Patent Abstract:
A container having a pair of side walls and end walls and corner walls being provided between a respective end wall and side wall, a flange formed on one of the corner walls, said flange functioning as a hinge, a ring member formed integrally with the flange, the ring being sized to sit on top of the container.

Full Description:
FIELD OF THE INVENTION 
       [0001]    The technical field relates generally to container and lid assemblies, for instance container and lid assemblies that can be used in the commercial food processing industry. 
       BACKGROUND OF THE INVENTION 
       [0002]    Various kinds of containers have been suggested over the years. Many containers designed for holding food include a main bottom section forming a tray, a dish, a bowl, a receptacle or the like, and each container is hermetically sealed around or near its top edges by a wrapping and/or a lid to protect the contents during the transportation, storage and handling. Some containers are sold to customers without any contents therein but others are sold together with food items, for instance as prepackaged meals or the like. 
         [0003]    Designing food containers for the commercial food processing industry can be challenging. For instance, since most of these containers are only designed to hold food items until eaten by the customers, it is desirable that the quantity of materials required for making them and the manufacturing costs be minimized. Unfortunately, this is not always easy to achieve since the containers and their lids must also meet other requirements, such as resisting shipping, storage and handling, including handling at the stores or the restaurants where they are sold. The containers must remain intact and constantly sealed, between the packaging process and the moment customers open them, to avoid contamination and spoilage. On the other hand, adding too many packaging layers or features, such as a protective box made of cardboard or the like, or additional layers of wrapping, to mention just a few, increases the volume of waste material to be recycled and/or discarded after their use. This situation is not desirable and it will likely dissatisfy many actual or potential customers. 
         [0004]    Further difficulties and challenges in the design of food containers are created when these food containers must also be used for heating/cooking food items directly therein, for instance in a microwave oven. In a microwave oven, the heat generated inside the food items is transferred to the container itself and the temperature of the container can eventually become very high. Containers must still remain sufficiently rigid even when heated at high temperatures. 
         [0005]    Even more challenging is the design of food containers used for heating/cooking food items directly therein and that can be reclosed after the initial opening by the customer. These food containers are used with lids that can be reclosed during heating/cooking and/or afterwards for transportation and storage. For example, some prepackaged meals require separate ingredients to be mixed and/or added before heating/cooling them, such as a meal where water must be added before heating/cooking. Some meals can also be packaged with ingredients that must be mixed together by the customer inside the container but where not all ingredients are mixed at the same time. An example is a stir-fry meal where a sauce or the like is added only after some cooking/heating time. Still, physical interventions by the customer during the heating/cooking process, for instance to stir the content, may be another reason to have a reclosable lid. Other situations exist as well. 
         [0006]    Containers must perform well in the hands of customers but they must also be easy to handle at the packaging end, for instance, by the packaging equipment. Some designs can be adequate for transportation, storage and handling but far less for the packaging process. Difficulties in handling containers and sealing their lids can increase costs and complexity of the packaging equipment and/or decrease the production rate. 
         [0007]    Still, some container designs can create difficulties for the customers when they attempt to remove the sealed lid. Containers with rectilinear sides and relatively sharp corners are often difficult to handle when the lids are very light and flexible. 
         [0008]    Unfortunately, none of the previously-suggested containers has proven entirely satisfactory to address many of the challenges encountered in the design of containers, particularly in the design of containers intended for the commercial food processing industry. 
         [0009]    It is therefore clear that improvements in the related technical field are still and will always be needed. 
       SUMMARY OF THE INVENTION 
       [0010]    According to one aspect of the present invention, there is provided a container, the container having a pair of side walls and a pair of end walls, corner walls extending between end walls and side walls, a flange formed on one of the corner walls, a ring member formed integrally with the flange, the ring being sized to sit on top of the container. 
         [0011]    According to a further aspect of the present invention, there is provided a container having at least one flange portion extending outwardly from a wall of the container, the flange having a proximal section adjacent the wall, the proximal section having a recess formed therein, a distal section remote from the wall, the distal section having an upwardly extending projection; and the upwardly extending projection being sized to fit within the recess. 
         [0012]    The container and lid of the present invention may be utilized in many different applications. In particular, in several of the embodiments, the containers are particularly suitable for the food industry and in particular, for packaging ready to use foods. 
         [0013]    The present embodiments of the present invention utilize containers which normally have a generally overall rectangular configuration. It will be understood, of course, that many different configurations can be utilized including those having various arcuate configurations. 
