| 摘要 |
<p>The dispenser piston (18) has a pair of spaced apart, annular seals (36, 37), which contact the inner wall of the cylinder (22) in a liquid-tight relation. A first vent (34) extending axially of the cylinder (22) and communicating with the interior of the container (12) from which liquid is dispensed is formed in the cylinder (22). When the piston (18) is in the at rest position, the vent (34) communicates with the space defined between the seals (36, 37) and the cylinder (22), and when the piston (18) is in the dispensing position the vent (34) communicates with the atmospheric air to prevent negative pressure being created in the container (12). A circular member (72) for suppressing liquid leakage through the vent (34) is fitted in the container cap (20) and defines a chamber (71). A second vent (82) is formed in the suppressing member (72).</p> |
