Abstract:
A heated food storage and display cabinet comprises an open fronted enclosed chamber within which packs of food can be stored, the cabinet including flow inducing means and heater means arranged in an upper region thereof, the flow inducing means being operable to draw air from an upper portion of the enclosed chamber, direct the air over the heater means to heat the air and subsequently urge the heated air down the rear wall of the chamber and across the floor of the chamber towards the open front of the chamber, said heated air being subsequently directed upwardly and rearwardly across the open front of the chamber by an airflow direction member of the chamber to provide a heated air curtain across the open front of the chamber, wherein a portion of the heated air passes into the chamber as said heated air moves down the rear wall and across the floor so as to pass over and around packs of food stored therein.

Description:
RELATED APPLICATION DATA 
       [0001]    This application is a continuation of U.S. Nonprovisional patent application Ser. No. 11/911,885, filed Oct. 18, 2007; which is a §371 application of International Application No. PCT/GB2006/001469 filed Apr. 21, 2006, and which claims priority to GB50508204.5, filed Apr. 22, 2005. Each of these applications is incorporated herein by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to a heated food storage and display cabinet and is primarily concerned with a heated food storage and display cabinet for use in supermarkets, and mixed purpose retail outlets, such as convenience stores, where heated food is made available for purchase. 
       BACKGROUND 
       [0003]    Changes in working patterns have lead to changes in eating habits, particularly with respect to what might be called traditional meal times where a family group sits around a table and eats home cooked food. It is now becoming increasingly commonplace for convenience meals to be eaten of an evening while watching television from an easy chair. This change has, in turn, lead to an increase in takeaway food outlets where a person can collect a pre-cooked meal or constituent portion to eat at home or on the move. 
         [0004]    For some time now, supermarkets have offered a range of prepared food which can be taken home, heated or cooked, and then eaten. However, there is now increasing competition from takeaway food outlets which supermarkets wish to address by supplying hot ready cooked meals and snack items themselves. One of the problems faced by supermarkets is how to keep such food hot whilst making it readily accessible to customers and it is an object of the present invention to provide a cabinet which will be suitable for this purpose. A further object of the present invention is to provide a heated food storage cabinet which enables heated air to flow over packs of food contained therein. 
         [0005]    According to the present invention there is provided a heated food storage and display cabinet comprising an open fronted enclosed chamber within which packs of food can be stored, the cabinet including flow inducing means and heater means arranged in an upper region thereof, the flow inducing means being operable to draw air from an upper portion of the enclosed chamber, direct the air over the heater means to heat the air and subsequently urge the heated air down the rear wall of the chamber and across the floor of the chamber towards the open front of the chamber, said heated air being subsequently directed upwardly and rearwardly across the open front of the chamber by an airflow direction member of the chamber to provide a heated air curtain across the open front of the chamber, wherein a portion of the heated air passes into the chamber as said heated air moves down the rear wall and across the floor so as to pass over and around packs of food stored therein. 
         [0006]    The airflow direction member of the cabinet ensures that the flow of heated air driven by the flow inducing means is not ejected out through the open front of the cabinet. The airflow redirection member preferably extends across the cabinet between opposing side walls of the cabinet. The airflow redirection member is preferably planar and is inclined inwardly with respect to the chamber. The airflow redirection member may be inclined inwardly with respect to the chamber at an angle of between 10 to 20 degrees to the vertical. Preferably, the airflow redirection member is inclined ant an angle of around 15 degrees to the vertical. 
         [0007]    The flow inducing means preferably comprise a pair of fans situated in an upper portion of the chamber. The fans are preferably provided in a side by side arrangement. The heater means are positioned at the fan outlets. The heater means may preferably comprise one or more electric heating elements. The fans are operable independently of one another and as such may be operated at slightly different speeds so as to ensure a uniform distribution of air around the cabinet. 
