| 摘要 |
The tool (1) shown is a drill which has a generally cylindrical shank (2) for insertion in a tool receiver or holder of a rotary percussive or rotary machine such as a drilling machine (not shown). The shank (2) has a curved surface portion (3) and a flat surface portion (4) of rectangular configuration, the flat surface portion (4) lying between the ends of the shank. …<??>When the shank (1) is inserted in a tool receiver of a rotary percussive machine (not shown), driving elements thereof engage and act on the flat surface (4) to provide driving torque to the tool, which is thereby rotated. |
