EP3826784A1

EP3826784A1 - Method and apparatus for supplying elongated metal elements

Info

Publication number: EP3826784A1
Application number: EP19758518.5A
Authority: EP
Inventors: Simone Rupoli
Original assignee: Schnell SpA
Current assignee: Schnell SpA
Priority date: 2018-07-24
Filing date: 2019-07-22
Publication date: 2021-06-02
Also published as: AU2019311408A1; WO2020021582A1; JP2022503459A; IT201800007479A1

Abstract

The method for bending elongated metal elements, in particular metal bars, firstly provides for setting for an element (2) to be supplied an optimal orientation (21) of a theoretical cross-section (20), with respect to a longitudinal axis, then inserting the element (2) into a drive group (3) along a supply direction (A) coinciding with the longitudinal axis of the element (2). The method further provides for detecting an actual orientation (22) of the element (2) supplied with respect to the longitudinal axis at a cross-section (20) by means of a detection device (4) and for processing by means of processing means associated with the detection device (4) any deviation of the actual orientation (22) detected with respect to the optimal orientation (21) of the element (2). An orientation device (5) is then operated so as to tighten and rotate the element (2) around the longitudinal axis by an angle such as to compensate for the processed deviation, so as to orient the element (2) according to the optimal orientation (21).

Description

METHOD AND APPARATUS FOR SUPPLYING ELONGATED METAL ELEMENTS

Technical Field

[01] The present invention relates to a method and an apparatus for supplying elongated metal elements, in particular metal profiles and rods in bars, for example intended for a bending or calendering cycle.

Prior Art

[02] Apparatuses are known for processing elongated metal elements, in particular metal profiles and similar products in bars, which comprise at least one drive group and at least one bending group.

[03] In particular, the drive group generally consists, for example, of one or more pairs of counter-rotating wheels, at least one of which is motorized, opposed with respect to a supply direction of the elements to be supplied.

[04] The bending group, on the other hand, consists, for example, of a bending head comprising a central mandrel, around which a bending pivot can be operated in rotation, on a respective bending plane. The elements supplied to the bending head can thus be subjected to one or more bending operations in succession, in order to produce shaped products, open or closed profile brackets, therefore flat products, or three-dimensional products intended for scaffolding of building structures.

[05] The patent EP2714296 of the same Applicant illustrates for example an apparatus for making two-dimensional and three-dimensional brackets, comprising guide means for supplying a metal rod along a supplying direction, a first bending group comprising a first central bending mandrel and a first eccentric bending pivot rotatable about the first central mandrel to bend the metal rod on a worktable, a second bending group comprising a second central mandrel and a second bending pivot movable around the second central mandrel to bend the metal rod on a bending plane inclined with respect to the worktable.

[06] In the production of flat products, in particular brackets, shaped and calendered products starting from metal elements, such as bars or rods, there is the problem of guaranteeing an acceptable tolerance on the coplanarity of the finished piece. In practice, the elements naturally tend to rotate around their own longitudinal axis while they are supplied by the drive and bending group and, therefore, following this spontaneous rotation, the bending result can deviate from the coplanarity beyond the tolerance considered acceptable.

[07] For example, the application EP 3225322 illustrates a bending method and apparatus for manufacturing pieces bent in several dimensions.

Disclosure

[08] The object of the present invention is to solve the aforementioned problems by devising a method and an apparatus for allowing the supply of elongated metal elements, intended to 29.371 . PC.19_..EN

be processed for example for the production of shaped products, such as brackets or shaped products in general, for the scaffolding of buildings.

[09] Another object of the present invention is to provide an apparatus for supplying elongated metal elements, of simple constructive and functional conception, having a safe and reliable use, as well as a relatively inexpensive cost.

[10] The aforementioned objects are achieved, according to the present invention, by the method for supplying elongated metal elements according to claims 1 and 5 and by the apparatus for supplying the same elements according to claim 8.

[1 1] According to a prerogative of the invention it is therefore possible to control the supply of elongated metal elements, so as to allow their processing, in particular the bending or calendering, in an optimal manner.

