Bar processing machine and corresponding processing method

Abstract

A bar processing machine is suitable for processing at least one substantially elliptical bar (B), the machine comprising at least two supporting slides (11), at least one of the supporting slides being reciprocatingly movable toward / away from the other along a movable axis (Z), each supporting slide being provided with a processing plane (12), on which at least one bending unit (13) and at least one first bending unit (14) are mounted, the bending unit (13) being suitable for bending at least a longitudinal portion of the bar (B), the first bending unit (14) being provided with a first relative element (17) having a first bending radius (R1), and a first bending element (18) being selectively rotatable about the first relative element (17) so as to bend the bar (B) about it.

Description

Technical Field

[0001] The invention relates to a bar processing machine for bending and / or curving bars or, in general, for approximately oval products, such as rods, curved parts, square parts, etc., with a circular, polygonal or flat cross section.

[0002] By way of example only, the rod processing machine may bend and / or bend rod that is fed in the form of bars or coils, or from a straight bar cutting center. Background Art

[0003] In the fields of building and road construction and not only here, it is known to use bars made of metallic materials, such as iron, steel or other alloys with suitable properties, in order to reinforce concrete structures, thus forming so-called "reinforced concrete" structures.

[0004] These bars, better known as rebar, the steel bars used to reinforce concrete, are often pre-formed, meaning they are pre-bent and curved to a shape and profile that helps strengthen the concrete structure. Bending generally refers to the deformation of a bar through its full or partial longitudinal extension, while bending generally refers to the deformation of a bar through a specific, localized area.

[0005] The bars may have a circular cross section or a circular cross section with ridges and ribbing to facilitate anchoring to the concrete and once adapted to shape they can be connected in a known manner to form the required reinforcement structure.

[0006] To this end, known bar processing machines are suitable for bending and / or curving bars, such as rods, curved parts, and square parts with round, polygonal, or flat cross-sections. For example, international patent application WO 2017 / 033145 A1 filed by the applicant describes a machine of this type.

[0007] WO 2017 / 033145 A1 describes a combined machine for bending and curving rods. The machine comprises a support base configured to support and guide two movable slides along a motion axis, each of which has a processing surface mounted thereon. The processing surface is provided with a bending unit and a bending unit, respectively adapted to bend and curvature at least one portion of one or more rods to be processed.

[0008] Specifically, the bending unit comprises a counter roller and a bending roller. During operation, the rod passes between the two rollers and is bent by one or more parts of the bending roller, with a bending radius corresponding to the radius of the counter roller.

[0009] Although this combined machine is very efficient due to the combined use of a bending unit and a bending unit, it is nevertheless obliged to bend the bars with a single bending radius relative to the radius of the rollers with which the machine is equipped. However, in this particular technical field, it is often necessary to bend the same bar to different radii in order to meet the aforementioned structural requirements, and therefore the machine must in each case be equipped with a bending unit suitable for obtaining such bending radii.

[0010] Because when producing bars with different bending radii, the machine must be constantly reconfigured with bending units of different bending radii, or the bending process must be performed on different machines, and the bars have to be moved from one machine to another, which naturally causes a certain amount of time loss and delay. In addition, the operator usually has to partially process a batch of bars, reconfigure the machine, partially process the entire batch of bars or a part of it again, and so on until the bending process is completed.

[0011] Furthermore, constantly reconfiguring the machine can lead to errors in the assembly of the bending cells, which, if not installed correctly, can cause precision errors in the bending process as well as safety issues for the operators, who are frequently required to intervene in the operation of the machine.

[0012] Therefore, there is a need for an improved bar processing machine that overcomes at least one of the deficiencies of the prior art.

[0013] An object of the present invention is to provide a bar processing machine which is characterized in that bending processes with different bending radii can be performed without the need for constant reconfiguration of the machine.

[0014] Another object of the present invention is to provide a bar processing machine which makes it possible to simplify the execution of different bending operations on the same bar.

[0015] A further object of the present invention is to provide a bar processing machine which is able to reduce the execution times of different bending operations.

[0016] In order to overcome the deficiencies of the prior art, the applicant has conceived, tested and implemented the present technical solution and achieved these and other invention purposes and technical effects. Summary of the Invention

[0017] The invention is described and characterized in the independent claims, while other characteristics of the invention or variants to the main inventive idea are described in the dependent claims.

[0018] The described embodiments of the present invention relate to a bar processing machine.

