EP0908246B1 - Work rolls or intermediate rolls changing device of roll stands and stocking device - Google Patents

Abstract

Rolls in a rolling mill cage are changed using a guidance chassis and a device with a hook to pick up the intermediate rolls or the work rolls alone or the whole assembly by their ends. A device for changing rolls in a rolling mill cage comprises a guidance chassis (29) with an extraction device (28) to slide parallel to the axes of the rolls. A device (35) for picking up each of the work rolls (4) by its end and a moveable hook (37) for each of the two intermediate rolls (3), for the demounting and remounting either the two work rolls (4) alone or the assembly of work rolls (4). This also applies to the intermediate rolls (3) of which the dressings (6) roll on rails (8, 9) and are arranged respectively on the cage (1) on the guidance chassis. An Independent claim is also included for the method for changing rolls using this device.

Description

The invention relates to a device and a method for changing the rolls in a rolling stand and especially applies to a sexto type cage or "Z-High" in which intermediate cylinders are interposed between the working rolls and the support cylinders.

We know that a rolling mill understands, in a way general, a fixed cage having two uprights apart between which are arranged several cylinders superimposed on parallel axes, respectively two working cylinders defining an air gap of passage of the product and one or more cylinders of support, a clamping force being applied between the cylinders by mechanical or hydraulic cylinders.

To allow the application of the effort of tightening and adjusting the air gap, each cylinder is generally carried at its two ends by two bearings housed in support blocks called chocks, slidably mounted along faces of guide provided respectively on the two uprights of the cage and parallel to a passing clamping plane by the axes of the working cylinders.

In quarto rolling mills, each working cylinder is associated with a cylinder support.

In sexto-type rolling mills, a cylinder intermediate is interposed between each cylinder of work and a support cylinder.

By the way, when the diameter of the cylinders work needs to be particularly reduced it's advantageous to use so-called "multi-cylinder" rolling mills in which each working cylinder is associated with a set of support cylinders arranged on either side of the passing clamping plane by the axes of the working cylinders.

To ensure lateral support for each working cylinder without excessively increasing the number of support cylinders, it has also been proposed to just perfect the sexto type rolling mill in associating to each working cylinder two sets lateral support rollers arranged respectively, on either side of the working cylinder and each comprising a laterally extending roller along the working cylinder and supporting itself on at least two rollers.

In such a provision called, in English, "Z-High" and described, for example, in document US-A-4270377, each side support assembly is consisting of at least three associated rollers, mounted on a frame arranged in the space between the running plane of the laminated strip, the cylinder working and the intermediate cylinder and carried by arms articulated respectively on the two chocks of the intermediate cylinder.

It is necessary in a rolling mill to replace cylinders periodically, especially working cylinders, due to their wear or well to fit the rolling program.

Laminating should normally be stopped during these operations and we therefore seek to reduce, as much as possible this downtime.

In addition, in modern installations performing continuous rolling, disassembly and replacing cylinders often need to be maintained while engaged in the rolling mill, the metal strip which can therefore be damaged during replacement operations.

Likewise, the cylinder to be replaced and the cylinder new ones may be damaged by contact with other cylinders or the fixed parts of the cage. he it is therefore desirable that the cylinders are guided precisely with respect to the cage during their displacement.

To reduce replacement time and risk of damage to the cylinders, advantageous to perform these operations automatically or semi-automatic, by means of a replacement often including an organ extraction fitted with removable hooking means cylinders and mounted movable in translation along a direction parallel to the axes of the cylinders, the interior of a side receiving frame fitted with means for supporting and guiding the cylinders.

To ensure precise guidance, each cylinder is generally carried by its two chocks which have rollers rolling on fixed rails aligned respectively on the cage and on the receiving frame.

Furthermore, it is advantageous to use at minus two side frames mounted side by side on a auxiliary carriage movable perpendicular to axes of the cylinders so as to place one or the other of the two chassis in a replacement position for which the chassis rails are aligned with the fixed rails of the cage.

In this way new cylinders can be placed in advance on a carriage frame auxiliary, the other chassis remaining free for used cylinders. These are therefore first extracted of the cage to come on the auxiliary carriage and, by moving it, the new cylinders are brought into the axis of the cage and introduced into it.

A device of this kind, called in English "side-shifter" is described, for example, in the document EP-A-0.112.981.

In such an arrangement, the extraction or the introduction of the cylinders, relative to the cage rolling mill, is generally carried out by through the same extraction organ which remains permanently in line with the rolling mill stand. This extractor must therefore be released from the grip of the lateral carriage during the translation operation of this carriage parallel to the rolling direction to avoid interference. This contributes to increase the time required for a change of cylinders.

However, when the working cylinders have too small a diameter, it is difficult to combine chocks.

Each working cylinder is then provided, at its two axial ends, in the form of extensions cylindrical trunnions which rest on their ends on axial stops for holding in position of the cylinder during rolling.

To extract from the cage, or to introduce in it such a working cylinder devoid of chicks, it is no longer possible to do so slide on rails.

Generally, we use a gripping device under load consisting of a suspended operating rod an overhead crane and fitted at one end with a cylindrical recess called "cannon". By means of the bridge rolling, the rod is placed in alignment with the cylinder to be replaced and the "barrel" is engaged on the trunnion. The rod is associated with a counterweight to balance the weight of the cylinder which can thus be lifted and removed from the cage.

Due to the use of an overhead crane, a such device is imprecise and therefore it is necessary, to avoid any risk of deterioration, the cylinder to be replaced is relatively insulated other cylinders and fixed parts of the cage.

It has already been proposed, in document US-A-3,866,455, to show a caregiver to "canon" on a type replacement device "Side-shifter."

In this known arrangement, the device extraction is mounted, as usual on a carriage movable on fixed rails, in parallel to the axes of the cylinders, and cooperating with two auxiliary trolleys movable transversely. The extraction device is provided with two vertically movable cannon support which can be adjusted at each cylinder work to slip on the trunnion of it, the working cylinder can then be lifted in cantilevered.

Such a provision, in which each working cylinder is held in overhang by a variable level support member does not allow ensure precise positioning of the cylinder and is therefore hardly applicable to rolling mills of the Z-High type mentioned above, in which each working cylinder is held tight between two lateral support roller groups.

Usually in rolling mills of this type, each working cylinder forms, with the cylinder associated intermediary and the two sets of lateral support rollers, an "insert" which can be disassembled as a whole, the assembly being supported by two intermediate cylinder chocks which can be fitted with rollers rolling on rails guide.

Cylinder replacement operations are therefore quite complicated and require bulky devices since it must be dismantled the entire insert even if it has to be replaced only the working cylinder. Furthermore, after disassembly of the insert, replacement of the cylinder work is quite difficult to do quickly and automatically without interference from others parts of the insert.

Now we are brought into the facilities modern, to replace the cylinders quite often work, for example for a change of program and this operation must therefore also be carried out as quickly as possible. In addition, in most recent installations working in continuous rolling it is interesting to have the possibility of keeping the laminated strip engaged in the cage during replacement operations.

The object of the invention is to solve the whole of these problems through a change device of cylinders which allows to perform quickly and simply all the replacement operations for working cylinders, when these are devoid chocks at their ends, reducing or eliminating the risk of interference between different mechanical organs called to move. Such a device can operate very reliable while remaining relatively constructed economic.

