Abstract: A chair control for adjustment of the rest position of a resiliently pivotable chair back, and of the degree of resiliency of the connection of the chair back to the chair frame. A spring brace is mounted on the frame beneath the seat and provides an aperture. A rod assembly connected to the chair back at a universal joint has its remote and extending through the aperture, the rod assembly being slidable through the aperture. A spring tension handwheel concentric with the rod assembly is disposed between the spring brace and the universal joint, and is internally threaded for axially adjustable connection to the rod assembly. A spring retainer is provided on the face of the spring brace nearest the universal joint, and has an aperture corresponding with the spring brace aperture. A compression spring concentric with the rod assembly is confined between the spring retainer and the spring tension handwheel.

Abstract: A locking hinge joint includes a pair of spaced pivot supports such as a bracket of U-cross-section, a hinge member mounted for swinging movement between the supports, and a reciprocable lock mounted on the supports slidable parallel to the swing axis to and from a position in which it positively locks the hinge member against swinging. Two hinge members mounted on a single bracket can be locked simultaneously.

Abstract: Limit stop means for limiting vertical height adjustment of a swivel chair support comprising a spindle, a fixture on one end of the spindle for connection to a chair seat, the upper end of the spindle threaded and having a load supporting adjustment nut thereon, and a keyway along the threaded portion of the spindle terminating below the nut at a position spaced from the lower end of the spindle, the limit stop means comprising a resiliently deformable split ring washer having a key extending inwardly therefrom adapted by deformation for assembly with said chair support over the spindle to a position between said nut and the lower end of the keyway with said key in said keyway and separate retainer means for restraining said washer against deformation.