[0019] The rod processing machine is suitable for processing at least one rod having a substantially oval shape.

[0020] The machine comprises at least two supporting slides, at least one of which is reciprocatingly movable towards / away from the other along a movement axis.

[0021] The supporting slide blocks are each provided with a processing plane, on which at least one bending unit and at least one first bending unit are mounted, and the bending unit is suitable for bending at least one longitudinal portion of the bar.

[0022] The first bending unit is provided with a first opposing element and a first bending element, the first opposing element having a first bending radius, and the first bending element can be selectively rotated around the first opposing element to bend the rod relative to the latter.

[0023] According to one aspect of the present invention, at least one supporting slide includes at least one second bending unit on the processing plane.

[0024] The second bending unit is provided with a second opposing element and a second bending element, and the second bending element can be selectively rotated around the second opposing element to bend the rod relative to the latter.

[0025] The second opposing element has a bending radius that is different from the first bending radius of the first opposing element of the first bending element.

[0026] This has the advantage that, in the same working machine, the same bar can be bent multiple times without having to carry out the bending process on different processing machines, which would require moving the bar, or without having to reassemble the machine with an existing bending unit, which would require assembling a bending unit different from the existing one.

[0027] The invention also relates to a method for processing at least one bar on the processing machine, in particular to a method for performing at least one bending operation on at least one bar and performing two or more bending operations on bars having different bending radii.

[0028] These and other aspects, technical features and technical effects disclosed in the present invention will be better understood with reference to the following description, drawings and appended claims. The accompanying drawings, which are incorporated into and form part of this specification, illustrate some embodiments of the present invention and, together with the description, are intended to describe the principles disclosed in the present invention.

[0029] Each of the aspects and features described in this specification may be implemented independently, where possible. These individual aspects, such as aspects and features described in the accompanying dependent claims, may be the subject of divisional applications.

[0030] It should be understood that any known form or feature discovered during the patent application process shall not be claimed for protection and shall be the subject of a disclaimer. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] These and other technical features of the present invention will become apparent from the following description of some embodiments given as non-limiting examples with reference to the accompanying drawings, in which:

[0032] - Figure 1 is a schematic diagram of a bar processing machine of the present invention;

[0033] - Figure 2-4 Indicates that when bending the bar Figure 1 machines;

[0034] - Figure 5 Indicates that when bending the bar Figure 1 machine.

[0035] To facilitate understanding, the same reference numerals are used to identify the same common elements in the figures where possible. It should be understood that the elements and features of one embodiment are naturally included in other embodiments without further explanation. DETAILED DESCRIPTION

[0036] Reference will now be made in detail to various embodiments of the present invention, one or more examples of which are illustrated in the accompanying drawings. Each embodiment is provided as an illustrative method to illustrate the present invention and is not to be construed as limiting the present invention. For example, features shown or described as part of one embodiment may be applied to or in conjunction with other embodiments to produce yet further embodiments. It is to be understood that the present invention encompasses all such modifications and variations.

[0037] Before describing these embodiments, we must also clarify that this description is not limited in its application to the details of construction and arrangement of components described in the following description using the accompanying drawings. This description can provide other embodiments and can be practiced or implemented in various other ways. It is also important to note that the phraseology and terminology used herein is for illustrative purposes only and is not to be construed as limiting.

[0038] The embodiment described using the drawings relates to a bar processing machine which is indicated as a whole by the reference numeral 10 in the drawings.

[0039] The machine 10 is suitable for processing at least one bar B having a substantially oval shape.

[0040] The bar B may be supplied directly to the machine 10 in the form of bars or coils to be straightened and cut to size, or may come from a straight bar cutting centre.

[0041] Depending on the final product to be obtained, the bars B supplied to the machine 10 may also be of different types, for example of different diameters, materials, surface finishes or others.

[0042] According to some embodiments, the machine 10 comprises at least two supporting slides 11 , at least one of which is movable back and forth along a movement axis Z towards and away from the other, each supporting slide being provided with a machining plane 12 .

[0043] At least one bending unit 13 and at least one first bending unit 14 are installed on the processing plane 12. The bending unit 13 is suitable for bending at least one longitudinal part of the rod. The first bending unit 14 is provided with a first relative element 17 and a first bending element 18. The first relative element 17 has a first bending radius R1.

[0044] The first opposing element 17 is provided with at least one profile having an arched profile characterized by said bending radius R1, such as Figure 2 shown.

