| 主权项 |
1. A metering device securable to a container adapted to contain a fluid for transferring, from an upstream space towards a downstream space, a predetermined volume of the fluid in response to a rise in pressure of the fluid in the upstream space, this device comprising:
at least a hollow body, a buoyant valve, and a sealing seat defined over a hollow or substantially annular member and surrounding a fluid passage disposed between the upstream space and the downstream space, the hollow body delimiting at least partially a chamber provided with an inlet and an outlet, the buoyant valve being movable with respect to the hollow body between a rest position, towards which the buoyant valve is biased by a return force, at least partially comprising buoyancy, and an end position, which is spaced from the rest position and towards which the valve is dragged by the fluid flowing from the upstream space towards the downstream space due to the rise in pressure, and in which the valve rests on the sealing seat, the upstream space extending at least outside the chamber on its inlet side, the downstream space extending at least outside the metering device and the chamber on its outlet side, the valve isolating one from the other the upstream space and the downstream space in its end position and only in this position, and the outlet of the chamber communicating with the upstream space for any position of the valve other than its end position, wherein, once the rise in pressure is released, air enters the container via the outlet of the chamber. |
