Method and apparatus for supplying elongated metal elements - Patents.com

Abstract

A method for bending an elongated metal element (specifically, a metal bar) provides for first setting an optimal orientation (21) of a theoretical cross section (20) of the element (2) to be fed relative to its longitudinal axis, and then inserting the element (2) into a drive group (3) along a feed direction (A) that coincides with the longitudinal axis of the element (2). The method further provides for detecting an actual orientation (22) of the element (2) to the longitudinal axis in the cross section (20) by a detection device (4), and processing any deviation of the detected actual orientation (22) of the element (2) relative to the optimal orientation (21) by processing means associated with the detection device (4). An orientation device (5) then operates to orient the element (2) according to the optimal orientation (21), for example, by tightening and rotating the element (2) about the longitudinal axis by an angle to compensate for the processed deviation.

Description

[Technical field]

[0001] The present invention relates to a method and an apparatus for feeding elongated metal elements (particularly bar-like metal profiles and rods) intended for example for a bending or burnishing cycle. [Background technology]

[0002] 2. Description of the Related Art Machines for processing elongated metal elements (in particular bar-shaped metal profiles and similar products) are known which include at least one drive group and at least one bending group.

[0003] 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 and faces relative to the feed direction of the element to be fed.

[0004] On the other hand, a bending group may consist, for example, of a bending head including a central mandrel around which bending pivots can rotate and operate in each bending plane, so that an element fed to the bending head can undergo one or more successive bending operations to produce a moulded part, an open or closed profile bracket and thus a flat or three-dimensional product intended for a building scaffold.

[0005] In the commonly owned EP patent specification 2714296, for example, an apparatus for making two-dimensional and three-dimensional brackets is shown, which comprises guiding means for feeding a metal rod along a feed direction, a first bending group consisting of a first central bending mandrel and a first eccentric bending pivot rotatable about the first central mandrel to bend the metal rod on a work table, and a second bending group including a second central mandrel and a second bending pivot movable around the second central mandrel to bend the metal rod in a bending plane inclined relative to the work table.

[0006] In the production of flat products (particularly brackets, mouldings and polished products) made from metal elements such as bars or rods, there is a challenge to guarantee an acceptable tolerance of the flatness of the finished product. In fact, the element naturally has a tendency to rotate around its own longitudinal axis while it is being fed by the drive and bending groups, and therefore, following this spontaneous rotation, the result of the bending process may deviate from the flatness beyond the tolerance considered acceptable.

[0007] For example, EP 3225322 A1 shows a bending method and a bending device for producing elements which are bent in several dimensions. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] European Patent No. 2714296 [Patent Document 2] European Patent Application Publication No. 3225322 Summary of the Invention [Problem to be solved by the invention]

[0009] The object of the present invention is to solve the aforementioned problems by devising a method and a device for enabling the supply of elongated metal elements intended to be processed to produce moldings such as brackets or generally moldings for building scaffoldings.

[0010] Another object of the present invention is to provide an apparatus for feeding elongated metal elements of simple construction and functional concept resulting in safe and reliable use, as well as relatively low cost.

[0011] The aforementioned object is achieved according to the invention by a method for supplying elongated metal elements according to claims 1 and 5 and by a device for supplying elongated metal elements according to claim 8.

[0012] It is therefore possible, in accordance with the rights of the present invention, to control the supply of the elongated metal elements so as to enable their processing (in particular bending or polishing) in an optimal manner. [Means for solving the problem]

[0013] According to the invention, the method provides for identifying or setting, in a control unit of an apparatus for processing an elongated metal element, an optimum orientation of a theoretical cross-section for the elongated metal element relative to a fixed reference system integral with the apparatus supplying the element itself.

[0014] The aforementioned optimal orientation represents the orientation of the aforementioned theoretical cross section, which corresponds to the minimum movement of the element rotating about its own longitudinal axis when the element is fed by the drive group of the feeding device and, optionally, undergoes a bending operation.

