摘要 |
In this device, the bore of the cylindrical hub has a groove in the shape of an ellipse in which is engaged a radial boss obtained by an upsetting of the material of the end portion of a tubular element inserted in the bore so as to ensure both the axial and rotational connection with the hub. The upsetting is achieved by means of a punch inserted in the end portion of the tubular element and bearing against the extremity of this end portion. |