Device and method for adjusting the distance between straightening rings of a straightening apparatus

Abstract

Adjustment device (10) for adjusting the distance between the straightening rings (101) of a straightening apparatus (100) provided with a rotation shaft (102) on which the straightening rings (101) are mounted, and which is rotatable around an axis of rotation (X). Connection members (11, 21) are interposed between the rotation shaft (102) and the straightening rings (101) to selectively cause, in association with a rotation of the rotation shaft (102), both a rotation of the latter around the axis of rotation (X) and also a reciprocal axial displacement of the straightening rings (101) with respect to a transverse plane (Y).

Description

[0001] “DEVICE AND METHOD FOR ADJUSTING THE DISTANCE BETWEEN STRAIGHTENING RINGS OF A STRAIGHTENING APPARATUS”

[0002] FIELD OF THE INVENTION The present invention concerns a device and a method for adjusting the distance between straightening rings of a straightening apparatus, suitable to straighten oblong products, preferably made of metal, such as, for example, beams, sheet piles, rails, sections with a C, T, or H-shaped cross-section, pipes, or similar products. The aforementioned distance between the straightening rings is sometimes called a “chamber” among the people of skill in the art.

[0003] BACKGROUND OF THE INVENTION

[0004] It is known that an oblong metal product, such as, for example, a beam, a sheet pile, a rail, a metal section with a C, T, or H-shaped cross-section, a pipe or a similar product, as a result of the rolling processes and the corresponding cooling is subject to deformations, or deviations, of its profile, which can determine geometric modifications along its longitudinal extension and / or its cross-section.

[0005] To give the metal product at exit from the rolling line the desired shape and comply with certain dimensional parameters, it is known to make the metal product pass through a straightening apparatus. By ‘straightening’ we mean the joint action of a series of straightening rollers, usually between 8 and 10, sometimes located offset and on different planes, which create a yielding of the metal to obtain a section with desired sizes and geometry.

[0006] A known straightening apparatus is described in Italian patent application for industrial invention N° 102017000145291, corresponding to European patent EP 3.498.390, and comprises at least one rotation shaft on which a straightening roller, or disc, is mounted, which in turn comprises a tubular body, or sleeve, and two straightening rings parallel to each other and mounted in correspondence with the ends of the sleeve, perpendicular to the axis thereof. In order to keep the straightening rings at a certain distance from each other, a tubular shaped spacer element, or spacer, is mounted coaxially and externally to the sleeve, interposed between the straightening rings. The axial size, or length, of the spacer element precisely defines the distance between the straightening rings.

[0007] In the state of the art, when the metal product to be straightened changes, it is usually necessary to change the straightening roller, or at least the straightening rings and the corresponding one or more spacer elements.

[0008] For this purpose, for each metal product to be straightened, a group, or set, is usually prepared, consisting of specific straightening rings and spacer elements of a certain length. Therefore, different metal products to be straightened have different sets of straightening rings and spacer elements.

[0009] This has the disadvantage that, with each change of the metal product to be straightened, the straightening rollers have to be completely removed, and from each of these the straightening rings and the one or more spacer elements used previously have to be completely removed and replaced with those of another set.

[0010] Since each straightening apparatus usually has between 8 and 10 straightening rollers, the time required to change an entire set of straightening rings and the corresponding spacer elements is of the order of a few hours, up to approximately between 3 and 4 hours, during which the straightening apparatus is necessarily stopped, with everything that a downtime of several hours of the corresponding production line implies, with serious repercussions on costs.

[0011] In addition, another disadvantage of the aforementioned state of the art is that, in the event of a possible error by operators in the choice of the set to be installed, all the straightening rings and the corresponding spacer elements of the wrong set have to be removed and replaced with those of another set, with further loss of time and downtime of the corresponding machine, up to a total of even 7-8 hours.

[0012] It is therefore easily understood that the aforementioned operation of changing the straightening rollers, and the associated straightening rings and corresponding spacer elements has the disadvantage of being complex, slow and expensive, and it can lead to risks of errors during the assembly phase, which is currently carried out manually by operators.

[0013] JP Hl l 239821 describes a passage gap adjustment device in a straightening machine, in which a plurality of rotating shafts are attached to the straightening machine’s frame, and a pair of rollers is attached to each rotating shaft, separated from each other in the axial direction. The distance between the rollers can be adjusted by means of a hydraulic device that acts on a system of threaded sleeve collars on which the rollers can move.

