| 摘要 |
<p>A sail (3) manoeuvrable through the rotation of a rolling and unrolling structure (1) to which the sail (3) is anchored along an anchorage edge (3A); a sheath (7) surrounds said rolling structure (1) and engages the sail (3) at opposite sides along a coupling line (5) spaced out from the anchorage edge (3A), said sheath (7) and the sail strip between said coupling line and said anchorage edge having such shapings that when the sail (3) is in unrolled condition the sheath (7) stretches out retaining said strip with the end zones non stretched and causing the sail (3) to take a bellying or fat-sail arrangement, while,starting from the beginning of rolling, the sail (3) is called back into the intermediate zone and progressively also into the end zones, thereby assuming a flat-sail arrangement (Fig.1)</p> |
