EP1601474A2 - Method for changing the configuration of a rolling mill and advanced rolling mill for carrying out said method - Google Patents

Abstract

The invention relates to a method for changing the configuration of a rolling mill comprising at least two working cylinders and two support cylinders, means for applying a tightening effort and two sets of hydraulic camber actuators, and at least two working cylinders. According to the invention, at least two types of working cylinders (Cl, C2) are created. Said cylinders respectively have a larger and a smaller diameter. The rolling mill switches from a quarto configuration to a sexto configuration and vice-versa. The larger-diameter cylinders (Cl, C'l) are used as working cylinders in the quarto configuration and are used in the sexto configuration as intermediary cylinders between each support cylinder and a smaller-diameter cylinder (C2, C'2) used as a working cylinder.

Description

 PROCESS FOR CHANGING THE CONFIGURATION OF A ROLLER AND IMPROVED ROLLER FOR IMPLEMENTING THE

PROCESS

The subject of the invention is a process for changing the configuration of a rolling mill and an improved rolling mill for implementing the process.

It is known that a rolling mill generally comprises a holding cage having two spaced apart columns between which are arranged a set of superimposed rolls with substantially parallel axes and comprising, at least, two working rolls, respectively upper and lower which define an air gap for the product to be laminated and bear, on the side opposite the product, respectively on two support rollers. Each cylinder is rotatably mounted, at its ends, on bearings carried by support pieces called chocks, which are slidably mounted in windows provided in the two columns of the cage, parallel to a substantially vertical clamping plane in which are placed substantially the axes of the cylinders. To this end, each chock is provided, on either side of the clamping plane, sliding faces cooperating with corresponding guide faces formed on the two sides of the corresponding window of the cage.

Because the working rolls have a smaller diameter than the support rollers, their chocks are narrower and their guide faces must therefore be more tightened. In the old rolling stands, these guide faces are often formed on legs fixed to the chocks of the support rolls and extending towards the rolling plane

More recently, it has been proposed to provide the guide faces of the working chocks on the ends of guide pieces integral with the cage and extending projecting in each window, on either side of the clamping plane.

Hydraulic jacks, called balancing cylinders, make it possible to adjust the relative positions of the cylinders for product engagement or for disassembly of the cylinders. During rolling, the working rolls tend to move away from each other and the air gap between the facing generators must be maintained by applying a clamping force between the chocks of the support rolls. The rolling force to be exerted on the product to obtain a certain rate of reduction in thickness depends, in particular, on the diameter of the working rolls which determines the length of the reduction zone in which the metal flows as well as on the characteristics. mechanical and metallurgical properties thereof such as its elastic limit and its composition, for example common low-carbon low-alloy steel, stainless steel, alloy steel, etc.

The rolling stands used in the metallurgical industry can have several types of configuration depending on the nature of the product to be treated.

The most common rolling mills, in particular for large productions, are of the “quarto” type comprising two working rolls each associated with a support cylinder of larger diameter, or else of the “sexto” type in which intermediate rolls are interposed between each working cylinder and the corresponding support cylinder. This arrangement makes it possible, in particular, to offset axially, with respect to one another, the two intermediate rolls in order to apply the rolling force, not over the entire table of rolls, but only over the width of the product. This reduces the deformation of the cylinders and a product with better flatness is obtained.

Furthermore, the use of intermediate rolls makes it possible to use working rolls of smaller diameter and, thus, to reduce the rolling force necessary for the same thickness reduction.

On the other hand, the fact that the clamping forces are applied, normally, between the two ends of the two support rolls and that the laminated product, of variable width, generally does not completely cover the length of the working rolls, each roll can bend under the action of applied forces. This results in a variation in thickness of the space for passage of the strip between the working rolls, which gives rise to profile and flatness defects. In addition, the forces applied during rolling being extremely large, there is necessarily a slight flattening of the external face of each cylinder, due to the so-called Hertz pressure.

There are therefore, during rolling, flatness defects which can be measured downstream of the rolling mill, in order to correct them.

To this end, in recent years, sophisticated systems have been developed which make it possible to modulate the distribution of the stresses applied to the product during rolling.

In a commonly used system, controlled bending forces are applied to the two ends of the shaft of each working cylinder in order to achieve cambering effects making it possible to correct the distribution of stresses. For this purpose, the balancing jacks can be used to adjust the spacing of the working rolls.

These jacks can be interposed between the chocks of the working cylinders. Such an arrangement, however, makes it more difficult to supply the cylinders with hydraulic fluid and it is generally preferred to mount the cylinders in the chock guide parts which, in recent installations, are often protruding from parts massive fixed, on each side of the window, on the two uprights of each column of the cage. It is easier, in fact, to mount the hydraulic circuits on these parts which are called, for this reason "hydraulic blocks".

In this case, the jacks cooperate with support members often called "ears" formed on each lateral side of the chock, on either side of the clamping plane. Usually, a so-called positive bending is carried out, by spacing the chocks of the two working rolls to compensate for an excess thickness of the central part of the product, but it is often advantageous to also have the possibility of carrying out a so-called negative bending, by tightening chocks. of the two working rolls, to compensate for an excess thickness of the edges of the product.

To achieve bending in both directions, one can use single-acting cylinders each acting in a cambering direction but such an arrangement complicates the production of hydraulic blocks since, on each side of the clamping plane, the chock must be associated with two cylinders each acting in one direction. Now, at the level of the working cylinders and at near the strip, the available space is quite limited and makes it difficult to install such a number of jacks.

To reduce the number of cylinders, double acting cylinders are therefore often used, the rod of which is fixed to the chock, in order to act in both directions.

In the so-called “sexto” rolling mills, the bending forces can also be applied to the intermediate rolls which are interposed between each working roll and the associated support roll and can also be moved axially, in opposite directions, in order to to apply the rolling force, only over the width of the product, which makes it possible to obtain a product with better flatness.

Because flatness defects are easier to correct on a sexto rolling mill with small rolls, this type of rolling mill is often used for rolling relatively small thicknesses. However, it sometimes happens that the thickness of the rolling mill product must vary over a wide range, in particular for the rolling of non-ferrous metals.

However, the use of small diameter cylinders makes it more difficult to engage the product between the cylinders and can lead to a refusal of engagement.

To solve this problem, it has been proposed in document JP-A-63 013 603 to use working cylinders of fairly large diameter, in quarto mounting, for large thicknesses and to replace each working cylinder with a assembly comprising an intermediate cylinder and a working cylinder of smaller diameter, to thus pass into a sexto configuration better suited to small thicknesses.

To use the same camber cylinders, the chocks of the working cylinders in quarto and of the intermediate cylinders in sexto are adapted so that their bearing ears are substantially at the same level in each of the configurations.

On the other hand, the camber cylinders of the working cylinders in sexto are not used in the quarto assembly.

Such an arrangement therefore makes it easy to adapt to a significant variation in the thickness of the product to be laminated, for example for rolling a copper or aluminum slab in a reversible cage.

However, it appeared, even in the case where the rolling mill is not intended for a significant variation in the thickness of the product, it would be advantageous to have the possibility of rapidly modifying the configuration of the cage in order to adapt , not to a variation in thickness, but to a modification of the characteristics of the product to be laminated, for example its hardness.

It has been discovered, in fact, that such a configuration change would make it easy to adapt to the needs of users who are constantly evolving in the direction of a diversification of the qualities demanded.

Thus, in the automotive industry, we are moving towards the use of steels having very precise grades allowing high performance to be obtained. In addition, it is sought to reduce, as much as possible, the weight of the products produced without reducing their resistance and therefore, for the same performance, sheets having increasingly thinner thicknesses are required which require reduction rates. while maintaining the same requirements for regularity of thickness, flatness and surface quality.

For example, for the body sheet, we have seen successively appear the grades called, in trade, CQ, DQ, DDQ, EDDQ whose elastic limit extends from 180Mpa to 250 Mpa as well as very hard steels having a high elastic limit (HSLA) of up to 600 Mpa. Conversely, very soft (IF) steels with very low carbon are also required, the elastic limit of which is of the order of 160 MPa.

On the other hand, even the rolling process must be able to adapt to the quality of the steels treated, for example to take account of the fact that, in a tandem rolling mill, rolling determines, by work hardening, a progressive increase in the hardness of the product and, therefore, the rolling force to be applied for the same thickness reduction, from one cage to the next.

As a result, the means for applying the clamping force risk being saturated with force if the hardness of the starting product is too high. In the case, for example, of a tandem rolling mill, it is possible to adapt the configuration of the successive cages to an increase in the hardness of the product by first using one or more quarto cages followed by sexto cages or so-called cages Z.High which allow, as we know, to further reduce the diameter of the working rolls.

However, the cage itself must be adapted to the configuration, since the height of the window in which the overlapping chocks must be threaded depends on the number of cylinders and their diameters.

In addition, the height of the hydraulic blocks also depends on the configuration since it is necessary to provide, in a sexto cage, support and guide parts for the intermediate cylinders.

Furthermore, as indicated above, it is necessary to have different means for improving the flatness and the surface quality of the rolled product. For example, in addition to the bending devices described above, it is advantageous to have the possibility of modulating the rolling force along the generator of contact with the working cylinder or the intermediate cylinder, by transmitting the rolling force. by means of a cylinder comprising an envelope rotatably mounted around a fixed shaft and bearing on it by means of a series of jacks making it possible to vary the distribution of the stresses along the bearing generator .

All these devices, as well as other improvements, developed over several years, have made it possible, in the cold rolling technique, in particular in tandem rolling mills, to continuously improve the quality of the final product. However, these devices are expensive and are therefore only profitable from a certain production volume, especially since this profitability must be maintained for several years to justify the amount of investment.

To solve such a problem, the invention will make it possible to extend the production range of a rolling installation, by giving the possibility of adapting the configuration of the rolling mill to the structural and dimensional characteristics of the product to be treated in order to go through example, from a quarto configuration to a sexto configuration or, even, to a so-called "Z.High" configuration. However, this change of configuration must be carried out very quickly because there is a tendency, in modern installations, to work in a continuous line by welding end to end metal strips of different qualities and therefore the time for configuration change must be compatible with other online operations.

