AU2012100360B4 - Lighting reflector - Google Patents

Abstract

A lighting reflector is described. The lighting reflector comprises a reflector frame (10) having a forward end and an opposite rear end, and opposed side walls 5 (12, 14) defining an interior space of the frame therebetween. The frame is configured for reception of an electric lamp (22) within the interior space, and a reflector (18) having a reflective surface (20) for reflecting light emitted by the lamp forwardly from the frame and being disposed between the side walls to form a back wall of the frame. The reflective surface of the reflector has a plurality of reflective facets (26 i-v) 10 transversly to the side walls and which are arranged side by side at an angle with respect to one another whereby the reflective surface has a general concave curvature extending in a rearward to forward direction of the frame. A light fitting comprising the lighting reflector and a method for providing the light reflector is also provided.

Description

1. AUSTRALIA Patents Act 1990 (Cth) COMPLETE SPECIFICATION APPLICANT BRYAN JULIAN LIEBOWITZ TITLE LIGHTING REFLECTOR The invention is described in the following statement including the best method known to me/us: -2 LIGHTING REFLECTOR FIELD OF THE INVENTION 5 The present invention relates to a lighting reflector suitable for use in, but not limited to, outdoor lighting fixtures. The invention also relates to a method for fabricating the lighting reflector. BACKGROUND OF THE INVENTION 10 Train carriages are commonly parked in stabling yards where they are inspected for damage and undergo cleaning and minor maintenance when not in duty. The stabling yards generally comprise a number of railway track sections arranged alongside one another with respective pathways provided between them to allow 15 workmen and cleaners access to the carriages. The pathways, therefore, must be well lit during night hours for safety reasons. This is generally achieved by light poles providing raised lighting along the pathways. One factor that impacts on the cost of erecting such lighting installations is pole spacing and thereby, the number of poles required to provide the requisite level of lighting along the pathway(s). Pole lighting 20 installations are also commonly employed to light pathways in public parks and elsewhere. Alternative lighting systems which may reduce costs associated with such lighting installations whilst at the same time are attractive and provide for the required level of lighting are therefore desirable. 25 SUMMARY OF THE INVENTION In an aspect of the invention there is provided a lighting reflector, comprising: a reflector frame having a forward end and an opposite rear end, and opposed side walls defining an interior space of the frame therebetween, the frame being 30 configured for reception of an electric lamp within the interior space; and a relector having a reflective surface and being disposed between the side walls to form a back wall of the frame, the reflective surface having a plurality of reflective -3 facets lying transversly to the side walls and being arranged side by side at an angle with respect to one another whereby the reflective surface has a general concave curvature extending in a rearward to forward direction of the frame for reflecting light emitted by the lamp forwardly from the frame. 5 In a related embodiment there is provided a method for fabricating a light reflector, comprising: providing a reflector with a reflective surface; and connecting the reflector to opposite side walls to form a frame, the reflector being disposed between the side walls to form a back wall of the frame for reflecting 10 light emitted by an electric lamp forwardly from the frame by the reflective surface when the lamp is received in an interior space of the frame defined between the side walls, the reflective surface having a plurality of reflective facets lying transversly to the side walls and being arranged side by side at an angle with respect to one another whereby the reflective surface has a generally concave curvature extending in a 15 rearward to forward direction of the frame. Typically, the frame is configured for reception of the lamp in the interior space of the frame so as to be orientated across the interior space in a direction from one of the side walls to the other side wall, and wherein the reflective surface of the reflector is disposed forwardly with respect to the lamp when the lamp is received in position 20 within the interior space. Typically, respective of the reflective facets of the reflective surface of the reflector are essentially planar. Typically, the angle at which at least some of the reflective facets are arranged increases from one facet to the next relative to horizontal in the forward direction of the 25 frame. Typically, the width of respective of the reflective facets also increases from one to the next in the forward direction of the frame. Typically, the frame further comprises a rear wall connecting the side walls of the frame together, wherein the rear wall has a reflective surface with a plurality of 30 reflective facets lying transversly to the side walls and which are arranged side by side at an angle with respect to one another whereby the reflective surface of the rear wall has a generally concave curvature extending in the forward direction of the frame.

