Japan Crown Cork Co Ltd.

Toyo Seikan Kaisha, Ltd.

Takashi Yazaki

Fumio Mori

Junichi Itsubo

Osamu Ishii

Kiyoshi Kawaguchi

Isao Tanikawa

Isao Ichinose

Masayasu Koyama

Masao Ishinabe

Sumio Takeishi

Katsuake Tanaka

Plastic cap

A pilfer-proof plastic closure comprising a top panel wall and a cylindrical skirt wall extending downwardly from the peripheral edge of the top panel wall. The skirt wall has formed therein a circumferentially extending breakable line dividing the skirt wall into a main portion above the breakable line and a pilfer-proof bottom portion below it. The main portion has formed on its inner surface an internal thread and the pilfer-proof bottom portion has formed on its inner surface a plurality of radially inwardly projecting engaging flaps at circumferentially spaced positions. Each of said engaging flaps has a first portion extending from the inner surface of the pilfer-proof bottom portion and a second portion extending further from the forward end of the first portion inclinedly to the first portion in the closing direction of the closure for mounting the closure on the mouth-neck portion.

Pilfer-proof plastic closure for containers

A pilferproof plastic closure comprising a top panel wall and a cylindrical skirt wall extending downwardly from the peripheral edge of the top panel wall. A circumferential weakening line extending circumferentially is formed in the skirt wall, and the skirt wall is divided into a main portion above the weakening line and a pilferproof bottom portion beneath it. An internal thread to be screwably fitted with an external thread formed on the mouth-neck portion of a container is formed on the inner surface of the main portion, and a plurality of radially inwardly projecting and circumferentially spaced engaging flaps are formed on the inner surface of the pilferproof bottom portion. An axial breaking line is formed in the pilferproof bottom portion which extends downwardly from the upper end of the pilferproof bottom portion but is non-existent in at least a greater portion of the lower part of the pilferproof bottom portion. At least a greater portion of the base edge of each of the engaging flaps is positioned in the aforesaid lower part where the axial breaking line does not exist.

Plastic container closure having pilferproof characteristics

A pilfer-proof plastic closure comprising a top panel wall and a cylindrical skirt wall extending downwardly from the peripheral edge of the top panel wall. The skirt wall has formed therein a circumferentially extending breakable line dividing the skirt wall into a main portion above the breakable line and a pilfer-proof bottom portion below it. The main portion has formed on its inner surface an internal thread and the pilfer-proof bottom portion has formed on its inner surface a plurality of radially inwardly projecting engaging flaps at circumferentially spaced positions. Each of said engaging flaps has a first portion extending from the inner surface of the pilfer-proof bottom portion tiltedly in a direction opposite to the direction of rotation of the closure at the time of mounting it on the mouth-neck portion of a container and a second portion bent with respect to the first portion and further extending from the end of the first portion. The first portion forms an angle .alpha. smaller than 90 degrees and the second portion forms an angle .beta. larger than the angle .alpha., both with respect to the tangent of the inner surface of the pilfer-proof bottom portion at the base edge of the engaging flap.

Disclosed is a vessel closure provided with an easily openable liner, said liner being composed of an olefin resin or olefin resin composition comprising as a lubricant two different lubricants having different functional characteristics whereby the quantity of the lubricant immigrating to the surface of the liner is effectively controlled within a certain range at temperatures of a broad range and the opening torque of the closure is controlled at a low level at storage temperatures of a broad range.

Easily openable liner for vessel closures

Growing community of inventors

Hiratsuka, Japan

Takashi Yazaki