[12] According to the invention, the method provides for identifying or setting, in a control unit of the apparatus for processing an elongated metal element, for the same element, an optimal orientation of a theoretical cross-section with respect to a fixed reference system, integral with the apparatus supplying the element itself.

[13] The aforementioned optimal orientation represents the orientation of the aforementioned theoretical section, which corresponds to the minimum tendency of the element to rotate about its own longitudinal axis when it is supplied by a drive group of the supplying apparatus and is possibly subjected to bending operations.

[14] In fact, when an elongated metal element is inserted and supplied by the members, generally opposite wheels of the drive group, the element itself is subjected to opposing thrust actions by the aforesaid members, which generate a corresponding friction force e, therefore, a towing force in a supply direction corresponding to the motion of the drive members. It can be observed that the element towed along the aforesaid supply direction is usually subjected to a spontaneous rotation about its own longitudinal axis, which can be contrasted precisely by the aforesaid friction action, therefore by the thrust with which the drive members act by contact on the element itself.

[15] It has been found that this tendency is also influenced by the degree of stability with which the section itself is oriented with respect to the driving members themselves. More precisely it is possible to identify, even only empirically or theoretically, a more stable orientation, therefore optimal, among any other possible orientation, of the section of the element, when it is interposed between the drive members.

[16] In other words, the aforementioned optimal orientation represents the orientation assumed by the element engaged between the aforesaid members of the drive group, which corresponds to the maximum resistance to rotation, generated by contact with the same members.

[17] In practice, in the case of metal rods of usual use, which are generally provided peripherally 29.371 . PC.19_..EN

with ribs, and therefore of protrusions which are arranged for example longitudinally, the aforementioned optimal orientation is represented by the orientation following which the aforesaid ribs react to the contact with the drive members by means of a torque reaction to the rotation about its own longitudinal axis.

[18] A greater resistance of the element to the spontaneous axial rotation, favourable to make the orientation of the element itself stable, and therefore optimal, can in particular be determined by the onset of a resistant torque, the amount of which, in particular in the case in which the driving members have a flat contact profile, is in turn given by the amount of the opposing thrust actions exerted by the drive members on the element itself, multiplied by the distance between the actions.

[19] The method therefore provides for inserting the element to be supplied into a drive group provided with the aforesaid driving members, along a supply direction coinciding with the longitudinal axis of the element itself, as well as detecting, by means of a detection device, an actual orientation of the inserted element with respect to the same fixed reference system at a detection plane.

[20] This detection, to determine the actual orientation, can be performed while the element is stationary or moving along the supply direction.

[21 ] According to the invention, a processing step is carried out, preferably in real time, by means of processing means associated with the detection device and configured to process, precisely, the possible deviation between the actual orientation detected by the detection device and the set optimal orientation, for example calculated, for the same element.

[22] If the aforesaid detection device includes image detection means, the detection of the actual orientation of the element can include the step of reconstructing, by means of the aforementioned processing means, an instantaneous image of the detected section of the element at the detection plane.

[23] Furthermore, if the aforesaid detection device includes image detection means, the step of processing any deviation between the actual orientation and the optimal orientation may include a step of comparison between the aforementioned reconstructed instantaneous image and a set image, relating to the aforementioned optimal orientation.

[24] According to a prerogative of the invention, the element is therefore tightened at at least one section, freed from possible tightening possibly operated by other members of the apparatus, in order to be rotated by means of an orientation device, about the same longitudinal axis, by an angle such as to compensate for the deviation previously elaborated, so as to position the element according to the aforementioned optimal orientation.

[25] The element can then be tightened again by the members of the apparatus, for example the drive members, and released by the tightening of the orientation device, in order to be 29.371 . PC.19_..EN

supplied by the drive group and subjected to a determined processing cycle, for example one or more bendings interspersed with the developments of the element.

[26] Advantageously it is possible to provide that the detection device operates the detection, for respective sections passing through the detection plane, of further actual orientations, during the successive phases of supplying of the element itself, at predetermined time intervals or continuously, to monitor any deviation of the orientation from the optimal orientation detected for the same sections.

