Patent Publication Number: US-2009236255-A1

Title: Stackable Independent Container System

Description:
The present invention refers to a system of stackable modular containers specifically but not exclusively intended for the conservation and transport of foodstuffs. 
     Plastic material food containers used for the conservation and transport of food of various types are known in the field of what are known as “household objects”. 
     For example, the necessity to put fresh and/or cooked food back into the refrigerator or freezer (or into another cold environment), for the purpose of conservation for use within relatively short periods of time, is well known. 
     Plastic material food containers are also used to transport the above-mentioned food from one place to another, for example on the occasion of transfers from house to house, trips, excursions and so forth. 
     To meet the above-mentioned requirements, other stackable containers have already been proposed, with or without positive sealed closure between one container and the next, positive sealing being preferred as it ensures a properly sealed closure, avoiding both the leaking of the contents and inadequate conservation with consequent loss of flavours and unwanted contamination of the refrigerator. 
     Furthermore, extraction and transport of the stack of stacked containers without a positive closure is not easy and safe, as clumsy handling may easily cause the sudden and unexpected separation of the stacked containers, with the resultant leaking of the contents. The stackable container systems provided with a positive closure known to date generally present the disadvantage of being made in such a way as to only provide for a top lid. The closing of a lower container therefore takes place through the base of the container above it. 
     As a result of this, not only is the parallel and independent use of multiple containers impossible, but also various different inconveniences arise during usage. For example, the base of a container used as the lid of a lower container, as well as the lid itself, are usually in contact with the material contained in such lower container. 
     In the case of use with food, the base of the container used as the lid or the lid may therefore become dirty and oily, and may no longer be used to cover another container without causing the contamination of the material contained in the latter. 
     Furthermore, the dirty base of a container may not be placed on a surface without making the surface dirty in its turn, making the handling of the stack of containers difficult. 
     Thus, for example, the system of modular containers described in European patent EP 1 026 090 comprises a plurality of equal and stackable containers, and only one top lid. 
     The containers of such a system are provided with a means of positive hooking between one container and the next in vertical alignment, so that an upper container may serve as the lid for a lower container. 
     The containers in such a system however present the disadvantage of not being able to be used separately as the system is made in such a way as to provide only one top lid. They also present the disadvantages of use described previously. 
     The general object of the present invention is to resolve the above-mentioned drawbacks of the known art in an extremely simple, economical and particularly functional manner. 
     A further object is to devise a stackable container system in which the individual containers are usable separately. 
     A further and final object is to devise a stackable container system which is particularly useful and practical to use. 
     In view of the above-mentioned objects, according to the present invention, a stackable container system has been designed, having the characteristics described in the appended claims. 
    
    
     
       The structural and functional characteristics of the present invention and its advantages in relation to the known art will be made clearer and more evident from a review of the following description, which refers to the appended drawings, which show a practical embodiment of the invention itself. In the drawings: 
         FIG. 1  shows a perspective view of the container system according to the invention in a first stacked use configuration; 
         FIG. 2  is an exploded view of the configuration of  FIG. 1 ; 
         FIG. 3  shows a perspective view of the container system according to the invention in a second stacked use configuration; 
         FIG. 4  is an exploded view of the configuration of  FIG. 2 ; 
         FIG. 5  is a top plan view of a lid used in the container system according to the invention. 
     
    
    