However, in the arrangement of document JP-A-63 013 603, it is necessary to use double-acting cylinders to achieve bending in both directions, respectively positive and negative. Therefore, the rods of the cylinders must be removably fixed on the chocks and these disassembly and reassembly operations of the cylinders extend the time necessary for the configuration change. Such a drawback can be accepted when one simply has to adapt to a change in thickness of the product. On the other hand, if the configuration of the rolling mill is modified, according to the invention, so as to adapt to a change in the product to be rolled, it is necessary to reduce the replacement time of the rolls as much as possible.

So as not to have to dismantle the cambering cylinders, it is therefore preferable to use only single-acting cylinders which bear in one direction on the chocks without being connected to them. However, as indicated above, this doubles the number of jacks and it is then difficult to find the necessary space at the level of the working rolls and near the strip, the travel of which must normally be continued. However, it is necessary as much as possible, that the camber cylinders remain fixed on the cage.

In addition, the cylinders and in particular the working cylinders wear out in service and must be periodically removed for cleaning and rectification of their surface. Their diameter therefore varies over a certain range. To allow immediate replacement, there is therefore, for each category, a set of cylinders having substantially the same diameter, to the nearest wear range.

These cylinders are, however, very expensive and the number should be limited as much as possible. In addition, each cylinder is carried by two chocks which are also complex and expensive components. Their disassembly is quite long and it is therefore preferable, for a replacement, to remove the cylinder as a whole with its chocks to replace it with a new cylinder provided in advance with its chocks. This requires, however, to have a large number of chocks.

The object of the invention is to solve all of these problems by means of a method and an installation making it possible to easily and quickly change the configuration of a rolling mill in order to better adapt to the nature of the product to be laminated. The invention also makes it possible to use the same cylinders with their chocks in several configurations and, thus, to limit the number of cylinders and chocks with which the installation must be equipped.

In accordance with the invention, the rolling mill is equipped with at least two types of working rolls having at least two different diameters, respectively a larger one and a smaller diameter and, while keeping the same stand, the same means of application clamping and bending forces and the same type of support cylinders, the rolling mill is changed from a quarto configuration to a sexto configuration and vice versa, only changing the arrangement of the cylinders interposed between the support cylinders, the cylinders of larger diameter being used, in the quarto configuration as working cylinders and, in the sexto configuration as intermediate cylinders interposed respectively between each support cylinder remaining in place and a cylinder of smaller diameter used as working cylinder.

In a particularly advantageous manner, the rolling mill is equipped with three types of working rolls having respectively a large, a medium and a small diameter and the rolling mill is given one or the other of at least three configurations, respectively at minus a quarto configuration in which the large or medium diameter cylinders are used as working cylinders, a sexto configuration in which the medium diameter cylinders are used as working cylinders and the large diameter cylinders as intermediate cylinders and a sexting configuration type Z.High in which small diameter cylinders are used as working cylinders and medium cylinders diameter as intermediate cylinders between each small diameter working cylinder and a support cylinder.

According to another preferred characteristic of the process, single-acting cylinders are used as positive or negative camber cylinders which bear in one direction on the chocks.

On the other hand, each cylinder remains equipped with its chocks, these can be simply turned over according to the position of the cylinder in the cage.

Thanks to the invention, all the means for applying and adjusting the distribution of the clamping forces remain in place in the cage during a configuration change. However, since the cylinders of the same type have, after rectification, diameters varying over a certain range, it may be advantageous, for a quarto configuration, to place larger support cylinders in the cage. diameter only for a sexto configuration.

In addition, it should be noted that, for maintenance and spare parts, the invention makes it possible to superimpose the wear ranges of the working and intermediate rolls and, thus, to have a greater total wear range of the rolls even if surface reprocessing is to be redone. Similarly, for the support cylinders, the invention makes it possible to associate the wear ranges in order to increase the total range.

The invention also covers an improved rolling mill for implementing the method, comprising, in general, a holding cage, a set of superimposed cylinders mounted to rotate, each on two chocks, means for applying a clamping force and means for applying vertical bending forces, at least on the chocks of the working rolls, respectively in a positive direction of spacing of said chocks relative to the rolling plane and in a negative direction of approximation and comprising, on each side of the clamping plane, two sets of hydraulic camber cylinders, respectively upper and lower, which cooperate with support members formed on the sides of each chock, on either side of the clamping plane .

According to the invention, the rolling mill is equipped with at least two pairs of working rolls having at least two different diameters and usable as working cylinder inside the same cage in at least two rolling mill configurations, respectively a quarto configuration in which the two larger diameter cylinders are used as working cylinder and a sexto configuration in which the two cylinders of smaller diameter are used as working cylinder and the cylinders of larger diameter as intermediate cylinders disposed, respectively, between each working cylinder of smaller diameter and the corresponding support cylinder, keeping, in both configurations, the same cage, the same type of support cylinders and the same means of applying clamping forces and cambering forces.

In a preferred embodiment, the rolling mill is equipped with at least three pairs of rolls having respectively a large, a medium and a small diameter and usable as working rolls inside the same cage in at least three configurations of the rolling mill, respectively at least one quarto configuration in which the large or medium diameter cylinders are used as working cylinders, a sexto configuration in which the medium diameter cylinders are used as working cylinders and the large diameter cylinders as cylinders intermediate and a Z.High type sext configuration in which the small diameter cylinders are used as working cylinders associated with lateral support means and the medium diameter cylinders as intermediate cylinders.

According to another particularly advantageous characteristic of the invention, for the change of configuration, the cylinders remain equipped with their chocks and the chocks support members, at least cylinders of larger diameter, are offset in height relative to the axis of rotation of the cylinder, so that, after displacement in height of the cylinder of larger diameter and 180 ° inversion of its chocks around the axis, the support members of said cylinder are substantially at the same level relative to in the rolling plane, respectively in the quarto configuration and in the sexto configuration, and that the same camber cylinders act in the positive direction on the same chocks, respectively in the working position in the quarto configuration and, after turning, in the intermediate position in the sexto configuration.

In a preferred embodiment, the support members of the chocks of the two working rollers which, in a conventional manner, project in relation to the corresponding sliding faces, are placed, in each configuration, substantially at the plane and each support member of a first working chock placed on a first side of the rolling plane is provided with a recess for the passage of the rod of a cambering cylinder placed on said first side and passing through the plane rolling to take support, in the positive direction, on a corresponding support member of the second working chock placed on the second side of the rolling plane and provided with a recess for passage of the rod of a bending cylinder placed on said second side and crossing the rolling plane to bear, in the positive direction, on the support member of the first working chock.

According to another preferred characteristic of the invention, the sets of camber cylinders, respectively upper and lower, are centered substantially in two planes parallel to the clamping plane and symmetrically spaced apart on either side thereof. As indicated above, each column of the cage is provided with two hydraulic blocks fixed, on either side of the clamping plane, on the sides of the corresponding window and comprising guide parts in which are housed bending cylinders, respectively upper and lower, and which extend in projection, towards the inside of the cage, up to a guide face parallel to the clamping plane and cooperating, in the quarto and sexto configurations, with a corresponding sliding face of a working chock.

According to another characteristic of the invention, in the sexto configuration, the sliding faces of the chocks of larger diameter serving as intermediate chocks, cooperate with guide faces formed on support pieces removably mounted inside. of the corresponding window of the cage, respectively, above and below the two protruding parts of the hydraulic block, these support parts possibly being legs fixed, in a removable manner, on the chocks of the two support cylinders. According to another preferred characteristic of the invention, each projecting part of a hydraulic block carries two groups of jacks acting respectively towards the rolling plane and on the side opposite to it, by bearing on said projecting part, and the chocks support members are placed substantially on three levels which remain the same in all configurations, respectively a central support level of the working chocks, corresponding substantially to the rolling plane, and two levels, respectively upper and lower, support cylinders, placed respectively above and below the projecting parts of the hydraulic blocks.

Preferably, each protruding part of a hydraulic block carries, in a central zone, at least one pair of opposite jacks acting respectively in the direction of approach and away from the rolling plane and, on either side of this central zone, two lateral jacks acting in the direction of separation from the rolling plane.

According to another particularly advantageous characteristic of the invention, each chock of a cylinder of large or medium diameter, consists of three adjoining parts, respectively a central support part of a bearing for centering the corresponding cylinder and two end parts of support, each of two support members extending on either side of the clamping plane, fixed on two lateral sides, perpendicular to the axis, of the central part, in a removable manner allowing, on the one hand, to secure the central part with the two end parts for the transmission of the clamping forces and, on the other hand, to rotate the end parts relative to the central part, after separation of the three parts.

Furthermore, the central part of each chock is provided, on each side of the clamping plane, with a support member for at least one central cambering cylinder placed on a first side of the rolling plane, said support member comprising at least one recess for the passage of the rod of at least one central cambering cylinder placed on the other side of the rolling plane.

In this case, each hydraulic bending block placed on one side of the clamping plane advantageously comprises a central group of jacks comprising at least two pairs of opposite jacks acting respectively on the support members of the central parts of the two working chocks placed on either side of the rolling plane, each pair comprising two jacks acting respectively in the positive direction and in the negative direction on a support member of one of the chocks, and each positive camber cylinder of a first chock placed on a first side of the rolling plane is supported on the other side on the hydraulic block and crosses said rolling plane passing through a recess in the corresponding support member of a second chock placed on the other side of said rolling plane. In a preferred embodiment, the central part of a first working chock placed on a first side of the rolling plane comprises, on a first side of the clamping plane, a support member comprising a single cooperating support part with a pair of opposite camber cylinders and framed by two recesses, and, on the second side of the rolling plane, a support member comprising two support parts spaced apart on either side of a single cooperating recess respectively with two pairs of opposite jacks controlled synchronously, the arrangement of the support members and jacks being reversed for the second working chock placed on the other side of the rolling plane.

