Container closure with external ribs

Abstract

An injection molded closure and a container has a closure with external ribs for preventing jamming together of adjacent closures in stacked relation, and facilitating self-alignment of stacked closures. The closure has a central circular panel and a sidewall extending generally upwardly therefrom. The sidewall has upper and lower vertical portions with a lateral offset portion extending therebetween, which define a plug-like portion of the closure. Upon engagement of the closure with a container, the plug-like section is inserted into the container opening. The ribs are spaced peripherally about the outside of the closure and include an upper closure-engaging surface for contact with the rim of another closure stacked therebelow, and a lower closure-engaging surface for contact with the lateral offset portion of the other closure stacked therebelow. The ribs prevent an upper closure from wedging or jamming into the plug-like portion of another closure therebelow, since the ribs will continue to engage with the upper rim and lateral offset portions of the lower closure to prevent downward movement of the upper closure into the plug-like portion of the lower closure. The outer ends of the lower closure-engaging rib surfaces are rounded, and the intersection of the lower portion of the sidewall and the lateral offset portion of the sidewall is rounded. These rounded surfaces bear and cam against one another to provide self-centering of non-centered closures.