WO1991001468A1

WO1991001468A1 - Improvements in downlights

Info

Publication number: WO1991001468A1
Application number: PCT/AU1990/000304
Authority: WO
Inventors: Kenneth David Holmes; Jagjit Singh Kaurah
Original assignee: Vyatlan Pty. Ltd.
Priority date: 1989-07-17
Filing date: 1990-07-17
Publication date: 1991-02-07

Abstract

A unitary constructed downlight of polymer material, particularly of a heat resistant plastic comprising a body portion (1) for housing a light source (not shown) and a reflector portion (2). The reflector may have an etched, knurled (4) or faceted (3) inner surface finish. The inner surface (3 and 4) is also coated with a metal to reflect light and may be further coated with a scratch resistant lacquer. Clips attach at (5) to hold the downlight in place with a flange (6) being flush with the surface structure such as the roof.

Description

IMPROVEMENTS IN- DOWNLIGH5 S

The present invention relates, ir \e al terms, to improvements in means for lighting, and relate jαore particularly, but not exclusively, to so-called downlights, being lighting means which are enjoying usage to an ever-increasing degree, in both domestic and commercial premises, by reason of their efficiency in transferring light to a given area and the mood effect attributable thereto.

Throughout the ensuing description reference will be made to so-called downligjhts, being an especially preferred embodiment of an improved means for lighting in accordance with the present invention. It must be realized, however, that such is given by way of example only, and that the invention is not to be considered to be in any way restricted to such a usage or context.

In accordance with the known art high efficiency downlight reflectors are made of a metallic material, more usually aluminium but in some situations steel, having an appropriate reflective surface afforded thereto, as for example by chrome-plating or the like. It is also known in this particular field of endeavour to provide downlights having a metallic reflector, with all other parts being constructed of steel, ceramic or even plastics materials. In accordance with yet another known arrangement there can be provided a downlight having a reflector made of a suitable metallized or non-metallized plastics material but with all other parts thereof being made of a metal or ceramic material. However, the utilisation of a non- metallized plastics material reflector has been found, in the past, to give rise to an inefficient downlight and, for this reason alone, such a configuration has not enjoyed much success commercially. Indeed, in accordance with the prior art it was only possible to produce reflectors that could withstand low temperatures, in the order of about 150 ^* C, with continuous use, unlike the arrangement of the present invention where temperatures of over 200 ^* C can be withstood. This has limited the use of metallized polymer reflectors to date.

Again in accordance with the prior art, clips were provided for installation of the overall downlight. Such clips were constructed, traditionally, of a metal material, preferably a flexible material. These clips were found to fail due to the high temperatures experienced by the downlight.

The present invention seeks to overcome the problems and disadvantages associated with the prior art by providing a form of downlight which is especially simple, and hence cheap, to manufacture, yet includes a desirable highly reflective surface for the provision of an even, diffused light or lighting effect. This effect can be achieved even in the worst possible instance of using, for example, a clear nonreflective globe.

In accordance with one aspect of the present invention, therefore, there is provided a downlight constructed principally of a plastics or polymer material, said downlight being of a unitary construction and including a reflector portion and a portion for receiving and retaining a light-source, wherein said reflector portion or luminaire is constructed of metallized plastics material.

In accordance with a preferred embodiment of the invention the reflector portion or luminaire of said downlight includes respective first inner and second outer sections, said first and second sections exhibiting different surface finishes or textures.

In order that the invention may be more clearly understood and put into practical effect there shall now be described in detail preferred embodiments of a downlight in accordance with the present invention. The ensuing description is given by way of non-limitative example only and is with reference to the accompanying drawings, wherein:

Fig. 1 is a side view, in section, of a downlight in accordance with the invention;

Fig. 2 is a perspective view, cut-away, of an especially preferred embodiment of a downlight in accordance with the invention, with the reflector portion including two sections having different surface finishes; and

Figs. 3a, 3b and 3c are respective side, end and perspective views of a fastening or installation dip for use with a downlight in accordance with the present invention.

A downlight in accordance with the present invention is preferably of a unitary construction.

The arrangement in accordance with the present invention is constructed of a suitable heat-resistant plastics or polymer material, this bearing in mind that in use the light source housed within the downlight can be expected to generate substantial amounts of heat which will have to be dissipated without resulting in damage to the downlight itself. The actual material of construction making up the downlight is not of the essence of the invention, but it is important that the material employed must be highly resistant to heat. In accordance with the present invention the surface of the downlight, more especially substantially the entire internal surface thereof, is metallized, whereby to provide an effective and efficient reflective surface for light generated within the downlight structure itself.

In accordance with a preferred embodiment of the invention the internal surface of the downlight may have dimpling or a dimpled effect created thereon, such dimpling aiding in the diffusion of light generated by an appropriate light-source to be housed within the downlight. In this regard it is an important practical requirement for the majority of lighting that a diffused effect be achieved whilst still retaining high light output or illumination effect.

In an especially preferred embodiment, as illustrated for example in FIG. 2, a downlight in accordance with the invention is made up of a first or body portion 1 intended to house a suitable light source (either releasably or in a fixed manner) in any known way. The downlight then includes a second or reflector portion 2 which acts as a reflector for light energy propagated by the light source. The second portion 2 may then be made up of first and second, respective inner and outer, sections 3 and 4 each exhibiting a different surface finish or texture. In one preferred embodiment the first, inner section 3 may be provided with a multitude of facets, whilst the second, outer section 4 may be etched or knurled for example. The purpose of such discontinuities in the surface (internal) of the reflector portion is to assist in transmission of light energy, whilst at the same time enhancing diffusion of incident light energy.

