COLD ROLLING MILL COMPRISING A SIDE-SHIFT SYSTEM

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to French Patent Application No. 2411561, filed October 23, 2024, the entire content of which is incorporated herein by reference in its entirety.

FIELD

The present disclosure relates to the field of cold rolling, and more particularly to six-roll (6-High) or four-roll (4-High) rolling mills with motor-driven work rolls, and more particularly to such reversible rolling mills, namely configured to roll the strip while alternating the running direction of the strip in the rolling mill.

BACKGROUND

A 4-High rolling mill includes, and as illustrated in the diagram (a) of FIG. 10:

two work rolls, respectively distributed under and over the metal strip, the upper work roll bearing according to an upper contact line with the strip according to a widthwise direction of the strip, and the lower roll bearing according to a lower contact line with the strip, according to the widthwise direction of the strip,

two backup rolls, including an upper backup roll bearing against the upper work roll, on the side opposite to the strip by a contact line, and a lower backup roll bearing against the lower work roll on the side opposite to the strip by a contact line.

A 6-High rolling mill includes, and as illustrated in the diagram (b) of FIG. 10:

two work rolls, distributed under and over the metal strip, the upper roll bearing according to an upper contact line with the strip, according to a widthwise direction of the strip, and the lower roll bearing according to a lower contact line with the strip, according to the widthwise direction of the strip,

two backup rolls, including an upper backup roll and a lower backup roll;

two intermediate rolls, including an upper intermediate roll, in contact through a first contact line with the upper backup roll, and in contact through a second contact line with the upper work roll, ad a lower intermediate roll, in contact through a first contact line with the lower backup roll, and in contact through a second contact line with the lower work roll.

In both cases, whether the rolling mill is a 4-High rolling mill or a 6-High rolling mills, hydraulic clamping units exert a clamping force between the upper backup roll and the lower backup roll, tending to approach the axes of rotation of the two backup rolls in order to transmit a clamping force to the work rolls, directly between each backup roll and each work roll, in the case of a 4-High rolling mill, or via the intermediate rolls in the case of a 6-High rolling mill.

A so-called 6-High rolling, so-called laterally supported, is also known as illustrated in the diagram (c), namely a rolling mill that includes the two backup rolls, the two intermediate rolls, the two work rolls, but also and for each work roll, two lateral backup rolls, to the right and to the left of each work roll, bearing through contact lines on both sides of the roll. In such a rolling mill with six laterally backed rolls, the work rolls are typically floating, not directly driven, the motor drive directly driving the intermediate rolls.

A 20-High rolling mill is also known, as illustrated in the diagram (d) of FIG. 10, including, one either side of the strip, an upper group and a lower group.

Each of the upper and lower groups includes:

a work roll, in contact with the strip to be rolled,

two first intermediate rolls, in contact by two bearing lines with the work roll,

three second intermediate rolls, in contact by four bearing lines with the two first intermediate rolls,

four sets of support rollers, in contact according to six bearing lines with the second intermediate rolls.

In such a 20-High rolling mill, the work rolls are not driven in rotation directly, but only via second intermediate rolls.

The present disclosure exclusively covers the 4-High rolling mill according to the diagram (a) or the 6-High rolling mill according to the diagrams (b), namely rolling mills whose work rolls are not laterally supported.

In such a 4-High or 6-High rolling mill, each of the work rolls is pivotably mounted at its guide ends in chocks, each work roll being a body made of machined metal comprising a roll table, typically cylindrical, but also the two guide ends in extension, with smaller diameters than the roll table. The guide ends comprise a first guide end configured to be pivotably mounted in the first chock typically via bearings such as rolling bearings, and a second guide end configured to be pivotably mounted in the second chock, typically via bearings such as rolling bearings.

Such a rolling mills comprises a stand which comprises an inlet window, delimited between two front posts of the stand, and on the opposite side of the stand, two rear posts of the stand.

During maintenance operations, such as the replacement of rolls, the rolls such as the work rolls can be extracted axially, through the inlet window. The motor drive for driving the work rolls is implemented on the other side, namely on the side of the two rear posts of the stand.

In such a rolling mill:

the first chock, at one of the ends of the (lower or upper) work roll, can be guided vertically between the two front posts of the stand, but the position of the chock according to the direction of the strip is blocked by supports on the two front posts,

the second chock, at the other one of the ends of the (lower or upper) work roll, can be guided vertically between the two rear posts of the stand, but the position of the chock according to the direction of the strip is blocked by supports on the two rear posts.

In such a 4-High or 6-High rolling mill, the work rolls are motor-driven, and preferably to directly transmit to the two lower and upper work rolls, respectively rotational torques in contra-rotating directions, in order to assist in the rolling action. Directly motor driving the work rolls is preferred rather than a motor driving the intermediate rolls for a 6-High rolling mill.

An indirect motor drive might cause a slip between the rolls at the origin of a degradation of the surface condition of the roll table, and which allows avoiding a direct motor drive of the work rolls.

In such a 4-High or 6-High rolling mill, vertical forces are applied, during rolling, on the work roll to ensure the reduction of the thickness of the strip by the work roll which is also subjected to the action of horizontal forces.

As illustrated in FIG. 9, there are four main horizontal forces applied on the work roll:

the horizontal component of the clamping force,

the strip tension difference,

the roll force due to the transmission of the torque to the work roll, which should be taken into account only when the work rolls are directly driven by the motor drive,

the horizontal component of the forces exerted by the chocks on the guide ends of the work roll.

The vertical and horizontal forces unbalance the work roll, and cause cambers in the work roll. Under the effect of the vertical component of the forces on each work roll, the work roll cambers according to a vertical component, and under the effect of the horizontal component of the forces, the work roll cambers according to a horizontal component.

The rolling mill may typically comprise an opening/closure mechanism including, at the front and at the rear of the stand, a left cylinder system, interposed between a left one of the front (or respectively rear) posts, and the two chocks of the lower and upper work rolls, on this left side, including a right cylinder system interposed between the other right one of the posts, and the two chocks on the right side.

Each (right or left) cylinder system may be removably coupled to the two chocks of the lower and upper rolls. In general, the deployment of the cylinders according to a vertical direction allows spacing the chocks of the upper roll and of the lower roll apart, in order to open the rolling mill. These cylinders may also be actuated to vertically constrain the guide ends of the work rolls in order to vertically balance the work rolls and thus reduce the vertical component of camber.

