| 摘要 |
<p>A liquid metering device comprising a pumping chamber 16 communicatable with a suction duct 5 and a discharge duct 24, a main piston 21 housed in said pumping chamber, a member 27 having a sealing portion 28 for the discharge duct 24 and an opposed portion as a secondary piston 29 housed in a counterchamber 19 in which there are resilient means 34 biassing the secondary piston 29, there being first passage means 39, 40 for establishing a direct communication between the suction duct 5 and the pumping chamber 16 and second passage means 41, 42 placing the interior space of the container in direct communication with the counterchamber 19. <IMAGE></p> |
