High-strength, lightweight blow-molded plastic structures

Abstract

Blow-molded plastic structures may include a plurality of depressions and the depressions may have different characteristics depending, for example, upon the particular configuration of the depression. For example, a depression may have an elongated length and it may have increased strength along its length. The depressions may be arranged into a pattern in order to take advantage of particular characteristics of the depressions. For example, the depressions may be arranged to maximize the strength and/or minimize the weight of the structure. The depressions may also be arranged to create a structure with generally uniform characteristics. Significantly, the depressions may be arranged into a number of different patterns depending, for example, upon the intended use of the structure. For instance, the depressions may be arranged into a pattern with one or more rows and columns, and the depressions may be disposed in particular positions or orientations within the rows or columns.

1 . A structure constructed from blow-molded plastic, the structure comprising: 
 a first surface;    a second surface that is spaced apart from the first surface;    a hollow interior portion formed during the blow-molding process;    a plurality of depressions formed in the second surface and extending towards the first surface, each of the plurality of depressions having generally the same general shape, the plurality of depressions comprising: 
 a first depression, a second depression, a third depression and a fourth depression positioned in a generally parallelogram shaped configuration; and  
 a fifth depression positioned proximate a central portion of the generally parallelogram shaped configuration, the fifth depression being orientated at first angle, the first depression being disposed at an angle that is oblique to the first angle, the second depression being disposed at an angle that is oblique to the first angle, the third depression being disposed at an angle that is oblique to the first angle, the fourth depression being disposed at an angle that is oblique to the first angle.  
   
   
   
       2 . The structure constructed from blow-molded plastic as in  claim 1 , wherein the first depression is oriented generally perpendicular to the second depression, the first depression is oriented generally perpendicular to the fourth depression, the second depression is oriented generally perpendicular to the first depression, the second depression is oriented generally perpendicular to the third depression, the third depression is oriented generally perpendicular to the second depression, the third depression is oriented generally perpendicular to the fourth depression, the fourth depression is oriented generally perpendicular to the first depression, and the fourth depression is oriented generally perpendicular to the third depression.  
   
   
       3 . The structure constructed from blow-molded plastic as in  claim 1 , wherein the first depression, the second depression, the third depression and the fourth depression positioned in a generally rectangular shaped configuration.  
   
   
       4 . The structure constructed from blow-molded plastic as in  claim 1 , wherein the first depression, the second depression, the third depression and the fourth depression positioned in a generally square shaped configuration.  
   
   
       5 . The structure constructed from blow-molded plastic as in  claim 1 , wherein the first, second, third, and fourth depressions each include a major axis that intersects a portion of the fifth depression.  
   
   
       6 . The structure constructed from blow-molded plastic as in  claim 1 , wherein the first, second, third, and fourth depressions each include a minor axis that intersects a portion of the fifth depression.  
   
   
       7 . The structure constructed from blow-molded plastic as in  claim 1 , wherein the depressions have a generally oblong configuration.  
   
   
       8 . A structure constructed from blow-molded plastic, the structure comprising: 
 a first surface;    a second surface that is spaced apart from the first surface;    a hollow interior portion that is formed during the blow-molding process;    a plurality of depressions formed in the second surface and extending towards the first surface, each of the plurality of depressions having generally the same shape, the plurality of depressions comprising: 
 a first depression, a second depression, a third depression and a fourth depression positioned in a generally parallelogram shaped configuration, the first depression being disposed proximate the second and fourth depressions, the second depression being disposed proximate the first and third depressions, the third depression being disposed proximate the second and fourth depressions, the fourth depression being disposed proximate the first and third depressions; the first and third depressions being positioned at opposing corners of the generally parallelogram shaped configuration, the second and fourth depressions being positioned at opposing corners of the generally parallelogram shaped configuration; the first and third depressions being oriented generally perpendicular to each other; the second and fourth depressions being oriented generally perpendicular to each other; the third depression being orientated at a first angle, the second depression being orientated at angle that is oblique to the first angle, the fourth depression being orientated at angle that is oblique to the first angle.  
   
   
   
       9 . The structure constructed from blow-molded plastic as in  claim 8 , wherein the second depression is orientated at angle that is between about 35 degrees to about 55 degrees from the first angle, and the fourth depression is orientated at angle that is between about 35 degrees to about 55 degrees from the first angle.  
   
   
       10 . The structure constructed from blow-molded plastic as in  claim 8 , wherein the second depression is orientated at angle that is about 45 degrees from the first angle, and the fourth depression is orientated at angle that is about 45 degrees from the first angle.  
   
   
       11 . The structure constructed from blow-molded plastic as in  claim 8 , wherein the first depression, the second depression, the third depression and the fourth depression positioned in a generally rectangular shaped configuration.  
   
   
       12 . The structure constructed from blow-molded plastic as in  claim 8 , wherein the first depression, the second depression, the third depression and the fourth depression positioned in a generally square shaped configuration.  
   
   
       13 . The structure constructed from blow-molded plastic as in  claim 8 , wherein the depressions have a generally oblong configuration.  
   
   
       14 . A structure constructed from blow-molded plastic, the structure comprising: 
 a first surface;    a second surface that is spaced apart from the first surface;    a hollow interior portion formed during the blow-molding process;    a plurality of depressions formed in the second surface and extending towards the first surface, each of the plurality of depressions having generally the same shape, the plurality of depressions comprising: 
 a first row of depressions, the depressions of the first row alternating between a first orientation and a second orientation, the first and second orientations being generally perpendicular to each other; and  
 a second row of depressions adjacent the first row of depressions, the depressions of the second row alternating between a third orientation and a fourth orientation, the third and fourth orientations being generally perpendicular to each other,  
 the first orientation being at an angle that is oblique to the third and fourth orientations, the second orientation being at an angle that is oblique to the third and fourth orientations, the third orientation being at an angle that is oblique to the first and second orientations, the fourth orientation being at an angle that is oblique to the first and second orientations.  
   
   
   
       15 . The structure constructed from blow-molded plastic as in  claim 15 , wherein the first orientation is between about 35 degrees to about 55 degrees from the third orientation, and the second orientation is between about 35 degrees to about 55 degrees from the third orientation.  
   
   
       16 . The structure constructed from blow-molded plastic as in  claim 15 , wherein the first orientation is about 45 degrees from the third orientation, and the second orientation is about 45 degrees from the third orientation.  
   
   
       17 . The structure constructed from blow-molded plastic as in  claim 15 , wherein the depressions of the second row are offset from the depressions of the first row.  
   
   
       18 . The structure constructed from blow-molded plastic as in  claim 15 , wherein the plurality of depressions further comprises: 
 a third row of depressions adjacent the second row of depressions, the depressions of the third row alternating between the first orientation and the second orientation; and    a fourth row of depressions adjacent the third row of depressions, the depressions of the fourth row alternating between the third orientation and the fourth orientation.