The invention is specially adapted to a Z-High type rolling mill because it allows, on the one hand remove the two working rolls, alone, either the whole insert with the cylinders intermediaries and associated support packages and, on the other hand to remove from this assembly the cylinder of work without any risk of interference with the intermediate cylinder or support rollers. Of more, the invention also makes it possible, if necessary, to remove a single working cylinder or a single intermediate cylinder.

• deux cylindres de travail à axes parallèles, respectivement supérieur et inférieur définissant un entrefer de passage de la bande, chaque cylindre de travail étant prolongé, à au moins une extrémité par un tourillon,
• deux ensembles de soutien, respectivement, de chaque cylindre de travail, comportant chacun au moins un cylindre intermédiaire,
• des moyens de réglage des niveaux relatifs des axes de chacun des cylindres par rapport à la cage déterminant quatre niveaux de démontage, respectivement des deux cylindres de travail et des cylindres intermédiaires pour lesquels chaque cylindre de travail est écarté du cylindre intermédiaire correspondant,
• deux paires de rails parallèles aux axes des cylindres, ménagés sur la cage à deux niveaux constants sur lesquels viennent reposer, respectivement, chacun à son niveau de démontage, les deux cylindres intermédiaires, respectivement supérieur et inférieur chacun par l'intermédiaire d'organes d'appui coulissant pour le démontage du cylindre intermédiaire correspondant,

The invention therefore applies, in general, to a rolling mill comprising, inside a fixed cage and on either side of a running plane of a strip to be laminated:

• two working cylinders with parallel axes, respectively upper and lower defining a gap for passage of the strip, each working cylinder being extended, at at least one end by a pin,
• two support assemblies, respectively, for each working cylinder, each comprising at least one intermediate cylinder,
• means for adjusting the relative levels of the axes of each of the cylinders with respect to the cage determining four levels of disassembly, respectively of the two working cylinders and of the intermediate cylinders for which each working cylinder is spaced from the corresponding intermediate cylinder,
• two pairs of rails parallel to the axes of the cylinders, formed on the cage at two constant levels on which come to rest, respectively, each at its disassembly level, the two intermediate cylinders, respectively upper and lower each by means of organs d 'sliding support for dismantling the corresponding intermediate cylinder,

• un dispositif de manutention placé sur un côté de la cage et comprenant au moins un châssis de guidage manutention sur lequel sont ménagées deux paires de rails alignées respectivement avec les deux paires de rails de la cage,
• au moins un dispositif d'extraction monté coulissant à un niveau constant sur le châssis de guidage, parallèlement aux axes des cylindres, et déplaçable entre une position rapprochée de la cage, pour le démontage et le remontage des cylindres, et une position écartée de retrait des cylindres à l'intérieur du châssis,
• des moyens de prise en charge de chacun des cylindres de travail comprenant un organe de support monté sur le dispositif d'extraction et muni de deux logements centrés respectivement sur deux axes écartés d'une distance constante égale à l'écartement des niveaux de démontage des deux cylindres de travail, le niveau de l'organe de support étant réglé de façon que, dans la position rapprochée du dispositif d'extraction, chaque logement soit centré sur l'axe de chaque cylindre de travail à son niveau de démontage et s'engage de façon amovible, sur le tourillon du cylindre de travail correspondant, par déplacement axial du dispositif d'extraction, les moyens de réglage du niveau de chaque cylindre de travail pour la prise en charge, en porte-à-faux, dudit cylindre de travail par l'organe de support déterminant, après engagement du tourillon un déplacement vertical relatif de ce dernier par rapport au logement correspondant,
• des moyens amovibles d'accrochage de chacun des deux cylindres intermédiaires, ménagés sur le dispositif d'extraction et actionnés sélectivement pour la commande du démontage et du remontage de chaque cylindre intermédiaire, par déplacement axial, dans le sens correspondant, du dispositif d'extraction, en coulissant sur les rails alignés.

According to the invention, the cylinder changing device comprises:

• a handling device placed on one side of the cage and comprising at least one handling guide frame on which two pairs of rails are arranged respectively aligned with the two pairs of rails of the cage,
• at least one extraction device mounted sliding at a constant level on the guide frame, parallel to the axes of the cylinders, and movable between a position close to the cage, for disassembly and reassembly of the cylinders, and a discarded position of withdrawal cylinders inside the chassis,
• means for taking charge of each of the working cylinders comprising a support member mounted on the extraction device and provided with two housings centered respectively on two axes spaced apart by a constant distance equal to the spacing of the dismantling levels of the two working cylinders, the level of the support member being adjusted so that, in the close position of the extraction device, each housing is centered on the axis of each working cylinder at its disassembly level and s' removably engages, on the trunnion of the corresponding working cylinder, by axial displacement of the extraction device, the means for adjusting the level of each working cylinder for taking over, in cantilever, of said work by the determining support member, after engagement of the journal a relative vertical displacement of the latter relative to the corresponding housing,
• removable means for hooking each of the two intermediate cylinders, arranged on the extraction device and selectively actuated for controlling the disassembly and reassembly of each intermediate cylinder, by axial displacement, in the corresponding direction, of the extraction device , sliding on the aligned rails.

Particularly advantageously, the organ support includes a single piece in which are formed two cylindrical bores constituting each accommodation in which a party commits end of the journal, each bore being extended, its lower part on the side of the cylinder, by a projecting part in the form of a semi-cylindrical cradle, and on which comes to rest, in supported position, the remaining part of the trunnion.

In the case of a Z-High rolling mill where each working cylinder is placed in an insert comprising two lateral support assemblies carried by the chocks of an intermediate cylinder, the extraction device can determine, selectively, through the means removable attachment, disassembly and reassembly, either working cylinders alone or the whole of each insert, each cylinder of work being carried by the support member and kept away, at a determined level, from the cylinder intermediate and lateral support assembly corresponding sliding on the guide rails of the intermediate cylinder.

Generally, the cage is provided with means removable support, at least, from the working cylinder upper, having two positions, respectively one support position of said cylinder at its level of disassembly and a cleared position. In this case taking over of said working cylinder by the organ of support is effected by erasing said means support after commitment of the corresponding accommodation on the journal of the working cylinder.

Furthermore, after opening the cage, the lower working cylinder rests on the cylinder lower middle which is associated with means adjusting its level in relation to the cage. In in this case, said level adjustment means are first adjusted to place the cylinder work below its dismantling level for the engagement of the lower housing of the organ of support on the trunnion of said working cylinder lower and to be determined by lowering the cylinder lower intermediate, taking charge of lower working cylinder by the support member.

In a preferred embodiment, uses a side-shifter device comprising at least two guide frames mounted side by side side by side on a carriage that can be moved perpendicularly to the axes of the cylinders. In this case, however, at instead of using, as usual, only one extraction device, both guide frames are each associated with an extraction device and can be rotated in position replacement, one of the chassis being fully initially empty for receiving cylinders used and the other chassis being loaded with at least one pair of working cylinders carried by the device corresponding extraction to ensure almost immediate replacement of said cylinders.

In addition, the auxiliary carriage carrying the two guide frames each associated with a extraction device can advantageously be mounted on a main handling trolley movable, parallel to the axes of the cylinders, between a replacement position in contact with the rolling stand and a separate maintenance position and comprising, at its end facing the cage rolling mill, a connecting part comprising two side uprights on which are mounted rail sections arranged in line with the rails of the cage and on which the rails of each guide frame, by displacement transverse of the auxiliary carriage.

