Abstract: A vehicle seat includes posture enhancing systems to increase occupant comfort. In addition to pelvis support, the seat includes a pivotable thorax and a height adjustment therefor, having a range of adjustment of about 100 mm to accommodate different female and male occupants having different skeletal lengths. The correct positioning of the second pivot point is designed to provide a lumbar curvature which simulates that of a standing occupant. In its most simple form, the seat includes a pelvis support, a thorax pivot mechanism to allow forward movement of the thorax area and reclining of the shoulders and a linear actuator mechanism to allow accurate positioning of this pivot mechanism for the skeletal height for the occupant.

Abstract: A vehicle seat assembly having a seat back which pivots during a rear impact vehicle collision in Such a manner that the upper end of the seat back rotates foreword. The pivoting seat back includes a releasable latch mechanism to hold the seat back frame fixed in a predetermined position about a pivot axis. The latch mechanism is releasable by inertia forces in response to a rear vehicle collision, to release the latch member and free the seat back frame for rotation about the pivot axis.