Footwear with air circulation system

A shoe with an air circulation system has a porous ventilated upper and a compressible pumping chamber in the heel which pumps cooling ambient air from an external air intake into a three dimensional mesh air distribution pad and out through the porous ventilated upper, providing cooling and reducing moisture in the cavity containing the wearer's foot.

FIELD OF THE INVENTION

The present invention relates to the field of shoe and footwear constructions.

BACKGROUND OF THE INVENTION

Modern footwear is available in a myriad of materials and fabrications. Despite great advances in support, there has been relatively little development in thermal management of footwear. The foot generates heat while walking, running, or even at rest. As heat is generated by the foot, the shoe temperature begins to rise, and the foot begins to perspire. Excessive perspiration around the foot leads to foot and shoe odor among other problems.

Specifically, the heat and perspiration released by the foot causes several problems. A wet and warm shoe interior is uncomfortable for the user to wear. Further, the perspiration released by the foot contains sodium chloride and urea, which can stain or discolor the outer surface of the shoe, degrading the expressive value of the shoe to the wearer. Moreover, the perspiration and heat around the foot creates an ideal environment for fungi and bacteria to thrive. Fungi and bacteria consume dead skin cells, and produce waste that is the source of foot odor. Fungi and bacteria convert the amino acid methionine to methanethiol which has a sulfuric smell. As physical activity increases, foot perspiration, bacterial growth, and bacterial waste production all increase, causing odor to intensify. Finally, a warm and moist shoe provides an ideal environment for foot disease, such as Athlete's foot, to thrive.

One approach minimizing the problems stated above is to provide shoe ventilation to transfer heat and moisture away from the foot. The theory behind shoe ventilation is to reduce the interior temperature and humidity of the shoe by transferring heat and foot perspiration generated by the foot away from the interior of the shoe. Since perspiration decreases with decreasing temperature, a decrease in the interior temperature of the shoe decreases the rate of perspiration around the foot. Thus, the goal of shoe ventilation is to maintain an interior shoe temperature as close to the ambient air temperature as possible. By forcing ambient air around the foot and into the shoe cavity, heat and moisture generated by the foot is transferred away from the foot by the circulating air.

Systems have been proposed in the prior art for ventilating the area under the foot. These systems have been directed at systems in the sole of the shoe actuated by foot movement during walking or running to circulate air within the interior of the shoe. While these systems help transfer excess heat away from the bottom of the foot surface they are ineffective because they do not transfer heat away from the top, rear, and sides of the foot. This allows excessive heat and moisture to build up inside the shoe. It is possible to make a shoe upper out of mesh or another relatively breathable material, however, these constructions are only suitable for certain types of running shoes or water shoes, and are not appropriate for street shoe constructions or office wear.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a shoe with an air circulation system which cools the foot by incorporating an air circulation system for transferring heat from the interior of the shoe to the ambient atmosphere.

These and other objects of the present are invention are achieved in one embodiment by a shoe with an air circulation system has a porous ventilated upper and a compressible pumping chamber in the heel which pumps cooling ambient air from an external air intake into a three dimensional mesh air distribution pad and out through the porous ventilated upper, providing cooling and reducing moisture in the cavity containing the wearer's foot.

The invention and its particular features and advantages will become more apparent from the following detailed description considered with reference to the accompanying drawings.

DETAILED DESCRIPTION OF THE DRAWINGS

The disclosures of our prior U.S. Pat. Nos. 7,793,426 and 8,127,465 are hereby incorporated by reference. Also, we hereby incorporate by reference the disclosures of U.S. Pat. Nos. 5,893,219; and 5,826,349.

Referring toFIGS. 1-10, a shoe10with an air circulation system in accordance with the present invention is shown. The shoe with an air circulation system10includes an upper20and a sole40. The upper20and the sole40are positioned together to form the shoe10with an air circulation system. The sole40and the upper20operate together to provide a ventilation system that circulates ambient air through the sole40and upper20, cooling the interior cavity12of the shoe10.

Referring toFIGS. 1 and 9, the upper20includes an outer layer22, a porous middle layer24, and an inner layer26. The inner layer26is adjacent to the interior cavity12of the shoe10. The outer layer22is adjacent to the ambient atmosphere14. The outer layer22, porous middle layer24, and inner layer26are positioned together to form a shoe upper20. The layers22,24,26may be positioned together by any means known in the art, including stitching or gluing with an adhesive. It should be understood that the upper20may include a greater or lesser number of layers, and may include additional components, for example shoe laces.

Preferably the outer layer22is constructed from leather. However, the outer layer22may be constructed from canvas, synthetic leather, EVA, denim, wool, felt, or any other material or combination of materials known in the art. The porous middle layer24is constructed from a porous material through which air can pass with little or no resistance. Preferably the porous middle layer24is constructed from a synthetic mesh fabric material. However, the porous middle layer24may be constructed from any material or combination of materials through which air can pass with little or no resistance. Preferably the inner layer26is constructed from a soft lining.

