The Evolution of the Airbag

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Skilled automotive trades professionals need to know how every part of a vehicle works. This week we’re going to look at a common safety feature and how it was developed: the airbag.

Airbags are an idea that has been in development since 1941, with the first patents being placed in the early 50’s. In their earliest form, they came pre-deployed, just air filled bladders for extra cushioning in the event of accidents. The deployment system has been the largest challenge in their execution. In function, an airbag has to inflate fast enough at point of impact to provide instantaneous cushioning.

In a modern vehicle, these air bags prevent occupants of a vehicle from ricocheting around during an accident. The may be placed anywhere a passenger can impact against. This includes:

  • Frontal airbags, usually in the dashboard and steering wheel
  • Side airbags, which are generally ‘curtain’ or ‘torpedo’
  • Seatbelt airbags, in the safety belt itself
  • Knee level airbags, for leg protection
  • Seat airbags, which reduce pelvic damage
  • Pedestrian, which are placed to protect people outside a car

The most common configuration is in front of the driver and front passenger seat. Backseat air bags are less common, among many reasons because they present a child safety hazard. With the smaller size of child passengers, airbags cannot deploy at a safe height. This is, incidentally, one of the reasons why safety guidelines demand that children below a certain size and weight travel in the back seat. That is also why air bag technology is taught in auto mechanic courses.

The first-known design of a deploying air bag, simultaneously worked on in Germany and the United States, tried using a quick release burst of compressed air. This was not fast enough to provide adequate protection. It wasn’t until 1963 that a Japanese inventor, Yasuzaburou Kobori, came up with a more reliable system, the first prototypes of what is used today. Although he received patents in 14 countries, the technology was still in its infancy and needed further refinement.

Airbags need to deploy within a 30 millisecond window, but a deployment system is only as good as the crash detectors behind it. That took until 1967, with a magnet and ball system. Airbags had also started using sodium azide and other non-oxygen alternatives. From that point on, airbags were an experimental extra in the 70s, available in some cars manufactured by Ford and General Motors, and with some work done by Chrysler and an Italian company.

It wasn’t until the 80s and 90s that airbags saw more common availability. Initially offered as extras, airbags are increasingly becoming part of the standard safety package included with many cars.  These days, they’re seen as a great supplement to seatbelts and car companies continue to improve every aspect of their function and find new uses for them. As a result, installing and replacing airbags is a standard skill in trades training. Airbags are universally a single use only technology, and must be replaced every time it inflates.

Want to see one in action? Check out this clip of an airbag deployment:

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