System for seat-actuated head rest extension and retraction

Abstract

A head rest system for an automotive vehicle seat movable between an extended position when the seat back of the vehicle seat is in its upright position and a retracted position when the seat back is in its lowered position. The system includes a seat base, a seat back pivotably attached to the seat base, a head rest movably attached to the seat back by a head rest attachment assembly, and a head rest movement balancing portion. The head rest attachment assembly includes a fixed portion attached to the seat back and a movable portion. The fixed portion includes a spool assembly. The movable portion includes a pair of spaced apart posts attached to the underside of the head rest and a latching assembly. The spaced apart posts are slidably attached to the fixed portion. The head rest movement balancing portion includes a pair of spaced apart constant force springs. Each of the springs has a spool attachment end and a latching assembly attachment end. A cable is provided. One end of the cable is operatively associated with the latching assembly and at the other end is attached to the seat base. A series of pulleys restrain the cable and guide its operation. The disclosed system fixes the head rest at the required height, prevents the passenger from adjusting the head rest when the seat is in an occupiable position, and retracts the head rest automatically when the seat back is folded thereby providing sufficient clearances.