For a 4-High or 6-High rolling mill, not laterally supported, the motor torque created by direct drive of the work roll, while the ends of the work roll are blocked by the chocks, typically causes a cambering of the work roll, in a horizontal plane, with a deflection that is maximum between the two ends of the work roll. The deflection is directed in the direction opposite to the running direction of the strip, namely the horizontal component of the camber extends upstream of the strip in the running direction.

In a 4-High or 6-High rolling mill, it is known to balance the horizontal components exerted on the work roll, and thus reduce the horizontal component of the camber by shifting the axis of the work roll according to the running direction of the strip, hereinafter so-called rolling direction. As illustrated in FIG. 9, the axis of the work roll is shifted with respect to the roll bearing on the work roll in the same direction as the running direction of the strip.

For a reversible rolling mill, it is also known to reverse the shift direction change, in case of reversal of the running direction of the strip during rolling.

A first type of a system for shifting the chocks of the work rolls sideways is known from the prior art comprising horizontal hydraulic cylinders, which apply them against a reference surface, namely the shift caused by actuation of the cylinders is typically all or nothing.

Such a prior art is disclosed for example by document JP2790741 or WO2023/073998. Such a shift system allows properly balancing the work rolls when the rolls are not too small to avoid an excessive horizontal deflection.

A second shift system is also known from the prior art based on the use of rectilinear sloped wedges, including first sloped wedges interposed to the left of the chock and the left post, and second sloped wedges interposed to the right of the chock, and the right post, on both sides of the stand.

Each wedge extends lengthwise, parallel to the longitudinal axis of the work roll, and is configured to slip over a wear plate of the post along a firs surface, and along support spacers which bear, on the one hand, on a second inclined surface of the wedge and, on the other hand, on a vertical guide plate, intended for vertical guidance of the vertical cylinder system for opening the stand.

Such an adjustment system allows adjusting the side shift of the chocks, by synchronising the movements of the first wedges and of the second wedges, namely when the first wedges are moved longitudinally according to a direction tending to space apart the chock from the left post, the second wedge is moved longitudinally according to an opposite direction to allow approaching the chock to the right post.

Such a prior art, for example disclosed by document US 4,736,609, has the advantage of allowing for a great progressivity of adjustment. When the ratio of the diameter of the work roll to the width of the strip becomes small typically less than 0.23, the adjustment system with a sloped wedge is accurate enough to properly balance the forces acting on the work rolls, and in order to avoid an excessive horizontal deflection, which is not generally allowed by the prior art based on horizontal cylinders.

According to the observations of the Inventors, such a sloped wedge system comprises, for each rectilinear wedge, a substantial bulk which extends not only lengthwise, according to the length of the sloped wedge, but also lengthwise according to the length of an actuation cylinder which longitudinally extends the wedge, cantilevered outside the stand, according to a direction transverse to the rolling mill, and on both sides of the stand, at the front and at the rear.

Such an adjustment system with a sloped wedge substantially increases the bulk of the rolling mill, beyond the limits of the stand, and in particular on the side of the access window of the rolling mill, to the detriment of maintenance operations.

Another flaw of such a sloped wedge system identified by the Inventors is that its sloped guide surfaces are soiled by rolling impurities in particular rolling oils, and the rolling metal particles, during the operations and therefore requires periodic maintenance.

The present disclosure improves this situation.

SUMMARY

The present disclosure aims to completely or partially improve the situation.

The present disclosure relates to a 4-High or 6-High rolling mill, including a side shift adjustment system configured for implementing a side shift, viewed according to the rolling direction between, on the one hand, an axis of the lower work roll (or respectively of the upper work roll) and, on the other hand, an axis of a roll bearing on the work roll such as a lower (or upper) backup roll.

The present disclosure also relates to a method for rolling a metal strip, ferrous or non-ferrous, implemented by a rolling mill comprising balancing the upper and lower work rolls, through

an upper side shift, between the axis of the upper work roll and the axis of the roll bearing on the work roll,

a lower side shift, between the axis of the lower work roll and the axis of the roll bearing on the work roll.

In an aspect of the disclosure, a 4-High or 6-High cold rolling mill is provided, configured for rolling a metal strip:

a rolling mill stand comprising, at a front side, a first pair of posts and, at a rear side, a second pair of posts,

an upper work roll comprising a roll table configured to come into contact with the upper surface of the metal strip and two guide ends,

a lower work roll comprising a roll table configured to come into contact with the lower surface of the metal strip and two guide ends,

an upper backup roll, configured to transmit a clamping force to the upper work roll, directly according to a contact line between the upper work roll and the upper backup roll, or indirectly via an upper intermediate roll by a first bearing line between the upper backup roll and the upper intermediate roll and a second bearing line between the upper intermediate roll and the upper work roll,

a lower backup roll, configured to transmit a clamping force to the lower work roll, directly according to a contact line between the lower work roll and the lower backup roll, or indirectly via a lower intermediate roll by a first bearing line between the lower backup roll and the lower intermediate roll and a second bearing line between the lower intermediate roll and the lower work roll,

two upper chocks arranged at the two guide ends of the upper work roll, including a first upper chock interposed between the two posts of the first pair of posts, and a second upper chock interposed between the two posts of the second pair of posts,

two lower chocks arranged at the two guide ends of the lower work roll, including a first lower chock interposed between the two posts of the first pair of posts, and a second lower chock interposed between the two posts of the second pair,

a system for adjusting a side shift configured for implementing a side shift, viewed according to the rolling direction between, on the one hand, an axis of the lower work roll or respectively of the upper work roll and, on the other hand, an axis of a roll bearing on the work roll consisting of the lower or upper intermediate roll when the rolling mill is a 6-High rolling mill, and consisting of the lower or upper backup roll when the rolling mill is a 4-High rolling mill,

and where the adjustment system comprising:

a first left pushing mechanism between a left one of the posts of the first pair, on the one hand, and the first upper chock and first lower chock set, on the other hand, configured to exert a pushing force on the first upper chock and first lower chock set to move said set in a first way according to the rolling direction,

a first right pushing mechanism between the other right one of the posts of the first pair, on the one hand, and the first upper chock and the first lower chock, on the other hand, configured to exert a pushing force on the first upper chock and first lower chock set to move said set in a second way according to the rolling direction,

a second left pushing mechanism between a left one of the posts of the second pair, on the one hand, and the second upper chock and second lower chock set, on the other hand, configured to exert a pushing force on the second upper chock and second lower chock set to move said set in the first way according to the rolling direction,

a second right pushing mechanism between the other right one of the posts of the second pair, on the one hand, and the second upper chock and second lower chock set, on the other hand, configured to exert a pushing force on the second upper chock and second lower chock set to move said set in the second way according to the rolling direction.

