Apparatus for controlling flatness of metal sheet during rolling

An apparatus for controlling the flatness of a metal sheet during rolling comprising:

• two edge-rollers provided at least at one of the entry and the exit sections of rolling mill rolls, said edge-rollers being located symmetrically in the width direction of a metal sheet during rolling substantially in the horizontal direction, respectively closely adjacent to and facing at least one of the upper and the lower surfaces of said metal sheet at the side edge portions thereof, the axial direction of said edge-rollers being perpendicular to the rolling direction of said metal sheet, and said edge-rollers causing a change in the tension distribution in the width direction of said metal sheet, said edge-rollers being tiltable clockwise and counterclockwise and in the vertical direction around the axial center thereof for imparting a desired vertical displacement to the side edge portions of said metal sheet, thereby increasing the draft at said side edge portions of said metal sheet during rolling;
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• a center-roller provided at least at one of the entry and the exit sections of said rolling mill rolls, said center-roller being located between said two edge-rollers, closely adjacent to and facing at least one of the upper and the lower surfaces of said metal sheet at the width center portion of said metal sheet, the axial direction of said center-roller being perpendicular to the rolling direction of said metal sheet and horizontal, said center-roller being vertically movable, and said center-roller causing a change in the tension distribution in the width direction of said metal sheet, by imparting a desired vertical displacement to the width center portion of said metal sheet, thereby increasing the draft at said width center portion of said metal sheet during rolling.

An apparatus for controlling the flatness of a metal sheet during rolling, comprising:

• two edge-rollers provided at least at one of the entry and the exit sections of rolling mill rolls, said edge-rollers being located symmetrically in the width direction of a metal sheet during rolling substantially in the horizontal direction, respectively closely adjacent to and facing one of the upper and the lower surfaces of said metal sheet at the side edge portions thereof, the axial direction of said edge-rollers being perpendicular to the rolling direction of said metal sheet and symmetrically at a given angle of inclination to the horizontal direction, and said edge-rollers causing a change in the tension distribution in the width direction of said metal sheet, said edge-rollers being movable perpendicularly to the rolling direction of said metal sheet and horizontally with said given angle of inclination maintained for imparting a desired vertical displacement to the side edge portions of said metal sheet, thereby increasing the draft at said side edge portions of said metal sheet during rolling;
• and
• a center-roller provided at least at one of the entry and the exit sections of said rolling mill rolls, said center-roller being located between said two edge-rollers, closely adjacent to and facing at least one of the upper and the lower surfaces of said metal sheet at the width center portion of said metal sheet, the axial direction of said center-roller being perpendicular to the rolling direction of said metal sheet and horizontal, said center-roller being vertically movable, and said center-roller causing a change in the tension distribution in the width direction of said metal sheet, by imparting a desired vertical displacement to the width center portion of said metal sheet, thereby increasing the draft at said width center portion of said metal sheet during rolling.