| 摘要 |
PROBLEM TO BE SOLVED: To hold an indicator in an attachable/detachable manner by forming a holding part which is gradually directed inward and upward continuous to a contour portion on a top surface, and to easily attach the paper indicator to the top surface by preventing it from being detached in a natural condition. SOLUTION: An annular holding part 3 is formed on an upper portion of a top surface 7 continuous to a contour 8. The holding part 3 may be provided intermittently on the top surface. A circular recessed portion to fit an indicator is provided in the holding part 3. An inner circumferential surface of the recessed portion is gradually inclined inward so that the diameter of a bottom surface of the recessed portion is slightly larger than the inside diameter of a most projecting location on the inner circumferential surface. The inward inclination is determined so that an indicator 6 can be easily attached/detached to/from the holding part 3, and the indicator 6 is not detached from the holding part 3 in a natural condition, i.e., unless the forcible force is applied thereto from the outside. |
