BACKGROUND
It is well known to place an air bag in all types of footwear to provide cushioning against impact of the footwear on the ground. While air bags do provide cushioning, they can become compromised such that the air escapes the air bag, which makes the air bag ineffective. This leaking can either be slowly due to a small amount of air leaking each time the foot bag impacts the ground, or very quickly when a nail, or other sharp object, penetrates the air bag. This latter event is particularly a problem with work boots.
SUMMARY OF THE INVENTION
A cushioning system for footwear comprises a matrix of hollow elastomeric tubes joined together to create a honeycomb which is placed in footwear between the sole and upper. The tube matrix may or may not be enclosed within an air bag.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is fragmentary portion of a boot, partially broken away to show the subject invention.
FIGS. 2A and 2B are cross-sectional views taken along the line 2-2 of FIG. 1, showing alternate embodiments of the subject invention.
FIGS. 3-6 are side elevational views, similar to FIG. 1 showing different embodiments of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to FIG. 1 of the drawings, a boot, or other type of footwear, 10 has a cushioning system 12 located between its outsole 14 and upper 16, in a location where air bags typically are located. The cushioning system is a plurality of elongate, hollow, elastomeric tubes 18 which preferably are attached to one another to create an integral assembly in the nature of a honeycomb matrix. The tubes can be made from any elastomeric material, and different materials will provide different cushioning characteristics. Materials that would work well for this purpose are thermoplastic olefins or thermoplastic elastomers. The honeycomb typically would be made by injecting molding.
The size of the tubes 18 and their wall thickness, or both, can vary depending on where they were placed in the footwear and the desired level of cushioning. For example, the tubes located in the toe section of the boot illustrated in FIG. 1 are smaller than the tubes located in the heel section, and have a smaller wall thickness. While the drawing shows a specific uniform tube size and thickness in the toe section and a specific uniform tube size and thickness in the heel section, there could be multiple size tubes in the toe section or the heel section. In addition, the cushioning system may only be in the toe, FIG. 3, only be in the heel, FIG. 4, or extend over the entire extent of the boot, FIG. 5.
The tubes can be polygonal in a cross-section, such as the hexagonal tubes shown in FIGS. 1 and 3-5, or circular in cross-section, as shown in FIG. 6. The tubes may or may not be enclosed within an air bag 20, FIG. 2B. The air in the air bag can either be at or around ambient pressure or at an elevated pressure. When the tubes are enclosed in an air bag, the tubes provide some of the cushioning effect and the air bag produces some of the cushioning effect. However, unlike a boot with cushioning provided only by an air bag, if the air bag is punctured the tubes still provide some cushioning.
The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow.