Abstract:
This invention relates to the field of receptacles for the carriage and cooking of food. More particularly, this invention refers to an unfoldable laminar tub for the packaging, cooking and delivery of popcorn, which being capable of being spread and assembled is useful for the packaging and carriage of corn kernels as well as for its cooking and delivery.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates to the field of receptacles for the carriage and cooking of food. 
         [0002]    More particularly, this invention refers to an unfoldable laminar tub for the packaging, cooking and delivery of popcorn, which being capable of being spread and assembled is useful for the packaging and carriage of corn kernels as well as for its cooking and delivery. 
       PRIOR ART 
       [0003]    Different types of packages or packings used for the delivery and cooking of corn kernels are known up to date. 
         [0004]    For instance, tubs or boxes are known which are provided in an assembled way and, as a consequence, they have certain disadvantages for their carriage and storage as well as for their position in supermarket gondolas and handling by consumers. Likewise, most of these tubs or boxes are especially designed according to their content, that is to say popcorn mixed with fat matter. Therefore, their constitution is conditioned by the type of special laminar or multi-layer materials to be used. 
         [0005]    Likewise, flexible bags are known which are provided in a folded way and tightly closed. In comparison with tubs, said bags are subject to bigger inconveniences such as, for example, breakages or cuts in their laminar walls with a subsequent loss since the bag must be disposed. For this kind of problems, bags comprised of high strength and/or multi-layer laminar materials are used. However, said materials enhance their strength and functionality but increase costs considerably. 
       ADVANTAGES AND PURPOSES 
       [0006]    An advantage of this tub is that while being a packaging means for corn kernels without fat matter, it may be easily converted, in a first instance, into a cooking chamber for corn kernels and then, after the popcorn had been obtained, into a delivery container for their consumption. 
         [0007]    Another advantage is that it may be used for corn kernels prepared to be cooked without fat matter. Its very simple and functional constitution makes it possible to be structured in a cellulosic laminar material without the addition of special laminar layers or a multi-layer laminar material. 
         [0008]    From a production point of view, this invention relates to a tub which is very easy to fill with kernels and it also has the advantage of having a low unit cost. 
         [0009]    Another advantage is that, when it is disassembled, this tub is extremely flat, which simplifies its transportation and storage as well as its use by the user. Its expansion or widening is only made at the cooking time so that the cooking chamber in which the kernels shall burst until becoming popcorn be formed. 
         [0010]    Even when constituted by a cellulosic laminar material, such as cardboard or thin cardboard, its expansion ability and its closure create conditions so that, under its exposure to microwaves, an appropriate increase of the inner temperature is produced within the cooking chamber, which has a favorable effect on a quick and efficient kernel cooking and burst process. 
         [0011]    The particular constitution of the tub makes its handling by the consumer quick and simple. It also enables the easy conversion of the cooking receptacle into a delivery container from which the consumer may easily help himself. 
     
    
     
       ILLUSTRATION 
         [0012]    For a better clarity and understanding reasons of the object of the invention, it is illustrated by means of several figures in which it has been represented in one of its preferred embodiments as an example and not limitative way: 
           [0013]      FIG. 1  is an elevational top view of the die-pressed laminar sheet that integrates this unfoldable laminar tub. 
           [0014]      FIG. 2  is an elevational rear side view of this assembled tub—without widening spreading—and with closed laminar edges, thus serving as a package for the kernels contained within the receptacle. 
           [0015]      FIG. 3  is an elevational front side view of this assembled tub—without widening spreading—with closed laminar edges. 
           [0016]      FIG. 4  is an upright cross-section view according to a section appearing indicated in  FIG. 3  which enables to see the receptacle closed with the corn kernels inside it. 
           [0017]      FIG. 5  is an elevational front side view of this assembled tub after the widening spreading has been made. 
           [0018]      FIG. 6  is an upright cross-section view according to a section appearing indicated in  FIG. 5 , which enables to see the receptacle already converted into a cooking chamber. In its inner side, the popcorn may be seen. The opening of the head portions converts the receptacle into a delivery container. 
           [0019]      FIG. 7  is a top perspective view of this assembled tub after the widening spreading has been made. 
       
    
    
       [0020]    In the different figures, the same reference numbers indicate like or corresponding parts and the set of several elements have been indicated with letters. 
       LIST OF MAIN REFERENCES 
       [0000]    
       
         
           
             ( 1 ) Laminar sheet. 
             ( 1   a ) Front part of the laminar sheet ( 1 ). 
             ( 1   b ) Rear part of the laminar sheet ( 1 ). 
             ( 2 ) Base portion. 
             ( 2   a ) Central fold line of the base portion ( 2 ). 
             ( 2   b ) Base folding lines of the base portion ( 2 ) [They are proximally located at both sides of the central folding line ( 2   a )] 
             ( 3 ) Side walls. 
             ( 4 ) Head portions. 
             ( 4   a ) Head folding lines 
             ( 5 ) Detachable laminar edges 
             ( 5   a ) Detachment cutting line 
             ( 6 ) Linking flanges. 
             ( 6   a ) Bottom ends of the linking flanges ( 6 ). 
             ( 7 ) Supporting side portions. 
             ( 7   a ) Side folding line. 
             ( 7   b ) Supporting folding lines. 
             ( 8 ) Packaging closed receptacle. 
             ( 8   a ) Cooking chamber and delivery container 
             ( 20 ) Corn kernels. 
             ( 20   a ) Popcorn. 
           
