摘要 |
An improved method and apparatus for supplying a fluid coolant to a tool designed for drilling a hole in a workpiece, wherein a first coolant flow is supplied under pressure in a pulsating flow to the tip of the drill by a first pump with a second and booster coolant flow being supplied in a pulsating flow and under considerably greater pressure than the first flow. The second fluid flow is initiated in response to the build-up of back pressure to the first fluid flow to thereby flush away chips impacted on the drill causing such back pressure. The second fluid flow is terminated in response to the drop of back pressure to the first fluid flow. |