According to another particularly characteristic advantageous, the device is associated with a rack mechanized storage associated with the change of cylinders, and from which can be carried out, automatically, the loading or unloading of new working cylinders or refurbished, and worn out working cylinders.

Advantageously, the storage rack includes at least one box spring on which are arranged at least two storage locations for cylinders of work each provided with a pair of spread cradles, centered on an axis parallel to the axes of the cylinders of the rolling mill, for depositing, on said bed base, a working cylinder provided at both ends with two journals resting on said separated cradles, one of said places being free for deposit of a used working cylinder and the other of said locations being occupied by a cylinder of replacement.

The invention also covers other advantageous characteristics which are the subject of subclaims and will be described in more detail with reference to an illustrated embodiment by the attached drawings, which are in no way limiting.

La Figure 1 est une vue schématique en coupe verticale suivant la ligne I-I de la Figure 2 d'une cage de laminoir de type sexto avec appuis latéraux et du dispositif de changement de cylindres selon l'invention.

La Figure 2 est une section suivant la ligne II-II de la Figure 1 avec un dispositif de changement de cylindres comportant deux extracteurs montés sur un chariot latéral.

La Figure 3 est une vue semblable à la Figure 2 d'une variante de réalisation dans laquelle trois dispositifs extracteurs sont montés sur un chariot latéral.

La Figure 4 est une coupe verticale, orthogonale aux axes des cylindres , à plus grande échelle, d'une cage de laminoir de type sexto avec appuis latéraux.

La Figure 5 est une vue de dessus d'un dispositif avec chariot latéral équipé de deux dispositifs extracteurs.

La Figure 6 est une vue en élévation d'un râtelier mécanisé pour cylindres de travail.

La Figure 7 représente schématiquement, en coupe transversale, l'ensemble d'un atelier de laminage équipé d'un dispositif de changement de cylindres selon l'invention.

Furthermore, the invention relates to a method for changing cylinders as defined by claim 17.

Figure 1 is a schematic view in vertical section along line II of Figure 2 of a rolling mill stand of the sexto type with lateral supports and of the cylinder changing device according to the invention.

Figure 2 is a section along line II-II of Figure 1 with a cylinder changing device comprising two extractors mounted on a side carriage.

Figure 3 is a view similar to Figure 2 of an alternative embodiment in which three extractor devices are mounted on a side carriage.

Figure 4 is a vertical section, orthogonal to the axes of the cylinders, on a larger scale, of a rolling mill stand of the sexto type with lateral supports.

Figure 5 is a top view of a device with side carriage equipped with two extractor devices.

Figure 6 is an elevational view of a mechanized rack for working rolls.

Figure 7 shows schematically, in cross section, the whole of a rolling workshop equipped with a cylinder changing device according to the invention.

Figures 1 to 4 schematically show a sexto or Z-High rolling mill stand 1 comprising two sets of cylinders E1, E2, respectively upper and lower, symmetrical with respect to average rolling plan P or pass line. Each set includes a support cylinder 2, a intermediate cylinder 3 and a working cylinder 4 decreasing diameters, these cylinders having their axes parallel and placed substantially in a plane of clamping P 'perpendicular to the rolling plane P.

Support cylinders 2 and cylinders intermediaries 3 are rotatably mounted around their axis and are guided vertically in the uprights 1a, 1b of cage 1, so as to be able to move vertically under the action of clamping means 17 (Fig.4) described below. In the position shown in Figure 1, the cage is in position open, the cylinders being slightly apart each other to allow mounting and disassembly. In working configuration, the cylinders support 2, 2 'are in contact with the cylinders intermediaries 3, 3 'which are themselves in contact with the working cylinders 4, 4 'between which is tightening the laminating strip 5 under the action of screws or cylinders 17.

Furthermore, non-driving means represented, placed on a "training" side of the cage 1, that is to say on the left in FIG. 1, allow to rotate the cylinders intermediaries 3 who train themselves working cylinders 4 to determine the progress of the strip 5 clamped between said cylinders.

On the "operator" side, to the right of cage 1, according to Figure 1, is placed a device C of changing working cylinders 4 and cylinders intermediaries 3.

Support cylinders 2, 2 'and cylinders intermediaries 3, 3 ′ are fitted, at each end, a chock made up, in the usual way, of a housing in which a centering bearing is mounted a pin at the axial end corresponding cylinder.

Conventionally, each chock is threaded in a window provided on the corresponding amount 1a, 1b of cage 1 and can slide vertically along guide faces provided on the sides of the window or, for chocks 6 cylinders intermediates 3, 3 ', on solid pieces fixed on the cage and forming hydraulic blocks B carrying hydraulic cylinders 61, 61 '(symbolized in the figure by arrows), which allow to spread or bring together the chocks to determine a bend, respectively positive or negative of the intermediate cylinders and, by Therefore, working cylinders.

In the example shown in Figure 1, the two uprights of the cage 1 are provided with means of tightening such as screws 17a resting on the chocks 2a of the upper support cylinder 2 which themselves rest on balancing cylinders 2b mounted on hydraulic blocks B. On the other side tape, chocks from the support cylinder lower 2 'rest on hydraulic cylinders 17b forming adjustable shims.

In this way, during a rolling pass, the clamping screws 17a determine the general level of the pass line while the hydraulic cylinders 17b allow adjustment of the clamping force and the width of the air gap between the working rolls 4.

To allow disassembly of the cylinders intermediates 3, 3 ', their chocks 6, 6' are provided externally of rollers 7, 7 'which, by vertical displacement of the cylinder, come to rest on rails 8, 8 'provided on the hydraulic blocks of the cage 1, and extended by rails 9, 9 'formed on the handling device C. Each chock 6, 6 'located on the operator side is equipped with a body attachment 10 allowing handling.

Adjusting the level of the cylinders intermediates can be carried out by the cylinders of bending 61. However, the level of the cylinder lower intermediate 3 'which rests on the cylinder 2 'support, can also be determined by the shims lower 17b when these are adjustable.

In a known manner, to allow movement vertical of the cylinders, the parts 8a of the rails 8, 8 'corresponding to the two uprights of cage 1 can be retracted so as not to exceed in protrusion on the guide faces, during rolling. These retractable parts are put back in place only after opening the cylinders for allow the withdrawal of these.

If necessary, the cage 1 can also be provided rails not shown allowing disassembly of support cylinders, respectively upper 2 and lower 2 '.

As noted, the working cylinders 4, 4 'which have a reduced diameter, do not have chocks and are provided, at each axial end, with cylindrical trunnion extensions 11 which are supported, in the disassembly position, on removable support means 62, 62 'indicated schematically in Figure 1.

The invention applies especially to a Z-High type rolling mill in which each cylinder intermediary 3 is associated, as shown on the Figure 4, with two sets 13 of lateral support placed on each side of working cylinder 4 and extending over its entire length.

Each lateral support assembly 13 comprises at minus three rollers of axes parallel to those of cylinders, respectively a roller 15 extending the along the working cylinder and supporting itself on two other rollers. The set of rollers is mounted on a side member 14 carried at its two ends, by arms articulated respectively on the two chocks 6 of the intermediate cylinder 3. These are sliding mounted, in known manner, between faces vertical guide provided on the two blocks hydraulic B fixed on the uprights of the cage 1 and carrying the hydraulic camber cylinders 61, 61 '. These are supported on lateral ears (not represented) of choise 6 and can also provide the height adjustment of the intermediate cylinders, especially for opening the cage.