The downlight itself in accordance with the invention, constructed from a polymer or plastics material, is preferably coated with a high purity aluminium, which in turn is itself protected by a clear lacquer. The lacquer, which makes the surface virtually scratch-resistant, also acts to provide a barrier against moisture and corrosion, and can withstand temperatures up to at 320 ^* C without substantial discolouration.

A junction box for connection to a source of electrical energy is preferably provided at the top of the downlight in accordance with the invention. It should be understood, however, that the actual locating of such junction box thereof may be varied to suit more practical requirements, as for example location of the downlight in a given work or operating space.

The actual installation of a downlight in accordance with the present invention may be achieved in any known manner. To assist therein, in an especially preferred embodiment a downlight has incorporated therewith a plurality of installation clips (FIGS. 3a, 3b and 3c) which function to fix the downlight in place relative to a rdof, wall or the like surface. The clips in accordance with the present invention will also be constructed of a high-temperature resistant plastics material, thereby reducing, if not eliminating altogether, the likelihood of failure thereof. Such clips may be releasably affixed relative to the downlight, utilizing the apertured fixtures 5 as provided integrally with the downlight. The reflector portion 2 further includes a flange 6 or the like end projection, said flange 6 serving as a limit stop means for installation of the overall downlight within a wall or roof of a building or the like structure.

The overall downlight itself is preferably provided in a fully assembled condition, including a lamp holder of any suitable and known type (to receive and retain a globe of any suitable type), and an enclosed junction box.

The arrangement in accordance with the present invention differs from the known art in a number of ways which have been found to give rise to important practical and economic effects and advantages, as explained hereinafter in more detail.

First of all the arrangement in accordance with the present invention, by being preferably constructed of a high temperature heat- resistant polymer material which is subsequently metallized, when compared with the prior art metallic structures lends itself to simpler and cheaper production, whilst at the same time resulting in an overall product which is exceedingly superior, meaning having a better reflective surface, thereby transferring a higher percentage of the available light, to the required area lower energy operating requirements, providing a more uniform light distribution and easier installation due to its being a fully pre- assembled unit.

Secondly, the downlight has the overall flexibility and toughness to take rough handling, as will more often than not be the case during installation. The prior art metal downlights are prone to unwanted denting, with its resultant loss of effectiveness and aesthetic appeal.

The downlight in accordance with the present invention has been found to substantially limit glare and hence to provide a soft, even distribution of light. In numerical terms, and by way of example only, with the prior art arrangements manufacturers have attempted to achieve a light output (as a proportion of light generated) of 70% with even that figure rarely having been attained in practice. It has been found, however, that a downlight in accordance with the present invention will exhibit a light output value as high as 80% of incident or generated light. The improvements thus achieved, in terms not only of cost effectiveness but also of the degree of illumination achieved, should be self-evident. In purely practical terms, a greater iUuminating effect can be achieved with a lesser power input - an obvious saving in energy consumption.

The arrangement in accordance with the present invention exhibits yet another extremely important advantage over the prior art all- metal downlights, in terms of flexibility. With the known downlights of metal, it was difficult and accordingly expensive to achieve or manufacture such lights in anything other than what might be termed basic reflective shapes. The use of plastics or polymers allow for the creation of downlights in effect in an infinite variety of reflective shapes, yet in an extremely cost-effective manner.

As an extension of the above the very structure of the downlight in accordance with the present invention, especially when a screen of a suitable type is incorporated therewith, would serve to restrict entry into a building or work-space of large insects, flies, spiders and the like.

It should be understood that the aforegoing description refers merely to preferred embodiments of the invention and that variations and modifications will be possible thereto without departing from the spirit and scope of the invention, the ambit of which is to be determined from the following claims.

Claims

The claims defining the invention are as follows:

1. A downlight, being of unitary construction and constructed principally of a polymer material, said downlight including a reflector portion and a portion for receiving and retaining a light source, wherein said reflector portion has the internal surface thereof coated with a metal or the like material.

2. The downlight as claimed in claim 1, wherein said reflector portion includes respective first and second inner and outer sections, said sections exhibiting different surface finishes and textures.

3. The downlight as claimed in claim 2, wherein said inner section of said reflector portion is provided with a multitude of facets, and wherein said second portion is knurled or etched.

4. The downlight as claimed in any one of the preceding claims, wherein the internal surface of said reflector portion is coated with aluminium.

5. The downlight as claimed in any one of the preceding claims, wherein said metal coated surface of said reflector portion is further coated with a lacquer whereby to impart substantial scratch resistance thereto.

6. The downlight as claimed in any one of the preceding claims, having a junction box associated therewith allowing for connection of said light source to a power supply.

7. The downlight as claimed in claim 6, wherein said junction box is releasably connected to said light source receiving portion.

8. The downlight as claimed in any one of the preceding claims, having associated therewith means allowing for installation within a building space, said means including a plurality of clips.

9. The downlight as claimed in claim 8, wherein said clips are constructed of a plastics or polymer material.