[0014] JP H09 248627 and WO 2023 / 128888 describe other solutions of roller adjustment systems in a straightening machine.

[0015] One of the technical problems that the present invention aims to resolve is to reduce as much as possible the amount of time required to install the straightening rings in a straightening apparatus, whenever it is necessary to replace them and / or vary the reciprocal distance between them, in particular when changing the metal product to be straightened.

[0016] Another of the technical problems that the present invention aims to resolve is to no longer have the need to have a set of straightening rings with the corresponding spacer elements for each metal product to be straightened. The invention aims to resolve the technical problems described above with a new and innovative device for adjusting the distance between the straightening rings of a straightening apparatus, and by perfecting a new and innovative method for carrying out this adjustment.

[0017] One purpose of the present invention is therefore to provide a device, and perfect a method, for adjusting the distance between the straightening rings of a straightening apparatus which ensure that, with each change of the metal product to be straightened, the downtime of the straightening apparatus is as short as possible, with a drastic reduction of the time currently required by the state of the art. Another purpose of the present invention is to provide a device, and perfect a method, for adjusting the distance between the straightening rings of a straightening apparatus which ensure that, with each change of the metal product to be straightened, the operation of replacing and adjusting, or setting, the straightening rings is extremely simple and rapid, with advantages also in terms of safety for the operators assigned to the operation.

[0018] Another purpose of the present invention is to provide a device, and perfect a method, for adjusting the distance between the straightening rings of a straightening apparatus that do not always require, with each change of the metal product to be straightened, the removal and replacement of the spacer elements suitable to define the reciprocal distance between at least one pair of straightening rings.

[0019] The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

[0020] SUMMARY OF THE INVENTION

[0021] The present invention is set forth and characterized in the independent claims. The dependent claims describe other characteristics of the present invention or variants to the main inventive idea.

[0022] In accordance with the above purposes and to resolve the technical problem described above in a new and original way, also achieving considerable advantages compared to the state of the prior art, an adjustment device according to the present invention, for adjusting the distance between the straightening rings of a straightening apparatus, wherein the latter is provided with at least one rotation shaft rotatable around an axis of rotation and is configured to support the at least two straightening rings, comprises connection means interposed between the at least one rotation shaft and the at least two straightening rings to cause a rotation of the at least two straightening rings around the axis of rotation in association with a rotation of the at least one rotation shaft.

[0023] In accordance with one aspect of the present invention, the adjustment device further comprises adjustment means interposed between the at least one rotation shaft and the at least two straightening rings to selectively cause an axial displacement of at least one of the at least two straightening rings, preferably both, parallel to the axis of rotation in association with a rotation of the at least one rotation shaft.

[0024] In accordance with another aspect of the present invention, the connection means comprise both a first bushing coaxial to the rotation shaft and connected thereto in order to rotate together with it, and also two second bushings disposed outside of the first bushing and at the same distance from the axis of rotation, wherein the two second bushings are connected to the first bushing so as to be able to both rotate together with it and also slide coaxially to it.

[0025] In accordance with another aspect of the present invention, a first of the two second bushings is disposed on a first side of a transverse plane perpendicular to the axis of rotation, a second of the two second bushings is disposed on a second side of the transverse plane, opposite the first side, and the at least two straightening rings are mounted and attached, at least temporarily, at least one on the first of the two second bushings and at least another on the second of the two second bushings.

[0026] In accordance with another aspect of the present invention, the adjustment means comprise threaded means configured to allow the selective axial displacement of the two second bushings with respect to the first bushing parallel to the axis of rotation.

[0027] In accordance with another aspect of the present invention, the adjustment means also comprise two flanges mounted coaxially to the first bushing, externally with respect thereto and on opposite parts with respect to the transverse plane, which are configured to selectively rotate together with the first bushing, or to remain stationary while the latter rotates together with the rotation shaft.

[0028] In accordance with another aspect of the present invention, the adjustment device also comprises at least one actuation member configured to be selectively activated to keep the two flanges stationary while the first bushing rotates together with the rotation shaft. In accordance with another aspect of the present invention, each of the two second bushings is preferably provided with an annular groove adjacent to the first bushing; in addition, the threaded means comprise both two female threads, each present in a corresponding annular groove of the two second bushings, and also two male threads, each present on the external surface of a corresponding one of the two flanges and engaged with the two female threads. In any case, other mechanical clamping embodiments known to the people of skill in the art are not excluded.

