| 摘要 |
A valve and method are provided wherein the valve has a membrane which is molded and cured in a naturally cupped or concave shape, but wherein the membrane is elastically inverted or deflected inside-out so that the direction of concavity is reversed. The membrane is positioned concentrically within a cylindrical or tubular dispensing spout so that the inverted membrane is cupped toward an exit direction of the spout. By inverting the membrane, a reliable radially-outward sealing bias is formed between a peripheral edge of the membrane against an interior of the tubular spout. When mounted on the bottom of a squeeze container, the valve is effective to dispense fluid from the container when squeezed, permit air to breathe back into the container after squeezing, and to sealably prevent leakage from the container. |