-4 Typically, the frame also incorporates a baffle extending across the interior space of the reflector frame and disposed in front of the curvature of the rear wall for reception of the lamp between the rear wall and the baffle. Typically, the reflector and the side walls of the reflector frame are connected 5 together by tab in slot connections. Most typically, the reflector has a plurality of peripheral tabs and the side walls of the frame are provided with correspondingly positioned slots, and the reflector and the side walls of the frame are connected together by inserting the tabs of the reflector into the slots of the side walls and bending the tabs to form the tab in slot connections. 10 In yet another aspect of the invention there is provided a light fitting, comprising: a frame having a forward end and an opposite rear end, and opposed side walls defining an interior space of the frame therebetween; a lamp holder for receiving an electric lamp whereby the lamp is orientated 15 across the interior space in a direction from one of the side walls to the other side wall; and a reflector having a reflective surface and being disposed between the side walls to form a back wall of the frame, the reflective surface having a plurality of reflective facets lying transversly to the side walls and being arranged side by side at an angle 20 with respect to one another whereby the reflective surface has a general concave curvature extending in a rearward to forward direction of the frame for reflecting light emitted by the lamp forwardly from the frame. In use, the reflector of the reflector frame is generally arranged substantially horizontally so as to face downwardly, the arrangement and configuration of the 25 reflector in at least some embodiments of the invention being such that light from the lamp is reflected forwardly of the light fitting. However, the reflector also reflects light downwardly such that excellent light intensity can be obtained over the area to be lit for a given lamp. The area lit by the reflected light is generally elongate in dimension and as such, at least some embodiments of the invention find particular application for 30 lighting pathways and can be located atop a light pole so as to be orientated along the pathway for this purpose. As enhanced downwardly directed lighting may be obtained, the spacing between light poles may be increased whilst retaining a requisite level of -5 lighting along the pathway. Accordingly, lighting reflectors and light fittings described herein in accordance with one or more embodiments of the invention offer the potential to decrease the number of light poles in a given lighting installation with a consequential reduction in costs associated with erection of the lighting installation. In 5 particular, embodiments of the invention have particular application for lighting train carriage stabling yards and similar situations where a high level of lighting is needed and which conventionally have required relatively closely spaced light poles to obtain the requisite lighting level. However, it will be understood that embodiments of the invention are not limited to use in stabling yards, and can be employed for instance ito 10 the lighting other areas such as driveways, fenced yards, loading docks, and entrances to commercial or private buildings or dwellings, as well as for lighting public pathways and walkways in parks, reserves and elsewhere. Moreover, lighting reflectors embodied by the invention in one or more forms also provide for ease of fabrication from commercially available low cost sheet metal 15 sheeting with highly specular reflective surface(s). As such, embodiments of the invention may be fabricated rapidly and at relatively low cost. Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of 20 any other element, integer or step, or group of elements, integers, integers or steps. Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the 25 invention as it existed in Australia or elsewhere before the priority date of this application. The features and advantages of the present invention will become further apparent from the following description of embodiments thereof with reference to the accompanying drawings. 