| 摘要 |
A pump of type comprising a moving member mounted to move relative to a support, the moving member having a central duct into which the substance to be dispensed penetrates via at least one opening, the support co-operating with the moving member to define a variable volume pump chamber around said central duct, the pump also having a diaphragm having a central portion in which said central duct is inserted, the diaphragm being organized in such a manner as to isolate the pump chamber from the opening(s) of the central duct when the volume of the pump chamber increases and the substance is sucked into it. At least one of the central duct and the central portion of the diaphragm includes an annular bulge that is suitable, when the volume of the pump chamber increases, for bearing in leakproof manner on the other of the central portion and the central duct of the diaphragm, so as to isolate the pump chamber from the opening(s) of the central duct.
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