APPARATUS FOR UNSCREWING DRILL PIPE SECTIONS

摘要

Apparatus is described and claimed for unscrewing first and second threaded sections of a drill string from one another. The apparatus has an arm mounted for rotation about a first vertical axis, the arm forming a first recess. A first actuating mechanism is provided for rotating the arm about the first axis. There is an adapter removably mounted on the arm for clamping the first pipe section. A second actuating mechanism is mounted on the arm and is removably connectable to first and second clamping cams of the adapter for rotating between the retracted and clamping positions. The adapter is replaceable in response to being disconnected from the arm and from the second actuating mechanism. A turning mechanism is provided for rotating a second pipe section while a first pipe section is clamped immovably by the arm.