TOKYO (Aug. 6) — Bridgestone Corp. is working on a tire design that would enable it to make higher aspect-ratio run-flat tires, a development that could lead to run-flats for sport-utility vehicles and similar automobiles.
Bridgestone claims its "cooling fin" technology — in essence protrusions on the tire sidewall that generate airflow to cool the sidewall — will allow it to engineer tires capable of carrying the higher loads required by SUVs, cross-over vehicles, mini-vans, etc.
To date, Bridgestone said, sidewall-reinforced-type run-flats have been restricted to lower aspect-ratio tires (below 60 series) because the shorter sidewall-height tires don´t heat up as much as higher aspect-ratio tires when run under- or un-inflated.
Diagrams released by Bridgestone show short vertical ridges running roughly from the shoulder to the bead around the tire. These ridges disturb the airflow past the tire, causing it to flow toward the wheel instead, cooling the sidewall in the process.
Bridgestone has filed for patents on this technology. Run-flats typically enable the driver to drive up to a specified distance at a specified speed (50 miles at 50 mph, for example) following a loss of air pressure, Bridgestone said.
The tire maker said the technology could enable it to use lighter sidewall-reinforcing rubber, thus reducing overall weight and enhancing comfort during normal driving.
The company plans to showcase the technology at various academic conferences in Japan and other key technology markets around the world.