ROLL FOR LENGTHWISE ROLLING OF TUBES Russian patent published in 1994 - IPC

FIELD: tube production. SUBSTANCE: roll has a barrel with groove, provided by wavy generatrix, having a pitch, equal to 1/2 or 1/3 of the groove perimeter, and also having a central part and descending portions, whose half-wave height is being uniformly lowered from a line of the roll connection up to a line, separating the outlet and the central part of the grooved pass. The generatrix of the roll grooved pass central part is refined by a sine line with wave height, being changed along the groove from 0.4 till 1.2 of the grooved pass ovality. The wave height in a lengthwise cross section of the roll is also being changed according to a sine line with a pitch no more, than 1/2 of a length of biting arc and no less, than six waves heights of the wave. EFFECT: enhanced quality of tube inner surface due to equalizing of metal distribution in a cross section of a deformation zone and due to enhanced condition of biting in the result of increased pulling capability of roll. 1 cl, 2 tbl, 5 dwg