In addition, the arrangements according to the invention are applicable to a rolling mill comprising means of axial displacement, one with respect to the other, of the intermediate rolls in order to adapt to the width of the product the length of the rolls on which s 'exerts the rolling effort. To this end, in a preferred embodiment, each projecting part, respectively upper or lower of a hydraulic block comprises a central part fixed relative to the cage and two movable lateral parts placed on either side of the part central and axially sliding mounted on the hydraulic block, and each set of bending cylinders, respectively upper or lower, comprises at least one central cylinder bearing on the fixed central part of the projecting part and acting towards the rolling plane, and at least two lateral jacks bearing respectively on the two movable lateral parts of the projecting part and acting on the side opposite to the rolling plane, each chock comprising a central part provided, on each side, of a support member for at least one central cylinder, and two end parts joined on either side of the central part and each provided, on each side of the clamping plane, with a support for a lateral jack mounted on a corresponding movable part of the projecting part.

Other particularly advantageous characteristics, which come within the scope of protection of the invention, will appear during the description which follows of a particular embodiment, given by way of simple example and represented in the appended drawings. Figure 1 shows, in cross section, a rolling mill allowing, according to the invention, the mounting of the rolls in three configurations, respectively quarto (a), sexto (b) and Z.High (c).

Figure 2 shows, on an enlarged scale, the arrangement of the cylinders and their bending means, in the rolling position, in a quarto configuration (a).

Figure 3 shows the arrangement of the cylinders in a sexto configuration (b).

Figure 4 shows the arrangement of the cylinders in a Z.High configuration (c). FIG. 5 shows, on an enlarged scale, the arrangement of the cylinders and their bending means, in the disassembly position in the sexto configuration (b).

Figure 6 shows, in perspective, a type of chock suitable for a large diameter cylinder. Figure 7 shows, in perspective, a type of chock suitable for a medium diameter cylinder.

Figure 8 shows, in perspective, a type of chock usable for a small diameter cylinder, in a Z.High configuration.

Figure 9 and Figure 10 are partial perspective views, respectively, of the positive and negative bending of the working rolls in a quarto configuration.

Figure 11 and Figure 12 are partial perspective views of the cambering means, respectively positive and negative of the cylinders in a sexto configuration, with axial offset of the intermediate cylinders. Figure 13 and Figure 14 are partial perspective views of the bending means, respectively positive and negative of the cylinders in a Z.High configuration, with axial offset of the intermediate cylinders. FIG. 15 shows, in perspective, a hydraulic block with axial offset in one direction or the other, of a part of the camber cylinders.

In Figure 1, there is shown in cross section, the three configurations (a), (b), (c) that can be given to a rolling mill according to the invention.

This rolling mill comprises, as usual, a support cage A comprising two columns connected by a cross member and resting on a foundation block. Each column has two uprights A1, A2 limiting a window A3 in which the chocks of the cylinders are threaded.

In the quarto configuration shown in FIG. 1a, the rolling mill comprises two working rolls C1, C'1 placed on either side of a substantially horizontal rolling plane P1 and bearing, on the opposite side, on two support S, S 'carried, at their ends, by bearings not shown which are housed in chocks S1, S'1 mounted sliding in the windows A3 of each column A, parallel to a clamping plane P2, generally vertical, in which are placed substantially the axes of the cylinders. It is the same, in the embodiment shown in the drawings, for the working rolls C1, C'1 which are also carried by chocks E1, E'1 sliding vertically.

Thus, it is possible, on the one hand, to adjust the spacing, or air gap, between the working rolls C1, C'1 as a function of the gross thickness of the product to be laminated, to allow engagement of the latter. ci and, on the other hand, to exert a clamping force between the rolls for the rolling of the product.

As usual, in the example shown in the drawings, clamping means D are used such as screws or jacks bearing, on one side on the cage, at the top of each window A3 and on the other, on the chocks S1 of the upper support cylinders S, then that the chocks S'1 of the lower support cylinders S bear on the lower part of each window A3, by means of wedging means not shown, the height of which can vary in order to adjust the level of the rolling plane P1. To allow the height adjustments of the cylinders, each chock S1, S'1 of a support cylinder S, S 'is provided with lateral sliding faces S2, S'2 which slide along parallel conjugate guide faces A4, at the clamping plane P2, formed on the internal faces of the two uprights A1, A2 of the column A. The chocks E, E 'of the working rolls C1, C'1 must also slide vertically but they have a narrower width due of the reduced diameter of the working cylinders C1, C'1. This is why, each window A3 of the cage is provided, at the level of the rolling plane P1, with support and guide parts B1, B2 generally called “hydraulic blocks” for the reasons indicated above. Each chock E is therefore slidably mounted along guide faces formed on the ends of parts F, F ′ of the two hydraulic blocks which extend in projection, from the two sides of the window A3, towards the interior of that -this. These projecting parts F, F ′ carry, on the other hand, sets of jacks V, V exerting cambering forces on the chocks E, E ′ of the two working cylinders C1, C ′ 1.

In general, these provisions are well known and do not require a detailed description.

It should be noted, however, that, as shown in each drawing in two half-sections, on either side of the vertical axis, the diameter of each type of cylinder can vary over a certain range because, as indicated more high, it is necessary to periodically rectify, by machining, the external face of the cylinders, the surface quality of which may deteriorate over time. This is the case, in particular, of the working rolls which are in contact with the rolled product. But the other cylinders, intermediate or support, must also be replaced after a certain period of use, by new rectified cylinders.

A rolling installation must therefore be equipped with several copies of cylinders of each type having, in new condition, a determined diameter which can then decrease over a certain range of wear, as and as successive rectifications. Each cage must therefore be equipped with means for clamping and guiding the rollers extending over an adjustment range which depends not only on the variation in thickness of the product but also on the number of rolls and their diameters. As shown in the three views, a, b, c, of FIG. 1, the invention makes it possible to give to the same rolling mill one or the other of three configurations respectively quarto (a), sexto (b) or Z .High (c), keeping the same cage A, the same support cylinders S, S ', the same means D of application of the clamping force, the same hydraulic blocks B1, B2 and the same cambering means V, V ".

Figures 2, 3 and 4 are shown respectively, in cross section and for each configuration (a), (b), (c), the central part of the cage, between the support cylinders.

In the rolling position shown in these figures, the rolls are supported on each other along a common generator, the two working rolls C1, C'1 being simply separated from an air gap corresponding to the thickness to be given to the product to be laminated.

In general, the overall height of all the rolls depends on the configuration of the rolling mill. The height H of the window A3 must therefore be sufficient to allow the penfiiement of all the chocks in the most bulky configuration, that is to say the sexto configuration shown in FIG. 3, and for the maximum diameter of the cylinders of each type.

Usually, the height of the hydraulic blocks B1, B2 which carry the parts F, F 'for guiding the working chocks and the sets V, V "of bending cylinders, depends on the number of cylinders placed between the support cylinders and their However, because these hydraulic blocks B1, B2 are fixed to the uprights A1, A2, on each side of the window B, their height is limited to the space existing between the chocks S1, S'1 of the cylinders of support S, S 'and must therefore be reduced in the quarto configuration for which only two working cylinders C1, C'1 are interposed between the support cylinders S, S'.

Hitherto, therefore, a rolling stand has been provided for a given configuration. The invention, on the other hand, makes it possible to give the same rolling mill one of the three configurations (a), (b), (c) shown in FIG. 1 while retaining the same cage A and the same hydraulic blocks B1, B2 . In addition, thanks to the arrangements which will be described later, the invention makes it possible to give the hydraulic blocks B1, B2, a minimum height (h), valid for all configurations and which, in practice, can be of the same order as the sum of the diameters of the working cylinders C1, C'1 in the quarto configuration, as shown in Figure 2.

This reduction in the height of the hydraulic blocks B1, B2 results in particular from the fact that each of said hydraulic blocks has only two projecting parts F, F 'which carry camber cylinders V, V "acting in the positive direction and in the direction negative, these cylinders being, moreover centered in two vertical planes Q1, Q2 parallel to the clamping plane and symmetrically spaced apart on either side of it. For this, special chocks are used, adapted to the three configurations and type shown, in perspective, in Figures 4, 5 and 6, the mounting of said chocks between the hydraulic blocks being shown in Figures 7 to 12.

As indicated above, the diameters of the rolls can vary over a certain range of wear and the various components of the rolling mill, in particular the cage, the hydraulic blocks and the camber cylinders, are normally adapted to a certain type of roll. . In addition, as the cylinders must be dismantled for maintenance and rectification after use and it is necessary to reduce the downtime of the rolling mill, it is normally equipped with several sets of cylinders allowing the rapid replacement of the cylinders in service by new rectified cylinders.

The working rolls placed on either side of the rolling plan must be replaced more often and, insofar as they wear out in the same way, the two working rolls are usually dismantled and replaced simultaneously.

On the other hand, the support cylinders and the intermediate cylinders, in sexto configuration, can be replaced individually. A rolling stand is therefore associated with means for rapidly replacing the rolls which will be used for the configuration change according to the invention.

In addition each cylinder is disassembled with its chocks and the new cylinders must therefore be equipped in advance, in the workshop, with their two chocks with the bearings.

According to the invention, to allow the choice of a configuration adapted to the nature of the product to be treated, the rolling mill stand shown in FIG. 1 will be equipped, on the one hand, with a certain type of support rollers S, S 'which remains the same in all configurations and, on the other hand, at least two and, preferably, three types of working cylinders having different diameters, respectively large diameter cylinders C1, medium cylinders diameter C2 and cylinders of small diameter C3. In the quarto configuration shown in Figures 1 (a) and 2, two large diameter cylinders C1, C'1 are used as working cylinders. In the sexto configuration shown in FIGS. 1 (b) and 3, two cylinders of medium diameter C2 are used as working cylinders,

C'2 and, as intermediate cylinders, two large diameter cylinders C1, C'1 between each working cylinder C2, C'2 and the support cylinder S,

Corresponding.

In the Z.High configuration shown in FIGS. 1 (c) and 4, small-diameter cylinders C3, C'3 are used as working cylinders and two medium-diameter cylinders C2, C'2 are used as intermediate cylinders between each working cylinder C3, C'3 and the corresponding support cylinder S, S '.

