Paper drink cup lid with stacking and sealing features

Abstract

A lid formed from a single piece of paper material for use with a container. The container has an annular rim. The lid includes a center portion and a nesting lug joined to the center portion. The nesting lug defines a receiving cavity sized to closely correspond to a curved outer surface of the annular rim. The lid further includes a support shoulder extending from the nesting lug and a skirt. The skirt includes an outer wall and an inner wall joined to each other at a fold. A skirt locking tab extends from the inner wall into the receiving cavity of the nesting lug. When the lid is installed on the container, the receiving cavity of the nesting lug contacts the outer surface of the annular rim to create a seal and the locking skirt tab engages the annular rim to hold the annular rim in the receiving cavity.

We claim: 
     
         1 . A lid formed from a single piece of paper material and configured for use with a container having a container sidewall and an annular rim extending around an open upper end of the container, the annular rim including a curved outer surface, the lid comprising:
 a planar center portion having a diameter less than the diameter of the annular rim;   a nesting lug joined to the center portion and extending above the center portion, the nesting lug defining a receiving cavity sized to closely correspond to curved outer surface of the annular rim;   a support shoulder extending radially outward from the nesting lug;   a skirt extending from the support shoulder, the skirt including an outer wall and an inner wall joined to each other; and   a locking skirt tab extending from an end of the inner wall and into the receiving cavity of the nesting lug from the inner wall,   wherein when the lid is installed on the container, the receiving cavity of the nesting lug is in contact with the outer surface of the annular rim to create a seal therebetween and the locking skirt tab engages the annular rim below an equator of the annular rim to hold the annular rim in the receiving cavity.   
     
     
         2 . The lid of  claim 1  wherein the skirt extends from the support shoulder perpendicular to the center portion. 
     
     
         3 . The lid of  claim 1  wherein the outer wall and the inner wall of the skirt are connected to each other at a fold. 
     
     
         4 . The lid of  claim 1  wherein the support shoulder is annular and sized to receive the skirt of another lid in a stacked configuration. 
     
     
         5 . The lid of  claim 1  wherein the outer wall and the inner wall are joined to each other by an adhesive and the locking skirt tab extends at a locking angle from the end of the inner wall. 
     
     
         6 . The lid of  claim 1  wherein the receiving cavity of the nesting lug is in contact with the outer surface of the annular rim over at least 90°. 
     
     
         7 . The lid of  claim 1  wherein the locking skirt tab guides the annular rim into the receiving cavity when the lid is installed on the container. 
     
     
         8 . A container comprising:
 a container sidewall formed from a paper material;   an annular rim extending around an open upper end of the container sidewall, the annular rim including an outer surface,   a lid formed from a single piece of paper material, the lid comprising:
 a planar center portion having a diameter less than the diameter of the annular rim; 
 a nesting lug joined to the center portion and extending above the center portion, the nesting lug defining a receiving cavity sized to closely correspond to the annular rim; 
 a support shoulder extending radially outward from the nesting lug; 
 a skirt extending from the support shoulder, the skirt including an outer wall and an inner wall joined to each other; and 
 a locking skirt tab extending into the receiving cavity of the nesting lug from the inner wall, 
   wherein when the lid is installed on the container, the receiving cavity of the nesting lug is in contact with the outer surface of the annular rim to create a seal therebetween and the locking skirt tab engages the annular rim below an equator of the annular rim.   
     
     
         9 . The container of  claim 8  wherein the skirt extends from the support shoulder perpendicular to the center portion. 
     
     
         10 . The container of  claim 8  wherein the locking skirt tab holds the lid on the annular rim of the container. 
     
     
         11 . The container of  claim 8  wherein the outer wall and the inner wall of the skirt are connected to each other at a fold. 
     
     
         12 . The container of  claim 8  wherein the support shoulder is annular and sized to receive the skirt of another lid in a stacked configuration. 
     
     
         13 . The container of  claim 8  wherein the outer wall and the inner wall are joined to each other by an adhesive and the locking skirt tab extends at a locking angle from the inner wall. 
     
     
         14 . The container of  claim 8  wherein the receiving cavity of the nesting lug is in contact with the outer surface of the annular rim over at least 90°.