30 -6 BRIEF DESCRIPTION OF THE ACCOMPANY DRAWINGS Figure 1 is a perspective view of a lighting reflector embodied by the invention; Figure 2 is a plan view of the front of the lighting reflector of Fig. 1; 5 Figure 3 is an exploded view of the lighting reflector of Fig. 1; Figure 4 is a side view of a side wall of the lighting reflector of Fig. 3; Figure 5 is a side view of the opposite side wall of the lighting reflector of Fig. 1; and Figure 6 is a front view of the lighting reflector of Fig. 1. 10 DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION A lighting reflector embodied by the invention is shown in Fig. 1, and comprises 15 an open reflector frame 10 formed from opposite side wall panels 12 and 14, a rear wall panel 16 and a reflector panel 18 forming a back wall of the frame, wherein the panels are all fabricated from lightweight sheet metal. The reflector 18 has a highly specular reflective surface 20 for reflecting light emitted from the electric lamp 22 through the open front face 24 of the frame in use. The reflective surface 20 of the reflector 18 20 comprises a plurality of side by side elongate reflective facets 26 (i-v) (best shown in Fig. 2) that extend transversely across the interior space 28 of the frame defined between the opposite side walls 12 and 14. The facets are essentially planar and are arranged at an angle with respect to one another, the angle increasing from one facet to the next relative to horizontal providing the reflective surface 20 with a generally 25 concave curvature extending in a direction from the rear end 30 to the opposite forward end 32 of the frame. In the embodiment shown, the reflector has five reflective facets 26, although other embodiments of the invention may have a different number. Generally, however, the reflector 18 will have at least three consecutive facets 26 (e.g., facets 26 (ii-v) 30 arranged at an angle which increases from one facet to the next relative to horizontal in the forward direction of the frame. Typically, the angle at which these facets are orientated will increase in a range of about 100 to approximately 150 from one to the -7 next. By way of example, the angle at which facets 26 (i-v) are arranged relative to horizontal in the embodiment shown in Fig. 1 are respectively, about +20.7, 0', -12.8', -25.2' and -36.10. As indicated above and as shown in Fig. 2, initial reflective facet 26 (i) has an 5 opposite slope compared to the other facets 26 (ii-v) of the reflector. Due to the curvature of the reflector 18, the depth of the interior space 28 of the reflector frame 10 generally decreases from the rear region of the reflector 18 along the frame in the forward direction. As can also be seen, the width of respective of the facets 26 increases from one to the next in the forward direction of the frame 10. 10 The lamp 22 is elongate and is received in the interior space 28 of the frame through an opening 34 provided in left side wall 12 so as to be orientated across the interior space in a direction from side wall 12 to side wall 14 and lie substantially parallel to respective of the reflective facets 26 of the reflector. A baffle in the form of an elongate metal strip element 36 with a reflective surface is spaced from the rear wall 15 for reception of the lamp between the rear wall and the baffle. The baffle strip element is connected at respective ends to the opposite side walls 12 and 14 whereby the reflective surface 37 of the baffle is inclined at an angle to reflect light from the lamp generally forwardly toward the reflector. An exploded view of the reflector frame 10 is shown in Fig. 3. As can also be 20 seen, the reflector panel 18 is provided with tabs 38 spaced apart from one another along each side 40 and 42 of the reflector. Further spaced apart tabs 38 are likewise provided along respective sides 46 and 48 of the rear wall 16, and at each end of the baffle strip element 36. Similarly to the reflector 18, the rear wall 16 has a reflective surface 50 comprising a plurality of elongate reflective facets 52 lying transversely to 25 the side walls and which are arranged side by side at an angle with respect to one another whereby the reflective surface 50 has generally concave curvature extending in the rearward to forward direction of the frame 10. The forward end of the rear wall abuts the rear end of the reflector panel 18 defined by reflective facet 26(i). Further, the baffle strip element 36 is disposed directly in front of the apex of the curvature of the 30 rear wall and is slightly offset rearwardly with respect to the centre of the opening 34 in the left side wall 12 for reception of the lamp.

