US Patent 7367628 Armrest that will not produce noise during adjustment

An armrest includes an armrest support having a locking seat formed with a plurality of locking grooves, a sliding seat movably mounted on the locking seat, and a push button movably mounted on the sliding seat and having a first end formed with a locking portion detachably locked in one of the locking grooves and a second end formed with a push portion. Thus, the locking portion of the push button is detached from the respective locking groove of the locking seat when the sliding seat is movable relative to the locking seat so that the sliding seat will not rub the locking seat during movement of the sliding seat, thereby preventing from producing a noise during adjustment of the armrest.