METHOD FOR STRAIGHTENING ELONGATED METAL ELEMENTS AND STRAIGHTENER

ASSEMBLY FOR SUCH ELEMENTS

Technical field

[01] The present invention relates to a method for straightening elongated metal elements, in particular metal profiles and rods and similar products, as well as a straightener assembly for these elements.

Background of the invention

[02] Apparatuses for processing elongated metal elements, in particular metal profiles and similar products, which include straightening units are known.

[03] In particular, these units are used, in particular, to straighten rods wound in rolls which, once unwound and straightened, may still have a more or less accentuated residual curvature, which is unsuitable for subsequent processing or for direct use on site.

[04] The aforementioned apparatuses may comprise, for example, straightening units made by means of a plurality of pairs of counter-rotating wheels opposite and staggered which respect to the axis of the wire, through which the rod is fed, so that it is subjected to cyclical actions of yielding by bending, aimed at eliminate its residual curvature.

[05] US patent 1 ,239,175 illustrates, for example, an apparatus for straightening metal wires, comprising a first set of counter-rotating wheels and a second set of counter-rotating wheels, arranged on mutually orthogonal planes.

[06] Patent EP 2961543 illustrates a straightening and drawing device comprising a drawing unit capable of drawing a metal wire along an advance direction, provided with a first main motorized roller, having large size and first contrasting rollers of smaller diameter than the first main roller, arranged idly on a part of the periphery of the first motorized roller. The patent also shows a straightening only unit, independent of the aforementioned drawing unit, arranged along the advance direction, upstream of the drawing unit, and comprising a second main roller, assembled idle and having large size, as well as second contrast rollers with a smaller diameter than the second main roller, arranged idly on a part of the periphery of the second main roller. This unit exerts a plastic deformation action on the wire in transit such as to reduce the internal stresses present in the wire.

[07] KR 100707912 discloses an apparatus for straightening elongated metal elements.

[08] US 6,237,383 illustrates a device for unwinding wires by means of a rotating support.

[09] Patent application US 2,517,309 discloses an apparatus for straightening metal wires along a feeding line.

[10] Patent application DE 2057943 describes a drawing apparatus for continuous elements, such as for example metal wires, for straightening of the same.

[11] However, known solutions do not fully satisfy the needs of the specific sector, in particular with regard to the effectiveness of straightening, the flexibility of use with any type and size of metal wire, as well as the possibility of adjustment and use in case a pair or more metallic wires is fed side by side.

[12] Furthermore, known solutions, in particular those, which work on orthogonal planes, have a complex construction, therefore expensive one.

Disclosure

[13] It is an object of present invention to solve the aforementioned problems by devising a method for straightening elongated metal elements, which enables these elements to be effectively straightened, as well as a straightener assembly for these elements, suitable for implementing this method.

[14] It is another object of the present invention to provide a straightener assembly for elongated metal elements, which is of simple construction and functional conception, provided with safe and reliable use, as well as with a relatively economic cost.

[15] The mentioned objects are achieved, according to the present invention, by the straightening method according to claim 1 and by the straightening assembly for the same elements according to claim 8.

[16] According to a prerogative of the invention it is therefore possible to perform the straightening by arranging along a feeding line for an elongated element a straightener assembly comprising a frame having a first roller and a second roller, which may be rotated respectively around a first axis and a second axis mutually parallel, and spaced so that a passage for the aforesaid element is defined between them on a plane orthogonal to said first axis and to said second axis, the frame being movable according to a rotation motion around a rotation axis parallel to said first and to said second axis, between an angular configuration for inserting the element along the feeding line, where the first roller and the second roller are arranged opposite to the feeding line and the passage defined between the first roller and the second roller is aligned to the feeding line for inserting the element, and at least a configuration and straightening angle, where the first roller and the second roller are both at least partially on the same side with respect to the feeding line, so as to arrange the aforementioned passage along a sinuous path suitable for straightening the element.

[17] The aforementioned sinuous path is preferably aligned with said feeding line, both upstream and downstream of said straightening assembly.