It should be noted that, in the quarto configuration, two medium diameter cylinders C2, C'2 could also be used as working cylinders.

In order not to complicate the drawings, the lateral support means associated, as is known, with the working rolls C3, C'3 in the Z.High configuration, have not been shown in FIGS. 1, 4, 8 , 13, 14.

According to one of the characteristics of the invention, the configuration change can be carried out very quickly, for example by using a replacement system of known type in which the cylinders are disassembled and replaced by displacement parallel to their axis, each chock being provided with rollers rolling on rails provided on the cage, at a disassembly level for which the cylinders are spaced from each other so that their surface is not deteriorated . Thus, to pass from the quarto configuration of FIG. 1 (a) to the sexto configuration of FIG. 1 (b), the support cylinders S, S'4 which can, moreover, remain in the cage, are all first, upwards and downwards, substantially up to the levels which they must occupy in sexto configuration, and the working cylinders C1, C'1 are placed at their disassembly level. It is advantageous to use a replacement device comprising two compartments, respectively an empty compartment in which the two working cylinders C1, C'1 previously in service are transferred, and a compartment in which two parts have been placed. medium diameter cylinders C2, C'2 at the working cylinders and, on the other hand, at the intermediate cylinders, two large diameter cylinders C1, C'1, of the same type as those which have just been removed . All these cylinders were equipped in advance with their chocks. After placing the new cylinders in line with the rails, they are inserted into the cage in the service position and the support cylinders can be tightened. In known manner, to facilitate disassembly and replacement, the cylinders and their chocks can be placed in cassettes comprising either two working cylinders C1, C'1, or a set of two working cylinders and two intermediate cylinders, for the sexto configuration. Insofar as the change in configuration is justified by a change in production range, we can have several sets of cylinders in stock and introduce cylinders into the cage having, for example, a surface quality better suited to the new product to be rolled. On the other hand, as indicated above, for the same type of cylinders, the diameters can vary over a certain range.

For the configuration change to be particularly rapid, it is preferable that the support cylinders remain in place in the cage. However, in some cases, it may be advantageous to choose, from the set of support cylinders available, cylinders fairly large in diameter for the quarto configuration and cylinders of the same type but slightly smaller in diameter in sexto configuration in order to reduce the overall size of the cylinders.

According to another particularly advantageous characteristic of the invention, which will be described in more detail below, the two cylinders of the same type, respectively of large diameter, medium diameter or small diameter, can be equipped with the same chocks which are arranged in such a way that, by simple turning, they can equip either an upper cylinder or a lower cylinder. We thus benefit from a modular arrangement allowing to have in stock, simply, three types of chocks, respectively for large diameters, for medium diameters and for small diameters and to equip on demand new cylinders by orienting the chocks according to the arrangement they must occupy, either above or below the rolling plane. Figures 6, 7 and 8 show, respectively, the three types of chocks usable for a large diameter cylinder (Figure 6) of medium diameter (Figure 7) or small diameter (Figure 8).

In this preferred embodiment, shown in the drawings, each chock consists of three adjoining parts, respectively a central part and two end parts.

Thus, Figure 6 shows a chock E1 for a large diameter cylinder, comprising a central part 1 on the sides of which are fixed two end parts, respectively 2a, 2b. Figure 6 shows a chock for a lower cylinder but an upper chock would be made in the same way, by turning it in block of 180 ° to mount it on an upper cylinder.

As is known, each cylinder is provided at each end with a journal which rotates in a centering bearing housed in a housing constituting the chock on which the support members of the camber cylinders and the sliding faces are formed. side. In the invention, the bearing (not shown) is housed in the central part 1 of the chock and each end part 2a, 2b consists of a flange provided with a circular orifice 25 for the passage of the journal. The central part 1 of the chock is provided, as usual with support members 11, 12 for the cambering jacks. In the example shown, these support members form ears projecting from the sides 15 of the chock on which the sliding faces thereof are formed, which are parallel to the clamping plane P2 (FIG. 2).

However, the arrangement of the support members is particular. Indeed, on one side of the chock, for example the right side in Figure 6, the support member 12 has a central recess 14 between two spaced support parts 12a, 12b. On the other hand, on the other side of the clamping plane, the support member 11 comprises a single support part between two recesses 13a, 13b. In addition, the two support members 11, 12 are offset in height relative to the axis x'x of the pin threaded in the chock so that, in the working position shown in Figure 2, these bodies support are placed substantially at the rolling plane P1.

Similarly, the two flanges constituting the end parts 2a, 2b fixed on either side of the central part 1 of the chock, each carry two support members, respectively 21a, 22a, on the front flange 2a and 21 b, 22b on the rear flange 2b, which are offset in height relative to the axis x'x of the chock. In addition, each flange 2a, 2b is provided with a projecting part forming a tenon 23 extending horizontally and capable of engaging in a conjugate groove of the same section, formed on the side of the central part 1 of the poisons and forms a mortise. Thus, it is possible, by reversing the flanges 2a, 2b relative to the central part 1, to place the support members, either on two planes spaced apart in height, as shown in FIG. 6, or in the same plane, these support planes being offset in height on one side or the other of the axis x'x of the chock.

Thanks to these provisions, a chock of the type shown in Figure 6, can be arranged in various ways, by turning, either the whole chock, or only the end parts. First of all, by turning 180 °, around the axis x'x, of the whole chock, this can be mounted, either on an upper working cylinder C1, or a working cylinder lower C'1, in a quarto configuration.

In addition, by turning only the end parts 2a, 2b relative to the central part 1, the same chock can be adapted to the sexto configuration while retaining practically the same spacing of the support members relative to the rolling plane P1.

Figures 9 and 10 show the arrangement and use of two chocks of the type of Figure 6, respectively for the positive bending and for the negative bending of the working rolls, in the quarto configuration.

As shown in FIG. 2, the respectively positive and negative bending of the cylinders is carried out by two sets of cylinders respectively upper V and lower V ", which are centered in two planes Q1, Q2 parallel to the clamping plane P2. As usual, these bending jacks are supported on projecting parts F, F 'of the two hydraulic blocks B1, B2 fixed on the two sides of the window A3.

However, for the implementation of the invention, it is particularly advantageous to use the particular arrangement of chocks and hydraulic blocks shown in the drawings, in which, on the one hand, each hydraulic block has only two projecting parts spaced apart on either side of the rolling plane, and, on the other hand, the support elements of the chocks can be placed, by simple inversion thereof, either between the two projecting parts, substantially at the level of the rolling plan, above and below it. Such an arrangement makes it possible, in fact, to reduce the overall height of the hydraulic blocks, by defining only three support levels of the chocks which remain the same in all configurations, respectively a central support level of the corresponding working chocks substantially at the rolling plane and two levels, respectively upper and lower, for supporting the intermediate cylinders placed respectively above and below protruding parts of the hydraulic blocks.

Figures 9 and 10 are partial perspective views showing, in a quarto configuration, the arrangement of the working chocks as well as the camber cylinders, respectively in the positive direction in Figure 9 and in the negative direction in the figure 10.

In this quarto configuration, large diameter cylinders are used associated with chocks of the type shown in FIG. 6 and it can be seen that, in a particularly advantageous manner, the same chocks can, by simple turning, serve as top chock E1, or bottom chock E'1, each chock being symmetrical with respect to a median plane perpendicular to the axis x'x of the journal.

Each hydraulic block B1, B2 comprises a solid part 5 fixed on the internal face of the corresponding upright A1, A2 of column A and carrying two parts 6, 6 ′ placed symmetrically with respect to the rolling plane P1 and which extend in projection towards the inside of the window up to an end 61, 61 ′ carrying a vertical face for guiding the corresponding chock E1, E'1. On each projecting part 6, 6 ′, the jacks are arranged in two groups, respectively a central group of jacks acting towards the rolling plane P1 and a group of lateral jacks placed on either side of the central group and acting on the side opposite to the rolling plane P1. These two groups of jacks are placed, respectively, in a central part 62 and two lateral parts 63, 64 of the projecting part 6 and are centered on the same plane Q1, Q2 parallel to the clamping plane P2, on the one hand and on the other. other of it.

For the reasons indicated below, in the preferred embodiment shown in the figures, the central part 62 is integral with the solid part 5 fixed on the corresponding amount of the cage while the two lateral parts 63, 64 can slide axially in grooves 51, 51 'formed on this part 5.

In the preferred embodiment shown in the figures, the central part 62 of each projecting part 6, 6 ′ carries three jacks all acting towards the rolling plane but controlled separately, some for positive bending and the others for bending negative. On the other hand, the jacks placed in the lateral parts 63, 64 act on the side opposite to the rolling plane, only for positive bending.

Figure 9 is a partial perspective view showing only the positive camber cylinders. As indicated above, the upper chock E1 placed above the rolling plane comprises a central part 1 provided with two support members 11, 12, projecting on either side of the sides 15 of the chock, respectively on the right (11) and on the left (12) in the figure, these support members being placed at a level corresponding, substantially, to that of rolling plan. On the other hand, as shown in Figure 6, the two support members extending on either side of the central part 1 of the chock have profiles in inverted slots, one comprising, a recess central framed by two support parts while the other has a central support part framed by two recesses.

It should be noted that the arrangement in FIG. 6 corresponds to a lower chock E'1, the upper chock E1 being turned upside down by 180 °.

Thus, in the assembly of FIG. 9, the central part 1 of the upper chock E1 placed above the rolling plane comprises, on the right, a central support part 11 framed by two recesses 13a, 13b while the 'support ear 12 placed on the left side and not visible in the figure, has a central recess framed by two support parts.

On the other hand, the lower chock E'1 has, on the right side, two support parts 11 'a, 11'b framing a central recess 13', the arrangement being reversed on the left side. Thus, the support members facing each other have overlapping niche profiles.

In this way, the positive bending of the upper chock E1 can be controlled by a central jack V'1 mounted in the central part of the corresponding projecting part 6 'and crossing the rolling plane P1 to exert a positive bending effort on the central support part 11 of the upper chock 1.

