Rolling mill for metal strip

A rolling mill (1) for a metal strip comprising:

• a holding cage (2) comprising first and second uprights at two ends of the holding cage, each of the first and second uprights including an inside wall with a vertical groove (28);
• an assembly of superimposed rolls with substantially parallel axes, the assembly comprising a lower supporting roll (5), an upper supporting roll (6), a lower working roll (4), and an upper working roll (3), wherein,
• the lower working roll is adjacent the upper working roll, a through-gap being defined between the lower working roll and the upper working roll,
• the lower working roll and the upper working roll are located between the lower supporting roll and the upper supporting roll,
• the upper working roll is in abutment with the upper supporting roll,
• the lower working roll is in abutment with the lower supporting roll;
• bearings borne by chocks (30, 40, 50, 60), the chocks being movable along a direction parallel to a clamping plane,
• one of the bearings borne by a respective one of the chocks (30, 40, 50, 60) mounting each end of the lower supporting roll (6), the upper supporting roll (5), the lower working roll (4), and the upper working roll (3),
• a first set of the chocks (30, 40) supporting the upper and lower working rolls (3, 4), one of the chocks (30) of the first set of chocks (30, 40) having a vertical groove (32);
• plural guides, each guide located between a respective one of the chocks (30, 40, 50, 60) and the holding cage (2), the guides located along the clamping plane, the chocks slideable along the clamping plane;
• a clamp comprising a pair of hydraulic jacks (Vs), a first of the hydraulic jacks in abutment on a first of the chocks supporting the lower supporting roll (6) and a second of the hydraulic jacks in abutment on a second of the chocks supporting the lower supporting roll (6), the hydraulic jacks operative to apply a clamping force between the first and second chocks;
• a clamping system locking the first set of chocks (30, 40) supporting the upper and lower working rolls (3, 4) in relation to the holding cage, along a respective axis of each of the upper and lower working rolls (3, 4), while allowing the first set of chocks (30, 40) to slide along the guides, along the clamping plane,
• the clamping system comprising a movable component (7) received in the groove (28) of the inner wall of one of the first and second uprights of the holding cage (2) and extending lengthwise along the one upright of the holding cage (2) in the groove (28) of the inner wall of the one upright,
• under action of opening and closing movements of the holding cage (2), the movable component (7) slideable along the one upright of the holding cage (2) between i) a first retracted position (P1) in which the upper and lower working rolls are out of the holding cage (2) and ii) a second locking position (P2) in which the first set of the chocks (30, 40) supporting the upper and lower working rolls (3, 4) are locked in relation to the holding cage,
• the movable component (7) comprising a locking end (71), wherein,
• the movable component (7) is operative to transit from the first retracted position (P1) along the axes of the upper and lower working rolls, to the second locking position (P2), locking the first set of chocks (30, 40) to the holding cage,
• when closing the holding cage, an approaching movement of the upper and lower working rolls (3, 4) in relation to the and lower supporting rolls (5, 6) causes a transition from the first retracted position (P1) to the second locking position (P2);
• and
• during opening of the holding cage, a separating movement of the upper and lower working rolls (3, 4) in relation to the upper and lower supporting rolls (5, 6) causes a transition from the second locking position (P2) to the first retracted position (P1),
• the locking end (71), in moving into said second locking position (P2), simultaneously enters and is received in the vertical groove (32) of the one of the chocks (30) the first set of chocks (30, 40) and the vertical groove (28) of the upright of the holding cage (2) to lock the first set of the (30, 40) to the holding cage, and
• the locking end (71), in moving into the first retracted position (P1) is retracted to slide out of the vertical groove (32) of the of the one of the chocks (30) the first set of chocks (30, 40) thereby allowing withdrawal of the upper and lower working rolls (3, 4) out of the holding cage.