1953

Automobile Airbag

Walter Linderer (Dates Unavailable), John Hetrick (Dates Unavailable)

You are driving your car on a backcountry road when you see a deer leaping from the woods on your left, straight for your car. You swerve right. The swerve to the right is a natural instinct. Unfortunately, directly in your new path lies a giant oak tree. You are going 40 mph (65 kph). The tree is 10 feet (3 meters) away. Simple math says you will hit it in about one-tenth of a second. Your brain will never respond in time.

Let’s slow time way down here. The leading edge of the front bumper touches the tree. As your car moves forward, several engineers will be doing you a big favor. One of the engineers designed crumple zones into the sheet metal. The entire front of the car is going to collapse like an accordion to absorb some of the impact. Another engineer worked on the engine mounts. The engine is going to fall underneath the car instead of landing in your lap. A third engineer created a safety cage around the passenger compartment. It will be an amazingly strong bubble of integrity in this accident. A fourth engineer worked on the seat belt, which will automatically lock and keep you from flying through the windshield. Even the windshield is engineered to keep shattered glass from puncturing your face.

And then a sixth engineer will unleash an explosion, creating a cloud of gas that can rapidly fill a big cloth bag. Instead of your head slamming into the steering wheel, it will hit this rapidly inflating bag. This is the driver-side airbag.

An accelerometer tells a computer that it is time to deploy the airbag. The computer fires a squib, which ignites the explosive charge. The charge goes off, creating the high-speed cloud of gas. The airbag explodes out of the steering wheel just in time to meet your approaching face. The whole sequence takes just a few milliseconds.

The original invention of the airbag was credited independently to two men: German engineer Walter Linderer, and American industrial engineer John Hetrick, who both received patents for the device in 1953.

SEE ALSO ENIAC—The First Digital Computer (1946), Anti-Lock Brakes (1971).

A crash test dummy demonstrating the efficacy of an airbag.