AU2011101089A4 - Downlight Fixture - Google Patents

Abstract

Abstract A downlight fixture comprising a mounting ring configured to mount the downlight fixture in a hole. The fixture including a means for supporting a lamp socket above the mounting ring and a lamp housing. Wherein the mounting ring comprises means for frictionally holding the lamp housing in position, the means being located on the inner face of the mounting ring. Figure 1 14 105, 106 42b 102 42b. 42a 24 17 18 16

Description

DOWNLIGHT FIXTURE Field of Invention The invention relates to downlights. More particularly, the invention relates to a downlight fixture enabling a downlight to be recessed into, for example, a ceiling and an improvement in holding a lamp housing or reflector in position. Background to the Invention Downlights are ceiling-mounted lighting fixtures that can be recessed into a ceiling cavity and shine downwards into a room. Downlights have become widespread because they are a stylish source of effective lighting. They are also unobtrusive because they do not protrude into a room to the extent of other types of light fixture. Downlights are used in many different situations, including residential and commercial buildings. They can be installed in both new and existing constructions by mounting in a ceiling panel or other ceiling installation. Conventional downlight fixtures include a mounting ring for mounting the downlight in a hole in a ceiling and a structure that supports a lamp socket above the centre of the mounting ring. Downlight fixtures often also include a lamp housing (sometimes known as a reflector) with a reflective inner surface to channel light downwards into a room. In many downlight fixtures, the lamp housing is held in place, at least in part, by a bezel structure in the mounting ring. Often, the mounting ring includes a detachable ring plate which forms the ring part of the bezel structure. The lower surface of the ring plate is usually intended to be the only part of the light fitting that is visible from the room when installed. The ring plate may be detachable so that the lamp housing can be removed from the fixture. It may be necessary to remove the lamp housing for maintenance purposes or, for example, to give access to a mechanism holding the downlight fixture in place in the ceiling so that the fixture can be removed. However, if only the ring plate holds the lamp housing in place, the lamp housing is prone to falling out when the ring plate is removed, which is undesirable as it might fall onto the person who has removed the ring plate. 1 In one known downlight fixture, the lamp housing is held in place by three springs or resilient bars attached to the lamp socket supporting structure. The springs engage with the inside rim of the top of the lamp housing, each exerting an outwards force on the lamp housing so that together the springs hold the lamp housing in position. A downlight fixture having such springs may not require a removable ring plate to hold the lamp housing in place. However, without a ring plate the bottom rim of the lamp housing will be visible from below, which may not be aesthetically desirable. In addition, manufacturing a downlight fixture with springs as have been described requires the manufacture and supply of springs and also requires the fixture to include fittings for the springs. These requirements involve a reasonable amount of cost, time and complexity, all of which are preferably avoided. It is an object of the invention to overcome at least some of the aforementioned disadvantages of known downlight fixtures and provide an improved downlight fixture. Alternatively, it is an object of the invention to at least provide the public with a useful choice. Summary of the Invention According to a first aspect of the invention, there is provided a downlight fixture comprising: a mounting ring configured to mount the downlight fixture in a hole; means for supporting a lamp socket above the mounting ring; and a lamp housing, wherein the mounting ring comprises means for frictionally holding the lamp housing in position, the means being located on the inner face of the mounting ring. Preferably, the means for frictionally holding the lamp housing in position comprises one or more lugs on its inner face. Preferably, each lug is resiliently displaceable by the lamp housing such that the lamp housing is held in place by friction. Preferably, each lug comprises a portion extending inwards from the inner face of the mounting ring. In one embodiment of the invention, each lug comprises a downwardly oriented elongate portion substantially co-planar with the inner face of the mounting ring and, optionally, an inward projection on its bottom edge. 2 Preferably, the mounting ring comprises a notched inner edge to its bottom face, the notch being configured to receive a flanged lower edge of the lamp