Multi-functional base for a plastic, wide-mouth, blow-molded container

Abstract

A blow molded container having a multi-functional base which enables use of the container in both hot-fill operations and pasteurization/retort operations and enables efficient vertical stacking of like containers. To this end, a portion of the base is capable of flexing upwardly and/or downwardly in response to variations in pressures in a filled and sealed container. Structurally, the base has a continuous or discontinuous concave outer annular wall forming a continuous or discontinuous standing ring and an inner annular wall functioning as a flex panel. The inner annular wall connects outwardly to a plurality of radial webs extending at an elevation above the standing ring and connects inwardly to a central dimple. Preferably, the inner periphery of the annular wall is heat-set and biaxially oriented.

1 . A container comprising a blow molded plastic body having an integrally formed base with a central annular wall having an inner periphery connecting to an anti-inverting central dimple that projects from said inner periphery of said inner annular wall, said inner periphery being made of blow molded plastic material that is heat-set and biaxially-oriented, said inner annular wall of said base flexing upwardly and downwardly in response to variations in pressures within the container, when capped and filled, without undergoing unwanted permanent deformation.  
     
     
         2 . A container according to  claim 1 , wherein said central dimple includes an indented, substantially-circular surface having indented hollow ribs formed therein.  
     
     
         3 . A container according to  claim 1 , further comprising a plurality of spaced-apart, radially-extending, indented ribs on said base where said inner periphery of said central annular wall interconnects to said central dimple.  
     
     
         4 . A container according to  claim 3 , wherein said base has a concave outer annular wall with an outer portion and an inner portion forming a container standing surface therebetween.  
     
     
         5 . A container according to  claim 4 , wherein said concave outer annular wall is continuous.  
     
     
         6 . A container according to  claim 4 , wherein said concave outer annular wall is discontinuous.  
     
     
         7 . A container according to  claim 4 , wherein said inner portion of said outer annular wall has a support ridge formed therein above a level of said container standing surface to facilitate vertical stacking of containers having like bases.  
     
     
         8 . A container according to  claim 4 , wherein said standing ring has a diameter of at least about 3.7 inches, and said inner periphery of said central annular wall is less than about 1.25 inches.  
     
     
         9 . A blow-molded plastic container comprising an integrally formed base made of blow molded plastic material, said base having: 
 a discontinuous concave outer annular wall having an outer portion and an inner portion forming a standing ring therebetween;    an inner annular wall extending inwardly from said inner portion of said outer annular wall, said inner annular wall having an inner periphery and an outer periphery, said outer periphery having a plurality of radial webs extending outwardly at an elevation above said standing ring, and said inner periphery being made of blow molded plastic material that is heat-set and biaxially-oriented; and    an anti-inverting central dimple projecting upwardly from said inner periphery of said inner annular wall;    said inner annular wall being deflectable upwardly and downwardly in response to variations in pressures within the container, when capped and filled, without undergoing unwanted permanent deformation below the level of the standing ring.    
     
     
         10 . A container according to  claim 9 , further comprising a plurality of spaced-apart, radially-extending, indented ribs on said base where said inner periphery of said inner annular wall interconnects to said central dimple.  
     
     
         11 . A container according to  claim 9 , wherein said central dimple has a plurality of spaced-apart, radially-extending, indented ribs formed therein.  
     
     
         12 . A container according to  claim 9 , further comprising a shoulder extending radially inward on said inner portion of said outer annular wall above a level of said standing ring to facilitate vertical stacking of containers having like bases.  
     
     
         13 . A container according to  claim 9 , further comprising a thin-walled body extending upwardly from said outer annular wall and having a blown wide-mouth threaded finish at an upper end of said body.  
     
     
         14 . A container according to  claim 9 , wherein said container and base is made of PET, wherein said standing ring has a diameter of at least about 3.7 inches, and said inner periphery of said inner annular wall is less than about 1.25 inches and said outer periphery of said inner annular wall is at least about 2.5 inches.  
     
     
         15 . A container, comprising: 
 a blow molded plastic body having a circular base, a cylindrical sidewall projecting from said base, and a threaded finish opposite said base;    said base having a discontinuous concave outer annular wall with an outer portion and an inner portion forming a container standing surface therebetween, said outer portion connecting to said sidewall;    said base having an inner annular wall extending inwardly from said inner portion of said outer annular wall, said inner annular wall having an inner periphery and an outer. periphery, said outer periphery connecting to a plurality of radial webs which extend at an elevation above said container standing surface and which connect to said sidewall, and said inner periphery being made of blow molded plastic material that is heat-set and biaxially-oriented;    said base having an anti-inverting central dimple projecting upwardly from said inner periphery of said inner annular wall; and    said inner annular wall of said base flexing upwardly and downwardly in response to variations in pressures in the container without undergoing unwanted permanent deformation.    
     
     
         16 . A container according to  claim 15 , further comprising a plurality of spaced-apart, radially-extending, indented ribs on said base where said inner periphery of said inner annular wall interconnects to said central dimple.  
     
     
         17 . A container according to  claim 16 , wherein said inner portion of said outer annular wall has a support ridge formed therein above a level of said container standing surface to facilitate vertical stacking of containers having like bases.  
     
     
         18 . A container according to  claim 17 , further comprising a cap for sealing said finish, said cap having a top surface with an outer edge and said outer edge of said cap being engagable with said support ridge formed on a container having a like base to facilitate vertical stacking.  
     
     
         19 . A container according to  claim 17 , wherein said cylindrical sidewall provides a cylindrical label panel having a plurality of longitudinally spaced circumferential reinforcement grooves and outlined by an upper and lower label bumper.  
     
     
         20 . A container according to  claim 17 , wherein said body is made of PET, said discontinuous outer annular wall of said base forms four identical, equally spaced apart, arcuate supports, and said arcuate extent of each arcuate support is greater than an arcuate extent of each radial web.