According to the present disclosure, the first left and right pushing mechanisms, and the second left and right pushing mechanisms comprise all or part of the rotary helical pushing devices, each rotary helical device comprising a first part bearing on one of the posts for the first pair or respectively bearing on one of the posts for the second pair and a second part configured to laterally push the first lower and upper chocks or respectively to respectively push the second lower and upper chocks and wherein the first part and the second part of each rotary helical pushing device are configured to pivot relative to one another, about an axis of rotation under the action of an actuator, the first part and the second part comprising helical guide surfaces arranged around said rotation, bearing on each other, configured to cause a spacing of the second part relative to the first part in the direction of the axis of rotation, upon a relative rotation between the first part and the second part.

The features outlined in the following paragraphs can optionally be implemented independently of one another or in combination with one another:

According to one embodiment, the helical guide surfaces may consist of: - cam surfaces of the first part and of the second part which consist of a first cam and a second cam, or, - respectively inner and outer threads meshing together between the first part and the second part.

According to an embodiment:

the first part is the first cam which comprises a first helical guide surface extending over a first angular portion of the first cam around said axis of rotation and a second guide surface extending over a second angular portion of the first cam,

the second part is the second cam which comprises a third helical guide surface extending over a first angular portion of the second cam and a fourth helical guide surface extending over a second angular portion of the second cam,

and wherein the first helical guide surface and the second helical guide surface of the first cam are configured to cooperate in guidance simultaneously with the third helical guide surface and the fourth helical guide surface of the second cam.

According to an embodiment, the first part and the second part are enclosed within a cowling protecting the helical guide surfaces of the external environment, in particular the cowling comprising a cylindrical wall with an axis coaxial with the axis of rotation of the rotary helical pushing device.

According to an embodiment, the actuators of the rotary helical pushing devices consist of cylinders extending longitudinally according to the height of the posts.

According to an embodiment, all or part of the cylinders are articulated to said second part via a first end of the cylinder, and articulated via a second end to one of the posts via a pivot axis, in particular parallel to the axis of rotation of said rotary helical pushing device.

According to an embodiment, the helical guide surfaces of each rotary helical pushing device are arranged overlapping, in the transverse direction, with the width of one of the posts on which the rotary helical device is bearing, the helical guide surfaces with a diameter D contained in the transverse direction, along the width of the post.

According to an embodiment, the second part has an extension or a lever arm extending outwardly, radially to said second part around the axis of rotation beyond the diameter of the helical guide surfaces, said extension or the lever arm projecting from the post in the transverse direction, the cylinder being articulated by its first end of the hydraulic cylinder on said extension or to the lever arm.

According to an embodiment:

each of the first left pushing mechanism and of the first right pushing mechanism comprises one single pair of first part and second part extending in height, overlapping the height of the first upper chock and first lower chock set,

each of the second left pushing mechanism and of the second right pushing mechanism comprises one single pair of first part and second part extending in height, overlapping the height of the second upper chock and second lower chock set.

According to an embodiment, the rolling mill comprises:

a first left opening/closure mechanism, with a vertical cylinder comprising an upper portion coupled, laterally to the left, to the first upper chock, and a lower portion coupled, laterally to the left, to the first lower chock as well as a hydraulic cylinder configured to space the first lower and upper chocks apart or to bring them together, the first left pushing mechanism interposed between the left post and said first left opening/closure mechanism,

a first right opening/closure mechanism, with a vertical cylinder comprising an upper portion coupled, laterally to the right, to the first upper chock, and a lower portion coupled, laterally to the right, to the first lower chock as well as a hydraulic cylinder configured to space the first lower and upper chocks apart or to bring them together, the first right pushing mechanism interposed between the right post and said first right opening/closure mechanism,

a second left opening/closure mechanism, with a vertical cylinder comprising an upper portion coupled, laterally to the left, to the second upper chock, and a lower portion coupled, laterally to the left, to the second lower chock as well as a hydraulic cylinder configured to space the first chocks apart or to bring them together, the second left pushing mechanism interposed between the left post and said second left opening/closure mechanism,

a second right opening/closure mechanism, with a vertical cylinder comprising an upper portion coupled, laterally to the left, to the second upper chock, and a lower portion coupled, laterally to the left, to the second lower chock as well as a hydraulic cylinder configured to space the first chocks apart or to bring them together, the second left pushing mechanism interposed between the left post and said first right opening/closure mechanism.

According to an embodiment, the upper work roll and the lower work roll comprise transmission shafts coupled to a motor drive for directly driving the work rolls in rotation.

According to a second aspect, the present disclosure relates to a method for rolling a metal strip implemented by a rolling mill according to the present disclosure, comprising:

A. rolling the metal strip by running between the two upper and lower work rolls held pressed on the strip through a hydraulic clamping action between the lower and upper two backup rolls, and by transmission of motor torques to the upper work rolls and to the lower work roll,

B. balancing the upper and lower work rolls, through

an upper side shift between the axis of the upper work roll and the axis of the roll bearing on the work roll,

a lower side shift between the axis of the lower work roll and the axis of the roll bearing on the roll, and wherein the upper side shift and the lower side shift are obtained through a progressive control in real-time of the angular position of the first part with respect to the second part of each rotary helical pushing device to ensure a lateral push of the lower and upper first chocks and of the lower and upper second chocks of the lower and upper work rolls, with backlash compensation.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features, details and advantages will appear upon reading the detailed description hereinafter, and on analysis of the appended drawings, wherein:

FIG. 1 shows a 6-High rolling mill, in perspective view.

FIG. 2 is a sectional view of the rolling mill of FIG. 1, according to a vertical plane passing through the axis of the backup rolls.

FIG. 3 is a front view of the rolling mill, illustrating the chocks of the rolls, including the chocks of the upper work roll and of the lower work roll, as well as a system for adjusting the side shift configured for implementing a side shift, viewed according to the rolling direction between, on the one hand, an axis of the work roll and an axis of a roll bearing on the work roll consisting of the intermediate roll and including a first left pushing mechanism interposed between the left post and the first upper and lower chocks and, on the other hand, a first right pushing mechanism interposed between the right post and the first upper and lower chocks, the first and second pushing mechanisms including a helical pushing device with backlash compensation, the helical pushing devices comprising a first part and a second part rotatably articulated, and actuated relative to one another in rotation by cylinder actuators, the cylinders extending according to the height of the left and right posts on the facade.

