| 摘要 |
PURPOSE: To lower the risk of looseness in tool tightening and increase tightening strength by situating each chuck jaw ahead of an axis plane passing the guide axis of a guide bore for the chuck jaw and a chuck axis as viewed in the direction of drill chuck rotation for drilling as well as at a higher level as viewed in the axial direction. CONSTITUTION: An adjustment thread 9 coaxial with a chuck axis 5 meshes with a row of teeth 10 formed in each chuck jaw 7 to rotate it. Each chuck jaw 7 has a chuck ridge 13 of such a length as places it in butt contact mainly with a tool shaft. The chuck ridge 13 lies ahead of an axis plane 16 passing a guide axis 4 of a guide bore 3 for the related chuck jaw 7 and the chuck axis 5 as viewed in the direction of drill chuck rotation for drilling or in the direction of an arrow 11, as well as at a higher axial level or on that side of a cone surface 6 defined by the guide axes 4 which faces the bored spindle. |