         [0008]    In a preferred embodiment the fans and heater means are provided in a fan chamber situated in an upper portion of the cabinet chamber. The fan chamber is provided with an inlet arranged to receive air from within the open fronted enclosed chamber of the cabinet and an outlet arranged to direct heated air towards the rear wall of the enclosed chamber. The inlet may comprise a plurality of apertures aligned with the inlet to the fans. The apertures may comprise a plurality of louvered slots. The fan chamber may be separated from the cabinet chamber by a panel extending between opposed sides of the cabinet chamber. The panel is preferably movable so a to permit access to the fan chamber. The panel may be hinged to the cabinet. 
         [0009]    The cabinet chamber is preferably provided with one or more food pack support means. The food pack support means may comprise one or more shelves. Each shelf may comprise a pair of spaced brackets having a food pack support member extending therebetween. The support member may be provided with a apertures therethrough. In a preferred embodiment the support member may be inclinable. As such the support member may be set at desired inclination. The support member is preferably provided with an airflow redirection means along its forward edge. The airflow redirection means may be defined by a tab or curved surface extending along the forward edge of the support member. The airflow redirection means may be incorporated into a display member provided on the forward edge of the support member. 
         [0010]    According to a further aspect of the present invention there is provided a method of storing and displaying heated food in an open fronted cabinet, the method comprising providing an open fronted enclosed chamber within which packs of food can be stored, providing flow inducing means and heater means arranged in an upper region thereof, operating said the flow inducing means to draw air from an upper portion of the enclosed chamber, direct the air over the heater means to heat the air and subsequently urge the heated air down the rear wall of the chamber and across the floor of the chamber towards the open front of the chamber, providing an airflow direction member to direct said heated air upwardly and rearwardly across the open front of the chamber to provide a heated air curtain across the open front of the chamber, and causing a portion of the heated air to pass into the chamber as said heated air moves down the rear wall and across the floor so as to pass over and around packs of food stored therein. 
       SUMMARY OF THE DISCLOSURE 
       [0011]    In one implementation, the present disclosure is directed to a method of storing and displaying heated food in an open fronted cabinet. The method includes: providing a chamber within which packs of food can be stored, the chamber having an upper portion, a lower portion, a rear wall and an open front; drawing air from the upper portion of the chamber; heating the air with a heating element disposed above the chamber; urging the heated air from the upper portion to the lower portion of the chamber with a flow inducer along the rear wall; moving the heated air across the lower portion of the chamber towards an inwardly angled lip mounted proximate the open front; and redirecting the heated air upwardly and rearwardly across the open front so as to provide a heated air curtain across the open front. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    For the purpose of illustrating the invention, the drawings show aspects of one or more embodiments of the invention. However, it should be understood that the present invention is not limited to the precise arrangements and instrumentalities shown in the drawings, wherein: 
           [0013]      FIG. 1  shows a front view of a cabinet according to the present invention; 
           [0014]      FIG. 2  shows a cross-sectional side view if the cabinet of  FIG. 1  as indicated by arrows A-A of  FIG. 1 ; 
           [0015]      FIG. 3  shows an exploded view of the fan and heater arrangement of the cabinet; 
           [0016]      FIG. 4  shows a side view of the heater arrangement of  FIG. 3 ; 
           [0017]      FIG. 5  shows an exploded view of a shelf of the cabinet; 
           [0018]      FIG. 6  shows a partial perspective view of a shelf bracket; and 
           [0019]      FIG. 7  shows a side view of a shelf ticket strip. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    Referring firstly to  FIGS. 1 and 2  there is shown a cabinet generally designated  10 . The cabinet  10  comprises a base portion  12  and a product display portion  14  above the base portion  12 . The cabinet  10  includes a floor  16 , a rear wall  18 , opposed side walls  20 , a base wall  22  and a top wall  24  and a front wall  26 . The base and product display portions  12 ,  14  are delimited by the base wall  22  such that the base portion  12  is defined by the floor  16 , the base wall  22  and lower portions of the rear wall  18   a , side walls  20   a  and front wall  26   a . The walls  18   a , 20   a , 22  and  26   a  and floor  16  of the base portion  12  define a substantially enclosed space  28  The product display portion  14  is defined base wall  22 , top wall  24  an upper portions of the rear wall  18   b , side walls  20   b  and front wall  26   b . The walls  18   b , 20   b , 22 , 24  and  26   b  of the product display portion  14  define partially enclosed space  30 , hereinafter referred to as the heated space  30 . The heated space  30  is accessible through the open front  32  of the cabinet  10  defined between the top wall  24 , and upper portions of the side and front walls  20   b ,  26   b . The upper portions of the side walls  20   b  are transparent and thus allow the interior of the heated space  30  to viewed from either side of the cabinet  10 . 
