Field of the Invention

The present invention relates to downlights. It is particularly applicable, but in no way limited, to downlights where insulation material is or will be laid over the rear of the downlight.

Background to the invention

Downlights or downlighters are becoming more and more widely used as light sources in domestic and commercial environments. They are particularly neat and unobtrusive in their appearance, since almost the entire downlight fitting is concealed behind a ceiling or other suitable panel or surface, whilst giving out a pleasing light. However, downlights suffer from a number of disadvantages. Firstly, their installation generally requires an aperture to be cut in a ceiling or other surface and that surface generally has a fire rating of typically 30 minutes to 90 minutes. Downlights are generally installed into an aperture in the ceiling that has to be relatively wide to accommodate the downlight assembly and thereby compromises the ability of the ceiling to contain a fire in a room or even a fire caused by the light fitting itself failing. In order to compensate against these increased risks, it is generally required that downlights incorporate adaptations to improve their fire barrier capabilities and which typically include the provision of intumescent materials associated with the downlight assembly and which expand in the heat of a fire to occlude the openings defined by the downlight.

Secondly, downlights generate significant amounts of heat. It is therefore necessary to provide ventilation apertures through which this heat can escape. These ventilation holes are necessary for both the efficient running and operation of the downlight and to prevent the intumescent material from being triggered by the high levels of heat that would otherwise build up within the downlight. The optimum location for these ventilation holes is on the otherwise closed end of the downlight casing or can, opposite to the face of the downlight from which light is emitted. This is because more often than not a downlight is installed in a horizontal surface such as a ceiling and, by having the apertures in the end of the can, heat which is naturally rising away from the bulb can continue to rise uninterrupted. However, ventilation holes in the rear face or end of the can of a downlight may become blocked or compromised if there is insulation material in the space above the ceiling or surface in which the downlight is mounted. In the worst case scenario an insulation blanket can completely close off these ventilation holes, leading to premature failure of the fitting or to unwanted activation of the intumescent material. In either case the fitting will need to be replaced.

It is therefore an object of the present invention to overcome or at least mitigate some or all of the problems outlined above.

Summary of the Invention

According to a first aspect of the present invention there is provided a ventilation cover assembly for a downlight in which a can of the downlight includes ventilation holes, said ventilation cover assembly comprising:-

(i) attachment means adapted to attach the ventilation cover assembly to a downlight can;

(ii) cover means adapted to distance insulation material or the like away from the ventilation holes in a downlight can.

By providing a feature that prevents insulating material or other material from blocking ventilation holes in the downlight can, proper ventilation is maintained, even under an insulation blanket

Preferably the attachment means comprises a plurality of resilient clips, the clips being adapted to engage with a part of the downlight can. By making the cover assembly into a clip-on fitment, a cover assembly can easily be fixed in place as and when required, and can be retro-fitted to existing downlights if required.

Preferably the resilient clips are adapted to engage with ventilation holes in the downlight can and preferably the holes are in the rear wall of the can.

In a particularly preferred embodiment the cover means comprises a dome shaped cover. By using a domed cover the ventilation holes are substantially completely protected from being obscured. Preferably bottom edges of the dome shaped cover substantially mate up with the outside perimeter of the end of the downlight can.

In a further preferred embodiment the attachment means comprises two opposing resiliency biased clips. By using opposing clips the cover assembly can be securely fixed to the downlight.

Preferably the cover means incorporates a plurality of apertures through which hot gases may escape. These apertures may be holes or slots of a variety of shapes and sizes. It is particularly advantageous if there is a substantially free flow of heated air through the ventilation cover assembly.

In an alternative preferred embodiment the cover means comprises substantially C- shaped support elements rotatably mounted with respect to each other. This is a particularly simple and cost effective arrangement, and preferably a clip is provided at the end of each leg of the C-shaped support element, the clips being adapted to engage with some part of a downlight can.

According to a second aspect of the present invention there is provided a downlight incorporating a ventilation cover assembly as described and claimed herein. The ventilation cover assembly may be an integral part of the downlight of may be a separate unit which is attached to the downlight when and if that functionality is required. Brief Description of the Drawings

Preferred embodiments of the present invention will now be described by way of example only, with reference to the accompanying drawings, wherein:-

Figure 1 shows various views of a downlight with a first embodiment of a ventilation cover assembly;

Figure 2 shows various views of a first embodiment of a ventilation cover assembly;

Figure 3 shows various views of a downlight with a second embodiment of a ventilation cover assembly;

Figure 4 shows various views of a second embodiment of a ventilation cover assembly; Figure 5 shows various views of a downlight with a third embodiment of a ventilation cover assembly;

Figure 6 shows various views of a third embodiment of a ventilation cover assembly;

