Patent attributes
The invention is a pump for dispensing liquid or semi-liquid product, designed and intended to be used in particular in the pharmaceutical or cosmetic field. The pump has a needle valve and a dispensing head manually movable on a pump housing between an inactive position and a dispensing position. The head includes a first cylinder forming a metering chamber for the pump, which draws in fluid from a container's reservoir by an intake tube and a check valve. A piston sealingly secured to the metering chamber pushes fluid through a passage into a second dosage chamber that is sealed from the dispensing orifice by a biased needle valve that is biased by a spring that is sealingly isolated from the second dosage chamber, the chamber that holds the elastic spring has a conduit that allows a user to test and verify that the second dosage chamber does not leak.