Patent ID: 7331491

Claim:
A container closure assembly comprising: a container neck having a first thread on an outer surface thereof; a closure for the neck, the closure having an opening therein, a skirt extending downwardly, and a second thread on an internal surface of the skirt for engaging the first thread on the container neck; and complementary valve elements on the neck and the closure, wherein the valve elements engage to provide a fluid-tight seal over the neck when the closure is fully secured on the neck, but the valve elements allow fluid from the neck to flow out through the opening when the closure is at an intermediate position at which the closure is still retained on the neck, and wherein the closure is moveable from the fully secured position to the intermediate position by relative rotation of the closure and the neck wherein the valve elements comprise: a tubular inlet extending downwardly from the opening in the cap, wherein the inlet comprises a circumferential sealing surface at the lower end thereof; and a complementary sealing plug having an apertured diaphragm extending across the inside of the container and forming a fluid-tight seal with the circumferential sealing surface when the closure is in the sealing position.