Abstract:
A mullion-less door system for refrigerated display cabinets, chillers, cold rooms or freezers, incorporates offset seal members on the respective vertical stiles of adjacent doors, to form a labyrinth seal or gasket between the doors, while still allowing free operation of each, and without requiring indirect sealing via door mullions of the cabinet body or frame. Secondary seal members, incorporating magnetic gaskets, seal the top and bottom rails of the peripheral door frames, supporting transparent door panes, to the adjacent cabinet body or frame portions. Lighting assemblies may be incorporated in the vertical stiles to illuminate the contents of the cabinets; and the hinge assemblies may incorporate self-closing mechanisms for the doors.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    This invention relates to a door system for refrigerated display cabinets. 
         [0003]    The invention is particularly suitable for, but not limited to, a mullion-less door system for refrigerated display cabinets; but may also be used for other controlled- or ambient-environmental applications, including chillers and freezers, for the storage of foods or other articles. 
         [0004]    Throughout the specification, the term “refrigerated display cabinets” shall be used to include (i) refrigerated cabinets, chillers and freezers of the types for the display of the refrigerated products typically sold in upright multi-level display refrigerators and freezer cases at supermarkets, grocery shops, fuel outlets, bottle shops, butcher shops, fruit shops, pet-food shops and the like, together with (ii) all other types of refrigerated cabinets and freezers for the (retail or wholesale) display and/or storage of foods or other articles. 
         [0005]    2. Prior Art 
         [0006]    Refrigerated products, including fresh and frozen foods, are typically displayed in open display cabinets; or behind glass doors, either mounted on refrigerated display cabinets, or providing consumer access to controlled-environment rooms or spaces. 
         [0007]    Typically, these display cabinets can extend along the whole, or part of, the length of the aisles and/or walls in the supermarkets, shops or other retail or wholesale outlets. 
         [0008]    The open display cabinets are not as energy efficient as the display cabinets using glass doors, as heat is drawn from the adjacent environment; but there is a resistance by many retailers to use the display cabinets having the glass doors, as these retailers believe the glass doors act as a “barrier” to their customers, resulting in reduced sales. Many of the retailers prefer the “open look” of the door-less open display cabinets; but are seeking energy efficient alternatives thereto. 
         [0009]    While glass doors maybe retrofitted to existing open display cabinets, many retailers are concerned by the disruption to trading due to the complicated installation procedures. 
         [0010]    The glass-door display cabinets typically have a mullion between each adjacent pair of doors; where the, or each, mullion typically houses at least one vertical light and protective cover(s) therefore, all of which protrude rearwardly into the refrigerated space; further impeding a clear view, to the consumers, of the products displayed within the display cabinets, when viewed looking along the length of the display. 
         [0011]    The mullions are typically arranged to provide the surfaces of the cabinets against which the door seals (e.g. of a flexible gasket/seal type) provides sealing engagement between each door and its respective mullion. 
         [0012]    The retailers must consider the balance between: 
         [0013]    (i) the potential loss of sales by the fitting of glass doors to the open display cabinets; against: 
         [0014]    (ii) the reduced size and operational requirements (including the reduced electricity (or other input energy) consumption) for the refrigerating/freezer units used to maintain the desired temperatures within the display cabinets fitted with doors, where the provision of the doors minimizes the ingress of heat from the surrounding environment into the display cabinets. 
         [0015]    In addition, particularly with fresh fruit and vegetables, the air temperature and humidity within the display cabinets must be maintained within strict control limits to ensure maximum shelf life of the fresh foods. 
       SUMMARY OF THE PRESENT INVENTION 
       [0016]    It is an object of the present invention to provide a door system for refrigerated display cabinets (as hereinbefore defined) which is suitable for “retro-fitting” to existing open display cabinets and/or for installation in new refrigerated display cabinets. 
         [0017]    It is a preferred object of the present invention to provide such a door system which seeks to minimize as many obstructions to the clear view, by consumers, of the products displayed within the refrigerated display cabinets, while still maintaining a high degree of thermal efficiency. 
         [0018]    It is a further preferred object of the present invention to provide such a door system which may incorporate features such as self closing doors, effective minimization of cold air losses, an effective illumination of their display products, door-opening devices, ease of operation and/or ease of installation. 
