Supplementary Restraint Systems: Part two - Seat belt pre-tensioners

摘要

Although airbags have saved countless lives over the years, the real experience of the crash protection system can be traumatic. In countries where the wearing of a seatbelt is not compulsory and not worn, the deploying airbag can cause injury. The problem is that the air bag is generally a "one size fits all" device. Because impacts can vary in direction and speed and passengers are not all of the same size or weight, the force of the airbag can be either excessive or insufficient. The purpose of the airbag is to cushion the force of impact. If this can be shared by the seatbelt, then the demands on the airbag are reduced. But if the seatbelt is loose, unrestrained movement can take place before the slack in the belt is taken out. This hammer effect can cause injury to the skeleton and internal organs. The seat belt pretensioner takes out the slack in the belt at the point of impact.