AU2014201253B2

AU2014201253B2 - Light cover/diffuser for food cabinets

Info

Publication number: AU2014201253B2
Application number: AU2014201253A
Authority: AU
Inventors: John Maslen
Original assignee: Maslen Technology Australia Pty Ltd
Current assignee: Maslen Technology Australia Pty Ltd
Priority date: 2007-04-26
Filing date: 2014-03-06
Publication date: 2014-09-25
Anticipated expiration: 2028-04-28
Also published as: AU2014201253A1

Abstract

TITLE: LIGHT COVER/DIFFUSER FOR FOOD CABINETS A light cover/diffuser (10) for a mullion (CM, EM) of a refrigerator/freezer cabinet (C) has transparent inner and outer layer(s) or 5 shell(s) (20,30) to define an insulating air gap (40) and a space (50) to contain light source(s) (L). Insulating spacers (60) may be provided in the air space (40). -~ R

Description

P/00/011 Regulation 3.2 AUSTRALIA Patents Act 1990 ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Invention Title: "LIGHT COVER/DIFFUSER FOR FOOD CABINETS" The following statement is a full description of this invention, including the best method of performing it known to me/us: 1 TITLE: UGHT COVER/DIFFUSER FOR FOOD CABINETS BACKGROUND OF THE INVENTION I. Field of the Invention THIS INVENTION relates to a light cover/diffuser for food 5 cabinets. The invention is particularly suitable for, but not limited to, a light cover/diffuser for refrigerator cabinets, but may be used for other controlled or ambient environmental applications, including freezers for the storage of foods or other articles. 10 2. Prior Art In supermarkets and other food retail stores, food kept under controlled temperature conditions, eg at ambient temperature, refrigerated temperatures, or below freezing temperatures, are typically displayed in one or more cabinets where the air temperature is maintained within strictly 15 controlled limits. Typically, these cabinets can extend along the whole, or part of the aisles in the supermarkets or shops, and generally have glass-fronted doors, which allow the food articles within the cabinets to be easily and attractively viewed, while also allowing easy access to the goods, The 20 provision of the doors minimises the ingress of heat into the cabinets, thereby minimising the size and operational requirements for the refigerating/freezer units used to maintain the desired temperatures within the cabinets. It is essential that the articles, eg., food, within the cabinets can 25 be easily viewed by consumers, requiring the provision of lighting within the cabinets. However, the lighting, whether incandescent, fluorescent, or of other lighting types, creates heat energy which tends to raise the temperature within the cabinets and which nust be countered by the refrigerator/freezing units.

