| 摘要 |
A drill bit assembly for a rotary drill having a source of fluid under pressure and three bearing mounted rotary cutting cones for drilling into relatively hard material comprises an elongated housing with a first end adapted for engagement with the drill and a second end including the cutting cones or tools for engagement with the material to be drilled. A plenum chamber is provided within the housing for receiving pressurized fluid and for dividing the pressurized fluid into three portions. A first portion of the pressurized fluid is directed downwardly for impringement upon the material being drilled to pick up and remove dust and cuttings from the vicinity of the cutting cones. A second flow of the pressurized fluid is directed upwardly to remove the dust and cutting cones from the drill hole. The third flow of fluid is directed through the cutting cone bearings to cool the bearings during the drilling operation. Storage means is also provided within the housing for receiving and storing a supply of lubricating fluid, the lubricating fluid flowing through a distribution conduit to the cutting cone bearings for lubrication thereof. |
