Closure device for hermetically sealing containers

Claim 1

In a closure device for providing a seal with a container having a shallow external bead in the region of the mouth-defining rim of the container, the closure device being of the type which comprises a panel, means defining a perimetric internal channel circumscribing the panel and forming a skirt beyond the channel, and a molding gasket formed of compressible plastic material reposing in the channel and extending along the internal surface of the skirt, the portion of the gasket extending along the internal surface of the skirt being provided with a plurality of internal projections, the improvement characterized by the features that each projection is separately formed integrally with said gasket with adjacent projections being circumferentially spaced from one another, that each projection has a shallow rectangular prismatic configuration, and that a lower portion of each of the projections being adapted to extend beyond the external bead on the container, whereby the closure device may be retained on the container in sealing relation therewith by the interengagement of the projections and the bead.