OPEN SHAPING GROOVED PASS OF ROLLS OF MILL FOR ELECTRICALLY WELDING TUBES Russian patent published in 2003 - IPC

FIELD: plastic metal working, namely manufacture of thin-wall electrically welded straight-seam tubes. SUBSTANCE: open shaping roll grooved pass is formed by means of upper and lower rolls mounted with mutual gap S and having diameters variable along width of symmetrical grooved pass and curvilinear generatrices with different curvature radiuses of barrel of upper roll. Small radius r is equal to inner radius of shaped tube. Lower roll has in mean portion of its barrel cylindrical turning and curvilinear generatrices with radius r+S on ends of barrel. Width of turning is equal to distance between joining points of different-radius arcs of generatrix of upper roll. Distance from bottom of turning until barrel of upper roll along mean line of grooved pass is equal to S + (8 - 10)mm. Diameters of lower roll in planes passing through mean points of its curvilinear generatrices are equal to diameter of upper roll along mean line of grooved pass. EFFECT: enhanced wear resistance of rough shaping rolls of mill, lowered probability for damaging rolls, lowered labor consumption of process. 1 dwg, 1 ex