Patent ID: 6450375
Filing Date: 2002-09-17
Classification: B65D

Abstract:
A slit closure valve, including a membrane member made of a flexible material and having a first slit opening, said first slit opening being held in a closed configuration by resilient properties of the flexible material and placed into an open configuration against the resilient properties of the flexible material by a predetermined differential positive pressure being exerted on one of opposite sides of the membrane member, and further including a base member peripherally surrounding the membrane member, said base and membrane members being integrally formed as one piece of material, with said membrane member including a ridge portion in which said first slit opening is provided and a pair of inclined side wall portions extending from said ridge portion to a peripheral wall portion of the base member at acute angles of less than 90Â° between said peripheral wall portion and said inclined side wall portions, wherein said membrane member defines a second slit opening formed in at least one of said inclined side wall portions at a location near the peripheral wall portion, said second opening being held in a closed position by the resilient properties of the flexible material of said inclined wall portion but being placed into a releasing position by a differential negative pressure exerted on the membrane member from the same side thereof as was subjected to said predetermined differential positive pressure.