[27] If a deviation is detected, in particular a deviation beyond a predetermined threshold, the method may require to interrupt the supply of the element and restoring the optimum orientation, according to the steps described above.

[28] Thanks to the initial setting of an optimal orientation, at which the tendency of the element to rotate around its own axis is minimal, the same element can be positioned thanks to the orientation device according to this optimal orientation, so as to obtain after following processing, for example, finished parts falling within the shape tolerance considered admissible for the specific production cycle.

[29] According to a particular aspect of the invention, the optimal orientation for a given element to be supplied can be calculated, for example by the same processing means, considering the moment of inertia, in particular the minimum moment of inertia, of a theoretical section of the element for example with respect to a barycentric axis.

[30] In practice, the method provides for identifying, through the calculation or experience of previous work cycles, the orientation, which, based on the actual geometry of the section of the element, offers greater resistance to rotation around its own longitudinal axis.

[31] This greater resistance, as previously mentioned, can be generated by the occurrence of a torque resistant to rotation, determined by the fact that the opposite thrust actions of the driving members, due to the contact of particular irregularities of the profile of the element itself, for example ribs, are arranged spaced and parallel.

[32] The method also provides for the detection of the actual orientation of the element, in order to identify, calculate or determine the direction of the spontaneous rotation of the element.

[33] Advantageously, it is also possible to provide that the orientation device is used to keep an intercepted section tight during a bending step of the element being processed, so as to avoid undesired displacements, in particular rotations, from the optimal orientation. These rotations can be caused by the irregularity of the contact between the element itself and the operating members, for example the bending members, determined by the apparently random positioning of the irregularities of the profile of the element, for example of the typical ribs of the metal rod.

[34] Alternatively or in addition, it is possible to operate the orientation device before each bending step, to bring back the element being processed towards the optimum orientation 29.371. P _.

or, in any case, towards a desired orientation.

[35] In any case, the orientation device can also be used to make three-dimensional pieces, making the controlled rotation of the element being processed as well as re-establishing the optimal orientation following undesired rotations of the element being processed.

[36] Preferably, the step of actuating the orientation device is preceded by a step in which each guiding or towing means adapted to engage the element to be fed releases the element itself, so as to allow the subsequent controlled rotation for positioning according to the optimal orientation.

[37] Preferably the element to be supplied is a metal bar or a metal rod, for example of a predetermined size.

[38] According to an alternative solution of the method according to the invention, it is possible to provide that the apparatus according to the invention identify the aforementioned optimal orientation of the element to be supplied by monitoring next detections of the actual orientation, by means of a sort of self-learning. In practice, the control unit of the apparatus, by means of the aforementioned detection device, monitors the actual orientation of the metal element, identifying a stable or more stable orientation between the aforementioned detections.

[39] For example, the aforementioned stable orientation may correspond to an orientation of the section of the element, which, once reached, remains substantially unchanged for the element being supplied.

[40] The method can also preferably provide for saving this stable orientation, identified through successive readings, for each type of element, so as to be able to set it later in a processing cycle that uses the same type of element.

[41] Furthermore, the method according to the invention can provide for inserting an elongated element in a drive group provided with driving members along a supply direction, detecting a first initial actual orientation of the elongated element, stationary or in motion along the supply direction, and detecting, for example after a predetermined time interval or before or after a first bending, at least one further actual orientation. Finally, the method provides for processing, by processing means of the control unit of the apparatus, a possible deviation between the first detection and the second detection, indicative of a corresponding rotation of the element itself along its longitudinal axis coinciding with the aforesaid supply direction. As in the previous case, the element is blocked, tightened by an orientation device and rotated so as to compensate for this deviation, so as to restore the initial orientation, or in any case a desired orientation.

[42] The apparatus that implements the method according to the invention therefore comprises a drive group, provided with driving members, for supplying an element along a feeding direction, which coincides with the longitudinal axis of the element itself. Thanks to the 29.371 . PC.19_..EN

provision of the aforementioned processing means of the detection device and of the orientation device the apparatus allows the detection of the actual orientation of the element arranged on the apparatus to be supplied, and its positioning according to the optimal orientation in any case identified, pre-established by the operator, calculated or identified by monitoring subsequent actual orientations through the detection device.

