AUTOMATIC BENDING UNIT OF METAL WIRE ELEMENTS OF ELECTRO-WELDED MESHES AND RELATED BENDING PROCESS

Abstract

 The present invention relates to an automatic bending unit (1) for bending end portions of metal wire elements (F) of an electro-welded mesh (R) lying on a work surface (P), comprising a counteracting member (20) comprising a counteracting surface (22) adapted to lock a wire element (F) and define the bend starting point, bending means (30) comprising at least one bending head (31A, 32A) arranged and configured to bend said wire element (F) around said counteracting surface (22), and abutment means (40).
The counteracting member (20) and said bending means (30) are adapted to be moved in a coordinated manner between a non-operative position, wherein said counteracting surface (22) and said bending head (31A, 32A) are arranged in a first side with respect to said work surface (P) and do not interfere with the extension of said wire element (F), and an operative position, wherein said counteract surface (22) and said bending head (31A, 32A) are arranged in a second side with respect to said work surface (P) and interfere with the extension of said wire element (F) to obtain its bending with a plastic deformation. In particular, said abutment means (40) are also movable with respect to the said work surface (P) between a non-operative position and an operative position independently with respect to the said counteracting member (20) and said bending means (30). The present invention also relates to a process for the automatic bending of metal wire elements (F) of electro-welded meshes (R).

Description

TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to an automatic bending unit for bending elongated metal wire elements, such as in particular rods or wires of electro-welded meshes, for example usable in the production of prefabricated reinforced concrete components.

[0002] The present invention also relates to a process for the automatic bending of metal wire elements by means of said automatic bending unit and an apparatus for processing electro-welded meshes incorporating said automatic bending unit.

BACKGROUND OF THE INVENTION

[0003] Modern construction increasingly uses automated prefabrication in order to allow the production of components with very varied dimensional features and shape, suitable for specific uses.

[0004] Prefabricated reinforced concrete components essentially consist of a mixture of concrete, cast in forms or formwork with embedded metal reinforcements having corresponding dimensions and shapes. In fact, the use of prefabricated reinforcement involves speed, ease of execution and containment of construction site costs in the construction phase of a building.

[0005] The greatest complexity of the production system however consists of the automatic shaping of the reinforcement, in particular starting from previously produced flat electro-welded meshes.

[0006] In general, an electro-welded mesh is a substantially flat product, made by crossing in an orderly or non-orderly manner a bundle of longitudinal metal rods with a bundle of transverse metal rods, then welding the joining points with an electric process to form a mesh.

[0007] Bending units are known which are adapted to bend metal wire elements projecting from the mesh link. An example of such a bending unit is described in patent application EP0875308; it uses an oscillating bending device, such as a template or a pair of rocker levers, whose bending ends are adapted to be selectively raised with respect to the lying surface of the mesh according to the type of bend to be made (S or upside down S) and to cooperate in opposition with an overlying device provided at least with one counteracting member, adapted to lock the position of the wire during the bending operation and provide the starting point of the bend, and an abutment member adapted to oppose the natural positioning of the wire after bending.

[0008] Such bending units are adapted to make "stepped" bends only, giving the wire elements an S and/or upside-down S shape. However, in some cases it may be necessary to make 90°, or "L" bends, in which the free peripheral ends of the mesh wires are bent substantially orthogonally to the lying surface of the mesh itself, or multiple 90°, i.e. C-shaped, for example for making metal cages.

[0009] In this case, it is therefore necessary to use a different bending unit, comprising oscillating bending devices and means for advancing the mesh, but without the above counteracting and abutment members, which would be an obstacle for making such bends.

[0010] Consequently, it is necessary to have both bending units, to be used alternatively according to the type of bend to be achieved, with consequent increase in times and costs of construction, management and maintenance, as well as the provision of suitable spaces for housing both machines.

