| 摘要 |
<p>A composite expanding shaft comprising a pneumatic expanding blocking system of a bobbin and a pneumechanic centering system is disclosed, wherein the pneumechanic system comprises at least a movable thrust element operated by a fluid under pressure supplied into an expansion chamber, a first passage way being apt to connect said expansion chamber to an inflation duct of the pneumatic system, and comprising further an obstructing means of said firts passage way, jointly movable with said thrust element of the centering system, apt to keep closed said first passage way for at least a predetermined portion of the thrust element stroke. <IMAGE></p> |