Conversely, the positive arching of the lower chock E'1 is carried out, on the right side of the figure, by two jacks V1a, V1 b mounted in the central part of the upper projecting part 6 and acting, in the positive direction, on the support parts 1a, 11'b of the lower chock 1a between which passes the cylinder V'1 of positive bending of the upper chock E1.

In this arrangement, a positive bending force can also be exerted by lateral jacks, respectively V3a, V3b on the right side and V4a, V4b on the left side, mounted in the lateral parts 63, 64 of the projecting part 6 and acting in the positive direction, that is to say on the side opposite to the rolling plane, on the support members of the two end parts 2a, 2b of the chock, respectively 21a, 21b on the right side and 22a , 22b on the left side. Of course, the arrangement is reversed for the lower chock E'1.

Thus, the positive bending forces can be applied by all of the jacks and at two levels on each working chock in the quarto configuration, which makes it possible to have a greater bending force.

For negative bending, the cylinders acting towards the rolling plane are used and mounted in the central part 62 of each projecting part 6, 6 ′ as shown in FIG. 10. In general, the central group of cylinders cooperating with the central parts 1, the of the two chocks E1, E'1, consists of at least two pairs of opposite cylinders acting, respectively in the positive direction and in the negative direction on the two faces of the member corresponding support of the chock. As we have seen, in the preferred embodiment shown in Figures 9 and 10, the central part 1 of the upper chock E1 is provided with a central support member 11 on which is supported, in the direction negative, a central cylinder V1 mounted in the central part 62 of the upper projecting part 6 of the hydraulic block and, consequently, opposite to the positive cambering cylinder V'1 of the same chock, which is placed on the other side of the rolling plane and crosses it.

Conversely, the negative arching of the lower chock E'1 is carried out, on the right side of the figure, by two jacks V'1 a and V'1 mounted in the lower projecting part 6 ', which exert bending forces directed towards the rolling plane on the support parts 11 'a, 11'b passing on either side of the cylinder V'1 of positive bending of the upper chock E1, and are opposite to the cylinders V1a , V1 b of positive bending of the same lower chock E'1, mounted in the upper projecting part 6.

Of course, the arrangement is reversed on the hydraulic block B2 placed to the left of the clamping plane and whose upper protruding part 6 carries, in its central part two cylinders for negative cambering of the upper chock E1 and a central cambering cylinder positive of the lower chock E'1, the arrangement being reversed on the central part 62 'of the lower projecting part 6' of the hydraulic block B2. To move from the quarto configuration to the sexto configuration shown in FIG. 3 and, partially, in perspective in FIGS. 11 and 12, intermediate cylinders of the same type as the working cylinders C1, C are used according to the invention '1 of the quarto configuration, which are therefore spaced from one another in order to set up working cylinders of medium diameter C2, C'2.

The ends 61 of the two projecting parts 6, 6 ′ then serve to guide the working chocks E2, E'2. Since, according to one of the characteristics of the invention, the height of the hydraulic blocks B1, B2 must be limited to that which is necessary for the quarto configuration, the guiding of the intermediate chocks E1, E'1, in the configuration sexto, is provided by two support pieces B3 bearing laterally on the uprights A1, A2 which limit the sides of the window A3 and on which are provided vertical guide faces (f) parallel to the clamping plane P2.

In this configuration, the hydraulic blocks B1, B2 further define three support levels for the bending cylinders, respectively a central level H1 corresponding substantially to that of the rolling plane P1 and two levels, respectively upper H2 and lower H'2 placed at - above and below the protruding parts 6, 6 '. The two sets of cylinders V, V placed in these projecting parts 6, 6 ′ remain the same but their functions are different. As in the quarto configuration described above, the central cylinders V1, V2, V'1, V'2 which act at the central level H1, in the direction of the rolling plane P1 will serve for the positive and negative bending of the working rolls C2 , C'2 while the lateral cylinders V3, V4, V'3, V'4 which act at levels H2 and H'2, towards the side opposite to the rolling plane, serve for the positive bending of the intermediate cylinders C1, C ' 1.

It is necessary, however, for the lateral faces 15 of the intermediate chocks E1, E'1 to slide between the guide faces (f) formed on the support pieces B3, B'3. For this, the end parts 2a, 2b of each chock E1, E'1 are turned 180 ° relative to the central part 1. This turning can be carried out easily because, as indicated, the end parts 2a , 2b of the chock are provided with horizontal pins 23 which engage in corresponding grooves in the central part 1.

Compared to the arrangement shown in FIG. 6, after turning the end portions 2a, 2b, the support members 21, 22 change sides, coming to be placed substantially in alignment with the support members 11, 12 of the central part 1. After lifting of the cylinder C1, the support members 21, 22 of the end parts return to substantially the same level H2 as in the quarto configuration. As shown in Figure 11, the cylinders V3a, V3b placed on the right side, therefore exert positive bending forces on the support members 22a, 22b of the two end parts 2a, 2b of the upper intermediate chock E1. Similarly, the two support members 21 placed on the left after turning over cooperate with the lateral jacks V4 for the positive bending of the intermediate cylinder C1. The arrangement is the same, in reverse, for the chock E'1 of the lower intermediate cylinder C'1.

As shown in FIG. 7, the chocks of the medium diameter cylinders which, in the sexto configuration, constitute the working cylinders C2, C'2, are similar to the chocks E1, E'1 of the large diameter cylinders and therefore comprise a central part 10 on which are joined two end parts 20a, 20b. Of course, the bearings, not shown in the figures, are adapted to the diameter of the trunnions of cylinders C2, C'2 of medium diameter, but the spacing between the lateral faces 150 of the working chocks E2, E'2 is the same that the spacing between the lateral faces 15 of the chocks E1 of large diameter. The sliding faces 150 of the chocks E2, E'2 can therefore slide along the same guide faces 61 formed at the ends of the projecting parts 6, 6 'of the two hydraulic blocks B1, B2.

However, to allow mounting in the Z.High configuration in the manner which will be described later, the sliding faces 150 of a chock E2 of medium diameter, extend only over part of the height of the chock, the latter being provided, on the remaining part, with two lateral sliding faces 16 whose spacing is reduced.

On the other hand, as for the chocks of the intermediate cylinders E1, E'1, the end parts 20a, 20b are fixed on the central part 10 so that their support members 210, 220 are at the same level as the support members 110, 120 of the central part 10.

FIGS. 11 and 12 show, in perspective, the arrangement of the camber cylinders, to the right of the clamping plane, respectively in the positive direction in FIG. 11 and in the negative direction in FIG. 12.

As can be seen in FIGS. 3 and 11, the upper working chock E2 is turned upside down with respect to FIG. 7, so that its support members 210, 220 are located substantially at the rolling plane P2 , the sliding faces 150 extending upward to slide between the ends 61 of the upper protruding parts 6. As in the quarto configuration, the positive bending of the working cylinder C2 is carried out, on the right of the figure, by the central cylinder V'1 which is mounted on the other side of the rolling plane and passes through it to be applied to the support member 110 of the central part 10. Conversely, the positive camber of the 'lower chock E'2 is made, on the right, by the two cylinders V1a, V1 b which pass through the recesses made on either side of the central support member 110 to be applied to the parts of support 110'a, 110'b of the lower chock E'2, extending on either side of the central jack V '1. Of course, the arrangement is symmetrical for the left side.

In this sexto configuration, the support members 210a, 210b of the end portions 20a, 20b of the working chock E2 are therefore not used for bending but simply carry rollers G which, conventionally, roll on rails R set up for disassembly, these rollers G being, thus, sufficiently spaced to ensure, in good conditions, the sliding maintenance of the chock.

According to the invention, the medium diameter cylinders C2, C'2 provided with their chocks E2, E'2 can be used as intermediate cylinders in a sexto configuration of type Z.High, as shown in view (c) in Figure 1, as well as in Figures 4, 13 and 14.

In this case, working cylinders C3, C'3 of small diameter are used which are associated with chocks E3, E'3 of the type shown in FIG. 8. Such a chock still preferably comprises three contiguous parts, respectively a central part 3 and two end parts

4a, 4b. The central part 3 carries the centering bearings of the cylinder and can have a fairly reduced height, the journals of a working cylinder having a small diameter in the case of a Z.High assembly.

As before, this central part 3 is provided, on either side of the axis x'x of the bearing, with two sliding faces 35, the spacing of which corresponds to that of the facing ends 61 of the projecting parts 6 two hydraulic blocks B1, B2 and two support members 31, 32 which project from the plane of the sliding faces 35.

In FIG. 8, the chock is shown in its position E3 corresponding to an upper working cylinder and it therefore comprises a central support part 31 which extends only over part of the length of the chock and is surrounded by two recesses 33a, 33b. On the other hand, on the left side, the support member 32 comprises two parts spaced on either side of a central recess 34.

Thus, as shown in FIGS. 13 and 14, the chock E3 of the upper working cylinder C3 is provided, on the right of the figure, with a support part 31 which extends substantially at the level of the rolling plane P2 and passes between the rods of the two cylinders V1, V'1 housed respectively in the projecting parts 6, 6 ', the lower cylinder V'1 acting in the positive direction (FIG. 13) and the upper cylinder V1 in the negative direction ( figure 14). Conversely, the chock E'3 of the lower cylinder C'3 is provided, on the right of the figure, with two support parts 31 'a, 31' b on which act two pairs of opposite jacks, respectively, the upper jacks V1a, V1b in the positive direction (Figure 13) and the lower cylinders V'1 a, V'1b in the negative direction (Figure 14).

As before, the arrangement of the jacks and support members on the left of the figure is deduced from that on the right by a central symmetry.

As shown in FIG. 4, in this Z.High configuration, the medium diameter cylinders C2, C'2 are used as intermediate cylinders, which are therefore spaced apart from one another to set up the small diameter cylinders C3 , C'3 and whose chocks E2, E'2 are turned over as a whole with respect to the sext arrangement in FIG. 3. In this way the organs support 220, 210 of the end portions 20a, 20b of the upper chock E2 are located above the upper level of the protruding parts 6 and therefore cooperate with the lateral jacks V3, V4 of the hydraulic blocks B1, B2 , respectively on the right and on the left of the figure, the arrangement being symmetrical for the lower intermediate chock E'2.