In the preferred embodiment shown, by way of example, in FIG. 4, the two lateral support assemblies 13 of each cylinder 4, 4 'are associated respectively with two horizontal beams 16 placed symmetrically on the side and other of the clamping plane P 'and movable horizontally to adjust their position lateral to the working cylinder. Each beam 16 extends between the two uprights la, 1b, the along the side roller support side member 14 corresponding and therefore defines, for the support assembly lateral 13, a reference face whose position can be adjusted by horizontal sliding of the beam 16, for example under the action of screw-nut adjustment 16a mounted on stand 1 and each controlled by an autonomous motor. We avoid, however, to exert a horizontal clamping force of the working cylinder 4 between the two sets support 13 so as not to hinder movement vertical of the intermediate cylinder 3 with its chocks 6, for example under the action of the jacks bending. A slight clearance is therefore left between the beams 14 and the corresponding faces of the beams 16 which can slide one over the other ensuring simply lateral support of the working cylinder 4, in particular to enable it to resist horizontal bending forces when passing the product.

The lateral support sets 13, 13 'of each working cylinder 4, 4 'are supported by chocks 6, 6 'of the corresponding intermediate cylinder 3, 3 '. In addition, each 4, 4 'working cylinder can rest, via its pins 11 on removable supports 62, 62 ', which have not been shown schematically in Figure 1 and which consist of mounted eclipsable forks, for example, on hydraulic blocks and coming place under the pins 11 of the working cylinder to support it, said forks being able to be laterally cleared to release the cylinder from work when it comes into contact with the product.

When a replacement is required, the rolling is stopped but it is possible so advantageous, to leave the band engaged between the working cylinders which are simply spread apart, towards up and down, at a sufficient distance from the band to allow handling.

To this end, by means of hydraulic cylinders 17b, lower the lower support cylinder 2 whose chocks come to rest, in the low position, on stops or else, by means of rollers, on rails not shown, allowing removal of the lower cylinder 2.

Similarly, the balancing cylinders 2b, which lean on hydraulic blocks B, lift the upper support cylinder 2 in the high position, the screws 17a being raised.

The two inserts, respectively lower and upper, are then held by the camber cylinders 61, 61 '.

The working rolls 4, 4 'then rest on the forks 62, 62 ', and the level thereof is determined so as to leave, between each working cylinder 4, 4 'and the intermediate cylinder corresponding 3, 3 ', a light play allowing axial displacements without risk of contact between the cylinders.

After opening the cylinders, we set up the retractable parts 8a of the running rails 8 and we lower the two inserts by means of the jacks bending 61, 61 'the chocks 6, 6' of the cylinders intermediaries 3, 3 'coming to rest, by their rollers 7, 7 ', on the rail sections 8a which are placed in the extension of the fixed rails 8, 8 'whose level is set to leave an interval between the generators opposite each cylinder intermediate 3, 3 'and support cylinder corresponding 2, 2 '. Since, as we have indicated, each working cylinder 4, 4 'is maintained slightly away from the intermediate cylinder 3, 3 'by the support forks carried by the chocks of the intermediate cylinder, all cylinders are away from each other and can be moved freely.

The cylinder changing device C includes a mobile main cart 18 in translation in a direction parallel to axes of cylinders 3 and 4, relative to cage 1. The carriage 18 rolls, by wheels 19, on rails R (Fig. 2) fixed to the ground. For example, as shown schematically in Figure 7, the carriage 18 is provided to move from the work area to proximity of rolling stand 1 to a maintenance position away from cage 1 and placed in a hall 20 for rectification or renovation working and intermediate cylinders, located on the side of main building 21 where the rolling mill 1.

The median plane of the industrial truck 18 is centered on the clamping plane P 'of the cage rolling mill.

To reduce handling and speed up operations, in the preferred embodiment shown in Figure 1, the main carriage 18 is associated with a side carriage 25 movable in translation on the carriage 18 in a direction parallel to the direction of advance in the rolling mill 1, that is to say perpendicular to the axes of the cylinders. For example, the carriage 25 can be carried by wheels 26 (Fig. 2) rolling on rails 27 fixed on the main carriage 18 and parallel to the steering in advance in the rolling mill.

On the side carriage 25 can be placed at at least two chassis 29 each equipped with a device 28 cylinder extractor, displaceable in translation on the chassis 29, in a direction parallel to the axes of cylinders 3 and 4. The two devices extractors 28 therefore move with the carriage lateral 25, perpendicular to the axes of the cylinders, to be placed, in turn, in the alignment of the cage.

Figures 2 and 3 3 show respectively, in cross section, two and three installations extractor devices.

Each chassis 29 associated with a device extractor 28 is limited by two load-bearing walls which are provided at their upper level and in the lower part, two pairs of rails 9, 9 'coming respectively in the extension of the pairs of fixed rails 8 and 8 'when the extractor device 28 concerned has its vertical mediator plan confused with the clamping plane P 'of the cage 1.

To ensure continuity between cage 1 and each chassis 29, the carriage is provided, at its end facing cage 1, of a part of link 22. This presents, in section transverse, a U-shape with two uprights side 22 apart which, in the close position of the carriage 18, surround the attachment members 10 chocks 6. On the two uprights 22 are fixed sections of rails 23, 23 ′ placed at the level of the rails 8, 8 'of cage 1 and rails 9, 9' of the carriage 25 and separated by the same distance.

Thus, when the handling carriage 18 is found in its position close to the cage 1, each chassis 29 can come to center, by movement of the carriage 25, on the median plane P 'of the cage, the two pairs of rails 9, 9 'being connected to the two pairs of fixed rails 8, 8 ′ by the sections 23, 23 'to form two continuous raceways. Each chassis 29 thus forms a reception box or cylinder storage.

Advantageously, the vertical walls 29 limiting each receiving box may include, to their ends facing cage 1, each one projection 30 in the shape of a trapezoidal nose, formed substantially halfway up, so as to engage in a notch 31 of corresponding shape provided in the corresponding side wall of the end 22 of the carriage 18.

Each extractor device 28 is guided on the auxiliary carriage 25, via two guide rails 32, which are fixed substantially at mid-height load-bearing walls 29 and can be extended on the projecting part 30, beyond the rails 9, 9 'so as to penetrate, at the level of the rails 23, 23 ', between the attachment members 10, 10' of the intermediate cylinders 3, 3 ', in position close to the industrial truck 18.

The displacement on the rails 32 of the device extractor 28 is controlled by a rack and pinion system driven by an electric gear motor 33 mounted on the extractor device 28 and which controls the rotation of a pinion 33a meshing on a rack 33b fixed on the carriage 25, along the rails 32 (Fig. 5).

Since the working cylinders are free of chocks and provided simply, at their ends, protruding pins, the device extractor is provided with a support member 34 arranged so that each work cylinder can be gripped by the pin on the operator side, holding the working cylinder cantilevered in a housing 35 of the support member. In addition, to perform simultaneously replacing the two cylinders of work, keeping them apart from each other, each at a determined level, the support member 34 is fixed at a constant level on the device extractor 28 and consists of a massive piece comprising two housings in the form of blind bores 35 of parallel axes, spaced vertically one distance equal to that separating the geometric axes cylinders 4, 4 'when these rest, in replacement position, on the forks of support 62, 62 '. The diameter of blind holes 35 is substantially equal to the diameter of the pins 11, with a simple game allowing to easily engage the pins 11 in the bores 35 by a movement of translation of extractor 28 in the direction geometric axes of the cylinders 4, 4 '.