         [0014]    The containers are formed of conventional plastic materials and the containers are normally formed using a thermoforming process. However, other known processes may be utilized. 
         [0015]    The ring member of the present invention, in one embodiment, is formed as a portion of the container during a thermal forming process. The ring member is hingedly connected to the container and suitable retaining means may be utilized for securing the lid member to the top of the container. 
         [0016]    In a further embodiment of the present invention, the ring member is formed as part of the container and is then separated from the container to become a separate ring member. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    Having thus generally described the invention, reference will be made to the accompanying drawings illustrating embodiments thereof. 
           [0018]      FIG. 1  is an exploded isometric view of an example of a container and lid assembly based on the proposed concept; 
           [0019]      FIG. 2  is an isometric view of the container and lid assembly in  FIG. 1 , where the assembly is illustrated in a closed position; 
           [0020]      FIG. 3  is a top plan view of the container and lid assembly shown in  FIG. 2 ; 
           [0021]      FIG. 4  is a view similar to  FIG. 2  but where the assembly is illustrated in an opened position as the lid is unconnected to the container; 
           [0022]      FIG. 5  is an enlarged isometric view of the area inside line  5 - 5  in  FIG. 4 ; 
           [0023]      FIG. 6  is a transversal cross section view taken along line  6 - 6  in  FIG. 2 ; 
           [0024]      FIG. 7  is an enlarged view of the area inside line  7 - 7  in  FIG. 6 ; 
           [0025]      FIG. 8  is a semi-schematic view of an example of a mold in which the container and the lid frame are molded together; 
           [0026]      FIG. 9  is a cross-sectional view of a variation of a lid frame; 
           [0027]      FIG. 10  is a top plan view of a bowl and flange when thermoformed; 
           [0028]      FIG. 11  is top plan view of the bowl and ring after the exterior edges are folded; 
           [0029]      FIG. 12  is a partial sectional view illustrating a flange arrangement for a recess and a protrusion; 
           [0030]      FIG. 13  illustrates folding of an outer part of a flange to mate with an inner portion of the flange, 
           [0031]      FIG. 14  is a top plan view of a further embodiment of the container according to the present invention; and 
           [0032]      FIGS. 15 and 16  illustrate folding of the member of  FIG. 14  to mate with the top of the container. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0033]      FIG. 1  is an exploded isometric view of an example of a container and lid assembly  100  based on the proposed concept. The assembly  100  is used for packaging a product, for instance one or more food items. Although the proposed concept is especially well adapted for holding meals and other food items, it is possible to design and/or use the assembly  100  for holding one or more products that are unrelated to the food industry. The following detailed description refers to the context of the commercial food processing industry only for the sake of simplicity. 
         [0034]    As suggested by its name, the assembly  100  includes a container  102  and a corresponding lid  104 . The container  102  includes a main body  110  having one or more walls defining a hollow interior compartment  112  for storing the food items to be packed therein. The container  102  has an opening  114  at the top that is defined by the inner edge of an outwardly-projecting container rim  120 . The container rim  120  is made integral with the main body  110 . The top of the container rim  120  is at the horizontal in normal use. The opening  114  is substantially rectangular in shape, with rounded corners and slightly curved sides between the corners. Variants are possible as well. For instance, the container  102  could have an opening with substantially straight sides and sharper corners, an opening with a nonrectangular shape, such as a rounded shape, a triangular shape or a shape with more than four sides, etc. Many other variants are possible as well. 
         [0035]    In the illustrated example, the main body  110  includes a bottom wall and four upwardly-disposed side walls configured to form a bowl or the like. The wall or walls forming the main body  110  are airtight and liquid tight. 
         [0036]    It should be noted that the shape of the main body  110  of the illustrated container  102  is only one example of implementation. Variants are possible. 
         [0037]    The container  102  can be made using a thermoforming process or an injection molding process, for instance using a plastic material. Other materials and/or manufacturing processes can be used as well. The wall or walls forming the main body  110  of the container  102  can be relatively thin and the container rim  120  will stiffen the container  102 , even if the container rim  120  is also relatively thin to minimize the quantity of material. 
         [0038]    The lid  104  includes a ring-shaped lid frame  130  and a membrane  132  that will be attached over the lid frame  130  at some point of the packaging and/or manufacturing process. The lid frame  130  includes a relatively flat strip portion  134  having a continuous flat top surface and a continuous flat bottom surface. The periphery of the membrane  132  will adhere to the top surface of the lid frame  130  to form an airtight and liquid tight seal. The lid  104  is thus made with a minimized quantity of material and will be very light. 