In this Z.High arrangement as in the sexting arrangement described above, the invention makes it possible to exert positive cambering forces on the intermediate cylinders.

These sliding faces 35 which extend above or below the support members 31, 32 are formed on two vertical legs 36 of the central part 3 of the chock E3 whose internal sides 37 form faces guide for the intermediate chock E2, as will be seen below.

As indicated, the sliding faces 150 of a chock of medium diameter E2 extend only over part of the height thereof and are extended by tighter sliding faces 16 which, in the assembly Z.High slide along the internal faces 37 of the legs 36 of the central part 3 of the chock E3 of the small diameter cylinder C3. Thus, as shown in FIG. 4, the guide faces 61 formed at the ends of the projecting parts 6, 6 ′ serve, over part of their height, for guiding the working chocks E3, E'3 and, on the part remaining, to the guide of the intermediate chocks E2, E'2 which are also guided, by their sliding faces 16, on the legs 36 of the working chocks E3, E'3.

The arrangements which have just been described also allow an axial offset of the intermediate cylinders, in the sexto or Z.High configurations.

In fact, as shown in FIG. 15, the two lateral parts 63, 64 of a projecting part 6 are slidably mounted axially in a groove 51 of the solid part 5 of the hydraulic block B, the central part 62 remaining fixed. In this way, the central cylinders V2, V'2 which act towards the rolling plane B2 remain axially fixed but the lateral cylinders, respectively upper V3, V4 and lower V'34, V'4 mounted, on both sides of the clamping plane, on the moving parts 63, 64 of the pieces in projection 6, 6 'can move axially with the chocks of the corresponding cylinder.

This movement can be carried out in both directions, as shown by the three perspective views (a) (b) (c) of Figure 15. Figure 11, for example, corresponds to the view (c) of Figure 15 with a rearward offset for the upper intermediate cylinder C1 and forwards for the lower intermediate cylinder C'1. FIG. 12, on the other hand, corresponds to view (a) of FIG. 15 with an offset towards the front of the upper intermediate cylinder C1 and towards the rear of the lower intermediate cylinder C'1. In view (b) of Figure 15, which corresponds to the quarto configuration shown in Figures 9 and 10, there is no axial offset of the cylinders, the moving parts 63, 64 being symmetrically spaced apart from the central part 62, as shown in view (b) of FIG. 15. Thus, in the sexto or Z.High configurations, the intermediate cylinders C1, C'1 or C2, C'2 can be moved axially with their chocks and positive camber cylinders V3, V4, V'3, V'4. On the other hand, in the three configurations, the chocks of the working rolls remain centered in the median plane of the hydraulic blocks B1, B2, as do the central jacks V1, V2, V'1, V'2.

As usual, in each configuration, the cylinders can be dismantled and replaced by displacement parallel to their axis, by rolling on removable or eclipsable rails.

These rails may consist, for example, of profiles 7 slidably mounted on grooves 52 parallel to the axes of the cylinders and formed on each side of the clamping plane, on the solid parts 5 of the two hydraulic blocks B1, B2.

As shown in FIG. 15, these grooves can be formed on four levels, on either side of each projecting part 6, 6 ′, to allow the mounting of four pairs of rails, respectively upper 71, 72 and lower 71 ', 72'.

As already indicated, the support members of the end parts 2, 20, 30, of each type of chock E1, E2, E3 carry rollers G axially spaced apart. By way of example, FIG. 5 shows the cylinders in the disassembly position, for the sexto configuration. The two upper cylinders, respectively working C2 and intermediate C1 can be lifted by their positive camber cylinders, a little above the levels of the rails to allow the establishment of these inside the cage, by axial sliding on the grooves 52. The cylinders can then be lowered so that their rollers G rest on the rails 71, 72.

As shown in FIG. 3, in the rolling position, the rollers mounted at the ends of the chock support members E'2, E'1 of the two lower cylinders, respectively working C'2 and intermediate C'1, are located , in any case, above the level of the lower rails 72 ′ 71 ′ which can therefore be put in place, by axial sliding, for the disassembly of the cylinders. If the lower support cylinder S 'is lowered by means of a not shown wedging means, the two cylinders C'1, C'2 descend with it and their rollers come to rest on the respective rails 72', 71 'to allow disassembly and reassembly of the cylinders by axial displacement.

The profiles 7 constituting the rails could also be provided with eclipsable support parts to allow adjustments of the levels of the chocks, during rolling.

The arrangements which have just been described therefore make it possible to easily and quickly change the configuration of a rolling mill to pass, according to the nature of the product to be laminated, from a quarto configuration to a sexto or Z.High configuration and vice versa, by using only three types of cylinders having, respectively, a large, a medium and a small diameter and retaining all the essential organs of the rolling mill, that is to say the cage A, the clamping means D, and the hydraulic blocks B1 , B2 carrying the cylinders level adjustment cylinders. As indicated, because the same hydraulic blocks are used in the three configurations, the height of the latter can be limited, the guidance being provided by simple attached legs B3 which can be fixed removably on the chocks of the support cylinders S, S '.

The height H of the window A3 must, however, correspond to the total height of the chocks in the sexto configuration and this is why it is advantageous, in the quarto and Z.High configurations represented. respectively in views (a) and (c) of FIG. 1, of having, at the ends of each window A3, two solid parts M, M 'forming shims of thickness interposed, on the one hand between the clamping means D and the chocks S1 of the upper support cylinder and on the other hand between the lower part of each window A3 and the wedging means (not shown) on which the lower chocks of support S'1 bear. This avoids increasing the stroke of the clamping cylinders D.

However, the invention is not limited to the details of the embodiment which has just been described by way of a preferred example and, on the contrary, covers variants or equivalent means ensuring the same functions and remaining within the scope of the protection claimed. .

For example, in the embodiment which has just been described, the positive and negative bending of the rolls is ensured by pairs of opposite single-acting cylinders acting, respectively, towards the rolling plane and on the side opposite to it . In fact, such jacks are simply applied to the support members of the chocks and release them when they are retracted. It would, however, be possible to use double-acting cylinders having a rod detachably fixed on the support member of the chock and thus making it possible to ensure the negative and positive bending of the corresponding cylinder.

On the other hand, in the arrangements described above, the support members of the chocks, sometimes called "ears" extend in projection relative to the sliding faces formed on each side of the chock. The invention could, however, adapt to other known arrangements. For example, the bending forces could be applied, on each side of the chock, to an intermediate piece engaging in a groove formed in the corresponding sliding face, this groove being offset with respect to the axis of the chock so as to allow two positions thereof, by simple inversion.

Furthermore, the invention does not necessarily apply to a new installation but has, on the contrary, great advantages for the modernization of an existing installation.

In the case of a new installation, as described above, three types of cylinders will be chosen having respectively a large, a medium and a small diameter and making it possible to process a very wide range of products, the dimensions of the cage being determined according to the sexto configuration which has the maximum bulk.

However, the invention also makes it possible, within the framework of a modernization, to extend the range of products which can be treated in an existing rolling mill while retaining the same cage, the latter being simply adapted, for example for placing there bending hydraulic blocks. For example, an existing quarto cage having a window height too low for a conventional sexto configuration, could be modernized, thanks to the invention, by making it possible to pass from a quarto configuration to a Z.High configuration or vice versa, the range of rollable products thus being extended.

Furthermore, it is usually preferred to use cages symmetrical with respect to the rolling plane but, in certain cases, the arrangements which have just been described would allow asymmetrical arrangements to be made.

In fact, since the same hydraulic blocks can be kept in all configurations, it would be possible, for example, to produce a quarto assembly with a working cylinder of fairly large diameter on one side of the rolling plane and a Z.High assembly with a working cylinder of smaller diameter, on the other side of the rolling plane.

The invention therefore gives numerous possibilities making it possible to respond very flexibly to a change in the characteristics of the products to be laminated.

On the other hand, the modular construction which has been described has the advantage of using only three types of chocks for all configurations, since each chock is provided, on either side of the clamping plane, d 'support members with inverted profiles and can be used on either side of the rolling plane.

It would be possible, however, to produce chocks having the same support members on either side of the clamping plane, but with inverted niche profiles above and below the rolling plane. For example, an upper chock could have, on each side, a single support part placed between two recesses, the chock lower having, conversely, support members comprising, on each side two support parts framing a single recess. Such an arrangement would also make it possible to produce hydraulic blocks of reduced height having a C-shaped profile with two protruding parts for supporting camber cylinders acting on support members placed substantially at the rolling plane by crossing it in the meaning of positive cambering.

The reference signs inserted after the technical characteristics mentioned in the claims are intended only to facilitate the understanding of the latter and in no way limit their scope.

Claims

CLAIMS 1. Method for changing the configuration of a rolling mill comprising:

- a holding cage (A) having two spaced apart columns each provided with a window (A3) having two opposite sides (A1, A2),

- a set of superimposed cylinders with substantially parallel axes, comprising at least two working rolls, respectively upper (C1) and lower (C'1), placed on either side of a substantially horizontal rolling plane (P1) of a product to be laminated and two support cylinders (S), respectively upper and lower,

- Each cylinder (C1, C'1) having two ends rotatably mounted, each on a bearing carried by a chock (E) slidably mounted, parallel to a clamping plane (P2), along sliding faces cooperating with corresponding guide faces provided on the two sides of the corresponding window (A3) of the cage,

means (D) for applying a clamping force between the chocks (S1, S'1) of the support cylinders (S, S '),

- means for applying vertical bending forces comprising, on each side of the clamping plane (P2), two sets (B, V) of hydraulic bending cylinders, at least two respectively upper working cylinders (C1) and lower (C'1),

- said cambering cylinders (V, V) cooperating with support members formed on the sides of the chocks (E) of said cylinders, on either side of the clamping plane (P2), characterized in that the at least two types of working rolls are produced having, apart from a range of wear, at least two different diameters, respectively a larger and a smaller diameter and that, while keeping the same cage (A), the same means (D, B, V) application of clamping and cambering forces and the same type of support rolls (S, S '), the rolling mill is changed from a quarto configuration to a sexto configuration and vice versa, by changing the arrangement of the cylinders interposed between the support cylinders (S, S '), the cylinders of larger diameter (C1, C'1) being used, in the quarto configuration as working cylinders and, in the sexto configuration, as intermediate cylinders interposed respectively between each support cylinder (S, S ') remained in place and a smaller diameter cylinder (C2, C'2) used as a working cylinder.

