What is the main function of a load limiting device on a seatbelt?

The main function of a load-limiting device on a seatbelt is to automatically lock when force is applied. This mechanism works by allowing a controlled amount of seatbelt webbing to pay out under certain conditions, such as during a collision. The purpose is to reduce the forces exerted on the occupant's body by extending slightly during a crash, thereby preventing excessive force from being transmitted to the chest and shoulders. This helps in minimizing injury while still maintaining a degree of restraint.

In the context of vehicle safety, load limiters play a crucial role in the overall design of seatbelt systems. They are engineered to manage the energy generated during a crash while maintaining seatbelt effectiveness. This allows the seatbelt to accomplish its primary function of restraining the passenger while also providing a safety mechanism that slightly mitigates the impact forces that passengers experience.