         [0019]    Other preferred objects of the present invention will become apparent from the following description: 
         [0020]    In one aspect, the present invention resides in a mullion-less door system for a refrigerated display cabinet including: 
         [0021]    at least one door, the or each door having at least one transparent pane surrounded by a peripheral door frame having a pair of vertical stiles; 
         [0022]    respective upper and lower hinge members incorporated in, or mountable on, respective top and bottom rails of the peripheral frame, located at or adjacent one of the vertical stiles of the door, when in use; and 
         [0023]    at least one seal member, is mounted on, or fixed to, one of the vertical stiles for sealing engagement with the other of the vertical stiles of an adjacent similar door and/or an adjacent body or frame portion of the refrigerated display cabinet. 
         [0024]    Preferably, a second such seal member is mounted on, or fixed to, the other of the vertical stiles of the door for sealing engagement with the one vertical stile of a second adjacent similar door and/or another adjacent body or frame portion of the refrigerated display cabinet. 
         [0025]    Preferably, the seal members on respective adjacent vertical stiles of the door and the adjacent similar doors are arranged to form of a flexible labyrinth seal or gasket between the doors. 
         [0026]    Preferably, the seal members on the adjacent vertical stiles are offset, so as to not impede the operation of the doors, to allow the doors to open and close with minimal friction and effort, while minimising air leaks between the adjacent doors when both doors are closed. 
         [0027]    Preferably, one or more secondary seal members extend at least partially around each peripheral frame, for sealing engagement of the door, when closed, to adjacent door and/or adjacent cabinet body or frame portions 
         [0028]    Preferably, the secondary seal members along the top and bottom rails of the peripheral frame are, or incorporate, magnetic gaskets, which co-operate with the adjacent cabinet body or frame portions to improve the seal there-between. 
         [0029]    Preferably, the, or each, transparent pane may be of single- or multi-layered glass; single or multi-layered plastic; combinations of glass and plastic; or of other suitable materials. 
         [0030]    Preferably, the peripheral frame for the, or each, glass door is of metal such as aluminium or stainless steel); plastics; fiberglass or composite materials; or a combination of two or more of these materials. 
         [0031]    Preferably, at least one of the vertical stiles of the peripheral frame incorporates one or more light assemblies, with LED(s) being preferred for their compactness &amp; low heat emission. The, or each, light assembly may be connected to a door switch, which de-energizes one or more of the light assemblies, when the respective door is opened. 
         [0032]    The upper and lower hinge members may incorporate sockets, bushes or other formations to receive respective hinge pins mounted in, or on, the adjacent cabinet body or frame portions; where the hinge pins may be mounted thereto by suitable brackets or sub-frames. Alternatively, the hinge pins may extend from the peripheral door frame, to be received in complementary sockets, bushes or other complementary formations, in or on, adjacent cabinet body or frame portions. 
         [0033]    Preferably, each peripheral frame has at least one handle, attached to, or integral with, one of the vertical stile of the peripheral door frame. 
         [0034]    Preferably, the, or each, seal member is formed of resilient, flexible material, such as natural- or synthetic rubber(s); plastics; or a combination of two or more of these materials; and the seal member(s) may be single- or multi-layered. 
         [0035]    The, or each, door may be closed by a respective self-closing unit, which may include a self-loading torsion spring, and/or one or more cams installed over the (preferably lower) hinge pin(s). 
         [0036]    In a second aspect, the present invention resides in a refrigerated display cabinet incorporating the mullion-less door system hereinbefore described. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0037]    To enable the invention to be fully understood, the preferred embodiments will now be described with reference to the accompanying drawings, in which: 
           [0038]      FIG. 1  is front elevation view of a refrigerated display cabinet before the fitment of the doors in accordance with the present invention; 
           [0039]      FIG. 2  is a similar view of a refrigerated display cabinet after the doors have been fitted; 
           [0040]      FIG. 3  is a similar view of the refrigerated display cabinet fitted with one door of the present invention; 
           [0041]      FIG. 4  is a top plan view illustrating one sealing arrangement between an adjacent pair of one embodiment of the doors; 
           [0042]      FIGS. 5 &amp; 6  are respective front and rear elevational views of the one embodiment of the doors; 
           [0043]      FIG. 7  is a front elavational view of a second embodiment of the doors; 
           [0044]      FIG. 8  is a perspective, part-sectional, view, of a top hinge assembly for the doors; 
           [0045]      FIG. 9  is a perspective, part-sectional, view of a torsion-bar closer for use with the doors; 
           [0046]      FIG. 10  is a top plan view of a second sealing arrangement between an adjacent pair of the second embodiment of the doors; and 
           [0047]      FIG. 11  is a perspective view of a cam closer suitable for use with the doors. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0048]    Referring to a first embodiment illustrated in  FIG. 1  of the drawings, the refrigerated display cabinet  10  has a body  11 , typically of sheet metal/expanded polystyrene foam (and/or other insulation foam)/sheet metal construction. One or both of the metal skins can be manufactured from stainless steel; or one or both of the sheet metal skins may be manufactured from sheet steel or aluminium, where the exposed face of the or each metal skin is provided with a suitable protective and/or ascetically-appealing coated finish. 