[43] In this way it is possible to minimise the consequences of the natural tendency of the element to rotate during the advancement step, at the same time ensuring the production of pieces having completely acceptable shape tolerances.

[44] Preferably the detection device is arranged next to the drive group, where the element is initially inserted to be subsequently supplied.

[45] Alternatively, the detection device, like the orientation device, can be arranged at will along the supply axis of the element.

[46] The same detection device can be for example an optical device, in particular a laser gauge or a profilometer, or a mechanical device, for example a mechanical probe.

[47] The orientation device is preferably made of a rotatable pincer member.

[48] The provided orientation device can perform both the function of orienting the element at the beginning of the work cycle, and, for example, the function of rotating the element during the bending cycle, intervening between successive bending steps, to produce, in particular, three-dimensional pieces.

Brief description of drawings

[49] The details of the invention will become more evident from the detailed description of a preferred embodiment of the apparatus for supplying elongated metal elements, as well as of the method implemented by the same apparatus, illustrated only by way of non-limitative example in the accompanying drawings, where:

Figures 1 to 4 respectively show a front view of an apparatus for supplying metal elongated elements according to the invention, in successive operating steps;

Figures 5 to 7 and 8 to 10 respectively show a schematic front view, in perspective and side view of the same apparatus in different operating steps.

Embodiments of the invention

[50] With particular reference to Figures 1 to 10, the reference numeral 1 generally indicates an apparatus for supplying elongated metal elements 2, in particular metal profiles and rods.

[51 ] For each element 2 to be fed, provided with a cross-section 20, may be known or calculated by processing means associated with the apparatus 1 itself, an optimal orientation 21 with respect to its own longitudinal axis, at which the element itself has a minimum tendency to spontaneous rotation around the same longitudinal axis.

[52] For example, this optimal orientation 21 can be calculated on the basis of the moment of inertia of section 20, in practice of a theoretical section of the element 2, with respect to a 29.371. P _.

barycentric axis or, in any case, it can represent the orientation at which the same element puts up the maximum resistance to the rotation around its own longitudinal axis.

[53] In the absence of a calculated optimal orientation 21 , a desired orientation or inferred from the experience for the specific type of element 2 may be considered. Alternatively, as described below, the detection of an initial orientation can act as an optimal orientation, that is, a reference for the production cycle.

[54] The apparatus 1 therefore comprises a drive group 3, a detection device 4 and an orientation device 5, adapted to bring together the element 2 arranged for the following processing, according to the aforementioned optimum orientation 21 or in any case to a desired orientation or reference.

[55] The apparatus further comprises, preferably, a cutting group and a bending group, of a known type, not shown in the figure for simplicity. In particular, the apparatus may comprise, instead of a traditional bending group, or in addition to it, a calendering group.

[56] The drive group 3 may comprise, in a known manner, at least one pair of counter-rotating wheels 30, 31 opposite to a supply direction A along which the element 2 is inserted and subsequently supplied.

[57] In particular, each pair of opposite wheels 30, 31 tangentially defines an insertion channel for an element 2 to be supplied and preferably comprises, in a known manner, a grooved peripheral edge, to engage the element 2 so interposed.

[58] The element 2 can be preferably inserted through a series of guide members 32, for example pairs of guide wheels opposite to the supply direction A, usually neutral.

[59] The detection device 4 comprises at least one detecting member, for example of the optical or mechanical type, configured to detect the orientation of the element 2 at a detection zone, preferably a detection plane 6. In Figure 1 , for example, the trace of the aforementioned detection plane 6 is indicated with the number 6.

[60] In practice, the detection device 4, which can be made for example by means of a video camera associated with an image processing unit, a laser gauge or a profilometer, in case of an optical type, or a mechanical probe, in case of a mechanical type, is capable of detecting the orientation of a section 20 which crosses the aforesaid detection plane 6, with respect to the longitudinal axis of the element 2, in a fixed reference system, such as for example the fixed frame of the apparatus 1 .