housing. Preferably, the downlight fixture further comprises a ring plate detachably mounted underneath the mounting ring such that the lamp housing is able to be removed from the downlight fixture when the ring plate is detached. More preferably, the ring plate obscures the bottom edge of the lamp housing from view when the ring plate is mounted underneath the mounting ring. Preferably, the mounting ring defines an outer rim configured to mount the downlight fixture in the hole. Preferably, the ring plate comprises projections on an upper side adapted to engage with the mounting ring. More preferably, the projections are positioned such that, when the ring plate is attached to the mounting ring, the projections are substantially inside the rim of the mounting ring. Preferably, the mounting ring comprises recesses on a lower side for receiving the projections of the ring plate. Preferably, the ring plate is adapted to attach to the mounting ring by rotational movement of the ring plate relative to the mounting ring causing the projections of the ring plate to engage with lips on the mounting ring. Preferably, the lips are positioned on a side wall of the recesses. In a preferred embodiment, the flanged lower edge of the lamp housing is mounted in a bezel structure formed by the mounting ring and ring plate. The bezel structure preferably comprises a groove between the mounting ring and ring plate, the groove being formed at least in part by the notched inner edge of the mounting ring. Preferably, the ring plate comprises a circumferential ridge on an outer portion of its upper side. In a preferred embodiment of the invention, the downlight fixture comprises at least two ring plate projections and corresponding mounting ring recesses. In a more preferred embodiment, 3 the downlight fixture comprises three ring plate projections and corresponding mounting ring recesses. Preferably, the mounting ring comprises one or more flange portions on a lower side. Preferably, the downlight fixture comprises biasing means for preventing the ring plate accidentally rotating relative to the mounting ring. More preferably, the biasing means comprises a notch and at least one corresponding groove. The notch and corresponding groove may be positioned on the upper side of the ring plate and on a lower side of a flange of the mounting ring respectively, or vice versa. Further aspects of the invention, which should be considered in all its novel aspects, will become apparent to those skilled in the art upon reading of the following description which provides at least one example of a practical application of the invention. Brief Description of the Drawings One or more embodiments of the invention will be described below by way of example only, and without intending to be limiting, with reference to the following drawings, in which: Figure 1 is an isometric, part-exploded view illustration of a downlight fixture according to an embodiment of the invention; Figure 2 is an isometric view illustration of the mounting ring shown in Figure 1; Figure 3 is another isometric view illustration of the mounting ring shown in Figure 1; Figure 4 is a top view illustration of the mounting ring and ring plate shown in Figure 1; and Figure 5 is an isometric view illustration of the lamp housing shown in Figure 1. 4 Detailed Description of Preferred Embodiments of the Invention In the following description, the invention will be described with reference to its use as a downlight in a ceiling. This is one common way the invention is expected to be used but it should be understood that this is not limiting to the invention. The "downlight" fixture that is the subject of the invention may be used in any situation, for example, it may be mounted in a wall, floor or other building structure. Reference to relative positional terms such as "above", "under" or the like when used in this specification should be understood to refer to the downlight fixture in a ceiling-mounted, orientation and therefore are not limiting to the invention if the fixture is used in a different situation. Figure 1 is an isometric, part-exploded view illustration of a downlight fixture 10 according to an embodiment of the invention. Downlight fixture 10 comprises a mounting ring 11 configured to be inserted into a hole in a ceiling or other building structure to mount the downlight fixture. The hole preferably has substantially the same diameter as a rim 12 of mounting ring 11 such that the downlight fixture can be friction fitted in the hole. Mounting ring 11 may comprise a flange 13 on an outer edge. When mounted in a hole, flange 13 abuts the surface of one side of the building structure in which the hole is made. For example, flange 13 abuts the downward facing surface of the ceiling. Flange 13 limits the extent to which the downlight fixture can be inserted into the ceiling. The flange prevents the upward movement