[0029] In accordance with another aspect of the present invention, each of the two flanges and each of the two male threads can be divided into at least two parts, or comprise one or more notches or transverse elastic elements, which allow a relative axial displacement between the at least two parts, but are torsionally rigid, so that the at least two parts of each of the two flanges and of each of the two male threads rotate together rigidly.

[0030] In accordance with another aspect of the present invention, the two female threads and the two male threads are preferably right-hand on one side of the transverse plane and left-hand on the opposite side of the transverse plane, whereby when the two flanges are stationary with respect to the first bushing, the rotation of the latter causes the reciprocal axial displacement of the second bushings and of the at least two straightening rings in opposite senses with respect to the transverse plane.

[0031] In accordance with another aspect of the present invention, the rotation shaft is rotatably supported by two shoulders of the straightening apparatus, and holding means are provided to selectively connect and disconnect at least the adjustment means, the connection means, and the straightening rings associated therewith, to / from at least one of the two shoulders, or both, to allow the straightening rings to be changed.

[0032] In accordance with another aspect of the present invention, an adjustment method for selectively adjusting the distance between at least two straightening rings of a straightening apparatus, wherein the straightening apparatus is provided with at least one rotation shaft rotatable around an axis of rotation and is configured to support the at least two straightening rings, comprises both a first preparation step, in which connection means are interposed between the at least one rotation shaft and the at least two straightening rings to cause a rotation of the at least two straightening rings around the axis of rotation in association with a rotation of the at least one rotation shaft, and also a second preparation step in which adjustment means are interposed between the at least one rotation shaft and the at least two straightening rings to selectively cause an axial displacement of at least one of the at least two straightening rings, preferably of both, parallel to the axis of rotation in association with a rotation of the at least one rotation shaft.

[0033] In accordance with another aspect of the present invention, the at least two straightening rings are disposed on the opposite sides of a substantially median transverse plane perpendicular to the axis of rotation, and the method also comprises an adjustment step in which the adjustment means are selectively activated to cause the reciprocal axial displacement of the at least two straightening rings, approaching or moving away from the transverse plane, using a selective rotation of the rotation shaft.

[0034] In accordance with another aspect of the present invention, the rotation shaft is rotatably supported by two shoulders of the straightening apparatus, and the method also comprises a connection / disconnection step, in which holding means are selectively activated to selectively connect / disconnect with respect to each other at least the adjustment means, the connection means and the straightening rings associated therewith, to / from at least one of the two shoulders, or both, in order to allow the straightening rings to be changed.

[0035] DESCRIPTION OF THE DRAWINGS

[0036] These and other aspects, characteristics and advantages of the present invention will become apparent from the following description of some embodiments, given as a non-restrictive example with reference to the attached drawings wherein:

[0037] - fig. 1 is a schematic, longitudinal section view of an adjustment device according to the present invention, for adjusting the distance between the straightening rings of a straightening apparatus, shown in a first operating position of the adjustment device;

[0038] - fig. 2 is a partial and enlarged schematic view of a longitudinal section of the adjustment device of fig. 1, rotated by 90° with respect to the section of fig. 1;

[0039] - fig. 3 is another longitudinal section of the adjustment device of fig. 1 and of the straightening apparatus on which it is installed, shown in a second operating position of the adjustment device;

[0040] - fig. 4 is another longitudinal section of the adjustment device of fig. 1 and of the straightening apparatus on which it is installed, shown in a resting condition of the adjustment device, after the latter has reached a third operating position and in which the straightening apparatus can resume its normal straightening operations; - fig. 5 is an enlarged detail of fig. 4.

[0041] We must clarify that the phraseology and terminology used in the present description, as well as the figures in the attached drawings, which for ease of representation are not so scale, also in relation as to how they are described, have the sole function of better illustrating and explaining the present invention, their purpose being to provide a non-limiting example of the invention itself, since the scope of protection is defined by the claims.

[0042] To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings.

[0043] DESCRIPTION OF SOME EMBODIMENTS OF THE PRESENT INVENTION With reference to fig. 1, an adjustment device 10 according to the present invention is shown mounted on a straightening apparatus 100, substantially of a known type, for example of the type described in the aforementioned Italian patent application for industrial invention N° 102017000145291. The straightening apparatus 100 comprises at least two straightening rings 101 mounted on a rotation shaft 102 that is rotatable around an axis of rotation X (figs. 1 and 2), as will be described in detail below, which is commanded by a suitable command member consisting of, or comprising, for example, an electric motor and associated transmission means of a known type and not shown in the drawings.

