| 摘要 |
<p>The invention concerns a vacuum pumping circuit comprising: an upper chamber (34) and a lower chamber (36) communicating via a connecting orifice (38), and comprising a valve (40) provided with a rod slidably guided along a vertical axis (A1) to close the connecting orifice (38). The invention is characterized in that the valve rod (48) is provided with a section forming a piston (52) which forms the mobile upper wall of a control chamber (54) communicating with the upper chamber (34), the piston (52) including an upper surface (56) subjected to the pressure of atmospheric air and a lower surface (58) subjected to the pressure prevailing in the control chamber (54). The invention also concerns a machine equipped with said pumping circuit.</p> |
