Three degree-of-freedom pivot assembly, sail-mounted ballast, and sail control system for high speed sailboats

A method for utilizing wind forces to provide motion comprising:

• providing a hull adapted to move across a surface in a first direction;
• rotatably mounting a pivot assembly to the hull, the pivot assembly being adapted to rotate about a vertical axis approximately orthogonal to the surface;
• rotatably mounting a sail to the pivot assembly so that movement of the sail is limited to two degrees of freedom;
• wherein a first degree of freedom of the two degrees of freedom is adapted to allow the sail to pivot along a relative-wind axis approximately orthogonal to the vertical axis, the relative-wind axis being oriented in a direction defined by the rotation of the pivot assembly about the vertical axis;
• wherein a second degree of freedom of the two degrees of freedom is adapted to allow rotation of the sail about a mast axis approximately orthogonal to the relative-wind axis;
• coupling a ballast to the sail to provide a counter balance;
• and
• wherein the ballast is slidably mounted to the sail.

A system for utilizing wind forces to provide motion comprising:

• a hull adapted to move across a surface in a first direction;
• a pivot assembly rotatably mounted to the hull and adapted to rotate about a vertical axis approximately orthogonal to the surface;
• a sail rotatably mounted to the pivot assembly;
• the pivot assembly adapted to limit the sail to two degrees of freedom;
• wherein a first degree of freedom of the two degrees of freedom is adapted to enable the sail to pivot around a relative-wind axis approximately orthogonal to the vertical axis, the relative-wind axis being oriented in a direction defined by the rotation of the pivot assembly about the vertical axis;
• wherein a second degree of freedom of the two degrees of freedom is adapted to enable rotation of the sail about a mast axis approximately orthogonal to the relative-wind axis;
• a ballast coupled to the sail;
• and
• wherein the ballast is slidably mounted to the sail.