Patent attributes
A vertically adjustable supporting structure that comprises a link member whose bottom and top portions disposed with a lower end and a top end; a lower hinge having at least one shaft pivoted on the lower end of the link member so as to render the link member rotatably pivoted between the two lower frames of the lower hinge; an upper hinge having at least one shaft pivotally connected on the upper end of the link member so as to render the link member rotatably pivoted between the two upper frames of the upper hinge; at least a coupling assembly having one lower axle wheel and one upper axle wheel disposed between the lower end and the upper end of one side of the link member and between the lower frame and upper frame, respectively, and pivoted on the lower hinge and upper hinge, respectively, with a flexible cord engagingly secured between the lower and upper axle wheels; and at least an idle wheel pivoted on one side of the link member and between the lower and upper axle wheels to be interlacing engaged with the flexible cord and to form a coupling movement, such that the coupling assembly transforms the circular movement of the link member into a rotation for compensating displacement difference of two upper frames without affecting their original angle.
