Enhanced fit and comfort are imparted to a shoe vamp by a double buffered air cushion assembly having an inner air cushion and an outer air cushion wherein the inflation pressure of the inner air cushion is greater than that of the outer air cushion for providing different buffering and shock-absorbing...http://www.google.es/patents/US5902660?utm_source=gb-gplus-sharePatente US5902660 - Double buffered air cushion assembly