     When referring to the drawings, the stackable container system being discussed is indicated overall by  10  and comprises a plurality of containers  11  and at least one closing element or lid  12  adapted to the closing of the container  11  arranged on top of the stack  10 . 
     The containers  11  and lids  12  described in the exemplary, and not limiting, embodiment have a rectangular plan with rounded corners, but they may also have any other geometric form adapted to the object. The height of the containers may also be different. 
     The stackable container system  10  may also provide for more lids  12  shaped in such a way as to be interposed between one container  11  and the next in the stack  10 . As such, each lid  12  presents on its top a central depression  8  formed in a complementary manner in relation to the narrow bottom section  17  of the containers  11 , so as to house it. 
     The narrow bottom section  17  of the containers  11  ensures that these may also be stacked one onto the other, in any succession, as shown in  FIGS. 3 and 4 , by inserting (with light effort) the bottom section  17  of a container into the top of the container below. To this end, the external dimensions of the bottom section  17  and the internal dimensions at the top of each container are complementary, and therefore such as to ensure hooking with light effort between the surfaces in contact. 
     Similarly, the external dimensions at the top of each container  11  and the internal dimensions of the free ends  14  of the walls of each lid  12  are complementary and therefore are such as to ensure hooking with light effort between the surfaces in contact. As such, the lid  12  may advantageously present a widened-section, free terminal portion  14 . 
     According to the present invention, a positive hooking system is provided on the sides of each container  11  and of each lid  12  (transversal sides  15 , 16 ). Such a hooking system allows both the connection between a container  11  and another container above it and the connection between a container  11  and a lid  12 , to achieve the positive sealed closure of the container below. Furthermore, the same hooking system is usable for the connection of a lid  12  and a container  11  above, a connection necessary for the fast and safe hooking to the stack  10  of a container  11  closed by means of lid  12 . 
     More precisely, said hooking system is made up of winglets  18  which are hinged, for example by means of a line of lesser resistance, near the top edge of the container  11  or respectively at the perimeter of the top surface of the lid  12 . 
     Each winglet  18  presents, in the middle, an opening  20  suitable for being hooked to, as shown in  FIG. 1  and in  FIG. 3 , a projecting tooth  21 , in vertical alignment, from the container  11  above, near the bottom section  17 , or a projecting tooth  22 , in vertical alignment, from the lid  12  above. 
     In this way, it is clear how a plurality of stacked containers, such as, for example, that shown in  FIG. 1 , may be positively sealed by means of the respective lids  12  by simply hooking the opening  20  of a winglet  18  present on a lower container  11  to the tooth  22  of a lid  12  above, and successively stacked and hooked to each other by means of the hooking of the opening  20  of the winglet  18  present on a lid  12  below, to the tooth  21  of a container  11  above. 
     Similarly, it is clear how a plurality of stacked containers  11 , such as, for example, that shown in  FIG. 3 , may be positively sealed, one to the other, by simply hooking the opening  20  of a winglet  18  of a lower container  11  to the tooth  21  of an upper container  11 . The positive closing of a lid  12  onto a container  11  below takes place in a perfectly corresponding manner in this case as well. 
     The stacking operation is therefore implemented with the winglets  18  lowered or open in the position shown in  FIGS. 2 and 4 , after having put the contents back into the respective containers, while the positive closing of a container  11  by means of the lid  12  or by means of an upper container  11  is implemented by rotating the winglets  18  upwards and engaging, as mentioned above, the opening  20  with the tooth  22  or respectively  21 . The hooking between a lid  12  and a container above  11  takes place in a similar fashion. Lastly, the lid  12  presents on its top, at each winglet  18 , a recessed seat  13  in the centre of which a retaining tooth  23  is provided. Such seats  13  are substantially formed in a manner complementary to the winglets  18  in such a way as to house them, the retaining teeth  23  being arranged at the opening  20 , when the winglet  18  is housed in said seats  13 . 
     In the case of the top lid  12 , where the winglet  18  is not used to hook to an upper container  11 , it is therefore possible to house the winglet in the seat  13  by linking it to the retaining tooth  23  so that it does not project from the stack of containers  10 . 
     Lastly, a grip handle is made on each winglet  18 , through an arched configuration of the winglet itself, which leaves space for the insertion of the fingers of a hand in the intrados arch. 
     From what has been described above in reference to the figures, it has therefore been shown how the stackable container system according to the present invention is particularly useful and advantageous. 
     The object mentioned in the preamble of the description to make a system of modular, equal and stackable containers with a sealed closure has been achieved, in which the containers of the stack are positively interconnected by means of a chain closure system, in which, in order to be able to use the individual containers independently of the others, the lids may be interposed between one container and the next in the stack. 
     The system of the invention also offers the advantage of being able to increase the overall containment space of the containers, by simply using lids which also define a containment space. If such increase of the containment space could be previously exploited only for the top container, it is now possible to exploit it for one or more of any container in the stack with the system according to the invention. 
     In addition to this, a further advantage of the container system of the present invention may be appreciated in the case of using the containers for food, when one normally wishes to avoid the mutual contamination of the materials contained in the individual containers. The possibility of interposing lids ensures the interchangeability of the positions of the individual containers, the opening of the same and/or the removal of only one container from the stack, without the risk of contamination of the materials contained in them. 
     Of course, the embodiments of the stackable container system according to the invention may be different from that shown only by way of example and not limitation in the drawings, as may the materials. 
     For example, not necessarily all the containers must be closed by a lid, but at least one of them may be closed by the bottom of the container above. 
     The protection scope of the invention is therefore defined by the appended claims.