Patent ID: 8376164

Claim:
A cap without additional seal for closing an opening at a neck of a container, the cap comprising: a closing disc; a peripheral skirt sized to fit around the neck, the peripheral skirt having an internal surface provided with engaging means for engaging the neck of the container to thereby allow attachment of the cap onto the neck; a first annular sealing lip projecting downwardly from under the closing disc, near the opening at the neck, the first annular sealing lip being folded against the neck and toward the opening when the cap is attached, to thereby allow neutralization of any backwash effect when the container is moved; and a second annular sealing lip external to the first annular sealing lip and positioned so as to be also folded against the neck, in a direction opposite to that of the first annular sealing lip when the cap is attached onto the neck; wherein the second annular sealing lip also projects downwardly from under the closing disc, around the first annular sealing lip, the second annular sealing lip being further provided with a plurality of teeth or protrusions positioned radially outwardly of the first sealing lip to interact with and form several contact points on a radially outwardly convex surface on the neck when the second lip is in a folded position, thus forming a plurality of sealing barriers with a staircase effect, the teeth or protrusions thereby matching a shape of the neck and absorbing surface defects, and wherein the peripheral skirt has an upper internal portion provided with a groove which forms, by its position, a third lip external to the first and second lips, wherein the third lip interacts with the radially outwardly convex surface of the neck, the third lip creating a radial tension, applying a pressure onto the cap when the cap is attached to the neck, and ensuring a tightening of a tension ring of the cap to an annular bead external to the neck, with a compression that occurs when the first and second lips are in a folded position, and with an additional contact point being formed with the neck.