In recent history, there have been some amazing inventions which have changed our lives. The plane has made international travel faster and easier. The Internet has brought people closer. And you must know the names of some famous inventors like Henry Ford or Steve Jobs. But there are many everyday objects which you probably don't notice and you don't know who invented them. Take for example Nils Bohlin who invented the modem-day car seat belt (安全带).
Before 1959, only two-point seat belts were available, and the only people who often wore them were race car drivers. The two-point seat belt couldn't protect passengers from internal injuries (内伤) during serious car accidents.
In 1958, Bohlin joined Volvo Car Corporation as a safety engineer. Then he came up with the three-point seat belt to keep passengers from flying out of their cars during collisions. The three-point seat belt used one strap (带子) across the chest (胸部) and another across the legs and then the two joined at me same place.
Amazingly, this was a very simple idea which no one had tried before. The three-point seat belt was introduced on Volvo cars in 1959. For more people's safety, Volvo made the new seat belt design available to other car makers for free. Since then, engineers have worked to improve the three-point seat belt, but the basic design remains Bohlin's.
At the time of Bohlin's death in September 2002, Volvo announced that the seat belt had saved more than one million lives since it was introduced.