Thanks to this arrangement all trips of the extraction device 28 are carried out in taking as guide reference the rails 9 of the chassis 29 aligned with the rails 8 of the cage 1. It this results in excellent accuracy and great speed of cylinder replacement operations of work.

Generally speaking, the levels relative of the cylinders are variable since they depend on their wear. However, in the arrangement according to the invention, the management of working cylinder is always done at one level well determined with reference levels fixed guide rails 8, 8 ', the two housings 35 being placed on a single mounted piece sliding at a constant level defined by the rails 32 of chassis 29.

In practice, for each rolling stand, and whatever the wear of the cylinders, the levels of replacement of intermediate cylinders are defined by rails 8, 8 'and the replacement levels of working cylinders are determined by the positions support members 62, 62 ', the axes of the cylinders being removed in this position from a constant distance. So just plan, if if necessary, a height adjustment of the solid part 34 relative to the extraction carriage 28 to align, with precision the axes of the housings 35 on the axes working cylinders. This setting can be done in advance on all devices extraction 28 associated with the cage 1, so that, after installation of an extraction device in the median plane of the cage, the housings 35 engage directly in the pins 11 of the cylinders of work 4, 4 'placed in the disassembly position.

It is best, however, to limit the depth of engagement of each housing 35 for avoid all risks of misalignment.

This is why, in the provision preferential shown in the figures, the depth of each bore 35 is less than the length of pin 11 of which only the extreme part commits to the accommodation thus constituted and it is extended, at its lower part, by a part substantially cylindrical forming a cradle 36 and extending in the direction of the cylinders 4, 4 '.

The engagement of the ends of the pins 11 in the housings 35, 35 'is therefore done on a distance small enough to avoid friction and the risk of misalignment. At this time, it is enough to erase the forks 62, 62 'for supporting the working cylinders 4, 4 'so that these come to rest on the lower parts in projection forming cradle 36 and are held in overhang by the pins 11 which are supported on the support member 34 in two spaced zones, one of the other, respectively upwards on the outer side and down on the inner side.

The relative reduction thus achieved is simply equal to the clearance left between the housings 35 and the pins 11 to allow threading easy of these. The threading length, equal to the depth of the housing 35, must be simply sufficient to allow overhang of the cylinder without risk of matting of the parts support.

We could also plan other arrangements for taking charge of cylinders by a double and level support member constant.

For example, the support member 34 could have, for each working cylinder, a clamping member comprising two pairs of jaws, respectively lower and upper, maintained open to thread on pin 11 of each working cylinder 4, 4 'by axial displacement of the extraction device 28, each pair of jaws being centered on an axis placed in alignment with the axis of the working cylinder, at the disassembly level of it.

After threading the pin, the two jaws are clamped on it and the cylinder 4 is thus cantilevered by its journal end 11.

In all cases, the very precise guidance of the extraction device 28 on its rails 32 allows the removal of the two working cylinders 4, 4 'without risk of damage, each cylinder being worn by a constant level support and moving in translation parallel to its axis.

Furthermore, each extractor device 28 is equipped so that it can be removed, according to requirements, i.e. the two working cylinders 4, 4 ', either the two inserts each comprising a cylinder intermediate with the associated working cylinder and its two lateral support assemblies.

Indeed, as indicated above, the lateral carriage 25 on which the device is mounted extraction 28 is arranged so that the latter can enter the space between chocks 6, 6 'of the intermediate cylinders 3, 3', in a position for which the rails 8, 8 'of the cage 1 are aligned with the rails 23, 23 'of the carriage handling 18 and the rails 9, 9 'of the carriage lateral 29.

The extraction device 28 which moves on the rails 32 is provided with removable gripping members who, if necessary, can commit to the attachment means 10, 10 'of the chocks 6, 6' of the intermediate cylinders 3, 3 'to remove the assembly of each insert with the working cylinder corresponding.

For example, in the embodiment preferential shown in Figure 1, the extractor device 28 is provided, in the upper part and in the lower part of vertical attachment fingers 37, directed in opposite directions. These fingers 37 are movable vertically and are controlled, for example, by a electric or hydraulic cylinder 38, of horizontal axis, connected to fingers 37 by a system of links for control their vertical movement. To this end, we could also use a system controlled by cam.

When the extractor device 28 is in loading position, corresponding to the engagement journals 11 in the bores 35, the exit of fingers 37 which engage in orifices correspondents arranged on the hooking members 10 intermediate cylinders 3.

As indicated above, the chocks 6, 6 ' of each intermediate cylinder carry the sets lateral supports associated with the working cylinders corresponding. By hanging the organs 10 by the fingers 37, so we can remove the entire insert which is driven by the extractor 28 in translation to the right as shown in Figure 1.

The working cylinder 4 is carried by the member support 34 while the intermediate cylinder 3 as well as the lateral support assemblies are worn by the chocks 6, which via the rollers 7, roll successively on the rails 8, 23, 9 until the entire insert is placed on the side carriage 25.

However, since the housings 35 are maintained, by sliding of the support member 34, at a constant level relative to the rail levels 8, 8 ', 9, 9', the translation operations can be done safely, without risk interference between the cylinders.

It is thus possible to remove the cylinders of the cage and transport them, by means of the trolley handling 18, to the maintenance area where they are replaced by new cylinders. These are then introduced into the cage by displacement in reverse direction of the industrial truck 18 and extraction device 28. All movements are perfectly guided from the reference level defined by rails 8, 9, 8 ', 9'.

As noted, replacement can be almost immediate if the handling trolley 18 is provided with a lateral carriage 25 carrying at least two reception boxes 29 each provided with a device extraction.

For this purpose, as shown in Figure 5, one boxes 29a is empty and can be placed in advance in line with the cage. After withdrawal of worn cylinders in the empty box 29a, the carriage 25 is move laterally to center in the midplane P 'of the cage, the neighboring box 29b in which have replacement cylinders have been placed in advance which can thus be introduced immediately into cage 1.

It should be noted that the device according to the invention also has the advantage of allowing selective replacement, i.e. working cylinders alone, or of the whole of each insert, respectively higher or lower.

When the lateral carriage 25 has two reception boxes 29 each associated with a extractor device 28, as illustrated in the figure 2, the first box 29a is completely empty for allow exit, as required, either working cylinders 4, 4 'alone, i.e. all of each insert comprising an intermediate cylinder 3, the lateral support assemblies and the cylinder job. We can even, exceptionally, withdraw a single working cylinder. Indeed, after the engagement housings 35, 35 'on the pins of the two working cylinders 4, 4 ', you cannot order the retraction of the support forks only for a only one of the two working cylinders, for example the upper cylinder 4 which, in this case, comes alone rest on the cradle 36 associated with the housing 35. The other cylinder, for example, the lower cylinder 4 'is still supported by its forks support 62 'and therefore remains inside the cage 1 when the extraction device 28 is moved aside.

Likewise, fingers 37 can be controlled selectively so as to determine the withdrawal, with the extraction device 28, from one or other of the intermediate cylinders associated with support assemblies side.

