Vehicle seat headrest assembly having vertical and longitudinal adjustment

A vehicle seat headrest assembly comprising:

• a pair of vertical supports for extending upwardly from a vehicle seat back in a laterally spaced relationship from each other with respect to the seat back;
• a headrest including a rear headrest portion and a front headrest portion;
• the rear headrest portion being mounted on the seat back by the pair of vertical supports for vertical movement;
• a linkage that supports the front headrest portion on the rear headrest portion for longitudinal movement in forward and rearward directions with respect to the seat back;
• a rack and pinion mechanism of the rear headrest portion including a pair of racks and a pinion meshed with the pair of racks, and the pair of racks being connected to the linkage to control movement of the linkage and hence the longitudinal movement of the front headrest portion on the rear headrest portion;
• a first helical spring locking clamp including a first helical spring that extends around one of the vertical supports and is wound in a direction to permit upward movement of the headrest for adjustment while preventing downward movement of the headrest;
• a second helical spring locking clamp including a second helical spring that is wound around the pinion of the rack and pinion mechanism in a direction to allow its rotation for permitting linkage movement for forward movement of the front headrest portion on the rear headrest portion while preventing its rotation in an opposite direction for linkage movement for rearward movement of the front headrest portion on the rear headrest portion;
• and
• an actuator for releasing the first and second helical spring locking clamps to permit downward movement of the headrest for adjustment and rearward movement of the front headrest portion on the rear headrest portion for adjustment.

A vehicle seat headrest assembly comprising:

• a pair of vertical supports for extending upwardly from a vehicle seat back in a laterally spaced relationship from each other with respect to the seat back;
• a headrest including a rear headrest portion and a front headrest portion;
• the rear headrest portion being mounted on the seat back by the pair of supports for vertical movement;
• a linkage and a rack and pinion mechanism that support the front headrest portion on the rear headrest portion and control longitudinal movement thereof in forward and rearward directions with respect to the seat back;
• a first helical spring locking clamp that permits upward movement of the headrest for adjustment while preventing downward movement of the headrest;
• a second helical spring locking clamp that permits linkage movement and operation of the rack and pinion mechanism for forward movement of the front headrest portion on the rear headrest portion while preventing linkage movement and rack and pinion mechanism operation for rearward movement of the front headrest portion on the rear headrest portion;
• an actuator for releasing the first and second helical spring locking clamps to permit downward movement of the headrest for adjustment and rearward movement of the front headrest portion on the rear headrest portion for adjustment;
• and
• the friction of the headrest, which includes the second helical spring locking clamp controlling the operation of the rack and pinion mechanism, being tuned so the front headrest portion will move forwardly at a predetermined rate of deceleration to provide head support to a vehicle seat occupant.