[0045] The first bending element 18 can be selectively rotated around the first opposing element 17 to bend the bar B relative thereto.

[0046] According to one aspect of the present invention, at least one supporting slide 11 comprises at least one second bending unit 15 , 16 on the machining plane 12 , wherein the second bending unit 15 , 16 is provided with a second opposing element 19 , 27 and a second bending element 20 , 28 .

[0047] The second opposing element 19, 27 is further provided with at least one profile having an arched profile characterized by said bending radii R2, R3, respectively. Figure 3 and Figure 4 shown.

[0048] The second bending elements 20, 28 are selectively rotatable about the second opposing elements 19, 27 to bend the bar B relative thereto.

[0049] The second opposing elements 19, 27 have bending radii R2, R3, respectively. Figure 3 and Figure 4 Shown - Different from Figure 2 The bending radius R1 of the first opposing element 17 is shown so that the bar B is bent with different bending radii.

[0050] This technical solution allows the operator to pre-equip the machine 10 with opposing elements and bending elements of suitable dimensions for bending the bar B without having to stop during the processing, for example to replace one or more opposing elements or one or more bending elements.

[0051] Furthermore, this technical solution allows performing bending operations with different bending radii on the same bar B in addition to bending operations, for example with a first bending radius R1 and a second bending radius R2, without requiring any movement or removal of the bar B from the machine 10.

[0052] In this and the following description, reference is made to the machining of a single bar B, although it is obvious that the machine 10 can machine a plurality of bars B simultaneously.

[0053] according to Figure 1-5 In the embodiment shown, the support slides 11 are positioned facing each other and can slide on guide rails 21 that are parallel to each other and to the aforementioned axis of movement Z.

[0054] In particular, the supporting slide 11 is movable along a displacement axis Z, which is independent of the specific operation to be performed on the bar B.

[0055] The length of the guide rail 21 in the direction of the moving axis Z can be consistent with the maximum length of the bar B that can be processed by the machine 10 , and the support slide 11 in the housing of the machine 10 can be at one end opposite to the guide rail 21 .

[0056] The machine 10 also comprises a holding device 22 located between the support slides 11 and arranged, during operation, to support and hold the bar B. The central portion of the bar B tends to deform due to its own weight, and the holding device 22 prevents it from unwanted bending.

[0057] As described above, the holding device 22 is configured to hold the bar B on a plane coplanar with the processing plane 12 to prevent the bar B from interfering with the processing plane 12 and being deformed.

[0058] Furthermore, there may be one or more retaining devices 22 compared to the length of the bar B they have to support.

[0059] according to Figure 1 In the illustrated embodiment, the holding device 22 includes at least one central holding device 22, i.e., is configured to hold the center of the bar B. Specifically, the central holding device 22 can be moved and positioned along a first direction orthogonal to the movement axis Z and a second direction coinciding with or parallel to the movement axis Z.

[0060] Preferably, at least three holding devices are provided, wherein the other two lateral holding devices 22 are located on the sides of the central holding device 22 and are preferably arranged symmetrically with respect to the central holding device 22 .

[0061] The advantage is that the movement of the centering device 22 relative to the second direction allows the latter to always support the bar B in its central portion, regardless of the reciprocating distance between the supporting slides 11 .

[0062] The lateral retaining means 22 can only be moved in a direction parallel to the first direction orthogonal to the movement axis Z. If the bar B is very long, that is, when the support slides 11 are separated far apart, for example at one end relative to the guide rail 21 , the lateral retaining means 22 serve as a backup for the central retaining means 22 .

[0063] The holding device 22 is arranged to move parallel to the first direction by means of a sliding guide 23. The center holding device 22 is also arranged to move along the second direction by means of a movable conversion device 24 on a sliding guide 25.

[0064] In operation, if it is necessary to support the bar B with more than one holding device 22 , these holding devices must be aligned in the transverse direction and perpendicular to the axis of movement Z in order to avoid stresses and deformations on the bar B in the transverse direction.

[0065] In some embodiments, the holding device 22 may be of a clamp type, ie, comprise two symmetrical jaws movable relative to a first direction, wherein the jaws define a variable passage gap therebetween for holding and releasing the bar B.

[0066] When the bar B is fed to the machine 10 in a known manner, it can be supported by the holding device 22 and can partially rest on the machining plane 12 of the support slide 11 .

