摘要 |
The present invention relates to a thread friction locking device (10), especially adapted to be mounted in a thread coupling between tubes for percussive drilling. A frequent problem in a drill tube system of this type is that the threads, if not tightened, have a tendency to unscrew. This happens especially when the drill string of tubes are raised and disconnected from each other when drilling is finished or the drill bit must be exchanged. The thread friction locking device (10) according to the present invention is characterized in that it has a general shape of an annular ring, it has means for distributing flushing medium in axial direction of the device (10) and it is made out of urethane rubber. |