| 摘要 |
PROBLEM TO BE SOLVED: To provide a will key capable of reducing risk of damaging a valve by securing proper operation of the will key, even when using a will key larger than the will key of a proper size, by properly selecting the will key.SOLUTION: A will key 1 comprises a long size rod body-like operation rod 2 and a pair of hooking legs 3 and 4 provided on one end side in the lengthwise direction of this operation rod 2, orthogonal to the axis of this operation rod 2 and provided at an interval in the axial direction, in which a basic graduation 10 having a graduation line 11 arranged at a unit interval based on a metric system and a conversion graduation 20 having a graduation line 21 arranged at an interval of multiplying the ideal ratio of the length of the operation rod 2 and a diameter of a handle to an interval of the graduation line 11 of this basic graduation 10, are marked in parallel over the substantially total length along the axis of the operation rod 2 on a surface of the operation rod 2.SELECTED DRAWING: Figure 1 |