[0067] according to Figure 1 In the illustrated embodiment, each processing plane 12 includes the aforementioned bending unit 13 , a first bending unit 14 and a second bending unit 15 .

[0068] Here and in the remainder of this specification, bending means that a longitudinal portion extending along the length of the bar B or the entire length of the bar B is continuously deformed. During the bending process, the bending unit 13 is driven to deform the bar B while one or both of the support slides 11 are moved along the movement axis Z.

[0069] Here and in the subsequent description of this specification, bending means that the bar B is only locally deformed at the processing position selected by the bending unit, for example Figure 2 During the bending process, while the support slide 11 is stopped, one of the bending units 14, 15 is operated to deform the bar B.

[0070] according to Figure 1-5 In the illustrated embodiment, a third bending unit 16 is further mounted on each processing plane 12 , and the third bending unit is provided with a third relative element 27 and a third bending element 28 , wherein the third bending element 28 can selectively rotate around the third relative element 27 to bend the bar B relative to the latter.

[0071] The third relative element 27 has a different size from the first relative element 17 and the second relative element 19 so as to have a different Figure 2 The first bending radius R1 and Figure 3 The second bending radius R2 is used to bend the bar B into Figure 4 The third bending radius R3.

[0072] In a possible embodiment, not shown, a plurality of bending units can be arranged on the processing plane 12 , even more than three, for example up to seven, and in any case depending on the available space on the processing plane 12 .

[0073] exist Figure 1-5 In the described embodiment, the bending unit 13 and the folding units 14, 15 are installed at preferred positions to facilitate operation and prevent unnecessary interference.

[0074] Specifically, the bending unit 13 can be mounted on the machining plane 12 at an eccentric position, facing a first side 30 of the machining plane 12 perpendicular to the movement axis Z. Although different arrangements are possible, the bending units 14 and 15 can also be mounted on the machining plane 12 at an eccentric position, facing a second side 31 opposite to the first side 30.

[0075] According to a possible technical solution, not shown, the bending units 14 , 15 may be mounted on the support slide 11 at non-mirror positions, ie, at different positions.

[0076] According to a possible technical solution, the bending unit 13 and at least the bending units 14 and 15 can be driven independently or by the same motor.

[0077] According to one aspect of the present invention, Figure 1 As shown, at least one supporting slide 11 provides a single drive arrangement which is arranged to drive at least the bending units 14 , 15 simultaneously or sequentially.

[0078] The drive device comprises a motor member (not shown) provided with a pinion 32 engaging with a toothed top edge 33 .

[0079] The toothed top edge 33 is connected to the first bending unit 14 and allows at least the first bending element 18 to rotate relative to the first opposing element 17 .

[0080] The first bending unit 14 is movably connected to the second bending unit 15, and when Figure 1-5 As shown, the third bending unit 16 is movably connected via gears, as indicated by the “dash-dot line”, thereby forming a synchronous rotation of the bending units 14, 15, and 16.

[0081] According to some embodiments, at least some of the bending units 13 and / or the folding units 14 , 15 may be retracted relative to the processing plane 12 of the respective support slide 11 .

[0082] In particular, the bending unit 13 and the bending units 14, 15 can be moved between a protruding state of the processing plane 12 and a retracted position of the processing plane 12, in which they can act on the rod B, and in the retracted position, they are located below the processing plane 12 and do not interfere with the rod B.

[0083] according to Figure 2 In the first example shown, when the bending unit 14 bends the bar B, the bending unit 14 is in the above-mentioned protruding state, and the second bending unit 15, the third bending unit 16 and the bending unit 13 are located at the above-mentioned retracted positions.

[0084] according to Figure 3 In the second example shown, during the process of bending the bar B by at least one bending unit, the second bending unit 15 is in the above-mentioned protruding state, while the first bending unit 14, the third bending unit 16 and the bending unit 13 are in the above-mentioned retracted positions.

[0085] according to Figure 4 In the third example shown, during the process of at least one bending unit bending the bar B, the third bending unit 16 is in the above-mentioned protruding state, while the first bending unit 14, the second bending unit 15 and the bending unit 13 are located at the above-mentioned retracted positions.

[0086] according to Figure 5 In the fourth example shown, during the process of at least one bending unit bending the bar B, the bending unit 13 is in the above-mentioned protruding state, while the first bending unit 14, the second bending unit 15 and the third bending unit 16 are located at the above-mentioned retracted positions.

