9.4.1 Seat belts
Seat belt is the first means of passive safety system It is designed to save people from serious injuries in case of collisions. It keeps a person from flying towards in case of collision. Three-point seat belts are used nowadays. This means that the person is fastened with a belt at three points: one point is shoulder, and the other two - lumbar.
Always fasten your seat belts, no matter how far and how fast you drive.
With the development of technology, seat belts have also evolved. This is how inertial seat belt tension coils were invented. Inside the case, the belt is wound on a spool. Operating principle of such coils is simple: when it is necessary to extend a belt and to fasten it, the coil unwinds and length of a belt increases. However, in case of sudden braking, i.e. in case of a sudden impact on the belt, the coil is locked, thus preventing the belt from stretching more than necessary, further holding the driver.
But the designers did not stop there: they invented and implemented a system of pre-tensioning seat belts. And if in the case of inertial coils, the belt simply does not lengthen, the system of pre-tensioners in case of a collision additionally tightens the seat belt, thereby reducing the load from the impact on the airbag and eliminating the possibility of the driver slipping under the belt.