2. Method according to claim 1 for changing the configuration of a rolling mill, characterized in that three types of working rolls are produced (C1, C'1) C2, C'2) (C3, C'3 ) having respectively a large, a medium and a small diameter and that, while keeping the same cage (A), the same means (D, B, V) of application of the tightening and bending forces and the same type of cylinders support (S, S '), and by changing the arrangement of the rolls interposed between the support rolls, the rolling mill is given one or the other of at least three configurations, respectively, at least one quarto configuration in which large (C1) or medium (C2) diameter cylinders are used as working cylinders, a sexto configuration in which medium diameter (C2) cylinders are used as working cylinders and large diameter (C1) cylinders are used used as intermediate cylinders, between each medium working cylinder diameter (C2) and a support cylinder (S), and a sexto configuration of type Z.High, in which the small diameter cylinders (C3) are used as working cylinders and the medium diameter cylinders (C2) are used as intermediate cylinders between each small diameter working cylinder (C3) and a support cylinder (S).

3. Method according to one of claims 1 and 2, characterized in that the bending of the working rolls is carried out, in the positive direction of spacing of the chocks and in the negative direction of approximation, using, on the one hand and on the other side of the rolling plane (P1) and on each side of the clamping plane (P2), at least two pairs of single-acting cylinders (V1, V'1) (V'1 a, V'1 b) acting on large diameter working cylinders (C1, C1) in the quarto configuration, on medium diameter working cylinders (C2, C'2) in the sexto configuration and on small diameter working cylinders (C3, C '3) in the Z.High configuration.

4. Method according to one of claims 1 to 3, characterized in that one uses, on either side of the rolling plane (P1) and on each side of the clamping plane (P1), at least a pair of single-acting cylinders (V3, V'3) acting in the positive direction on the large-diameter working cylinders (C1, C'1) in the quarto configuration, on the same large diameter cylinders (C1, C'1) serving as intermediate cylinders in the sexto configuration and on medium diameter cylinders (C2, C'2) in the Z.High configuration.

5. Method according to one of the preceding claims, characterized in that, during a change of configuration, the support cylinders (S, S ') remain in place in the cage (A).

6. Method according to one of claims 1 to 4, wherein, for each type of cylinders, there are several pairs of cylinders, respectively of support or work, having slightly different diameters, characterized in that, for in a quarto configuration, a pair of support cylinders (S, S ') is placed in the cage having a diameter slightly larger than that of the support cylinders used for a sexto or Z-High configuration.

7. Rolling mill comprising: - a holding cage (A) having two spaced apart columns each provided with a window (A3) having two opposite sides (A1, A2),

- a set of superimposed cylinders with substantially parallel axes, comprising at least two working rolls, respectively upper and lower, placed on either side of a substantially horizontal rolling plane (Pl) of a product to be laminated and two support cylinders, respectively upper (S) and lower (S '),

- Each cylinder having two ends rotatably mounted, each on a bearing carried by a chock (E) slidably mounted, parallel to a clamping plane (P2), along sliding faces cooperating with corresponding guide faces formed on the two sides of the corresponding window (A3) of the cage,

means (D) for applying a clamping force between the chocks (S1, S'1) of the support cylinders (S, S '),

means (B, V) for applying vertical bending forces comprising, on each side of the clamping plane (P2), two assemblies (V,

V) hydraulic camber cylinders, at least two working cylinders, respectively upper and lower,

- said cambering cylinders (V, V) cooperating with support members formed on the sides of each chock, on either side of the clamping plane (P2), characterized in that it is equipped with at least two pairs of interchangeable cylinders having at least two different diameters, respectively, a larger and a smaller diameter, said cylinders being usable as working cylinders inside the same stand (A), in at least two configurations of the rolling mill, respectively a quarto configuration in which the two cylinders of larger diameter (C1, C'1) are used as working rolls arranged on each side of the rolling plane ( P1), between the product and the corresponding support cylinder (S, S ') and a sext configuration in which the two smaller diameter cylinders (C2, C'2) are used as working cylinders arranged, respectively, of each side of the rolling plane (P1) and the larger diameter cylinders (C1, C'1) are used as intermediate cylinders arranged, respectively, between each working cylinder of smaller diameter tre and the corresponding support cylinder (S, S '), retaining, in both configurations, the same cage (A), the same type of support cylinders (S, S') and the same means (D, B , V, V) application of clamping and cambering forces.

8. A rolling mill according to claim 7, characterized in that it is equipped with at least two pairs of cylinders, respectively of larger and smaller diameter, usable inside the same cage (A) in two rolling mill configurations, respectively a quarto configuration in which the larger diameter cylinders (C1, C'1) are used as working rolls and a Z.High type sexto configuration in which a larger diameter cylinder (C1, C'1) is used as an intermediate cylinder between each support cylinder (S, S ') and a smaller diameter cylinder (C3, C'3) used as a working cylinder and associated with lateral support means.

9. Rolling mill according to one of claims 7 and 8, characterized in that it is equipped with at least three pairs of rolls having respectively a large, a medium and a small diameter and usable as working rolls inside a single cage, in at least three configurations of the rolling mill, respectively at least one quarto configuration in which the large (C1, C'1) or medium diameter (C2, C'2) cylinders are used as work, a sext configuration in which medium diameter cylinders are used as working cylinders and large diameter cylinders (C1, C'1) are used as intermediate cylinders, between each medium diameter working cylinder (C2, C'2) and a support cylinder (S, S '), and a Z.High type sext configuration, in which the small diameter cylinders (C3, C'3) are used as working cylinders associated with lateral support means and the larger diameter cylinders (C1, C'1 ) or medium diameter (C2, C'2) are used as intermediate cylinders between each small diameter working cylinder (C3, C'3) and a support cylinder (S, S ').

10. Rolling mill according to one of claims 7, 8 and 9, characterized in that, for the change of configuration, the rolls remain equipped with their chocks (E) and that the support members (11, 12) of the chocks (E1, E'1), at least cylinders of larger diameter (C1, C'1)), are offset in height relative to the axis of rotation (x'x) of the cylinder, so that, after displacement in height of a cylinder of larger diameter (C1) and 180 ° inversion of its chocks (E1) around the axis, the support members (11, 12) thereof are located substantially at same level with respect to the rolling plane (P1), respectively in the quarto configuration and in the sexto configuration, and that the same camber cylinders (V1, V2) act, at least in the positive direction on said chocks (E1) placed , respectively, in the working position in the quarto configuration and, after turning over, in the intermediate position in the sexto configuration .

11. Rolling mill according to one of claims 7 to 10, characterized in that, on each side of the clamping plane (P2), the camber cylinders, respectively upper (V) and lower (V), are housed on one side and on the other side of the rolling plane (P1), in two projecting parts, respectively upper (6) and lower (6 '), formed on a hydraulic block (B1, B2) fixed on each side of the corresponding window (A3 ) from the cage.

12. Rolling mill according to claim 11, characterized in that each projecting part (6, 6 ') of a hydraulic block (B1, B2) extends, towards the inside of the window (A3), up to '' to a guide face (61) parallel to the clamping plane and cooperating, in the quarto and sexto configuration, with a sliding face (15) of the corresponding chock (E1, E2) of a working cylinder (C1, C2).

13. A rolling mill according to claim 12, characterized in that, in the sexto configuration, the sliding faces (15) of larger diameter chocks (E1, E'1) serving as intermediate chocks, cooperate with faces of guide (f) provided on support parts (B3) removably mounted inside the corresponding window (A3) of the cage (A), respectively, above and below the two projecting parts (6 , 6 ') of the hydraulic block (B1, B2).

14. Rolling mill according to claim 13, characterized in that the support parts (B3, B'3) of the guide faces (f) of the intermediate chocks (E1, E'1), in the sexto configuration, are legs removably attached to the chocks (S1, S'1) of the two support cylinders (S, S ').

15. A rolling mill according to claim 11, characterized in that, on each side of the clamping plane (P2), the two projecting parts, respectively upper (6) and lower (6 '), formed, on the one hand and on the other. other from the rolling plane (P1) on the corresponding hydraulic block (B1, B2), each extend towards the inside of the window (A3), up to a guide face (61, 61 ') parallel to the clamping plane and cooperate, in the Z.High configuration, with two superimposed sliding faces, respectively (35) of a working chock (E3, E'3) and (150) of an intermediate chock (E2, E '2).

16. Rolling mill according to one of claims 11 to 15, characterized in that the support members (11, 12), (110, 120) chocks of the working rolls, respectively upper (C1), (C2) and lower (C'1), (C'2), are placed substantially at the rolling plane P1, between the projecting parts, respectively upper (6) and lower (6 ') of the two hydraulic blocks (B1, B2 ).

17. Rolling mill according to one of claims 11 to 15, wherein each chock (E1) is provided, on each side of the clamping plane (P2), at least one support member (11, 12) s' extending projecting from the corresponding sliding face (15) of the chock (E1), so as to cooperate with the camber cylinders (V1, V2), characterized in that, in each configuration, the members of '' support (11, 12), (11 ', 12') of chocks (E1, E'1) of the two working rolls (C1, C'1) are placed substantially at level (H1) of the rolling plane (P1), between the projecting parts (6, 6 ') of each block hydraulic (B1, B2), and that each support member (11) of a first working chock (E1) placed on a first side of the rolling plane (P1) is provided with at least one recess (13a) passage of the rod of at least one cambering cylinder (V1a) placed on said first side and crossing the rolling plane (P1) to bear, in the positive direction, on a corresponding support member (11 ') of the second working chock (E'1) placed on the second side of the rolling plane (P1), which is provided with at least one recess (13 ') for passage of the rod of at least one jack (V '1) bending placed on said second side and crossing the rolling plane (P1) to bear, in the positive direction, on the support member (11) of the first working chock (E1).

