Samenvatting
A pretensioner is a device that actively withdraws a portion of belt (about 10- 15cm) during the impact, in order to keep the car occupant adherent to his seat and prevent contacts with the steering wheel, or with dashboard components. A research has been performed on a mechanical pretensioner, on a pyrotechnical pretensioner and on standard automatic seat belts, with and without slack. The laboratory results show a significant reduction in HIC vs standard belts, especially when poor wearing conditions are present (slack).