FIG. 4 is a rear view of the rolling mill, on the side of the motor drive of the work rolls, illustrating the system for adjusting the side shift on this side, including a second left pushing mechanism interposed between the left post and the second upper and lower chocks and, on the other hand, a second right pushing mechanism, interposed between the right post and the second upper and lower chocks, the first and second pushing mechanisms including a helical pushing device with backlash compensation, the pushing devices comprising a first part and a second part articulated in rotation, by cylinder actuators, the cylinders extending according to the height of the posts at the rear of the stand.

FIG. 5 is a sectional view, according to a vertical plane passing through the axis of rotation, of the right and left helical pushing devices, respectively interposed between the first upper and lower chocks of the work rolls, and the left and right posts.

FIG. 6 is a sectional view, according to a horizontal plane passing through the axis of rotation, of the right and left helical pushing devices, respectively interposed between the first upper and lower chocks of the work rolls, and the left and right posts.

FIG. 7A is a view of a helical pushing device (protective cowling not illustrated), comprising a first part formed by a first cam and a second part formed by a cam, rotatably articulated relative to one another, cooperating with each other by helical guide surfaces.

FIG. 7B is a detail view of the second cam which includes helical guide surfaces, as well as a radial extension forming a lever arm configured to be connected to an actuator.

FIG. 7C is a detail view of the first cam.

FIG. 7D is a detail view of internal guide members, interposed between the first cam and the second cam.

FIG. 7E is a detail view of internal guide members, interposed between the first cam and the second cam.

FIG. 8 is a detail view illustrating the arrangement of the actuator of a helical pushing device, formed by a substantially vertical cylinder, extending along the post on which the cams bear, the cylinder articulated by one end on a radial extension of the second cam, and by another end to the post.

FIG. 9 illustrates:

the forces involved during rolling and applied to a work roll, when this work roll, guided and held by its ends by chocks, receives a motor torque,

a side shift, view in the running direction of the strip, between the axis (of rotation) of the work roll and the axis (of rotation) of the roll bearing on the work roll, the shift performed in the same way as the running way of the strip, configured to balance the work roll, by limiting cambering of the work roll in the horizontal plane..

FIG. 10 schematically illustrate different rolling roll configurations, and in particular:

(a) a 4-High rolling mill configuration, including motor-driven work rolls,

(b) a 6-High rolling mill configuration, comprising motor-driven work rolls,

(c) a so-called laterally-supported 6-High rolling mill configuration, comprising work rolls laterally held by lateral backup rolls, and motor-driven intermediate rolls,

(d) a 20-High rolling mill configuration.

DETAILED DESCRIPTION

The present disclosure relates to a cold rolling mill 1 configured for rolling a metal strip, and in particular a 4-High rolling mill as illustrated in the diagram (a) of FIG. 10, or a 6-High rolling mill, as illustrated in the diagram (b) of FIG. 10.

More particularly, the present disclosure relates to such rolling mills whose work rolls are (directly) driven by a motor drive.

The rolling mill 1 comprises:

a rolling mill stand 2 comprising, at a front side, a first pair of posts M1, M2 and, at a rear side, a second pair of posts M3, M4,

an upper work roll WRS comprising a roll table configured to come into contact with the upper surface of the metal strip and two guide ends,

a lower work roll WRI comprising a roll table configured to come into contact with the lower surface of the metal strip and two guide ends,

an upper backup roll WAS, configured to transmit a clamping force to the upper work roll, directly according to a contact line between the upper work roll and the upper backup roll, in the case where the rolling mill is a 4-High rolling mill, or indirectly via an upper intermediate roll WIS, by a first bearing line between the upper backup roll WAS and the upper intermediate roll WIS and by a second bearing line between the upper intermediate roll WIS and the upper work roll WRS, when the rolling mill is a 6-High rolling mill,

a lower backup roll WAI, configured to transmit a clamping force to the lower work roll WRI, directly according to a contact line between the lower work roll and the lower backup roll, or indirectly via a lower intermediate roll WAI by a first bearing line between the lower backup roll WAS and the lower intermediate roll WII and by a second bearing line between the lower intermediate roll WII and the lower work roll WRI,

two upper chocks arranged at the two guide ends of the upper work roll WRS, including a first upper chock E1S interposed between the two posts M1, M2 of the first pair of posts, and a second upper chock E2S interposed between the two posts M3, M4 of the second pair of posts,

two lower chocks arranged at the two guide ends of the lower work roll, including a first lower chock E1I interposed between the two posts M1, M2 of the first pair of posts, and a second lower chock E2I interposed between the two posts of the second pair M3, M4.

In general:

the upper backup roll WAS comprises a roll table, bearing on the roll table of the upper work roll WRS, in the case of a 4-High rolling mill, or bearing on the roll table of the upper intermediate roll WIS, when the rolling mill is a 6-High rolling mill. The roll table of the upper backup roll WAS is extended by guide ends, which are guided in rotation in two upper chocks EAS. The two upper chocks EAS are received and vertically guided respectively between the two posts M1, M2 of the first pair of posts, on the front side, and between the two posts M3, M4 of the second pair of posts on the rear side of the stand,

the lower backup roll WAI comprises a roll table, bearing on the roll table of the upper work roll WRI, in the case of a 4-High rolling mill, or bearing on the roll table of the lower intermediate roll WII, when the rolling mill is a 6-High rolling mill. The roll table of the lower backup roll WAI is extended by guide ends, which are rotatably guided in two lower chocks EAI. The two lower chocks EAS are received and vertically guided respectively between the two posts M1, M2 of the first pair of posts, on the front side, and between the two posts M3, M4 of the second pair of posts.

In general, the rolling mill comprises a clamping hydraulic system configured to transmit a rolling force (or clamping force), by approaching the support rolls, and in particular hydraulic units configured to bear on the chocks of the backup rolls. The two hydraulic units PT may be arranged at the upper portion of the stand, respectively positioned between the posts M1, M2 of the first pair and the posts M3, M4 of the second pair, to bear on the two upper chocks EAS of the upper backup roll WAS, and as illustrated in the figures. Alternatively, the hydraulic units may be arranged at the lower portion of the stand to act on the lower chocks EAI of the lower backup roll WAI and according to another embodiment (not illustrated).

In general, the 4-High (or 6-High) rolling mill may comprise a system for adjusting the pass-line, configured to adjust the height of the pass-line.