of the downlight in the hole over time, for example caused by vibrations. Mounting ring 11 may be configured to receive a ring plate 21, shown in Figure 1 as disconnected from mounting ring 11. Ring plate 21 provides a facia to the downlight fixture as seen from below. In the embodiment shown, the ring plate connects to mounting ring 11 at slots 17. Ring plate 21 is adapted to attach to mounting ring 11. Ring plate 21 comprises three projections 15 on its upper side. Projections 15 each comprise a lug 19. Projections 15 are adapted to engage with projection receiving portions 16 of mounting ring 11. In the embodiment shown, projection receiving portions 16 are recessed into the lower side of mounting ring 11. Projection receiving portions 16 comprise a projection receiving channel 17 and lip 18. To attach ring plate 21 to mounting ring 11, the projections are inserted into channel 17 and rotational 5 movement of ring plate 21 relative to mounting ring 11 causes lugs 19 to engage with lips 18. Lips 18 may be positioned on a side wall of the recesses. A lamp 14 is supported above the mounting ring by appropriate means. In preferred embodiments, the lamp is supported approximately centrally above the mounting ring. In the embodiment shown in Figure 1, lamp 14 is an LED lamp, for example of the sort consisting of an array of individual LEDs. Lamp 14 is supported by lamp housing 15. Figure 5 is an isometric view illustration of lamp housing 15 shown in Figure 1. Lamp housing 15 may have a reflective interior surface to channel light downwards into the room, as is known in the art. For this reason, lamp housing 15 is commonly referred to as a reflector. However, the invention includes embodiments in which the interior surface of the lamp housing is not reflective. In other embodiments of the invention, a lamp socket is supported above the mounting ring. The lamp socket may be configured to receive other types of lamps, e.g. screw bulbs, bayonet bulbs, spotlights, halogen lights or any other light emitting device. In one form of the invention, the downlight fixture comprises one or more frame members connected to the mounting ring and configured to support the lamp socket in position. Such frame members may be, for example, similar to frame member 41 illustrated in Figure 1. In the embodiment shown in Figure 1, frame member 41 does not support lamp 14 in position and instead the means for supporting the lamp comprises lamp housing 15.. However in alternative embodiments the downlight fixture may comprise two frame members of this type on opposing sides of the mounting ring and between them they support a lamp socket. Such an arrangement is well known in the art and is therefore not explained more fully herein. Referring again to the embodiment of the invention illustrated in Figure 1, downlight fixture 10 comprises one frame member 41 connected to mounting ring 11 at slot 42a. A biasing member in the form of double helical torsion spring 101 is connected to frame member 41 by means of pin 102, which passes through the two coils of spring 101 and holes on either side of frame member 41. Optionally, downlight fixture 10 also comprises clip member 103, which is hinged to frame member 41, for example by means of hooks on clip member 103 which engage with pin 102. Spring 101 is adjustable between a first, biasing configuration and a second, non-biasing configuration. Figure 1 illustrates spring 101 in the first, biasing configuration. In this configuration, arms 104 of spring 101 extend upwards away from the mounting ring 11 and are held in fixed relation to frame member 41 by projections 105, which optionally has lipped tips 6 106. Spring 101 is configured such that, when placed in the configuration illustrated in Figure 1, the spring is held in tension. Therefore central arm 107, which extends downwards towards mounting ring 11, is biased rotationally downwards and pushes clip member 103 downwards. In use, clip member 103 is sufficiently long that, when downlight fixture 10 is mounted in a ceiling hole, the upper surface of the ceiling causes rotational displacement of clip member 103 and hence arm 107 upwards. As a result, arm 107 is held under tension and spring 101 exerts a force having a downwards component in the direction of the upper surface of the ceiling. Since flange 13 prevents the downlight fixture moving up through the hole, the downlight fixture is held securely in position. In embodiments in which clip member 103 is absent, arm 107 is sufficiently long such that it is rotationally displaced when the downlight fixture is mounted in the ceiling. In the first configuration thus far described, downlight fixture 10 is difficult to install and remove from the ceiling. Pushing upwards on clip member 103 requires an increasingly large force to displace the clip member. To insert the downlight fixture into the ceiling hole the clip member