[0011] It would instead be desirable, and it is indeed the task of the present invention, to provide a single bending unit which ensures maximum flexibility of use, allowing both types of bends to be made, namely the "stepped" and the 90°, either simple or multiple.

[0012] Within the scope of the present task, an object of the present invention is to propose an automatic bending unit of wires of electro-welded meshes which is functional and at the same time compact.

[0013] A further object of the present invention is to provide an automatic bending unit of wires or rods of electro-welded meshes which allows the costs of construction, management and maintenance to be reduced.

[0014] Last but not least, another object of the present invention is to provide an automatic bending unit of wires or rods of electro-welded meshes which achieves the above-mentioned task and objects at competitive production costs, so that its use is advantageous also from an economic point of view, and which can be obtained with the usual and known plants, machinery and equipment.

[0015] The above-mentioned task and objects, and others which will become apparent hereinafter, are achieved by an automatic bending unit as defined in claim 1 and by a process for bending a wire element as defined in claim 8; further features are defined in the following dependent claims.

BRIEF DESCRIPTION OF THE FIGURES

[0016] Advantages and features of the invention will be apparent from the following description, made by way of a non-limiting example with reference to the accompanying figures, in which:

• figure 1 shows a top perspective view of an automatic bending unit according to the present invention;
• figure 2A shows a side view of the automatic bending unit of figure 1;
• figures 2B and 2C show a perspective view of two different operating conditions of the automatic bending unit according to the present invention, highlighting the capacity thereof to rotate by 360° on itself;
• figures 3A, 4A, 5A, 6A and 7A show a side view of the steps of the bending process for obtaining a "stepped" bending of head metal wires of a mesh by using an automatic bending unit according to the present invention;
• figures 3B, 4B, 5B, 6B and 7B show a top view of the steps of the bending process for obtaining a "stepped" bending of head metal wires of a mesh by using an automatic bending unit according to the present invention;
• figures 8A, 9A, 10A, 11A and 12A show a side view of the steps of the bending process for obtaining a "stepped" bending of tail metal wires of a mesh by using an automatic bending unit according to the present invention;
• figures 8B, 9B, 10B, 11B and 12B show a top view of the steps of the bending process for obtaining a "stepped" bending of tail metal wires of a mesh by using an automatic bending unit according to the present invention;
• figures 13A, 14A, 15A, 16A and 17A show a side view of the steps of the bending process for obtaining an "L" bending of metal wires of a mesh by using an automatic bending unit according to the present invention;
• figures 13B, 14B, 15B, 16B and 17B show a top view of the steps of the bending process for obtaining an "L" bending of metal wires of a mesh by using an automatic bending unit according to the present invention;
• figure 17C shows a perspective view of a bending unit according to the present invention in a conclusive operating step for obtaining an "L" bend;
• figures 18A and 19A show a side view of the further steps of the bending process for obtaining a "C" bending of metal wires of a mesh by using an automatic bending unit according to the present invention;
• figures 18B and 19B show a top view of the further steps of the bending process for obtaining a "C" bending of metal wires of a mesh by using an automatic bending unit according to the present invention;
• figures 20A, 20B, 20C and 20D show perspective views of the bending unit according to the present invention during a step of the bending process of a metal wire element of an electro-welded mesh, respectively lateral, head, within a window and tail; and
• figure 21 shows a perspective view of an electro-welded mesh in which the end portions of the wire elements constituting it have been bent with different shapes by using an automatic bending unit according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0017] It should be noted that in the following description, the directional terms such as "above, below, vertical, horizontal, lower and upper," as well as any other similar term, should be interpreted with reference to an automatic bending unit when in use, as shown in the accompanying figures.

[0018] With reference to figure 1, an automatic bending unit 1 according to the present invention is shown, adapted to cooperate with elongated wire elements F, such as rods and/or wires, of an electro-welded metal mesh R to obtain the bending thereof according to a desired shape according to the subsequent use of the electro-welded mesh.

