| 摘要 |
A drilling apparatus for penetrating material includes an elongated rotary tool for boring an aperture in a workpiece by turning about a longitudinal axis and for moving along the longitudinal axis relative to the workpiece during a cutting operation. The tool also includes a cutting head mounted on an end of an elongated, hollow shaft. A fluid circulation system brings a flowable substance temporarily into engagement with the workpiece during the cutting operation. The circulation system forces the flowable substance to flow in a passage defined by an external surface of the shaft and the workpiece toward the cutting head along an entire longitudinal length of the aperture being drilled. The flowable substance exits the aperture through the hollow shaft after flushing material from the cutting head. |
