| 摘要 |
A container (2, Fig.3) for storing and dispensing a liquid comprises a chamber for holding a liquid, the chamber being defined by rigid chamber walls (4, Fig.3); a liquid outlet port (10, Fig.3) for dispensing the liquid from the chamber; and a gas port 20 configured to allow air into the chamber from the atmosphere outside the chamber only when the pressure outside the chamber exceeds the pressure inside the chamber by more than a predetermined threshold. When liquid is dispensed from the container via its outlet port, the pressure within the chamber will be reduced. When the pressure within the chamber falls below the external, ambient pressure by more than a predetermined amount, the gas port will open to allow air into the chamber from the atmosphere. This allows liquid to continue to be withdrawn readily from the container, by preventing a significant pressure differential from building up between the inside and outside of the chamber. The gas port 20 may comprise a non-return valve which may be a duckbill valve 22 made from EPDM rubber or a perfluoroelastomer material. The non-return valve may be integrally formed with a pressure relief valve such as an umbrella valve (70, Fig.7). |
