DETROIT (AP) — Air bags have long been mounted in the steering wheel, dashboard and sides of vehicles. Now, they're in the seat belts.
Ford Motor Co. plans to introduce seat belt-mounted air bags in the back seat of the 2011 Ford Explorer sport utility vehicle, which will hit the market next fall. Ford says it's the first automaker to mass produce the technology.
The belts have a cylindrical air bag that stretches from the buckle to the shoulder and fits inside a pocket sewn into the belt. If the air bag is needed, the car sends a signal that releases the bag. It inflates more gently than a front air bag, and with cooler air, so it's safer for children.
Srini Sundararajan, the Ford engineer who was chiefly responsible for developing the seat belts, says the wider belts and bags help distribute crash forces across the occupant's chest, so there's less chance of a serious injury. They also help support the occupant's head and neck.
"The top two lifesaving devices today are the seat belt and the air bag. This combines them into one great feature," Sundararajan said.
Ford has been working on the technology for a decade and had to overcome numerous challenges bringing it to market.
For example, front air bags are powered by a pyrotechnic device that generates hot gas. They also deploy very quickly because they need to cover a greater distance before they reach the driver or passenger. Seat belt air bags don't have that distance to cover, so they can deploy more gently, although Srini said they're still fully deployed in a tenth of a second. They also use cold gas technology.
Ford introduced a back-seat air bag concept at the North American International Auto Show in Detroit in 2001, but the inflator was located in the trunk and it rattled around too much, bothering drivers, Sundararajan said.
39° 