needs to be pushed far upwards, which is difficult. Likewise, to remove the downlight fixture when the spring is in the first configuration requires downwards pull on mounting ring 11, which causes clip member 103 to move upwards. However, in doing so, the torsion in spring 101 again increases and it becomes increasingly difficult to pull mounting ring 11. Continued pulling of the mounting ring may damage the ceiling. To make the downlight fixture easier to both install and remove from the ceiling hole, spring 101 can be adjusted to a non-biasing configuration. In the non-biasing configuration, arms 104 are pushed off projections 105 such that the arms are no longer held in position by the projections. Since in the first configuration, spring 101 is in tension, moving the arms off projections 105 causes the arms to move behind the projections and the tension in spring 101 to be released. As a result, clip member 103 is able to be moved upwards with little difficulty because spring 101 is no longer inhibited and can rotate freely around pin 102. When spring 101 is in the non-biasing configuration, downlight fixture 10 can be easily installed in the ceiling hole by pushing clip member 103 upwards, pushing the downlight fixture into the hole such that the mounting ring is friction fitted in the hole and putting spring 101 in the biasing configuration by moving arms 104 onto projections 105. A person can move arms 104 onto 7 projections 105 by reaching up through mounting ring 11 with their hands, using a screw driver or any other means. Furthermore, downlight fixture 10 can be removed from the ceiling hole by removing lamp housing 15 from the downlight fixture by pulling it downwards and then moving arms 104 off projections 105 before pulling down on mounting ring 11, resulting in clip member 103 being pushed upwards so that it can easily pass through the hole without damage to the hole or the downlight fixture. In a preferred embodiment of the invention, a second frame member is connected to mounting ring 11 at slot 42b, diametrically opposite slot 42a. In this embodiment, a second biasing member and a second clip member are also provided. This second fitting further secures the downlight fixture in place. The downlight fixture mechanism described above is easy to assemble because spring 101 can be connected onto frame member 41 using pin 102 while the spring is not under tension. Only after the mechanism has been assembled, and the downlight fixture installed into the ceiling, are the arms 104 moved onto projections 105, thus giving the spring tension. The invention therefore provides easier assembly compared to some prior arrangements, in which parts are assembled under tension. Lamp housing 15 comprises a body in the shape of a hollow cylinder having tapering sides. The following description explains, with reference to Figures 2 and 3, how lamp housing 15 is held in place inside mounting ring 11 in preferred embodiments of the invention. Figures 2 and 3 are isometric view illustrations of the mounting ring 11 shown in Figure 1. Mounting ring 11 comprises means for frictionally holding lamp housing 15 in place when positioned inside mounting ring 11. In the preferred embodiment shown in the figures, the means for frictionally holding lamp housing 15 in place comprises one or more lugs 31 on the inner side of mounting ring 11. Lugs 31 are preferably resiliently deformable such that, when lamp housing 15 is positioned in the mounting ring, the lugs are pushed outwards and therefore impart an inwards force on lamp housing 15, holding it in position. Each lug extends inwards from the inner face of mounting ring 11 such that it is deformed when the lamp housing is in position. In the preferred embodiment shown in Figures 2 and 3, each lug 31 comprises a downwardly oriented elongate portion 8 adjacent a recess or cavity in mounting ring 11. The elongate portion extends slightly inwards from the plane of the inner face of mounting ring 11. In an alternative embodiment, the elongate portion is substantially co-planar with the inner face of the mounting ring and comprises an inward projection on its bottom edge. Means for holding lamp housing 15 in place such as lugs 31 can be integrally formed as part of mounting ring 11. For example, in preferred embodiments, mounting ring 11 is made of a plastics material and can be injection moulded as a unitary construction without the use of sliding wedges. As a result, mounting ring 11 is cheap, easy and quick to manufacture. In the preferred form of the invention shown in Figures 1 to 4, mounting ring 11 comprises three lugs 31. Other embodiments comprise other numbers of lugs. Ring plate 21 may be used for aesthetic reasons: for example, it obscures the bottom edge of lamp housing 15 from view, which may be desirable depending on one's tastes. Ring plate 21 may also help keep lamp housing in position, as