Thus, in the reception box 29a, initially empty, of carriage 25, only, the cylinders to be replaced.

If a single cylinder of work, the industrial truck 18 then brings the extraction device in maintenance position for replacing the cylinder.

However, this case is quite rare, and in general, we proceed to the replacement of the two cylinders of work at the same time.

This is why, if the device of the side-schifter type shown in the figures, the second box 29b of the carriage 25 is equipped in advance of two complete inserts, respectively upper and lower, each comprising a working cylinder, an intermediate cylinder and its support assemblies side. However, since each box of reception is equipped with an extraction device, working cylinders and cylinders intermediates are worn separately, respectively by the support member 34 and by the rails 9, 9 'of the chassis 29b.

By transverse movement of the carriage auxiliary 25, then center the second box of reception 29b in the median plane P 'of the cage. When only the working rolls 4, 4 ', the hooking fingers 37 are erased so that the cylinders intermediate and lateral support assemblies remain in place in the frame 29b, the device extraction 28 introducing only into the cage, the two working cylinders 4, 4 '. The forks 62, 62 'are then put in place by lifting slightly the working cylinders which discharge thus the support members 34 and the device 28 can be removed.

However, if the inserts have been removed complete, just flip your fingers hook 37 or just one of them to introduce in the cage, either the two inserts, or only one insert to replace the one that was removed.

In a more sophisticated layout illustrated in FIG. 3, the lateral carriage 25 is provided with three extractor devices 28; in that case two extractor devices are loaded with cylinders new, the other being empty to release a first game worn cylinders in the cage. It is then possible make two consecutive cylinder changes without having to bring back the whole of the main carriage and side carriage 25 in the workshop of rectification 20.

After the first change, we leave in the alignment of the cage, the space thus freed from the carriage 25 which can be used for removing cylinders. A simple movement of the carriage 25 then makes it possible to center the third box in front of cage 1 to make a second change.

It is thus possible to change very quickly rolling program leaving the strip engaged.

Of course, the device is not shown on figures only schematically but it involves all the auxiliary organs necessary for operation of the carriages 18, 25 and of the device extraction 28, in particular for winding and the unwinding of the electric cables and / or hydraulic lines connected to the different moving parts.

On the other hand, the movements of the carriages can be ordered in various ways. Through example, to ensure displacement in translation extractor carriages 28, the gear motor group 33 which moves along a rack 33b could be replaced by a push chain powered by a motor mounted directly on the carriage 25.

As shown in Figure 7, the loading / unloading of new / used cylinders on the extractor devices 28 of the side carriage is performed in a rectification workshop 20 located at side of hall 21 of the rolling mill.

Since even if the complete inserts, the working cylinders 4, 4 'are held cantilevered by the support member 34, it is particularly advantageous to use, for the replacement, one or more storage racks mechanized 40 can be placed in front of the carriage handling 18 when it is in its most remote position inside the workshop rectification 20.

Figure 6 is a cross-sectional view of such a device which is mounted on a frame lower 42 carried by wheels 43 rolling on rails 44 parallel to the direction of advance of the strip to be laminated, i.e. perpendicular to axes of the cylinders in place in the cage 1.

In the example shown in Figure 6, the device comprises two racks 40, 40 'arranged side by side on a frame 47 resting on the frame 42 by means of four supports 51 in height adjustable, which may consist, for example, of screw-actuators actuated synchronously by through link bars 52 and cross references angle 53, by a geared motor group 56 allowing a vertical up and down movement of the frame 47 carrying the racks 40, 40 '.

Each rack consists of a chassis 46 in U shape supporting two superimposed bed bases, respectively upper 48 and lower 49, equipped each of a series of 50 parallel cradles and defining two levels of reception.

The upper level 48 cradles are at right those of the lower level 49 and the distance vertical between the two reception levels is equal to the vertical distance between the axes of blind bores 35 of the support member 34.

In the example considered, each level comprises five cradles 50 each rack 40 can therefore receive five pairs of working cylinders 4.

The box springs 46 are open on the right side on figure so that by a movement of longitudinal translation to the left of the device extraction 28, the two working cylinders 4, 4 ' carried by the support member 34 can be placed above two superimposed cradles 50 which have been left free on the two box springs 48 and 49.

By means of the support members 51 it is then possible raise frame 47 so that the two box springs 48, 49 take over the two cylinders of work 4, 4 'which come off slightly from protruding parts 36 of the support member 34 and are thus deposited on the two free locations of the rack 40.

The support member 34 being discharged, it is possible to move back the extraction device 28 to release the journals of the worn cylinders then center a transverse movement of the rack 40 to control, depending on the program to be carried out, a pair of new cylinders on the mediator plane of the device extraction. This is then advanced so that the housings 35 of the support member 34 engage on the pins of the two replacement cylinders.

After engagement, the frame 47 is lowered to by means of screws 51 and the two replacement cylinders are thus kept cantilevered by the support 34 in one box of the carriage 25, the other box being free.

The rack 40 can then be moved aside to allow axial movement of the carriage handling 18 which is placed on hold next to of cage 1, the free space of the carriage 25 being centered on the clamping plane P '. The device is thus ready to proceed with the removal of the cylinders in service and replacing them with new ones cylinders taken from rack 40 at the time indicated by the rolling program.

It should be noted that, thanks to the independent support working cylinders 4, 4 ', these were able be removed from the insert and placed on the rack 40 without risk of contact with other cylinders.

We can therefore proceed with the verification and maintenance of the rest of the insert including the intermediate cylinder, its chocks and the two lateral support assemblies, without risk of deterioration of the working cylinder. In case of need, the whole insert can be removed and replaced with an overhead crane, slings can be easily hung on the chocks of each intermediate cylinder.

As seen in Figure 7, during cylinder removal or pick-up operations, the main carriage 18 is on the side of the rack 40 opposite the rolling stand 1.

In the case of a tandem rolling mill, each cage of rolling mill would be equipped with a main carriage 18 with side carriage 25 and extractor device 28, each storage rack 40 working cylinders 4 can serve multiple cages.

Thanks to the provisions which have just been described, changing the rolls of a rolling mill, in particular of the "Z-High" type can be realized very quickly and without any risk of deterioration of cylinders, the laminated strip being able to remain engaged and, even continue to scroll.

When the working cylinders or, eventually the complete inserts must be removed for verification and replacement, the cage is open as indicated above, all cylinders being peeled off from each other.

The handling cart 18 is then approached of cage 1, in the position illustrated by the figure 1, the extractor device 28 being moved back towards the right in the figure.

One of the boxes of the carriage 25 is empty and is centered on the median plane P 'of the cage by lateral movement of the carriage 25.

The extractor device 28 is then advanced and allows, as indicated, to remove either the two working cylinders only, i.e. the two inserts and, by retraction of the extractor device 28, the cylinders are placed on the cart 25. The latter is then moved to center the cylinders of replacement which are introduced into the cage in commanding reverse operations.

After the cage is closed, rolling can take over and during this time the handling 18 is moved back into the workshop rectification 20.

When the entire insert has been removed, the extractor device 28 is detached from the chocks intermediate cylinders and can be advanced to place the working cylinders alone in two empty cradles of rack 40 previously centered on the mediator plane of the extractor device 28, the rest of the insert remaining in box 29 of the carriage lateral 25. Therefore, one can proceed to the verification and, possibly, replacement of inserts without risk of damage to the cylinders job.

