On this day in 1994 Israel Siegel was granted the patent for GRAVITY POWERED SHOE AIR CONDITIONER. U.S. Patent No. 5,375,430.
A compressor-expander type cooling, or heating system is incorporated into a heel of a shoe, and is powered by reciprocal gravity pressures upon the shoe which occur naturally during walking. The cooling system functions through a bellows compressor chamber and a separate bellows expander chamber. The movable walls of the expander and the compressor are placed opposite each other and transmit opposing vector forces to each other. A movable heel portion at the bottom of the shoe transmits movement to the movable person wearing the shoes steps on the heel. This expands the expander and compresses the compressor. A network of heat exchange coils, containing a low boiling point liquid, communicates with the expander, and functions as heat absorbing evaporator. Another network of heat exchange coils communicates with the compressor chamber, and functions as a heat delivering condenser. Depending on the locations the evaporator and the condenser networks, the shoe can serve as a foot cooler or warmer.
