Method and apparatus to tension hot strip during coiling

Apparatus to tension hot strip for coiling in a hot strip mill, said hot strip mill including a runout table having spaced apart driven rollers for delivering hot strip from a train of finishing mill stands along a pass line of a runout table to a coiler, said coiler having a driven mandrel for coiling strip thereon and pinch rolls having an operative position to direct the leading end of strip from the said runout table to said coiler and tension the deflected leading end portion of strip during the formation of initial convolutions of coiled strip on said mandrel, said apparatus including:

• a gag roll upstream of said pinch rolls at the runout table for tensioning strip conveyed by the runout table after a trailing strip end emerges from the train of finishing mill stands,
• a pinch roll assembly including a lower pinch roll operative for lifting the strip to the passline after deflection by said gag roll;
• an actuator for moving said gag roll from an inoperative position remote to said passline on the runout table into an operative position wherein strip is deflected from the passline sufficiently to partly wrap about a roll face surface of said gag roll thereby tension the strip during coiling;
• and
• a motor coupled to drive said gag roll while in contact with the strip.

Apparatus to tight wind strip in a hot strip mill, said hot strip mill including a runout table having spaced apart driven rollers for delivering hot strip from a train of finishing mill stands along a passline of a runout table to a coiler, said coiler having driven mandrel for coiling strip thereon and pinch rolls having an operative position to deflect a leading end of strip from the passline of said runout table to said coiler and tension a leading portion of strip during the formation of initial convolutions of strip on said mandrel, said apparatus including:

• a gag roll proximate said pinch rolls at the end of the runout table for tensioning strip conveyed by the runout table after a trailing strip end emerges from the train of finishing mill stands;
• an actuator for moving said gag roll from an inoperative position remote to said passline on the runout table into an operative position wherein said gag roll engages and deflects the strip from the passline sufficiently to partly wrap strip about a roll face surface of said gag roll thereby tensioning for tight winding the strip during coiling;
• and
• a motor coupled to drive said gag roll while in contact with the strip.

A method for coiling hot strip delivered from a train of finishing mill stands along a passline of a runout table to a coiler, said method including the steps of:

• deflecting a leading end of hot strip by a pinch roll assembly while advanced along the passline to the coiler;
• creating a first strip tension zone between said pinch roll assembly and a coiler mandrel of said coiler;
• creating a second strip tension zone between the coiler mandrel and a gag roll, said second strip tension zone being formed by deflecting the strip relative to the pass line by engagement with the gag roll;
• driving said gag roll about a longitudinal axis to form a synchronized speed relation between a strip engaging surface of the gag roll and the strip advanced along the pass line;
• and
• preventing marking of the strip surface by establishing said synchronized speed relation before contact between the gag roll and the strip.

A strip tensioning and stabilizing apparatus to tightly wind strip delivered from a hot strip finishing mill on a coiler, said apparatus includes:

• a coiler having an entrance along a pass line to receive strip conveyed by spaced apart driven rollers downstream from such a hot strip finishing mill;
• a gag roll proximate the entrance to said coiler for deflecting the strip from the passline between said spaced apart drive rollers and thereby effect tight winding of strip by the coiler;
• and
• a positioner for moving the gag roll from an inoperative position remote to the passline to an operative position intercepting and deflecting the strip from the passline at the entrance to said coiler to tension for tight winding of the strip during coiling.

A strip tensioning and stabilizing apparatus to tightly wind strip delivered from a hot strip finishing mill on a coiler, said apparatus including:

• spaced apart driven rollers for advancing strip along a passline downstream from such a hot strip finishing mill;
• a gag roll for deflecting the strip from the passline between said spaced apart drive rollers, said gag roll comprising spaced apart rollers operatively positioned in an up stream location and a down stream location to one of said spaced apart driven rollers while supporting the strip;
• and
• a positioner for moving the gag roll from an inoperative position remote to the passline to an operative position intercepting and deflecting the strip from the passline to tension the strip during coiling.

A strip tensioning and stabilizing apparatus to tightly wind strip delivered from a hot strip finishing mill on a coiler, said apparatus including:

• spaced apart driven rollers for advancing strip along a passline downstream from such a hot strip finishing mill;
• a gag roll for deflecting the strip from the passline between said spaced apart drive rollers;
• a lower pinch roller for lifting the strip to the passline after deflection by said gag roll;
• and
• a positioner for moving the gag roll from an inoperative position remote to the passline to an operative position intercepting and deflecting the strip from the passline to tension the strip during coiling.

A method for coiling hot strip delivered from a train of finishing mill stands along a passline of a runout table to a coiler, said method including the steps of:

• deflecting a leading end of hot strip by a pinch roll assembly while advanced along the passline to the coiler;
• creating a first strip tension zone between said pinch roll assembly and a coiler mandrel of said coiler;
• creating a second strip tension zone between the coiler mandrel and a gag roll, said second strip tension zone being formed by deflecting the strip relative to the pass line by engagement with the gag roll;
• and
• arranging a further gag roll to support an upper surface of the strip at the passline before deflection of the strip from the passline.