| 摘要 |
<p>A linear sheath valve (11) has a valve platform (33) and a conforming cover (21). An elastomeric membrane (29) is held under tension between the cover (21) and the valve platform (33) so as to control the flow of liquid between inlet and outlet channels (39, 45). The cover (21) includes an expansion area (23) on the cover surface adjacent to the membrane (29) and between the inlet (39) and the outlet (45). Liquid flows through the valve (11) when it is drawn by a vacuum. The vacuum operates on both the flow path exit, but also above the membrane (29), lifting it to open the flow path. Discontinuance of the vacuum allows the membrane (29) to seal the inlet (39) and outlet (45), thus again preventing any flow between them.</p> |
