| 摘要 |
PURPOSE:To prevent damage of a leading thread and to reduce abrasion of a drum itself by disposing arbitrary plural concave and convex portions extending obliquely with respect to the peripheral direction in the peripheral concave groove of the drum. CONSTITUTION:A drum 1 formed by a cylindrical stainless steel plate has increasing in diameter portions 1a at both side opening edges thereof and a peripheral coconcave groove 1b formed at the central part of the cylinder for reeling off a leading thread 2. The peripheral concave groove is provided with arbitrary plural concave and convex portions 1c parallel to each other, which are formed obliquely with respect to the peripheral direction by spinning. The boundary surface between the increasing in diameter portions 1a and the peripheral concave groove 1b is a curved surface, and round plates 3, 3 are mounted opposite to the opening edges of the increasing in diameter portions. In this arrangement, the leading thread 2 is brought into contact with plural concave and convex portions 1c of the drum 1 obliquely with respect to the peripheral direction of the peripheral concave groove 1b by an ocean current and motion of a ship, whereby the leading thread 2 is kept from closely adhering to the drum 1, but brought into point contact with the top portions of the concave and convex portions to prevent abrasion of the drum 1 and breakage of the leading thread 2 to the utmost. |
