摘要 |
A pneumatic evacuation pump includes an inlet assembly having an inlet valve, a charging port, and purge air injection means. A chamber includes a charge end opening to the charging port, and a discharge end. A delivery assembly includes a passage between the discharge end and a delivery outlet, a delivery valve interposed in the passage between the discharge end and the delivery outlet, and a venturi vacuum source opening to the passage between a discharge valve and the discharge end. Exhaust air injection means located downstream of the discharge valve utilizes exhaust air from the venturi vacuum source. A compressed air supply supplies the venturi vacuum source and the purge air injection means. Control means acts to coordinate a cycle of operation of the venturi vacuum source, the purge air injection means, the exhaust air injection means and the inlet and delivery valves. |