Longitudinally welding the end portions of tubular members

Claim 1

IN APPARATUS FOR WELDING TOGETHER THE EDGES OF A LONGITUDINAL GAP IN A TUBULAR METAL MEMBER, THE APPRATUS HAVING A PAIR OF MEANS BETWEEN WHICH THE MEMBER IS ADVANCED WHILE THE GAP IN V-SHAPED FORM BECOMES CLOSED AT ITS APEX AT A WELD POINT BY THE ACTION OF SAID MEANS, MEANS BEING PROVIDED TO CAUSE HIGH FREQUENCY CURRENT TO FLOW ALONG ON THE OPPOSITE EDGES OF THE GAP IN ADVANCE OF THE WELD POINT FOR HEATING THE GAP EDGES TO WELDING TEMPREATURE AT THE WELD POINT; SAID APPARATUS BEING CHARACTERIZED BY THE PROVISION OF ATTACHMENT MEANS ADAPTED TO BE CARRIED AT AND WITHIN AN END OF THE TUBULAR MEMBER AND COMPRISING A PAIR OF CONDUCTIVE PORTIONS ADAPTED TO BE POSITIONED TO ENGAGE THE ENDS OF SAID GAP EDGES AT SAID END OF THE TUBULAR MEMBER AND TO PROVIDE CONDUCTIVE MEANS FORMING PATHS FOR SAID CURRENT FOR EFFECTIVELY EXTENDING SAID PATHS RESPECTIVELY BEYOND SAID END OF SAID TUBING, AND MEANS REMOVABLY INSERTABLE WITHIN SAID END OF THE TUBING AND ATTACHED TO AND SUPPORTING SAID CONDUCTIVE PORTIONS FOR CARRYING SAME WHILE THE TUBING IS ADVANCED THROUGH THE WELDING APPARATUS, SAID LATTER MEANS INCLUDING MEANS FOR CAUSING SAME FIRCTIONALLY TO ENGAGE ON OPPOSITE SIDES OF THE GAP THE INTERIOR SURFACES OF THE TUBULAR MEMBER AND TO RETAIN THE GAP OPEN ADJACENT THE END OF THE TUBULAR MEMBER UNTIL CLOSED AT THE WELD POINT BY SAID FIRST-NAMED MEANS.