[0015] In fact, when an elongated metal element is inserted and fed by a member (generally the opposing wheels of a drive group), the element itself is subjected to a corresponding frictional force and therefore an opposing thrust action by said member which generates a traction force in the feed direction corresponding to the movement of the drive member. It can be observed that an element pulled along said feed direction is usually subjected to a spontaneous rotation about its own longitudinal axis, which spontaneous rotation can be precisely contrasted with the aforementioned frictional action and therefore with the thrust exerted by the drive member by its contact on the element itself.

[0016] This motion is also influenced by the degree to which the cross-section itself is found to be oriented relative to the drive members themselves. More precisely, when an element is interposed between drive members, it is only possible, moreover empirically or theoretically, to identify a more stable orientation (and therefore an optimal orientation among any other possible orientations of the cross-section of the element).

[0017] In other words, said optimum orientation represents the orientation assumed by the elements engaging between said members of the drive group and corresponds to the maximum resistance to rotation created by contact with said members.

[0018] In practice, generally, for a metal rod in normal use which is provided with ribs around its periphery, and thus for example with longitudinally oriented projections, said optimum orientation is represented by the orientation in which said ribs undergo a reaction on contact with the drive member by a torque reaction to a rotation about the longitudinal axis of the element itself.

[0019] The greater resistance of the element to spontaneous axial rotation, which is favorable for stabilizing and thus optimizing the orientation of the element itself, can be calculated, in particular, by the generation of a resistive torque, the amount of which (in particular, the torque when the driving member has a flat contact shape) is given by the amount of opposing thrust action exerted by the driving member of the element itself, in turn, by multiplying the distance and the amount of action.

[0020] The method therefore provides for inserting a supplied element into a drive group provided with the aforementioned drive members along a supply direction coinciding with the longitudinal axis of the element itself, and detecting by means of a detection device the actual orientation of the inserted element relative to a fixed reference system in the detection plane.

[0021] This detection to determine the actual orientation can be done while the element is stationary or while the element is moving along the feed direction.

[0022] According to the invention, the processing steps are preferably performed in real time by processing means associated with the detection device, the processing means being configured to accurately process possible deviations between the actual orientation detected by the detection device and an optimal orientation (e.g. a set orientation calculated for the element).

[0023] In case said detection device comprises image detection means, the detection of the actual orientation of the element may comprise a step of reconstructing, by said processing means, an instantaneous image of the detected cross section of the element in the detection plane.

[0024] Furthermore, if the detection device includes an image detection means, the step of processing any deviation between the actual orientation and the optimal orientation may include a step of comparing the reconstructed instantaneous image with an image set with respect to the optimal orientation.

[0025] In accordance with the provisions of the present invention, the element is therefore tightened in at least one cross section and released from possible fastenings that may be caused by other members of the apparatus, in order to rotate about its longitudinal axis by an orienting device, such as by an angle to compensate for the deviations detailed above, so as to position the element according to the aforementioned optimal orientation.

[0026] The element is then again clamped by a member of the apparatus (e.g. a drive member) and fed by the drive group, and can be released from the clamping of the orientation device to undergo the calculated processing cycle (e.g. one or more bending operations interrupted by unfolding of the element).

[0027] Advantageously, it is possible to provide that the detection device performs a detection operation for each cross section passing through the detection surface in a further actual orientation, during successive stages of supply of the element itself, at predetermined time intervals or continuously, in order to monitor any deviation in orientation from the detected optimal orientation of that cross section.

[0028] If a deviation is detected according to the steps described above (specifically a deviation exceeding a predefined threshold), the method may call for interrupting the supply of the elements, restoring the optimal orientation.

[0029] By initially setting an optimal orientation in which the movement of the element in rotation about its own axis is minimized, the element can be positioned by the orienting device according to this optimal orientation so as to obtain, after subsequent processing, a finished part that is, for example, within the range of geometric tolerances considered acceptable for a particular production cycle.

[0030] For example, in accordance with certain aspects of the present invention, the optimum orientation of a given provided element may be calculated by the processing means, for example taking into account the moment of inertia (particularly the minimum moment of inertia) of a theoretical cross section of the element relative to the central axis.

