Like the design fitted to the front seats in many Mercedes-Benz vehicles, the new active seatbelt is initiated when Pre-Safe sensors anticipate a crash. Pre-Safe reacts in hazardous situations, such as when an object is detected in a dangerous buffer zone near the vehicle, or when the on-board computers notice the vehicle is not at ease.
The seat belt is able to tighten and firmly secure the passenger, reducing sideways and forward movement. It aims to reduce the chance of passengers moving about in the cabin.
Using an electric motor, the buckle itself is capable of increasing tension by up to 80mm when Pre-Safe is activated. For added convenience, this same mechanism extends out by 70mm to assist in buckling up upon entry to the vehicle.
Once the belt is locked in, the buckle retracts and takes up unnecessary slack. This function, up until now, has only been available on front seat belts. Prof. Dr. Ing. Rodolfo Schöneburg, head of passive safety and vehicle functions at Mercedes-Benz Cars, says,
"We aim to offer a high standard of safety not only in all model series, but also in all seats. In the rear of premium saloons in particular, passengers tend to sit in particularly relaxed positions in the generous space which is available.
"Active seatbelt buckle as part of Pre-Safe unlocks the full potential of the on-board restraint systems."