Patent ID: 7798570

Claim:
An adjustable headrest assembly for a vehicle seat having a seat cushion portion and a seat back portion, the headrest assembly comprising: a fixed headrest portion secured to the seat back portion; a movable headrest portion mounted on the fixed headrest portion at a location adjacent the head of a vehicle occupant; the mounting for the movable headrest portion comprising arcuate, telescoping members, one telescoping member forming a part of the movable headrest portion and the other telescoping member forming a part of the fixed headrest portion; at least one spring between the movable and fixed headrest portions for applying a spring force for adjusting the movable headrest portion in a forward direction relative to the fixed headrest portion; at least one releasable locking element securing the movable headrest portions together against a biasing spring force; and the locking element being released in response to an inertia-force of a vehicle rear impact.