The Seat Belt Tensioners (SBT) are equipped with a force limitation device which reduces the force of the belt on
the passenger’s body, without affecting the protective function of the seat belt during an impact.
SEAT BELT TENSIONER — FUNCTIONALITY
In the event of a collision, the Occupant Restraint
Controller (ORC) puts out an electrical signal for trig-
gering the Seat Belt Tensioner (SBT) after a certain
delay.
The Squib in the gas generator is triggered and the
resulting combustion gas moves the piston (2) in the
gas generator cylinder (3) up at high speed. The pull
cable (4) connected to the piston is tensioned causing
the cable pulley (5) to turn. Inertia and centrifugal
force cause the pawls (7) in the cable pulley (5) to
engage in the teeth in the toothed ring (6).
A positive connection is then present between the gas
generator piston and the seat belt retractor shaft via
the pull cable (4), the cable pulley (5) and toothed
plate pulling and thereby tensioning the seat belt (1).
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RESTRAINTS - SERVICE INFORMATION
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