[18] Preferably, said first and said second axes are arranged in an adjustable manner on the aforementioned mobile frame.

[19] According to the invention, the straightener assembly is positioned first in the insertion angular configuration, by operating the frame manually or by means of a motor member in said rotation motion. In this configuration the first wheel and the second wheel do not interfere with the straight path of the element corresponding to the feeding line.

[20] Subsequently, the metal element is thus easily inserted along the feeding line through the straightener assembly.

[21] The element inserted in this manner is engaged, preferably by a drawing assembly associated with the straightener assembly.

[22] Finally, the straightener assembly is positioned in said angular straightening configuration, operating the support frame of the first and the second rollers in the aforementioned rotation motion. The element is then fed along the feeding line, preferably by means of said drawing assembly, so as to operate at the same time its straightening.

[23] Advantageously, the method according to the invention and the straightener assembly that implements it enable a creation of a sinuous path along the feeding direction of the element to be straightened, therefore characterized by a possibly accentuated curvature which is able to ensure an equally accentuated plastic deformation of the material that guarantees an optimal straightening.

[24] Thanks to the provision of the mobile frame, which may be operated preferably by the motor member, it is possible to adjust the amount of deformation imposed on the metal element to identify the most suitable sinuous path, so as to allow the straightening of any type of elongated metal element. Advantageously, the versatility of the straightener assembly may be ensured by the operation of a single motor member.

[25] According to the invention it is possible to obtain an optimal straightening of the element by acting on a single plane containing said sinuous path, in addition to said feeding direction, without the need to use expensive plurality of straightening units in succession, acting on different planes.

[26] Preferably the first roller and the second roller are arranged eccentric with respect to said frame rotation axis, so that the plastic deformation action is even more effective on a wide variety of elements, in terms of size and type. In fact, each type of element, depending on the transverse dimensions, the conformation, the material, as well as the internal tensions, requires a specific straightening action.

[27] Preferably the first axis and the second axis of the first roller and of the second roller, respectively, are arranged at a different distance from the rotation axis of the movable frame.

[28] Preferably the first axis and the second axis of the first roller and of the second roller are not diametrically opposed to the rotation axis of the movable frame.

[29] The assembly according to the invention is able to meet these needs, by diversifying the straightening action with the control, preferably, of a single motor member, which determines the arrangement of the first roller and the second roller in said angular straightening configuration. [30] Preferably at least one of the first roller and the second roller is fixed idle on the frame. In this case, advantageously, if the movable frame is operated by a motor member, the straightener assembly may comprise a single motor member which easily controls the controlled rotation of the frame, thus regulating the straightening efficiency of the straightening members, that is of the first roller and the second roller.

Description of drawings

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

Figure 1 shows a side view of an apparatus for processing elongated metal elements, comprising the assembly according to the invention in an angular insertion configuration; Figure 2 shows a side view of said assembly in an angular straightening configuration; Figures 3 to 6 illustrate a side view of said assembly in different preparatory steps for the extraction of a metal element;

Figures 7 and 8 show respectively a side view of a straightener assembly according to a further embodiment, in different operating steps;

Figures 9 and 10 show respectively a side view of a third embodiment of the assembly according to the invention, in different operating steps.

Best mode

[32] With particular reference to Figures 1 and 2, the reference numeral 1 indicates as a whole an apparatus for processing elongated metal elements 2, in particular profiles and metal rods, comprising a straightener assembly 10.

[33] The straightener assembly 10 is suitable for straightening at least one element 2 fed along a feeding line A according to a feeding direction indicated by a corresponding arrow in Figure 1 , from an inlet section 3 to an outlet section 4 of the apparatus 1. It is also possible to provide for the assembly 10 to be configured to straighten, for example, a pair of elements 2 fed to the apparatus 1 simultaneously. In the following of the present description, reference will be made to a single element 2, meaning however, due to the different features illustrated and/or involved, the possibility of feeding a plurality of elements 2, for example a pair.