In general, and with reference to FIG. 1, and in the present disclosure, a reference frame X, Y and Z is defined with:

the so-called longitudinal direction X, according to the running direction DL of the strip B between the work rolls, typically horizontal,

the so-called transverse direction Y, perpendicular, extending according to the widthwise direction of the metal strip,

the direction Z, is the vertical direction of the posts of the stand.

In the case of the present disclosure, the backup rolls, the work rolls and possibly the intermediate rolls are directed substantially parallel to the transverse direction Y.

As illustrated in FIGS. 1 or 2, and according to one embodiment, such a system for adjusting the pass-line PST is arranged at the lower portion of the stand, to cooperate with the lower chocks EAI of the lower backup roll WAI, when the hydraulic units are engaged with the upper chocks EAS of the upper backup roll WAS.

The system for adjusting the pass-line comprises one or more rectilinear sloped wedge(s) configured to act on the two chocks EAI of the lower backup roll and change the vertical position of the chocks when the sloped wedge is moved by an actuator. In the case where the hydraulic units are in the bottom position cooperating with the lower chocks of the backup rolls, the system for adjusting the pass-line including the sloped wedge is arranged at the upper portion of the stand to cooperate with the upper chocks EAS of the upper backup roll.

In general, and in the case of a 6-High rolling mill, each of the lower and upper intermediate rolls WII and WIS comprises a roll table, extended by guide ends, with a smaller diameter. The guide ends are rotatably mounted in upper chocks EIS for the upper intermediate roll and lower chocks EII for the lower intermediate roll.

The chocks EII or EIS of each intermediate roll WII or WIS are arranged vertically between the posts of the stand to transmit the clamping force.

The rolling mill may be equipped with a first device DAX1 for adjusting the axial position of the upper intermediate roll WIS comprising a first actuator configured to move the upper chocks EIS according to the axis of the upper intermediate roll WIS and with a second device for adjusting the axial position of the lower intermediate roll comprising a second actuator configured to move the upper chocks EIS according to the axis of the lower intermediate roll WII.

The first and second devices DAX1, DAX2 are configured to move the two intermediate rolls, axially in opposite directions, in order to enable an adjustment of the axial overlap area between the two lower and upper intermediate rolls, and typically so as to allow adjusting the overlap area to the widthwise dimension of the strip.

In general, the rolling mill comprises an opening and closure system and which may comprise:

a first left opening/closure mechanism 9, with a vertical cylinder, comprising an upper portion 90 coupled, laterally to the left, to the first upper chock E1S, and a lower portion 91 coupled, laterally to the left, to the first lower chock E1I, as well as a hydraulic cylinder VR connecting the upper and lower portions 90, 91, the cylinder being configured to space the first lower and upper chocks E1I and E1S apart or to bring them together, said first opening mechanism being interposed between the left post M1 and the first upper and lower chocks,

a first right opening/closure mechanism 10, with a vertical cylinder comprising an upper portion 100 coupled, laterally to the right, to the first upper chock E1S, and a lower portion 101 coupled, laterally to the right, to the first lower chock E1I, as well as a hydraulic cylinder connecting the upper and lower portions 100, 101, the cylinder being configured to space the first lower and upper chocks apart or to bring them together, said first opening mechanism being interposed between the right post M2 and the first upper and lower chocks,

a second left opening/closure mechanism, with a vertical cylinder comprising an upper portion coupled, laterally to the left, to the second upper chock E2S, and a lower portion coupled, laterally to the left, to the second lower chock E2I as well as a hydraulic cylinder connecting the upper and lower portions, the cylinder being configured to space the first chocks apart or to bring them together, said first opening mechanism being interposed between the left post M3 and the second upper and lower chocks,

a second right opening/closure mechanism, with a vertical cylinder comprising an upper portion coupled, laterally to the left, to the second upper chock E2S, and a lower portion coupled, laterally to the left, to the second lower chock E2I as well as a hydraulic cylinder connecting the upper and lower portions, the cylinder being configured to space the first chocks apart or to bring them together, said first opening mechanism being interposed between the left post M3 and the second upper and lower chocks.

When opening the stand, the vertical cylinders of the first and second mechanisms may be deployed so as to space, on the one hand, the first upper and lower chocks E1S E1I apart, the second upper and lower chocks E1S E1I apart, thereby spacing the upper work roll WRS apart from the lower work roll WRI according to the vertical direction Z.

The vertical cylinders may also be actuated during the rolling operations, under the pressure of the hydraulic units PT to balance the upper and lower work rolls, in particular with regards to vertical forces.

The upper work roll WRS and the lower work roll WRI may typically comprise transmission shafts ARB coupled to a motor drive for directly driving the lower work roll and the upper work roll in rotation, in opposite directions. The use of transmission shafts coupled to a motor drive to directly drive the work rolls ensures and efficient and constant transmission of the motor torque. This improves the accuracy and the stability of rolling, thereby reducing the risks of slip and wear.

During rolling, the work roll is subjected to the action of the strip which includes the clamping vertical force FS.

As illustrated in FIG. 10, three main horizontal forces applied on the roll table of the work roll comprise:

the horizontal component of the clamping force FC of the roll bearing on the work roll,

half the tension difference T between that of the inlet strip Tf and that of the outlet strip Tb (1/2T)

the rolling roll force CirF due to the transmission of the motor torque to the work roll, when the work rolls are directly driven by the motor drive.

The work roll is also subjected to the horizontal component of the forces FE exerted by the chocks E1S, E1I, E2S, E2I on the guide ends of the work roll.

When the axes of the rolls are contained in the same vertical plane, the rolling roll force due to the transmission of the motor torque on the work roll, then the roll is held by its guide ends by the chocks, cambers the work roll thereby creating a deflection with a maximum amplitude between the guide ends, directed on the upstream side with respect to the roll according to the running direction of the strip.

Shifting the axis of the work roll with respect to the axis of the roll bearing on the work roll according to the direction of the strip, allows obtaining a horizontal component of the rolling clamping force FC opposite to the horizontal component of the roll force, thereby allowing balancing the work roll, and thus reducing the horizontal component of the deflection due to the motor torque.

As illustrated in FIG. 9, it is desirable to be able to adjust the value of the shift OFS between the axis of the (lower or upper) work roll and the axis of the roll bearing on the work roll (namely the intermediate roll or the backup roll) progressively (rather than all or nothing), in particular during the rolling operations, and so as to be able to optimally control the horizontal balancing of the work roll, during the rolling operations.

