| 摘要 |
A container for fluid including a front flexible wall and a rear flexible wall sealed together along marginal portions thereof to define a body for holding fluid and unsecured along other portions thereof to provide a fluid supply opening. A valve is positioned in said supply opening between the front and rear walls, to provide a fluid inlet passageway when the valve is in an open condition and to close the fluid inlet passageway when the valve is in a closed condition. The valve comprises a flexible inner sheet and a resilient or spring sheet opposed to each other. The inner sheet is normally in contact with the spring sheet for closing the inlet passageway. The inner sheet and spring sheet extending outward from each other upon the application of an external force for opening the fluid inlet passageway, so that fluid may pass between the inner sheet and the spring sheet and into the body of the container. Pockets are provided inside the container adjacent the valve for tightening the contact of the inner sheet and spring sheet during the valve closed condition, in the event fluid flows back toward the valve. Fluid inserted into the container pulls the rear wall more taut to tug against the spring sheet. This causes the spring sheet in response to arc and thereby form a convex surface or maintain a convex arc, for forcing the inner sheet into a tight and sealing concave contact with the convex surface of the spring sheet.
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