NZ504922A - Light fitting with reflector on one side and perforated heat shield on other side - Google Patents

Abstract

The light fitting has reflector 2 on one side of lamp receiving fixture 18 and perforated heat shield 17 located on the opposite side of fixture 18. Shield 18 is angled relative to the fixture. Typically the heat shield may be inverted V-shaped or single ridge and double-hipped shaped.

Description

PNTEqL^TUAL pR°pERTVr i office OF N.z.

I " 1 OCT 2001 | I RECEIVED I PATENTS FORM NO. 5 Fee No. 4: $250.00 Our ref: 25530/5 HB PATENTS ACT 1953 COMPLETE SPECIFICATION SHIELDING DEVICE I Paul Andrew Cronk, an Australian Citizen of Unit 1, 65 Evans Street, Harbord, New South Wales, 2096, Australia hereby declare the invention, for which I/We pray that a patent may be granted to me/us, and the method by which it is to be performed to be particularly descnbed m and by the following statement: 1 To be followed by Page 1A James & Wells Ref 293 IP 1 SHIELDING DEVICE Background of the Invention This invention relates to improvements in devices for reflecting light emitted by artificial sources.

Description of the Prior Art Modern industrial requirements for artificial lighting are extensive, varied, and constantly expanding.

Many types of reflector devices associated with artificial illumination of industrial spaces are currently known, but these generally require that a fixed shape and/or a fixed lamp mounting position within that shape be precisely specified to create optimal light distribution for a particular purpose. For example, a 'chinaman hat' reflector might 15 commonly be used m a situation where a wide, uniform spread of light is required. In this case, the spreading of light is largely dependent on the fixed internal angle of the cone shaped 'chinaman hat' reflector. The uniformity of light emitted is therefore largely dependent on the non-adjustable lamp positioning within that reflector. These known devices have the disadvantage that their rigid, non-adjustable, designs limit their efficient 20 use to a relatively small range of applications.

The Applicant's related New Zealand Patent No. 285,349 (and foreign equivalents) relates to a novel reflector having adjustable curvature, which overcomes such disadvantages of the prior art.

Horizontally mounted lamps coupled with appropriate reflectors, such as defined in the aforementioned patent, are popular and fulfil industrial requirements m most cases, however, their efficiency is limited. The closer these fittings can be placed to the 'target area' the better the overall efficiency and the greater the intensity. However, there comes 30 a point where the intensity and heat of the light beam directly below the lamp (focal hot spot) limits closer placement. In these conditions, addition of a 'heat shield' (as outlined intellectual property office of n.z. 0 3 DEC 2001 received 293 IP 2 below) can help redistribute excess light and heat from the 'hot spot' to other areas below the reflector, thereby dramatically increasing uniformity, functionality and efficiency m these extreme applications. This heat shield is supenor to the prior art because it relies only on direct reflection toward a target area below the lighting fixture. It does not reflect 5 substantial quantities of radiation back towards the lamp and reflector for (inefficient) re-reflection. Hence, the function of the heat shield is totally separable from that of the reflector it is coupled with, not limiting it to use in conjunction with any specific reflector design.

Summary of the Invention The present invention seeks to provide an adjustable reflecting device which substantially overcomes or at least ameliorates the disadvantages of the prior art.

According to a first aspect of the present invention there is disclosed a light fitting 15 comprising a lamp receiving fixture having first and second opposite sides, and a reflector means, the reflector means being mounted to said first side of the lamp receiving fixture to produce a beam of light from said light fitting when said lamp receiving fixture contains an illuminated lamp, wherein said light fitting also includes a heat shield located on said second side of said lamp receiving fixture and m said beam of light, said heat 20 shield having at least one surface facing said lamp receiving fixture and angled thereto to reflect light from said lamp, and also having a plurality of apertures therein through which some of the light emitted by said lamp can pass.

