This invention relates to a combination of a lamp assembly and a mounting member.
The invention has been devised in relation to the mounting of lamp assemblies each comprising a lamp and a reflector therefor, such a lamp assembly being hereafter referred to as a lamp assembly of the kind specified, and in particular the invention has been devised in relation to a lamp assembly of the kind specified in which the lamp is a miniature low voltage metal filament halogen lamp. Such a lamp assembly is commonly referred to as a dichroic lamp because the reflector reflects light but does not reflect heal from the lamp. It is to be appreciated, however, that the invention would be equally applicable to lamp assemblies of the kind specified wherein the lamp is of type other than a miniature low voltage metal filament halogen lamp, for example a lamp in which the light source is an electrical discharge rather than a heated filament.
Light fittings for receiving dichroic lamps are known wherein the lamp is held in a lamp-receiving part by engagement between the lamp-receiving part and a flange portion which characteristically is provided at the front periphery of the dichroic reflector. For example, the flange might abut an annular seating in the lamp-receiving part and a spring device such as a circlip engage the flange and lamp-receiving part to retain them in engagement. Alternatively, a spring device might engage the reflector adjacent the flange to retain it. It is then necessary to provide for co-operation between the lamp-receiving part and the remainder of the light fitting and in many fittings such engagement must accommodate tilting and/or swivelling of the lamp-receiving part relative to the rest of the fitting in order to enable the light emitted from the lamp to be directed as required. This renders the light fitting complex and expensive.
French patent applications 2,617,946 and 2,562,638 each disclose a combination of a lamp assembly and a mounting member, the lamp assembly comprising a lamp and a reflector, the mounting member having a portion with which the lamp assembly is resiliently held, and a separate portion adapted to resiliently engage a light fitting into which the lamp assembly is to be mounted. In these documents, the "light fitting" comprises an aperture which has been formed in a ceiling panel to receive the lamp assembly.
According to a first aspect of the invention there is provided a combination of a lamp assembly and a mounting member as defined in the preceding paragraph, characterised by a heat shield member which is also held by the mounting member. The provision of a heat shield member improves the fire rating of the lamp assembly when mounted in a fitting.
Preferably the mounting member is a one-piece member of resilient material. Conveniently it may be of metal, formed to the required shape by appropriate pressing and bending operations. To give it the necessary resilience it may be of spring steel.
Preferably the portion of the mounting member with which the lamp assembly is resiliently held comprises opposed formations extending towards one another and engageable with oppositely outwardly facing grooves or recesses on a rear portion of the lamp assembly. Such formations of the mounting member may be engaged with the lamp assembly by displacing them away from one another against the resilience of the mounting member and then, when the lamp assembly is appropriately positioned, allowing them to move towards one another into engagement therewith.
According to a further aspect of the invention there is provided a light fitting fitted with a combination as herein defined, the mounting member holding the lamp assembly and the heat shield member, and engaging the light fitting.
The light fitting may have a pair of appropriately configured opposed recesses in which formations at the free ends of arms of the mounting member are engaged, in which case the lamp assembly is capable only of pivotal movement relative to the light fitting about said axis.
Alternatively, the light fitting may be provided with an inwardly facing annular recess with which the formations are engaged, in which case the lamp assembly and mounting member are able to move rotationally relative to the light fitting with said formations of the mounting member moving around said recess. Such movement is additional to the pivotal movement, enabling the lamp assembly to undergo universal pivotal movement to face in any required direction relative to the light fitting (subject of course to limitations on such movement imposed by the dimensions of the light fitting, the ability to have electrical connections to the lamp assembly made by suitable cables, and so on).
According to a another aspect of the invention there is provided a suspended ceiling structure having a light fitting as herein defined combined with a retaining member fitted into a panel of a ceiling, in which limbs of the retaining member rest on support members for the panel.
Preferred features of each aspect of the invention are the subject of the dependent claims.
These and other features of invention will now be described by way of example with reference to the accompanying drawings, of which:-
Referring firstly to Figures 1 and 2 of the drawings, these show a light fitting which in plan view is of circular configuration and comprises a flange 10 which forms the front of the fitting, visible when it is installed as described hereafter, and a rearwardly extending body portion indicated generally at 11. The body portion 11 adjacent the flange 10 has a portion 12 which affords an annular recess whose base 13 may be of generally part spherical configuration or of shallower curvature. Behind the portion 12 the body 11 of the light fitting has a generally cylindrical portion 14 of reduced diameter compared with that of the base 13 of the recess portion 12.
The flange 10 on the light fitting enables it to be mounted in an aperture in a panel 41 such as, for example, a panel in a suspended ceiling. The flange 10 abuts the front face of such panel, with the fitting being retained to the panel by a pair of spring clips 42 engaging the portion 14 of the light fitting body and pressing against the rear face of the panel 41.
