Pilfer-proof plastic closure for containers

摘要

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.