Gasketless Closure For Open-Top Pails

Abstract

A molded plastic closure is configured to provide a plug fit with the top rim of an open top container having an outwardly protruding rim flange. A two-part seal preventing leakage of fluid from the container is provided by means of a ridge structure on the inner wall of the inverted U-shaped channel of the closure peripheral structure as well as a flexible sealing wiper appendage which is formed integrally with the top of the inverted U-shaped structure and which deformingly contacts the top surface of the container rim when the rim is essentially fully inserted into the U-shaped channel. The wiper appendage is formed to angle toward the inner channel wall in the undeflected condition.

What is claimed: 
     
         1 . A closure for a pail having a sidewall ending in an outwardly protruding top rim having a substantially flat top surface and a substantially flat undersurface wherein said closure comprises:
 a molded plastic body having a center deck and an integral annular peripheral channel portion with radially spaced apart inner and outer annular walls defining an inverted annular U-shaped channel having an interior inner top and outer surfaces for lockingly receiving said top rim and a portion of said sidewall therein;   said outer wall having an annular ledge to lockingly abut the under surface of said outwardly protruding annular rim when the pail rim is inserted into said annular channel;   said interior inner surface having annular sealed ridges formed thereon to lie sealingly against an inner sidewall surface of said pail to form a first seal; and   a sealing wiper appendage integrally depending from the interior top wall of said inverted U-shaped channel and angled downwardly and inwardly toward said interior inner surface so as to deformingly contact the top surface of said outwardly protruding rim when said rim is inserted into said channel to form a second seal with said container.   
     
     
         2 . A closure as defined in  claim 1  wherein the entirety of the closure is molded from high density polyethylene (HDPE). 
     
     
         3 . A closure as defined in  claim 1  wherein the sealing wiper appendage has a root and a length and wherein the ratio of the length dimension to the root dimension is approximately 4.25:1. 
     
     
         4 . A closure as defined in  claim 3  wherein the length of the appendage is about 0.170″. 
     
     
         5 . A closure as defined in  claim 1  wherein the wiper appendage angles inwardly toward said inner wall by about 20°.