[61] The detection device 4 is advantageously arranged along the series of operating members of the apparatus 1 , arranged to interact along the supply direction A with the element 2, so as to detect the actual orientation 22 of the detected section 20 and, therefore, substantially of the element 2, in an initial processing step, when the element 2 is inserted in the drive group 3.

[62] It is in fact preferable for the detection device 4 to be as close as possible to the drive group 29.371. P _.

3, for example near the guide members 32, so as to be able to detect the actual orientation 22 which the element 2 takes at said organs.

[63] In practice, for example, the detection device 4 can detect the actual orientation 22 of the element 2 at the detection plane 6, by detecting, in particular, some portions of the section 20 of the same element 2 which represent irregularity with respect to a perfectly axisymmetric profile, in particular circular. By following these irregularities during the supply of the element 2 along the supply direction A it is therefore possible to detect the direction and amount of a possible rotation, generally not desired, of the element 2 supplied around the respective longitudinal axis.

[64] For example, in the case of metal rods or metal bars usually used for construction, such irregularities may include ribs 2a, in particular longitudinal, and/or ribs 2b (see in particular Figures 1 , 5, 6, 8, 9).

[65] In practice, in the case of rods or bars the aforementioned optimum orientation 22 is represented by the orientation following which the ribs 2a react to contact with the drive members 30, 31 by means of a torque reaction to the rotation about its own longitudinal axis.

[66] In this case, the greater resistance of the element 2 to the spontaneous axial rotation, favourable to make the orientation of the element 2 itself stable, and therefore optimal, can in particular be determined by the onset of a resistant torque, whose extent derives in turn from the extent of the opposing thrust actions F exerted by the drive members 30, 31 on the element itself, multiplied by the distance d between the thrust actions F. In this case, as shown in Figure 5, the optimum orientation 21 corresponds to an orientation of an axial plane containing the ribs 2a, inclined by an angle a with respect to a median longitudinal plane P orthogonal to the contact areas of the drive members 30 ,31.

[67] The orientation device 5 can be made by means of a gripping member, for example a pincer member, operable in rotation, in order to tighten the element 2 at a respective section and operate its controlled rotation around its longitudinal axis.

[68] The orientation device 5 can therefore be made for example by means of a pair of clamps 50, 51 , preferably suitably shaped, which are opposite with respect to the supply direction A and, therefore, to the channel for inserting the drive group 3, alternately movable between a release condition and a tightening condition of an element 2 to be supplied. Moreover, the clamps 50, 51 are usefully configured to be operated in rotation, in a controlled manner, as described before.

[69] The clamps 50, 51 can advantageously include a shaped clamping seat, for example having a triangular or V-shaped profile.

[70] The apparatus 1 further comprises processing means, associated with the orientation device 5 and preferably forming part of a control unit of the apparatus itself, suitable for 29.371 . PC.19_..EN

determining the possible deviation of the actual orientation 22 detected by the optimum orientation 21 initially set for the particular element 2 to be processed or by a desired orientation, as described below.

[71] Following the calculation of this possible deviation, the orientation device 5 can therefore be actuated correspondingly in a controlled manner, in order to rotate the element 2 around the respective longitudinal axis in the appropriate direction and thus arrange it according to the optimum orientation 21 set. The controlled activation of the orientation device 5 therefore is necessary to ensure that the element 2 is oriented so as to present the slightest tendency to any spontaneous and uncontrolled rotation.

[72] The method for supplying metal elongated elements according to the invention, as well as the operation of the apparatus that operates it, can be easily understood from the preceding description.

[73] In a step of preparation of a new work cycle, the element 2 can be inserted in the insertion channel of the drive group 3, along the supply direction A.

[74] For this element 2 an optimal orientation 21 is then set in the control unit of the apparatus 1 or identified, being characteristic of the particular cross section 20 of the element 2 itself.

[75] The detection device 4 detects the actual orientation 22 of the element 2 at the detection plane 6 and transmits this data to the associated processing means.

[76] The aforementioned processing means then calculate the possible deviation between the actual orientation 22 and the optimal orientation 21.

