Patent attributes
A device for dispensing and receiving a liquid or semi-liquid product via a metering chamber of a pump body. The device includes a piston which is fixably mounted in the pump body and is provided with an end sealingly engaged into the chamber. The piston end is provided with an elastically deformable membrane put thereon. The membrane includes a transversal wall forming an input check valve which is provided with a central supply orifice sealingly closable by a protruded element forming the check valve seat on the end of the piston. The membrane includes a fixing cylindrical skirt which is provided with at least one sealing peripheral lip slidingly contacting the internal wall of the chamber. The skirt forms a valve when it is deformed by contact with a projection bearing by the internal wall of the chamber in such a way that the air compressed by the piston is released into the chamber by the pump priming.