[0044] In particular, by way of example, the rotation shaft 102 is mounted rotatable on a first shoulder 103 (on the right in figs. 1 and from 3 to 5), which in this embodiment is fixed, but which could also be mobile, and is also rotatably guided by a second shoulder 105, which can be either fixed or advantageously mobile, as in the aforementioned Italian patent application.

[0045] In the embodiment shown in figs, from 1 to 5, there are four straightening rings 101, respectively 101a, 101b, 101c and 101 d, and they are disposed in pairs, in a mirror-like manner, with respect to a substantially median transverse plane Y perpendicular to the axis of rotation X (figs. 1 and 2), that is, with the two straightening rings 101a and 101c to the left of the transverse plane Y and the two straightening rings 101b and 10 Id to the right thereof, substantially equally spaced apart from the latter. However, other embodiments, not shown here, but easily understood by a person of skill in the art, can provide that the straightening rings 101 are in any other even number whatsoever, for example 2, 6 or more. Furthermore, a single rotation shaft 102 is represented in the embodiment shown here, but it is understood that the straightening apparatus 100 can comprise a plurality, or series, of rotation shafts 102, for example between 2 and 10, or more, depending on the metal product to be straightened and the type of straightening to be performed. The adjustment device 10 comprises connection means 11 interposed between the rotation shaft 102 and the straightening rings 101, and suitable to cause the rotation of the latter around the axis of rotation X in association with the rotation of the rotation shaft 102.

[0046] In accordance with possible solutions of the present invention, the connection means 11 comprise both a first bushing 12 coaxial to the rotation shaft 101 and connected thereto, for example by means of a first key 13, and also a pair of second bushings 15, respectively one (15a) to the left of the transverse plane Y and one (15b) to the right thereof. The two second bushings 15a and 15b have the same internal and external diameters, are mounted on the first bushing 12 and are connected to the latter by means of two corresponding keys 16a and 16b, respectively, (fig. 2), so that they can both rotate with it and also slide axially with respect to it, as will be described in detail below.

[0047] The straightening rings 101 are attached in pairs, in any known manner, on the second bushings 15, so that at least a first straightening ring 101 is attached on a first of the two bushings 15 and at least a second straightening ring 101 is attached on a second of the two bushings 15. In the embodiment shown here, purely by way of example, the two straightening rings 101a and 101c are attached on the bushing 15a, while the two straightening rings 101b and 10 Id are attached on the bushing 15b.

[0048] Therefore, in this way, in a normal working condition of the straightening rings 101, that is, not one of adjustment, by means of the connection means 11 each rotation of the rotation shaft 101 around its axis of rotation X causes a corresponding rotation of all the straightening rings 101 around the same axis of rotation X.

[0049] In accordance with a characteristic of the present invention, the adjustment device 10 also comprises adjustment means 21 which are also interposed between the rotation shaft 102 and the straightening rings 101 to selectively cause an axial displacement of at least one of the latter, preferably of at least one pair of them, even more preferably all of them, parallel to the axis of rotation X, in association with a rotation of the rotation shaft 102, as will be described in more detail below. Preferably, the straightening rings 101 of the aforementioned at least one pair are disposed on opposite parts with respect to the transverse plane Y.

[0050] In accordance with possible embodiments of the present invention, the adjustment means 21 comprise threaded means 24 which in turn comprise two female threads 22a and 22b each present on a cylindrical surface of a corresponding annular groove 23a and 23b, respectively, created in each of the two second bushings 15a and 15b, respectively, and adjacent to the first bushing 12. The two female threads 22a and 22b are, in a preferred embodiment, one righthand and one left-hand, and advantageously have the same pitch.

[0051] The adjustment means 21 further comprise two flanges 25a and 25b mounted on the first bushing 12 on opposite parts with respect to the transverse plane Y and equidistant therefrom. In particular, each of the two flanges 25a and 25b is mounted on the first bushing 12 so that a selective reciprocal rotation between them around the axis of rotation X is possible, as will be described in detail below. The threaded means 24 also comprise two male threads 26a and 26b present on the external circular surface of each flange 25a and 25b, respectively, and constantly in engagement with a corresponding one of the female threads 22a and 22b, respectively, of the second bushings 15a and 15b, respectively. The two male threads 26a and 26b can have the same pitch and can be one right-hand and one left-hand, similarly to the corresponding female threads 22a and 22b.