         [0021]    The underside of the floor  16  is provided with casters  34  to enable the cabinet  10  to be easily moved over the surface, such as the floor of a retail premises, upon which the cabinet  10  is provided. One or more of the casters  34  may be lockable so as to enable the cabinet  10  to remain at a desired location. The lower portion  26   a  of the front wall is provided with a bumper rail  36  which extends across the front of the cabinet  10 . The bumper rail  36  is provided to protect the cabinet from impact damage from, for example, shopping arts or other instore product transportation equipment. The bumper rail  36  also can be used as a handle when maneuvering the cabinet  10 . 
         [0022]    The heated space  30  is provided with shelves  38  which extend across the heated space  30  between the side walls  20 . Each shelf  38  comprises a pair of brackets  40  which are spanned by a product support member  42  formed from a substantially planer portion of plastic coated wire mesh. It will be appreciated that the product support members  42  may have configurations other than that of wire mesh, and the configuration of a given product support member  42  will depend at least in part in the nature of the food pack it is intended to support. For example, in an alternative configuration the support member  42  may be defined by sheet of metal provided with or without perforations. The brackets  40  are mounted to support members provided to the rear of the heated space  30 . The support members are positioned forward of the rear wall  18  of the cabinet  10  so that the rear edges of the bracket  40  and support members  42  are spaced from the rear wall  18 . 
         [0023]    hi the embodiment shown the cabinet  10  is provided with three shelves  38 . It will be appreciated that the cabinet  10  may be provided with a greater or lesser number of shelves  38  depending upon the size and nature of the food packages which the cabinet  10  is to receive and display. The base wall  22  is provided with a tray  44  upon which food packages may be placed. The tray  44  is positioned above the base wall  22  so as to provide a space  46  therebelow. The tray  44  is also perforated. 
         [0024]    In an upper part of the product display portion  14  there is provided a fan chamber  48  which is defined between the top wall  24 , the side walls  20  and a soffit panel  50 . Within the fan chamber  48  there are provided two blower fans  52  and a plurality of electric heater elements  54 . In the embodiment shown, the fans  52  are each double inlet blower fans. The soffit panel  50  is hinged to the cabinet  10  to permit easy access to the fans  52  and heater elements  54 . The fan chamber  48  is provided with inlets defined by a plurality of louvres  56  provided in an forward part of the soffit panel  50  and an outlet  58  which faces the top of the rear wall  18 . The heater elements  54  are arranged between the delivery outlet of the fans  52  and the chamber outlet  58  so as to heat air ejected from the fans  52 . 
         [0025]    The arrangement of the fans  52  and the heater elements  54  is illustrated in greater detail in  FIGS. 3 and 4 . The fans  52  are mounted in a side by side arrangement to a heater box  88 . The heater box  88  is provided with respective inlet apertures  90  to which the discharge outlets  92  of the fans  52 . The heater box is provided with an outlet  93  which corresponds to the aforementioned outlet  58  of the fan chamber  48 . Within the heater box  88  there is provided a mounting member  94  which supports the heater elements  54  in a staggered one up, two down array. The heater elements  54  extend substantially across the full width of the heater box  88 . The heater box  88  includes a floor  96  (not shown in  FIG. 3 ) and a two part lid  98 , 100 . In use, sealing means such as, for example, metallized tape is used to seal any small gaps around the edges of the lid  98 , 100 . The sealing of such gaps ensures that the vast majority of the air directed into the heater box  88  by the fans  52  passes over the heater elements  54  and out of the outlet  93 . 
