| 摘要 |
The present invention concerns a down-the-hole drill that is driven via a drill string by a flow of fluid, comprising a housing with an impact hammer, the impact hammer being arranged with a drill bit mounted in a driver chuck, a hammer piston with a piston surface arranged to impact onto the neck of the drill bit, and a valve to control the hammer piston backwards and forwards, whereby the valve alternately places under pressure and removes the pressure from a pressure chamber that drives the hammer piston forwards when placed under pressure, the housing further comprising a fluid-driven rotation motor of vane motor type comprising pressure chambers with vanes that rotate the drill bit when placed under pressure. The flow of fluid is led into the housing through a flow distributor and is distributed onwards between the pressure chamber of the rotation motor and the pressure chamber of the hammer piston. |
