ENERGY ABSORBING SEAT BACK

A vehicle seat in which the side frame members are articulated intermediate their ends and are pivotally mounted on the seat cushion structure. The pivot joints are friction joints that are preloaded to predetermined torsional resistances. The area of the backrest above the upper or articulating pivots provides an impact area adapted under vehicle collision conditions to receive an impact load from a rear seat occupant's head. The area of the backrest between the backrest to cushion pivots and the articulating pivots functions similarly with respect to back seat occupant knee impacts. The friction joints permit rotation of the upper area of the backrest or rotation of the entire backrest relative to the seat cushion, the rotation occurring at a controlled rate as predetermined by the preloading on the pivot joints, thereby controlling the deceleration of the occupant impacting thereagainst.