will now be described. When ring plate 21 is mounted on mounting ring 11 a bezel structure may be formed. The bezel structure comprises a groove formed between mounting ring 11 and ring plate 21. As shown in Figure 5, lamp housing 15 has a slightly flanged lower edge 51 which is positioned inside this groove, thereby assisting in holding the lamp housing in position. The aforementioned groove is preferably formed from a notch 32 on the lower inner edge of mounting ring 11. In an alternative embodiment, the bezel groove may be formed by a groove on the upper inner side of the ring plate either alone or in combination with a notch on the mounting ring. The detachment of ring plate 21 from mounting ring 11 allows the lamp housing to be removed by sliding downwards. This is desirable, for example, to allow maintenance to be performed on the light fixture from the room below or, in the case of fixtures of the type which have a mounting mechanism only easily accessible when the lamp housing is removed, to allow the fixture to be removed from the ceiling. The lamp housing is preferably not able to be removed from the downlight fixture while ring plate 21 is in position. Even when ring plate 21 is moved, lugs 31 hold lamp housing 15 in position, meaning the lamp housing will not fall on a person who removes ring plate 21. A circumferential ridge 23 on an outer portion of the upper side of ring plate 21 covers the side of flange 13 of the mounting ring such that ridge 23 substantially abuts the ceiling when ring 9 plate 21 is attached to the mounting ring and hence covers the sides of flange 13 such that flange 13 is not visible from the room. Figure 4 is a top view illustration of the mounting ring 11 and ring plate 21 shown in Figure 1 in the configuration when ring plate 21 is attached to mounting ring 11. In this configuration, projections 15 are positioned substantially inside rim 12 of mounting ring 11. This arrangement improves on known fixtures because ring plate 21 may be constructed to have a thickness that is less than the height of projections 15 while enabling only ring plate 21 to be visible from the room and the ring plate to substantially abut the ceiling so that the downlight fixture extends below the level of the ceiling only to the extent of the thickness of ring plate 21. Projections 15 engage with mounting ring 11 inside rim 12 and inside the rim of the hole in the ceiling, therefore may extend upwards into the hole. This allows projections 15 to be sufficiently long as to be able to attach the ring plate to the mounting ring without adversely affecting the thickness of the ring plate. The downlight fixture shown in Figures 1 to 4 preferably comprises biasing means to prevent accidental rotational movement of ring plate 21 relative to mounting ring 11 when the two components are attached together. In the embodiment shown, the biasing means comprises a notch 24 on the upper side of the ring plate and one or more grooves or holes 22 on flange 13. Notch 24 and one or more grooves 22 are positioned such that, when projections 15 are fully rotated into projection receiving portions 16, notch 24 engages with one of the grooves. Only a small force is required to remove notch 24 from the corresponding groove so that a human can easily remove ring plate 21 but the ring plate cannot be otherwise removed, for example as a result of vibrations. Including three grooves 22 to receive only one notch 24 means that the notch will engage with one of the grooves irrespective of which orientation the ring plate is in when it is attached to the mounting ring. In another embodiment, a notch may be disposed on the underside of one of the flanges of the mounting ring, with corresponding grooves on the upper side of the ring plate, i.e. the reverse arrangement to that described above in relation to the embodiment shown in the figures. Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like, are to be construed in an inclusive sense as 10 opposed to an exclusive or exhaustive sense, that is to say, in the sense of "including, but not limited to". The entire disclosures of all applications, patents and publications cited above and below, if any, are herein incorporated by reference. Reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that that prior art forms part of the common general knowledge in the field of endeavour in any country in the world. The invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features. Where in the foregoing description reference has been made to integers or components having known equivalents thereof, those integers are herein incorporated as if individually set forth. It should be noted that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the invention and without diminishing its attendant advantages. It is therefore intended that such changes and modifications be included within the present invention. 11

