Airbag - A Supplementry Restraint System

The airbag was invented by Patrick W. Hetrick of Newport, PA, U.S. in 1951. Hetrick came up with the idea to help protect his own family using expertise from his naval engineering days. Throughout the years, the saving of many lives have been attributed to Hetrick's invention. There have been devices similar to airbags for airplanes as early as the 1940s, with the first patents filed for those devices in 1958. Early air bag system origins traces back to air filled bladders.

Car designers have moved on from the initial view of the airbag as a seat belt replacement. Automobile airbags are now designed and sold as Supplemental Restraint Systems (SRS). In 1980, Mercedes-Benz re-introduced the airbag in Germany that it had patented in 1971 as an option on its high end S-Class. On July 11, 1984, the U.S. government required cars being produced after April 1, 1989 to have driver's side air bag.

Many advanced air bag technologies are being developed to tailor air bag deployment to the severity of the crash, the size and posture of the vehicle occupant, belt usage and how close that person is to the air bag module. Many of these systems will use multi-stage inflators that deploy less forcefully in stages in moderate crashes than in very severe crashes.

Occupant sensing devices let the air bag diagnostic unit know if someone is occupying a seat in front of an air bag, whether the person is an adult or a child, whether a seat belt or child restraint is being used and whether the person is forward in the seat and close to the air bag module. Based on this information and crash severity information, the air bag is deployed at either a high force level, a less forceful level or not at all.