Steven M. Cron is a retired

Michelin Michelin (; ; full name: ) is a French multinational tyre manufacturing company based in Clermont-Ferrand in the Auvergne-Rhône-Alpes ''région'' of France. It is the second largest tyre manufacturer in the world behind Bridgestone and la ...

product research engineer and co-inventor of the

Tweel The Tweel (a portmanteau of ''tire'' and ''wheel'') is an airless tire design developed by the France, French tire company Michelin. Its significant advantage over pneumatic tires is that the Tweel does not use a bladder full of compressed air ...

. Cron began his engineering education with a BS Mechanical Engineering degree from the University of Missouri-Columbia in 1984. In 1985, he completed an MS degree in aeronautical engineering from the U. S. Air Force Institute of Technology at

Wright-Patterson Air Force Base Wright-Patterson Air Force Base (WPAFB) is a United States Air Force base and census-designated place just east of Dayton, Ohio, in Greene County, Ohio, Greene and Montgomery County, Ohio, Montgomery counties. It includes both Wright and Patte ...

. He then continued with the Air Force for 6 years as a project engineer working on

ICBM An intercontinental ballistic missile (ICBM) is a ballistic missile with a range greater than , primarily designed for nuclear weapons delivery (delivering one or more thermonuclear warheads). Conventional, chemical, and biological weapons c ...

s and as an instructor of Engineering Mechanics at the US Air Force Academy. He began his career at Michelin in 1991 as a research engineer. He had initial assignments in the area of tire

vibration Vibration is a mechanical phenomenon whereby oscillations occur about an equilibrium point. The word comes from Latin ''vibrationem'' ("shaking, brandishing"). The oscillations may be periodic function, periodic, such as the motion of a pendulum ...

s, specifically damped

modal analysis Modal analysis is the study of the dynamic properties of systems in the frequency domain. Examples would include measuring the vibration of a car's body when it is attached to a shaker, or the noise pattern in a room when excited by a loudspeak ...

of pneumatic tires via the

finite element method The finite element method (FEM) is a popular method for numerically solving differential equations arising in engineering and mathematical modeling. Typical problem areas of interest include the traditional fields of structural analysis, heat ...

. He began work on airless tire technology as early as 1997, with work on the Tweel occurring over the period 2000-2009. Although other airless tire concepts have been studied or attempted in the past, none has achieved the commercial success of the Tweel, which is based on the framework and approach pioneered by Cron and co-inventor Timothy B. Rhyne. In 2018, Cron received the Harold Herzlich Distinguished Technology award. At the time, Cron said that work on the Tweel began informally, starting with the idea that the load of the vehicle should be carried in the tire structure by means of tension, as happens in a traditional pneumatic tire. After realizing that cord tension carried via the sidewall would not work with zero inflation pressure, a successful experiment with polyurethane spokes lead to the basic Tweel design. In 2021, Cron and co-inventor Timothy B. Rhyne were jointly awarded the

Charles Goodyear Medal The Charles Goodyear Medal is the highest honor conferred by the American Chemical Society, Rubber Division. Established in 1941, the award is named after Charles Goodyear, the discoverer of vulcanization, and consists of a gold medal, a framed c ...

, the highest honor conferred by the

American Chemical Society The American Chemical Society (ACS) is a scientific society based in the United States that supports scientific inquiry in the field of chemistry. Founded in 1876 at New York University, the ACS currently has more than 155,000 members at all d ...

, Rubber Division. It was the first time that the award was given jointly.

References

Polymer scientists and engineers Tire industry people Year of birth missing (living people) Place of birth missing (living people) University of Missouri alumni Air Force Institute of Technology alumni Living people Michelin people {{US-engineer-stub