Abstract: The disclosure herein relates to lumbar support adjustment for a chair. More specifically, the disclosure related to a lumbar support adjustment mechanism that moves forward and aft relative to the user.

Abstract: A seating structure employing a thermoplastic flexor defining the flexibility and stiffness of a seatback is provided. The seating structure may comprise a seat portion for supporting a user, a seatback portion for supporting a user, a frame for supporting the seat portion and the seatback portion, one or more base portions extending at an angle from the seatback portion, and one or more thermoplastic flexors affixed to or within the seatback and base portions of the seating structure. The thermoplastic flexor has certain material characteristics which define and limit the deflection and a rebound of the seatback portion relative to the base portion when under load. The seating structure may further comprise one or more anchors securing the seatback portion, base portion, and thermoplastic flexor to the frame.

Abstract: A lumbar support adjustment system for a chair that allows a user to adjust the lumbar support by moving a handle on the side of the chair back. The lumbar support and handle move along separate tracks that diverge from each other as the lumbar support is adjusted upward. To compensate for this divergence, the system includes a linkage with a joint connected to the handle and another joint connected to the lumbar support. As the lumbar support is adjusted, the linkage and joint system accommodates for the divergence of the tracks to continue transmitting force from the handle to adjust the lumbar support.