Sail board has hollow body contg. insert - having closed chambers formed by interconnected vertical walls e.g. as plastic injection moulding

摘要

The sail board has a long hollow body containing an insert which consists of closed chambers formed by interconnected vertical walls. The insert may be a plastic injection moulding or may consist of a number of segments. The chambers may have a round or polygonal cross-section. The chamber walls may have different thicknesses to obtain the required stability. The insert may be arranged in part or parts of the hollow body only and is pref. secured therein. One or both inner walls of the body may be roughened or provided with conical projections.