Patent ID: 8192331

Claim:
A device for adjusting the prestress of one or more elastic elements around a predetermined tension or position, comprising: a connection portion being connected with the one or more elastic elements, a mechanic adjustment unit being connected with the connection portion for a connection in parallel with the one or more elastic elements to preadjust a value of the predetermined tension; wherein said mechanic adjustment unit comprises: a movable portion engaging the connection portion, where the connection portion is located between the one or more elastic elements and the mechanic adjustment unit, and a force exerting element being attached at said movable portion; wherein the mechanic adjustment unit is in an unstable equilibrium position at said predetermined tension or position, a movement of the movable portion being such that the force exerting element adds an adjustment or compensation force upon deviation of the predetermined tension or position of the one or more elastic elements; wherein the force exerting element is a torque exerting element, and wherein the torque exerting element comprises a further elastic element having two end portions, wherein the further elastic element is attached with one end portion at said movable portion, another end portion of the further elastic element being fixedly attached.