         
       
     
       DESCRIPTION 
       [0041]    Generally speaking, this invention refers to an unfoldable laminar tub for the packaging, cooking and delivery of popcorn comprising a closed receptacle ( 8 ) which contains corn kernels ( 20 ) without fat matter and a transversally unfoldable base portion ( 2 ) which determines the widening until forming a cooking chamber ( 8   a ) for microwaves. This cooking chamber ( 8   a ) is closed by means of head portions ( 4 ) which, after the cooking, may be opened to convert the cooking chamber ( 8   a ) into a delivery container of popcorn ( 20   a ). 
       DETAILED DESCRIPTION 
       [0042]    More particularly, this tub is formed from a die-pressed laminar sheet ( 1 ) in which a front part ( 1   a ) and a rear part ( 1   b ). 
         [0043]    In this embodiment, both parts ( 1   a )( 1   b ) are joined at the level of a central folding line ( 2   a ) delimiting them. In other embodiments, both parts ( 1   a )( 1   b ) may be delimited by a side fold line which is common to their two side walls ( 3 ). 
         [0044]    The tub is shaped by placing the front part ( 1   a ) opposite the rear part ( 1   b ) and the reciprocal joining—by means of sticking or any other suitable technique for said effect—between the detachable laminar edges ( 5 ) and the joining between the linking flanges ( 6 ) and the side walls ( 3 ). In these conditions, between both side walls ( 3 ) the closed packaging receptacle ( 8 ) remains formed within which there are corn kernels ( 20 ) prepared to be cooked without fat matter. 
         [0045]    On the top of the tub, the detachable laminar edges ( 5 ) are extensions of the side walls ( 3 ), which are delimited by respective cutting or weakness lines ( 5   a ) that enable the cut to separate them. 
         [0046]    The detachment of the detachable laminar edges ( 5 ) releases the access to the receptacle ( 8 ) and enables the deformation of the tub for its widening. 
         [0047]    On the bottom part of the tub, there is a transversally unfoldable base portion ( 2 ). Within it, there is a central fold line ( 2   a ), and at both sides of said line there are two proximally located base folding lines ( 2   b ). For the transversal unfolding of the base portion ( 2 ), it is necessary to recess the central folding line ( 2   a ) inwards the receptacle ( 8 ), which is possible by folding said base folding lines ( 2   b ). 
         [0048]    On the top part of the tub, the transversal unfolding remains supported by the depression of the head portions ( 4 ) which remain superimposed thus closing said top part and forming the cooking chamber ( 8   a ). 
         [0049]    On the side part of the tub, there is a pair of side portions ( 7 ) which are transversally unfoldable until they are assembled as a transversal widening support. Each supporting side portion ( 7 ) comprises a side folding line ( 7   a ) which recession into the interior of the receptacle ( 8 ) is made possible by means of proximal supporting folding lines ( 7   b ). 
         [0050]    With regard to the folding lines ( 4   a )( 2   a )( 2   b )( 7   a )( 7   b ), some or all of them may be partially die-pressed in order to coadjuvate with their folding function. 
         [0051]    With regard to the constituting material, in view of the fact that this tub is particularly suitable for cooking corn kernels ( 20 ) prepared for its cooking without fat matter, it has been provided that it be comprised of a cellulosic laminar material. In this case, due to the absence of fat matter, it does not require especial or additional laminar layers. 
       Set Operation: 
       [0052]    The detachment of the detachable laminar edges ( 5 ) enables to deform the side walls ( 3 ) of the tub and depress the head portions ( 4 ) until they become superimposed thus closing the receptacle ( 8 ). 
         [0053]    On the bottom part of the tub, the depression of the central folding line ( 2   a ) and the fold of the base folding lines ( 2   b ) cause the raising of the base portion ( 2 ) and drive the side widening of the receptacle ( 8 ). 
         [0054]    The unfolding of the tub is completed in the side supporting portions ( 7 ) by means of the depression of the side folding lines ( 8   a ) and the folding of the supporting folding lines ( 7   b ). It takes places until said side portions ( 7 ) remain as widening transversal support of the receptacle ( 8 ), which in this way is converted into a cooking chamber ( 8   a ). 
         [0055]    Under these conditions, the tub may be subjected to the action of a microwave oven until the kernels ( 20 ) burst out and become popcorn ( 20   a ). 
         [0056]    After the cooking had been finished, the head portions ( 4 ) are opened and the cooking chamber ( 8   a ) is converted into a popcorn ( 20   a ) delivery container. For a better use, it has been provided that the linking flanges ( 6 ) finish in respective bottom ends ( 6   a ), which are the standing legs. 
         [0057]    There is no doubt that when this invention is put into practice, several modifications may be made as to certain building and shape details are concerned and it does not mean that they going beyond the main principles clearly stated in the following claims.