[0052] The adjustment means 21 further comprise two discs 27a and 27b, perpendicular to the axis of rotation X and each attached on the more external part of a corresponding one of the two flanges 25a and 25b, respectively, so that they are also equidistant from the transverse plane Y. According to a variant, each disc 27a and 27b can be in a single body with the corresponding flange 25a and 25b, respectively.

[0053] According to another variant, not shown in the drawings, but easily understood by a person of skill in the art, between the discs 27a and 27b and the flanges 25a and 25b, respectively, there can be provided a connection that is created externally, for example by means of a pinion and toothed flange, or any other known mean whatsoever.

[0054] In accordance with possible embodiments, the adjustment device 10 further comprises two actuation members 29a and 29b (figs. 1, 3, 4 and 5) mounted, respectively, on the second shoulder 105 (on the left in the drawings) and on the first shoulder 103 (on the right in the drawings) of the straightening apparatus 100, and therefore on opposite parts with respect to the transverse plane Y. The two actuation members 29a and 29b are configured to each selectively cooperate with one of the two discs 27a and 27b, respectively, and keep the latter stationary, as will be described in detail below. Each actuation member 29a and 29b comprises, for example, a piston 30a and 30b axially mobile parallel to the axis of rotation X and commanded by a corresponding actuator 3 la and 31b, respectively, which can be of any known type whatsoever, for example electromagnetic or fluid-dynamic. Each piston 30a and 30b has a head 32a and 32b configured to selectively engage with a corresponding angular reference 33a and 33b, respectively, present on the external surface of the two discs 27a and 27b, respectively, in correspondence with their periphery. Each angular reference 33a and 33b can be a niche, a recess, a hole, or similar element. In accordance with other possible embodiments, the angular references 33a and 33b may not be present, and in their place, braking means of any type known to the people of skill in the art can be provided to selectively brake the two discs 27a and 27b and then keep them stationary.

[0055] The two pistons 30a and 30b can assume both a resting, or retracted, position, represented in figs. 4 and 5, in which their heads 32a and 32b are spaced apart from the discs 27a and 27b, respectively, and also an operating position (condition represented in figs. 1 and 3), in which they are in engagement with the angular references 33a and 33b, respectively, and keep the two discs 27a and 27b and the two flanges 25a and 25b stationary, so that these do not rotate with respect to the axis of rotation X.

[0056] We must clarify that, in accordance with one aspect of the present invention, the rotation shaft 102, together with the first bushing 12, the second bushings 15 and the straightening rings 101, can rotate around the axis of rotation X, albeit limitedly, regardless of the position assumed by the pistons 30a and 30b, that is, in whatever condition the adjustment means 21 are in, as will be described in detail below.

[0057] According to another variant, it is possible to keep the rotation shaft 102 stationary and rotate the flanges 25a and 25b, possibly by means of the actuation members 29a and 29b, or other suitable mean. In accordance with possible solutions of the present invention, the adjustment device 10 further comprises a conical sleeve 35 (figs. 1 and from 2 to 5) disposed coaxially on the rotation shaft 102, in correspondence with the second shoulder 105 (on the left in figs, from 1 to 5). A thrust member 36 comprising, for example, a hydraulic cylinder, or other type of cylinder, known per se, is associated with the conical sleeve 35 to push it axially with a certain working pressure, parallel to the axis of rotation X, toward the first bushing 12 and exert a certain axial force F on it (schematically represented in fig. 5).

[0058] In accordance with possible solutions of the present invention, between the conical sleeve 35 and the first bushing 12 there is interposed a shaped sleeve 37 (figs, from 1 to 5), which is also in contact with the flange 25a.

[0059] The axial force F exerted by the thrust member 36 on the conical sleeve 35 (from left to right in the drawings) is transmitted, via the shaped sleeve 37, to the flange 25a, which transmits it via the male thread 26a to the female thread 22a, then again to the male thread of the second half of the flange 25a and finally to the bushing 12. The axial force F follows the same path for the flange 25b and the second bushing 15b. In this way, the axial force F exerted by the thrust member 36 on the conical sleeve 35 closes the clearances between the threads of the threads 22a-25a and 22b-25b, and is then unloaded onto a shoulder of the rotation shaft 102 on the first shoulder 103.