18. Rolling mill according to claim 17, characterized in that, on each side of the clamping plane (P2), each projecting part (6, 6 ') of a hydraulic block (B1), (B2) carries two groups single acting cylinders, respectively (V1, V'1), (V2, V'2) acting towards the rolling plane (P1) and (V3, V'3), (V4, V'4) acting on the side opposite to it, by resting on said projecting part (6, 6 '), and that the corresponding support members of the chocks (E1, E'1) are placed on three levels which remain substantially the same in all the configurations, respectively a central level (H1) for supporting the working chocks, corresponding substantially to the rolling plane, and two levels, respectively upper (H2) and lower (H'2), for supporting the intermediate chocks, placed respectively above and below the projecting parts (6, 6 ') of the hydraulic blocks (B1, B2).

19. Rolling mill according to one of the preceding claims, characterized in that the sets of bending cylinders, respectively upper (V) and lower (V) are centered substantially in two planes (Q1, Q2) parallel to the clamping plane ( P2) and spread symmetrically on either side of it.

20. Rolling mill according to one of claims 18 and 19, characterized in that, on each side of the clamping plane (P2) and on either side of the rolling plane (P1), each projecting part (6 ) a hydraulic block (B1) carries at least one central cylinder (V1) acting in the direction of the plane rolling (P1) and two lateral cylinders (V3a, V3b) acting in the direction opposite to the rolling plane (P1).

21. A rolling mill according to claim 20, characterized in that, in the quarto configuration, the lateral jacks (V3a, V3b) (V'3a, V'3b) act, in the positive direction, on the chocks (E1) ( E'1) working cylinders, respectively upper (C1) and lower C'1).

22. Rolling mill according to one of claims 7 to 21, characterized in that each chock (E1), (E2) of a large diameter cylinder (C1) or medium diameter (C2), consists of three adjoining parts , respectively a central part (1) for supporting a bearing for centering the cylinder (C1), (C2) corresponding and two end parts (2a, 2b) each carrying two support members (11a, 12a), (11b, 12b) extending on either side of the clamping plane (P2) and fixed on two lateral sides, perpendicular to the axis, of the central part (1), in a removable manner allowing, on the one hand, to secure the central part (1) with the two end parts (2a, 2b) for the transmission of the bending forces and, on the other hand, to turn the end parts (2a, 2b) relative to the central part (1), after separation of the three parts.

23. Rolling mill according to claim 22, characterized in that the central part (1) of each chock (E1) is provided, on each side of the clamping plane (P2), with a support member (11) ( 12) for at least a first central cambering cylinder (V1) placed on a first side of the rolling plane (P1), said support member (11) (12) comprising at least one recess (13) for the passage of the rod of at least a second central camber cylinder (V'1) placed on the other side of the rolling plane (P1).

24. A rolling mill according to claim 23, characterized in that each hydraulic bending block (B1) placed on one side of the clamping plane (P2) comprises a central group of jacks comprising at least two pairs of opposite jacks acting respectively on the support members (11, 11 ') of the central parts (1, l') of the two working chocks (E1, E'1) placed on either side of the rolling plane (P1), each pair comprising two opposite cylinders acting respectively in the positive direction (V'1, V1a) and in the negative direction (V1, V'1 a) on a support member (11, 11 ') of one of the chocks (E1, E '1), each cylinder (V'1) of positive bending of a first chock (E1) placed on a first side of the plane of rolling (P1) resting on a projecting part (6 ') of the hydraulic block placed on the second side of the rolling plane (P1) and passing through it passing through a recess (13') formed in the member d 'corresponding support (11') of a second chock (E'1) placed on the second side of said rolling plane (P1).

25. A rolling mill according to claim 24, characterized in that the central part (1) of a first working chock (E1) placed on a first side of the rolling plane (P1) comprises, on a first side of the plane of clamping (P2), a support member (11) comprising a single support part cooperating with a pair of opposite camber cylinders (V1, V'1) and framed by two recesses (13a, 13b) and, on the second side of the clamping plane (P2), a support member comprising two support parts (12a, 12b) spaced on either side of a single recess (14) and each cooperating with a pair of opposite jacks , the arrangement of the support members and jacks being reversed for the second working chock (E'1) placed on the other side of the rolling plane (P1).

26. Rolling mill according to one of claims 22 to 25, characterized in that the lateral jacks (V3a, V3b), bearing on each projecting part (6) of a hydraulic block (B1), (B2) act in the positive direction on support members (21a, 21b), (22a, 22b) formed respectively on the end portions (2a, 2b) of a chock (E1) of larger diameter constituting at least one intermediate chock in the sexto configuration or in the Z.High configuration.

27. A rolling mill according to claim 26, characterized in that the lateral jacks (V3a, V3b) act in the positive direction on support members (21a, 21b) formed respectively on the end portions (2a, 2b) d 'a larger diameter chock (E1) constituting a working chock in a quarto configuration.

28. Rolling mill according to one of claims 22 to 27, characterized in that the support members (21a, 21b), (22a, 22b) formed on the end portions (2a, 2b), respectively, of a chock (E1) of a cylinder (C1) of large diameter (E2) or of a cylinder (C2) of medium diameter, are provided with rollers (G) running on rails (R, 7) parallel to the plane rolling (P1) and clamping plane (P2) for the disassembly and reassembly of the corresponding cylinder by displacement parallel to its axis.

29. Rolling mill according to one of claims 22 to 28, characterized in that each chock (E3) of a small diameter cylinder (C3) used as a working cylinder in the Z.High configuration, consists of three parts adjoining, respectively a central part (3) for supporting a corresponding cylinder centering bearing (C3), provided, on each side of the clamping plane (P2), with a support member (31, 32) for at least two opposite camber cylinders, respectively positive (V'1) and negative (V1), and two end parts (4a, 4b) integral with the central part (3) and each provided on each side of the clamping plane ( P2), a support member (41a, 41b), (42a, 42b) carrying at least one roller (G) for rolling on a rail (R) parallel to the rolling plane (P1) and to the plane of clamping (P2), for removing the corresponding cylinder (C3) by moving parallel to its axis.

30. Rolling mill according to one of claims 28 and 29, characterized in that the cage (A) is equipped with dismantling rails (R) placed on three levels, respectively a central level (H1) corresponding substantially to that of the plane rolling (P1), comprising two superimposed rails (72, 72 ') for rolling the chocks of the working rolls, respectively upper and lower, and two levels, respectively upper (H2) and lower (H'2), each comprising a rail (71, 71 ') for rolling the chocks of the intermediate cylinders, respectively upper (C1) and lower (C'1).

31. Rolling mill according to one of claims 11 to 30, characterized in that at least one part (63, 64) of each projecting part, respectively upper (6) and lower (6 '), carrying a set of jacks bending, is slidably mounted, parallel to the rolling plane (P1) and to the clamping plane (P2), on the corresponding hydraulic block (B1, B2) and that the rolling mill comprises means for controlling the simultaneous axial sliding, with the bending jacks and a corresponding cylinder, moving parts (63, 64) of the projecting parts (6) placed respectively on either side of the clamping plane (P2) and on the same side of the rolling plane.

32. A rolling mill according to claim 31, characterized in that it comprises means for controlling the sliding of each pair of projecting parts (6) placed respectively on either side of the clamping plane (P2) and of the same side of the rolling plane (P1), with a large diameter intermediate cylinder (C1) in the sexto configuration and with a medium diameter intermediate cylinder (C2) in the Z.High configuration.

33. Rolling mill according to one of claims 31 and 32, characterized in that, on each side of the clamping plane (P2), each projecting piece, respectively upper (6) or lower (6 '), of a hydraulic block (B1, B2) has a central central part (62) relative to the cage (A) and two movable lateral parts (63, 64) placed on either side of the central part (62) and mounted slidingly axially on the hydraulic block (B1, B2), that each set of bending cylinders, respectively upper (V) or lower (V), comprises at least one central cylinder (V1) bearing on the fixed central part (62) of the protruding part and acting towards the rolling plane, and at least two lateral jacks (V3a, V3b) bearing respectively on the two movable lateral parts (63, 64) of the protruding part (6) and acting on the opposite side in the rolling plane (P1), and that each chock comprises a central part (1) provided, on each side tee, a support member (11) for at least one central jack (V1), and two end parts (2a, 2b) joined on either side of the central part (1) and each provided with each side of the clamping plane, a support member (21a, 22a), (21b, 22b) for a lateral jack (V3a, V3b) mounted on a corresponding movable part (63, 64) of the workpiece projection (6).

34. Rolling mill according to claim 33, characterized in that the support members (21a, 21 b) formed on each end part (2a) of a chock are offset in height relative to the axis (x'x ) of the cylinder so as to determine, by rotation of the end part (2a) around said axis, two levels of the support members with respect to the axis, respectively a level (H1) offset towards the rolling plane (P1) for a working cylinder chock in quarto configuration and a level (H2) offset from the side opposite to the rolling plane (P1) for an intermediate cylinder chock in sexto configuration.

35. Rolling mill according to one of the preceding claims, characterized in that one uses, in a sexto configuration, working rolls and intermediate rolls having, respectively, a means (C2) and a large (C3) diameter adapted to the height (h) of the windows (A3) of the two columns (A) of the cage and that shims of thickness (M, M ') are interposed between each end of the window (A3) and the corresponding chock (S1, S'1) of a support cylinder (S, S '), so as to reduce the height of the windows (A3) for the quarto and Z.High configurations.

36. Rolling mill according to one of the preceding claims, characterized in that the means (V, V) for applying the bending forces are arranged in hydraulic blocks (B1, B2) which, in all configurations, have a height not substantially exceeding the sum of the diameters of the two larger diameter cylinders (C1, C'1) used as working cylinders in the quarto configuration.