Combined lip and shoulder seal for threaded cap

Abstract

An improved cap is provided for sealing an opening formed in an associated bottle. The cap is preferably internally threaded for receipt over a threaded portion of the bottle. A flap extends from a planar surface of the cap and is directed for receipt in the associated bottle opening. A shoulder also extends outwardly from the planar surface and is spaced inwardly from the flap to engage the seal flap as the cap is threaded onto the bottle. The cap is preferably formed of a rigid plastic such as high density polyethylene (HDPE).

1 . A cap for selectively sealing an opening formed in an associated bottle that includes an external thread portion around the opening, the cap comprising:
 a generally planar surface dimensioned to overlie the associated bottle opening;   a sidewall extending from the planar surface including internal thread portions thereon dimensioned for cooperative threaded engagement with the associated bottle thread portion;   a lip extending from one of the planar surface and the sidewall and directed inwardly from the sidewall for receipt in the associated bottle opening; and   a shoulder extending outwardly from the planar surface and spaced inwardly from the lip for engaging the seal lip as the cap is threaded on to the associated bottle.   
     
     
         2 . The cap of  claim 1  wherein the lip has a variable thickness along a length thereof. 
     
     
         3 . The cap of  claim 2  wherein the lip has a thicker cross-sectional dimension adjacent an interconnecting region with one of the planar surface and the sidewall. 
     
     
         4 . The cap of  claim 1  wherein the lip has a thicker cross-sectional dimension adjacent an interconnecting region with one of the generally planar surface and the sidewall. 
     
     
         5 . The cap of  claim 1  wherein the cap is formed of a rigid plastic such as HDPE. 
     
     
         6 . The cap of  claim 1  wherein the lip extends from the generally planar surface and is spaced radially inward from the sidewall. 
     
     
         7 . The cap of  claim 6  wherein the shoulder is spaced radially inward of the lip. 
     
     
         8 . The cap of  claim 7  wherein the shoulder extends outwardly from the generally planar surface a dimension less than the lip extends outwardly from the generally planar surface. 
     
     
         9 . The cap of  claim 1  wherein the shoulder extends outwardly from the generally planar surface a dimension less than the lip extends outwardly from the generally planar surface. 
     
     
         10 . The cap of  claim 1  wherein the shoulder is spaced radially inward of the lip. 
     
     
         11 . The cap of  claim 1  further comprising a stop surface on the cap that is located to operatively engage a corresponding stop shoulder on the associated bottle to limit forces imposed on the lip and shoulder. 
     
     
         12 . A molded plastic cap for a fluid bottle having an opening, the molded plastic cap comprising:
 a generally planar member dimensioned for covering receipt over the bottle opening;   a sidewall extending outwardly in a first direction from adjacent a perimeter of the generally planar member and surrounding the opening;   a contoured lip extending a first dimension from an interior surface of the generally planar member and inwardly from adjacent a perimeter thereof; and   a shoulder extending a second dimension from the interior surface of the generally planar member and spaced further inwardly from the perimeter than the lip for sealingly engaging the lip to the associated bottle.   
     
     
         13 . The cap of  claim 12  wherein the lip has a reduced thickness at a distal end relative to a proximal end. 
     
     
         14 . The cap of  claim 12  wherein the cap is formed of a rigid HDPE material. 
     
     
         15 . The cap of  claim 12  wherein the lip first dimension is greater than the shoulder second dimension. 
     
     
         16 . The cap of  claim 12  wherein the sidewall includes a thread portion along an inner surface thereof for cooperative threaded engagement with an external thread portion around the opening of the associated bottle. 
     
     
         17 . The cap of  claim 12  further comprising a stop surface for limiting advancement of the cap onto the bottle over the opening. 
     
     
         18 . The cap of  claim 12  further comprising a pour opening in the generally planar member and a closure lid hinged thereto. 
     
     
         19 . The cap of  claim 18  wherein the pour opening includes a thin walled tamper evident member integrally molded with the generally planar member.