[0019] An electro-welded mesh R is a substantially flat product, made by crossing in an orderly or non-orderly manner a first bundle F1 of metal wire elements F, such as wires or rods having a suitable diameter according to requirements, oriented according to a first direction, and a second bundle F2 of metal wire F, such as wires or rods, oriented according to a second direction transverse to said first direction, then electrically welding the junction points to form a mesh.

[0020] Specifically, said bending unit 1 is adapted to bend, by cold plastic deformation, the ends of the wires F, belonging to both bundles F1, F2, which project peripherally with respect to the mesh link, so that at least a portion thereof is arranged on a different plane with respect to the lying surface of the mesh; moreover, if pre-cut windows are provided in the mesh thus obtained, said automatic bending unit 1 is adapted to bend the ends of the wires F of the mesh projecting inside such windows.

[0021] Generally, to be subjected to bending, said mesh is moved, with suitable and conventional pushing or dragging means, along an advancement direction A parallel to its lying surface, which substantially corresponds to the operating surface P of said bending unit 1; in this way, the head and tail ends of the wires F of a first bundle of threads F1 constituting the mesh can therefore be defined.

[0022] As explained in greater detail below, an automatic bending unit 1 acts on each wire element F so that its end portion, initially lying on the work surface P, is arranged on a bending surface M, different from the work P and advantageously orthogonal to it, and preferably extending over the intersection which contains the longitudinal development of such a wire element F, imparting the desired shape to it.

[0023] Specifically, advantageously, said bending unit 1 is adapted to make both "stepped" bends, which allow an end portion of said wire elements F to be imparted an S and/or upside down S shape, and also transverse bends, for example 90°, either simple or multiple, which allow an L shape or a C shape to be imparted, respectively.

[0024] With reference to figure 2A, said bending unit 1 is provided with operating means 100 comprising a counteracting member 20, provided with a counteracting surface 22 adapted to lock the position of the wire element F during the bending operation and provide the starting point of the bend, bending means 30, arranged and configured to bend the wire element F around said counteracting surface 22, and abutment means 40 arranged and configured to oppose the natural positioning of the wire element F, in particular to obtain a "stepped" bend.

[0025] According to an advantageous feature of the invention, and as explained in greater detail below, said operating means 100 can be moved with respect to the work surface P in a coordinated but independent manner, based on the type of bending to be made, at least between a first position, or non-operative position, in which they are arranged in a first side with respect to the work surface P and do not interfere with the longitudinal development of the wire element F, and an operative position, in which they are arranged in a second side with respect to the work surface P and interfere with the wire element F to obtain the desired bending.

[0026] In particular, preferably, in the non-operative position, the operating means 100 are folded down below said work surface P, while in the operative position one or more of said operating means 100 is raised with respect to the work surface P.

[0027] The bending unit 1 is advantageously provided with a support structure 10, on which the operating means 100 and preferably also the actuator means which allow the movement thereof are mounted.

[0028] The support structure 10 further comprises a support surface 5 arranged, in normal use, parallel and essentially coincident with the work surface P, and on which, in use, at least a portion of said mesh R rests. The support surface 5 is provided with a work opening 51 adapted to be positioned at the wire element F to be bent to allow movement of the operating means 100 between the non-operative position and the operative position.

[0029] According to an advantageous feature of the present invention, the support structure 10 can be moved at least along a direction transversal to the advancement direction A of the mesh R, by means of special handling means managed by dedicated driving and control means (not shown).

[0030] In this way, advantageously, the bending unit 1 can perform the desired bend on the ends of the wire elements F belonging to the first bundle F1 of the mesh R, both at the head and at the tail, and also within windows, initially acting on one of them to subsequently move, sliding below the work surface P, at the adjacent one and so on. In this way it is therefore possible to operate with meshes R having links with different pitches, simply by suitably programming the movement of the bending unit 1.

