| 摘要 |
<p>A tap assembly (10) for a container of liquid comprises a delivery spout (11) molded of a gas impermeable plastic and a unitary dispenser closure (20) molded of an elastomeric material having the required resiliency for valve operation. The spout (11) has a neck (12) which opens outwardly into a hemispherical bowl (15) terminating in a rim (16) and having an opening providing a dispensing port. The closure (20) has a bowl-shaped diaphragmic wall (25) which snaps onto the rim (16) and seat in the bowl of the spout (11) in a closed-valve position as a seal across the neck and port openings. An integral toggle (29) projects axially forwardly from the bottom of the bowl-shaped wall (25) for finger manipulation to distort the latter from the closed-valve position to an open valve position of partially unseated configuration for dispensing liquid from the container. A plug (30), molded of a gas impermeable plastic, forms a temporary gas barrier and comprises a stopper portion (31) sized to fit the neck of the spout (11) and a forward extension which projects into a hollow (29a) formed in the toggle (29). The toggle (29) is also depressible inwardly to dislodge the plug (30) into the container preparatory for use. Alternatively, a flexible disk (70) having gas impermeable properties is permanently mounted on the interior side of the bowl-shaped wall of the closure, moves therewith from closed to open valve positions, and coacts with the spout as the gas barrier when closed.</p> |