Figure 7 shows various views of a downlight with a fourth embodiment of a ventilation cover assembly;

Figure 8 shows various views of a fourth embodiment of a ventilation cover assembly Description of the Preferred Embodiments

The present invention will now be described by way of example only. These are not the only ways that the invention may be put into practice, but they are the best ways currently known to the applicant. Referring to Figures 1A to 1 F inclusive, these illustrate one type of ventilation cover assembly in conjunction with a downlight or downlight assembly. The downlight assembly 10 shown in Figure 1 is relatively conventional in so far as it comprises a circular cylindrical casing 1 1 that is adapted to house a downlight lamp, such as a halogen lamp (not shown), and has an annular front flange 13 to butt up against the rim of a ceiling aperture in which the downlight is being installed. A pair of resiliency sprung mounting clips 14 project laterally from either side of the casing 1 1 and are forwardly biased to press against the inner/upper surface of the ceiling to hold the casing 1 1 in place. The circular cylindrical casing 1 1 resembles a canister with a rear end wall 15 and an open front end 12 through which the light from the lamp is projected directly or through a window.

The rear end wall 15 of the casing has a central aperture 16 through which passes a pair of power cables as fed from a terminal block (not shown) carried on a mounting arm 17. The arm 17 is bolted, riveted or otherwise mounted to the casing 1 1 substantially coplanar with, but displaced away from, the end wall 15 and projecting laterally away from the casing. In common with most fire rated downlighter casing, the casing 1 1 is provided with a plurality of ventilation apertures 18 in its rear end wall 15. The relatively large volume of the casing 1 1 and the relatively large ventilation aperture area facilitate ventilation. Any blockage of these ventilation holes will have a major impact on the functioning of the downlight. It will be understood that further or alternative ventilation holes can be provided in other sides or surfaces of the casing.

To prevent any material, such as an insulating blanket, obscuring the ventilation holes 15, a ventilation cover assembly 20 is provided that clips into position over the rear end wall of the downlight assembly. In this embodiment the ventilation cover assembly, shown in more detail in Figure 2, comprises two C-shaped spacers 21 , 24 fixed together in substantially the centre of each central leg of the "C" such that the arms of the "C" 22, 23, 25, 26 may be splayed apart. These spacers, in combination and when splayed apart, as shown in Figures 2A and 2G, provide a cover for the end of the downlight assembly through which hot gases can flow substantially unimpeded, but which prevents insulating material from coming close to or from obscuring the ventilation holes in the rear wall of the casing 1 1 .

At the end of each arm of each of the C shaped spacers is a clip 27, 28, 29, 30 designed to engage with a rim or similar feature on the rear end wall 15 of the casing 1 1 . The arms 22, 23, 25, 26 may be tensioned inwardly when clipped into the position shown in Figure 1 F and this helps to retain the ventilation cover assembly in place when in use. Thus the arms of the C-shaped spacers may be resiliency deformable. In an alternative embodiment the clips on the ends of the arms may be adapted to engage in ventilation holes near the perimeter of the rear wall of the can.

The two spacers 21 , 24 in this example are bolted together with a bolt 31 such that the spacers are rotatably mounted with respect to each other. Once in the desired orientation, the bolt may be tightened such that the spacers are substantially fixed with respect to each other.

The spacers 21 , 24 may be formed from any suitable material but a metal is preferred. In this example each spacer is formed from two components consisting of an L-shaped bracket. One leg of each L has a clip at one end whilst the other leg of the L has an elongate hole through which the fixing bolt 31 may pass. Arranging all four L-shaped brackets in the configuration shown in Figure 2, and tightening bolt 31 completes the assembly of the ventilation cover assembly, which then can simply be clipped onto the rear end wall of a downlight can.

In the above embodiment the attachment means comprises resiliency sprung clips that are adapted to engage with the top of the casing. It will be understood that the attachment means in this embodiment could equally well take the form of pins that engage with the ventilation holes on the rear wall of the casing, as in the embodiment described below. In this description the terms "downlight", "down light", "down lighter" and "down lighter" all have the same meaning and refer to a recessed lamp of the type shown in the figures. Similarly the terms "can" and "casing" have an equivalent meaning.

Referring now to Figures 3 and 4, these illustrate a further embodiment of a ventilation cover assembly. The downlight assembly 1 10, consisting of a casing 1 1 1 , an annular front flange 1 13, and mounting clips 1 14 is similar to that described above in relation to Figures 1 and 2. The ventilation cover assembly however takes a quite different form. In this embodiment the cover takes the form of a substantially domed cover 140, having a top 141 and a substantially circular sidewall 142. Both the top 141 and sidewall 142 incorporate a plurality of circular holes or apertures 143, such that the cover presents no substantial impediment to the flow of hot or heated gases flowing through the ventilation holes in the rear end wall of the casing.