2 SUMMARY OF THE PRESENT INVENTION It is an object of the present invention to provide a light coven diffuser suitable for installation, e.g., on a mullion in a food cabinet or other displaylstorage unit, 5 It is a preferred object of the present invention to provide such a light cover/diffuser which minimises any transfer of heat energy from the light source(s) within the light cover/diffuser to the air temperature within the cabinet. Other preferred objects of the present invention will become 10 apparent from the following description. In a broad aspect, the present invention resides in a refrigerator or freezer cabinet, suitable for foodstuffs, having: at least one vertical mullion; a substantially U-shaped light coverldiffuser, having spaced 15 legs mounted on the mullion within the interior of the refrigerator or freezer cabinet; an elongate space defined by the mullion and the light cover/ diffuser; and at least one light source in the elongate; 20 the light cover /diffuser including a first layer or shell of clear or translucent material forming the elongate space with the mullion; a second layer or shell of clear or translucent material, connected to the first layer or shell, and spaced therefrom; and 25 an air gap defined between the first and second layers or shells on at least one side of the first layer or shell opposed to the elongate space; the light cover / diffuser being operable to minimise transferof heat energy from the light source to the interior of the refrigerator or freezer cabinet 30 3 Preferably, third or subsequent layers or sheHs of clear or translucent material may be connected to the preceding layers or shells to define respective air gaps therebetween in the direction away from the space. 5 The adjacent ends of the first, second and subsequent layers may be sealed, or open. The, or each, air gap may contain air and/or other gases, and may be at least partially evacuated. Preferably, one or more spacers may be formed as part of the 10 ;ayers or shells, or interposed between the layers or shells, to create/maintain the air gaps between the layers or shels Preferably, the layers or shells are formed of clear or translucent materials such as plastics or glass or other suitable transparent or light transmitting materials; and layers) of semi-transparent or opaque 15 materials may be applied to the layers or shells, e.g., as masks, to create colours/patterns' designs/trade marks/other aesthetic effects, or the like, BRIEF DESCRIPTION OF THE DRAWINGS To enable the invention to be fully understood, preferred 20 embodiments will now be described with reference to the accompanying drawings in which: FIG, I is a perspective front view of a first embodiment of the present invention, showing the light cover/diffuser for a centre mullion before assembly and a light cover/diffuser for an end mullion as assembled; 25 FIGS. 2A and B are respective views of the light cover/diffuser for a centre mullion before and after assembly; FIG 3 is a perspective view of a light cover/diffuser for an end mullion; FIG 4 is a schematic end view showing the steps for assembly 30 of the light cover/diffuser for a centre mullion; 4 FIG. 5 is a similar view of the assembled light cover/diffuser FIG. 6 is a similar view for a light cover/diffuser for an end mullion; FIG is a schematic end view of a second embodiment of the 5 present invention; FG 8 is a schematic isometric view of the second embodiment FIG. 9 is an "exploded" isometric view of the two layers (or shells) of the second embodiment; 10 FIG. 10 is a schematic isometric view of a third embodiment; FIG 11 is a schematic end elevational view of a fourth embodiment; and FIG, 12 is a schematic end elevational view of a fifth embodiment. 15 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a typical refrigeration (or freezer) cabinet C for foodstuffs has a frame F with top and bottom rails TR, BR interconnected by centre- or end mullions CM, EM. The metal-framed glass doors (not 20 shown) are typically hinged on the end mullions EM and have latches releasably engaging strikers on the centre mullions CM, The light covers/difusers 10, 0A, respectively fitted to the centre- and end mullions CM EM are designed to direct at least part of the light from the light sources enclosed thereir into the interior of the cabinet C 25 to lluminate the foodstuffs stored therein. FIGS. 2A and 28 schematically illustrate the light cover/diffuser 10, centre mullion CM, and plastic cover strips CS, before and after assembly, respectively. FIG. 3 schematically illustrates the method of mounting the light 30 coverdiffuser 10, alternative constructions of which wil be hereinafter 5 described, to the centre mullion CM; which FIG, 5 schematically illustrates the final assembly. The light cover/diffuser 10 is formed from inner and outer shells, 20, 30 of transparent polycarbonate material, to form a substantially 5 U-shaped cover, with an internal air gap 40 and an elongate space 50 in which the light source(s) are fitted. (The light source(s) have suitable electrical fittings (not shown) mounted on the central web W of the centre mullion CM). The respective "legs of the light cover/diffuser 10 are engaged with the web W of the centre mullion CM and are secured thereto by the 10 substantially L-shaped cover strips CS and fasteners F. The cover strips CS conceal the mounting of the light cover/diffuser 10 to the centre mullion CM. A spacer 60, may be provided in the light cover/diffuser 10. If opaque, it will cause the light from the light source(s) to be directed inwardly 15 to, or outwardly from, the cabinet C, The light cover/diffuser 1 GA, for the end mullion EM, illustrated in FIG. 6, is also of U-shape, but narrower, and the insulating foam 60A causes all the light to be directed into the cabinet C. The light coverdiffuser 10A has an inner shell 20A, outer shell 20 30A air gap 40A and eloigate space 30A, as hereinbefore described. Referring to FIGS. 7 to 9, the light cover/diffuser 110 of a second embodiment is designed to be fitted to a refrigerated food cabinet (not shown), but may also be fitted to other cabinets storing food or other articles at, eg., ambient temperature or at reduced (eg, freezhg) 25 temperatures. The light cover/difuser 110 is designed to enclose at least one light source L, where the or each light source L may be an incandescent globe, fluorescent tube, dichroic globe, LED or the like. (In practice, within a very large cabinet, a plurality of, eg., fluorescent tubes, will be provided at 30 spaced intervals to ensure the interior of the cabinet (and the articles therein) 6 are appropriately (and attractively) illuminated. The light cover/diffuser 110 has an inner shell 120 and an outer shell 130, both formed from light transmitting materials such as plastics or glass. Suitable plastics include