| abstract |
The present invention is a self-ventilating insert for footwear with a wedge-shape pumping chamber located in the heel of the footwear. The pumping chamber can displace an air volume of at least about 44 cubic centimeters plus 3 times the U.S. men's footwear size. The pumping chamber has convex side and rear walls that fold together as the pumping chamber collapses. Maximum air circulation is achieved as the upper and lower surfaces of the pumping chamber come into full contact with each other. In a preferred embodiment, the length of the pumping chamber is between 30% and 60% of the length of the sole. The internal air duct, in a preferred embodiment, has a thin, wide cross-section with a plurality of tubes that resist kinking and pinching action near the flex zone of the footwear. |