| 摘要 |
<p>A cap (10) is described for closing a liquid beverage container for allowing the beverage to be sucked oat of the container through a spout (20), while preventing spillage when no suction takes place. A demand valve (16,18) is incorporated into the cap, which has an inlet port (184,186) communicating with the interior of the container, a discharge port communicating with the spout and a control port communicating with the ambient atmosphere through a hole (101) in the cap. In the invention, the demand valve is formed by two members that are mounted on the inner surface of the cap. The first member (18) is rigid and defines the valve inlet port and a valve seat (184). The second member (16) incorporates a valve closure element (164) and a resilient membrane which includes the valve closure element and serves as a pressure sensitive diaphragm. The second member also seals against the first member.</p> |