         [0039]    The lid frame  130  can be made using an injection molding process, for instance using a plastic material. Other materials and/or manufacturing processes can be used as well. However, the lid frame  130  is not molded directly to or over the container rim  120 . The lid frame  130  is only put in position onto the container rim  120  after the molding process. 
         [0040]    The membrane  132  is in the form of a thin film, for instance a plastic film or a foil. Other materials can be used as well, depending on the actual implementation. The membrane  132  can be transparent, translucent or opaque, depending on the needs. 
         [0041]    The lid frame  130  of the illustrated example also includes two diametrically opposite corner latching tabs  136 ,  138  that are each made integral with the outer side edge of the lid frame  130 . Each latching tab  136 ,  138  has a proximal section that extends outwards from the side edge of the flat strip portion  134  and a distal section that extends downwards. The latching tabs  136 ,  138  are designed to prevent them from interfering with the continuity of the contact of the bottom surface of the flat strip portion  134  with the outer peripheral top surface  122  when it rests thereon. The lid frame  130  of the illustrated example also includes a lift tab  140  that is made integral with the free end of the distal section of the first corner latching tab  136 . Only one lift tab is provided in the illustrated example. The lift tab  140  extends horizontally outwards from the distal portion of the first corner latching tab  136 . Variants arc possible as well. 
         [0042]    As can be seen, the lid  104  is devoid of a peripheral skirt or the like. The size of the latching tabs  136 ,  138  is also kept to a minimum. Overall, this will greatly facilitate the opening and closing of the lid  104 . A lesser force is required to handle it and as a result, it is less likely to undergo a plastic deformation because the customer exerted an excessive pulling force. The lid frame  130  is relatively small and can be prone to deformation when subjected to an excessive pulling force. 
         [0043]      FIG. 2  is an isometric view of the container and lid assembly  100  in  FIG. 1 , where the assembly  100  is illustrated in a closed position. The lid  104  is then attached to the container  102 , more specifically to the container rim  120 . In  FIG. 2 , the membrane  132  is sealingly attached to the lid frame  130 . 
         [0044]      FIG. 3  is a top plan view of the container and lid assembly  100  shown in  FIG. 2 . 
         [0045]      FIG. 4  is a view similar to  FIG. 2  but where the assembly  100  is illustrated in an opened position. The lid  104  is then unconnected to the container  102 . 
         [0046]    As can be seen, for instance in  FIGS. 3 and 4 , the top side of the container rim  120  includes an outer peripheral top surface  122  and an inner peripheral top surface  124 . Each of these surfaces  122 ,  124  are flat and continuous. They are also substantially horizontal in normal use. However, the outer peripheral top surface  122  is slightly vertically below the inner peripheral top surface  124  so as to receive the bottom surface of the lid frame  130  when the lid  104  is in a closed position. These mating surfaces are configured and disposed to form an uninterrupted seal around the entire perimeter of the container rim  120 . 
         [0047]      FIG. 5  is an enlarged isometric view of the area inside line  5 - 5  in  FIG. 4 . As can be seen, the outer peripheral top surface  122  includes a through hole  150  at the corner where the first latching tab  136  is located when the lid  104  is in a closed position. A similar hole  150  is also provided at the opposite corner, thus at the corner where the second latching tab  138  is located. In the illustrated example, these holes  150  have an oblong shape that is generally oriented parallel to the medial axis of the outer peripheral top surface  122 . Variants are possible as well. For instance, the holes  150  can be provided with other shapes, including for instance a “lens” shape to help in aligning the studs  152  at the center of the holes  150 . 
         [0048]      FIG. 5  also shows that the container rim  120  of the illustrated assembly  100  includes a downwardly projecting skirt  126  extending around the entire periphery of the container  102 . The skirt  126  promotes rigidity. Variants are possible as well. 