[0031] As shown in figures 2B and 2C, the support structure 10 of the bending unit 1 is also advantageously rotatable on itself by 360° and can also be moved parallel to the advancement direction A of the mesh R, so as to be able to make the desired bends also on the end portions of the wires or rods F belonging to the second bundle F2 of the mesh R, head, tail and within windows. This feature is very advantageous in that it allows a cage to be made starting from a flat electro-welded mesh.

[0032] Returning to figure 2A, the counteracting surface 22 of said counteracting member 20, suitably shaped preferably according to a curvilinear shape, is obtained on a retaining head 21 provided at a first end of a support arm 23 extending along an axis arranged orthogonally to the work surface P, while at the opposite end a sliding foot 24 is obtained.

[0033] Said counteracting member 20 can be moved by first actuator means, such as for example an electric motor, both in a direction orthogonal to the work surface P and in a direction parallel to the work surface P and orthogonal to the sliding direction A of the mesh R, by sliding said foot 24 along two pairs of guides arranged mutually orthogonal.

[0034] The transition between said non-operative position and said operative position advantageously takes place with a compound motion, through the passage through an intermediate non-operative position: in fact, initially said counteracting member 20 is placed in the non-operative position, in which at least the counteracting surface 22 is lowered with respect to the work surface P, and is arranged in the vicinity of the wire element F to be bent, being positioned slightly to the side thereof.

[0035] It is then moved upwards, with a first translational movement along a direction orthogonal to the work surface P, so that at least said counteracting surface 22 is positioned above said work surface P. Subsequently, said member 20 is moved with a second translational movement along a direction parallel to the work surface P and orthogonal to the development direction of the wire element F, so that the retaining head 21 moves exactly above the wire element F; finally, if necessary, the counteracting member 20 is further translated in a direction orthogonal to the work surface P so that the counteracting surface 22 rests against the surface of the wire element F.

[0036] Said bending means 30 instead comprise at least one bending arm 31, and preferably a pair of bending arms 31, 32, essentially formed by corresponding elongated rigid bodies, at the ends whereof suitably shaped respective bending heads 31A, 32A are formed.

[0037] Said bending heads 31A, 32A are advantageously arranged on opposite sides with respect to said abutment member 20 along the development direction of the wire element F to be bent, and preferably arranged equidistant.

[0038] Said bending arms 31, 32 are operatively associated with second actuator means adapted to move them in an alternating manner, that is, either one or the other, and coordinated with said abutment member 20 according to the type of bending to be obtained and the position of the portion of said wire element F which is to be bent, be it head or tail.

[0039] Advantageously, the movement carried out by each of said bending arms 31, 32 for the transition between the non-operative position, concealed with respect to the work surface P, and the operative position, in which at least the corresponding bending head 31A, 32A projects above the work surface P, can take place in different ways, for example by means of a rotation or vertical translation movement, or a combination thereof, along the bending surface M.

[0040] In fact, unlike said counteracting member 20, which acts above the wire element F and consequently must move laterally with respect to the bending surface M to "step over" the same, said bending arms 31, 32 are positioned essentially at the wire element F to be bent, thus being able to move directly on the bending surface M.

[0041] Said abutment means 40 comprise at least a first abutment arm 41, and preferably a pair of abutment arms 41, 42, essentially formed by elongated rigid bodies, at the ends whereof suitably shaped respective abutment heads 41A, 42A are formed.

[0042] Said abutment arms 41, 42 are articulated with a second end to a pin 6 arranged transversely to the development of the wire element F to be bent, and extend from opposite sides thereof so that the respective abutment heads 41A, 42A are preferably equidistant. Furthermore, preferably, said abutment arms 41, 42 have a longitudinal extension such that the respective abutment head 41A, 42A is positioned beyond the bending head 31A, 32A of the bending arm 31, 32 placed on the same side with respect to the abutment member 20.

