| 摘要 |
The deep drilling tool for workpieces includes a drill bit having an orifice with at least one cutting edge, and a hollow drill stem connectable to the drill bit. The interior of the stem is divided by a longitudinal partition in at least two separate passages. One passage communicates with the orifice of the bit whereas the end part of the or each other passage communicates through openings in the wall of the stem with the exterior surface of the tool. The free end of the stem is provided with inlet means for feeding pressure fluid into the or each other passage, whereas the used pressure fluid together with the drilling chips is discharged through the bit orifice and the first-mentioned passage. |