The present disclosure finds a particular application, for small-diameter work rolls, typically those wherein the ratio of the diameter of the work roll to the maximum width of the strip is less than 0.23 and which are more sensitive to cambering than rolls with a larger diameter.

To this end, the rolling mill comprises a system 3 for adjusting a side shift configured for implementing a side shift OFS, viewed according to the rolling direction DL between, on the one hand, an axis Awr of the lower work roll WRI or respectively of the upper work roll WRS and, on the other hand, an axis Ap of a roll bearing on the work roll.

The roll bearing on the lower or upper work roll WRI, WRS consists of the lower WII, or upper WIS, intermediate roll when the rolling mill is a 6-High rolling mill.

The roll bearing on the lower or upper work roll WRI, WRS consists of the lower WAI, or upper WAS, backup roll when the rolling mill is a 4-High rolling mill.

Such a system 3 for adjusting a side shift comprises:

a first left pushing mechanism 31g between a left one M1 of the posts of the first pair and the first upper chock E1S and first lower chock E1I set, the first left mechanism being configured to exert a pushing force on the first upper chock E1S and first lower chock E1I set to move said set in a first way according to the rolling direction DL

a first right pushing mechanism 31d between the other right one M2 of the posts of the first pair, on the one hand, and the first upper chock E1S and the first lower chock E1I, the first right mechanism being configured to exert a pushing force on the first upper chock E1S and first lower chock E1I set to move said set in a second way according to the rolling direction DL

a second left pushing mechanism 32g between a left one M3 of the posts of the second pair, on the one hand, and the second upper chock E2S and second lower chock E2I set, the second left mechanism being configured to exert a pushing force on the second upper chock E2S and second lower chock E2I set to move said set in the first way according to the rolling direction DL

a second right pushing mechanism 32d between the other right one M4 of the posts of the second pair, on the one hand, and the second upper chock E2S and second lower chock E2I set, the second right mechanism being configured to exert a pushing force on the second upper chock E2S and second lower chock E2I set to move said set in the second way according to the rolling direction DL.

The adjustment system may also comprise a monitoring and control unit or controller, synchronising:

the first left pushing mechanism 31g and the second left pushing mechanism 32g to simultaneously push the first upper and lower chocks, on the one hand, and, on the hand, the second upper and lower chocks, to move the axes of the lower and upper work rolls, in the first way according to the rolling direction,

the second right pushing mechanism 31d and the second right pushing mechanism 32d to simultaneously push the first upper and lower chocks, on the one hand, and, on the hand, the second upper and lower chocks, to move the axes of the lower and upper work rolls, in the second way according to the rolling direction,

In general, the first and second left pushing mechanisms 31g, 32g and the first and second right pushing mechanisms 31d, 31d are antagonist, the control unit of the right mechanisms 31g, 32g, and the left mechanisms 31d, 32d, in a reverse manner, namely:

when the left mechanisms 31g, 32g exert a pushing force on the chocks, the right mechanisms 31d, 32d retract so as not to oppose the movement of the chocks of the work rolls in the first way

when the right mechanisms 31d, 32d exert a pushing force on the chocks, the left mechanisms 31g, 32g retract so as not to oppose the movement of the chocks of the work rolls in the second way.

The monitoring and control unit synchronises the first and second left pushing mechanisms 31g, 32g and the first and second right mechanisms 31d, 32d, to ensure backlash compensation, to the right and to the left of the upper and lower chocks E1I, E1S, E2I, E2S.

In general:

the first left pushing mechanism 31g may be interposed between the left post M1 and said first left opening/closure mechanism 9

the first right pushing mechanism 31d may be interposed between the right post M2 and said first right opening/closure mechanism 10,

the second left pushing mechanism 32g may be interposed between the left post M3 and said second right opening/closure mechanism,

the second left pushing mechanism 32d may be interposed between the left post M4 and said second right opening/closure mechanism.

According to the present disclosure, and as illustrated in particular in the figures of the present application, the first left and right pushing mechanisms 31g, 31d, and the second left and right pushing mechanisms 32g, 32d comprise all or part of the rotary helical pushing devices 4.

In particular, the adjustment system comprises:

a (first left) rotary helical pushing device for the first left pushing mechanism 31g,

a (first right) rotary helical pushing device for the first right pushing mechanism 31d,

a (second left) rotary helical pushing device for the second left pushing mechanism 32g,

a (second right) rotary helical pushing device for the second right pushing mechanism 32d.

Each rotary helical pushing device comprises a first part 5 bearing (directly or indirectly) on one of the posts M1, M2 for the first pair or respectively bearing on one of the posts M3, M4 for the second pair and a second part 6 configured to laterally push the first lower and upper chocks E1I, E1S when it comes to the first (left or right) pushing mechanisms, or respectively to respectively push the second lower and upper chocks E2I, E2S when it comes to the second (left and right) pushing mechanisms.

The first part 5 and the second part 6 of each rotary helical pushing device are pivotably articulated relative to one another, about an axis of rotation A4 under the action of an actuator AT, said axis of rotation A4 typically oriented according to the rolling direction DL (namely according to the X direction).

The first part 5 and the second part 6 comprise helical guide surfaces 7 around said axis of rotation A4, bearing on each other, configured to cause a spacing of the second part 6 relative to the first part 5 in the direction of the axis of rotation A4, upon a relative rotation between the first part 5 and the second part 6.

The helical guide surfaces 7 may consist of cam surfaces of the first part 5 and of the second part 6 which respectively consist of a first cam and a second cam, and as illustrated according to the embodiment in the figures.

According to a non-illustrated embodiment, the helical guide surfaces may also consist of respectively inner and outer threads meshing together between the first part 5 and the second part 6, the first part 5 and the second part 6 cooperating together by screwing. The inner thread and the outer thread may be simple threads distributed between the first part and the second part

The helical guide surfaces may also consist of multiple threads, including several inner threads, simultaneously meshing with several outer threads, the inner and outer threads being respectively arranged respectively between the first part 5 and the second part 6.

Thus, by controlling the angular position of the second part 6 with respect to the second part 5, it becomes possible to adjust the spacing between the second part 6 and the first part 5, according to the direction of the axis of rotation 4 and thus exert a pushing action by increasing the spacing between the two cams 5 and 6 or, on the contrary, reducing the spacing on the other side of the chocks in order to compensate for the backlash on the opposite side of the chocks undergoing the push.