According to a second aspect of the present invention there is disclosed a method 25 of shielding a beam generated from a light fitting comprising a lamp receiving fixture having first and second opposite sides and a reflector means, the reflector means being mounted to said first side of the lamp receiving fixture to produce said beam from said light fitting when said lamp receiving fixture contains an illuminated lamp, said method comprising the step of:-30 locating a heat shield to said second side of said lamp receiving fixture and m said beam of light, said heat shield having at least one surface facing said lamp receiving fixture and intellectual p*0"epjy office of ' 0 3 DEC m\ RECEIVL 293 IP 3 angled thereto to reflect light from said lamp, and also having a plurality of apertures therein through which some of the light emitted by said lamp can pass.

Brief Description of the Drawings 5 The present invention will become more fully understood from the following description of a preferred but non-limiting embodiment thereof, described in connection with the accompanying drawings, wherein.

FIG. 1 shows a preferred embodiment of the shielding device m accordance with the present invention; FIG. 2 shows an alternatively preferred embodiment of the shielding device of the invention; FIG. 3 shows an exploded view of one example of an adjustable reflector device used in conjunction with the shielding device of the present invention; FIG. 4 shows a disassembled view of the reflector components of FIG. 3, 15 depicting the protruding skirts, present on sheet members; FIG. 5 shows an assembled view of the reflector components of FIG. 3 prior to flexing, depicting the alignment of the sheet members; FIG. 6 illustrates the incident and reflected electromagnetic radiation when a double-parabolic reflector is used without a shielding device; and, FIG. 7 illustrates a similar depiction to that of FIG. 6, but when a shielding device, in accordance with the present invention is used Detailed Description of the Preferred EmbodimentsCs) Throughout the drawings, like numerals will be utilised to represent similar 25 features, except where expressly otherwise indicated.

Also, throughout the specification, the term "a double parabolic" is utilised to describe the shape of a reflector device when it is m its flexed position, and retained against the bias of its normal resilience, as for example, as shown in FIG. 3 of the 30 drawings. In considenng this definition, it should be appreciated that any size, shape or intellectual p^o^rty OFFICF nr 0 3 DEC 2001 received 293 IP 4 width of double parabolic or similar shape should be considered to fall withm the scope of this definition.

The present invention provides a shielding device, which is substantially V-5 shaped and perforated, and which is used m association with a reflector device. A preferred arrangement of a reflector device which may be used, is an adjustable light reflector device having a resilient reflective sheet, flexed to form a double parabolic shape, which is held m place against its resiliency by adjustable retainers located at each end of the sheet and an independently adjustable lamp mount which attaches to the sheet 10 when it is in the retained position.

Referring to FIG 1, there is shown a shielding device 17, which is generally V-shaped, which may be attached to a lamp fitting or lamp socket by means of an attachment means 28. The attachment means 28 is shown embodied as a cylindrical 15 sleeve, which may be secured by a grub screw 19 to the lamp fitting or lamp socket. An arm 29 connects the attachment means 28 to the shielding device 18. The shielding device 17 is provided with perforations 30, which will allow the transmission of some radiant emissions therethrough, whilst other radiant emissions will be reflected by the surface of the shielding device, as will be further detailed hereinafter. The sizing, 20 spacing, patterning, etc., of the perforations will control the amount of radiation required according to the application, the type of reflector used, etc.

