Patent ID: 8322578

Claim:
A one-way valve for discharging a flowable material from a container of a reducible volume, comprising: an independent valve seat which is positioned in an opening defined by a neck of the container and comprises a base body which rests on an inner wall of the container neck and contains at least one through hole, and a projection having an end section, said projection extending axially from said base body; an elastic seal which comprises a flexible annular section seated on said at least one through hole, and a sleeve-like section extending axially from said annular section and having an end section, said sleeve-like section surrounding the projection at a radial distance with the exception of its end section; and a non-removable cap configured to enclose said valve seat and said seal and defining an exit opening, wherein when the one-way valve is in a closed state, said flexible annular section is seated on said at least one through hole to seal said at least one through hole and prevent contaminants from entering the container through said at least one through hole and said end sections of said projection and said seal are positioned in said exit opening and are in engagement to seal said exit opening, and when the one-way valve is in an open state, a portion of said flexible annular section flexes upwardly away from said at least one through hole and said end section of said seal moves upwardly out of said exit opening to dis-engage said end section of said seal from said end section of said projection to allow the material to pass through said at least one through hole and be discharged from said exit opening, said sleeve-like section of said elastic seal forming a seal between said projection and a space under said cap for preventing the material from remaining in said space after it is discharged from said exit opening.