Self-Standing Container

Abstract

A petaloid base for a self-standing container has an approximately hemispherical underlying base contour and a plurality of ovoid foot formations that interrupt and project from the underlying base contour to define a corresponding plurality of feet. Its shape resists stress cracking, maximises capacity relative to the height of the container and reduces the surface area of the base and hence material usage in comparison with equivalent known designs.

1 . A petaloid base for a self-standing container, the base having a spheroidal underlying base contour and a plurality of spheroidal foot formations that interrupt and project from the underlying base contour to define a corresponding plurality of feet. 
     
     
         2 . The base of  claim 1 , wherein the underlying base contour is an oblate spheroid whose polar axis coincides with a central axis of the base. 
     
     
         3 . The base of  claim 1 , wherein the underlying base contour is substantially hemispherical. 
     
     
         4 . The base of  claim 1 , wherein the foot formations are elongate ellipsoids. 
     
     
         5 . The base of  claim 4 , wherein the foot formations are prolate spheroids. 
     
     
         6 . The base of  claim 4 , wherein the foot formations are ovoid, and wherein the widest part of the cross-section of each foot formation is offset inwardly toward an inner end of the foot formation. 
     
     
         7 . (canceled) 
     
     
         8 . The base of  claim 4 , wherein the foot formations have respective longitudinal axes, which axes lie in planes extending radially from a central axis of the base. 
     
     
         9 . The base of  claim 8 , wherein the axes of the foot formations extend outwardly in conical relation from the central axis of the base. 
     
     
         10 . The base of  claim 9 , wherein the axes of the foot formations extend outwardly and upwardly from the central axis of the base, and wherein the axes of the foot formations meet at the central axis of the base at a position axially below the base. 
     
     
         11 . (canceled) 
     
     
         12 . The base of  claim 1 , wherein each foot formation has an elliptical intersection with the underlying base contour, the intersection is ovate and of concave cross section. 
     
     
         13 - 14 . (canceled) 
     
     
         15 . The base of  claim 1 , wherein the foot formations radiate from a central protrusion. 
     
     
         16 . The base of  claim 15 , wherein the central protrusion has a radius of curvature that is smaller than the radius of curvature of the underlying base curve, and wherein the central protrusion extends to a level beyond the lowermost apex of the underlying base contour. 
     
     
         17 . (canceled) 
     
     
         18 . The base of  claim 15 , wherein a foot formation and the central protrusion are joined via a smoothly curving transition portion,
 wherein the foot formation, the smoothly curving transition portion and the central protrusion together define a sinuous cross section, and wherein the transition portion defines a curve whose curvature is converse to the curvature of at least one of the foot formations and central protrusion.   
     
     
         19 - 20 . (canceled) 
     
     
         21 . The base of  claim 15 , wherein the central protrusion is substantially convex with respect to the exterior of the container. 
     
     
         22 . The base of  claim 15 , wherein the central protrusion defines a recess with respect to the interior of the container, the recess being arranged to locate and retain a free end of a fluid delivery tube within the container. 
     
     
         23 . The base of  claim 15 , wherein the central protrusion is generally polygonal, with a number of sides corresponding to the number of foot formations,
 wherein the foot formations are separated by valleys, and   the valleys radiate from apices of the polygonal protrusion.   
     
     
         24 . The base of  claim 1 . 
     
     
         25 . The base of  claim 15 . 
     
     
         26 . The base of  claim 1 , wherein the foot formations are separated by valleys, the valleys widen moving outwardly across the base, each valley has an inner and an outer section and the walls of the valley diverge more sharply in the outer section than in the inner section, and the walls of the valley diverge in both the inner and the outer sections of the valley. 
     
     
         27 - 28 . (canceled) 
     
     
         29 . The base of  claim 1 , wherein in plan view, each foot formation has an enlarged central region that tapers inwardly across an inner portion to an inner end of the foot formation, the inner portions of the foot formations lie in segmented relation around the base, and each foot formation tapers from the enlarged central region outwardly across an outer portion to an outer end of the foot formation. 
     
     
         30 - 31 . (canceled) 
     
     
         32 . A self-standing container having a base as defined in  claim 1 . 
     
     
         33 . The container of  claim 32 , wherein the foot formations of the base define respective contact points that together are spaced around a contact circle whose diameter (x) relates to a side wall diameter (Dy) of the container as: 
       
         
           
             
               
                 Dy 
                 
                   0.5 
                    
                   x 
                 
               
               = 
               k 
             
           
         
       
       where k is between 3.6 and 5.5. 
     
     
         34 . The container of  claim 33 , wherein k is between 4.0 and 5.3. 
     
     
         35 . The container of  claim 34 , wherein k is between 4.2 and 5.0. 
     
     
         36 . The container of  claim 32 , having an average burst pressure resistance to material usage ratio of greater than 3 MPa/kg. 
     
     
         37 . The container of  claim 32 , having a capacity to material usage ratio of greater than 40 litres/kg. 
     
     
         38 . The container of  claim 32 , comprising a fluid delivery tube aligned with a central longitudinal axis of the container, the tube extending between the base of the container and an opening of the container.