Patent attributes
An angle-adjusting structure for a backrest of a chair is mounted at a rear side of a butterfly-shaped mounting member of the chair. The angle-adjusting structure includes a main body and a rotating member jointly passed through by a shaft having external teeth. A resilient element is mounted around an end of the shaft. A cover is secured to the main body by threaded fasteners. A pressing member is mounted on the other end of the shaft. By pressing the pressing member inward, the external teeth of the shaft are disengaged from internal teeth of the rotating member, and the rotating member is allowed to rotate freely. When the pressing member is released, the resilient element mounted around the end of the shaft extends outward to re-engage the external teeth of the shaft with the internal teeth of the rotating member, thereby securing the rotating member in place.