The extraction device 28 goes back on the carriage 25 and, after unloading, is moved back to clear the rack 40.

This is then moved to center the new working cylinders on the median plane of the extraction device 28, is then advanced to take over the new cylinders.

After spacing the rack 40, the handling 18 can again be advanced until the cage to be ready for a new operation of replacement.

Of course, the invention is not limited to details of the preferred embodiment which comes to be described and which could be modified without deviate from the protective framework defined by claims.

In particular, in the embodiment which has just been described and which relates to a rolling mill Z-High type, the working cylinders are carried, in disassembly position, by forks 62, 62 ' but other support devices could be used to hold working cylinders separated at a constant level from the cylinders intermediate. For example, in a cage with bending cylinders for working cylinders, these cylinders could be used to adjust the level axes of the working cylinders at the axes housings 35 of the support member 34 and, then determine the lowering of either working cylinders to allow it to be load by the support member 34.

Furthermore, given that at the opening of the cage, the lower working cylinder 4 'rests on the lower intermediate cylinder 3 ', you can use the level adjustment means thereof to order the taking over of the cylinder lower work 4. In particular, when the lower support assembly E2 is supported by adjustable shims 17b, these can be used so as to place the axis of the working cylinder lower 4 'at the level of the housing axis 35' from the support member 34, the level of the cylinder higher work 4 being determined, as previously by forks 62.

We then advance the extraction device 28 of so that the two housings 35, 35 'engage on the journals of the two working cylinders 4, 4 'and, by means of shims 17b, the lowering of the assembly E2, the chocks of the intermediate cylinder 3 ', and from the lower support cylinder 2' taking support on their respective rails while the cylinder working lower 4 'is maintained at the same level and supported by the housing 35 'of the body support 34.

Furthermore, it is advantageous to place the extraction device on an auxiliary carriage 25 to ensure immediate replacement of cylinders but, in a simplified arrangement, the handling trolley 18 could carry only one extraction device 28 axially displaceable.

On the other hand, when using a cart auxiliary to several boxes, it is preferable that each of them is equipped with a device extractor. However, it would be possible to place on the handling cart, only one device extractor arranged in a separated position, towards the right in Figure 1, to allow movement of the auxiliary carriage and able to cooperate in turn role with either of the cart boxes lateral.

However, such a device would be more bulky and its slower operation.

Furthermore, in the example shown, the carriage 42 carries two racks 40, 40 'simply placed on the frame 47. It is therefore possible, by means of a lifter, remove one of the racks to replace all the cylinders, the other rack allowing to continue operations according to the rolling. But we could also use just one rack with sufficient number of places for working cylinders.

In addition, as noted above, it is possible, if necessary, to disassemble and replace a single working cylinder or a single insert.

In this case, a rack could be used. storage with a single adjustable level bed base for ensure the replacement of a single working cylinder.

On the other hand, the invention is specially suitable for replacing working cylinders only or complete inserts in a "Z-High" type rolling mill but could be used in any rolling mill using cylinders devoid of chocks.

The reference signs inserted after the technical characteristics mentioned in the claims are intended only to facilitate the understanding and limiting them in no way the scope.

Claims (19)

1. A device for changing rolls in a stand (1) comprising, on either side of a running plane of a band to be rolled:

   two working rolls with parallel axes, respectively upper (4) and lower (4') working rolls, delineating an air gap for the passage of the band, whereas each working roll (4, 4') is extended, at one end at least, by a journal (11),

   two backing-up assemblies, respectively, for each working roll (4), comprising each at least one intermediate roll (3, 3'),

   adjustment means of the levels in relation to the axes of each roll with respect to the stand (1) delineating four levels of disassembly, respectively of both working rolls (4, 4') and of both intermediate rolls (3, 3') for which each working roll (4, 4') is moved away from the corresponding intermediate roll (3, 3'),

   two pairs of rails (8, 8') parallel to the axes of the rolls, arranged on the stand (1) at two constant levels on which rest, respectively, each at its level of disassembly, both intermediate rolls, respectively upper (3) and lower (3') intermediate rolls, each via sliding carrying members (7, 7') for the removal of the corresponding intermediate roll (3, 3').

      the roll changing device comprising:

   a handling device (C ) placed on one side of the stand (1) and comprising of at least one handling and guiding chassis (29) on which are provided two pairs of rails (9, 9') aligned respectively with both pairs of rails (8, 8') of the stand (1),

   at least one extractor device (28) mounted to slide at a constant level on the guiding chassis (29), parallel to the axes of the rolls and movable between a close position of the stand (1) for the disassembly and for the reassembly of the rolls, and an away removal position of the rolls inside the chassis (29),

   means (35) to pick-up each working roll (4, 4') comprising a carrying member (34) mounted on the extractor device (28) and provided with two recesses (35, 35') centred respectively on two axes spaced by a constant distance equal to the distance between the disassembly levels of both working rolls (4, 4'), whereas the level of the carrying member (34) is adjusted so that, in the close position of the extractor device (28), each recess (35, 35') is centred on the axis of each working roll at its disassembly level and engages in a removable way, on the journal (11) of the corresponding working roll (4, 4') by axial displacement of the extractor device (38), whereas the means for adjusting the level of each working roll (4, 4') in order to pick-up, in a cantilever way, the said working roll using the carrying member (34) delineating, after engagement of the journal (11), a relative vertical displacement of the latter with respect to the corresponding recess (35, 35'),