[0031] In effect, the method provides for identifying an orientation that provides greater resistance to rotation about the element's own longitudinal axis based on the actual geometry of the element's cross section, either by calculation or performance of past work cycles.

[0032] This greater resistance as mentioned above can be produced by the generation of a torque resisting rotation, which is calculated by the fact that the opposing thrust actions of the drive members are distributed apart and parallel due to the contact of certain irregularities in the contour of the element itself (e.g. ribs).

[0033] The method also provides for detection of the actual orientation of an element in order to identify, calculate, or determine the direction of spontaneous rotation of the element.

[0034] Advantageously, it is also possible to provide for the use of an orientation device to maintain the blocking surface in a clamped state during the bending step of the element being processed, so as to avoid undesired deviations (particularly rotations) from the optimal orientation. These rotations can be caused by irregularities in the contact between the element itself and the operating member (e.g. the bending member), the irregularities being determined by the seemingly random positioning of the irregularities in the contour of the element (e.g. the typical ribs of a metal rod).

[0035] Alternatively, or in addition, before each bending step, an orientation device can be operated to return the element being treated to an optimal orientation, or in any case move it towards the desired orientation.

[0036] In either case, an orientation device can also be used to create three-dimensional elements, to control the rotation of the element being processed, and to restore optimal orientation after undesired rotation of the element being processed.

[0037] Preferably, the step of activating the orienting device is preceded by a step of releasing the element itself, so that the guiding means or traction means, respectively, adapted to engage the element to be fed, allow control of the subsequent rotation for positioning according to an optimal orientation.

[0038] Preferably, the supplied element is, for example, a metal bar or rod of a predefined size.

[0039] According to an alternative solution of the method according to the invention, it is possible to provide that the apparatus according to the invention identifies said optimal orientation of the supplied elements by monitoring subsequent detections of their actual orientations by a kind of self-learning. In practice, the control unit of the apparatus monitors the actual orientations of the metal elements by means of said detection device and identifies a stable or further stable orientation from among said detections.

[0040] For example, the aforementioned stable orientation may correspond to an orientation of a cross-section of an element, which orientation, once achieved, remains substantially unchanged for the element as provided.

[0041] The method preferably also provides for storing, for each element type, this stable orientation identified by successive readings, so that a stable orientation can be set later in a processing cycle using several types of elements.

[0042] Furthermore, the method according to the invention can provide for inserting the elongated element in a drive group provided with a drive member along the feed direction, detecting a first initial actual orientation of the elongated element at rest or in motion along the feed direction, and detecting at least one further actual orientation, for example after a predefined time interval or before or after the first bending operation. Finally, the method provides for processing, by the processing means of the control unit of the device, a possible deviation between the first and the second detection, indicating a corresponding rotation of the element itself along its longitudinal axis coinciding with the aforementioned feed direction. As in the previous case, the element is blocked, clamped and rotated by an orientation device to compensate for this deviation, to restore the initial orientation, or in any case the desired orientation.

[0043] The apparatus for carrying out the method according to the invention therefore comprises a drive group provided with drive members for feeding an element along a feed direction coinciding with the longitudinal axis of the element itself. Due to the provision of the aforementioned processing means of the detection device and the orientation device, the apparatus allows the detection of the actual orientation of the fed element placed in the apparatus and in any case the positioning of the element according to an optimal orientation identified and preset by an operator and an optimal orientation calculated or identified by monitoring the subsequent actual orientation by the detection device.

[0044] In this way it is possible to minimize the natural movements of the elements which result in rotation during the advancement step, while ensuring the production of elements with fully acceptable geometric tolerances.

[0045] Preferably, the detection device is arranged next to the drive group, in which the last-fed element is inserted first.

[0046] Alternatively, a detection device, such as an orientation device, can be freely positioned along the feed axis of the element.

[0047] The detection device can be, for example, an optical device (e.g., a laser gauge or a surface profilometer) or a mechanical device (e.g., a mechanical probe).

[0048] The orienting device is preferably made from a rotatable pin member.

