Patent ID: 7637417

Claim:
A foldable vessel for holding a liquid comprising a plastic sheet having a plurality of sides defining a perimeter edge of said sheet; a series of scored folding lines defining a closed shape at a central region of said plastic sheet having a number of sides corresponding to the sides of the perimeter edge of said plastic sheet and extending in the same general direction as a respective side of said perimeter edge; a pair of scored folding lines diverging out from each corner of said closed shape to said perimeter edge to form a series of triangular flaps so that when opposite pairs of vessel sides defined between said triangular flaps are folded up, said triangular flaps can be folded over onto one of said adjacent sides and an extension region of the other adjacent side wrapped over said triangular flap to form a rounded corner; further including a mating set of snaps at the top of at least two sets of said side extension regions and adjacent sides in an extension region covered by one of said triangular flaps, with an aligned clearance hole formed in each triangular flap wrapped over by a respective extension region to allow securement of said wrapped condition thereof by mating of said snaps through said clearance hole, the improvement comprising an outwardly curving upper perimeter edge of at least one pair of opposite sides and an inwardly curving perimeter edge on the other pair of opposite sides so that said lower and upper edges define a rim of said folded vessel, the mating snap sets located at a higher level region of said rim when said vessel is folded up to ensure that liquid cannot reach the level at which said mating snap sets are located.