Active Head Restraint - Description

DESCRIPTION





Active Head Restraint (AHR) units are standard equipment for both front seating positions in this vehicle. On vehicles so equipped, one inertia-activated AHR unit is located atop each front seat back. Outwardly, an inertia-activated AHR appears the same as a non-active head restraint. The mechanical components that articulate the inertia-activated AHR headrest pad are all concealed within the front seat back frame assembly.

At the top of the seat back frame are two stamped steel headrest guide tubes (1). The guide tubes are each inserted through a molded plastic fulcrum bushing (2) installed in the upper seat back frame member and are permanently fixed to a movable stamped steel armature bracket (3) located just below the upper frame member near the top of the seat back. The armature bracket is secured to a stamped steel pivot link (5) at each side that pivots on a screw threaded into a mounting bracket (4) welded to each side member of the seat back frame. The pivot links are each have a spring (6) attached to a lever opposite the armature bracket attachment that is anchored to the seat back frame side member below, which provides the spring-loaded return action of the inertia mechanism.

The upper end of the static lumbar assembly (7) is secured at each side to the base of the armature bracket. Each side of the lower end of the lumbar assembly is engaged in a ramp bracket (8) riveted to the lower seat back frame member. The optional power lumbar assembly (not shown) is secured to the armature bracket at the top and the ramp brackets at the bottom in an identical manner as the standard equipment static lumbar assembly.

The inertia-activated AHR linkage cannot be repaired. If damaged or ineffective, it must be replaced as a unit with a new seat back frame unit. However, following an AHR deployment if no physical damage to the unit has occurred, unlike many other Supplemental Restraint System (SRS) components, the spring-loaded inertia-activated AHR linkage will reset itself for reuse.