According to the present disclosure, this consists of a preferably progressive control, namely the angular position of the second part 6 with respect to the first cam can take on different intermediate angular positions between:

a first angular position between the second part 6 and the first part 5 corresponding to a minimum spacing between the second cam 6 and the first cam 5

a second angular position between the second part 6 and the first part 5 corresponding to a maximum spacing between the second cam 6 and the first cam 5.

Thus, the intermediate positions could allow obtaining different spacings between the two parts 5, 6, the spacings increasing from the first angular position up to the second angular position. In particular, the parts 5, 6 could enable a continuous adjustment between the extreme angular positions between the first position and the second position.

In particular, and as illustrated in the embodiment of the rotary helical pushing device, the helical guide surfaces 7 may extend according to one or more helical path(s) around said axis of rotation A4 on the first part 5 and on the second part 6.

In particular, and according to an embodiment shown in FIGS. 7A to 7C:

the first part 5 forms a first cam which may comprise a first helical guide surface 70 extending over a first angular portion 71 of the first cam around said axis of rotation A4 and a second helical guide surface 71 extending over a second angular portion of the first cam,

the second part 6 forms a second cam which comprises a third helical guide surface 72 extending over a first angular portion of the second cam and a fourth helical guide surface 73 extending over a second angular portion of the second cam.

In general, the first angular portion and the second angular portion (of the first part in particular the cam and of the second part in particular the cam) may have the same angular range lower than or equal to 180°.

The first helical guide surface 70 and the second helical guide surface 71 of the first cam are configured to cooperate in guidance simultaneously with the third helical guide surface 72 and the fourth helical guide surface 73 of the second cam.

The first angular portion and the second angular portion of the first cam, are respectively smaller than or equal to 180°. For example, and according to one embodiment, the first helical guide surface 70, running along a helical path, extends over an angular portion of 180° around said axis of rotation and the second helical guide surface 71, running along a helical path, extends over a second angular portion of 180°.

The first angular portion and the second angular portion of the second cam 6 are respectively smaller than or equal to 180°. For example, and according to one embodiment, the third helical guide surface 72, extends over an angular portion of 180° around said axis of rotation and the fourth helical guide surface 73, running along a helical path over a second angular portion of 180°.

A first benefit of rotary helical pushing devices is their small bulk in comparison with the prior art with slopped wedges described in the introduction.

In particular, the helical guide surfaces 70 of the parts 5, 6 of each rotary helical pushing device 4 may be arranged overlapping, according to the transverse direction Y, the width of one of the posts M1, M2 M3, M4 on which the rotary helical pushing device 4 bears; the helical guide surfaces 7 with a diameter D of each rotary helical pushing device may advantageously be contained according to the transverse direction Y, according to the widthwise direction of the post.

Thus, and for example in FIG. 6, the rotary helical pushing device of the left pushing mechanism 31g has a bulk of the helical guide surfaces 7, with a diameter D, which is contained according to the widthwise direction of the left post M1 of the first pair, and the rotary helical pushing device of the right pushing mechanism 31d has a bulk of the helical guide surfaces 7, with a diameter D, which is contained according to the widthwise direction of the right post M2 of the first pair.

Similarly, the rotary helical device of the left pushing mechanism 32g has a bulk of the helical guide surfaces 7, with a diameter D, which is contained according to the widthwise direction of the left post M3 of the second pair, and the rotary helical pushing device of the right pushing mechanism 32d has a bulk of the helical guide surfaces 7, with a diameter D, which is contained according to the widthwise direction of the right post M4 of the second pair.

In general:

each of the first left pushing mechanism 31g and of the first right pushing mechanism 31d comprises one single pair of first part 5 and second part 6 (in particular one single pair of first cam and second cam) extending in height, overlapping the height of the first upper chock E1S and first lower chock E1I set; in particular and as shown to the left in FIG. 5, the helical guide surfaces 7 with the diameter D of the first (left or right) mechanism may extend, overlapping, in the Z direction, the first upper and lower chocks E1I, E1S.

each of the second left pushing mechanism 32g and of the second right pushing mechanism 31d comprises one single pair of first part 5 and second part 6 (in particular one single pair of first cam and second cam) extending in height, overlapping the height of the second upper chock E2S and second lower chock E2I set, in particular, the helical guide surfaces 7 with the diameter D of the first (left or right) mechanism may extend, overlapping, in the Z direction, the second upper and lower chocks E2I, E2S.

By using one single pair of parts 5, 6 for each pushing mechanism, the system simplifies the design while ensuring an accurate adjustment of the side shift. This improves the efficiency of adjustment and reduces the mechanical complexity. This configuration allows covering the entire height of the chocks, thereby ensuring a uniform distribution of the applied forces. This minimises stresses on the chocks and improves the stability of the work rolls. By reducing the number of required components, the system reduces the maintenance needs and the risks of failure, thereby contributing to a more reliable and durable operation of the rolling mill.

Thus, the adjustment system may comprise only four rotary helical pushing devices 4 respectively for the first left 31g and right 31d, 31d pushing mechanisms, and the second left 32g and right 32d pushing mechanisms.

According to a beneficial embodiment (illustrated in the figures) limiting the bulk of the rolling mill in the transverse direction Y, the actuators AT of the helical pushing devices may consist of cylinders, typically hydraulic or electric cylinders, extending longitudinally according to the height of the posts M1, M2, M3, M4. By integrating the cylinders along the posts, the system optimises space and reduces bulk, thereby facilitating access for maintenance and improving the ergonomics of installation.

A first left cylinder extending substantially longitudinally according to the height of the (first) left post M1 configured for control of the angular position of the second part 6 with respect to the first part 5 of the first left pushing mechanism 31g.

A second right cylinder extending substantially longitudinally according to the height of the (second) right post M2 configured for control of the angular position of the second part with respect to the first part of the first right pushing mechanism 31d.

A third left cylinder extending substantially longitudinally according to the height of the (third) left post M3 configured for control of the angular position of the second part with respect to the first part of the second left pushing mechanism 32g.

A fourth right cylinder extending substantially longitudinally according to the height of the (fourth) right post M4 configured for control of the angular position of the second part with respect to the first part of the second right pushing mechanism 31d.

The second part 6 may have an extension 60 or a lever arm extending outwardly, radially to said second part 6 around the axis of rotation 4, beyond the diameter D of the helical guide surfaces 7, for example beyond the third and fourth guide surfaces 72, 73.

Said extension 60, or more generally the lever arm, projects from the post (in particular the first post M1, second post M2, third post M3, or fourth post), typically outwardly from the stand in the transverse direction Y, the cylinder VR (in particular the first cylinder, second cylinder, third cylinder or fourth cylinder) being articulated by its first end of the hydraulic cylinder on said extension 60 or more generally on the lever arm.