The inner layer26is preferably provided with a plurality of perforations28to provide a fluid communication between the interior cavity12of shoe10and the porous middle layer24for venting the inside of the upper10to the middle layer24. A uniformly applied plurality of small pinpoint perforations is preferable, however, any appropriate number and size of perforations28can be used.

The outer layer22is provided with one or more vent openings30for venting air out of the porous middle layer24to the atmosphere14outside of the upper20. Desirably, vent openings30are in the form of a plastic eyelet having desirable design or appearance features. The upper may optionally include typical fastenings such as shoe lace holes32and shoe laces, or hook and loop fasteners, or buckles, or an elastic element.

In the embodiments shown inFIGS. 1 and 9, the upper20is positioned on the sole40. Preferably the upper20is affixed to the sole40. In the embodiment shown inFIGS. 1 and 9, the upper20is stitched directly to the sole40. It is preferable that the upper20is attached directly to the sole40using a stitch. However, the upper20may be affixed to the sole40by an adhesive, fastener, or any other means known in the art.

Referring toFIGS. 1-10, the sole40includes an outsole42, a midsole44, and an insole46. Preferably a thermoplastic shank48is provided in the center area of the shoe between the midsole44and insole46.

The air circulation system includes a compressible pumping chamber50located in a heel area52of the shoe between the insole46and the midsole44. Pumping chamber50is a sealed chamber made from a resilient material. Desirably, the heel area52has a downwardly extending bump or bulge53which is comprised of a thin outsole43and thin, deformable portion54of the midsole44, so that the pumping chamber50is periodically compressed by pressure applied thereto by a wearer walking in the shoe10. This periodic compression pumps air through the air circulation system of shoe10. The thin deformable midsole portion54is desirably formed as a series of concentric ribs or rings as best illustrated inFIG. 5, or it may be formed as another ribbed or perforated section to enhance the deformation of the portion54and the pumping of chamber50.

Air is drawn into the air circulation system through an external air intake port60(which may include multiple port openings). An inlet fluid passageway62connects the external air intake port60to the pumping chamber50. Preferably, the external air intake port60is located at a level above a level of the pumping chamber50and the inlet fluid passageway62includes an upwardly extending snorkel64as seen inFIG. 10. Snorkel64is preferably positioned at a rear end11of the shoe10, however, in alternative embodiments, one or more snorkels and/or intake ports may be located on the sides of the shoe or at the front of the shoe.

One or more outlet fluid passageways66connect the pumping chamber50with an air distribution pad70. Air distribution pad70is a three dimensional spacer mesh fabric and is located in a cavity71in the insole46in a forefoot area of the shoe. The upper surface of air distribution pad70is flush with the upper surface of insole46. The three dimensional spacer mesh air distribution pad is preferably formed of a polyester material and provides both comfort underfoot and a breathable material that distributes circulated air under the wearer's foot. Examples of three dimensional spacer mesh fabrics that may be used in the invention include fabrics such as those disclosed in U.S. Pat. Nos. 5,385,036; 6,477,865; 6,630,414; 6,755,052; and 7,788,952, the disclosures of which are hereby incorporated by reference. The spacer mesh fabric should have a compression set which is generally comparable to the compression set of the foam material used in the insole46, and should have a sufficient durability to maintain usability over the expected life of the shoe without a significant deviation in thickness compared to the surrounding insole46.

In order to provide the desired pumping of air through the air circulation system, an inlet check valve80is located in the midsole44between the external air intake port60and the pumping chamber50, and an outlet check valve82is located in each of the more outlet fluid passageways66between the pumping chamber50and the air distribution pad70.

As best seen inFIGS. 7 and 8, one or more peripherally and upwardly extending channels90are provided in the insole46and/or midsole44and extend from cavity71to provide fluid communication between the pumping chamber50and the porous middle layer24of the upper20. In other embodiments, the peripherally and upwardly extending channels90may also or may alternately connect directly to the outlet fluid passageway66and extend through the insole and/or midsole and extend from cavity71to the perimeter thereof to provide fluid communication between the pumping chamber50and the porous middle layer24of the upper20.

Pumping chamber50is being operable by periodic pressure applied thereto by a wearer walking in the shoe10, which causes air to be drawn into the pumping chamber50from the external air intake port60through the inlet fluid passageway62and then expelled from the pumping chamber50through the outlet fluid passageway68to the air distribution pad70, and from the upper20through the inner layer perforations28to the porous middle layer24of the upper20to the outer layer vent openings30.

The present invention provides a shoe with an air circulation system which circulates cooling air underfoot and through a layer of the upper though the pumping action of the pumping chamber.