[0049] The provided orienting device can perform both the function of orienting the element at the beginning of the working cycle and the function of rotating the element during the bending cycle, which occurs, for example, in particular between successive bending steps generating a three-dimensional element.

[0050] Details of the invention will become more apparent from the detailed description of a preferred embodiment of an apparatus for supplying elongated metal elements and of a preferred embodiment of a method carried out by said apparatus, shown by way of non-limiting example only in the accompanying drawings, in which: [Brief description of the drawings]

[0051] [Figure 1] 1 shows a front view of an apparatus for feeding metallic elongated elements according to the invention in successive operating steps; [Diagram 2] 1 shows a front view of an apparatus for feeding metallic elongated elements according to the invention in successive operating steps; [Diagram 3] 1 shows a front view of an apparatus for feeding metallic elongated elements according to the invention in successive operating steps; [Figure 4] 1 shows a front view of an apparatus for feeding metallic elongated elements according to the invention in successive operating steps; [Diagram 5] 1 shows a schematic front view of the device in different operational steps; [Figure 6] 1 shows perspective views of the device in different operational steps; [Figure 7] 1 shows a side view of the device in different operational steps; [Figure 8] 1 shows a schematic front view of the device in different operational steps; [Figure 9]1 shows perspective views of the device in different operational steps; [Figure 10] 1 shows a side view of the device in different operational steps; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0052] With particular reference to Figures 1 to 10, the number 1 generally indicates an apparatus for supplying elongated metal elements 2 (specifically metal profiles and metal rods).

[0053] For each of the elements 2 (having a cross section 20) sent, an optimal orientation 21 relative to the longitudinal axis of the element 2 itself can be known or calculated by processing means associated with the apparatus 1 itself, in which longitudinal axis the element itself provides the smallest movement relative to spontaneous rotation about its longitudinal axis.

[0054] For example, this optimum orientation 21 can be calculated based on the moment of inertia of the cross section 20 relative to the centroid axis (in practice, the moment of inertia of the theoretical cross section of element 2 relative to the centroid axis), or in either case, the optimum orientation 21 can represent the orientation in which the element resists maximum resistance to rotation about its own longitudinal axis.

[0055] In the absence of a calculated optimal orientation 21, one may consider a desired orientation or an orientation inferred from the performance of a particular type of element 2. Alternatively, as explained below, a detected initial orientation may serve as the optimal orientation (i.e., the basis for the production cycle).

[0056] The apparatus 1 therefore comprises a drive group 3, a detection device 4 and an orientation device 5 adapted to bring together the elements 2 positioned for subsequent processing according to the aforementioned optimal orientation 21 or in any case to a desired orientation or reference.

[0057] The apparatus preferably further includes cutting and bending groups of known types, which are not shown for the sake of simplicity. In particular, the apparatus may include a burnishing group instead of, or in addition to, the conventional bending group.

[0058] The drive group 3 may comprise, in known manner, at least one pair of counter-rotating wheels 30, 31 facing each other relative to the feed direction A along which the elements 2 are inserted and subsequently fed.

[0059] In particular, each pair of opposing wheels 30, 31 preferably includes a grooved peripheral edge which tangentially defines an insertion channel for the element 2 to be fed and which engages, in a known manner, with the intervening element 2 as such.

[0060] The element 2 is preferably insertable by means of a series of guide members 32 (eg a pair of guide wheels facing each other relative to a normally neutral feed direction A).

[0061] The detection device 4 comprises at least one detection member (e.g. an optical or mechanical detection member) configured to detect the orientation of the element 2 in a detection zone (preferably a detection surface 6). In FIG. 1, for example, the trace of said detection surface 6 is indicated by the number 6.

[0062] In practice, the detection device 4 can be constituted, for example, by an image processing unit, a laser gauge or a video camera associated with a surface shape measuring device, if optical, or by a mechanical probe, which is capable of detecting the orientation of a cross section 20 intersecting the aforementioned detection surface 6 relative to the longitudinal axis of the element 2 in a fixed reference system (e.g. a fixed frame of the apparatus 1, etc.).

