The somewhat dated FMVSS 208 regulation requires that crash dummies are belted with no slack.
Reality shows that there is 120mm slack in the belt system for a 50 percentile occupant. Test results would yield more then 20% worse injury indexes when taking slack into account.
This presentation will show how pretensioners can reduce injuries, giving a historical perspective from spring loaded systems to current pyrotechnic systems. Future developments using multi-cartridge and multi-piston systems and associated test results will be discussed.