Self-Study Program

43
Ball seatbelt pre-tensioner
Both of the front seatbelt inertia reels are
equipped with pyrotechnic tensioners that
are triggered with an appropriate force in the
event of an accident.
The balls are driven by a pyrotechnical
propellant load. This kinetic energy is
transferred via a gear wheel to the belt
capsule. The seatbelt is wound up to remove
any belt slack and reduce the load on the
occupant.
Testing a fired seatbelt pre-tensioner:
There should be a clear rattling noise when
shaking a seatbelt pre-tensioner that has
been removed from the vehicle.
Belt force limiter
The additional belt force limiters in the front
inertia reels have the effect of keeping the
forces exerted on the shoulder (even in head-
on collisions) to a defined level.
A torsion spindle in the inertia reel allows for
compensation of up to 10 cm belt length.
The outer rear seats are equipped with a
3-point safety belt.
Belt force limitation is achieved by means of a
pre-defined tearing seam in the belt.
This limits the strain level placed on the
occupants in the rear seats.
SSP239_048
SSP239_046
SSP239_106
Tearing seam