Reversing tool for well pipes

Claim 1

A WRENCH INSERTABLE IN A PIPE STRING FOR UNSCREWING OR TIGHTENING THREADED CONNECTIONS BETWEEN ADJACENT SECTIONS OF THE PIPE STRING, COMPRISING, (A) A MANDREL, (B) MEANS CARRIED BY THE MANDREL FOR CONNECTING THE SAME TO A SOURCE OF TORSIONAL FORCE, (C) LONGITUDINALLY SPACED SUBSTANTIALLY IDENTICAL PIPEGRIPPING UNITS DISPOSED ON THE MANDREL IN POSITION TO ENGAGE SECTIONS OF A PIPE STRING ON OPPOSITE SIDES OF A THREADED CONNECTION BETWEEN SAID SECTIONS, (D) EACH OF SAID UNITS INCLUDING PIPE GRIPPING ELEMENTS OPERABLE IN RESPONSE TO A ROTATIONAL FORCE TO TORSIONALLY GRIP SAID PIPE SECTIONS, AND (E) REVERSING GEAR MEANS MOUNTED ON THE MANDREL BETWEEN THE UNITS AND OPERABLY CONNECTED TO THE MANDREL AND BOTH GRIPPING UNITS, (F) SAID GEAR MEANS BEING CONSTRUCTED AND ARRANGED TO BE OPERABLE ROTATION OF SAID MANDREL IN THE CLOCKWISE DIRECTION TO SIMULTANEOUSLY TRANSMIT OPPOSED ROTATIONAL FORCES TO THE RESPECTIVE GRIPPING UNITS.