| 摘要 |
PURPOSE: A bit holder and a base for the same are provided to secure stable support against a large load generated in excavation. CONSTITUTION: A bit holder(20) comprises an insertion protrusion(21) and a fixing protrusion(25). The fixing protrusion includes a bit receiving part(26) and a supporting part. The supporting part includes two support surfaces(29) that are at a fixed angle and arranged on both sides of a crossing center plane extended in the longitudinal direction of the insertion protrusion. |