         [0049]      FIG. 6  is a transversal cross section view taken along line  6 - 6  in  FIG. 2 . It thus shows the lid  104  in a closed position.  FIG. 7  is an enlarged view of the area inside line  7 - 7  in  FIG. 6 . As can be seen, these figures show one of the studs  152  provided to engage the inner edge of a corresponding hole  150 , as best shown in  FIG. 7 . A similar stud  152  is provided at the opposite corner to engage the other hole  150 . These studs  152  have a substantially circular cross section in the illustrated example. The engagement of the studs  152  with their corresponding holes  150  can be an interfering engagement, including for instance using a notch (not shown) or the like to create a snap fit interlocking connection. This removable interfering engagement will create a retention force resisting the lifting of the lid  104  and interlocking the lid  104  with the container  102 . However, the interfering engagement can be removed upon lifting the lid frame  130  using a mild force. Using the studs  152  and the corresponding holes  150  also greatly facilitates the closing of the lid  104  since the lid frame  130  is made of a relatively flexible part. It can become very flexible at high temperatures and the studs  152  can facilitate the positioning. The customer can used their thumbs to urge the studs  152  into the holes  150  when closing the lid  104 . Variants are possible as well. 
         [0050]    The latching tabs  136 ,  138  also help in centering the lid  104  on the container  102  and they can be shaped to engage, with a mild interfering force, the bottom edge of the skirt  126 . Each latching tab  136 ,  138  can be provided with an undercut (not shown) or a similar feature to create an interlocking connection with the bottom edge of the skirt  126 . They can even replace the studs  152  and their holes  150  in some implementations. Variants are possible as well. 
         [0051]    The holes  150  have an oblong shape in the illustrated example. This feature is to facilitate the positioning by the customer. Variants are possible as well. 
         [0052]      FIG. 7  also shows that the top surface of the lid frame  130  and the inner peripheral top surface  124  of the container rim  120  are substantially flush with one another when the lid  104  is in a closed position. The bottom surface of the membrane  132  is then directly above the inner peripheral top surface  124 . 
         [0053]    Still,  FIG. 7  shows that the inner side edge of the flat strip portion  134  is spaced apart from the outer edge bordering the inner peripheral top surface  124 . This space can provide more room for aligning the parts when they are hot. The space also provides an increase of the manufacturing tolerances, thus mitigating the risks of having parts being rejected because they are too wide after the molding process. 
         [0054]    During the packaging process, the item or items can be put inside the hollow interior compartment of each container  102  with the lid frame  130  being already in an interlocking engagement with the container rim  120 . This previous step can be achieved by hand or by appropriate equipment. The containers  102 , with their lids  104  thereon, can still be stacked so as to minimize space. Variants as possible as well. 
         [0055]    An interesting benefit of the proposed concept is that since no peripheral skirt is provided on the lid  104 , the handling of the container  102  with the pre-connected lid frame  130  during the packaging process is made easier since a stack of these parts can be supported anywhere underneath the container rim  120 , with the exception of the two corners with the latching tabs  136 ,  138  are provided, without the risks of accidentally lifting a portion of the lid frame  130  from the container rim  120 . 
         [0056]    The membrane  132  is added at the end of the packaging process to simultaneously form the lid  104  and to seal the whole assembly  100 . For instance, if the membrane  132  is made of a thermoplastic material, the membrane  132  can be heated and pressure can be applied so as to simultaneously bond the outer perimeter of the membrane  132  to the outer and inner peripheral top surfaces  122 ,  124 . This can be done in a single operation during which the underside of the container rim  120  is supported by a die while the membrane  132  is urged onto the lid frame  130  and onto the exposed inner peripheral top surface  124  by a heated pressure plate. The combination of heat and pressure bonds the membrane  132  over the top surface of the lid frame  130  and over the inner peripheral top surface  124 . 
         [0057]    If desired, the inner peripheral top surface  124  can be positioned slightly lower than the top surface of the flat strip portion  134  when the lid  104  is in a closed position. This will make the bond between the inner peripheral top surface  124  and the membrane  132  slightly weaker than the bond between the top surface of the flat strip portion  134  and the membrane  132 . Still, as shown in  FIG. 7 , the width of the outer section of the membrane  132  that is fused onto the top surface of the flat strip portion  134  is larger than the width of the adjacent inner section of the membrane  132  that is fused onto the inner peripheral top surface  124 . These features will make the membrane  132  less prone to detach from the lid frame  130  during the initial unsealing of the assembly  100  by the customer and will also decrease the required pulling force. This decrease of the pulling force can mitigate the risks of accidentally tearing the membrane  132  when the assembly  100  is unsealed. Variants are possible as well. 