The light fitting receives a lamp and reflector assembly indicated generally at 15 and which is of the type usually referred to as a dichroic lamp. It comprises a reflector 16 which may be of parabolic or generally parabolic form to produce a beam of light, which light emerges through a transparent screen or lens 17. Within the reflector there is supported a low voltage metal filament-halogen lamp and electrical conductors leading to such lamp extend through a rear portion 18 of the lamp assembly 15, Such electrical conductors terminate in connection pins indicated at 19 and electrical connection with such pins is established by way of a ceramic connector block 20. Flexible electrical conductors lead to the connector block 20 by way of electrical and heat insulating sleeves 21 behind the connector block.
The lamp assembly 15 is supported in the light fitting by a mounting member whose principal constructional features are shown in Figures 7 to 9 (although the mounting member shown in Figures 7 to 9 is actually that used in the light fittings shown in Figures 3 to 6; its dimensions differ slightly from that used in Figures 1 and 2). The mounting member, indicated generally at 22 in Figures 1 and 2 is a one-piece component made of a resilient material such as spring steel by appropriate stamping, pressing, folding, etc operations. It comprises a body portion 23 with two spaced wall portions 24. At the front end of the wall portions 24, there are oppositely inwardly extending folded formations 25 from which respective arms 26 extend forwardly and outwardly. Rearwardly of the wall portions 24 there are base portions 27 which extend towards one another, and these are joined by a rearwardly extending U-shaped portion 28. Approximately mid-way between the formations 25 and the base portions 27 the walls 24 have relatively small opposed inwardly extending formations 29.
Adjacent the ends of the arms 26 they have oppositely outwardly extending pivot formations 30. These formations, which may as illustrated be pressed into the arms 26 or possibly alternatively be provided by additional elements secured thereto, are part-circular in configuration and have slightly domed base portions as indicated at 31 to substantially conform to the curvature of the base 13 of the annular recess portion 12 of the light fitting. The free ends of the arms 26 beyond the formations 30 have tabs 32.
The body portion 23 of the mounting member holds the lamp assembly 15. The formations 25 of the mounding member resiliently engage oppositely facing recess formations 33 in the rear portion 18 of the lamp assembly adjacent the reflector 16. The ceramic connector block 20 is held in the body portion 23 by the formations 29 therein, abutting the base portions 27. The connector sleeves 21 lie within the U-shaped portion 28 of the mounting member. The formations 30 of the mounting member engage the base 13 of the annular recess portion 12 of the light fitting, and the engagement is such that the mounting member and lamp assembly held thereby is able to pivot about a transverse axis extending between the formations 30. Such axis is indicated at 34 in Figure 7. The formations 30 are also able to move rotationally around the annular recessed part 12 of the light fitting, so that within limits (defined by contact between the lamp assembly and the rear part 14 of the light fitting) universal movement of the lamp assembly relative to the light fitting is possible.
The portion 28 of the mounting member prevents contact of any potentially flammable material that might lie behind the light fitting with hot parts of the lamp assembly and its associated components.
Referring now to Figures 3, 4 and 5 of the drawings, these show a further embodiment in accordance with the invention whose principal features are the same as above described in relation to Figures 1 and 2. In Figures 3, 4 and 5, however, there is additionally provided a somewhat cup-shaped heat shield member 36. The heat shield member 36 is conveniently a metal pressing , and has a front rim portion 37 which terminates adjacent the forward-most part of the reflector of the lamp assembly, and a rear base portion 38 which is held by the mounting member in the region of its formations 35. The body portion 11 of the light fitting is the same as above described but because of the presence of the heat shield member 36 the lamp assembly is curried relative to the light fitting at a position wherein the lamp assembly protrudes slightly forwardly of the flange 10 of the light fitting. The rear of the heat shield 36 adjacent the base portion thereof engages the light fitting adjacent the portion 14 of the latter, to provide a frictional resistance to movement of the lamp assembly relative to the light fitting. The engagement of formations 30 with the annular recess in the light fitting is such that the lamp assembly is urged rearwardly so that such engagement occurs. This provision may be advantageous in, for example, environments where there is vibration. The rear of the heat shield may be non-smooth, to improve the ability of the lamp assembly to retain a set position.
The embodiment shown in Figures 3, 4 and 5 of the drawings further is distinguished from that of Figures 1 and 2 in that the mounting member does not have tabs 32. Such tabs could be provided as in Figures 1 and 2 to enable the mounting member to be squeezed by the fingers to displace its formations 30 towards one another to enable it to be fitted into and removed from the light fitting, but in practice such removal and fitting is possible by appropriately applying pressure to the lamp assembly if the tabs are not present.
The heat shield 36 prevents temperatures measurable behind the light fitting from exceeding a predetermined value, enabling the light fitting to be used in certain environments where such requirements exist.
Referring now to Figure 6 of the drawings, this shows a further embodiment of light fitting in accordance with the invention, whose principal features are the same as those shown in Figures 3 to 5, but with the difference that the light fitting, instead of having a flange 10, has a relatively small annular lip 40. This enables mounting of a number of such light fittings in close proximity to one another in a luminaire.
