The three-point seat belt, which is widely used today, was invented by a Swede working for Volvo. Nils Bohlin (1920 - 2002) was an aircraft designer at Saab, tasked with developing ejector seats, before joining Volvo in 1958 as a Safety Engineer.
Back then, the seat belt was a lap belt just like in airplanes, and this design caused internal organs to rupture, especially in car crashes while driving at high speed.
Bohlin set out to find a simple, comfortable alternative that would protect both the upper and lower body. The three-point seat belt solution allowed occupants to fasten the seat belt with one hand using a buckle located near the hip and a strap between the chest and lap. The design spread the impact of the collision more evenly across the body, significantly reducing potential injuries and also preventing the driver or passenger from being thrown out of the car in car crashes while driving at high speed. Bohlin claimed that the design worked because it was not only comfortable and easy to use, but also safer.
Volvo began incorporating the new seat belt into their cars manufactured in Sweden from 1958, and other automakers soon included them in their cars. In 1970, the Australian state of Victoria passed the first traffic law requiring drivers and front seat passengers to wear seat belts. Since then, many countries have made seat belt laws. Volvo first introduced the three-point seat belt for rear seat passengers in 1972.
The National Highway Traffic Safety Administration estimates that seat belts reduce the risk of death in a car accident by 45 percent and prevent more than 100,000 injuries in the United States alone.
Nils Ivar Bohlin (17 July 1920 – 21 September 2002) was a Swedish mechanical engineer and inventor who invented the three-point safety belt while working at Volvo.
Who is Nils Bohlin?
Nils Bohlin was born on 17 July 1920 in Härnösand, Sweden.
He graduated with a bachelor's degree in mechanical engineering in 1939.
He started working for Svenska Aeroplan Aktiebolaget (SAAB) in 1942. While working here, he held various positions. It is even known that he designed a rocket launch seat and received a patent for himself. Before this seat design, the mechanism that ejected the seat had injured the pilots a lot.
Again in this process, he also designed a seat belt to provide evacuation from the emergency exit door of an aircraft used for civil aviation without injury.
Volvo 3-Point Safety Belt from David Hildreth on Vimeo.
Invention story
The experience of safe travel, which started in the 1920s when American doctors tried to create serious public pressure on the use of seat belts in cars, was provided with a two-point lap type belt at that time. However, these belts could not adequately and effectively protect their users, especially at high speeds. That's why Swedish company Volvo came up with the first solution to produce safer cars and in 1957 added a two-point diagonal seat belt lock.
Even though Volvo found a solution, it wasn't enough and while looking for more reliable solutions, an engineer named Nils Bohlin invented the three-point belt design. Thus, Volvo became the first company in the world to put the three-point seat belt “as standard” on its cars on August 13, 1959. That model was called the Volvo PV544.
Although Volvo received a patent for its invention, it paved the way for other automakers to use this system widely by obtaining a patent for this new invention, known as an "open patent", where anyone can use its design free of charge.
Nils Bohlin's three-point seat belt design consisted of a lap belt and diagonal body belt system, with the belt straps fastened down on the seat side, drawing a V with the end of the belt facing the ground. In this way, the position of the belt did not deteriorate and it did not move under load.
Despite Volvo's more secure belts, seat belts were not found to be costly in New York in the early years, but by the 1960s, seat belts had become a standard. Until 1965, seat belt standards were determined in America and Australia and production started. In 1969, three-point seat belts in the front seat were made mandatory in Sweden. Mercedes-Benz offered the three-point seat belt as standard in the rear seat.
Striking data were revealed with the report presented by Volvo at a traffic safety conference held in the USA in 1967. The report was based on data from accidents involving Volvo cars over a year in Sweden. The report clearly pointed out that seat belts save lives and can also reduce injuries by about 50-60%. In this way, the importance of seat belts began to be understood all over the world.
Working with other safety systems such as airbags, Volvo's three-point seat belt, which was used in the front seats in 1959 and in the rear seats since 1967, constitutes the cornerstone of interior safety equipment in cars. The seat belt, which has saved the lives of more than 1 million people in 61 years, seems to be one of the indispensable safety equipment in automobiles in the future.