Clamping device of a wire element comprising: - a support defining a U-shaped groove; - a body (6,7) mounted movable with respect to the support; - a first rotation shaft fixed to the body (6,7); - a hollow roller mounted rotating around the first rotation shaft, the first rotation shaft defining a first axis of rotation for the roller, the roller having a groove designed to receive a wire element and being provided with a stop mounted fixedly on the roller so that the stop rotates around the first axis of rotation (AA; - the U-shaped groove and the roller defining a ring designed for passage of a wire element having one wall formed by the roller so that sliding of the wire element in the ring causes rotation of the roller; - a clamp fixed to the body (6,7) and having a first contact surface, the clamp being located inside the roller; - at least one member fixed to the roller so as to rotate around the first axis of rotation in an annular volume arranged between the first axis of rotation and the clamp, the at least one member having a second contact surface, the at least one member being mounted movable with respect to the first axis of rotation between a first member position in which a first distance between the first axis of rotation and a distal part of the second contact area is smaller than a second distance between the first axis of rotation and a proximal part of the first contact area and a second member position in which the first distance is larger than the second distance, rotation of the roller generating a centrifugal force designed to move the second contact surface away from the first axis of rotation to increase the value of the first distance so that the second contact surface is in contact with the first contact surface when the speed of rotation of the roller reaches a threshold speed of rotation, the clamp blocking one direction of rotation of the roller when the first contact surface is in contact with the second contact surface; wherein the stop has a fourth contact area arranged in the hollow; wherein, in the second member position, the member is pressing on an inner side wall that delineates the hollow in the roller; wherein the member is mounted rotatable around a second rotation shaft between the first member position and the second member position, the second rotation shaft being mounted fixedly on the roller; clamping device characterized that, in the second member position, a third contact area of the member is pressing on the fourth contact area, the third contact area being arranged opposite the second contact area; in that the member and the second rotation shaft define a functional clearance in a direction perpendicular to the axis of rotation of the roller. - a support defining a U-shaped groove; - a body (6,7) mounted movable with respect to the support; - a first rotation shaft fixed to the body (6,7); - a hollow roller mounted rotating around the first rotation shaft, the first rotation shaft defining a first axis of rotation for the roller, the roller having a groove designed to receive a wire element and being provided with a stop mounted fixedly on the roller so that the stop rotates around the first axis of rotation (AA; - the U-shaped groove and the roller defining a ring designed for passage of a wire element having one wall formed by the roller so that sliding of the wire element in the ring causes rotation of the roller; - a clamp fixed to the body (6,7) and having a first contact surface, the clamp being located inside the roller; - at least one member fixed to the roller so as to rotate around the first axis of rotation in an annular volume arranged between the first axis of rotation and the clamp, the at least one member having a second contact surface, the at least one member being mounted movable with respect to the first axis of rotation between a first member position in which a first distance between the first axis of rotation and a distal part of the second contact area is smaller than a second distance between the first axis of rotation and a proximal part of the first contact area and a second member position in which the first distance is larger than the second distance, rotation of the roller generating a centrifugal force designed to move the second contact surface away from the first axis of rotation to increase the value of the first distance so that the second contact surface is in contact with the first contact surface when the speed of rotation of the roller reaches a threshold speed of rotation, the clamp blocking one direction of rotation of the roller when the first contact surface is in contact with the second contact surface; wherein the stop has a fourth contact area arranged in the hollow; wherein, in the second member position, the member is pressing on an inner side wall that delineates the hollow in the roller; wherein the member is mounted rotatable around a second rotation shaft between the first member position and the second member position, the second rotation shaft being mounted fixedly on the roller; clamping device characterized that, in the second member position, a third contact area of the member is pressing on the fourth contact area, the third contact area being arranged opposite the second contact area; in that the member and the second rotation shaft define a functional clearance in a direction perpendicular to the axis of rotation of the roller.