[77] While the element 2 is stationary, inserted in the insertion channel of the drive group 3, the orientation device 5 can operate the tightening of the element 2 itself at a respective section intercepted by the clamps 50, 51 . In this case, any other present gripping, guiding or driving members release the element 2 so that it is free to be rotated.

[78] Based on the deviation previously calculated by the processing means, the orientation device 5 is operated in rotation, so as to position the element 2 according to the optimum orientation 21.

[79] At this point, the orientation device 5 can release the element 2, in order to allow the drive group 3, as well as any other member involved, to engage the same element 2, supplying it to the downstream processing group, preferably to a bending head and possibly a cutting unit, to make two-dimensional or three-dimensional products according to requirements, or to a calendering group.

[80] According to an alternative solution, advantageous in particular in the case in which it is not possible to set an optimal orientation 21 in an initial phase, the method according to the invention can provide for inserting the elongated element 2 in the drive group 3 along the supply direction A, of detecting a first actual orientation 22 of the element 2 itself. This first actual orientation 22 can be detected just before or just after carrying out a first bending on

Claims

29.371 . PC.19_..EN

the element 2.

[81] Then the method provides to detect at least one further actual orientation 22, for example before carrying out a second bending of the element 2.

[82] Finally, the method provides for processing, by means of processing means, a possible deviation between the first detection and the second detection, indicative of a corresponding rotation of the element 2 itself along its own longitudinal axis coinciding with the aforesaid supply direction A.

[83] As is the case with the previously described method solution, the element 2 is therefore stopped, tightened by the orientation device 5 and rotated so as to compensate for this deviation, so as to restore the first orientation 22 initially detected, or however a desired orientation device.

[84] In the practical embodiment of the invention, the materials used, as well as the shape and the dimensions, may change according to requirements.

[85] Should the technical features mentioned in any claim be followed by reference signs, such reference signs were included strictly with the aim of enhancing the understanding of the claims and hence they shall not be deemed restrictive in any manner whatsoever on the scope of each element identified for exemplifying purposes by such reference signs.

29.371. PC.19 _. EN

Claims

1. Method for supplying elongated metal elements, in particular metal bars, for example designed for a bending cycle, characterized in that it comprises the steps of:

a. setting in a control unit of an apparatus for supplying a said element (2) or identifying for said element (2) to be supplied, an optimal orientation (21 ) of a theoretical cross section, with respect to a respective longitudinal axis;

b. inserting said element (2) into a drive group (3) along a supply direction (A) coinciding with said longitudinal axis;

c. detecting at a detection plane (6) an actual orientation (22) of a cross section (20) of said inserted element (2), with respect to said longitudinal axis, by means of a detection device (4);

d. processing by means of processing means associated with said detection device (4) any deviation of said actual orientation (22) detected with respect to said optimal orientation (21 ) of said element (2);

e. tightening and rotating by means of an orientation device (5) said element (2) tightened around said longitudinal axis by an angle such as to compensate said processed deviation, so as to orient said element (2) according to said optimal orientation (21 );

f. releasing said element (2);

g. supplying said element (2) along said supply direction (A) to achieve at least one processing step,

said step a. of identifying a said optimal orientation (21 ) comprising the step of supplying said element (2) and carrying out the monitoring of subsequent said actual orientations (22) of said element (2) at said detection plane (6), identifying and storing a stable orientation to be considered optimal, among said actual orientations (22) detected, corresponding to an actual orientation (22) of said element (2) which, once achieved, remains substantially unchanged for said element (2) during supply step or in any case it opposes the maximum resistance to a spontaneous rotation of said element (2) around said longitudinal axis; or

said step a. of setting said optimal orientation (21 ) taking place by means of said processing means, calculating the moment of inertia of said theoretical section (20) with respect to a barycentric axis or calculating the orientation of said element (2) which opposes maximum resistance to rotation of said element (2) about its longitudinal axis during supply step by said drive group (3).

2. Method according to claim 1 , characterized in that said step of setting said optimal orientation (21 ) by calculating the moment of inertia of said theoretical section (20) with respect to a barycentric axis provides for calculating the minimal moment of inertia of said theoretical section (20) with respect to said barycentric axis.

