| 摘要 |
PURPOSE:To effectively prevent abrasion of a stainless drum with a stainless leading thread by disposing arbitrary plural concave and convex portions orthogonally to the peripheral direction in a peripheral concave groove of the drum. CONSTITUTION:A sheet of stainless steel plate is formed into a cylinder and the end portions thereof are welded to form a drum 1. The drum 1 has increasing in diameter portions 1a having R at both side portions thereof, and the central part of the cylinder is provided with a peripheral concave groove 1b for reeling off a leading thread 2 and with arbitrary plural concave and convex portions 1c formed orthogonal to the peripheral direction by spinning. In this arrangement, a lot of concave and convex portions 1c are formed on the peripheral surface of the stainless drum 1 orthogonal to the peripheral direction of the peripheral concave groove 1b, so that the stainless leading thread 2 is kept from closely adhering to the drum peripheral surface 1b, and brought into point contact with the top portions of the concave and convex portions 1c to reduce abrasion of the leading thread 2 and the drum 1. |
