Seat belt

A seat belt is a strap that holds a person into his or her seat in a car, truck, plane, or other vehicle, so that in a crash he or she would not be injured or killed by flying forward and hitting parts of the vehicle or being thrown out of it. They are helpful in saving lives in car accidents. 
In 1946 a doctor in Pasadena, California proposed better seat belts than were used then. In 1955 several improved seat belts were patented. Automobile manufacturers sold many more cars with such seat belts, starting then. Eventually, laws required cars to have them.