| 摘要 |
An improved single-boom sailing rig for sailboards, and methods of use. A curved, rotatable boom (100) is provided with a forward end set at a slight angle with respect to the chord, with a separately-rotatable camber control (110) located in the forward end within reach of the sailor's forward hand, for controlling sail curvature with sails (18 and 19) filled and drawing. A finger-operated mast clamp (120) connects boom (100) to mast (13) and provides pivot pin (126) as a bearing onto which the boom (100) may be pushed during assembly. A boom extension (130) is provided with an eccentric locking mechanism for matching boom length to various sail sizes. An alternative extension (230) is locked by insertion of a pin (233) through any of a series of holes (234). Boom extensions (130 and 230) are provided with a sand-proof aft boom bearing assembly (140) having an aft pivot pin (141) which is pushed into plug (145) during assembly, to connect the clews of sail components (18 and 19). A resilient line (149) and a wingscrew (153) provide length and differential sail stretch matching adjustments for sail components (18 and 19), to prevent air leaks between flap (21) of upper sail component (18) and head (22) of lower sail component (19). Sand is excluded from entering camber control (110) and extension (130) by compression of heat-shrink tubes (119 and 139) against wiping rings (118 and 132). In a variation using low-stretch composite sail materials, or radially-cut sails, the wingscrew (153) is eliminated and clew plates (150 and 155) may be replaced by grommets. The sailor matches the length of boom (100) to that of the sail of his choice by moving extension (130 or 230) in or out of boom end (103) and locking it in place. With the sail full and drawing, the sailor may change sail curvature by rotating camber control (110) with his forward hand. |
