| 摘要 |
<p>A micropump for delivering metered doses of liquid comprises a capillary cylinder in which is movably mounted a piston. The cylinder is mounted in a plastics block with a spool valve slidably movable between first and second positions. In the first position an inlet line communicates with the cylinder chamber and upward movement of the piston causes a column of air and a column of liquid to be drawn in. The valve is then moved to its other position whereby downward movement of the piston expels the metered dose of liquid out through an outlet.</p> |
