Patent ID: 7530469

Claim:
A valve device for preventing unintentional fluid outflow from a drinking container, the device being underpressure-activated and, when in position of use, being connected to an outflow opening in the container, wherein the device consists of two flexible pressure-sensitive membranes constituting an outer membrane and an inner membrane, respectively, that are placed at an axial distance from one another, and their peripheral attachment areas are pressure-sealingly interconnected, the constellation of which defines an intermediate reference pressure chamber, and that the chamber is provided with at least one vent placed outside of the activation surfaces of the membranes and in communication with an ambient pressure P 1 , and that one of the two membranes is fixedly connected to a through-put flow pipe for said fluid, and that the other of the two membranes is provided with a through-going membrane opening within which the pipe is movably arranged, and that the membrane opening is associated with a primary sealing body arranged to seal against fluid flow via the pipe, and with a secondary sealing body arranged to provide a seal between the chamber and an internal pressure P 3 in the container, and that both sealing bodies are placed in pressure-sealing contact with the pipe when the valve device is in an inactive position of rest, while at least the primary sealing body is placed in an open position when the valve device is in an active position, the valve device being activated by applying an underpressure P 2 to the outside of the outer membrane and moving it relative to the inner membrane.