Double boom for surfboard sail - has each boom spar made in halves with flexible link arranged to flex only in vertical direction

摘要

The double boom for a sailboard sail uses the conventional arrangement of curved spars joined at the ends by V-sockets. Each spar is tubular, in two halves (13, 14) with a flexible connector (15). This is pref. a resilient link with metal baseplates (16), screwed into blocks (18, 19) pinned (17) into the tubes. The link pref. embodies extra metal plates (20) arranged parallel to the baseplates for increased shear stiffness and the tube ends are pref. tongued (23) and grooved (22) vertically to prevent lateral flexure. A flexible sleeve (21) covers the entire joint. The link may have a rated breaking point.