| 摘要 |
<p>The automatic mandrel comprises a plurality of levers (19) for the support of corresponding jaws (16), a sleeve (15) sealingly slideable in the mandrel body and subjected to control means, a plurality of radial sliders (20) which convert the axial movements of the sleeve into gripping and positioning movements of each jaw. Each lever comprises a first spherical portion (190) for the articulation of said lever to the body of the mandrel and a second terminal hemispherical portion (191) for the articulation to the lever of the corresponding control slider. The first spherical portion is axially movable in a cylindrical seat (23) of the mandrel body, and the second hemispherical portion is engaged in a truncated-cone seat (24) of the corresponding slider. The truncated-cone seat (24) acts as an inclined plane to transmit to the terminal portion of the lever (191) a control force having a radial component and an axial component, the first one being adapted to produce a corresponding radial gripping oscillation and the second one being adapted to produce an axial positioning movement of the lever, subsequent to the radial gripping oscillation and limited by a front stop (30).</p> |