All or part of the cylinders VR (namely the first cylinder, the second cylinder, the third cylinder and the fourth cylinder) are articulated to said second part 6 via a first end of the cylinder, and articulated via a second end to one of the posts M1, M2, M3, M4 via a pivot axis Av, in particular parallel to the axis of rotation 4 of said pushing device with rotary cams 4.

When the cylinder is deployed or retracted, it causes rotation of the second part 6 relative to the first part 5, while slightly pivoting relative to the post with respect to said pivot axis Av.

In order to limit bulk according to the transverse direction Y, by approaching the substantially vertical cylinder VR and the post as much as possible, an in-depth cutout ECH of the post may extend right opposite the cylinder coupled to the post, according to the Y direction. When the cylinder is deployed or retracted, this enables the cylinder to pivot about said pivot axis Av, while penetrating the cutout ECH, and without interfering with the post.

According to another embodiment, (not illustrated), the rotational movement between the first part 5 and the second part 6 may be obtained by a ring gear mounted secured in rotation to the second part (or to the first part), coaxial with said axis of rotation, the ring gear meshing via a motor pinion driven by an electric geared motor forming the actuator. The force or the position of the geared motor may be regulated during the control.

According to a beneficial embodiment, the first part 5 and the second part 6 are preferably enclosed within a cowling 8 protecting the helical guide surfaces 7 from the external environment, in particular the cowling comprising a cylindrical wall with an axis coaxial with the axis of rotation A4 of the rotary helical pushing device 4. Enclosing the parts (in particular of the cams) within a cowling protects the helical guide surfaces (in particular the guide surfaces of the cams or the inner and outer threads) from external contaminants, such as oils and metal particles. This reduces the need for frequent maintenance and extends the service life of the components.

The present disclosure also relates to a method for rolling a metal strip implemented by a rolling mill 1 according to the present disclosure comprising:

A. rolling the metal strip B by running between the two upper and lower work rolls held pressed on the strip through a hydraulic clamping action between the lower and upper two backup rolls WAS, WAI, and by transmission of motor torques to the upper work roll WRS and to the lower work roll WRI,

B. balancing the upper and lower work rolls, through

an upper side shift between the axis of the upper work roll WRS and the axis of the roll bearing on the work roll,

a lower side shift between the axis of the lower work roll WRI and the axis of the roll bearing on the roll, and wherein the upper and lower side shift OFS are obtained through a progressive control in real-time of the angular position of the first part 5 with respect to the second part 6 of each rotary helical pushing device 4 to ensure a lateral push of the lower and upper first chocks E1I, E1S and of the lower and upper second chocks E2I, E2S of the lower and upper work rolls.

The rolling method using a progressive control in real-time of the angular portion of the parts 5, 6 enables an accurate adjustment of the side shift during rolling. This ensures an optimum balancing of the work rolls, thereby improving the quality of the end product.

The real-time control allows rapidly adapting the rolling parameters to changing conditions, thereby optimising the efficiency and the productivity of the process.

To sum up, the present disclosure may have all or part of the following benefits.

1) The use of rotary helical pushing devices in the system for adjusting the side shift enables an accurate and progressive adjustment of the position of the chocks of the work rolls. This improves balancing of the horizontal forces and reduces cambering of the rolls, which is essential to preserve the quality of rolling, in particular when the diameters of the work rolls are small.

2) The use of rotary helical pushing devices allows limiting the overall bulk of the rolling mill in the transverse direction Y, and in comparison with the rolling mill provided with rectilinear cam pushing devices, as disclosed in US 4,736,609.

3) The use of rotary helical pushing allows protecting the guide surfaces by a cowling, thereby avoiding these surfaces being soiled by oils and rolling metal particles contained in the oil.

Expressions such as “comprise”, “include”, “incorporate”, “contain”, “is” and “have” are to be construed in a non-exclusive manner when interpreting the description and its associated claims, namely construed to allow for other items or components which are not explicitly defined also to be present. Reference to the singular is also to be construed in be a reference to the plural and vice versa.

The articles "a" and "an" may be employed in connection with various elements and components, processes or structures described herein. This is merely for convenience and to give a general sense of the processes or structures. Such a description includes "one or at least one" of the elements or components. Moreover, as used herein, the singular articles also include a description of a plurality of elements or components, unless it is apparent from a specific context that the plural is excluded.

As used herein in the specification and in the claims, the phrase “at least one”, in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified.

A person skilled in the art will readily appreciate that various features, elements, parameters disclosed in the description may be modified and that various embodiments disclosed may be combined without departing from the scope of the invention. For example, various aspects of the present disclosure may be used alone, in combination, or in a variety of arrangements not specifically described in the embodiments described in the foregoing and is therefore not limited in its application to the details and arrangement of components set forth in the foregoing description or illustrated in the drawings. For example, aspects described in one embodiment may be combined in any manner with aspects described in other embodiments.

Having described above several aspects of at least one embodiment, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be aspects of this disclosure. Accordingly, the foregoing description and drawings are by way of example only.

LIST OF THE REFERENCE SIGNS

1: Rolling mill,

2. Stand,

3. Side-shift adjustment system,

31g, 31d. First side-shift adjustment mechanisms, respectively left and right,

32g, 32d. Second side-shift adjustment mechanisms, respectively left and right,

4. Helical pushing device,

A4. Axis of rotation,

5, 6, respectively first part and second part,

7. Helical guide surfaces,

71, 72, 73, 74. First, second, third and fourth helical guide surface

B. Strip (metallic),

M1, M2. Posts (first pair of posts of the stand, respectively left and right),

M3, M4. Posts (second pair of posts of the stand, respectively left and right),

PT: Hydraulic clamping units,

PST. Pass-line adjustment system

WRI. Lower work roll,

WRS. Upper work roll,

WAI Upper backup roll,

WAS. Lower backup roll,

WII. Lower intermediate roll,

WIS. Upper intermediate roll,

E1S, E2S. First upper chock and second upper chock (for the upper work roll WRS),

E1I, E2I. First lower chock and second lower chock (for the lower work roll WRI),

EII, EIS. Lower chock and upper chock (for the intermediate roll),

EAI, EAS. Lower chock and upper chock (for the backup roll),

8. Cowling,

9. First opening/closure mechanism, left,

90, 91. Respectively lower and upper portions,

10 First opening/closure mechanism, left,

100, 101. Respectively lower and upper portions