| 摘要 |
<p>The container (6) has openings (5) in its base controlled by a piston (3) linked by a rod (2) to a membrane (1) let into its upper surface. When the piston is actuated to allow the substance to flow out of the container, air is able to enter freely through holes (10, 11) at the top. The piston and rod can be made in one piece with the membrane or fastened to a thickened portion in the membrane's centre, and the piston has a shoulder (12) which acts as a stop in the maximum open position.</p> |
