摘要 |
A height adjusting device for manually locating and automatically locking a movable structure such as a chair backrest at a desired vertical or angular position relative to a fixed structure such as the chair seat. The device comprises two guided and slidably interlocking plates and one lock pin. A first plate is provided with peripheral apertures, a symmetrically disposed first set of hinge members is provided for fixed engagement in said apertures, said first set of hinged members provided with a cylindrical opening for receiving a mating and symmetrically disposed second set of hinge members which are fixedly mounted on the chair backrest. A second plate is mounted on the "J-bar" or "back-upright" of the chair seat and both plates are engaged so as to slide one relative to the other and provide vertical and angular positioning of the chair backrest relative to the chair seat. |