Mercedes-Benz adopts rear seat-belt airbag

Beltbag rduces strain on passenger's ribcage in head-on collision

Published: July 20, 2012, 3:00 PM

Mercedes-Benz Beltbag - Mercedes-Benz Rear Seat-belt Beltbag

Mercedes-Benz says it will introduce an inflatable rear seat-belt airbag, called the Beltbag, on a new luxury-class model.

The Beltbag, which was first seen in Mercedes' ESF 2009 Experimental Safety Vehicle, is said to reduce the risk of injury to passengers in the rear in a head-on collision by lessening the strain placed on the ribcage.

Ford was the first company to offer an inflatable rear seat belt on its 2011 Explorer.

If crash sensors in the vehicle detect a severe frontal impact, the airbag control unit will trigger deployment and inflation of the Beltbag.

A gas generator then inflates the multi-layered belt strap with Velcro seams to nearly three times its normal width. The resulting larger surface area is able to better distribute the force acting on the seat occupant, thereby reducing the risk of injury.

The Beltbag can be used in exactly the same way as a conventional seat belt, although it's design is different. It is said to have received "top marks" in practical trials for being extremely comfortable to wear and for its extra-soft belt strap edge.

The Beltbag was developed with a particular consideration for new markets, where the occupancy rate in the rear is as much as 30 percent – much higher than in Europe.

Seat belts in the second row of Mercedes-Benz models are already equipped with belt tensioners and belt force limiters.

"The excellent standard of safety offered by Mercedes-Benz doesn't just apply to all model series, but to all seats, too," said Prof. Dr.-Ing. Rodolfo Schöneburg, Head of Passive Safety and Vehicle Functions at Mercedes-Benz Cars.

There are no plans to introduce the Beltbag for front occupants as full airbags are already included in the front on all models as a supplementary restraint system.