Production of tubular structures

Claim 1

THE METHOD OF FORMING A ROLLED METAL STRIP OF LAMINATE MATERIAL CAPABLE OF BEING SEPARATED LONGITUDINALLY ALONG INTERNAL WEAKNESSES TO FORM NARROWER STRIPS EACH CAPABLE OF OPENING INTO A TUBULAR BODY, WHICH COMPRISES PREPARING A PLURALITY OF FLATTENED TUBES OF INTEGRAL METAL, EACH HAVING PLANE PORTIONS AT ITS EDGES AND AN INTERNAL CHANNEL ALONG ITS LENGTH, PLACING THE TUBES BETWEEN TWO METAL SLABS WITH THE PLANE PORTIONS HAVING A THIN LAYER OF ANTIWELDING MATERIAL BETWEEN EACH TWO ADJACENT TUBES, AT LEAST ONE OF THE SLABS HAVING LONGITUDINAL EXTERNAL GROOVES IN ITS ROLL-CONTACTING SURFACE, SAID GROOVES EACH BEING LOCATED SUBSTANTIALLY OPPOSITE A SAID PLANE EDGE PORTION OF A TUBE WHEN THE METAL PORTIONS AND TUBES ARE PRESSED TOGETHER, PROVIDING BETWEEN THE SLABS METAL PORTIONS SUBSTANTIALLY OF THE THICKNESS OF THE TUBES AND LOCATED LATERALLY OUTSIDE THE LATERALLY OUTERMOST TUBES, PRESSING THE SAID METAL PORTIONS TOWARD ONE ANOTHER IN THE LATERAL DIRECTION AND AGAINST SAID LATERALLY OUTERMOST TUBES AND THEREWITH EFFECTING ABUTMENT OF THE METAL PORTIONS AND TUBES AT THEIR ADJACENT EDGES AS A GROUP EXTENDING IN THE LATERAL DIRECTION ACROSS THE SLABS, EDGE-WELDING THE TUBES, METAL PORTIONS AND SLABS TOGETHER AND SEALING THE CHANNELS AT ONE END, INSERTING ANTIWELDING MATERIAL INTO EACH CHANNEL, AND SUBJECTING THE ASSEMBLY TO A SCHEDULE OF HEATING AND ROLLING OPERATIONS THEREBY TO EFFECT ROLL-BONDING OF THE SLABS, METAL PORTIONS AND TUBES AND THE REDUCTION OF THE ASSEMBLY TO A STRIP HAVING AT ITS SURFACE LAMINATIONS OF METAL SEPARATED BY THE RESIDUES OF THE ANTIWELDING MATERIAL WITH THE LAMINATIONS CONNECTED AT THE EDGES OF EACH SAID RESIDUE BY INTEGRATING METAL AND HAVING LONGITUDINAL INTERNAL WEAKNESSES LOCATED WITHIN SAID INTEGRATING METAL, AND WHEREBY TO CAUSE THE METAL OF THE SLAB TO FLOW LATERALLY FOR BRINGING THE GROOVE WALLS TOGETHER AND TO ESSENTIAL ABUTMENT AND TO FORM A STRIP HAVING SMOOTH ROLL-ENGAGED SURFACES WITH A WEAKNESS OF THE ABUTTING GROOVE WALLS IN SUBSTANTIAL ALIGNMENT WITH THE ROLLED RESIDUE OF THE LAYER OF ANTIWELDING MATERIAL ORIGINALLY PRESENT AT THE SAID PLANE EDGE PORTIONS.

Claim 2

THE METHOD OF FORMING A ROLLED METAL STRIP OF LAMINATE MATERIAL CAPABLE OF BEING SEPARATED LONGITUDINALLY ALONG INTERNAL WEAKNESSES TO FORM NARROWER STRIPS EACH CAPABLE OF OPENING INTO A TUBULAR BODY, WHICH COMPRISES PREPARING A PLURALITY OF FLATTENED TUBES OF INTEGRAL METAL, EACH HAVING PLANE PORTIONS AT ITS EDGES AND AN INTERNAL CHANNEL ALONG ITS LENGTH, PLACING THE TUBES BETWEEN TWO METAL SLABS WITH THE PLANE PORTIONS HAVING A THIN LAYER OF ANTIWELDING MATERIAL BETWEEN EACH TWO ADJACENT TUBES, AT LEAST ONE OF THE SLABS HAVING LONGITUDINAL EXTERNAL GROOVES IN ITS ROLL-CONTACTING SURFACE, SAID GROOVES EACH BEING LOCATED SUBSTANTIALLY OPPOSITE A SAID PLANE EDGE PORTION OF A TUBE WHEN THE METAL PORTIONS AND TUBES ARE PRESSED TOGETHER, PROVIDING BETWEEN THE SLABS METAL PORTIONS SUBSTANTIALLY OF THE THICKNESS OF THE TUBES AND LOCATED LATERALLY OUTSIDE THE LATERALLY OUTERMOST TUBES, PRESSING THE SAID METAL PORTIONS TOWARD ONE ANOTHER IN THE LATERAL DIRECTION AND AGAINST SAID LATERALLY OUTERMOST TUBES AND THEREWITH EFFECTING ABUTMENT OF THE METAL PORTIONS AND TUBES AT THEIR ADJACENT EDGES AS A GROUP EXTENDING IN THE LATERAL DIRECTION ACROSS THE SLABS, EDGE-WELDING THE TUBES, METAL PORTIONS AND SLABS TOGETHER AND SEALING THE CHANNELS AT ONE END, INSERTING ANTIWELDING MATERIAL INTO EACH CHANNEL, AND SUBJECTING THE ASSEMBLY TO A SCHEDULE OF HEATING AND ROLLING OPERATIONS THEREBY TO EFFECT ROLL-BONDING OF THE SLABS, METAL PORTIONS AND TUBES AND THE REDUCTION OF THE ASSEMBLY TO A STRIP HAVING AT ITS SURFACE LAMINATIONS OF METAL SEPARATED BY THE RESIDUES OF THE ANTIWELDING MATERIAL WITH THE LAMINATIONS CONNECTED AT THE EDGES OF EACH SAID RESIDUE BY INTEGRATING METAL AND HAVING LONGITUDINAL INTERNAL WEAKNESSES LOCATED WITHIN SAID INTEGRATING METAL, AND WHEREBY TO CAUSE THE METAL OF THE SLAB TO FLOW LATERALLY FOR BRINGING THE GROOVE WALLS TOGETHER AND TO ESSENTIAL ABUTMENT AND TO FORM A STRIP HAVING SMOOTH ROLL-ENGAGED SURFACES WITH A WEAKNESS OF THE ABUTTING GROOVE WALLS IN SUBSTANTIAL ALIGNMENT WITH THE ROLLED RESIDUE OF THE LAYER OF ANTIWELDING MATERIAL ORIGINALLY PRESENT AT THE SAID PLANE EDGE PORTIONS.