiling 2 to retain downlight 100 with retainers 3b. In this case, the aperture 4 through which at least a portion of the downlight 100 must pass is that defined by the ceiling shown as 02. 5 In other arrangements, the collar may support a gimball 7 as shown in Figure 15. In this arrangement, at least the top of downlight 100 must be able to pass through the minimum diameter, or "effective" diameter, which in this case, is defined by the top opening of gimball 7, indicated again as 02. In a further possible arrangement, a collar 3 may be formed so as to have 2 or more diameters, to allow 10 for example, a part of the downlight 100 to be recessed into the collar and the top part of the downlight to pass through to the ceiling space 5, through a second or subsequent diameter. In Figure 16, this arrangement is shown in which the effective diameter 02 is shown at the top of the collar 3, as well as a lower, larger diameter, shown at the bottom of collar 3, shown as diameter 03. Thus in these arrangements, it will be appreciated that the maximum diameter of the downlight need not be less than 15 or equal to all diameters provided by the collar. In one embodiment in fact, it is sufficient that the diameter 05 of the top of the downlight 100 is less than or equal to the effective or minimum diameter of the aperture defined by the collar or the aperture in the ceiling itself, to allow the top of the downlight 100 to access the ceiling space 5 for more 20 efficient heat dissipation. Figure 17A shows an arrangement in which the collar 3 presents a number of apertures of different diameters. In this case, the largest, 01, is at the lowest opening of the collar with respect to the installer, 03 receives the lip 113 of downlight 100, 04 receives a lower portion of the downlight 25 housing 110 and the smallest, or effective diameter 02, allows the top 101 of the downlight 100 to pass through it and into the ceiling space 5. Figure 17B shows the collar 3 with the various diameters described above. 30 Figure 18 shows a specific embodiment of the downlight housing 110 and/or downlight 100. At the bottom or lip of the housing/downlight, the diameter is about 50mm. At the base, the diameter is about 48mm. At about 20.25mm from the bottom of the housing/downlight, the diameter is about 42mm. At the top of the housing/downlight, the diameter is about 39mm, but may be less than or equal to about 42mm. In one embodiment, the top of the housing/downlight is about 80mm high from the bottom. 35 Figure 19 shows another possible embodiment of a shorter housing/downlight. In this embodiment, the lip or bottom the diameter is about 50mm. At the base, the diameter is about 48mm. At about 11 WO 2011/082457 PCT/AU2011/000022 20.25mm from the bottom of the housing/downlight, the diameter is about 42mm. At the top of the housing/downlight, the diameter is about 39mm but may be less than or equal to about 42mm. In this embodiment, the top of the housing/downlight is about 60mm high from the bottom. 5 In both embodiments shown in Figures 18 and 19, the length of the heatsink is at least about 45mm, and in some embodiments, can range between about 45mm to about 100mm, including about 45mm, about 50mm, about 60mm, about 70mm, about 80mm, about 90mm, about 95mm and about 100mm. These approximate dimensions, together with the design of the housing and heatsink portion, allow the 10 downlight and/or housing to dissipate more than about 7 watts of power, and in some embodiments, including about 7W to about 15W, including about 7.5W, about 8W, about 8.5 W, about 9W, about 9.5W, about 10W, about 10.5W, about 11W, about 11.5W, about 12W, about 12.5W, about 13W, about 13.5, about 14W, about 14.5W, and about 15W. 15 There is therefore described in one aspect as shown in Figures 20A to 20F, a downlight housing 1 10 for installation in a ceiling space above a ceiling via an aperture in the ceiling, the downlight housing 110 comprising a top 10 1 and a base 112 for -location in the aperture. In this aspect, the base 112 has a diameter Obase greater than or substantially equal to a diameter of any other portion of the downlight from the base 112 to (and including) the top 101. The diameter of any other portion is illustrated in 20 Figure 20A as diameters OA, OB, OC, OD, OE, OF, OG,0H, 01 and Otop. These are representative examples of any portion of the housing 110 from the base 112 to the top 101. As can be seen in Figure 20A, the diameters of any of these portions are less than or substantially equal to the diameter Obase of base 112. 25 In the example in Figure 20A, the lip 113 can have a diameter greater than the diameter Obase of the base 112. In practice, when the downlight 100 or housing 110 is installed in the aperture of the ceiling, lip 113 may protrude into the room space as previously described and as shown again in Figure 20B. Figure 20C, 20D, 20E and 20F show further possible variations and configurations that are possible in 30 accordance with this aspect. In one example as shown in Figure 20E, base 112 that is located in the aperture when installed, may itself have a range of diameters, however in these cases, the diameter Obase of the base 112 will be taken to be the largest diameter of the portion that is received within the aperture of the ceiling.

