Continuous strip reduction cold mill

A continuous cold reduction mill for metal strip comprising

• a plurality of uncoilers,
• a metal strip handling means for alternatively taking metal strip from each uncoiler,
• welding means for welding the trailing end of metal strip running through the cold reduction mill to the leading end of metal strip coming off an uncoiler,
• metal strip storage means following the welding means in the direction of strip movement for accumulating under high speed strip handling tension a length of running metal strip which can be continuously fed into the mill while a weld is being made,
• a mill stand having a center line relative to metal strip movement through the mill stand and including a pair of work rolls for exerting cold reduction pressure on metal strip passing between them,
• drag generator means,
• a metal strip back tensioning unit ahead of the mill stand relative to strip movement, the back tensioning unit including a plurality of successive strip engaging rolls, at least one of the strip engaging rolls being operatively connected to the drag generator means,
• means for conveying the metal strip from the strip storage means to the metal strip entrance side of the back tensioning unit while maintaining the metal strip between the strip storage system and the entrance side of the back tensioning unit under an entrance tension of the magnitude of the tension in the strip storage system,
• means including the drag generator associated with the back tensioning unit for multiplying the tension on the metal strip entering the back tensioning unit to obtain a metal elongating back tension on the metal strip leaving the back tensioning unit and entering the mill stand,
• pivoting means supporting the back tensioning unit for limited pivotal movement around a vertical axis,
• power means for pivotally moving the back tensioning unit about the vertical axis,
• means between the back tensioning unit and the mill stand for indicating the location of the center line of the metal strip relative to the center line of the mill stand, and
• means actuated by the last claimed means for activating the power means when the center of the metal strip tends to depart from the center line of the mill stand to cause the power means to pivotally move the back tensioning unit in the direction which will cause the center line of the metal strip to be maintained substantially on the center line of the mill stand.