[34] The apparatus may comprise, for example, at least one drawing assembly 5, no matter how arranged and produced, for example of the type of clamp, of crawler track, with a larger wheel and smaller contrast wheels, associated with the straightener assembly 10, for example downstream along the feeding line A according to said feeding direction.

[35] The straightener assembly 10 may also be associated with further auxiliary drawing and/or straightening assemblies 6 arranged along the feeding line A downstream and/or upstream of the same assembly (see Figure 1 ) and cooperating with it.

[36] The apparatus may also comprise an inserter assembly 7 arranged at the inlet section 3 and preferably equipped with an inserter device 8 and a replacement device 9, to ensure the correct insertion of the element 2 along the feeding line A and the replacement of the element 2 in case of exhaustion or change of production, for example for processing an element of different transversal size or diameter.

[37] The straightener assembly 10 comprises a movable frame 11 , carrying at least a first roller 12a and a second roller 12b, fixed rotatable around a first axis 13a and a second axis 13b respectively. The first axis 13a and the second axis 13b are arranged parallel and spaced so that a passage between the first roller 12a and the second roller 12b for the element 2 on a plane orthogonal to them is defined.

[38] Preferably the first roller 12a and the second roller 12b are secured idly on the frame 1 1.

Alternatively, it is possible to provide that at least one of the first roller 12a and the second roller 12b is motorized or that both are motorized.

[39] The movable frame 1 1 is operated by a respective motor member 14, according to a rotation motion about a rotation axis 15.

[40] The frame 1 1 holding the first roller 12a and the second roller 12b is therefore movable and preferably positioned continuously on command of the motor member 14 among a wide variety of angular configurations. Alternatively, it is possible to provide that the frame 1 1 may be operated according to a rotation movement in a manual way, for example through the use of a suitably arranged crank member.

[41] Preferably the frame 1 1 may be positioned at least in an angular insertion position, for example which is illustrated in Figure 1 , where the first roller 12a and the second roller 12b are arranged opposite each other with respect to the feeding line A and the passage defined between the first roller 12a and the second roller 12b is such as to enable the free passage of the rod along a substantially rectilinear path, corresponding to the feeding line A, for inserting the element 2, and in an angular straightening configuration, in which the first roller 12a and the second roller 12b are both at least partially on the same side with respect to the feeding line A, so that the aforementioned passage is arranged along a sinuous path capable of straightening the same element 2, as shown for example in Figure 2.

[42] Preferably the first roller 12a and the second roller 12b are arranged eccentrically with their respective axes 13a, 13b with respect to the rotation axis 15 of the frame 11. This circumstance makes it possible to achieve a variety of paths, more or less sinuous, in particular capable of generating an accentuated plastic deformation of the material, which may be modulated at will, therefore suitable for straightening elements 2 of any kind, for the passage path suitable for the element 2 to be straightened. [43] The first roller 12a and the second roller 12b are preferably made of different diameters, so as to be able to define the widest range of sinuous paths for the metal element 2 and, therefore, deformations, in order to be able to identify the most suitable configuration for straightening a variety of elements 2.

[44] The frame 11 may be made, for example, in the form of a disk, for reasons of compact construction. Alternatively, it is possible to provide other embodiments of the same frame 1 1 provided that they are suitable for the purpose.

[45] The rollers 12a and 12b may be in any position because they are not diametrically opposite to the axis 15.

[46] Preferably the frame 1 1 has additional holes prepared for fixing the first wheel 12a and the second wheel 12b, so as to correspondingly expand the possibility of placing them on the frame 11 , adapting the arrangement, therefore also the mutual distance, of the first wheel 12a and of the second wheel 12b to the type of element 2 to be straightened.

[47] Furthermore, the frame 11 may be rotated both clockwise and anticlockwise, so as to be able to impart the desired deformation correspondingly by means of the first wheel 12a or the second wheel 12b, according to the type of element 2 to be straightened.

[48] The method for straightening elongated metal elements is easy to understand from the foregoing description.

