Abstract: Method for changing working rolls of a roll stand provided with a roll displacement device located on the first side of the stand moving a roll along a loading axis (C, C?). Each has fastening means at a first end towards the first side and matching fastening means at a second end towards the second side of the stand opposite to the first side. Matching fastening means are on the displacement device. The substitute roll can be placed on either side of the stand. The displacement device operates by pulling when the substitute roll is on the second side simultaneously extracting the roll to be replaced towards the first side and loading the substitute roll from the second side; and, vice versa, by pushing when the substitute roll is on the first side of the stand. The various fastening means and matching fastening means are respectively coupled and decoupled.

Abstract: A method for changing rapidly the working rolls of a roll stand (2) provided with a roll displacement device (10) of the push-pull type, located on the first side of the stand and capable of moving a roll along a loading axis (C, C?) of the stand. Each roll (8, 9, 8?, 9?) is fitted by fastening means (100) at a first end towards the first side of the stand and by matching fastening means (200) at a second end towards the second side of the stand opposite to the first side. Said displacement device (10) is fitted with such matching fastening means (300). The substitute roll (8?, 9?) may be placed on anyone of the two sides of the stand.

Abstract: An expandable cylindrical chuck for a coiler, with at least one restricted position and one expanded position. The chuck has a longitudinal axis (1) and comprises a chuck body (3) with a nose (5) and a rear section (7) a tubular sheath (9), segments (11) movable crosswise with respect to the longitudinal axis (1), a control shaft (15) controlling the longitudinal displacement of the segments (11), closing bars (17) located parallel to the longitudinal axis (1) between and in contact with the segments, a pinching bar (23) and a driving shaft (2). The nose (5) and the rear section (7) of the chuck body (3) each comprise an annular surface (39, 41) ensuring tight contact between the chuck body (3) and the segments (11) and between the closing bars (17) and the pinching bar (23).