[0087] According to some embodiments, Figure 1-5 As shown, the bending unit 13 includes two relative rollers 35 located at relative positions to each other, and at least one relative roller 35 is preferably provided with a positioning device 36, which is arranged to be able to move selectively away from / backwards from the other relative roller 35 so as to adjust the gap between them relative to the bar B.

[0088] The bending unit 13 can be operated in a known manner on the bar B. Figure 5 In the manner shown in the given example, the bending unit 13 also comprises a bending roller 37 which can be positioned at the contrast roller 35 and which is arranged to impart the desired deformation to the bar B.

[0089] The position of the bending roller 37 at the contrast roller 35 determines the curvature of the bar B.

[0090] At least the bending units 14 , 15 are configured to bend at least one end of the bar B, thereby performing head and / or tail bending processing, but processing can also be performed at the middle position of the bar B.

[0091] If one of the bending units 14 , 15 intervenes at an intermediate position of the bar B, it can do so after at least a partial bend has been completed or before the bending process begins.

[0092] According to possible technical solutions, the bending units 14, 15, and 16 can be Figure 1-5 The type shown is provided with pin-type opposing elements 17, 19, 27 and similarly shaped bending elements 18, 20, 28.

[0093] According to a possible variant embodiment, the bending units 14 , 15 , 16 may include hoe-type opposing elements 17 , 19 , 27 .

[0094] A clamping device 26 is also provided on each processing plane 12 of the support slide 11, which is suitable for holding at least a portion of the bar B during the bending process. In this way, during the bending process, the stress on the bar B is limited to the portion of the bar B to be bent.

[0095] The clamping device 26 can move on the sliding guide rail 23 along the first direction on the processing plane 12. The sliding guide rail 23 allows the clamping device 26 to deflect, thereby ensuring that the bar B can be correctly positioned no matter how it is bent or folded.

[0096] The clamping device 26 may also be of the clamp type, as described above with respect to the holding device 22 .

[0097] According to one aspect of the invention, the machine 10 comprises a pulling unit 34 mounted on at least one supporting slide 11 and movable on the machining plane 12 in a direction perpendicular to the movement axis Z. The pulling unit 34 is configured to pull the bar B in the direction of the movement axis Z or to pull at least one supporting slide 11 in the same direction.

[0098] The pulling unit 34 includes pulling rollers 38 arranged in a direction orthogonal to the movement axis Z and defining a variable passage gap therebetween for the rod B to pass through and be pulled.

[0099] In the case where the support slide 11 is not provided with an independent drive device, the support slide 11 can be moved by the traction force applied to the bar B by the traction unit 34. For example, to move the support slide 11 without the traction unit 34, the clamping device 26 of the support slide 11 must clamp the bar B, and the clamping devices 26 of the other support slides 11 must not clamp the bar B. To move the support slide 11 with the traction unit 34, the clamping device 26 of the relevant support slide 11 must not clamp the bar B, and the clamping devices 26 of the other support slides 11 must clamp the bar B.

[0100] according to Figure 1-5 In the embodiment shown, the pulling unit 34 is connected to the clamping device 26 and moves following the movement of the latter.

[0101] Although not shown, the machine 10 may also be connected to a programmable control, management and command unit arranged to govern, manage and control the possible movement elements of the support slide 11 .

[0102] According to possible technical solutions, the moving component supporting the slider 11 can be selected from a worm mechanism, a rack mechanism, a chain mechanism or a similar or equivalent moving mechanism.

[0103] An embodiment of the present invention further relates to a method for processing at least one substantially elliptical bar B using a bar processing machine 10, comprising:

[0104] Performing at least one bending process on the bar B by means of a bending unit 13 for bending at least a longitudinal portion of the bar B;

[0105] The bar B is subjected to at least one initial bending process by a first bending unit 14 , wherein the first bending unit 14 is provided with a first opposing element 17 having a first bending radius R1 and a first bending element 18 selectively rotatable around the first opposing element 17 ;

[0106] The bar B is bent at least once again by the second bending units 15 and 16. The second bending units 15 and 16 are provided with second opposing elements 19 and 27 and second bending elements 20 and 28. The second bending elements 20 and 28 can selectively rotate about the second opposing elements 19 and 27 to bend the bar B thereabouts. The second opposing elements 19 and 27 are provided with a bending radius R1 different from that of the first opposing element 17, thereby bending the bar B to a different bending radius.