Referring to FIG. 2, there is shown an alternative, but also preferred, embodiment of the invention. In the embodiment of FIG. 2, the reflector may also be descnbed as V-25 shaped, but its ends are also pitched, somewhat resembling a single gable double hipped 'house-roof shape. The shielding device 17 of FIG. 2 will disperse light and heat m four directions from the 'hot spot'. That is, the radiation will be reflected left, nght, forward and behind the emission source. The embodiment of FIG. 2 also shows an alternative embodiment of an attachment means 28, in this case, the attachment means 28 includes a 30 bolt-on-bracket arrangement. intellectual property office of n.z. 0 3 DEC 2001 RECEIVED 293 IP Referring to FIG. 3 it can be seen that a preferred embodiment of adjustable reflector device used m conjunction with the shielding device of this invention includes a two piece resilient sheet formed by two sheet members 1 and 2, having a protruding skirt parallel with the longer edge thereof. The sheet members 1, 2 are each substantially 5 rectangularly shaped, detachably joined about a spine portion 3 and then flexed back against their normal resilience to produce a double parabolic shape, as shown. Thus one edge and associated skirt of one sheet member fits neatly inside the corresponding skirt and edge of the other. The sheets 1, 2 are then fixed together and flexed back to achieve a curved shape, such as a double-parabolic shape. The sheet may be made of any suitable 10 material such as colour bonded metal, metal, fibreglass, or plastic. The pair of sheet members 1, 2 can be integrally manufactured in a one piece construction - as opposed to being separately formed. The sheets 1, 2 are adjustably secured by a pair of chain 4 and hook 5 retainers (only one retainer being shown because of the orientation of FIG. 3). The retaining means can be a chain, wire or like means, optionally adjustable in length. 15 A pair of threaded bolts 6 and 7 pass down through holes 8 and 9 m the top of the assembled reflector and are secured by nuts 10 and 11.

A lamp mount 12 attaches to bolts 6 and 7 through holes 13 and 14 and is adjustably secured by attaching nuts 15 and 16. The lamp mount comprises a sliding 20 plate that adjusts along a pair of threaded bolts which pass through holes in the sheet.

Nuts are used to secure bolts to the sheet and to provide a means of adjustment for the sliding plate. The lummaire mount may be designed m any fashion, adjustable or non-adjustable, so long as it does not substantially inhibit flexibility of the sheet members when attached thereto.

The V-shaped perforated heat shield 17 slides onto the lamp fitting 18 and is secured to the underside thereof by a grub screw 19. The heat shield is preferably provided about at least part of the element or filament portion of the lighting means, and is attached via a slender arm, to a piece of cylindrical tube which slides onto the lamp fitting and is secured with a grub screw. The heat shield may be perforated with any number of holes of any size or shape so long as it is substantially w attanVi intellectual property office of n.z. 0 3 DEC 2001 received 293 IP 6 to the lamp fitting by any method capable of securing the shield parallel to the under side of the lamp. Folds at 20 and 21 produce rigidity and strength m the flexed and retained sheet members. The resilient reflective sheet may comprise one or any number of sheet members and any necessary reinforcing members fashioned so as to approximate the 5 predefined shape and conditions required for formation of a flexible double parabolic shape as herein defined Referring to FIG. 4 it can be seen that sheet members 1 and 2 which form the reflector, each have two folds 20, 22 and 21, 23 which create associated skirts 24, 25 and 10 26,27.

Referring to FIG 5 it can be seen how sheet members 1 and 2 are joined at an angle. Skirts 27 and 25 are attached to the bodies of sheet members 1 and 2 to create a reinforced joint about the newly created spine 3.

By appropriate adjustment of the reflective device described above, many and varied desirable conditions of artificial illumination may be achieved. Hence the need to employ more than one reflective device to efficiently service a range of discrete tasks may be reduced or abolished.

It will be realised that the reflector device according to this invention is not restricted to the specific shape and construction of the resilient sheet shown in the example, but may use a sheet fashioned from one, two, or more pieces of suitable material of any suitable shape or size so long as the essential feature of being flexed back 25 against a spine or axial crease to create an adjustable double parabolic shape or other similar shape is achieved.

Referring to FIG. 6, a double-parabolic shaped reflector device is shown in cross-section, to illustrate the incident and reflected radiation associated with such a reflector 30 from a light source positioned thereunder. Incident light I is shown being transmitted from the light source. Some of this incident light travels towards the reflector and is INTELLECTUAL PROPERTY OFFICE OF N.Z. 0 3 DEC 2001 received reflected as reflected light R, according to the general principle that the Angle of Reflection equals the Angle of Incidence The double parabolic shaped reflector shown in FIG. 6 is a special shape so far as reflection is concerned, m that it does not reflect any heat or light back towards the light source or bulb, or create any 'left to right' or 'right to 5 left' cross reflection, which is very inefficient.

