Pre-tensioner for a three-point safety belt system for vehicles

摘要

The invention relates to a pre-tensioner for a three-point safety belt system for vehicles with a cylinder-piston unit (2) and a clamping device (3) for a belt webbing (4). According to the invention the cylinder-piston unit (2) comprises an outer tube (5) and an inner tube (6) contained in this. A pyrotechnic charge (9) is fitted on the outer tube (5), which charge can be ignited into a combustion chamber (14) of the inner tube (6). Such an arrangement takes up little space and the pressure behaviour on combustion of the propellant charge can be influenced and adjusted by the size and shape of the combustion chamber. IMAGE