[0107] It is obvious that modifications and / or additions of components may be made to the bar processing machine described above without departing from the technical field and scope of the present invention.

[0108] It is also obvious that, although the invention has been described with reference to some specific examples, a person skilled in the art will of course be able to realize many other equivalent forms of rod processing machines having the characteristics recited in the claims and therefore falling within the scope of protection defined by the invention.

Claims

1. A bar processing machine, suitable for processing at least one substantially elliptical bar (B), the machine comprising at least two supporting slides (11), at least one of the supporting slides (11) reciprocatingly moving toward / away from the other along a moving axis (Z), each supporting slide (11) being provided with a processing plane (12), at least one bending unit (13) and at least one first bending unit (14) being mounted on the processing plane (12), the bending unit (13) being suitable for bending at least a longitudinal portion of the bar (B), the first bending unit (14) being provided with a first relative element (17) having a first bending radius (R1), and a first bending element (18) selectively rotating about the first relative element (17) so as to bend the bar (B) about it, characterized in that At least one second bending unit (15, 16) is included on a processing plane (12) of at least one of the slides (11), the second bending unit (15, 16) is provided with a second relative element (19, 27) and a second bending element (20, 28), the second bending element (20, 28) selectively rotates around the second relative element (19, 27) to bend the rod (B) around it, and the second relative element (19, 27) has a bending radius (R2, R3) different from the bending radius (R1) of the first relative element (17); At least one of the support slides (11) provides a single drive device, the drive device being configured to simultaneously or sequentially drive at least the first bending unit (14) and the second bending unit (15, 16), the drive device comprising a motor component, the motor component being provided with a pinion (32) engaged with a toothed top edge (33), the toothed top edge (33) being connected to the first bending unit (14) and allowing at least the first bending element (18) to rotate relative to the first relative element (17), the first bending unit (14) and the second bending unit (15) being movably connected to each other to form a synchronous rotation of the first bending unit (14) and the second bending unit (15); The machine comprises a traction unit (34), which is mounted on at least one of the support slides (11) and moves on the processing plane (12) in a direction perpendicular to the movement axis (Z), and the traction unit (34) is configured to pull the bar (B) in the direction of the movement axis (Z); The traction unit (34) includes traction rollers (38), which are arranged in a direction orthogonal to the movement axis (Z) and define a variable channel gap between them so that the bar (B) can pass through and be tractioned; The traction unit (34) is connected to a clamping device (26), and the clamping device (26) is capable of holding at least a portion of the bar (B) during the bending process. The clamping device (26) moves together with the traction unit (34) on the processing plane (12) in a direction perpendicular to the movement axis (Z) so as to correspond the bar (B) to one of the first bending unit (14) and the second bending unit (15, 16), thereby ensuring that the bending and bending process of the bar (B) can be correctly positioned.

2. The machine according to claim 1, characterized in that At least some of the bending units (13) and / or the folding units (14, 15, 16) can be in a retracted state relative to the processing plane (12) of their respective support slides (11) and can move between a protruding state of the processing plane (12) and a retracted position of the processing plane (12).

3. The machine according to claim 1 or 2, characterized in that The machine comprises holding devices (22) for holding the bar (B), at least one of the holding devices (22) being a center holding device capable of holding the center portion of the bar (B) and being positioned and moved along a first direction perpendicular to the movement axis (Z) and a second direction coinciding with or parallel to the movement axis (Z).

4. The machine according to claim 3, characterized in that The holding device (22) comprises lateral holding devices located on the sides of the central holding device and moving only in a direction orthogonal to the movement axis (Z).

5. A method for processing at least one substantially elliptical bar (B) using the bar processing machine according to any one of claims 1 to 4, comprising: Performing at least one bending process on the bar (B) by the bending unit (13) to bend at least a longitudinal portion of the bar (B); The bar (B) is subjected to at least one bending process by the first bending unit (14), wherein the first bending unit (14) is provided with a first relative element (17) having a first bending radius (R1) and a first bending element (18) selectively rotatable around the first relative element (17); The rod (B) is subjected to at least one re-bending process by the second bending unit (15, 16), the second bending unit (15, 16) is provided with a second relative element (19, 27) and a second bending element (20, 28), the second bending element (19, 27) can selectively rotate around the second relative element (19, 27) so as to bend the rod (B) around it, and the second relative element (19, 27) is provided with a bending radius (R1) different from that of the first relative element (17), so that the rod (B) is bent into different bending radii.

Images