| 摘要 |
<p>A coupling arrangement for breaking threaded joints of drill rods or the like (5), in which arrangement a drill rod or tube (5) is clamped by means of jaws fastened to hydraulic cylinders (8a, 8b; 108a, 108b) on both sides of a threaded joint to retain the tube (5) portion on one side unrotatable with respect to a carrier (2) of a drilling unit (1) and to rotate the tube (5) portion on the other side about its axis. To increase the clamping force, pressure raising cylinders (15; 115) are connected to the pressure channel (12; 112) of the pressure cylinders (8a, 8b; 108a, 108b), into which pressure raising cylinders is led pressure fluid under the normal pressure of the hydraulic net at the moment of breaking the thread, under the influence of which pressure fluid the hydraulic pressure of the pressure raising elements (15; 115) rises to be considerably higher than the normal pressure and thus intensifies the pressure effect created by the cylinders (8a, 8b; 108a, 108b).</p> |
