| 摘要 |
PURPOSE:To solve a problem for a fine slippage between a key and a groove by providing shallow recessed and protruding parts vertically parallel to each other on the vertical surfaces or lateral surfaces of the key itself. CONSTITUTION:A bar sunk key 1 having a square section has a square sectional area slightly larger than a key groove provided separately, and an end area smaller than the key groove. The key body 1 has, on the upper surface 2 and lower surface 3, shallow corrugated recessed parts (a) and protruding parts (b) in which the corrugated forms on the upper and lower surfaces are parallel to each other. The key 1 is easy to be fitted to the key groove, when pressed into the key groove for fitting, because the end area of the corrugated form is smaller than the key groove, and it can be fitted with a proper hardness when once fitted due to the expanding and contracting property of metal because the sectional area is larger than the key groove. Further, the corrugated protruding and recessed parts are well fitted to the slight distortion or fine difference in size of the key groove, and the key can be fitted without requiring skill. Since the area making contact with the key groove inner wall is small because of the corrugated protruding and recessed parts on the outer surfaces, the key can be easily released when released from the groove. |