[0063] The detection device 4 advantageously is arranged along the series of operating members of the apparatus 1 arranged to interact with the element 2 along the feed direction A so as to detect, in a first processing step, the actual orientation 22 of the detected cross-section 20 (and thus, essentially, the actual orientation 22 of the element 2) when the element 2 is inserted into the drive group 3.

[0064] In fact, it is preferred that the detection device 4 is located as close as possible to the drive group 3 (for example close to the guide member 32) so as to be able to detect the actual orientation 22 adopted by the elements 2 in the mechanism.

[0065] In fact, for example, the detection device 4 can detect the actual orientation 22 of the element 2 in the detection plane 6, in particular by detecting several parts of the cross section 20 of the element 2 that exhibit irregularities relative to a perfect axially symmetric profile (in particular a circle). By observing these irregularities during the feeding of the element 2 along the feeding direction A, it is therefore possible to detect possible directions and numbers of rotation of the fed element 2 around its respective longitudinal axis, which are generally undesired.

[0066] For example, if a metal rod or bar is typically used for the structure, such irregularities may include ribs 2a (specifically oriented vertically) and / or ribs 2b (see specifically Figures 1, 5, 6, 8 and 9).

[0067] In practice, in the case of a rod or bar, the aforementioned optimum orientation 22 is represented by the orientation in which the ribs 2a undergo reaction on contact with the drive members 30, 31 by a torque reaction to a rotation about the longitudinal axis of the element itself.

[0068] In this case, the greater resistance of the element 2 to spontaneous axial rotation, which is favorable for stabilizing and thus optimizing the orientation of the element 2 itself, can be calculated in particular by the generation of a resistance torque, the amount of which is in turn derived from the amount of the opposing thrust action F exerted by the driving members 30, 31 of the element itself, by multiplying the distance d and the thrust action F. In this case, as shown in Figure 5, the optimal orientation 21 corresponds to an orientation of an axial plane containing the ribs 2a inclined by an angle α with respect to a central longitudinal plane P perpendicular to the contact surfaces of the driving members 30, 31.

[0069] The orienting device 5 may be constituted by gripping members (eg clamping members) which are rotationally operable to clamp the elements 2 at their respective cross sections and to operate in a controlled rotation about the longitudinal axis of the elements 2 .

[0070] Thus, the orienting device 5 can for example be constituted by a pair of clamps 50, 51 (preferably suitably shaped clamps) facing each other with respect to the feed direction A and thus with respect to the channel for inserting the drive group 3, the clamps 50, 51 being alternately movable between a released state and a clamped state of the element 2 to be fed. Moreover, the clamps 50, 51 are usefully arranged to operate in a rotational manner, as described above, in a controlled manner.

[0071] The clamps 50, 51 advantageously may include a shaped clamp seat having, for example, a triangular or V-shaped profile.

[0072] 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, the processing means being suitable for calculating possible deviations of the detected actual orientation 22 from an optimal orientation 21 initially set for the particular element 2 to be processed or from a desired orientation, as described below.

[0073] Thus, following the calculation of this possible deviation, the orienting device 5 can be actuated accordingly in a controlled manner to rotate and thus position the elements about their respective longitudinal axes 2 in the appropriate direction according to the set optimal orientation 21. Control of the activation of the orienting device 5 must therefore ensure that the elements 2 are oriented to exhibit only slight movements relative to any spontaneous and uncontrolled rotations.

[0074] The operation of the method for supplying a metallic elongated element and the apparatus for manipulating a metallic elongated element according to the present invention can be readily understood from the foregoing description.

[0075] In a preparation step for a new work cycle, the element 2 can be inserted along the feed direction A into the insertion channel of the drive group 3 .

[0076] For this element 2, the optimum orientation 21 is then set or identified in the control unit of the device 1 and is characteristic of the particular cross section 20 of the element 2 itself.

[0077] The detection device 4 detects the actual orientation 22 of the elements 2 in the detection plane 6 and transmits this data to associated processing means.

[0078] The aforementioned processing means then calculates the possible deviation between the actual orientation 22 and the optimum orientation 21 .

