Pressure container with differential vacuum panels

Abstract

A plastic container ( 1 ) has a first set of flex panels ( 2 ) and a second set of flex panels ( 3 ) at least one set being adapted to react to pressure changes within the container to a different degree which can be achieved by different curvature and/or size and/or different distance from a central longitudinal axis of the container. At least one of the panels has at least two different extents of curvature. In some embodiments one or more of the panels may be flat.

1 . A plastic container having a body portion including a sidewall wherein said body portion includes:
 a first controlled deflection flex panel on one sidewall portion, and a second controlled deflection flex panel on a second sidewall portion, at least one of said controlled deflection flex panels having at least two different extents of outward curvature,   said first and second flex panels being adapted to react to pressure changes within the container to a different degree.   
   
   
       2 . The plastic container of  claim 1  wherein the first controlled deflection flex panel has a width which is less than the width of the second controlled deflection flex panel. 
   
   
       3 . The plastic container of  claim 1  wherein the second controlled deflection flex panel has one or a plurality of ribs incorporated within. 
   
   
       4 . The plastic container of  claim 3  wherein at least one, of said sidewall portions is symmetrical to an opposing side wall portion relative to rib and flex panel placement, size and number. 
   
   
       5 . The plastic container of  claim 4  wherein a, cage structure of ribs and flex panels cooperate to maintain container shape upon filling and cooling of the container. 
   
   
       6 . The plastic container of  claim 1  wherein the first and second flex panels are adapted to react to pressure changes to a different degree by being of a different size and/or different distance from a central longitudinal axis of the container and/or having a different curvature. 
   
   
       7 . The plastic container of  claim 1  wherein the container is hot-fillable. 
   
   
       8 . The plastic container of  claim 1  including a base which is rounded. 
   
   
       9 . The plastic container of  claim 1  including a base which is non-rounded. 
   
   
       10 . The plastic container of  claim 1  or  2 , wherein there is a pair of opposite first controlled deflection flex panels and an adjacent pair of opposite second controlled deflection flex panels. 
   
   
       11 . The plastic container of  claim 1  wherein the first controlled deflection flex panel has one or a plurality of ribs incorporated within. 
   
   
       12 . The plastic container of  claim 3  or  11  wherein the said ribs include either an outward or inwardly facing rounded edge, relative to the interior of the container. 
   
   
       13 . The plastic container of  claim 12  wherein said ribs are parallel to each other. 
   
   
       14 . The plastic container of  claim 1  wherein the first controlled deflection flex panel has a region of generally outward transverse curvature. 
   
   
       15 . The plastic container of  claim 1  wherein the second controlled deflection flex panel has a region of generally outward transverse curvature. 
   
   
       16 . The plastic container of  claim 1  wherein the first controlled deflection flex panel inverts under vacuum pressure. 
   
   
       17 . A container for accommodating volume contraction within the container after being filled with a heated liquid, having a sidewall portion including four flex panels spaced apart around the circumference of a body portion, and arranged as a first pair of of opposed panels and a second pair of opposed panels, at least one of said flex panels having at least two different extents of curvature wherein the panels can deform inwardly to accommodate vacuum pressure caused by volume contraction of the heated liquid and wherein the panels are formed so the first pair of panels deforms inwardly at a different rate than the second pair of panels. 
   
   
       18 . The container of  claim 17  wherein one said pair of panels has a different amount of outward curvature to the other said pair of panels. 
   
   
       19 . The container of  claim 17  wherein one said pair of panels is substantially flat. 
   
   
       20 . The container of  claim 17  wherein one said pair of panels is substantially concave. 
   
   
       21 . The container of  claim 17  wherein one said pair of panels has a variable outward curvature. 
   
   
       22 . The container of  claim 17  wherein one said pair of panels has a generally even outward radius of curvature, excluding any ribs or grip features on said panels. 
   
   
       23 . The container of  claim 22  wherein one said pair of panels has a variable outward projection. 
   
   
       24 . The container of  claim 23  wherein a substantially central section of said panels projects outward to a greater extent. 
   
   
       25 . The container of  claim 23  wherein a substantially central section of said panels projects outward to a lesser extent. 
   
   
       26 . (canceled) 
   
   
       27 . The container of either of  claim 1  or  claim 17  wherein said at least two different extents of curvature comprise varying amounts of projection from a plane defined by a longitudinal axis of said at least one panel. 
   
   
       28 . The container of  claim 27  wherein a substantially constant arc of curvature is provided along said longitudinal axis of said at least one panel. 
   
   
       29 . The container of  claim 27  wherein a variable arc of curvature is provided along said longitudinal axis of said at least one panel.