FIG. 7 illustrates a diagram similar to that of FIG. 6, but in which a shielding device 17 in accordance with the present invention is used. In the illustrated arrangement, incident light passing through the shielding device 17 is represented as Ih, 10 whilst light reflected by the shielding device is represented as Rh. Using the double parabolic shaped reflector, as shown m FIG. 7 in conjunction with the heat shield 18, cannot produce any re-reflection of any substantial quantity. It is considered that re-reflection would still be minimal m the event that a non-parabolic reflector is used.

It will be appreciated by persons skilled in the art that variations and modifications may be made to the shielding device of the present invention, whilst still achieving the functional advantages of the descnbed embodiments. As such, variations to the shape, the nature and extent of the perforations, the means of attachment, etc., should all be considered to fall withm the scope of the invention as hereinbefore 20 descnbed and as hereafter claimed. intellectual property office of n.z. 0 3 DEC 2001 RECEIVED

Claims (1)

1. 293 IP 8 5 10 2. 15 3. 20 4. 5. 25 6. 30 7. A light fitting comprising a lamp receiving fixture having first and second opposite sides, and a reflector means, the reflector means being mounted to said first side of the lamp receiving fixture to produce a beam of light from said hght fitting when said lamp receiving fixture contains an illuminated lamp, wherein said hght fitting also includes a heat shield located on said second side of said lamp receiving fixture and in said beam of light, said heat shield having at least one surface facing said lamp receiving fixture and angled thereto to reflect hght from said lamp, and also having a plurality of apertures therein through which some of the hght emitted by said lamp can pass. The light fitting as claimed m claim 1 wherein said heat shield has a pair of said angled surfaces facing said lamp receiving fixture, said pair of surfaces having a generally V-shaped configuration. The hght fitting as claimed in claim 2 wherein said pair of surfaces intersect to form a ridge line, said reflector means is elongate having a longitudinal axis, and said heat shield is mounted with said ridge line substantially parallel to said longitudinal axis. The light fitting as claimed in claim 3 and having a further pair of said angled surfaces facing said lamp receiving fixture. The hght fitting as claimed m claim 4 wherein the four surfaces of said heat shield have the configuration of a single ridged double hipped roof. The hght fitting as claimed m any one of claims 1-5 wherein said plurality of apertures are arranged m a regular grid pattern. The light fitting as claimed in any one of claims 1-6 wherein said reflector means is adjustable to alter the shape of said beam. —""" - ,Y i 1NTEUEC - , off o 3 DEL tUOl RECEiv 5 9. 10. 10 15 11. 20 25 12. The light fitting as claimed in claim 7 wherein said reflector means has a double parabolic shape. The hght fitting as claimed in claim 7 wherein said reflector means is as claimed in any one of the claims of NZ Patent No. 285,349. A method of shielding a beam generated from a light fitting comprising a lamp receiving fixture having first and second opposite sides and a reflector means, the reflector means being mounted to said first side of the lamp receiving fixture to produce said beam from said light fitting when said lamp receiving fixture contains an illuminated lamp, said method comprising the step of.-locatmg a heat shield to said second side of said lamp receiving fixture and in said beam of light, said heat shield having at least one surface facing said lamp receiving fixture and angled thereto to reflect light from said lamp, and also having a plurality of apertures therein through which some of the hght emitted by said lamp can pass The method as claimed in claim 10 wherein said reflector means is elongate and has a longitudinal axis, said heat shield comprises a pair of said angled surfaces facing said lamp receiving fixture and which intersect to form a ridge line, said method comprising the further step of mounting said heat shield with said ridge line substantially parallel to said axis. The method as claimed in claim 10 or 11 wherein said reflector means is adjustable to alter the shape of said beam, said method comprising the step of adjusting the shape of said reflector so that light from said beam reflected from said heat shield is not reflected from said reflector means. intellectual property office of n.z. 0 3 DEC 2001 RECEIVED