| 摘要 |
<p>Machine enabling to apply a high rotation torque to pipes connected end to end in order to lock them at the end of the screwing or to unlock them at the beginning of the unscrewing. Each tong of the machine comprises two fixed jaws (76) applied to the extremity of a pipe and two clamping jaws (76) which are rotatingly mounted about a vertical axis of the tong and actuated by a hydraulic jack (64) one clamping jaw being self-locking for one rotation direction of the tong about the axis of the pipe, and the other clamping jaw being self-locking in the opposite rotation direction. The invention may be particularly applied to the assembly and disassembly of drill pipe strings.</p> |