35 In another embodiment, as shown in Figure 20F, the base and the remainder of the downlight housing or downlight form a cylinder with the diameter of all portions all the way to the top from the base are the same or substantially the same as that of the base. 12 WO 2011/082457 PCT/AU2011/000022 In other embodiments, as shown in Figures 20C and.20D, the diameter of some portions can be less than the diameter of the base while the diameter of other portions can be substantially equal to the diameter of the base and this may vary over the length of the housing or downlight from the base to 5 the top. In other embodiments, the base I12 is not circular has thus has no well defined "diameter". In these embodiments, the edge of base 112 defines a footprint of the base. In this aspect, no part of any of the portions above the base extends beyond the footprint defined by the diameter. In some embodiments, 10 the footprint is square. In some embodiments, the footprint is rectangular. In some embodiments the footprint is octagonal. In some embodiments, the footprint is hexagonal. It will be understood that the footprint can be any 2-dimensional shape. In some embodiments, at least a part of one or more other portions above the base can extend to the 15 edge of the footprint. In other embodiments, the other portions will lie within the footprint. Accordingly, the footprint of the base is greater than or substantially equal to a footprint of any other portion of the downlight or downright housing from the base to the top. As shown in Figures 18 and 19, in one embodiment, the diameter of the base 112 is about 48mm and 20 the diameter of the top 101 is about 39mm. The above description with reference to Figures 18 to 20E is equally applicable to a downlight 100 which comprises the housing I 10 plus a light source 180 and a transmission medium 130 housed by the housing. 25 Figure 21 is a flowchart of the method of installing a downlight as shown with reference to Figures 6A to 6C. In step 500, an electrical supply connector 210 is accessed from the ceiling space via the aperture in the ceiling 2. In step 510, the supply connector 210 is connected to the downlight 100. In step 520, the downlight 100 is inserted into the ceiling space via the aperture and then in step 530, the 30 downlight 100 is secured. The downlight may be secured by various means including securing to a collar 3 mounted about the aperture in the ceiling, as in Figure 6C for example, or to a gimbal 7 as shown in Figure 15 for example. Figure 22A shows a downlight 200 exhibiting another aspect. This aspect relates to the provision of an 35 aperture 240 in a front face 260 of the downlight 200. In some embodiments, and as illustrated in the embodiment of Figure 22A, the front face 260 comprises a rim 220 surrounding a light transmission medium 230 such as a lens 230at the front face, and is the face that is exposed to the room I when the 13 WO 2011/082457 PCT/AU2011/000022 downlight is installed. Aperture 240 provides an air vent that allows hot air generated about the downlight 200 in the ceiling space when in use, to exit into the larger room space. Figure 22B shows a different perspective view of the downlight 200 showing a corresponding aperture 241 above the base of the downlight 200. Between the aperture 240 and corresponding aperture 241 is a channel 242 5 which allows air to flow from around the main body of downlight 200 and from around heatsink 250 into corresponding aperture 241, through channel 242 and out aperture or air vent 240 to be expelled into the larger room space. This allows aperture 240 to be in fluid communication with the heatsink 250 and/or the air space about the main body of the downlight 250. 10 Figure 24 shows an embodiment in which the front face comprises a plurality of apertures 240a, 240b, 240c, 240d, 240e, 240f, 240g and 240h. It will be appreciated that any number of apertures 240 could be provided as suitable, including 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 or more apertures. It will also be appreciated that in some embodiments such as illustrated in Figure 24, no heatsink is present, while in other embodiments, such as shown in Figures 8, 22A, 22B and 23 for example, there 15 is a heatsink. Figures 25A to 25D show a series of steps according to another aspect. This aspect relates to the ability to replace a light transmission medium such as a lens or a diffuser, from below, when the downlight is installed, without having to remove the downlight from its installed position. 20 In one embodiment, this aspect is facilitated by the provision of retaining clip 120 which in this embodiment, also provides rim 220 as shown in Figure 22A. Thus retaining clip 120 can in some embodiments, also have apertures 121 or 240 as previously described, however, in this aspect, there need not be any apertures. 25 In Figure 25A, it can be seen that retaining clip 120 holds light transmitting medium 130 in place in downlight 100 at the front face of the downlight. In this embodiment, light transmitting medium 130 is a lens, however, this could equally be other light transmitting media such as a diffuser, or an otherwise transparent or translucent disc. Light source 160 in this embodiment is one or more LEDs, but could 30 equally be any other suitable light source. As shown in Figure 25B, retaining clip 120 is removed from the downlight by unclipping retaining clip 120 via clips 121 and pulling it away from downlight 100. Lens 130 then also comes free from downlight 100, in some embodiments, by the mere virtue of gravity. 35 14 WO 2011/082457 PCT/AU2011/000022 In Figure 25C, lens 130 is replaced with a new lens 130'. This may be desired simply to change the effect of the light transmission to provide a more focussed light path or a more diffuse one. In some cases, a coloured disc 130 may be inserted to provide a coloured light output. 5 In Figure 25D, retaining clip 120 is clipped back into downlight 100 with the new lens 130' in place and the replacement is complete. Figure 26 is a flowchart of the steps of the method of replacing the light transmitting medium as described above with reference to Figures 25A-25D. This example refers to the replacement of a lens, 10 but it will be appreciated that the method and steps could equally be applicable to the replacement of any light transmitting medium, including those listed previously. In step 600, the retaining clip 120 is removed from the installed downlight. In step 610, the lens 130 (or other light transmitting medium) is removed from the installed downlight. In step 620, a new or different lens 130 (or other light transmitting medium) is inserted into the downlight and then in step 630, the retaining clip 120 is 15 replaced in the downlight 100 to complete the replacement process. In one example, the steps of the method of Figure 26 are performed while the downlight 100 is already installed. This provides a significant advantage in that a user is able to replace the light transmitting medium 130 without having to uninstall the downright from the ceiling or wall, or other installed 20 location. While the various aspects of the present invention have been described with reference to specific embodiments, it will be understood that these are for illustrative purposes and not to be regarded as limiting the scope of the invention to those embodiments. 25 Throughout the specification and the claims that follow, unless the context requires otherwise, the words "comprise" and "include" and variations such as "comprising" and "including" will be understood to imply the inclusion of a stated integer or group of integers, but not the exclusion of any other integer or group of integers. 30 The reference to any prior art in this specification is not, and should not be taken as,- an acknowledgement of any form of suggestion that such prior art forms part of the common general knowledge. 15

