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.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority to, and the benefit of, U.S. provisional patent application Ser. No. 60 / 659,982, filed Mar. 9, 2005, which is incorporated by reference.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention generally relates to structures constructed from blow-molded plastic and, in particular, to high-strength, lightweight blow-molded plastic structures. [0004] 2. Description of Related Art [0005] It is known to construct various objects and items, such as tables, chairs, partitions, walls, and sports equipment, from plastic. It is also known to construct some of these and other objects from blow-molded plastic. As known to those skilled in the art, blow-molded structures often include an outer wall that encloses a hollow interior space. Because blow-molded structures include a hollow interior space, many blow-molded structures are not high-strength. In fact, many known blow-molded st...

AI Technical Summary

Benefits of technology

[0011] A need therefore exists for structures constructed from blow-molded plastic that eliminates or reduces some or all of the above-described disadvantages and problems.

[0012] One aspect is a structure that can be constructed from blow-molded plastic and have increased strength. Preferably the blow-molded plastic structure has both increased strength and it is lightweight, but the structure does not have to be lightweight and high-strength.

Problems solved by technology

Because blow-molded structures include a hollow interior space, many blow-molded structures are not high-strength.

In fact, many known blow-molded structures are relatively low-strength and are unable to support a relatively large amount of weight or force.

Disadvantageously, the metal ribs must be attached to the table top by mechanical fasteners such as bolts or screws.

The bolts or screws require holes in the table top, which may create stress concentrations and / or potential failure points in the table top.

Alternatively, the metal ribs may be attached to the table top by adhesives, but the adhesives may also decrease the structural integrity of the table top and make the table top very difficult to repair or replace.

In addition, the metal ribs may increase the number of components required to construct the table and the time required to manufacture the table.

Thus, while it is known to use metal ribs to increase the strength of a blow-molded table top, the metal ribs may undesirably increase the time and costs to manufacture the table.

Further, the attachment of the metal ribs to the table top may decrease the strength and / or structural integrity of the table top, and increase the potential causes of failure of the table.

Disadvantageously, the thicker outer walls of the ribs may require additional plastic materials be used to create the table top, which may undesirably increase the costs and weight of the table tops.

In addition, the thicker outer walls may retain more heat during the manufacturing process.

This may undesirably increase the time of the manufacturing process because the blow-molded table tops cannot be removed from the mold until the tops are sufficiently cooled.

Disadvantageously, the large, protruding ribs may undesirably decrease the amount of room underneath the table top, decrease the usefulness of the table and limit potential design considerations and / or arrangements of the table top.

Conventional table tops that are constructed from blow-molded plastic and include strengthening ribs, however, may still not have sufficient strength and may allow a portion of the table top to sag.

These additional ribs undesirably require a larger area on the underside of the table top, which may limit the area that other features may be formed in the table top.

The numerous strengthening ribs may also interfere with other features or components of the table, such as interfering with the folding of the table legs into a collapsed position.

Thus, the upper surface of the table top may be uneven because different portions of the table top are supported differently.

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