Automotive design often is the end result of the balancing of a vast array of countervailing factors. Components must be practical but appealing, robust but light weight, and inexpensive to produce but complex in performance. Often consumers perceive a design that fails to fulfill both sides of the coin as deficient. This in turn may result in a costly impact on the designers and manufacturers when such perceptions are translated into lagging sales or damaged reputation. This scenario is played out time and time again in the field of noise and vibration control.
The automotive environment is filled with a vast plurality of components to which motion in the hands of the operator is one of their primary functions. Unfortunately, the automotive environment additionally imparts a wide variety of impact and momentum related forces on these same components during routine operation. The vibrations for the vehicle engine and drivetrain in combination with forces transferred from the road upward through the suspension are all eventually imparted to such movable components. Undue vibrations transferred to these components may lead to premature fatigue and may contribute to noise within the automobile interior. This noise, in turn, can have a significant and lasting impression on the vehicle occupants regarding the perceived quality of the automobile as a whole.
Such is the case with automotive head restraints/headrests. These head restraints are commonly mounted to the automotive seatbacks and are provided a range of vertical adjustment so as to be operator adjustable to both comfort and personal configuration. The head restraint posts, however, when subjected to the vibrations and stresses the automotive environment may tend to produce a rattle or other noise within the seatback. The design approach to date has been to counter such noise generation by increasing the stiffness of the head restraint. This increase in restraint, however, in present designs results in an increase in operation and effort. Thus present designs trade one consumer inconvenience for another. This is unsatisfactory. It would be highly desirable to have a design for an automotive seatback and head restraint assembly that minimize the looseness of the head restraint posts without adversely affecting operational efforts.