         [0049]    At the front of the cabinet body  11 , a mullion-less cabinet frame  12  is provided within the display cabinet  10 , to enable the mounting of the door system, in accordance with the present invention, to be hereinafter descried. 
         [0050]    The cabinet frame  12  has, in this embodiment, top and bottom (horizontal) frame members  13 ,  14 , interconnected by a pair of vertical end members  15 ,  16 , but not by door mullions. 
         [0051]    A plurality of shelves  17 , in this example being four (4) in number, are provided within the cabinet body  11 , and may be vertically adjustable to enable the number of shelves  17  and/or the vertical spacings there-between to be varied. 
         [0052]    NB: The skilled addressee will appreciate that different numbers of shelves  17 , and the vertical spacing&#39;s there-between, may be provided along the length of the cabinet body  11  to provide the best display configuration for the different products (e.g. fresh fruit and vegetables, dairy products, meats and the like) being stored and displayed in the display cabinet  10 . 
         [0053]      FIG. 2  illustrates a similar view of the refrigerated display cabinet  10  where, in this example, four (4) doors  20 ,  120  (in accordance with the present invention) have been fitted to the cabinet frame  12 , and where the spaces between adjacent pairs of doors  20 ,  120  are sealed by sealing members  40 ,  140  to be hereinafter described in more detail with reference to  FIGS. 4 and 10 . 
         [0054]    In the second embodiment of the refrigerated display cabinet  110 , illustrated in  FIG. 3 , the cabinet frame  112  has continuous top and bottom frame members  113 ,  114  which are not connect by vertical end members or by door mullions. This embodiment may be preferred where the display cabinet  10 A is to extend along the full length of a wall interconnecting a pair of spaced walls; or where the door system (in accordance with the present invention) is to be installed in a cold room (e.g. for alcoholic beverages), where the products on any of the shelves may be viewed and accessed by consumers either from inside or outside the cold room. 
         [0055]    As illustrated in  FIGS. 5 and 6  and  FIG. 7 , respective doors  20 ,  120  for the door system of the present invention maybe have “standard width” peripheral frames  21 , as in  FIGS. 5 and 6 ; or “slim-line” peripheral frames  121  with slim vertical stiles. 
         [0056]    The doors  20 ,  120  have a transparent pane  22 ,  122  e.g. of single-or-multi-layered glass, single-or-multi- layered plastics materials; or a multi layered glass/plastics combination; where the multi- layers are preferably separated by an air-gap or vacuum-gap to minimise heat transfer to the interior of the display cabinets  10 ,  110 . 
         [0057]    The peripheral frame  21 ,  121  for each door  20 ,  120  has first and second vertical stiles  23 ,  123  and  24 ,  124  interconnected by top and bottom rails  25 ,  125  and  26 ,  126 ; and may be formed from metal, plastic, fibreglass or composite construction; or a combination of two or more of these materials (e.g. a pair of stainless steel or aluminum extrusions which are interlocked together). 
         [0058]    A plurality of LED(s)  30 , or other light fittings, may be recessed in the rear face of one or both of the vertical stiles  23 ,  24 ,  123 ,  124  to illuminate the interior of the display cabinet  10 ,  10 A when the doors  20 ,  120  are closed. 
         [0059]    Each door  20 ,  120  maybe be connected to a door switch (not shown) which will de-energize the LED&#39;s or lights  30  when the respective doors  20 ,  120  are open. 
