| 摘要 |
<p>The invention relates to a pump of very simple low-cost structure comprising a hollow stem slidable within a cup-shaped body and acting as a compression piston, and a valving element consisting of an elongate rod movable in the cavity within the stem and provided with a conical collar which is urged by a spring to engage and seal against a conical seat within the stem, so that liquid delivery occurs snapwise when the conical collar disengages said conical seat within the stem. <IMAGE></p> |