[49] In a step of preparation of a new work cycle, the straightener assembly 10 is positioned in the insertion angular configuration, on command of the motor member 14, to enable the insertion of the element 2 along the feeding line A (see Figure 1 ).

[50] The inserted element 2 is then engaged by drawing means, for example by the drawing assembly 5 and/or by the auxiliary assemblies 6.

[51] At this point the straightener assembly 10 is positioned, for example on command of the motor member 14, in the angular straightening configuration, in which the first roller 12a and the second roller 12b are rotated around the rotation axis 15, so that said passage is arranged along a sinuous path suitable for straightening the element 2. This path, resulting in practice from the angular rotation of the frame 1 1 , may be preferably adjusted on the basis of the particular features of the element 2 to be straightened. These features may include the transverse dimension, the surface state, the presence of internal stresses and the mechanical features of the steel used for element 2.

[52] Finally, the element 2 is fed along the feeding line A, through the straightener assembly 10, so that it is subjected to an effective straightening action following the passage through said sinuous path defined by the first roller 12a and the second roller 12b arranged in the straightening angular configuration to finally arrive in a sufficiently malleable state for being able to be arranged with good precision and stably in a rectilinear configuration by the finishing assemblies located further downstream. [53] Therefore the method according to the invention and the straightener assembly, which implements it permit to achieve the aim of effective straightening of elongated metal elements.

[54] According to a further advantageous embodiment of the method it is also possible to carry out the extraction of the element 2, at the end of the production cycle or in the event of its exhaustion.

[55] For this purpose, the portion of element 2 inserted inside the apparatus 1 must be extracted, by moving the same element 2 along the feeding line A in a direction opposite to the supply direction mentioned above.

[56] It should be noted that, following a production cycle, which includes a straightening step, the inserted element 2 is warped, in particular bent, in a corresponding portion, following the passage through the straightener assembly 10 arranged in the angular straightening configuration.

[57] When the element 2 is drawn in the opposite direction to the feeding direction, the warped curve of said portion of the element 2 may easily become further curved due to the generated friction instead of move back, creating a loop, or in any case it tends to oppose a considerable resistance to the extraction of the element 2 along the substantially rectilinear channel, defined by the other members arranged between the straightener assembly 10 and the inlet section 3 along the feeding line A.

[58] In order to enable easy extraction, the frame 1 1 is then driven in rotation, preferably by means of the motor member 14, so that the bending is performed, for example in successive steps, in the opposite direction of said curved portion, so as to straighten it at least roughly, but in such a way as to enable the drawing of the element 2 in the opposite direction of the feeding direction (see Figures 3 to 6).

[59] Alternatively, for example if it is sufficient to move the element 2 back only for a short distance, it is possible to provide that the straightener assembly 10 is movable along the feeding direction A between an advanced position in the feeding direction and a backward position (see Figures 7 and 8).

[60] According to a further embodiment, shown in Figures 9 and 10, the straightener assembly 100, for the remainder completely similar to what has been described above including the different embodiments, comprises a wire guide device 16, for facilitating the guide of the element 2 in the step of insertion of the element 2 which, in particular when it has not yet been subjected to a straightening cycle.

[61] Preferably the wire guide device 16 is arranged downstream of the straightener assembly 100, according to the feeding direction mentioned above.

[62] The wire guide device 16 may for example be made by means of a pair of containment members 17, 18, arranged on opposite sides with respect to the feeding line A. For example, each containment member 17, 18 may shape a jaw. The containment members 17, 18 are alternatively movable between an inactive configuration, separated from the feeding line A (see figure 10), and an active configuration, placed next to the feeding line A, so as to cooperate mutually to define a guide channel for element 2 (see Figure 10). For example, each containment member 17, 18 may be operated rotating, between the inactive, open configuration and the active, closed configuration, such as to contribute to define said guide channel.

[63] The straightener assembly 10 described by way of example may be modified according to the different needs.

[64] In the practical embodiment of the invention, the materials used, as well as the shape and the dimensions, may be modified depending on requirements.

[65] 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.