Making and breaking of couplings between pipe sections in a drilling rig

For making of breaking a coupling between a pipe section (1) and a pipe string (2) projecting from a rotary drilling rig into a bore in the lithosphere, the pipe section (1) is rotated relative to the pipe string (2) by applying a torque up to a make-up or breaking torque. Exertion of said torque generates a reactive torque in an opposite sense of rotation. Rotation induced by a motor (17; 50) is transferred to the pipe string (2) so that said pipe string (2) is rotated as well. The reactive torque is transferred to the pipe string (2) along a path bypassing the motor (17; 50). Thus, the make-up or breaking torque can be exerted without requiring a substantial change of the torque exerted to rotate the pipe string (2) at a constant rotational velocity in order to avoid changes of the rotational velocity of the pipe string (2). A pipe coupling device and a pipe handler for carrying out this method are described as well.