What Is Seat Belt Pretensioner?
Pretensioner devices can be added to any of the belt anchorage points and there are typically three different types of seatbelt pretensioners.
The idea of a retractor pretensioner is to tighten up any slack in the belt webbing in the event of a crash. The main part of the pretensioner consists of a small pyrotechnic cartridge packaged inside the retractor, the buckle assembly, or the outboard anchor assembly. Retractor pretensioners may be in the B-pillar or in the seat.
Buckle pretensioners are attached to the inboard side of the front seat and is operated mechanically. It is usually connected to the seat belt buckle assembly with a long powerful spring that is compressed in a tube and is kept compressed by a latching mechanism. If an accident occurs the impact causes the latch to release the spring which pulls on the buckle assembly and tightens the seat belt.
Seat Belt Pretensioner Products