| 摘要 |
<p>A cylindrical rod (2) is enclosed within intermediate (3) and exterior (4) sleeves. Connecting mechanisms (5,6) link the rod, the intermediate sleeve and the exterior sleeve. The connecting mechanisms have toothed wheels (11,13,29,31) at each end and helical threading which engages with threads of different pitch on opposing faces. The intermediate sleeve is connected to either the rod or the exterior sleeve electromagnetically (57).</p> |
