| 摘要 |
<p>A regulator is provided for controlling the degree of suction within a collection chamber in a drainage device. The regulator includes a means for measuring the degree of negativity within the chamber and a feedback passageway leading from the measuring means to the suction source. When the measuring means detects a degree of negativity which is equal to or greater than a predetermined value in relation to the available suction the feedback passageway is opened to atmosphere and when the degree of negativity becomes less than the predetermined value the feedback passageway is closed so as to impose the full suction of the suction source upon the chamber.</p> |