         [0026]    The speed of each fan  52  is independently controllable via a dedicated voltage potentiometer. The speed of each fan  52  is independently controllable so as to ensure a uniform distribution of heated air is circulated around and within the heated space  30 . The scroll effect of the blades of each fan  52  has the effect of delivering air to the respective fan outlet which is directed slightly to one side. To counter the scroll effect each fan  52  may be operated a slightly different speed to the other. The fan voltage potentiometers also ensure that the airflow speed over the heater elements  54  is optimised so that the maximum amount of heat energy is transferred to the airstream. The optimised speed of the fans  52  is variable depending upon external ambient conditions. 
         [0027]    The heater elements  54  may comprise finned ceramic heaters having an output of between 500 and 2000 watts. Depending upon such factors as, for example, the ambient temperature surrounding the cabinet  10 , the initial temperature of the food products it is intended to place within the cabinet  10 , and the anticipated length of time for the food products on display, the heater elements may be operated such that a temperature within the heated space  30  of between 60 to 90 degrees Celsius is maintained. It will be appreciated that the thermal output of the heater elements  54  is related to the output airflow of the fans  52 . For example, the greater the airflow the higher the thermal output that may be required in order to provide a desired temperature within the heated space  30 . 
         [0028]    Operation of the cabinet  10  will now be described. In use, the fans  52  are operated to draw relatively cool air through the soffit panel louvres  56  and into the fan chamber  48  as indicated by arrows  60 . Upon initial start-up of the cabinet  10  it will be appreciated the air drawn into the fan chamber  48  is at ambient temperature, while during normal operation of the cabinet  10 , where heated air is circulated in the manner described below, the air will be at a temperature above that of ambient. The air is accelerated by the fans  52  and passes over the heating elements  54  before exiting the fan chamber  48  via the outlet  58 . The heated air stream subsequently impinges upon the rear wall  18  and is directed downwardly as indicated by arrows  62  along a path defined between the rear wall  18  and the rear of the shelf brackets  40 . As the heated air travels downwardly along the rear wall  18 , portions thereof split away and spill into the heated space  30  over and around the shelves  38  and over the tray  44  as indicated by arrows  64 . The natural tendency of the heated air to expand causes the aforementioned portions thereof to spill into the heated space  30 . The temperature of the heated air is at its greatest as it leaves the heater box  88  and enters the heated space  30 . By causing a portion of the heated air to spill into the heated space  30  as the heated air travels down the rear wall  18  it will be appreciated that the heat energy imparted to the air by the heater elements  54  is conveyed to the vicinity of food products within the heated space  30 . 
         [0029]    The remaining heated air, upon reaching the base wall  22  is directed through the space  46  under the tray  44  as indicated by arrows  66 . Due to the natural buoyancy of the heated air, small amounts thereof rise upwardly through the perforations of the tray  44  as indicated by arrows  68 . The remaining heated air subsequently reaches the front wall upper portion  26   b  whereupon it is redirected upwards and into the heated space  30 . A portion of this heated air is directed towards the louvres  56  so as to provide a heated air curtain extending between the front wall upper portion  26   b  and the louvres  56  as indicated by arrows  70 . The remainder of the heated air is directed towards the shelves  38  as indicated by arrows  72  whereupon it mixes with air spilling over and around the shelves from the airstream travelling down the rear wall  18  as indicated by arrows  74 . The air curtain  70  prevents relatively cool air, indicated by arrows  76 , which is external to the cabinet  10  from entering the heated space  30  and thereby lowering the temperature of the heated space  30 . 
         [0030]    The operation of the cabinet  10  may be considered to comprise the steps of compression of cooler air by the fans  52 , heating of the compressed air by the heater elements  54  and the subsequent expansion of the heated air into the heated space  30 . 
