Patent attributes
A downhole coupling system for joining together two segments of a tool string includes two mandrels, each having an interlocking interface at an end that abuts the adjacent mandrel and to communicate torque from one mandrel to the next. Each of the mandrels includes a threaded exterior surface, with the threaded surfaces have opposing thread directions or differing thread pitches. The coupling includes mating internal threads. A plurality of axial grooves is formed in each of the interior surface of the coupling and the exterior surface of one of the mandrels. A keyed latch ring having a plurality of internal keys and a plurality of external keys is included to engage the axial grooves, thereby rotationally locking the coupling relative to the first mandrel and second mandrel.
