| 摘要 |
PCT No. PCT/CH84/00104 Sec. 371 Date Mar. 1, 1985 Sec. 102(e) Date Mar. 1, 1985 PCT Filed Jun. 25, 1984 PCT Pub. No. WO85/00333 PCT Pub. Date Jan. 31, 1985.The sail rig comprises a quadrangular sail. A mast sleeve is arranged through the sail area from head to the foot and a flexible mast of flat cross section is inserted therein. A wishbone or a single-boom is connected at the fore to the luff clew and at the rear to the aft leech clew. Owing to the curvature or camber of the sail, its periphery is subject to higher tension than the remaining surface. Therefore, even after rigging up, the sail will not only curve horizontally, but also vertically. When exposed to wind, the sail will form a harmonic compound shape having its concave side to windward. The mast connected to the sail by the mast sleeve bends in the same direction as the sail. The tension around the periphery produces a triangulation effect in conjunction with the mast, similar to that of stays, thereby preventing the mast head from deflecting to leeward. The tension forces of the sail acting upon the mast are balanced and negligible. It is thus possible to build a lighter and more flexible mast. The mastless leading edge offers a minimum of air resistance and enhances laminar airflow. A substantial increase in forward thrust and a reduction of side forces are obtained. This sail rig permits a smaller angle of incidence to the wind, offering more upwind pointing and speed potential. The bending of the mast head to windward under wind pressure means that airflow spillage cannot occur at the head of the rig. |