         [0031]    The redirection of the heated air from the space  46  below the tray  44  back into the heated space  30  as described above is achieved by the use of an angled lip  78  provided upon the upper edge of the upper portion of the front wall  26   b . The lip  78  extends across the upper portion of the front wall  26   b  between the side walls  20 . The lip  78  is angled inwardly with respect to the heated space  30 . The inclination of the lip  78  is chosen such that air is neither directly expelled from the cabinet  10  nor deflected out of the cabinet  10  by the lower shelves  38 , situations which can occur if the lip angle is either too shallow or too steep. In the embodiment shown the lip  78  is inclined to the vertical at an angle of around 15 degrees. The cabinet  10  utilises the natural ability of the heated air to rise in order to promote the circulation of heated air around and through the shelves  38  and around food products supported thereon. 
         [0032]    Circulation of heated air within the chamber  10  is also assisted by the configuration of the shelves  38 . Each shelf  38  is provided at its forward edge with a ticket strip  80  upon which product pricing and labelling information can be attached. The ticket strip  80  is further configured to act in the manner of a spoiler or similar aerodynamic aid which directs heated air which impinges upon it. The heated air is directed upwardly and towards the rear of the heated space as indicated by arrows  82 . For optimum efficiency the strip  80  is inclined at a predetermined angle to the upper surface  84  of the product support member  42 . In the embodiment shown the ticket strip  80  is inclined at an angle of 35 degrees. 
         [0033]    The shelves  38  may be configured such that the product support member  42  can be set and maintained at one of a range of inclination angles. For example the product support member  42  may be set at one of three positions corresponding to a flat position, where the shelf is substantially parallel to a reference plane such as the surface upon which the cabinet  10  is provided, and two inclined positions which are inclined with regard to the reference plane. For example, the support member  42  may be inclined at angles of 10 and 20 degrees to the reference plane. The ticket strip  80  is arranged on each shelf  38  such that the required inclination angle thereof relative to the upper surface  84  of the support member  42  is maintained irrespective of the inclination angle of the support member  42  relative to the reference plane. 
         [0034]    Referring now to  FIGS. 5 ,  6  and  7 , the construction of a shelf  38  is shown in greater detail. Each bracket  40  is substantially triangular and is provided with upper and lower attachment formations  102 , 104  which enable the bracket  40  to be fitted to appropriately configured mounting sites if the cabinet  10 . The upper attachment formation  102  is in the form of a hook  106  which is received in a slot of the cabinet  10 . The hook  106  includes a recess  108  into which an edge of the slot is received, in use. The lower attachment formation  104  takes the form of curved projection  110  having a plurality of spaced recesses  112 . The projection  110  is received in a slot of the cabinet  10 . In a similar manner to the hook  106 , an edge of the lower mounting member receiving slot is received in one of the recesses  112  of the projection  110 . It will be understood that the inclination angle of the bracket  40 , and hence the support member  42  is dependent upon which of the projection recesses  112  receives the edge of the slot. 
         [0035]    The product support member  42  comprises a frame  114  having portions of wire mesh  116  attached thereto. The edges of the frame  114  are folded and the brackets  40  are provided with formations  118  arranged to receive the folded edges. The ticket strip  80  comprises a substantially rigid portion  120  and a flexible portion  122 . The rigid portion  120  comprises a leg  124  which is attachable to the product support member  42  and a support strip  126  for the flexible portion  122  which is inclined relative to the leg  124 . The support strip  126  comprises an extension  128  of the leg  124  with a further strip  130  of material attached thereto. The flexible portion  122  is formed form an extruded strip of plastics material and includes an attachment recess  132  and a ticket receiving recess  134 . The attachment recess  132  is defined by a central wall  136  of the flexible portion which is provided on opposing edges with lips  138 . The ticket receiving recess  134  is defined between a the central wall  136  and a flap  140  connected thereto by a living hinge  142 . In use, the living hinge  142  is provided along the top edge of the ticket strip  80  so as to prevent the ingress of grease, oil or other matter into the ticket receiving recess  134 . The flexible portion  122  is removable from the rigid portion  120  for cleaning purposes or in instances where the flexible portion  122  needs to be replaced or renewed. 
