This study asks if it possible to obtain both the thoracic injury mitigating benefits of an air bag only restraint and the all-impact-direction benefits of the belt from a restraint system combination by adding a force limiter to the shoulder belt. For this reason, tests with force limiters were performed. The force limiter with the level of 4 kN showed, through examination of the chest band contours, a more bag like uniform compression of the chest and reduces therefore the injury risk. Non or AIS 1 injuries were found in the cervical spine and AIS 0 to AIS 1 was observed in the thorax, even in the age range 60 to 65 years. The chest compression amounts to 4 to 8 cm, and the resultant vertebral accelerations were in the average 30 to 40 g's; at these levels the thorax of the most cadavers remained uninjured or an injury severity of AIS 2 was observed. It is concluded that when a driver side air bag is combined with a 3-point belt system that limits the torso belt loop load to 4 kN, additional injury mitigation benefits for both the cervical spine and the thorax are obtained in frontal collisions. (A)
Abstract