-8 To connect the reflector 18 to the side walls 12 and 14, the tabs 38 of the reflector are inserted into respective corresponding slots 54 provided in the side walls and are then bent over by hand to lie flat against the relevant wall 12 or 14 to form tab in slot connections holding the reflector and side walls together. Likewise, the tabs 38 5 of the rear wall 16 and baffle strip element 36 are inserted into the corresponding slots 54 of the side walls and bent over to form tab in slot connections securing the rear wall and opposite side walls together and the baffle element in position within the interior space 28 of the frame 10. The lighting reflector also comprises a metal front panel element 44 to which 10 the outwardly directed flanges 56 of the rear wall 16 and side walls are mounted and fixed via mechanical fasteners such that the front element forms a border around the open front side of the frame 10. Whilst in the embodiment shown the frame 10 is fixed to the front panel element 44 via rivets (e.g., pop rivets) inserted through aligned holes 58 and 60 of the panel element 44 and the flanges 56 of the rear and side walls of the 15 frame 10, other suitable fastening systems may also be used (e.g., other mechanical fasteners, spot welds etc.). The front panel element 44 projects laterally from the frame 10 providing side flanges 62 for mounting of the frame to a waterproof housing of a light fitting/fixture (not shown). The housing generally comprises a casing into which the reflector frame 20 is fitted, and a front transparent or translucent cover that is fitted over the front face of the frame 10 and secured to the casing. The cover can be secured to the casing by any suitable conventional means such as mechanical fasteners (e.g., screws) or clips. Alternatively, for example, the cover can be hinging to the casing on one side and be releasably clipped or otherwise fastened to the casing on the other side to facilitate 25 maintenance to the light fitting without the need to fully remove the cover from the casing. A side view of the left side wall 12 illustrating the position and orientation of respective of the slots 54 for reception of the tabs 38 of the reflector 18 and rear wall 16 is shown in Fig. 4. The right side wall 14 is essentially a mirror image except that it is 30 not provided with the opening 34 for insertion of the lamp. A side view of the left side wall of the frame in which the lamp is inserted into the frame 10 is shown in Fig. 5, and a front end view is shown in Fig. 6. As can be seen in Fig. 6, the side walls 12 and 14 -9 of the frame are substantially planar and are arranged so as to be sloped relative to one another providing the frame 10 with a tapered profile whereby the side walls fan outwardly from the reflector 18 in opposite directions. An appropriate lamp holder (e.g., a bayonet cap holder) for the lamp 22 can be 5 provided either in the light fitting in which the reflector frame 10 is disposed in use. Alternatively, the lamp holder can be fitted in the opening 34 to be retained in position in the left side wall 12. The lamp is normally a high-intensity discharge (HID) lamp such as a metal halide lamp, ceramic metal halide lamp, sodium vapour lamp or xenon short-arc lamp, and is arranged such that the electric arc of the lamp is situated 10 substantially midway between the side walls 12 and 14 of the reflector frame. Generally, the lamp 22 has a rating of from about 70 watts to about 1000 watts although in some embodiments of the invention, higher or lower wattage lamps may be employed. Typically, the lamp 22 is a short form metal halide lamp or other short form HID lamp, examples of which include HID lamps commercially available under the 15 CosmoPolisTM brand (Philips). However, it will be understood any suitable type of lamp for the intended purpose of the light reflector or light fitting can be employed. In use, a light fitting embodied by the invention is mounted on the top of a light pole or in an otherwise elevated position such that the reflector frame 10 is disposed substantially horizontally with the front of the reflector frame oriented face down. To 20 optimise the efficiency of the reflector frame, the side walls 12 and 14 each have a respective reflective surface facing the interior space of the frame. These surfaces as well as the reflective surface 50 of the rear wall 16 of the frame 10 can be dimpled (e.g., regular or irregular dimpling patterns) or otherwise be provided with surface indentations for enhancing reflection of light frontwardly from the lamp. The reflective 25 surface 20 of the reflector 18 will generally have a reflective efficiency of at least about 95% and most usually, a reflective efficiency in the order of about 98%. Suitable metal sheeting having a highly specular reflective face from which the reflector 18 can be fabricated include commercially available Miro4TM specular aluminium sheeting. A light fitting embodied by the invention finds particular application for lighting 30 pathways in train carriage stabling yards and generally, will be fitted on the top of light poles for this purpose so as to be orientated in a direction along the ground surface/pathway to be lit. In some embodiments of the invention, the single reflector -10 frame 10 as described herein can be provided atop a light pole. However, embodiments in which a number of light fittings are situated atop the one light pole are also provided. For instance, one light fitting embodied by the invention can be provided on the pole so as to be orientated along a pathway in one direction and an adjacent light fitting of the 5 invention can be orientated in the opposite direction along the pathway. In particular, whilst embodiments described herein project light generally downwardly and forwardly of the light fitting, they also exhibit excellent vertical illumination by virtue of the orientation and curved profile of the reflector 18, and the position of the lamp with respect to the reflector 18. Vertical illumination is 10 particularly important for areas that are under CCTV surveillance. Moreover, as intensity of the light over the lit area may be enhanced for the given lamp 22 employed, the invention in one or more forms may allow the spacing between light poles along the ground surface/pathway(s) to be increased thereby decreasing overall costs for a given lighting installation. 15 Accordingly, a light fitting embodied by the invention may provide one or more of the following advantages: * An alternative to existing light fittings conventionally used in train carriage stabling yards or in other lighting situations ; * The emission of light generally forwardly of the light fitting with 20 excellent vertical illumination; * Highly efficient lighting of a given area or pathway; * The enhancement of light intensity along a given area or pathway for a given lamp providing the potential to increase spacing between light poles or lighting positions; and 25 e Rapid and easy assembly of the lighting reflector providing for relatively low fabrication costs. It will be understood that whilst the embodiments of the lighting reflector described above have been fabricated by tab in slot connections fixing the reflector panel 18 to the side walls 12 and 14 as well as rear wall 16 of the reflector frame 10, the 30 fabrication of the frame can be achieved by any other suitable methods, such as by spot welding, the use of mechanical fasteners (e.g., self tapping screw, pop-rivets etc.) or a combination of those methods. Moreover, whilst in the embodiment(s) shown in the -11 accompanying drawings the lamp 22 is inserted through a single opening 34 in the left side wall of the frame 10, the lamp used can be mounted in a lighting frame embodied by the invention in any other suitable manner. Accordingly, it will be appreciated by persons skilled in the art that numerous 5 variations and/or modifications may be made to the above embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. 10