   removable means (37) for hooking each of both intermediate rolls (3, 3'), provided on the extractor device (28) and actuated selectively for the control of the disassembly and of the reassembly of each intermediate roll (3, 3'), by axial displacement, in the corresponding direction, of the extractor device (28), while sliding on the aligned rails (8, 9).
2. A device according to claim 1, characterised in that the carrying member (34) comprises a single part in which are provided two cylindrical bores (35) each constituting a recess into which engages an end portion of the journal (11), whereby each bore (35) is extended, at its lower section on the roll side, by a protruding section, in the shape of a semi-cylindrical cradle and on which rests, in pick-up position, the remaining section of the journal (11).
3. A device according to one of the preceding claims, characterised in that, since each working roll (4, 4') is placed inside an insert comprising two lateral carrying assemblies (13) supported by the intermediate roll (3), the extractor device (28) can determine, selectively, using removable hooking means (37), the assembly and the reassembly of each insert, whereas the working roll (4, 4') is picked up, at its removal level, by the supporting member (34) and the intermediate roll (3, 3') sliding, together with the corresponding lateral carrying assembly (13, 13') on the aligned rails (8, 9), (8', 9').
4. A device according to one of the preceding claims, characterised in that the stand (1) is provided with removable means (62) for backing-up, at least, the upper working roll (4), moveable between a position for backing-up of the said roll (4) at its disassembly level and a retracted position and in that the picking-up of the said working roll (4) by the carrying member (34) is performed while placing the backing-up means (7) in their retracted position, after engagement of the corresponding recess (35) on the journal (11) of the working roll (4).
5. A device according to one of the preceding claims, characterised in that the lower working roll (4') rests in disassembly position on the lower intermediate roll (3') and that the latter is connected to means (17b, 61') for adjusting its own level with respect to the stand (1) and in that the level adjustment of the working roll (4') for centring its axis on the axis of the corresponding recess (35') and its picking-up by the carrying member (34) is performed by adjustment of the level of the lower intermediate roll (3').
6. A device according to one of the preceding claims, characterised in that the extractor device (28) is provided with removable hooking means (37) working together with sections (10) interconnected axially with each intermediate roll (3, 3') to control selectively the sliding motion of the said intermediate roll (3, 3') on corresponding rails (8, 9) (8', 9') under the action of the extractor device (28).
7. A device according to one of the preceding claims, characterised in that the hooking means comprise two fingers (37) mounted to slide transversally to the axes of the rolls on the extractor device (28), whereas the latter can be inserted between both intermediate rolls (3, 3') and means (38) for controlling the motion of one finger (37) at least for hooking at least one intermediate roll (3, 3') by engagement of the said finger into a matching hole provided on a hooking section interconnected axially with the corresponding intermediate roll (3, 3').
8. A device according to one of the preceding claims, characterised in that it comprises at least two guiding chassis (29) each associated with an extractor device (28) and mounted side by side on an auxiliary carriage (25) moveable perpendicular to the axes of the rolls, for the placement of either said chassis (29) in replacement position with the alignment of the corresponding rails (9, 9') with the rails (8, 8') of the stand (1), whereby one of the chassis (29a) is entirely empty initially for the reception of the worn rolls and whereas at least the extractor device (29b) associated with the other chassis (29b) is loaded in advance with new rolls to ensure almost immediate replacement.
9. A device according to claim 8, characterised in that a first chassis (29a) is initially entirely empty, for the reception, at least, of the worn working rolls removed from the stand (1) by the extractor device (28a) associated with the said first chassis (29a) and that a second chassis (29b) is loaded initially with two new working rolls carried by the extractor device (29b) and two intermediate rolls carried by the rails (9, 9') of the said second chassis (29b) for selective replacement, by the extractor device, (28b), of the rolls removed from the stand (1).
10. A device according to one of the preceding claims, characterised in that it comprises a main handling carriage (18) supporting at least one guiding chassis (29) associated with at least one extractor device (28) and mounted to move with respect to the roll stand (1), on fixed rails (44) parallel to the axes of the rolls, between a replacement position in contact with the roll stand (1) and a maintenance position away from the stand (1).
11. A device according to claim 10, characterised in that it comprises at least two guiding chassis (29) each associated with an extractor device (28) and supported by an auxiliary carriage (25) which is mounted to slide on the main handling carriage (18) perpendicular to the axes of the rolls, between at least two positions, respectively, a position of alignment of the rails (9) of each guiding chassis (29) with the rails (8) of the stand (1), whereas the other guiding chassis (29) is moved away from the stand.
12. A device according to claim 11, characterised in that the main handling carriage (18) comprises a plat-form on which is mounted to slide the auxiliary carriage (25) and a linking section (22) placed at one end of the main carriage (18) oriented toward the roll stand (1) and comprising two lateral stanchions on which are mounted rail sections (23, 24) arranged in the alignment of the rails (8) of the stand (1) and on which are aligned the rails (9) of each guiding chassis (29) by displacement of the auxiliary carriage (25).
13. A device for changing rolls according to one of the preceding claims, characterised in that it is associated with a storage rack (40) comprising at least one rest bar (46) on which are provided at least two locations for depositing working rolls each provided with a pair of cradles at a certain distance from one another, centred on an axis parallel to the axes of the rolls of the stand, for depositing, onto the said rest bar (46), a working roll provided, at both its ends, with two journals resting onto the said cradles at a distance from another, whereas one of the said locations is free for depositing a worn working roll and the other of the said locations is occupied by a replacement roll.
14. A device according to claim 13, characterised in that the storage rack (40) is mounted on a carriage (42) movable on rails (44) perpendicular to the axes of the rolls and passing in front of the handling carriage (18) at a distance from the latter, in order to arrange selectively each location for depositing rolls, in a loading or unloading position centred on the median plane of the extractor device.
15. A device according to one of claims 13 and 14, characterised in that the storage rack comprises two superimposed rest bars (46, 46') each carrying at least two adjacent deposit locations, placed at two levels spaced by a distance corresponding to that between the axes of the working roll of the mill, whereby the deposit locations of both rest bars (46) are superimposed in twos for simultaneous reception of a set of two working rolls (4, 4').
16. A device according to one of claims 13 to 15, characterised in that the storage rack (40) is mounted on a chassis (47) mobile in height and associated with means (51) for raising the chassis (7) with respect to the carrying member (34) so that the storage rack (40) picks up at least one worn working roll, also used for lowering the chassis (47) so that the carrying member (34) picks up at least one replacement roll situated on the storage rack (40).
17. A process for changing rolls in a roll stand of the type in which each working roll is placed in an insert comprising an intermediate roll (3) rotating on two chocks (6) and two lateral carrying assemblies (13) supported by the said chocks (6), whereas the latter are provided with means (62) for removable support of the working roll (4), the changing of rolls being made by an extractor device (28) provided on a carrying member characterised in that the extractor device (28) determines selectively the disassembly and the reassembly, either of both working rolls (4, 4'), or of the whole assembly of each insert, with the corresponding working roll, whereas the rolls are held at a fixed disassembly level by the carrying member of the extractor device and whereby the remnant of the insert is supported by rails (8, 9, 8', 9') and slides on the latter under the effect of the extractor device (28).
18. A process for changing rolls using a changing device according to one of claims 13 to 16, characterised in that, after removal of the worn rolls onto the handling carriage (18) and displacement of the latter up to the maintenance position, a storage rack (40) is brought in front of the carriage (18), the carrying member (34) is brought forward on its own in order to place the worn working rolls above the storage rack (40), the rack (40) is lifted, with respect to the carrying member (34) in order to pick up the worn working rolls (4) resting by their journals (11) on two cradles spaced from the storage rack (40), the carrying member (34) is brought back in order to clear the rack (40), the rack (40) is moved laterally in order to centre in the median plane of the extractor device, a location of the said rack (40) carrying replacement rolls placed in advance, the carrying member (34) is brought forward so that the picking up means (35) engages on the journal (11) of at least one working roll (4), the rack (40) is lowered so that the carrying member (34) can pick up the said replacement roll (4), the said carrying member (34) is brought backwards in order to transfer the said replacement roll (4) onto the handling carriage (18), the rack (40) is moved aside laterally and the handling carriage is moved to the close position of the stand (1) ready for the insertion in the latter of the replacement roll (4).
19. A process according to claim 18, characterised in that, once the extractor device (28) has transferred on the handling carriage (18) the assembly consisting of at least one insert comprising a working roll (4), a corresponding intermediate roll (3) and two lateral carrying assemblies (13) and whereas the handling carriage (18) is retracted to its maintenance position, the carrying member (34) alone is moved forward in order to deposit the working roll (34) on the storage rack (40) while leaving the remnant of the insert on the handling carriage (18), maintenance is carried out and, if needed, the intermediate roll (3) and the lateral carrying assemblies (13) on the carriage (18) are replaced, then, after the carrying member (34) has picked up at least one working roll (9), the latter is reinserted inside the corresponding insert, by displacement of the carrying member (34) and after the storage rack (40) has been moved away, the handling carriage (18) is brought back to its position close to the stand (1) for simultaneous insertion inside the said stand of the whole insert with the new working roll.

Images