Container lid with ring and method of manufacture

Abstract

A container lid is provided having a lid insert constructed of a paper-based material and a peripheral ring constructed of a plastic material. The ring is configured to be separated from the lid insert upon disposal. The lid insert includes a peripheral rim extending outwardly from a central cover portion. The ring includes an outwardly extending flange and a skirt depending downwardly from the flange. A first undercut extends inwardly from the skirt defining a channel sized and shaped for receiving an outer edge of the lid insert's peripheral rim. The channel may alternatively be sized and shaped for also receiving an outer edge of a peripheral rim of a container base to which the lid is attached. Another embodiment includes a second undercut located beneath the first undercut and defining a second channel into which an outer edge of the rim of the container base may be received.

What is claimed is: 
     
         1 . A container lid adapted to interlock with a container base having a peripheral rim, said lid comprising:
 a lid insert including a central cover portion and a generally flat and horizontal peripheral rim extending outwardly around at least part of said cover portion;   a ring circumscribing at least part of said lid insert rim, said ring including a horizontal flange and a skirt depending downwardly therefrom; and   a first locking projection extending inwardly from said skirt.   
     
     
         2 . The lid of  claim 1 , wherein said cover portion has an upwardly projecting central section. 
     
     
         3 . The lid of  claim 2 , wherein said cover portion is generally dome-shaped. 
     
     
         4 . The lid of  claim 1 , wherein said lid insert rim is releasably retained between said first locking projection and said flange. 
     
     
         5 . The lid of  claim 1 , wherein said ring is configured to be separated from said lid insert upon disposal of said lid. 
     
     
         6 . The lid of  claim 1  further comprising a channel defined between said first locking projection and a bottom surface of said flange. 
     
     
         7 . The lid of  claim 6 , wherein said channel is sized and shaped to receive an outer edge of said lid insert rim. 
     
     
         8 . The lid of  claim 6 , wherein said channel is sized and shaped to receive both an outer edge of said lid insert rim and an outer edge of said base rim. 
     
     
         9 . The lid of  claim 1  further comprising a second locking projection extending inwardly from said skirt, said second locking projection being located beneath said first locking projection. 
     
     
         10 . The lid of  claim 1  further comprising a first channel defined between said first locking projection and a bottom surface of said flange, and a second channel defined between a second locking projection and said first locking projection. 
     
     
         11 . The lid of  claim 10 , wherein said first channel is sized and shaped to receive an outer edge of said lid insert rim and said second channel is sized and shaped to receive an outer edge of said base rim. 
     
     
         12 . The lid of  claim 1 , wherein said lid insert is constructed of a paper-based material and said ring is constructed of a plastic material. 
     
     
         13 . The lid of  claim 1 , wherein said ring is constructed of plastic and is injected molded onto said lid insert rim. 
     
     
         14 . The lid of  claim 1 , wherein said ring is thermoformed and then combined with said lid insert rim. 
     
     
         15 . A container lid adapted to interlock with a container base having a peripheral rim, said lid comprising:
 a lid insert including a central cover portion and a generally flat and horizontal peripheral lid rim extending around at least part of said cover portion;   a ring circumscribing at least part of said lid insert rim, said ring including:
 a generally horizontal and outwardly extending upper flange; 
 an upper skirt extending downwardly from said upper flange; 
 a generally horizontal lower flange extending outwardly from said upper skirt; 
 a lower skirt extending downwardly from said lower flange; 
 a first locking projection extending inwardly from said upper skirt; and 
 one or more second locking projections extending inwardly from said lower skirt. 
   
     
     
         16 . The lid of  claim 15  further comprising a first channel defined between said first locking projection and a bottom surface of said upper flange. 
     
     
         17 . The lid of  claim 16  further comprising a second channel defined between at least one of said second locking projections and a bottom surface of said lower flange. 
     
     
         18 . The lid of  claim 17  further comprising a third channel defined between two said second locking projections. 
     
     
         19 . A method of manufacturing a lid adapted to interlock with a container base having a peripheral rim, said method comprising the steps of:
 forming a paper-based material into a lid insert having a peripheral rim; and   forming an injection molded plastic ring around at least a portion of said lid insert rim, wherein said plastic ring includes a horizontal flange, a skirt depending downwardly from the horizontal flange and a locking projection extending inwardly from said skirt.   
     
     
         20 . A method of manufacturing a lid adapted to interlock with a container base having a peripheral rim, said method comprising the steps of:
 forming a paper-based material into a lid insert having a peripheral rim; and   thermoforming a molded plastic ring that includes a horizontal flange, a skirt depending downwardly from the horizontal flange and a locking projection extending inwardly from said skirt; and   combining said plastic ring and said lid insert.