| 摘要 |
PURPOSE: To provide a chisel and/or an impact drilling tool capable of properly transmitting large torque and being mounted on a tool holder comprising two locking grooves, and free from the defects in locking when it is mounted on a tool holder comprising a single locking groove. CONSTITUTION: A tool to be mounted on a tool holder in a manually-operated tool device for a chisel and/or an impact drill, is provided with a pair of locking grooves 6, 7 formed on a shank 2, in such manner that they are diametrically opposite to one another and closed at their axial ends. The rotary entrainment grooves 8, 9 opened toward a free end of the shank are formed on the shank 2 diametrically opposite to one another. Further to increase the transmittable torque, a longitudinal groove 11 opened toward the free end of the shank 2 is formed in such manner that it extends through and is positioned asymmetrically to the locking groove 7. A shoulder face 7a for axially securing a tool in the tool holder is formed in an region where the longitudinal groove 11 and the locking groove 7 are not overlapped to one another. |