         [0036]    A control panel  86  for the cabinet  10  is provided in the enclosed space  28  of the base portion  12 . The control panel  86  is arranged to permit an operator set the operating parameters of the cabinet. More specifically the control panel  86  permits an operator of the cabinet  10  to set the temperature at which the heated space  30  is maintained. 
         [0037]    The control panel  86  is provided with a fan motor cut-off timer which allows the fans  52  to continue to run for a predetermined time period once the heater elements  54  have been switched off, for example when the cabinet  10  is switched off at the end of the day. The overrunning of the fans  52  increases the service life of the fans  52  by reducing latent heat build up. The overrunning of the fans  52  also leads to a quicker cooling of the heated space  30  after shut down of the cabinet  10  which in turn permits daily cleaning of the cabinet to be carried out more quickly. 
         [0038]    The control panel  86  is further provided with an over temperature safety cut-out system which is arranged to detect abnormal rises in temperature of the cabinet  10 . If such a temperature rise is detected than the system cuts all power to the cabinet  10 . Abnormal temperature rises may be caused by, for example, failure of one or both fans  52  or an malfunction of the heater elements  54 . 
         [0039]    The control panel  86  is provided with an electronic temperature controller to regulate the temperature within the heated space  30 . The temperature within the heated space  30  is sensed by a thermocouple which is located in the downwardly directed heated air flow path at the rear of the cabinet  10 . The thermocouple is provided with appropriate shielding so as not to be effected by external factors which may adversely affect the operation of the thermocouple and hence cause it to give a false reading of the temperature of the heated space  30 . Such external factors may include, for example, draughts of cold air. 
         [0040]    It will be understood that the cabinet  10  is not intended to heat food products from cold, but instead is intended to retard the cooling of heated food products which are placed in the heated space  30 . Upon initial start up the cabinet  10  is operated to bring the heated space  30  up to the required temperature before heated food products are place therein. 
         [0041]    As indicated above, the speed of each fan  52  may be set and adjusted independently of the other via a dedicated voltage potentiometer  53  (one of which is shown in  FIG. 1 ). This feature permits the characteristics of the air curtain to be altered. During initial installation and commissioning of the cabinet  10  it may be observed that the cabinet  10  is subject to an incident external airflow such as, for example, a draught, which may cause deflection of air curtain. The speeds of the fans  52  can be set such that the air curtain is able to resist the influence of the draught. 
         [0042]    While the cabinet  10  described above is provided with a substantially uniform and uninterrupted rear wall  18 , an alternative embodiment of the cabinet  10  may be provided with a rear wall  18  having an access aperture such as a sliding door. The provision of a door of this type enables the cabinet to be replenished from the rear. It will further be appreciated that arrangements other than shelves  38  may be provided in the heated space  30 . For example adjacent brackets  40  may be provided with one or more rods which extend across the heated space  30  and from which food products may be suspended, hi an alternative embodiment the brackets  40  may be removed and replaced with a plurality of prongs which extend from the rear of the heated space  30  towards the open front  32  of the cabinet  10 . The prongs may be utilised to suspend food products in bags. 
         [0043]    The present invention seeks to retard the cooling of heated food products placed within the heated space  30 . The retarded cooling effect is realised by surrounding the food products with a controlled heated air environment and by preventing the food products from being subjected to draughts and the like. It will be appreciated that the cabinet of the present invention does not seek to heat the food products by surface conduction or radiation. The shelves or other product support means, as well as the walls of the cabinet, are not heated by conduction and/or radiation and hence are not heated to a temperature which may potentially be harmful to person retrieving a product from the heated space. It will further be appreciated that the presence of the air curtain across the open front of the cabinet prevents the escape of heated air from within the heated space. 
         [0044]    Exemplary embodiments have been disclosed above and illustrated in the accompanying drawings. It will be understood by those skilled in the art that various changes, omissions and additions may be made to that which is specifically disclosed herein without departing from the spirit and scope of the present invention.