| 摘要 |
PROBLEM TO BE SOLVED: To mount a coating width cover and a back plate on a box body easily without using screws, thereby increasing workability. SOLUTION: When a coating width cover 2 is placed on the lower end surface of a box body 1 which is of regular polygonal and cylindrical shape so that the centers of them may be met, and both of them are relatively rotated around the central axis, a portion between of the inward end-surfaces of the inward protrusions 13, 13 of engaging leg pieces 12, 12 facing each other of the coating width cover 2 is engaged with chamfers 8, 8 facing each other on the outer surface of the box body 1 via the elastic deformation of the engaging leg piece 12. However, when a back plate 3 is placed on the upper end surface of the box body 1 so that the centers of them are matched met, and both of them are rotated relatively around the center axis, a portion between the inward end-surface of inward protrusions 20, 20 of engaging leg pieces 19, 19 facing each other of the back plate 3 is engaged with chamfers 7, 7 which face each other on the outer surface of the box body 1 via the elastic deformation of the back plate 3. |