Claims (5)

1. A lighting reflector, comprising: a reflector frame having a forward end and an opposite rear end, and opposed 5 side walls defining an interior space of the frame therebetween, the frame being configured for reception of an electric lamp within the interior space; and a reflector having a reflective surface and being disposed between the side walls to form a back wall of the frame, the reflective surface having a plurality of reflective facets lying transversly to the side walls and being arranged side by side at an angle 10 with respect to one another whereby the reflective surface has a general concave curvature extending in a rearward to forward direction of the frame for reflecting light emitted by the lamp forwardly from the frame.

2. A lighting reflector according to claim 1 configured for reception of the lamp in the interior space of the frame so as to be orientated across the interior space in a 15 direction from one of the side walls to the other side wall, and wherein the reflective surface is disposed forwardly with respect to the lamp when the lamp is received in position within the interior space.

3. A lighting reflector according to claim 1 or 2 wherein respective of the reflective facets of the reflector border each adjacent said facet and are essentially 20 planar, the angle at which at least some of the reflective facets are arranged increases from one facet to the next relative to horizontal in the forward direction of the frame, and the width of respective of the reflective facets increases from one to the next in the forward direction of the frame.

4. A lighting reflector according to any one of claims 1 to 3 wherein the frame 25 further comprises a rear wall connecting the side walls of the frame together, the rear wall having a reflective surface formed by a plurality of reflective facets lying transversly to the side walls and which are arranged side by side at an angle with respect to one another whereby the reflective surface of the rear wall has a general concave curvature extending in the rearward to forward direction of the frame. 30

5. A light fitting, comprising: a frame having a forward end and an opposite rear end, and opposed side walls defining an interior space of the frame therebetween; -13 a lamp holder for receiving an electric lamp whereby the lamp is orientated across the interior space in a direction from one of the side walls to the other side wall; and a reflector having a reflective surface and being disposed between the side walls 5 to form a back wall of the frame, the reflective surface having a plurality of reflective facets lying transversly to the side walls and being arranged side by side at an angle with respect to one another whereby the reflective surface has a general concave curvature extending in a rearward to forward direction of the frame for reflecting light emitted by the lamp forwardly from the frame. 10