| 摘要 |
PROBLEM TO BE SOLVED: To provide a spanner head attaining ratchet action by a constitution only having a shape without a movable part and preventing removal at ratchet action. SOLUTION: As the spanner head 10 for performing fastening of a bolt by engaging it with a bolt head part 30, an upper jaw abutment part 20 and a lower jaw abutment part 22 are provided at both sides in an axial direction along a depth end direction from an opening end relative to a central point O of the bolt. An upper jaw escaping part 21 is provided on an upper jaw part 14 and a lower jaw escaping part 23 is provided on a lower jaw part 16, thereby, the ratchet action, i.e., turning in an opposite direction to a fastening direction can be attained. Opening width W defined by an upper jaw distal end abutment part 15 and a lower jaw distal end abutment part 17 for forming an opening end of an opening recession part 11 is made narrower than a distance between opposed surfaces of the upper jaw abutment part 20 and the lower jaw abutment part 22 to prevent removal at the ratchet action. COPYRIGHT: (C)2011,JPO&INPIT
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