DETROIT - Until now, most side-impact airbags have been used by luxury makers like Audi, Lexus, BMW, Cadillac and Mercedes-Benz.
That begins to change in the 1998 model year, when side-impact bags will filter down into more popularly priced models.
The 1998 Toyota Corolla and Chevrolet Prizm, for example, will have side bags mounted in the driver and passenger front seats.
The technology has spread without a federal mandate and despite some hurdles. Chief among them: the controversy over children and small adults being killed by front airbags.
'With all the bad publicity, now many don't want that many airbags in a car,' said Gershon Yaniv, head of development for Simula Inc. of Phoenix, at the Airbag Technology '97 Conference here last week.
The focus of side airbags also is changing. Original systems, such as the seat-mounted airbag introduced by Volvo on the 1996 850 model, were designed to protect the thorax, or chest region. But new side bags are designed to protect the head, said X.Y. Soon, head of next-generation airbag module products for TRW Inc.
The head is one of the most vulnerable areas in a side impact, Soon said. The door glass is the only protection it has. In a front crash, the engine compartment helps absorb crash energy to protect passengers.
BMW has gotten a jump on competitors with its Head Protection System, an inflatable tube that pops down from the headliner and stretches diagonally across the front-door windows. BMW will make the system standard -augmenting door-mounted thorax bags already in use - on the 1998 5-series and 7-series sedans in the United States.
BMW developed the restraint with Simula, which provided the initial design, and Autoliv Inc., which contributes the inflator.
Simula originally developed the restraint to protect the head in side impacts. But the company is also testing the device as a means to prevent occupants from being thrown out of vehicles in a rollover. Simula is working with the National Highway Traffic Safety Administration on the project.
A STRUCTURAL COMPONENT
Simula says a key advantage of its system is that the restraint is anchored at the base of the vehicle's A-pillar and roof rail, making it a structural component of the car. Other designs, such as combination head-thorax airbags and side curtains, have to press up against the vehicle's side glass or B-pillar to help cushion the occupant's head, said Yaniv.
Virtually every safety system supplier is pushing ahead with development of side-impact protection for the head. Autoliv has developed a side curtain - a rectangular airbag that runs the length of the passenger compartment and deploys down from the headliner. The system will be used in future vehicles from Mercedes-Benz and Volvo.
Morton International, which merged with Autoliv on May 1, has been developing a dual-chamber, seat-mounted combination side airbag that tries to limit injuries. When the lower portion of the bag is blocked by a person's arm or body, the inflation gases are redirected to the top chamber of the bag first, filling an empty space rather than forcing the occupants body out of the way.
Still, not everyone is sold.
Breed Technologies Inc. is working on side-airbag technology, but Chairman Allen Breed is skeptical.
'I think some of the early side airbags have just been for marketing purposes,' Breed said. 'In crashes, I think they're pretty useless. I'll be interested in the results when we get 100,000 units out there.'