US 4,343,408 AGranted

Tamper-evident plastic closure

AssigneeGeneral Kap (P.R.) Corporation

InventorErnest J. Csaszar

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Abstract

Tamper-evident closures which are useful in conjunction with various bottles and containers are disclosed. The closures are intended to be used in connection with containers having threaded necks above an annular collar, and they comprise one-piece closures including an end wall, an internally threaded upper portion and a depending lower skirt portion which includes an inwardly projecting bead adapted to engage the annular collar on the container. The depending lower skirt portion has a substantially uniform thickness throughout its entire area intended to contact the annular collar on the container, and theclosure includes an area of weakness which is designed to fracture in a substantially horizontal plane across the closure or, in another embodiment, in a plane which neither passes through nor is tangential to the annular collar on the container. Fracture thus occurs when the closure is unthreaded from the container, thereby leaving the lower skirt portion engaged to the annular collar on the container after the end wall and internally threaded upper portion of the closure have been removed.

Claims27

Dependent claims

A tamper-evident closure for use in connection with a container including a threaded neck portion and an annular collar portion below said threaded neck portion, said closure comprising a one-piece closure body including an end wall and a cylindrical side wall, said cylindrical side wall including an internallythreaded upper portion, a depending lower skirt portion, and an intermediate side wall portion therebetween, said depending lower skirt portion including an inwardly projecting bead adapted to engage the lower end of said annular collar portion of said container when said closure is completely threaded onto said container, said cylindrical side wall including a frangible portion comprising a circumferential groove formed on the outer surface of said closure to thereby uniformly substantially reduce the thickness of said intermediate side wall portion of said closure at a predetermined location on said intermediate side wall, said predetermined location being located above said inwardly projecting bead so as to divide said intermediate side wall portion into a first intermediate side wall portion located above said predetermined location and a second intermediate side wall portion located below said predetermined location, said first and second intermediate side wall portions being in substantial alignment with each other in the plane of said cylindrical side wall, said frangible portion therefore having a substantially uniform thickness circumferentially around said closure, and being designed to fracture in a substantially horizontal plane across said closure when said closure is unthreaded from said container so as to leave said depending lower skirt portion and said second intermediate side wall portion engaged to said annular collar portion after said internally threaded upper portion and said first intermediate side wall portion of said closure have been unthreaded from said container.

A tamper-evident closure for use in connection with a container including a threaded neck portion and an annular collar portion below said threaded neck portion, said threaded neck portion including threads having a maximum thread diameter, said closure comprising a one-piece closure body including an end wall and a cylindrical side wall, said cylindrical side wall including an internally-threaded upper portion, a depending lower skirt portion, and an intermediate side wall portion therebetween, said internallythreaded upper portion having threads which project inwardly from the inner surface of said cylindrical side wall, said depending lower skirt portion including an inwardly projecting bead adapted to engage said annular collar portion of said container when said closure is completely threaded onto said container, said inwardly projecting bead projecting inwardly to a point substantially no further than a plane corresponding to said inner surface of said cylindrical side wall so that said closure can be applied to said container substantially without interference from said maximum thread diameter of said threaded neck portion of said container so that said closure can be applied to said container without breaking prematurely, said cylindrical side wall including a frangible portion comprising an area of weakness designed to fracture in a substantially horizontal plane across said closure at a predetermined location on said intermediate side wall portion when said closure is unthreaded from said container, said predetermined location dividing said intermediate side wall portion into a first intermediate side wall portion located above said predetermined location and a second intermediate side wall portion located below said predetermined location, said first and second intermediate side wall portions being in substantial alignment with each other in the vertical plane of said cylindrical side wall, thereby leaving said depending lower skirt portion and said second intermediate side wall portion engaged to said annular collar portion after said internally threaded upper portion and said first intermediate side wall portion of said closure have been unthreaded from said container.

Dependencies are inferred from the claim text.