Tube-welding machines

Claim 1

IN A MACHINE FOR MAKING TUBES FROM FLAT SKELP INCLUDING BENDING MEANS FOR HELICALLY SHAPING SKELP INTO TUBE FORMATION AND FIRST DRIVE MEANS CONTINUOUSLY FEEDING SKELP TO SAID BENDING MEANS AT A PREDETERMINABLE CONSTANT SPEED, THE IMPROVEMENT COMPRISING IN COMBINATION (A) A FIRST SUPPORT ROTATABLY HOLDING AN OPERATING SKELP COIL AND A SECOND SUPPORT ROTATABLY HOLDING A SUBSTITUTING RESERVE SKELP COIL; (B) SECOND DRIVE MEANS DRAWING SKELP FROM THE OPERATING COIL IN SUBSTANTIALLY HORIZONTAL DIRECTION AND PUSHING THE SAME TOWARDS THE FIRST DRIVE MEANS; (C) CLAMPING MEANS TEMPORARILY HOLDING IN ADJACENT RELATION THE REAR END OF THE SKELP PAYED OUT BY THE OPERATING COIL AND THE FRONT END OF THE RESERVE COIL, AND BUTT-WELDING MEANS TO CONNECT SAID ENDS WHILE THE SAME ARE CLAMPED, BOTH MEANS LOCATED BETWEEN SAID COIL SUPPORTS AND SAID SECOND DRIVE MEANS; (D) SPEED CONTROL MEANS FOR SAID SECOND DRIVE MEANS ADJUSTABLE TO KEEP THE SPEED THEREOF EVEN WITH THE CONSTANT SPEED OF THE FIRST DRIVE MEANS THEREBY CAUSING THE SKELP TO MOVE EQUABLY AND STRAIGHT BETWEEN SAID DRIVE MEANS; TO INCREASE THE SAID SPEED WHILE THE MOMENTARILY OPERATED COIL IS ABOUT TO BE EXHAUSTED AND THUS CAUSING THE FORWARDLY PUSHED SKELP TO FREELY BEND INTO A SINGLE LOOP BETWEEN SAID TWO DRIVE MEANS, AND TO INACTIVATE SAID SECOND DRIVE MEANS WHILE SAID CLAMPING MEANS AND SAID BUTT-WELDING MEANS ARE OPERATED AND THE PREVIOUSLY ACCUMULATED LOOP IN THE SKELP IS CONSUMED BEING FED BY THE FIRST DRIVE MEANS INTO SAID BENDING MEANS; (E) AND POSITIONING MEANS ALTERNATELY PLACING ONE OF THE SAID SUPPORTS INTO ALIGNMENT WITH SAID SECOND DRIVE MEANS TO BRING A RESERVE COIL INTO OPERATING POSITION RELATIVE THERETO AND TO SAID CLAMPING MEANS AND SAID BUTT-WELDING MEANS.