Oh, Patents! Asics® gel soles

Copyright © Françoise Herrmann
Asics® sports shoes are known for the gel they contain inside the heel and/or forefront portions of their soles, designed to cushion or to shock-absorb impact with the ground when running or jogging, or for other types of aerobic activity. And as you probably suspect quite rightly, this technology is patented, granting negative rights to the inventor or the assignee to prevent competitors from producing, marketing, selling or otherwise licensing such a gel technology for athletics shoes.

An interesting aspect of this patented technology concerns the way the configuration of the recessed cavities containing the gel inside the soles has evolved. In an early 1988 disclosure of this invention there is a plurality of chambers filled with gel, each gel-filled cavity separated by an air chamber. In another 1996 subsequent disclosure of this invention, the evolved gel-filled cavity has a plurality of flexible partitions, some of them gating the gel flow, and others directing the gel circulation within the cavity, from one chamber containing more gel to another containing less gel.

The difference in design reflects increased knowledge of what causes injury to lower limbs, that is to knees, ankles and feet, as a result of repetitive, heel-first high-impact sports such as running and jogging, or other types of forefoot-first high-impact sports such as aerobic exercise and movement involving jumping, as in basketball or volleyball.

 Here are patent drawings of the two different inventions pertaining to soles with gel-filled cavities, and of a 2013 marketed Asics® shoe product, with walls on the side of the shoe to see the gel cavities inside the soles.

Sole [US4768295 - 1998]

Shoe comprising a liquid cushioning element [US5493792 - 1996] (The gel chambers appear dotted.)