29.371 . PC.19_..EN

3. Method according to claim 1 or 2, characterized in that said step a. of setting said optimal orientation (21 ) takes place by means of said processing means, finding said optimal orientation (21 ) from a list of data saved in a memory of said processing means, related to said optimal orientation (21 ) from previous processing cycles for elements (2) of the same type.

4. Method according to one of the preceding claims, characterized in that said step e. of tightening and rotating said element (2) is preceded by the step of temporarily releasing said element (2) from gripping and/or guiding members (32) of said apparatus (1 ), to make said element (2) free to rotate around said longitudinal axis.

5. Method for supplying elongated metal elements, in particular metal bars, for example designed for a bending cycle, comprising the steps of:

i. inserting a said elongated metal element (2) into a drive group (3) along a supply direction

(A);

ii. detecting an actual orientation (22) of said element (2) itself with respect to a respective longitudinal axis coinciding with said supply direction (A), stationary or moving along said supply direction (A), at a detection plane (6) by means of a detection device (4);

iii. supplying said element (2) along said supply direction (A);

iv. detecting a further said actual orientation (22) by means of said detection device (4); v. processing, by means of processing means, any deviation between said actual orientation (22) detected and said further actual orientation (22) detected, indicating a corresponding rotation of said element (2) itself around its longitudinal axis coinciding with said supply direction (A);

vi. stopping the supply of said element (2) along said supply direction (A), tightening by means of an orientation device (5) said element (2) at a respective intercepted section (20) and rotating said element (2) tightened so as to compensate said processed deviation, so as to restore said actual orientation (22) initially detected, or an otherwise desired orientation.

6. Method according to claim 5, characterized in that said step of ii. detecting an actual orientation (22) takes place before carrying out a first bending of said element (2) and that said step of iv. detecting a further said actual orientation (22) takes place before a second bending of said same element (2).

7. Method according to claims 5 or 6, characterized in that said step of rotating said element (2) tightened around said longitudinal axis by an angle such as to compensate said processed deviation is preceded by the step of releasing said element (2) from the engagement of said drive group (3).

8. Apparatus for supplying elongated metal elements, comprising a drive group (3) for supplying a said element (2) along a supply direction (A) coinciding with a respective

29.371 . PC.19_..EN

longitudinal axis of said element (2), a detection device (4) configured to detect an actual orientation (22) of a cross-section (20) of said element (2) inserted longitudinally in said drive group (3) at a detection plane (6), processing means associated with said detection device (4), configured to process any deviation of said actual orientation (22) detected with respect to an optimal orientation (21 ) set or desired for said element (2), an orientation device (5) configured to tight and rotate said element (2) of an angle such as to compensate said processed deviation, so as to orient said element (2) according to said optimal or desired orientation (21 ), characterized in that said processing means are configured for identifying and storing a stable orientation to be considered optimal, among said actual orientations (22) detected, corresponding to an actual orientation (22) of said element (2) which, once achieved, remains substantially unchanged for said element (2) during supply step or in any case it opposes the maximum resistance to a spontaneous rotation of said element (2) around said longitudinal axis or in that said processing means are configured for setting said optimal orientation (21 ), calculating the moment of inertia of said theoretical section (20) with respect to a barycentric axis or calculating the orientation of said element (2) which opposes maximum resistance to rotation of said element (2) about its longitudinal axis during supply step by said drive group (3).

9. Apparatus according to claim 8, characterized in that said detection device (4) is arranged particularly near said supply axis (A).

10. Apparatus according to claim 8 or 9, characterized in that said detection device (4) is an optical device, particularly a video camera, a laser gauge or a profilometer.

1 1. Apparatus according to claim 8 or 9, characterized in that said detection device (4) is a mechanical sensor.

12. Apparatus according to one of claims 8 to 9, characterized in that said orientation device (5) is a clamp member.

13. Apparatus according to one of claims 8 to 12, characterized in that it comprises a bending and/or calendering group and that said orientation device (5) is arranged upstream of said bending group according to said supply direction (A), operable in a suitable phase relationship and in a controlled way before subsequent bending or calendering operations, to rotate said element (2) around its longitudinal axis during a bending or calendering cycle.