Claims

1. A downlight housing for installation in a ceiling space above a ceiling via an aperture in the ceiling, the downlight housing comprising: a top; and 5 a base for location in the aperture; wherein the base has a diameter greater than or substantially equal to a diameter of any other portion of the downlight housing from the base to the top.

2. A downlight housing as claimed claim I wherein the diameter of the base is about 48mm. 10

3. A downlight housing as claimed in any one of claims I or 2 wherein the diameter of the top is less than or equal to about 42mm.

4. A downlight housing as claimed in any one of claims 1 to 3 wherein the downlight housing 15 comprises a heatsink.

5. A downlight housing as claimed in claim 4 wherein the heatsink, is in use, able to dissipate at least about 7Watts. 20

6. A downlight housing as claimed in any one of claims 4 or 5 wherein the heatsink is at least about 45mm in length.

7. A downlight for installation in a ceiling space via an aperture in the ceiling, the aperture in the 25 ceiling having an effective diameter, the downlight comprising: a light source; a light transmission medium; and a downlight housing comprising: a top; and 30 a base for location in the aperture; wherein the base has a diameter greater than or substantially equal to a diameter of any other portion of the downlight from the base to the top.

8. A downlight as claimed claim 7 wherein the diameter of the base is about 48mm. 35

9. A downlight as claimed in any one of claims 7 or 8 wherein the diameter of the top is less than or equal to about 42mm. 16 WO 2011/082457 PCT/AU2011/000022

10. A downlight as claimed in any one of claims 7 to 9 wherein the downlight housing comprises a heatsink. 5

11. A downlight as claimed in claim 10 wherein the heatsink, is in use, able to dissipate at least about 7Watts.

12. A downlight as claimed in any one of claims 10 or 11 wherein the heatsink is at least about 45mm in length. 10

13. A downlight as claimed in any one of claims 7 to 12 wherein the light source is one or more Light Emitting Diodes (LEDs).

14. A downlight as claimed in any one of claims 7 tol3 further comprising a front face comprising 15 at least one air vent.