         [0060]    By locating the interior lighting for the display cabinets  10 ,  110  within the vertical stiles  23 ,  24 ,  123 ,  124 , all of the generated light is directed into the display cabinets; and additional light housings, potentially restricting the view into the display cabinets, are not required 
         [0061]    Referring to  FIG. 4 , magnetic gaskets  41 ,  42  are provided along the top and bottom rails  25 ,  26  of the peripheral frame  21  of each door  20  and are operable to engage the top and bottom frame members  13 ,  14  of the cabinet frame  12  when the doors  20  are closed. The magnetic characteristics of the magnetic gaskets  41 ,  42  can assist in fully closing the doors  20  and provide an increased effectiveness in the sealing between the doors  20  and the cabinet frame  12 . 
         [0062]    The first and second vertical stiles  23 ,  24  are provided with respective, substantially U-shaped, seal members  43 ,  44 , typically extruded from natural-or-synthetic rubber and/ or plastics-material, where the seal member  43  on the first vertical stile  23  is rearwardly offset relative to the centre line of the peripheral frame  21 , and so lies behind the complementary seal member  44  on the second vertical stile  24  of an adjacent door  20 , to create a flexible labyrinth gasket  45 , producing an effective sealing arrangement against air leakage between the adjacent pair of doors  20 . 
         [0063]    The skilled addressee will appreciate that the door seals  43 ,  44  of the adjacent doors  20  are designed to seal against each other and there are no vertical door mullions to providing indirect sealing between the adjacent doors  20 . 
         [0064]    By producing the seal members  43 ,  44  of a flexible material, such as natural-or-synthetic-rubber, plastics, and/or combinations thereof, the seal members  43 ,  44  will minimize air leaks between the adjacent doors  20 , while allowing the respective doors  20  to open and close with minimal friction and effort. 
         [0065]    To open the hingedly mounted doors  20 , at least one handle  50  is provided on, or formed integrally with, the second vertical stile  24  of the peripheral frame  21  of each door  20 , where the handle  50  may be of partial-or-full height of the door  20 . 
         [0066]    In the embodiments illustrated in the drawings, the doors  20 ,  120  are pivotally mounted to the top and bottom frame members  13 ,  13 A,  14 ,  14 A of the cabinet frame  12 ,  12 A, about pivotal axes at or adjacent the first vertical stile  23 ,  123  of each peripheral frame  21 ,  121 . (It will be appreciated by the skilled addressee that the pivotal axes may be moved towards the central vertical axis of each door  20 ,  120 , so that when the door is opened the first vertical stile  23 ,  123  swings inwardly into the interior of the display cabinet  10 ,  10 A thereby reducing the distance the doors  20 ,  120  swing outwardly in front of the display cabinet  10 ,  10 A. 
         [0067]    A respective socket or collar  27 ,  127 ,  28 ,  128  is provided in the top and bottom rails  25 ,  125 ,  26 ,  126  of the peripheral frames  21 ,  121  to receive the pivot pins of top and bottom hinge assemblies  60 ,  70 ,  170  to be hereinafter described with reference to  FIGS. 8 ,  9  and  11 , fitted to the top and bottom frame members  13 ,  113 ,  14 ,  114  of the cabinet frames  12 ,  112 . 
         [0068]      FIG. 8  illustrates a top hinge assembly  60  for the doors  20 ,  120 . 
         [0069]    The hinge assembly  60  has a base  61  fixed to the top frame member  13 ,  113  and has a vertical pivot pin  62  depending therefrom. The pivot pin  62  is rotatably received in the tubular collar or socket  27 ,  127  of the top rail  25 ,  125  of the door frame  21 ,  121 , adjacent the first vertical stile  23 ,  123 . 
         [0070]      FIG. 9  illustrates a bottom hinge assembly  70  for the doors  20 ,  120 , which incorporates a torsion-bar closer. 
         [0071]    The bottom hinge assembly  70  has a body  71  located in a recess  72  in a base plate  73  fixed to the bottom frame member  14 ,  114  by screw-fasteners  74 . A pivot pin  75  extends upwardly from the body  71  and is received in the socket or bore in the bottom rail  26 ,  126  of the peripheral door frame  21 ,  121 . 
         [0072]    A torsion bar  76  has a hook-member  77  releasably anchored in a diametrical bore  78  through the pivot pin  75 , and its upper end is non-rotatably received in an insert  79  received in the first vertical stile  23 ,  123 . 
         [0073]    When the door  20 ,  120  is moved away from its closed position, the torsion bar  76  is “twisted” along its length, and urges the door  20 ,  120  to towards the closed position when released. 
         [0074]    The torsion bar closer can be fitted within even the “thin” peripheral door frame  121  of door  120 . 
