| 摘要 |
PURPOSE:To drill a hole in both slightly different size and accurate bore diameter with a single tool in a drilling tool of drill or the like, by dividing the point end of its cutting edge into two parts and adjusting distances of the divided part from the center of its axial line. CONSTITUTION:The point end side of a drilling tool main body 1a of drill or the like is divided into two parts by a slit 6 along its axial line, and its divided two point end parts 1b, 1c of the tool main body are resiliently deformed by a pre- loading means like a screw 8 to adjust a cutting edge outside diameter. In this way, many kinds of holes with a different diameter from each other can be drilled by a single tool, further a hole diameter as preset can be obtained by adjustment even for a change of the drilling work condition. |
