Abstract: An anchor structure for electronic devices includes a plurality of bars that are pivotally coupled through a hinged means. At least one of the bars has a housing space formed in a portion of the interior to allow the bars to be swivelable relative to one another. The anchor structure further has a fastening means which has a handle with a bottom end located in the housing space and hinged on a corresponding bar. The hinged portion on the bottom end of the handle runs through the bar and is fastened to a cam. The housing space also holds a slidable brake element corresponding to the cam and a spring to keep the brake element in contact tightly with the cam so that turning of the cam can selectively move the brake element to a position to escape the axle or to another position to form a tight contact with an axle.