Container having internal strengthening ribs

Abstract

A container includes internal strengthening ribs which increase the compressive strength of the container. The ribs have a rounded surface to facilitate manufacturing. In a preferred embodiment, the ribs are disposed on the inside surface of the container in spaced apart relationship.

I claim:  
     
         1 . A polymer container, comprising: 
 a hollow body having a top, an opposite bottom, a wall having a thickness and an inside surface, and a longitudinal axis passing though said top and said bottom;    at least one rib having a rounded surface disposed on said inside surface; and,    said rib increasing the compressive strength of said container.    
     
     
         2 . A container according to  claim 1 , further including: 
 said rib and said inside surface forming first and second longitudinal concave junctions; and,    when viewed in cross section, said junctions being rounded.    
     
     
         3 . A container according to  claim 1 , further including: 
 said rib having a height; and,    said height being between about 0.75 and 1.25 times said wall thickness.    
     
     
         4 . A container according to  claim 1 , further including: 
 said rib having a height; and,    said height being between about 0.020 inches and 0.040 inches.    
     
     
         5 . A container according to  claim 1 , further including: 
 said rib having a height and a width; and,    a ratio of said width to said height being between about 4 and 8 to one.    
     
     
         6 . A container according to  claim 1 , further including: 
 a plurality of said ribs disposed on said inside surface.    
     
     
         7 . A container according to  claim 1 , further including: 
 said rib being closed and extending around said inside surface substantially perpendicular to said longitudinal axis.    
     
     
         8 . A container according to  claim 7 , further including: 
 a plurality of said closed ribs residing in parallel spaced apart relationship around said inside surface.    
     
     
         9 . A container according to  claim 1 , further including: 
 said rib disposed substantially parallel to said longitudinal axis.    
     
     
         10 . A container according to  claim 9 , further including: 
 a plurality of said ribs residing in parallel spaced apart relationship.    
     
     
         11 . A container according to  claim 1 , further including: 
 said rib forming an acute angle with a projection of said longitudinal axis upon said inside surface.    
     
     
         12 . A container according to  claim 11 , further including: 
 a plurality of parallel spaced apart said ribs each of which forms an acute angle with said projection of said longitudinal axis upon said inside surface.    
     
     
         13 . A container according to  claim 12 , further including: 
 a second plurality of parallel spaced apart said ribs each of which forms and opposite acute angle with said projection of said longitudinal axis upon said inside surface; and,    said plurality and said second plurality of spaced apart ribs creating a diamond shaped pattern.    
     
     
         14 . A container according to  claim 1 , further including; 
 said rib comprising a truss which forms a ridged framework for supporting said wall.    
     
     
         15 . A container according to  claim 1 , further including: 
 said rib and said inside surface forming first and second longitudinal concave junctions;    when viewed in cross section, said junctions being rounded;    said rib having a height, said height being between about 0.75 and 1.25 times said wall thickness;    said rib comprising a truss which forms a ridged framework for supporting said wall;    a plurality of said ribs disposed on said inside surface; and,    said plurality residing in parallel spaced apart relationship.