[0060] According to another variant, not shown in the drawings but easily understandable for a person of skill in the art, each of the two flanges 25a and 25b and each of the corresponding two male threads 26a and 26b can be divided into two parts, or they can comprise one or more notches or transverse elastic elements, which allow a relative axial displacement between these two parts, but which are torsionally rigid, so that the two parts of each flange 25a and 25b and of each male thread 26a and 26b rotate together rigidly.

[0061] The distance between the straightening rings 101, or chamber, can be detected with a measuring device of a known type and not shown in the drawings, for example of the laser type, a magnetostrictive, resistive, inductive or radar position sensor, or suchlike. The measuring device can be configured to detect the distance between one or more of the straightening rings 101 and one of the two shoulders 103, 105 of the straightening apparatus 100. By means of a closed-loop feedback it is possible to precisely adjust the sizes of the aforementioned chamber.

[0062] In accordance with possible embodiments, generic holding means can be provided, which can be of any known type and are schematically indicated with reference number 40 in figs. 1, 3 and 4. The function of the holding means 40 is to selectively connect and disconnect the adjustment device 10 and the straightening rings 101 associated therewith to at least one of the two shoulders 103 and 105, or to both, in order to allow the straightening rings 101 to be changed. For example, the holding means 40 can selectively connect the adjustment device 10 (in particular at least the connection means 11 and the adjustment means 21) and the straightening rings 101 associated therewith to the second shoulder 105, so that by axially displacing the latter parallel to the axis of rotation X, away from the first shoulder 103, which remains stationary, the adjustment device 10 and the straightening rings 101 also move away from the first shoulder 103, on which the rotation shaft 102 remains supported and pivoted. In this way, it is easy to remove the straightening rings 101 from the corresponding rotation shaft 102 in order to change them.

[0063] The operation of the adjustment device 10 described heretofore, which substantially corresponds to the adjustment method according to the present invention, is as follows.

[0064] The adjustment device 10, in an initial resting condition thereof, is deactivated, that is, not operating (condition schematically represented in figs. 4 and 5), and it allows the straightening apparatus 100 to perform its normal straightening operations. In fact, in the aforementioned resting condition, the actuators 31a and 31b are deactivated and their pistons 30a and 30b are in a retracted position, that is, with their heads 32a and 32b at a distance from the discs 27a and 27b, respectively.

[0065] In this resting condition of the adjustment device 10, a rotation of the rotation shaft 102 around the axis of rotation X causes, as in the prior art, a corresponding rotation of the straightening rings 101 around the latter, without the adjustment device 10 interfering with this rotation. Furthermore, in this resting condition of the adjustment device 10, the flanges 25a and 25b and the discs 27a and 27b also rotate together with the rotation shaft 102. Thanks to the axial force F applied by the thrust member 36, all the clearances are closed and the entire adjustment device 10 rotates rigidly together with the straightening rings 101.

[0066] Suppose that, for example, the straightening rings 101 are initially very close to each other, in the position shown in fig. 1, but with the actuators 31a and 31b deactivated, and that it is necessary to further distance the same straightening rings 101 in order to bring them into a new axial position, for example the one shown in figs. 4 and 5.

[0067] The adjustment first provides an angular positioning step, in which the rotation shaft 102 is rotated, for example slowly, from the angular position in which it is randomly located, to a specific position, in which the angular references 33a and 33b are in correspondence with the pistons 30a and 30b (fig. 5), or by using other suitable braking means. Furthermore, the working pressure, that is, the axial force F, is decreased, by operating on the thrust member 36.

[0068] An actuation step then follows, in which the actuation members 29a and 29b are driven simultaneously so that the heads 31a and 32b of the pistons 30a and 30b enter the angular references 33a and 33b and clamp the discs 27a and 27b and the flanges 25a and 25b in that angular position.

[0069] A distancing step then follows, in which the rotation shaft 102 is slowly rotated in a specific sense of rotation, for example clockwise, as seen from the left in the figures of the drawings, to cause the reciprocal displacement, in this case away from each other, of the second bushings 15a and 15b, and with them of the straightening rings 101, until, for example passing from a second intermediate position shown in fig. 3, the distance D between the straightening rings 101a and 101b becomes the desired one, shown in figs. 4 and 5. This axial displacement is possible because the second bushings 15a and 15b, which rotate together with the rotation shaft 102, are “screwed” with their female threads 22a and 22b onto the corresponding male threads 26a and 26b of the flanges 25a and 25b, which are held stationary by the actuation members 29a and 29b. In fact, the female threads 22a and 22b have an opposite sense and the same pitch, whereby the two second bushings 15a and 15b move away from, or approach, each other symmetrically.

