| 摘要 |
PURPOSE: To facilitate a replacing action and avoid a permanent deformation by matching the shape of the opposite recesses of the oval region of a clamping slit with the remarkably curved portion of the ellipse of a key, and setting the distance between the length of the major axis of the ellipse and the length of the minor axis of the ellipse. CONSTITUTION: An oval region is formed from the recesses 13 of clamping surfaces 8, 9, and the radius of curvature of the recesses 13 is made equal to the radius of curvature of the portion penetrated by the major axis (a) of the elliptical cross sectional profile of the slit width expanded projection 4 of a key 1. The portion having a small curvature of the cross sectional profile of the projection 4 of the foot 2 of a key 1 at the angle position of the figure faces the recesses 13, and a gap is formed because the minor axis (b) is shorter than the distance between the recesses 13. When the key 1 is moved in the turning direction 14, the portion penetrated by the major axis (a) of the cross sectional profile of the projection 4 is inserted between the recesses 3, the clamping surfaces 8, 9 are separated, a tool 11 can be extracted from a clamping slit 10, and the projection 4 is engaged with the recesses 13 in a fixed state. |
