Strong-back clamping system for holding pipe joints during welding

Claim 1

AN INTERNAL CLAMPING MEANS FOR HOLDING THE ENDS OF ADJACENT PIPE SECTIONS IN PRECISE ALIGNMENT FOR GIRTH WELDING, COMPRISING, IN COMBINATION: A PLURALITY OF INDIVIDUAL RADIALLY DISTRIBUTED ELONGATED CLAMPING ELEMENTS EXTENDING LONGITUDINALLY OF THE PIPE SECTIONS, EACH OF SAID CLAMPING ELEMENTS HAVING OPPOSITE ENDS ARRANGED TO SELECTABLY ENGAGE THE INTERNAL SURFACES OF ADJACENT PIPE SECTIONS, AND A CENTRAL OUTWARDLY FACING RELIEVED PORTION; FIRST MOTOR MEANS FOR EXPANDING ONE END OF ALL OF SAID CLAMPING ELEMENTS INTO CONTACT WITH ONE OF SAID PIPE SECTIONS, SECOND MOTOR MEANS FOR EXPANDING THE OPPOSITE ENDS OF ALL OF SAID CLAMPING ELEMENTS INDEPENDENTLY OF THE FIRST ENDS INTO CONTACT WITH THE OTHER OF SAID PIPE SECTIONS, A PLURALITY OF HOLDING SHOES, THIRD MOTOR MEANS FOR EXPANDING SAID SHOES INTO INTERNAL CONTACT WITH ONE OF SAID PIPE SECTIONS, A DISC MEMBER, AND FOURTH MOTOR MEANS CONNECTED TO SAID DISC MEMBER COOPERATIVE WITH SAID THIRD MOTOR MEANS FOR LONGITUDINALLY MOVING SAID DISC MEMBER INTO CONTACT WITH SAID HOLDING SHOES TO THEREBY MOVE ONE OF SAID PIPE SECTIONS INTO PREDETERMINED RELATIONSHIP WITH THE ADJACENT PIPE SECTION PRIOR TO THEREBY OF THE OPPOSITE ENDS OF SAID CLAMPING ELEMENTS INTO CONTACT WITH SAID ADJACENT PIPE SECTION.