         [0058]    In use, to open the sealed assembly  100 , the customer will move the lift tab  140  upwards to create a peeling force that will progressively detach the membrane  132  from the inner peripheral top surface  124  of the container rim  120 , starting at the corner adjacent to the lifting tab  140 . The membrane  132  will stay attached on the lid frame  130  since the peeling motion will only remove the membrane  132  from the inner peripheral top surface  124 . Thus, it is relatively easy for the customer to lift a corner of the lid  104  using the lift tab  104  and then lift the whole lid  104  to access the interior of the container  102 . This way, the customer can add liquids or other ingredients, for instance additional ingredients from a pouch or the like. The lid  104  can be reclosed before continuing the heating/cooking process. 
         [0059]      FIG. 8  is a semi-schematic view of a mold  200  in which the container  102  and the lid frame  130  are molded together in a same injection shot of molten plastic material but in separate cavities. The mold  200  includes a first cavity  202  for the container  102  and a second cavity  204  for the lid frame  130 . Both cavities  202 ,  204  are in fluid communication using an intervening channel  206 . The channel  206  will also be filled with the molten plastic material after the injection shot and as the plastic material solidifies, it will form a connector linking the outer edge of the container rim  120  to the outer edge of the lid frame  130 . This connector  206  can be removed or cut to completely separate the container  102  and the lid frame  130 . However, one can also keep the connector  206  to facilitate handling during the packaging and/or by the customer, provided that the connector  206  remains relatively flexible at room temperature and is located at the corner opposite the corner with the lift tab  140 . The connector  206  can be useful for keeping the orientation of the lid frame  130  with reference to the container  102  and for preventing a customer from attempting to close the lid  104  while the studs  152  are at the corners where no holes are present. 
         [0060]      FIG. 9  illustrates an alternative embodiment in which an injection molded snap ring  208  is placed on top of a flange  210  to a thermoformed bowl. The flange  210  is welded to the thermoformed bowl. The ring can also be welded directly to the container so that when one opens the lid, the film will stick to the ring, but the ring will be detached from the container. The ring will also snap in the flange. Preferably, the flange and ring are injected molded. 
         [0061]    Alternative embodiments are illustrated in  FIGS. 10 to 14 . 
         [0062]    Referring to the embodiment of  FIGS. 10 and 11 , there is illustrated a bowl or container  312 , includes a base  314 . Extending upwardly from base  314  are pair of side walls  316  and a pair of end walls  318 . At the point of joinder of and end wall  318  with a side wall  316 , there is provided bend lines  320  which form corner walls  322 . Each corner wall is located near a respective side wall  316  and end wall  318 . 
         [0063]    Extending outwardly from side walls  316 , end walls  318  and corner walls  322  there is a flange which has an inner or proximal flange portion  324  and an outer or distal flange portion  326 . Between distal portion  326  and proximal portion  324 , there is a crease or fold line  328  to permit distal portion  326  to fold over on top of proximal portion  324 . Inner or proximal portion  324  is provided with recesses  330  while distal or outer portions  326  are provided with a protrusion  332 . Protrusions  332  are designed to mate with recesses  330  and lock the two pieces together. 
         [0064]    As has previously been described, container  312  is provided with a upwardly extending top surface  323 . Top surface  323  extends above proximal flange portion  324  and distal flange portion  326 . This arrangement permits the membrane layer (not illustrated) secured to the flange portions to seal against upper surface  323 . 
         [0065]    In the embodiment of  FIGS. 12 and 13 , there is illustrated a portion of a bowl or a container which has a base  364  and a side wall  366  extending therefrom. The illustration includes a inner or proximal flange portion  368  and an outer or distal flange portion  370 . Proximal flange portion  368  includes recesses  372  while distal flange portion  370  includes a protrusion  374  designed to mate with recess  372 . This is done by folding of the distal flange  372  over top of proximal flange portion  368 . 
         [0066]    A further embodiment is illustrated in  FIGS. 14 to 16 . In this embodiment, there is provided a bowl or container  338  which has a base or bottom  340 . Extending upwardly from base  340  are a pair of side walls  332  and a pair of end walls  344 . Creases  346  are provided to form corner walls  348 . The top of the container includes an upper wall  350 . 
         [0067]    At one of the corner walls  348  there is provided a hinge  352  which is connected to ring member  356 . Ring member  356  has protrusions which are designed to seat in recesses  354  of a flange  360 . As has been previously described in the embodiments, there is also an upper wall  350  which is of a height to seat the above flange  360 . A flexible membrane (not shown) is also utilized. 
         [0068]    It will be understood that the above described embodiments are for purposes of illustration only and that changes and modifications may be made thereto without departing from the spirit and scope of the invention.

Technology Classification (CPC): 1