Superior Innovations for Extra Safety and Comfort. Effective Protection in a Collision from the Rear. Crash-Activated Headrests.

In autumn 2007 occupant safety in BMW cars is being further optimised
through the introduction of crash-activated headrests: All models in
the BMW 6 and the BMW 5 Series, as well as the BMW X5 and BMW X3, now
come as standard with these newly developed headrests significantly
reducing the risk of cervical vertebra injury in the event of a
collision from the rear. Masterminded by the car's safety electronics,
these crash-activated headrests move up to 60 millimetres or 2.36"
forward and up to 40 millimetres or 1.57" upward within fractions
of a second in the event of a collision, reducing the gap between the
headrests and the occupant's head before his head can be thrown back by
the forces acting on the car. This enhances the stabilising safety
function of the headrest and minimises the risk of injury or
over-stretching the occupant's cervical vertebrae. The cervical
vertebra (CV) syndrome also referred to as the whiplash trauma is one
of the most common types of injury in traffic accidents and is caused by
sudden impacts from behind. Highly painful in many cases, such a
trauma may even result from a rear-end collision at low speeds in city
traffic. To avoid collisions of this kind, BMW introduced two-stage
brake lights back in 2003, the illuminated area of the brake lights
becoming larger whenever the driver applies the brakes particularly
hard, thus giving motorists following from behind an absolutely clear
and informative signal, telling them to brake hard too. And now the new
crash-activated headrests offer the occupant of a BMW additional
protection in such a situation, whenever a collision can no longer be
avoided. Comfortable, safe, individually adjustable. From outside the
crash-activated headrests can be clearly distinguished through their
modern, two-piece look formed by the headrest support and the impact
plate together with its padding moving variably as required to the
front. At the side, in turn, the padded section features a button for
manual adjustment of headrest depth in the interest of enhanced driving
comfort, enabling the user to vary the position of the padding within
three different levels by up to 30 millimetres or 1.18". In a
collision the impact plate together with the padding will
instantaneously move forward by up to 60 millimetres or 2.36",
reducing the gap between the headrest and the occupant's head. And at
the same time the impact plate and padding will move up by up to 40
millimetres or 1.57". A second variant of the crash-activated
headrest has been developed for BMW's comfort seats, in this case
featuring side supports stretching along the entire height of the
headrest padding. This new version replaces the former active headrests
on the comfort seats. Activated by the airbag control unit. The
interior of both types of crash-activated headrests comprises complex,
spring-driven mechanical operating units activated by a pyro-actuator.
As soon as the pyro-actuator ignites, it propels a release stick moving
a release plate and setting two adjustment springs free. These springs,
in turn, move the impact plate and the headrest padding both forward
and upward.The pyro-actuator receives its ignition signal from the
airbag control unit as soon as the sensors detect a relevant impact at
the rear of the car, this system developed by BMW thus acting very
quickly and efficiently in protecting the occupants from whiplash
trauma. The new crash-activated headrests enhance not only the
stabilising and safety functions of the headrest, but also the level of
comfort while motoring. Conventional headrests set to the right
position are often perceived as too close to the occupant's head and
therefore appear to limit his freedom of movement. The new
crash-activated headrests, in turn, provide not only enhanced safety,
but also an improved feeling of space, since they are not required to
rest directly on the occupant's head while driving. Once the safety
mechanism in the crash-activated headrests has been actuated, an
appropriate Check/Control message will appear in the instrument cluster,
reminding the driver to go to a BMW workshop in order to renew the
pyro-actuator in the release system.