WinnipegFord5.com

2 + 2 = 5
The math may not work, but in this case the sum is more than equal to the parts.

Ford researchers have come up with a combination airbag and seatbelt, called a "belt bag," that will reduce injuries that have plagued the safety community for years - head, neck and chest injuries for rear-seat occupants.

The inflatable belt will be especially beneficial to passengers at both ends of the age spectrum - children and seniors - whose skeletal structure is more susceptible to damage during crashes.

In the case of the very young, the bones are not yet hardened enough to withstand the forces of a crash, while those of older passengers have become brittle and are more easily compromised.

The industry's first production inflatable seat belts will debut on the next-generation Explorer, to be introduced in 2010, but will be used in other Ford family products globally as development allows.

The concept is the same one that results in the provision of collapsible structures and additional crush zones: spread forces over a greater area. In the case of the new rear belts, instead of having the considerable force of a crash concentrated on a narrow belt positioned across the upper body, those forces will now be spread over an area five times that size.

The reduction in pressure on the chest and more controlled distribution and absorption of those forces also helps control head and neck motion of the rear-seat occupants.

In addition to reducing the forces acting directly on the chest and rib cage, the new belts also benefit internal organs through the more controlled absorption of energy.

And as a bonus, they are more comfortable.

Ford says more than 90 per cent of research participants indicated the inflatable seat belts "are similar to or more comfortable than traditional belts" because they feel padded and are softer.

It says this could help increase the lower rate of rear belt usage.

Sue Cischke, Ford's vice-president of safety engineering, says the new technology will enhance safety for rear-seat passengers of all ages, "especially for young children who are more vulnerable in crashes."

The new belts are designed to operate just like conventional belts in normal day-to-day use and are compatible with currently approved child safety seats and booster seats.

In the event of a frontal or side impact of sufficient force, a series of sensors call for deployment of the airbags - folded accordion-like within the upper portion of the rear belts -within 40 milliseconds of the event. The deployed bag forms a tubular structure with a surface area five times greater than a conventional flat belt.
This not only minimizes the forward motion of the torso, absorbing energy in the process, but also helps position the occupant in the proper position to provide maximum protection for the head and neck.

The belt bags inflate with cold compressed gas rather than the faster heat-generated chemical reaction used for other airbags.

The slower deployment and lower pressure of the new belt bags is possible because they do not have to be in place as quickly as conventional air bags, designed to be fully inflated and in position before the arrival of the body or head thrown toward them by the forces of a crash.

The compressed gas for the belt bags is contained in a special cylinder located under the seat. It flows through a special buckle into the bag folded within the belt, breaking through the fabric of the belt as it inflates, much the same as a conventional airbag breaks though the instrument panel, seat side or headliner during deployment.

As it fills with air, the belt bag is designed to expand sideways across the upper torso of the occupant in less time than it takes the vehicle to travel a single metre at highway speed.

After deployment, the belt remains inflated for several seconds before the air inside is dispersed through the pores of the fabric.

Ford says that although the system appears simple and logical, it required extensive testing over several years to ensure "precise, reliable performance in a crash situation."

Ford worked with Key Safety Systems on the belt bags. The supplier of airbags, belts and other safety systems developed the compact cold-gas inflator.