15. A downlight as claimed in claim 14 wherein the at least one air vent is in fluid communication with a heatsink of the downlight. 20

16. A method of installing a downlight in a ceiling, the method comprising:' accessing a supply electrical connector from below the ceiling via an aperture in the ceiling; connecting the supply electrical connector to a downlight electrical connector of the downlight; inserting the downlight through the aperture in the ceiling; and 25 securing the downlight.

17. A downlight housing for installation in a ceiling space above a ceiling, via an aperture in the ceiling, the aperture in the ceiling having an effective diameter, the diameter of the top of the downlight housing being less than or substantially equal to the effective diameter of the aperture in the 30 ceiling.

18. A downlight housing as claimed in claim 17 wherein the effective diameter of the aperture in the ceiling is defined by a collar mounted about the aperture in the ceiling. 35

19. A downlight housing as claimed in claim 17 wherein the effective diameter is defined by the aperture in the ceiling. 17 WO 2011/082457 PCT/AU2011/000022

20. A downlight housing as claimed in any one of claims 17 or 18 wherein the diameter of the top of the downlight housing is less than or equal to about 42mm.

21. A downlight housing as claimed in any one of claims 17 to 20 wherein the downlight housing 5 comprises a heatsink.

22. A downlight housing as claimed in claim 21 wherein the heatsink, is in use, able to dissipate at least about 7Watts. 10

23. A downlight housing as claimed in any one of claims 21 or 22 wherein the heatsink is at least about 45mm in length.

24. A downlight for installation into a ceiling space via an aperture in the ceiling, the aperture in the ceiling having an effective diameter, the downlight comprising: 15 a light source; a lens; and a downlight housing; wherein the diameter of the top of the downlight housing is less than or substantially equal to the effective diameter of the aperture in the ceiling. 20

25. A downlight as claimed in claim 24 wherein the effective diameter of the aperture in the ceiling is defined by a collar mounted about the aperture in the ceiling.

26. A downlight as claimed in claim 24 wherein the effective diameter is defined by the aperture 25 in the ceiling.

27. A downlight housing as claimed in any one of claims 24 or 25 wherein the diameter of the top of the downlight housing is less than or equal to about 42mm. 30

28. A downlight as claimed in any one of claims 24 to 27 wherein the downlight housing comprises a heatsink.

29. A downlight as claimed in claim 24 further comprising a front face comprising at least one air vent. 35

30. A downright as claimed in claim 29 wherein the at least one air vent is in fluid communication with a heatsink of the downlight. 18 WO 2011/082457 PCT/AU2011/000022

31. A downlight for installation into a ceiling space above a ceiling, the downlight comprising: a downlight housing; a light source within the downlight housing; and 5 a front face through at least a part of which light from the light source is transmitted; wherein the front face comprises at least one aperture to provide an air vent.

32. A downlight as claimed in claim 31 wherein the downlight housing comprises a heatsink. 10

33. A downlight as claimed in claim 32 wherein the air vent is in fluid communication with the heatsink.

34. A downlight as claimed in any one of claims 31 or 32 wherein the front face comprises a plurality of apertures to provide air vents. 15

35. A downlight as claimed in claim 34 wherein the plurality of air vents are arranged around a periphery of the front face.

36. A downlight for installation into a ceiling space above a ceiling, the downlight comprising: 20 a downlight housing; a light source within the downlight housing; a front face; a light transmission medium at the front face through which light from the light source is transmitted; and 25 a retaining clip securing the light transmission medium in place.

37. A downlight as claimed in claim 36 wherein the light transmission medium is a lens.

38. A downlight as claimed in claim 36 wherein the light transmission medium is a diffuser. 30

39. A method of replacing a light transmission medium in a downlight, the method comprising: removing a retaining clip from the downlight; removing the light transmission medium from the downlight; inserting a different light transmission medium into the downlight; and 35 replacing the retaining clip into the downlight. 19 WO 2011/082457 PCT/AU2011/000022

40. A method as claimed in claim 39 wherein each step of the method is performed while the downlight is installed.

41. A downlight housing for installation in a ceiling space above a ceiling via an aperture in the 5 ceiling, the downlight housing comprising: a top; and a base for location in the aperture; wherein the base has a footprint greater than or substantially equal to a footprint of any other portion of the downlight housing from the base to the top. 10

42. A downlight for installation in a ceiling space via an aperture in the ceiling, the downright comprising: a light source; a light transmission medium; and 15 a downlight housing comprising: a top; and a base for location in the aperture; wherein the base has a footprint greater than or substantially equal to a footprint of any other portion of the downlight from the base to the top. 20