Abstract: A system for supporting a seat-pan on a chair and for providing movement to an armrest on the chair. The system includes a mounting assembly with an upper rail having a front portion, a mid portion and a rear portion, and a lower rail having a front portion, a mid-portion and a rear portion. The upper rail is pivotally connected to the lower rail in a manner which allows g generally parallel motion of the rails relative to one another. An armrest support is pivotally attached to the mounting assembly, and includes a linkage for indexing movements of the armrest support relative to motion of the position of the upper rail relative to lower rail, so that motion of the upper rail relative to the lower rail produces a corresponding tilt of the armrest support.

Abstract: The present design is of a variable posture component system seating device, also called a work chair, which integrates user selectable and adjustable components. The components consist generally of a short base, a long base, height adjustment mechanisms, a seat adjustment mechanism, a seat assembly, right and left arm rest assemblies, an abdominal rest assembly, a back rest assembly, a head rest assembly, a knee/leg rest assembly, a keyboard desk assembly, an auxiliary desk assembly, a horizontal work surface assembly, and a variety of interconnecting hardware. Numerous improvements to a variable posture work chair are incorporated into the design, which can benefit workers subjected to extended periods of immobilization as well as the infirm and the injured. Fore and aft support from a single seated position is provided over the entire range of leaning normally associated with human sitting.