TAMPER-EVIDENT PLASTIC CLOSURE

摘要

A novel tamper-evident closure is taught for use in connection with a container having a neck portion having at least one thread, and an annular collar portion disposed below the neck portion. The closure includes a one-piece plastic closure body including a top end wall and a cylindrical side wall, the cylindrical side wall including an internally-threaded upper portion, and a depending lower skirt portion. The skirt portion includes an inwardly projecting bead adapted to engage the lower surface of the annular collar portion of the container when the closure is completely threaded onto the container. The closure further includes a frangible portion disposed above the skirt portion, the frangible portion including a substantially transverse line of weakness and being in the form of a bridge means having a substantially uniform thickness circumferentially around the closure but being sufficiently thin and flexible so as to be capable of collapsing when the inwardly projecting bead passes over the annular collar portion of the container as the closure is being applied to the container. The bridge means divides the cylindrical side wall to substantially aligned cylindrical side wall portions having substantially identical cross-sectional thickness above and below the bridge means. Upon collapse of the bridge means, the cylindrical side wall portions above and below the bridge means can abut against each other, thereby to permit the closure to be applied to the container without fracturing the bridge means. The bridge means is designed to fracture in substantially a transverse plane disposed above the annular collar portion of the container without causing fracturing of the skirt portion. Preferably, the closure is made of plastic material.