Japan Crown Cork Co Ltd.

Tomoya Igarashi

Tateo Kubo

Hidehiko Ohmi

Kouzo Nakamura

A plastic container closure comprising a top panel, a skirt portion, an annular protruded portion that is formed inwardly from the inner surface of the top panel and on the inside of a portion near the root of the skirt maintaining a small gap therebetween, and a sealing liner that is fitted by press-molding on the inside of the top panel, wherein a substantially vertical portion is formed on said liner along the inner surface of the annular protruded portion, and sealing performance is maintained by the engagement between the outer edge of the mouth of the container and the substantially vertical portion. Since the sealing is accomplished over a surface having a predetermined width in the up-and-down direction, the sealing performance is not impaired even when the top panel is deformed by the pressure. Moreover, favorable sealing performance is maintained even against shock that is given to the container at the time of fitting the closure.

Method of producing a plastic container closure

Plastic container closure with high sealing precision

A container closure includes a plastic shell, and a liner molded by fluidizing a plastic material within the shell. Depressions are formed at circumferentially spaced positions at an upper end portion of the inner peripheral surface of the skirt wall. The depressions each have a circumferential length increased radially outwardly at least in part thereof. A plurality of projections are formed on the outer peripheral surface of the liner in correspondence with the depressions.

Container closure with a plastic liner having projections extending into

An internal thread is formed on the inner peripheral surface of a skirt wall in a container closure of a plastic. The cross-sectional shape of the internal thread is defined by an upper side edge extending radially inwardly in an axially downwardly inclined manner, a lower side edge extending radially inwardly in an axially upwardly inclined manner, a front edge extending substantially vertically, two concave arcs, and two convex arcs.

Growing community of inventors

Hiratsuka, Japan

Tomoya Igarashi