         [0075]      FIG. 10  illustrates a second embodiment of the sealing members forming the labyrinth sealing gasket or seal  145  between adjacent doors  20 ,  120 . 
         [0076]    The seal members  143 ,  144  can be manufactured, typically by extrusion, in a single configuration which is used in a mirror-image arrangement. Seal member  143  will only be described. 
         [0077]    Seal member  143  has a body  190  with a pair of spaced formations  191 ,  192  respectively received in complementary grooves or recesses in the vertical stiles  23 ,  24 ,  123 ,  124 . A first “lip”  193  extends from the body  190  adjacent a side edge thereof; while a second “lip” extends from the body  190  intermediate its length, and configured to overlap the second “lip” of the seal member  144  on the adjacent door  20 ,  120 . 
         [0078]    The distal ends of the “lips”  193 ,  194  of the seal member  143  are in sealing contact with the body  190  of the seal member  144 ; and vice versa. 
         [0079]    As with the seal members  43 ,  44  illustrated in  FIG. 4 , the labyrinth seal  145  provides effective sealing between the doors  20 ,  120  when closed, without requiring a door mullion to ensure effective sealing between the doors. 
         [0080]    As illustrated in  FIG. 11 , an alternative bottom hinge assembly  170 , incorporating a cam-type closer, for self-closing of the doors  20 ,  120  may be provided at the bottom of each door  20 ,  120  where a lower cam member  171  is formed integrally with, or mounted in non-rotational relationship to, the lower pivot pin  161 . The lower cam member  171  has an inclined-cam sector  172  and a substantially horizontal “closed position” sector  173 . These sectors  172 ,  173  are respectively engagable by complimentary inclined-cam and “closed position” sectors  174 ,  175  on an upper cam member  176 , co-axial with the adjacent socket or bush  28  on the bottom rail  26 ,  126  of the peripheral frame  21 ,  121  of the door  20 ,  120  and operable to rotate with the bottom rail  26 ,  126  and incorporates a bore with a clearance to co-axially receive the lower hinge pin  160 . 
         [0081]    When the door  20 ,  120  is closed, the respective inclined-cam and “closed position” sectors  172 ,  174  and  173 ,  175  of the lower and upper cam members  171 ,  176  are in respective “face-to-face” engagement. However, as the door  20 ,  120  is moved to the open position, the inclined-cam sector  174  of the upper cam member  176  “rides” up the inclined-cam sector  172  of the lower cam member  171  to thereby raise the door  20 ,  120  a small distance relative to the bottom frame member  14 ,  114  of the cabinet frame  12 ,  112 . 
         [0082]    When the door handle  50 ,  150  is released, gravity causes the inclined-cam sector  174  of the upper cam member  176  to move downwardly until the door  20 ,  120  is closed, and the respective pairs of sectors  172 ,  173 ,  174 ,  175  occupy their initial positions. 
         [0083]    As particularly illustrated in  FIGS. 2 and 3 , the skilled addressee will appreciate that the present invention, by omitting the mullions and employing the door system of the present invention, a maximum viewing area is available, for the viewing of the goods within the display cabinet  10 ,  110  when the doors  20 ,  120  are closed, compared to existing refrigerated display cabinets which incorporate door mullions to enable sealing between adjacent pairs of doors. 
         [0084]    In addition, by recessing the lighting assemblies  30  into the rear faces of the vertical stiles  23 ,  24 ,  123 ,  124  of the peripheral frames  21 ,  121 ; and more particularly, if light assemblies  30  such as LED&#39;s are selected which do not require clear cover panels; then the effective obstruction to the viewing of the contents of the display cabinets  10 ,  110  by the doors  20 ,  120  is further reduced. 
         [0085]    In addition, the arrangement of the sealing members  40 ,  140  on the doors  201   120 , as illustrated in  FIGS. 4 and 10 , provides a high level of sealing efficiency between adjacent pairs of doors  20 ,  120  when closed, whilst still allowing the doors  20 ,  120  to be easily opened and closed. 
         [0086]    The skilled addressee will appreciate that the present invention provides a highly effective door system for refrigerated display cabinets  10 ,  110 , where the disadvantages of existing-type door mullions are overcome; and where the invention can be applied to both existing refrigerated display cabinets, by way of “retro-fitted” installations; or as “original equipment manufacture” (OEM) in new refrigerated display cabinets. 
         [0087]    Various changes and modifications may be made to the embodiments described and illustrated without departing from the present invention.