Patent Abstract:
A sealable multicompartment container comprises a first inner compartment surrounded by a second compartment in the form of an annular trough, both compartments having upper edges for sealing with a closure lid and being joined by a folded wall member pliable to permit unfolding, thereby extending the container depth and merging the two compartments.

Full Description:
The invention relates to sealable multicompartment containers and particularly to multicompartment food or drinks containers. 
     BACKGROUND OF THE INVENTION 
     Various products, including some food and drink products, are sold in packaged form with more than one component held in sealed isolated compartments prior to use and which are required to be mixed at the time of use. In the food and drink industry such products include various dairy products such as flavoured drinks or yoghurts. In other industries multiple chemical components may be held in sealed separate compartments up till use such as for example adhesive products where mixing is required prior to use. 
     It is an object of the present invention to provide an improved multicompartment container which may be formed with more than one compartment which may store constituents in isolation when the container is sealed but which may be adapted by change of shape after opening in order to provide a single container in which the constituents are mixed. 
     SUMMARY OF THE INVENTION 
     The invention provides a sealable multicompartment container having a first inner compartment surrounded by a second outer compartment each compartment having perimeter walls with upper edges of the walls of each compartment terminating in a closure plane with sealing regions on the upper edges for engaging with a closure lid to provide sealing of the container and isolation of each of the compartments, an outer perimeter wall of the first compartment and an inner perimeter wall of the outer compartment being formed by a folded wall member which is pliable to permit unfolding by pulling the inner compartment relative to the outer compartment, when the lid is removed, in a direction away from said upper edges so as to extend the container depth and cause the outer and inner compartments to merge into a single compartment. Preferably the second compartment forms an annular trough around the first compartment. 
     Preferably the first and second compartments have perimeter walls which are circular and concentric with each other at their upper edges. 
     Preferably the upper edges of the perimeter walls are formed with flat regions of sufficient area and rigidity to permit bonding in abutment with a sealable lid. 
     Preferably the inner and outer compartments are of similar depth when the container is not extended. 
     Preferably the inner perimeter wall of the outer compartment is formed of flexible corrugated sheet material. 
     The container may conveniently comprise a food or drinks container in which the inner compartment comprises a tub for containing food or drink and the outer compartment provides a receptacle for other food or drink which is held separately in the container when the container is sealed but which mixes or merges with the food or drink in the inner compartment when the lid is removed and the container extended to merge the compartments. 
     The container may be formed of plastics material. 
     The invention includes a container as aforesaid in combination with a lid in sealed engagement with the upper edges of the perimeter walls to close the container and isolate said first and second compartments. 
     The lid may comprise aluminum foil or a plastics film releasably bonded to the upper edges of the perimeter walls. The above container is conveniently made as a single unitary structure with the lid comprising a separate element. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view in section of a multicompartment container in accordance with the present invention in a sealed condition, 
     FIG. 2 is a plan view of the container with the lid removed, and 
     FIG. 3 is a side view in section with the lid removed and the container extended in depth in order to provide a single tub cavity. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The example shown in the drawings is particularly adapted for use in the food or drinks industry and may be conveniently used for products such as yoghurt or dessert products in which more than one constituent is held in isolation in the sealed condition but mixed on use. 
     The example shown in FIG. 1 comprises a central tub or pot  11  having an annular peripheral wall  12  formed integrally with a flat base  13 . The wall  12  tapers inwardly towards the base  13  and is open mouthed at the top with a circular shape in plan as shown in FIG.  2 . The tub  11  forms an inner compartment which is surrounded by an annular trough  15  extending entirely around the inner tub  11  and forming an outer compartment. The trough  15  has an outer peripheral wall  16  which in this example is a substantially vertical wall. It also has an inclined inner peripheral wall  17  formed as a flexible corrugated sheet which forms part of a folded structure with the outer peripheral wall  12  of the inner tub  11 . The outer trough  15  is also open mouthed at its upper end and has the same depth as the inner tub  11 . In this way the base  13  of the inner tub and the bottom of the trough  15  lie in the same plane and thereby rest in a stable manner when stacked or on a flat surface. The peripheral walls  16  and  17  of the outer trough  15  as well as the peripheral wall  12  of the inner tub  11  are formed as a single moulded sheet which has an overhanging lip  19  around the entire container. 
     The peripheral walls  12 ,  16  and  17  all have upper edges lying in a closure plane so as to provide sealing surfaces  20  on which a flat lid  21  sits in sealing engagement. Each of the sealing surfaces  20  is sufficiently wide, as shown in FIG. 2, and sufficiently rigid for the lid  21  to be pressed into sealing engagement with the top of the container and bonded thereto so as to seal in an isolated manner contents in the outer trough  15  and contents in the inner tub  11 . 
     In the sealed conditions shown in FIG. 1 the overall container has a depth indicated by that of the inner tub  11 . When the lid  11  is peeled away from the top of the container thereby breaking the seal with the sealing regions  20 , the container may be pulled to a different shape in order to increase its depth and merge the outer trough  15  with the inner tub  11 . The walls  12  and  17  form part of a folded arrangement with the fold line normally lying at the sealing surface  20  at the upper part of the wall  12 . When the tub  11  is pulled downwards relative to the outer walls  16  of the trough  15 , the folded wall structure may be progressively unfolded by the fold line progressively moving down the wall marked  17 . That is the pliable wall  17  which in this example is corrugated in order to provide increased flexibility and flow around the fold line at the junction between the outer trough  15  and the inner tub  11 . This movement may be continued until the position is reached shown in FIG. 3 in which the walls  12 ,  15  and  17  have become fully extended and substantially aligned forming a tapered outer wall of a single pot combining the original inner compartment  11  and the outer trough  15 . 
     It will be seen that the pot after extension in this way has a depth which is between two and three times the depth in the closed and sealed condition. 
     It will be appreciated that when used as a food container, the central tub  11  may be used for liquid or dry products. For example it could contain yoghurt or for example dry cereal. The outer trough  15  may be used for liquid sauces or for milk. 
     When used for food or drinks products, the container may conveniently be made of plastics material such as for example polypropylene. Alternatively waxed board or waxed paper may be used. The lids may be made of various materials such as for example aluminum or polypropylene foil or alternatively paper lids may be sealed against the container. 
     The material used for the container and the lid will be selected in accordance with the nature of the product to be held in the container. 
     The nature of the material and thickness used to form the walls of the container will be such that the walls are flexible enough to allow ease of movement between the sealed and extended positions while the external wall will be rigid enough to provide support for the entire structure when extended. The materials used may be adapted to withstand chilling or microwave treatment. 
     The invention is not limited to the details of the foregoing example. Although the particular example is shown where the two compartments are arranged concentrically one around the other, other designs may be used. The relative heights of the inner and outer compartments as well as their relative widths may be varied to suit the volume ratios required of the different constituents which are required in the container. 
     In the example shown in the drawings, the upper edges of the walls  12 ,  16  and  17  lie in the plane of the lid, referred to as a closure plane, which in that example is a flat horizontal plane. It will be understood that the reference to a closure plane is a reference to the plane of the lid which may in some examples have small deviations from flat, or horizontal. 
     The preferred example described in the drawings has a shape which allows the containers prior to filling and sealing to be stacked in a nested manner one extending inside another but other shapes may be used where necessary.

Technology Classification (CPC): 1