A seat restraint
system whose
torso belt includes an
inflatable structure that inflates upon
impact to protect the occupants of a vehicle such as an automobile. The
torso belt is secured to an anchor arm that is pivotally mounted on a side surface of a seat of the vehicle or a side structure of the vehicle. The anchor arm is rotationally biased to remove slack in the
torso belt and locks up in the event of a vehicle
crash or sudden stop. The
inflatable structure is linked to a
gas generator and
crash sensor. The
gas generator may be mounted in the seat or within the anchor arm itself. When an
impact above a predetermined level of severity is detected, the
gas generator is ignited, inflating the
inflatable structure which contracts in length as it inflates. In a preferred embodiment, the inflatable structure is a braided tube. As the braided tube inflates, the
diameter of the tube increases significantly and its length decreases significantly, due to the orientation of the fibers comprising the braided tube. The contraction in length pretensions the
seat belt system by pulling any additional slack out of the
seat belt systems. In a frontal
impact, the inflated structure restricts the forward motion of an occupant and distributes
crash loads over a larger occupant surface area to reduce both primary and secondary injuries. In a
side impact, the inflated structure passes over the occupant's shoulder, restricts occupant motion, distributes crash loads and provides
head and neck protection.