Browse Publications Technical Papers 1999-01-0632

Counter Balanced Motion (CBM)-Dynamic Seating—New Seat Mechanics to Reduce Occupant Injury and Enhance Comfort 1999-01-0632

The Counter Balanced Motion (CBM) design utilizes the seat cushion as a crash safety restraint. Just as the air bag becomes a cushion to absorb deceleration forces on the upper body, the seat cushion is used to absorb deceleration forces on the lower body.
Crash simulations of the CBM yield a 33 to 70% reduction in injury loads to the chest and legs. This brings applied forces below bone and joint failure loads.
In addition, impact loads applied to the lower leg become negligible by retracing the feet away from the toe pan and Head Injury Criterion values are reduced 13 to 30%.
The appearance and posture alignment of seats equipped with the CBM mechanism are identical to current production seats. Figure 1.
This paper describes the CBM Seat mechanics, design and function. The functional capabilities are verified by three different, independently performed approaches:
  • 1. dynamic analysis, 2. sled tests, and 3. Madymo crash simulations.


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