| 摘要 |
The invention relates to a metering pump comprising a pump barrel (1) housing a dose chamber (32) and control means that can be moved between a discharge position and a rest position. The inventive metering pump is characterised in that the control means comprise: a push rod (2); a piston (3) that can slide in relation to the push rod (2) and in relation to the pump barrel (1) all the while remaining in permanent contact with said two elements; and an elastically-deformable annular valve (4) that rests permanently against the push rod (2). The control means are moved between the rest position and the discharge position in two steps: the push rod (2) slides in relation to the piston (3) in the pump barrel; and subsequently the push rod (2) and the piston (3) slide jointly in the pump barrel (1) and a discharge opening (42) is released.
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