perspex, acrylics, and PTFE, which can be 5 formed to the desired shapes by, eg., heating and folding. The inner shell 120 is of substantially top-hat" section in end view with side walls 121 and 122 interconnected by a top wall 123, where the side walls 121122 having aligned outwardly-directed flanges 124, 125, The outer shell 130 is of substantially "C'"shape, with side walls 10 131, 132 interconnected by a top wall 133, where the side walls 131, 132 have inwardly-directed flanges 134, 135. The height of the side walls 131 132 of the outer she 130 exceeds the height of the side walls 121, 122 of the inner shell 120 so that the top walls 123, 133 are spaced apart when the inner and outer shells 120, 130 are assembled together with their flanges 15 124, 125, 134, 135 arranged in overlapping arrangement to form the substantially U-shaped air gap 140 therebetween. The overlapping pairs of flanges 124, 134 and 125 135 may be fixed together, eg., by suitable adhesives, giues or mechanical fasteners; and the light cover/diffuser 110 may be releasably secured to the body of the 20 cabinet (not shown) by suitable mounting means eg. clips/mechanical fasteners, to enable the light cover/diffuser 110 to be removed to enable any or all of the light sources L to be serviced, eg. by way of replacement. As illustrated in FIG. 7, the inner shell 120 defines an elongate space 150in which the light sources L are received. 25 In this embodiment, the respective ends of the light cover/ diffuser 10 are open, although they may be sealed to adjacent wall portions of the cabinet (not shown) by suitable sealing materials, eg., rubber or plastic gaskets, and/or sealant materials (eg., silicone sealants). In an alternative embodiment, not illustrated, end caps or plugs 30 may be inserted into the ends of the light cover/diffuser 110; or the 7 respective ends of the inner and/or outer she's 120,130 may be formed with end walls to sealably close the air gap 140, As illustrated in FIG. 10, the light cover/diffuser 210 of a third embodiment has inner and outer shells 22, 230 of similar configuration to 5 the shells 120,130 of the light cover/diffuser of the second embodiment; but one or more spacers 260 may be provided, eg., at regular intervals, between the top walls 223, 233 of the shells 220, 230. The spacers 260 may be formed integrally with one or both of the top wails 223, 233; or may be separate thereto. If formed separately, the 10 spacers 260 may be of metal, plastics or timber materials, and may or may not contain dessicant materials (such as silica ge). In the embodiment illustrated in FIG. 10, the spacer 260 is not transparent; but the spacer 260 may be formed of transparent material if preferred, 15 Referring now to FIG 11, the light cover/diffuser 310 of the fourth embodiment has an inner shell 320 and an outer she 330 substantially as hereinbefore described, where an intermediate shell 370, of modified "top hat" section is interposed therebetween so that two air gaps 340 are defined within the light cover/diffuser 310. 20 11i this embodiment, a pair of spacers 360 are provided within the light cover/diffuser 310 in the manner of the spacer 260 hereinbefore described. The provision of the two air gaps 340 defined by the three shells 310, 370, 330 wil minimize the flow of heat energy from the space 350 25 containing the light sources (not shown) to the interior of the cabinet. In the fifth embodiment lustrated in FIG. 12, sealing spacers 460 are provided between adjacent pairs of side walls 421, 471; 471, 431; 422, 472; and 472, 432 of the shells 420, 470, 430 in the light cover diffuser 410. 30 The light cover/diffuser 410 has a pair of air gaps 440 and 8 spacers 460 in the manner hereinbefore described with reference to light cover/diffuser 410 of the fourth embodiment, As hereinbefore described, the light covers/diffusers 10, 10A, 110, 210, 310, 410 may be used in refrigerated cabinets forfood, but may be 5 used in other controlled or ambient environmental applications such as freezers. The overall dimensions (eg., size and shape) of the light cover/diffusers, and the air gaps provided therein. may be varied to suit the particular intended applications. 10 As hereinbefore described, the air gaps may be open at the ends of the shells, or the ends may be sealed; and the air gaps may be filled with one or more other gases, or be partially evacuated, to enhance the efficiency thereof, Also, as hereinbefore described, the perimeters of the light 15 covers/diffusers may be sealed, eg., to the cabinets, with sealing devices or suitable sealants. Spacers may be provided in the air gaps and may be manufactured from transparent or opaque materials. Breather or ventilation holes may be provided through the walls 20 of any or all of the shells, but preferably, the breather or ventilation holes in one shell will not be aligned with the breather or ventilation holes in an adjacent sheit to prevent a direct flow of air therethrough In the embodiments llustrated, one or two air gaps have been provided, but the number of air gaps may be increased by providing 25 additional shells. Usually, the increasing number of air gaps and shells will minimise the flow of heat energy from the eight sources L to the interior of the cabinets to which the light covers/diffusers are fitted. Typically, the shells are formed from clear or translucent plastics, eg., perspex, acrylics, PTFE, or glass, but they may be formed from 30 other transparent or light transmitting materials, preferably such materials 9 being provided in sheets and easily bendable, eg, by the application of localised heating to enable the light covers/diffusers to be formed to the desired shapes. Coatings may be applied to the materials of the shells; and 5 semi-transparent and/or opaque layers may be applied thereto, eg as masks, to generate colours/patterns/designs/trade marks or other indicia or aesthetic effects on the articles being displayed. One or more reflectors may be provided within the light covers diffusers; and one or more light reflectors may be provided behind the light 10 sources, ie., in the spaces 150, 350, on the opposite side thereof to the air gaps. The present invention provides a simple, yet efficient, means of minimising heat transfer from the light sources to the interior of the cabinets or other equipment in which the light covers/diffusers may be fitted. 15 Indeed, the heat trapped in the spaces containing the light sources L can be directed to the external faxcia of the cabinet to provide anti-sweat heating, obviating the need for electric anti-sweat heaters; furher minimising the power input for the cabinet (while still achieving much improved lighting). 20 Various changes and modifications may be made to the embodiments described and illustrated without departing from the present invention.

