Tech Briefs
Seat belts that think like airbags

When deployed, the SmartBelt system gently pushes an occupant back in the seat. BFGoodrich says the SmartBelt system is applicable to a variety of vehicles from aircraft to school buses.

An aerospace company, The BFGoodrich Co., has intro- duced a new technology to the automotive market that was originally designed for use in aircraft. According to the company, its SmartBelt systems work with existing vehicle airbags to protect drivers and passengers. During a significant crash, the systems rapidly inflate a bladder that runs the length of the belt from the buckle to the point where it enters the upper part of the seat or pillar. The systems are expected to be available to the public within two years. In initial applications, SmartBelt systems will provide added protection in cars for back-seat passengers. The company expects the product to become a standard feature in cars and possibly planes, trains, and school buses within a few years.

SmartBelt systems were designed by the Safety Systems Division of BFGoodrich Aerospace. "The inflatable seatbelt provides airbag-like qualities while deploying away from the wearer and then cradling him or her into the impact," said Mike Vecchio, Safety Consultant for BFGoodrich.

The SmartBelt systems create additional protection for smaller occupants and especially children. Because the new systems inflate within the first 10 ms of a crash, and airbags deploy after 25-30 ms, the wearer becomes "prepositioned" by the SmartBelt to more safely accept the force of the airbag, optimizing the airbag's ability to protect. The company claims that the SmartBelt system out-performs airbags and seatbelts in side-impact crashes and offers improved rollover protection, even in convertibles. It also cites tests that have shown that with SmartBelt a driver or passenger would sustain considerably less head injury than one using traditional airbag/seatbelt combinations.

SmartBelt systems feel just like a traditional seat belt. Because it is a seatbelt as well as an inflatable restraint, it can be adjusted for comfort and maximum protection. Seatbelts protect but can also cause pain, and in some cases, even severe injury because the force between a body and a seatbelt can be tremendous—up to 55 times the force of gravity. SmartBelt systems provide an additional cushion for the occupant and distribute force over a wider area on the body because the belt's bladder expands to a full width of 15 cm (6 in).

SmartBelt systems is basically a seatbelt that thinks like an airbag. Its proprietary Direct-Thermal inflator forms the foundation of this technology along with the integration of space age materials. These materials are both strong and light allowing this new innovation to produce its improved safety benefits. The Direct-Thermal inflator's design allows for the use of less propellant than traditional inflators, which in turn yields a smaller package size. In addition, it has a unique gas discharging method, permitting a wide range of gas diffusing options—radially, axially, transfer tubes. This allows maximum flexibility for integration into upstream module applications in all safety system locations.

BFGoodrich originally exited the automotive tire industry in 1986 after selling its tire business to Michelin. Michelin still manufactures and markets tires under the BFGoodrich label.

Jean L. Broge