Referring now to Figures 10 and 11 of the drawings, these show a further embodiment of light fitting which, as for the fittings previously described, is circular in plan view. It comprises a frontal flange 110 from which a body portion 111 extends rearwardly, the body portion 111 affording an annular recess 112 with a base 113. Behind the portion 112, the body 111 has a portion 109 which extends inwardly followed by an annular rearwardly and outwardly extending portion 108 which defines a radially outwardly facing annular groove 107. The groove 107 provides for mounting of the light fitting in, for example, a panel in a suspended ceiling in the manner described hereafter.
The light fitting receives a dichroic lamp assembly indicated generally at 115. The lamp assembly 115 is supported in the light fitting by a mounting member 122 whose principal features of its configuration are as above described with reference to Figures 7-9 of the drawings. Thus the mounting member has forwardly and outwardly oppositely extending arms 126 provided at its ends with respective formations 130 (without the tabs 32 shown in Figures 7-9). The mounting member 122 further holds the lamp assembly 115, and a ceramic connector block 120 by which an electrical connection is established with the lamp assembly 115. Electrical cables 105 extend rearwardly from the connector block 120.
The assembly further comprises a cup shaped heat shield member 136. The heat shield member has a front rim portion 137 and a rear portion 138 defining an aperture through which the lamp and mounting member assembly extends. The rear portion 138 includes two opposed part-cylindrical formations which partly embrace the ceramic connector block 120 when the light fitting is assembled.
The heat shield member 136 has two oppositely disposed openings 139 through which the end parts of the arms 126, with the pivot formations 130 thereon, extend. The assembled condition of the light fitting, as shown in Figure 10 is reached by firstly fitting the mounting member and a lamp assembly to a heat shield member, and then fitting such sub-assembly rearwardly into the light fitting, resiliently deforming the arms 126 towards one another until their pivot formations 130 are able to.snap into engagement with the base 113 of the recess 112 of the light fitting. Normally one of the pivot formations 130 would be thus engaged, followed by the other formation. The dimensions of the parts are such that when such assembly has been carried out, the rear surface of the heat shield member 136 has contact with the light fitting in a substantially uninterrupted line in the annular region between the parts 109, 108 of the light fitting. By virtue of this, there is no or virtually no clear passage between the front and rear of the light fitting. The light fitting thus achieves a high fire safety rating for use in suspended ceilings or the like.
The assembly of lamp and heat shield is able to tilt and rotate in the light fitting in the manner above described. Rotation through an angle of more than 180° may be prevented by providing pressed indentations 140 in the base 113 of the recess 112 in the light fitting, to be contacted by the formations 130 on arms 126. The front rim portion 137 of the heat shield member may be able to pass just beneath the edge of the flange 110 of the light fitting as shown in Figure 10, to provide a detent so that such a position of maximum tilting can be held in a vibration-resistant manner.
When the light fitting is to be installed in, for example, a suspended ceiling, an insulating washer as shown at 104 would be interposed between the flange 110 and a panel of such ceiling. The light fitting may be retained in such a panel by a retaining member 143 which as shown in Figure 11 may take the form of an elongate length of thick metal wire with a part-circular portion 144 which is able to be snap engaged, by resilient deformation, with the groove 107. The ends of the piece of wire may take the form of limbs long enough to extend to rest upon the panel supports of the suspended ceiling, so that the weight of the light fitting is borne by the supports rather than the panel. A transformer or other low voltage electrical power supply for the halogen lamp assembly or an electrical connector block, may be carried by an end of the retaining member 143.
Alternatively a spring clip or clips as the clips 42 may be used to retain the light fitting in a ceiling panel. One such clip may be used in conjunction with a retaining member having one limb only extending from a part-circular portion engaging groove 107. Even if not required for retaining the light fitting in a panel, e.g. if two spring clips as 42 are used, a retaining member engaging the groove 107 may be used to carry a transformer or a connector block.
The heat-insulating washer 104 could if desired be shaped to extend from the region of the flange 100 to overlie additionally the portions 111, 108 of the light fitting. If this is done, a further improvement in the fire safety rating of the light fitting is obtained, by preventing high temperatures being reached behind the fitting.
The invention thus provides a means of mounting a lamp assembly which is simple and economical in manufacture and convenient in use. The mounting member may, when suitable tooling has been established, be mass-produced at competitive cost. Removal and fitting of the lamp assembly, including the mounting means, from and to the light fitting can readily be effected. In the case where the light fitting is retained in a panel of a suspended ceiling by a retaining member 143 whose limbs rest on the panel supports of the ceiling it will be appreciated that not only is the weight of the light fitting borne by the supports rather than the panel but also the light fitting will, in the event of fire, help support such panel in the region thereof above the flange of the light fitting.
The features disclosed in the foregoing description, or the accompanying drawing, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.