Internal, multi-seal plastic closure

Abstract

A closure that includes a top panel and a skirt extending downwardly from a peripheral edge of the top panel is provided. The closure includes a tamper band which extends downwardly from the skirt and a multi-seal, seal portion which is located inside of the closure above the threads where the top panel is joined to the skirt. The tamper band and seal portion are configured to improve the removability of the closure from a mold.

What is claimed is: 
     
         1 . A single-piece, molded, plastic, closure comprising:
 a circular, closure panel having an internal surface;   a cylindrical skirt extending from the top panel to a tamper band attached thereto, the skirt including a plurality of external raised ribs and an interior threaded portion engageable with respective threads on a container; and   a seal portion including an inclined seal ring extending from the internal surface and concentric with the skirt, a vertical seal ring extending from the internal surface between the inclined seal ring and the skirt and concentric with the skirt, and a top-edge seal ring extending from the internal surface between the inclined seal ring and the vertical seal ring, the inclined seal ring extending further than the vertical and top-edge seal rings, and vertical seal ring extending further than the top-edge seal ring,   the inclined seal ring including a first flat wall facing away from the skirt, and a first seal wall facing toward the skirt, the first seal wall including a first contact ring which creates a first seal with an associated container, the first seal wall including a first wall portion extending from the interior surface toward the first contact ring, the first flat wall extending from the internal surface at a first angle between 95 and 115 degrees, with a second angle between the first wall portion and the interior surface being less than the first angle,   the vertical seal ring including a second flat wall facing toward the skirt, and a second seal wall facing away from the skirt, the second seal wall including a second contact ring which creates a second seal with an associated container, the second seal wall including a second wall portion extending from the interior surface toward the second contact ring, the second flat wall extending from the internal surface at a third angle between 85 and 90 degrees, with a fourth angle between the second wall portion and the interior surface being greater than the third angle.   
     
     
         2 . The closure of  claim 1 , wherein the first angle is 105 degrees. 
     
     
         3 . The closure of  claim 2 , wherein the second angle is 102 degrees. 
     
     
         4 . The closure of  claim 1 , wherein the third angle is 88 degrees. 
     
     
         5 . The closure of  claim 4 , wherein the fourth angle is 110 degrees. 
     
     
         6 . The closure of  claim 1 , wherein the plurality of raised ribs are each symmetric about a radial line extending through the center of each of the plurality of raised ribs. 
     
     
         7 . The closure of  claim 1 , wherein the first seal wall includes a first rounded portion which has a first radius of between 0.065 and 0.075 inches and the first contact ring lays on the first rounded portion. 
     
     
         8 . The closure of  claim 7 , wherein the first radius is 0.07 inches. 
     
     
         9 . The closure of  claim 1 , wherein the second seal wall includes a second rounded portion which has a second radius of between 0.025 and 0.035 inches and the second contact ring lays on the second rounded portion. 
     
     
         10 . The closure of  claim 9 , wherein the second radius is 0.03 inches. 
     
     
         11 . A single-piece, molded, plastic closure, comprising:
 a circular panel having an interior surface and a peripheral edge;   a generally cylindrical skirt extending from a peripheral edge of the transition section such that the skirt is substantially perpendicular to the top wall, the skirt including a threaded portion on the interior thereof;   a foldable tamper band extending from the cylindrical skirt;   a plurality of raised ribs extending outwardly from an outer surface of the skirt and extending axially along at least a portion of the skirt;   an inclined ring extending from the internal surface and concentric with the skirt, a vertical ring extending from the internal surface between the inclined ring and the skirt and concentric with the skirt, and a ridge extending from the internal surface between the inclined ring and the vertical ring, the inclined ring extending further than the vertical ring and the ridges, and vertical ring extending further than the ridge,   the inclined ring including a first flat wall facing away from the skirt, and a first seal wall facing toward the skirt, the first seal wall including a first contact ring which creates a first seal with an associated container, the first seal wall including a first wall portion extending from the interior surface toward the first contact ring, the first flat wall extending from the internal surface at substantially 105 degrees, with a first angle between the first wall portion and the interior surface being less than 105 degrees,   the vertical seal ring including a second flat wall facing toward the skirt, and a second seal wall facing away from the skirt, the second seal wall including a second contact ring which creates a second seal with an associated container, the second seal wall including a second wall portion extending from the interior surface toward the second contact ring, the second flat wall extending from the internal surface at 88 degrees, with a second angle between the second wall portion and the interior surface being greater than 88 degrees.   
     