[0070] It is clear that a rotation of the rotation shaft 102 in a specific opposite sense of rotation, for example counterclockwise, as seen from the left in the figures of the drawings, will cause the reciprocal displacement, in this case approaching each other, of the second bushings 15a and 15b, and with them of the straightening rings

[0071] 101, up to a new desired distance between the straightening rings 101a and 101b. Alternatively, it is possible to keep the rotation shaft 102 stationary and rotate one or both of the flanges 25a and 25b.

[0072] Once the new desired position of the straightening rings 101 has been reached, there is a disengagement step, in which the actuation members 29a and 29b are taken back to their initial position, or the braking means, if present, are deactivated, whereby the adjustment device 10 as a whole returns to its resting condition. The working pressure, that is, the axial force F, is also returned to the initial value and the straightening apparatus 100 is ready to resume the normal work cycle.

[0073] As can be easily understood, with the present invention the entire step of adjusting the distance between the straightening rings 101 described above requires little time, of the order of minutes rather than hours, with great advantages in terms of reducing machine downtime.

[0074] In the event that, instead of changing the distance between the straightening rings 101 it is necessary to replace them completely, for example in order to install others with different diameter and / or shape, a process for rapidly changing them will be activated, for example as described in the aforementioned Italian patent application, whereby the actuation member 29b is driven so as to clamp the disc 27b on the second shoulder 105, which in this case has to be mobile, while the first shoulder 103 remains stationary. The second shoulder 105 is then moved away from the fixed shoulder 103, dragging with it the entire assembly consisting of the bushings 12 and 15 and the straightening rings 101, together with the flanges 25a and 25b and the discs 27a and 27b, while the rotation shaft 102 still remains stationary and rotatably supported by the first shoulder 103, which remains stationary.

[0075] When the adjustment means 21 and / or the straightening apparatus 100 are associated with the holding means 40 (figs. 1 , 3 and 4), the method also comprises a connection / disconnection step, in which the holding means 40 are selectively activated to selectively connect / disconnect with respect to each other the adjustment device 10 (in particular at least the connection means 11 and the adjustment means 21) and the straightening rings 101 associated therewith, to / from one or both of the shoulders 103 and 105 that support the rotation shaft 102, to allow the straightening rings 101 to be changed.

[0076] It is clear that modifications and / or additions of parts, or of steps, may be made to the adjustment device 10 and to the associated method as described heretofore, without thereby departing from the field and scope of the present invention, as defined by the claims. It is also clear that, although the present invention has been described with reference to some specific example embodiments, a person of skill in the art will be able to achieve other equivalent forms of apparatuses for adjusting the distance between the straightening rings of a straightening apparatus, and of associated methods, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.

[0077] In the following claims, the sole purpose of the references in brackets is to facilitate their reading and they must not be considered as restrictive factors with regard to the field of protection defined by the claims.

Claims

CLAIMS1. Adjustment device (10) for selectively adjusting the distance between at least two straightening rings (101) which are mounted on a rotation shaft (102) that is rotatable around an axis of rotation (X) of a straightening apparatus (100), wherein said adjustment device (10) comprises connection means (11) interposed between said rotation shaft (102) and said at least two straightening rings (101) to cause a rotation of said at least two straightening rings (101) around said axis of rotation (X) in association with a rotation of said rotation shaft (102), wherein said adjustment device (10) comprises adjustment means (21) interposed between said rotation shaft (102) and said at least two straightening rings (101) to selectively cause an axial displacement of at least one of said at least two straightening rings (101), preferably both, parallel to said axis of rotation (X) in association with a rotation of said rotation shaft (102), characterized in that said connection means(11) comprise both a first bushing (12) coaxial to said rotation shaft (102) and connected thereto in order to rotate together with it, and also two second bushings(15) disposed outside of said first bushing (12) and at the same distance from said axis of rotation (X), wherein said two second bushings (15) are connected to said first bushing (12) so as to be able to both rotate together with it and also slide coaxially to it, each of said straightening rings (101) being attached to a corresponding one of said second bushings (15), and in that said adjustment means (21) comprise threaded means (24) configured to allow the selective axial displacement of said two second bushings (15) with respect to said first bushing(12) parallel to said axis of rotation (X).

2. Adjustment device (10) as in claim 1, characterized in that a first (15a) of said two second bushings (15) is disposed on a first side of a transverse plane (Y) perpendicular to said axis of rotation (X), a second (15b) of said two second bushings (15) is disposed on a second side of said transverse plane (Y), opposite said first side.

