| 摘要 |
<p>Device enabling to impart simultaneous rotating and striking motions to the bit of a drilling head, the drive force required for the latter motion being transmitted through liquid distributed through the drill pipes down to the drive elements arranged in the lower drilling head. The drive elemements are comprised of a turbine (16) supplied with said liquid and driving a hydraulic pump (17) which indirectly actuates, through a distributor (35), the hammer (22) which strikes the shank (27) of the bit (2). Said elements being distributed in two chambers sliding one on the top of the other, said sliding motion being used to stop the striking motion when the device is hanging and to start again the striking motion as soon as the device bears at the bottom of the drilling hole. The invention may be used for any deep drilling or for any drilling in rocky ground or even mellow or water-bearing ground.</p> |