     
         12 . The closure of  claim 11 , wherein the second angle is 102 degrees. 
     
     
         13 . The closure of  claim 12 , wherein the fourth angle is 110 degrees. 
     
     
         14 . The closure of  claim 11 , wherein the first seal wall includes a first rounded portion which has a first radius of between 0.065 and 0.075 inches and the first contact ring lays on the first rounded portion. 
     
     
         15 . The closure of  claim 14 , wherein the first radius is 0.07 inches. 
     
     
         16 . The closure of  claim 14 , wherein the second seal wall includes a second rounded portion which has a second radius of between 0.025 and 0.035 inches and the second contact ring lays on the second rounded portion. 
     
     
         17 . A sealed container comprising:
 a container including an opening surrounded by a hollow cylindrical neck having an interior cylindrical wall, an exterior cylindrical wall, a sealing surface extending therebetween, and a threaded portion on the exterior wall extending to an unthreaded portion of the exterior wall adjacent to the sealing surface; and   a one-piece, plastic closure including:   a circular, closure panel having an internal surface;   a cylindrical skirt extending from the top panel to a tamper band attached thereto, the skirt including a plurality of external raised ribs and an interior threaded portion engageable with respective threads on a container; and   a seal portion including an inclined seal ring extending from the internal surface and concentric with the skirt, a vertical seal ring extending from the internal surface between the inclined seal ring and the skirt and concentric with the skirt, and a top-edge seal ring extending from the internal surface between the inclined seal ring and the vertical seal ring, the inclined seal ring extending further than the vertical and top-edge seal rings, and vertical seal ring extending further than the top-edge seal ring,   the inclined seal ring including a first flat wall facing away from the skirt, and a first seal wall facing toward the skirt, the first seal wall including a first contact ring, the first seal wall including a first wall portion extending from the interior surface toward the first contact ring, the first flat wall and the internal surface extending from the internal surface at a first angle between 95 and 115 degrees, with a second angle between the first wall portion and the interior surface being less than the first angle,   the vertical seal ring including a second flat wall facing toward the skirt, and a second seal wall facing away from the skirt, the second seal wall including a second contact ring, the second seal wall including a second wall portion extending from the interior surface toward the second contact ring, the second flat wall extending from the internal surface at a third angle between 85 and 90 degrees, with a fourth angle between the second wall portion and the interior surface being greater than the third angle;   wherein when the container is fully engaged with the interior threaded portion of the closure, the first contact ring forms a seal with the interior cylindrical wall of the container, the second seal ring forms a seal with an edge at which the sealing surface meets the unthreaded portion of the container, and the top-edge seal ring forms a seal with the sealing surface of the container, wherein the angles recited above change when the closure is sealed to the container.   
     
     
         18 . The container of  claim 17 , wherein the first seal wall includes a first rounded portion which has a first radius of between 0.065 and 0.075 inches and the first contact ring lays on the first rounded portion. 
     
     
         19 . The container of  claim 18 , wherein the second seal wall includes a second rounded portion which has a second radius of between 0.025 and 0.035 inches and the second contact ring lays on the second rounded portion. 
     
     
         20 . The container of  claim 19 , wherein the first and second become smaller when the closure is fully engaged with the container and the third and fourth angles become larger when the closure is fully engaged with the container.