Safety Evaluation of Gas Generators for Seatbelt Tensioners

Several explosive devices have recently been developed to enhance general safety. Some examples are air bags which protect the driver from injury in car collisions, and seatbelt tensioners which, when tied up with the action of an air bag, hold the driver to the seat. Explosives are also used as a source of shock waves in medical equipment for breaking up gall stones in a patient s body. In yet another application, explosives are used to generate shock waves in a patient s body water which are then focused on a kidney stone to break it. 

Historically, explosives were invented in ancient China for use as a kind of medicine with ignition quality , called fire medicine in Chinese. But these devices are dangerous and can cause accidents. Therefore, safety evaluation should be carried out in parallel with their development. 

The authors have participated in safety evaluations of imported air bags and seat belt tensioners and have acquired some experience in evaluating these devices. The authors conducted a safety evaluation of the gas generator used for seat belt tensioners developed by Pyro Safety Device Corp., cooperating with engineers from this corporation. The results of this evaluation are presented here, with the kind permission of the corporation. 

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