Reversibly collapsible/erectable container

Abstract

A foldable open-top container is constructed from a single sheet 1 of material having fold lines ( 4,7 ) enabling the sheet to be transformed into the container by folding. The container has a base ( 3 ) and side walls ( 16 ) that extend from the base and define a rim ( 5 ). The side walls are joined at each end by corners ( 11 ). Each corner is a flap formed from the two fold lines. The flap has an outside part ( 8 c ) that extends into one side wall, an inside part ( 8 b ) that extends into the adjoining side wall, and a middle part ( 8 a ) between the inside and outside parts. A first integral formation on one of said parts (notch 12 ) is interlocked with another of said parts (notch 14 ) to retain the flap in a folded condition.

1 . An open-top container constructed from a single sheet of material having a plurality of fold lines enabling said sheet of material to be transformed from a flat condition into said container by folding said sheet of material about said fold lines, said container comprising: 
 a base;    a plurality of side walls that extend from said base and define a rim of said container, said side walls being joined at each end thereof by corners, wherein each corner includes a flap formed from two fold lines extending from said rim and meeting at a point-junction with said base, said flap having an outside part that extends into one side wall and an inside part that extends into the adjoining side wall, and a middle part between said inside and outside parts; and    a first integral formation on one of said inside or outside part that is interlocked with a second integral formation on the other said inside or outside part, to retain said flap in a folded condition.    
   
   
       2 . A foldable container according to  claim 1 , wherein said first integral formation is a tag on said rim of said inside part of the corner, said tag is tucked into the space between said middle part and said outside part of the corner.  
   
   
       3 . A foldable container according to  claim 2 , wherein at least two corners are immediately adjacent one another to form a composite corner and said outside part of said adjacent corners of said composite corner adjoin each other.  
   
   
       4 . A foldable container according to  claim 3 , wherein there are at least three said composite corners.  
   
   
       5 . A foldable container according to  claim 1 , wherein said first integral formation is a first notch located in the rim of one of said inside and outside parts of the corner, said first notch is engaged with said second integral formation comprising a second notch located in said rim of the other of said inside and outside parts of said corner.  
   
   
       6 . A foldable container according to  claim 5 , wherein said rim of one of said inside and outside parts of said corner has a tab and said first notch is defined between said tab and one of said inside or outside parts, said first notch opening at the fold line between said inside or outside part and said middle part where it joins said rim.  
   
   
       7 . A foldable container according to  claim 6 , wherein said tab substantially fills the space between said side walls at the rim of said container when said flap is in its folded position.  
   
   
       8 . A foldable container according to any one of claims  5 ,  6 , or  7 , wherein both said first and said second notch has a root, said roots coinciding when said flap is in its folded position.  
   
   
       9 . A foldable container according to any of claims  5 ,  6 , or  7 , wherein said first and said second notches are aligned when said flap is in its folded position.  
   
   
       10 . A foldable container according to  claim 1 , wherein said first integral formation is a hook on said inside part of the corner, said hook being formed by a V-shaped cut in said inside part, which cut has two arms, said first arm proximate to said middle part extending to said rim and said second arm furthest from said middle part terminating at a distance from said rim, said second arm being aligned with the fold between said middle part and said outside part when said flap is in its folded position, said fold between said outside and said middle parts being relieved from said rim to a depth substantially coincident with the top of said second arm of said V-shaped cut when said flap is in its folded position, and so that said hook, when engaged with the fold between the middle and outside parts of said corner retains said flap in its folded condition.  
   
   
       11 . A foldable container according to  claim 10 , wherein said relieving of said fold between said outside and said middle part parts is achieved by cutting off said corner formed by said fold at said rim thereof.  
   
   
       12 . A foldable container according to any one of claims  10  or  11  wherein a hinge is formed between said hook and said inside part of said corner by a V-shaped fold line having a root and two limbs, the root coinciding with the top of said second arm of said V-shaped cut in said inside part, and said limbs extending to said rim.  
   
   
       13 . A foldable container according to  claim 12 , wherein one of said limbs of said V-shaped fold line is aligned with said second arm of said V-shaped cut.  
   
   
       14 . A foldable container according to  claim 13 , wherein the other of said limbs of said V-shaped fold line is substantially perpendicular to said second arm of said V-shaped cut.  
   
   
       15 . A foldable container according to  claim 1 , wherein said first integral formation is a wing formed on both said outside part and said middle part, said wing being formed by a fold line that extends from said rim of said middle part to the rim of said outside part, said second integral formation comprising a slot in the rim of said inner part, said inner part being relieved from the rim to a depth substantially coincident with the top of said outside and middle parts when said wing is in a folded condition, so that said slot when engaged with the wing, retains the flap in its folded condition.  
   
   
       16 . A foldable container according to  claim 1 , wherein said plurality of fold lines are defined between said base and said side walls, said fold lines extend between said point-junctions of adjoining corners.  
   
   
       17 . A foldable container according to  claim 1 , wherein said single sheet of material is substantially hexagonal in shape, when unfolded and flat.  
   
   
       18 . A foldable container according to  claim 1 , wherein said single sheet of material is a waterproof material.  
   
   
       19 . A foldable container according to  claim 18 , wherein said single sheet of material is a plastics material.  
   
   
       20 . A foldable container according to  claim 19 , wherein said plastics material is polypropylene.  
   
   
       21 . A foldable container according to  claim 1 , in the form of a bowl.