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Publication honors Michelin's airless tire co-inventor

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Michelin's Tweel airless tires
Michelin's Tweel airless tires are in use on this skid-steer loader.

GREENVILLE, S.C.—The co-inventor of Michelin's Tweel airless tire has won an award.

Engineering News-Record gave its 2014 Award of Excellence to Tim Rhyne, a senior research engineer with Michelin Americas Research and Development Corp. and co-inventor of the Michelin Tweel—a non pneumatic tire/wheel combination.

The Tweel comprises a rigid hub connected to a shear band by means of flexible, deformable polyurethane spokes and a tread band, all functioning as a single unit.

“We see vehicle manufacturers and drivers really don't like the idea that tires go flat,” said Tim Fulton, head of Michelin Tweel technologies. “In commercial applications, it costs commercial operators a lot of money. That very notion of Tweel is an idea that's very seductive to the market.”

Rhyne said he and Steve Cron, a fellow engineer and co-inventor of the Tweel, developed the idea of exploring alternatives to the pneumatic tire. The inventors ultimately sketched a radial tire that didn't require any air.

In 1997, Rhyne said Cron had the Eureka moment, which involved replacing the air pressure with a beam. Rhyne sketched the picture, and the idea had legs.

“It was a lot of serendipity after we drew the picture. We didn't really understand how good it could be,” Rhyne said. “It was just kind of luck, but it's taken a long time to develop the idea and prove it out.”

The Tweel concept tire/wheel combination was introduced in 2005. Michelin started small with its new product, developing the first commercial Tweel to supply the iBot wheelchair.

Tim Rhyne
Tim Rhyne

“The pneumatic tire industry, if you look at it for every type of vehicle, you span a huge gambit of things from wheelchairs or wheelbarrows all the way to space shuttles,” Fulton said. “When you come up with new technology like this, you're not necessarily shooting for the space shuttle as your first target. You're trying to make something that works and then evolve it to increasing challenging and larger markets.”

Rhyne and the team continued development of the Tweel through 2008 but hit a wall when the economy turned bad. Michelin eventually took it off the shelf in 2012, when Fulton said customers were asking about the product.

That also aligned with the firm's desire to break into new technologies—such as the Tweel. One segment Michelin wanted to grow in was the mobility segment.

The Michelin X-Tweel SSL was launched commercially for skid steers in October 2012 and is currently being marketed for commercial off-highway applications, mainly construction where flat tires can cause major setbacks.

Steve Cron
Steve Cron

“The overall economy has changed,” Fulton said. “If you look at where we were in 2008 and 2009, the economy wasn't in great shape for launching big new ventures. Tweel is a very new innovation that's early in its maturity cycle, so it has a lot more risk.”

As for the future of the Tweel, which is produced at the firm's Greenville facility, Michelin remains committed to focusing on small off-road machines, though Fulton said down the road it could be marketed for the automotive industry. Michelin hopes to increase the number of models to between 10 and 24.

Rhyne began his career at Michelin in the machine design group in 1978 and has served in several research and development positions with the French tire maker's North American company. In 1986, he began work in tire development and by 1996 was working exclusively in the tire research area.

He since has been working with a team devoted to conceiving and developing new mobility concepts.