[0079] While the element 2 inserted in the insertion channel of the drive group 3 is stationary, the orienting device 5 can operate to clamp the element 2 itself at each cross section blocked by the clamps 50, 51. In this case, any other gripping, guiding or driving member of the present invention can release the element 2, thereby allowing it to rotate freely.

[0080] Based on the offset pre-calculated by the processing means, the orienting device 5 operates in rotation to position the element 2 according to an optimal orientation 21 .

[0081] At this point, the orienting device 5 can release the element 2, thereby enabling the drive group 3 and any other members involved to engage the element 2 and feed it to a downstream processing group, preferably feeding it to a bending head, possibly a cutting unit, or feeding it to a polishing group in order to create a two-dimensional or three-dimensional product as required.

[0082] In particular, according to an alternative solution, which offers advantages when it is not possible to set an optimum orientation 21 at an initial stage, the method according to the invention can provide for inserting the elongated element 2 in the drive group 3 along the feed direction A and detecting a first actual orientation 22 of the element 2 itself. This first actual orientation 22 can be detected immediately before or immediately after performing the first bending operation of the element 2.

[0083] The method then provides for detecting at least one further actual orientation 22, for example before carrying out a second bending operation of the element 2.

[0084] Finally, the method provides for processing, by processing means, possible deviations between the first and second detections, indicating a corresponding rotation of the element 2 itself along its longitudinal axis, which coincides with the aforementioned feed direction A.

[0085] Similar to the solutions of the previously described method, the element 2 is therefore stopped and tightened by the orientation device 5 and rotated to compensate for this deviation and to restore the initially detected first orientation 22 or otherwise the desired orientation.

[0086] In practical embodiments of the present invention, the materials used as well as the shapes and dimensions may vary according to requirements.

[0087] Where there are signs following technical features referred to in any claim, such signs are entirely included for the purpose of improving the understanding of the claims, and thus the signs should not be considered in any way to limit the scope of each element identified by such signs for illustrative purposes.

Claims

1. A method for supplying an elongated metal element (particularly a metal bar), comprising the steps of: a. setting, in a control unit of the device for feeding elements (2) or of the device for identifying said elements (2) to be fed, an optimal orientation (21) of the theoretical cross-section with respect to the longitudinal axis of each element (2); b. inserting said element (2) into a drive group (3) along a feed direction (A) coinciding with the longitudinal axis of said element (2); c. detecting the actual orientation (22) of the cross section (20) of said element (2) relative to the longitudinal axis of said element (2) by means of a detection device (4) in a detection plane (6); d. Processing any deviation of the detected actual orientation (22) of the element (2) relative to the optimal orientation (21) by processing means associated with the detection device (4); e. clamping and rotating the clamped element (2) around its longitudinal axis by an angle to compensate for the processed deviation so as to orient the element (2) according to the optimal orientation (21) by means of an orientation device (5); f. Step f of releasing said element (2); g. feeding said element (2) along said feeding direction (A) to achieve at least one processing step of each of steps a. to f., said step a of setting said optimal orientation (21) comprises the steps of: providing said elements (2) on said detection surface (6), continuously monitoring said actual orientations (22) of said elements (2), and identifying and storing a stable orientation considered optimal among said detected actual orientations (22) corresponding to said actual orientations (22) of said elements (2), said stable orientation remaining unchanged between one elements during the provision of said elements (2) once achieved, or said elements (2) facing a maximum resistance to spontaneous rotation of said elements (2) around their longitudinal axis; or 4. A method according to claim 3, wherein said step a. of setting said optimum orientation (21) comprises calculating, by said processing means, the moment of inertia of said theoretical cross section relative to its central axis, or calculating, by said drive group (3), said orientation of said element (2) during the feeding step which opposes the maximum resistance to rotation of said element (2) about its longitudinal axis.

2. 2. The method of claim 1, characterized in that the step of setting the optimum orientation (21) by calculating the moment of inertia of the theoretical cross section relative to the central axis provides for calculating a minimum moment of inertia of the theoretical cross section relative to the central axis.

