US Patent 9282825 Lumbar support adjustment mechanisms

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.