Claims (23)

1. A downlight fixture comprising: a mounting ring configured to mount the downlight fixture in a hole; means for supporting a lamp socket above the mounting ring; and a lamp housing, wherein the mounting ring comprises means for frictionally holding the lamp housing in position, the means being located on the inner face of the mounting ring.

2. A downlight fixture as claimed in claim 1, wherein the means for frictionally holding the lamp housing in position comprises one or more lugs on its inner face.

3. A downlight fixture as claimed in claim 2, wherein each lug is resiliently displaceable by the lamp housing such that the lamp housing is held in place by friction.

4. A downlight fixture as claimed in claim 3, wherein each lug comprises a portion extending inwards from the inner face of the mounting ring.

5. A downlight fixture as claimed in claim 4, wherein each lug comprises a downwardly oriented elongate portion substantially co-planar with the inner face of the mounting ring.

6. A downlight fixture as claimed in claim 5, wherein each lug comprises an inward projection on its bottom edge.

7. A downlight fixture as claimed in any one of claims 1-6, wherein the mounting ring comprises a notched inner edge to its bottom face, the notch being configured to receive a flanged lower edge of the lamp housing.

8. A downlight fixture as claimed in any one of claims 1-7, wherein the downlight fixture further comprises a ring plate detachably mounted underneath the mounting ring such that the lamp housing is able to be removed from the downlight fixture when the ring plate is detached. 12

9. A downlight fixture as claimed in claim 8, wherein the ring plate obscures the bottom edge of the lamp housing from view when the ring plate is mounted underneath the mounting ring.

10. A downlight fixture as claimed in any one of claims 1-9, wherein the mounting ring defines an outer rim configured to mount the downlight fixture in the hole.

11. A downlight fixture as claimed in any one of claims 8-10, wherein the ring plate comprises projections on an upper side adapted to engage with the mounting ring.

12. A downlight fixture as claimed in claim 11, wherein the projections are positioned such that, when the ring plate is attached to the mounting ring, the projections are substantially inside the rim of the mounting ring.

13. A downlight fixture as claimed in any one of claims 11-12, wherein the mounting ring comprises recesses on a lower side for receiving the projections of the ring plate.

14. A downlight fixture as claimed in any one of claims 11-13, wherein the ring plate is adapted to attach to the mounting ring by rotational movement of the ring plate relative to the mounting ring causing the projections of the ring plate to engage with lips on the mounting ring.

15. A downlight fixture as claimed in claim 14, wherein the lips are positioned on a side wall of the recesses.

16. A downlight fixture as claimed in any one of claims 8-15, wherein the flanged lower edge of the lamp housing is mounted in a bezel structure formed by the mounting ring and ring plate.

17. A downlight fixture as claimed in claim 16, wherein the bezel structure comprises a groove between the mounting ring and ring plate, the groove being formed at least in part by the notched inner edge of the mounting ring.

18. A downlight fixture as claimed in any one of claims 8-17, wherein the ring plate comprises a circumferential ridge on an outer portion of its upper side. 13

19. A downlight fixture as claimed in any one of claims 11-18, wherein the downlight fixture comprises at least two ring plate projections and corresponding mounting ring recesses.

20. A downlight fixture as claimed in claim 19, wherein the downlight fixture comprises three ring plate projections and corresponding mounting ring recesses.

21. A downlight fixture as claimed in any one of claims 1-20, wherein the mounting ring comprises one or more flange portions on a lower side.

22. A downlight fixture as claimed in any one of claims 14-20 or claim 21 when dependent on claim 14, wherein the downlight fixture comprises biasing means for preventing the ring plate accidentally rotating relative to the mounting ring.

23. A downlight fixture as claimed in claim 22, wherein the biasing means comprises a notch and at least one corresponding groove. 14