3. 3. A method according to claim 1 or 2, characterized in that said step a) of setting said optimum orientation (21) consists in finding said optimum orientation (21) by said processing means from a list of data stored in a memory of said processing means relating to said optimum orientations (21) from previous processing cycles for said elements (2) of the same type.

4. 4. The method according to claim 1, wherein said step e. of clamping and rotating said element (2) is preceded by a step of temporarily releasing said element (2) from the gripping element and / or the guide member (32) of said device (1) and allowing said element (2) to rotate freely around its longitudinal axis.

5. A method for supplying an elongated metal element (particularly a metal bar), comprising the steps of: i. inserting a metal element (2) into a drive group (3) along a feed direction (A); ii. detecting, in a detection plane (6), the actual orientation (22) of each element (2) itself relative to its longitudinal axis coinciding with said feed direction (A), either stationary or moving along said feed direction (A) by a detection device (4); iii. feeding an element (2) along said feeding direction (A); iv. detecting said further actual orientation (22) by said detection device (4); v. processing by processing means any deviation between said detected actual orientation (22) and said detected further actual orientation (22), which indicates a corresponding rotation of said element (2) itself about its longitudinal axis coinciding with said feed direction (A); vi. stopping the feeding of the element (2) along the feeding direction (A), clamping the element (2) at each cross section (20) by means of an orientation device (5) and rotating the clamped element (2) about its longitudinal axis by an angle to compensate for the processed deviation so as to restore the actual orientation (22) initially detected or otherwise desired orientation; The method includes:

6. 6. The method according to claim 5, characterized in that the step ii of detecting the actual orientation (22) is performed before performing a first bending operation of the element (2) and the step iv of detecting the further actual orientation (22) is performed before performing a second bending operation of the element (2).

7. A method as described in claim 5 or 6, characterized in that the step of rotating the tightened element (2) around its longitudinal axis by an angle to compensate for the processed misalignment is performed prior to the step of releasing the element (2) from engagement with the drive group (3).

8. 1. An apparatus for supplying elongated metal elements, comprising: a drive group (3) for feeding the elements (2) along a feeding direction (A) coinciding with the longitudinal axis of each element (2); a detection device (4) configured to detect an actual orientation (22) of a cross section (20) of the element (2) inserted in the longitudinal direction of the drive group (3) in a detection plane (6); - processing means associated with said detection device (4), configured to process any deviation of said detected actual orientation (22) relative to a set or desired optimal orientation (21) for said element (2); an orientation device (5) for clamping and rotating the element (2) at an angle to compensate for the processed misalignment so as to orient the element (2) according to an optimal or desired orientation (21); the processing means is arranged to identify and store a stable orientation considered optimal among the detected actual orientations (22) corresponding to the actual orientation (22) of the element (2), the stable orientation remaining unchanged between one element during the supply of the element (2) once achieved, or in any case the element (2) opposes a maximum resistance to spontaneous rotation of the element (2) around its longitudinal axis, or said processing means setting said optimum orientation (21); 1. The device according to claim 1, further comprising: a drive group (3) configured to calculate a moment of inertia of a theoretical cross section relative to a central axis, or to calculate, during the feeding step, the orientation of the element (2) that opposes a maximum resistance to rotation of the element (2) about its longitudinal axis.

9. 9. Apparatus according to claim 8, characterized in that the detection device (4) is arranged in particular close to the feed axis (A).

10. 10. Apparatus according to claim 8 or 9, characterized in that the detection device (4) is an optical device, in particular a video camera, a laser gauge or a surface profiler.

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

12. 10. Apparatus according to claim 8 or 9, characterized in that the orienting device (5) is a clamping member.

13. Apparatus according to any one of claims 8 to 12, characterized in that the apparatus comprises a bending group and / or a polishing group, and that the orienting device (5) is arranged upstream of the bending group according to the feed direction (A) and is operable in a suitable phase relationship and in a controlled manner before a subsequent bending or polishing operation, to rotate the element (2) around its longitudinal axis during a bending or polishing cycle.

Images