The invention concerns a dispensing and closure system arranged at the top of a container, in particular a soft tube comprising a liquid or pasty product, which is delivered by pressing on the tube. The invention is characterized in that it consists of a valve comprising two concentric elements, one of which forms a mobile cylindrical delivery valve and the other forms a cylindrical body exiting from a plate linked to the tube. The two elements defined between them an annular gap through which the product passes. When a manual pressure is exerted on the tube, it causes the product to act directly on the delivery valve causing the latter to open, countering an elastic return member, so as to allow the product to escape from the tube, when the pressure is exerted thereon and to automatically close the delivery valve when the pressure is released, preventing the possible return of the product already dispensed from returning inside the tube.
A one-way valve device comprises a valve seat arranged in the neck of a container that extends transversely across the interior of the neck and defines a plurality of passage openings. A pin-like projection is formed on the valve seat and extends axially to the exit opening. An elastic seal is held on the valve seat and comprises a sleeve-like section which surrounds the projection of the valve seat with the exception of its end section which rests on the end section of the projection. Applying pressure to the contents of the container axially displaces the sleeve-like part of the seal relative to the pin-like projection, so that the contents of the container can exit. In the closed position, an annular projection of an outer cap firmly presses the sleeve-like section of the seal against the projection of the valve seat, so that no container contents can exit.