3. Adjustment device (10) as in claim 1 or 2, characterized in that said adjustment means (21) also comprise two flanges (25a, 25b) mounted coaxially to said first bushing (12), externally with respect thereto and on opposite parts with respect to said transverse plane (Y), which are configured to selectively rotate together with said first bushing (12), or to remain stationary while the latter rotatestogether with said rotation shaft (102).

4. Adjustment device (10) as in claim 3, characterized in that it also comprises at least one actuation member (29a, 29b) configured to be selectively activated to keep said two flanges (25a, 25b) stationary while said first bushing (12) rotates together with said rotation shaft (102).

5. Adjustment device (10) as in one or the other claim from 1 to 4, characterized in that each of said two second bushings (15) is preferably provided with an annular groove (23a, 23b) adjacent to said first bushing (12), and in that said threaded means (24) comprise both two female threads (22a, 22b), each present in a corresponding annular groove (23a, 23b) of said two second bushings (15), and also two male threads (26a, 26b), each present on the external surface of a corresponding one of said two flanges (25a, 25b) and engaged with said two female threads (22a, 22b).

6. Adjustment device (10) as in claim 5, characterized in that each of said two flanges (25a, 25b) and each of said two male threads (26a, 26b) are divided into at least two parts, or comprise one or more notches or transverse elastic elements, which allow a relative axial displacement between said at least two parts, but are torsionally rigid, so that said at least two parts of each of said two flanges (25a, 25b) and of each of said two male threads (26a, 26b) rotate together rigidly.

7. Adjustment device (10) as in claim 5 or 6, characterized in that said two female threads (22a, 22b) and said two male threads (26a, 26b) are preferably righthand on one side of said transverse plane (Y) and left-hand on the opposite side of said transverse plane (Y), whereby when said two flanges (25a, 25b) are stationary with respect to said first bushing (12), the rotation of the latter causes the reciprocal axial displacement of said second bushings (15) and of said at least two straightening rings (101) in opposite senses with respect to said transverse plane (Y).

8. Adjustment device (10) as in any claim hereinbefore, wherein said rotation shaft (102) is rotatably supported by two shoulders (103, 105) of said straightening apparatus (100), characterized in that holding means (40) are provided to selectively connect / disconnect at least said adjustment means (21), said connection means (11) and said straightening rings (101) associated therewith, to / from at least one of said two shoulders (103, 105), or both, to allow said straightening rings(101) to be changed.

9. Adjustment method for selectively adjusting the distance between at least two straightening rings (101) which are mounted on a rotation shaft (102) that is rotatable around an axis of rotation (X) of a straightening apparatus (100), wherein said method comprises a first preparation step, in which connection means (11) are interposed between said rotation shaft (102) and said at least two straightening rings (101) to cause a rotation of said at least two straightening rings (101) around said axis of rotation (X) in association with a rotation of said rotation shaft (102), the method comprising a second preparation step in which adjustment means (21) are interposed between said rotation shaft (102) and said at least two straightening rings (101) to selectively cause an axial displacement of at least one of said at least two straightening rings (101), preferably both, parallel to said axis of rotation (X) in association with a rotation of said at least one rotation shaft (102), wherein said axial displacement of said at least two straightening rings (101) is obtained by acting on threaded means (24) that allow for the selective axial displacement of two second bushings (15) on which said straightening rings (101) are mounted with respect to a first bushing (12) which is connected to said rotation shaft (12) and is rotating therewith.

10. Method as in claim 9, wherein said at least two straightening rings (101) are disposed on the opposite sides of a substantially median transverse plane (Y) perpendicular to said axis of rotation (X), characterized in that it also comprises an adjustment step, in which said adjustment means (21) are selectively activated to cause the reciprocal axial displacement of said at least two straightening rings (101), approaching or moving away from said transverse plane (Y), using a selective rotation of said rotation shaft (102).

11. Method as in claim 9 or 10, wherein said rotation shaft (102) is rotatably supported by two shoulders (103, 105) of said straightening apparatus (100), characterized in that it also comprises a connection / disconnection step, in which holding means (40) are selectively activated to selectively connect / disconnect with respect to each other at least said adjustment means (21), said connection means(11) and said straightening rings (101) associated therewith, to / from at least one of said two shoulders (103, 105), or both, to allow said straightening rings (101) to be changed.

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