Claims

1. A refrigerator or freezer cabinet, suitable for foodstuffs, including: a frame, with top and bottom rails at the front of the frame interconnected by vertical centre- or end mullions; 5 at least metal-framed glass door hinged on one of the end mullions and engageable with one of the centre mullions at least one substantially U-shaped light cover/diffuser, having spaced legs, mounted on at least one of the mullions and extending within the interior of the refrigerator or freezer cabinet; 10 an elongate space defined by the at least one mullion and the light cover / diffuser; and at least one light source in the elongate space; the light cover / diffuser including: a first layer or shell of clear or translucent material forming the 15 elongate space with the mullion; a second layer or shell of clear or translucent material, connected to the first layer or shell, and spaced therefrom; and an air gap defined between the first and second layers or shells on at least one side of the first layer or shell opposed to the elongate space; 20 the light cover / diffuser being operable to minimise transfer of heat energy from the light source to the interior of the refrigerator or freezer cabinet.

2. The refrigerator or freezer cabinet as claimed in Claim 1, 25 wherein: third or subsequent layers or shells of clear or translucent material are connected to preceding layers or shells to define respective air gaps therebetween in the direction away from the space. 2039584v1 11

3. The refrigerator or freezer cabinet as claimed in Claim 1 or Claim 2, wherein: the adjacent ends of the first, second and subsequent layers are sealed or open. 5

4. The refrigerator or freezer cabinet as claimed in any one of Claims 1 to 3, wherein: the, or each, air gap may contain air and/or other gases, and is at least partially evacuated.

5. The refrigerator or freezer cabinet as claimed in any one of 10 Claims 1 to 4, wherein: one or more spaces are formed as part of the layers or shells, or be interposed between the layers or shells, to create/maintain the air gap(s) between the layers or shells.

6. The refrigerator or freezer cabinet as claimed in any one of 15 Claims 1 to 5, wherein: the layers or shells are formed of clear or translucent materials such as plastics or glass or other suitable transparent or light transmitting materials; and layer(s) of semi-transparent or opaque materials are optionally applied to the layers or shells, as masks, to create colours/patterns/designs/ 20 trade marks/other aesthetic effects, or the like.

7. The refrigerator or freezer cabinet as claimed in any one of claims 1 to 6, wherein: at least one cover strip, of non-transparent material, is fixed to the mullion and extends over a portion of the second, or outer, layer or shell 25 to hide a joint line between the mullion and the light cover / diffuser.

8. The refrigerator or freezer cabinet as claimed in claim 7, wherein: fasteners secure the legs of the light cover / diffuser to the 2039584v1 12 mullion, the cover strips providing the mounting means for the light cover / diffuser.

9. The refrigerator or freezer cabinet as claimed in any one of claims 1 to 8, wherein: 5 at least one reflector, directed towards the light source, is provided in the air space. 2039584v1