Whilst the embodiment illustrated in Figures 3 and 4 shows a cover means which is narrower at one end than the other, being substantially frustoconical in shape giving a domed shape appearance, this is not essential. The cover assembly could be a substantially straight sided cylinder for example, or it could be of square or rectangular cross-section. Its function is to displace any insulation or other material away from the ventilation holes in the downlight casing, so any profile, shape and configuration which achieves this end result is intended to be covered by this disclosure. It is preferred that more than 50% of the combined area of the side and the top of the cover means is impenetrable to the type of insulation materials found in ceilings. It is particularly preferred that more than 70% of the combined area of the side and the top of the cover means is impenetrable to the type of insulation materials found in ceilings. The cover 140 also includes a further aperture 144 to accommodate a bracket 1 17. An additional aperture or additional apertures may be provided to aid the passage of a cable that passes through the top of the casing to the lamp or bulb inside the casing. This extra aperture may be in the form of a slot in the side and the top of the cover to accommodate at cable as it exits substantially vertically from the top of the casing (not shown).

The cover 140 incorporates two resilient clips 145, 146 which engage with corresponding ventilation holes in the rear end wall of the casing. These clips, which extend below the general level of the body of the cover are secured to the top of the cover 140 by bolts 147, 148 or similar fixings, oppose each other such that they combine together in their action to keep the cover assembly in place over the rear end wall of the casing of the downlight assembly. This arrangement creates a ventilation cover assembly that is both a simple and cost effective means of keeping insulating material and the like away from the ventilation holes in the rear of the casing.

Referring to Figures 5 and 6 these illustrate a third embodiment of a ventilation cover assembly. The general form of construction is similar to that described above in relation to Figures 3 and 4 and a corresponding numbering system is used. The cover assembly comprises a substantially dome-shaped cover 240 with a top 241 and side wall 242 and resilient clips 245, 246. The clips in this embodiment comprise bulbous headed clips made up of two opposing portions with a space there between. By pressing these opposing portions together the bulbous head becomes small enough that it will pass through a ventilation hole in the rear end wall of the casing. Once through the ventilation hole, the head of the clip expands such that the head of the clip will not easily pass back through the ventilation hole. The ventilation cover assembly is therefore held in place.

In a particularly preferred embodiment these clips are separate items, detachable from the main body of the cover means. This has the advantage that different sizes of clips can be provided to suit the size or sizes of ventilation holes in the end of the casing the cover assembly must engage with. By separating the clips or attachment means from the cover means a cover assembly may be made that will engage with and fix to substantially any downlight with ventilation holes located in the rear end wall. These clips, which have a headed end and a resilient fixing end, are fitted by passing them through holes in the top of the cover means. In order to maximise the flexibility of a cover assembly, a number of such holes can be formed in the top of the cover means, to correspond with the location of ventilation holes in different makes and model of downlight.

The cover incorporates slotted holes 243A, 243B rather than substantially circular holes as in the second embodiment. However, the result is that there is still free flow of hot gases through the back of the ventilation cover assembly. The shape of the apertures in the cover means is not critical and can be any size, shape or configuration, so long as they provide the necessary ventilation.

Referring to Figures 7 and 8, these illustrate a fourth embodiment of the present invention. In this embodiment the cover 240 comprises a substantially planar plate, rather than a domed shaped assembly. This plate may be any desired shape but in this example it has a substantially circular profile and perimeter such that it corresponds to the substantially circular shape of the casing 31 1. Part of the circular profile of the cover is absent, to allow for the bracket 317. The plate 240 is spaced apart from the rear wall of the casing 315 by means of spacers 345, 346 to both distance the cover from the rear of the casing and attach the cover to it. These spacers may consist of sections of hollow tube through which bolts may pass. Holes in the rear wall of the casing are positioned, spaced apart and sized to accommodate the bolts for these spacers. This simple method of fixing is both cost effective and efficient.

Once again, the attachment means or spacers are separate items, detachable from the main body of the cover means. This has the advantage that different sizes of spacers can be provided to suit the size or sizes of ventilation holes in the end of the casing the cover assembly must engage with. In order to maximise the flexibility of the cover assembly, a number of holes to accommodate the spacer means can be formed in the plate or cover means, to correspond with the location of ventilation holes in different makes and model of downlight. These various embodiments share in common the feature that a ventilation cover assembly which incorporates apertures or passageways for ventilation is located above and spaced apart and away from the ventilation holes in the rear end wall of a downlight casing. This ventilation cover assembly ensures that any insulation or similar material is kept away from the ventilation holes in the rear wall of the downlight casing.