초록 ▼

A container is provided in the form of a cup-like container body with a round mouth closed by a lid which becomes removably replaceable upon tearing away of a circumferentially extending tear strip which initially surrounds the mouth rim of the container body as a radially outer, integral part of th

A container is provided in the form of a cup-like container body with a round mouth closed by a lid which becomes removably replaceable upon tearing away of a circumferentially extending tear strip which initially surrounds the mouth rim of the container body as a radially outer, integral part of the lid flange. As the lid is differential pressure-thermoformed, its radially outer region is formed into a generally inverted U-shaped structure which near the juncture of the base and radially outer leg of the inverted U, is provided, within the channel, with an inverted V-shaped notch of substantially diminished wall thickness to provide a line of weakness which preferably extends nearly fully around the circumference of the lid, but for at an angularly short tear-starting site. After the thermoforming step, and preferably in connection with trimming the lid from the surrounding scrap portion of the sheet in which it was formed, a mechanical crimper axially collapses an initially radially outwardly concave annular portion of the radially outer leg of the inverted U, intermediate the vertical extend of that leg, with an upwardly, inwardly directed barb or hook which, cooperating with the rim of the cup provides the snap lock feature for securing the lid to the cup. After the initial lidding, it is this barb which prevents removal of the lid until the tear strip is torn away.

대표청구항 ▼

A method for making a tamper-evident lid for a container body having an upstanding peripheral sidewall providing a mouth defined at least in part by a rim having an outer portion which projects downwardly and terminates in a lower end, comprising: providing a sheet of thermoplastic resin; differenti

A method for making a tamper-evident lid for a container body having an upstanding peripheral sidewall providing a mouth defined at least in part by a rim having an outer portion which projects downwardly and terminates in a lower end, comprising: providing a sheet of thermoplastic resin; differential pressure-thermoforming a site on said sheet to provide a potential lid having a central disk-shaped portion perimetrically surrounded by an inverted U-shaped channel portion having a radially inner wall, a top wall and a radially outer wall; providing a circumferentially extending radially inwardly convex bulge in said radially outer wall of said U-shaped channel portion at an axially intermediate level thereon; while supporting said U-shaped channel portion against axial collapse, mechanically compressing said radially outer wall below said convex bulge axially towards said top wall and thereby telescoping and permanently deforming said convex bulge to provide a barb which projects inwardly towards said inner wall of said U-shaped channel portion sufficiently to catch under said lower end of said rim, when said channel portion is pushed onto said container body so as to enclose said rim from above, with sufficient interference as to normally prevent non-destructive removal of said channel portion from said container body.