Technology companies rely on innovative ideas to keep a competitive edge in the market place. The ability to generate intellectual property, for many companies, has a direct effect on their long term profitability. Computer simulation analysis has proven to be an ideal tool to investigate the feasibility of new ideas and concepts. Simulation analysis can give a good idea about the possibilities of a new concept, without the time and cost involved with building and testing prototypes. Knowing from the analysis what the product can do and how it is going to function is often sufficient to apply for a patent.
In 1995 a study was conducted to conceptualize a device that could mitigate lower extremity injuries. Although lower extremity injuries are not life threatening, they are often very debilitating and require long periods of rehabilitation. It is believed that bracing the legs against the toe board, during a vehicle crash, is a major contributor to the injury mechanisms. Another contributor to the lower extremity injuries is leg interaction with the instrument panel.
The Seat Cushion Restraint System (SCRS) comprises an activated seat design that acts to eliminate the interaction between the lower extremities and the vehicle interior. It also reduces the interaction between the legs and the instrument panel by limiting the forward travel of the lower torso. It achieves this by inflating an airbag device in the front part of the seat cushion, during the early stages of a vehicle crash. This lifts the legs off the toe board, effectively eliminating the bracing force. It further restrains the lower torso as effective as a lap belt which reduces the interaction of the knees with the instrument panel.
Computer simulations helped to determine design parameters such as timing, raise height and loads. During the analysis phase the initial design concept underwent several changes that were vital to it working the way that was intended. The occupant simulation analysis showed a potential reduction of the lower extremity injury measures by as much as 80% for unbelted occupants. The work is fully described in SAE paper 960503. A world-wide patent application for the device was filed by Breed Technologies, Inc. in 1995 and a US patent was issued in 1997 under number 5,695,242.
This image shows the SCRS (on the right) in comparison to a conventional restraint system (on the left). The SCRS effectively lifts the feet off the toe board and limits the forward travel of the lower torso, reducing the interaction of the knees with the instrument panel.
The OSS was successfully implemented in the Jaguar XK8 of Model Year 2001 and has since found its way into several other platforms.