Bottles in semi-rigid plastic material

Claim 1

An improved collapsible semi-rigid plastic bottle for containing and dispensing physiological liquids for intravenous administration of the type having four sidewalls joined at their respective ends by two opposed transversal walls to form a base and a narrowing top surface, said top surface containing at least one access device to the inside volume of said bottle, with two opposite sidewalls containing a bellows-shaped groove extending substantially the entire length of said sidewalls and said base also containing a bellows-shaped groove joined at each end to the bellows-shaped grooves of the attached sidewalls such that when under an internal-external pressure differential the remaining two flat sidewalls of said bottle collapse toward each other, wherein the improvement comprises a flexible hanging means oppositely attached to two edges formed by the joining of said base to said flat sidewalls so that, when said bottle is hanging in an inverted position, the weight of said bottle exerts a force on said flexible hanging means which, as a result of the positioning and flexing of said hanging means, materially aids in the collapse of said flat sidewalls.