Patent ID: 8714642

Claim:
A seat for supporting an occupant of a vehicle and absorbing a force between the occupant and the vehicle created by relative movement between the occupant and the vehicle, said seat comprising: a seat bottom; and a seat back extending from said seat bottom; at least one of said seat bottom and said seat back including a first energy absorbing device configured to absorb at least a portion of the force when a magnitude of the force reaches a first magnitude; said one of said seat bottom and said seat back including a second energy absorbing device configured to absorb at least a portion of the force when the magnitude of the force reaches a second magnitude greater than the first magnitude; said second energy absorbing device supporting said first energy absorbing device so that said first energy absorbing device transmits a portion of the force to said second energy absorbing device when the magnitude of the force reaches the second magnitude; and a third energy absorbing device supporting said second energy absorbing device and configured to absorb at least a portion of the force when the force reaches a third magnitude greater than the second magnitude; wherein said third energy absorbing device is configured to plastically deform to absorb at least a portion of the force when the force exceeds the third magnitude.