| 摘要 |
A protective cylinder (3) for pipe insulation. The protective cylinder (3) is cut at the rear side of the upper part of a folded section of one edge through a predetermined vertical distance 11 from the upper end of a first longitudinal edge. The cut extends obliquely downwardly and outwardly at the front by the same vertical distance 11 along a first guide line (9) obliquely downwardly and outwardly extending from a first radius portion (9a) at the upper end of the one edge, to an outside bent portion, to form thereby a first engagement portion extending along the first guide line. This serves as both a fitting guide and a rotation stopper. The cylindrical member also has a second longitudinal edge cut slightly obliquely outwardly and downwardly at the upper part thereof by a predetermined vertical distance 13 from a second radius portion (10a) at the upper end of the other edge spaced at a horizontal distance 12 from the second longitudinal edge. The cut extends along a second guide line (10b) slightly obliquely outwardly and downwardly from the second radius portion (10a), to form a portion of the second longitudinal edge downwardly spaced by the distance 13 from the upper end with a second engagement portion with a vertical length 14 serving as at least a rotation stopper. |