[0043] Said abutment arms 41, 42 are movable alternately, i.e. either one or the other, by means of a rotation, with opposite directions, around said pin 6 according to the type of bending to be obtained on said wire element F and the position of the portion of said wire element F that is to be bent, be it head or tail.

[0044] In particular, advantageously, said first and said second abutment arm 41, 42 are obtained in a single piece, centrally hinged on said pin 6, so as to perform a "rocker" movement.

[0045] Said pin 6 is preferably mounted integral with said counteracting member 20, so that the translational movement of the latter consequently also drags said abutment arms 41, 42 with it. However, according to an advantageous feature of the present invention, the transition from the lowered position to the raised position with respect to the work surface P of said abutment member 20 and of one of said abutment arms 41, 42 takes place in an independent manner.

[0046] In the transition between said non-operative position and said operative position, said abutment means 40 also perform a compound motion essentially similar to that of said counteracting member 20: initially said arms 41, 42 are placed in the non-operative position, lowered with respect to the work surface P, and in the vicinity of the wire element F to be subjected to bending, positioning itself slightly to the side thereof, similarly to said counteracting member 20.

[0047] Subsequently, one of the two abutment arms 41, 42 is moved, by means of third actuator means, upwards, by means of a rotation around the pin 6, so that the relative abutment head 41A, 42A is positioned above said work surface P. Finally, such an abutment arm is made to translate in a direction parallel to the work surface P but orthogonal to the development direction of the wire element F, so that the abutment head 41A, 42A moves at the wire element F, aligned with said bending surface M.

[0048] With reference to figures 3A - 7A and 3B - 7B, the bending process for obtaining a "stepped" bending of a head wire element F of a mesh R by using an automatic bending unit 1 according to the present invention is described.

[0049] Figures 3A and 3B illustrate the positioning step of the bending unit 1 so that the opening 51 obtained on the support surface 5 is placed at the portion of the wire element F to be bent. In this initial condition, the operating means 100 are in a non-operative position and are arranged below the work surface P.

[0050] In particular, said counteracting member 20 and said abutment means 40 are positioned slightly away from the wire element F to be bent, while said bending means 30 are arranged essentially on the same surface M, orthogonal to the work surface P, and on the intersection whereof said wire element F extends.

[0051] Figures 4A and 4B illustrate the step of movement of the counteracting member 20 and of the abutment means 40 from the non-operative position, lowered with respect to the work surface P, to an intermediate position, raised with respect to the same surface P but non-operating.

[0052] The transition from the non-operative position to the intermediate position occurs by moving the counteracting member 20 with the first actuator means in a direction orthogonal to the work surface P, as indicated by the arrow B of figure 4A, thanks to the sliding of the foot 24 in the corresponding guiding track, so that the counteracting surface 22 is positioned above the work surface P; at the same time, also said abutment means 40, mounted integral with the counteracting member 20 by means of the pin 6, perform a concordant translation. Furthermore, by means of third actuator means, said abutment means 40 perform a rotation around the pin 6, indicated by the arrow C of figure 4A, which allows the first abutment head 41A to be positioned above the work surface P.

[0053] Figures 5A and 5B show the transition of said counteracting member 20 and said abutment means 40 from the intermediate position previously reached to the operative position; this takes place by means of a translation along a direction parallel to the work surface P but transversal with respect to the development of the wire element F, as indicated by the arrow D of figure 5B, so as to bring said counteracting surface 22 and said first abutment head 41 at the bending surface M.

[0054] As shown in figures 6A and 6B, if necessary, said counteracting member 20 can translate orthogonally to the work surface P, as shown by the arrow E of figure 6A, so that said counteracting surface 22 comes into contact with the upper surface of the wire element F.

[0055] Now that all the operating means 100 are arranged along the bending surface M, it is possible to carry out the "stepped" bending on said wire element F: as visible in figures 7A and 7B, the second actuator means move said first bending arm 31 so that the relative bending head 31A switches from the non-operative position to the operative position. During this movement, the bending head 31A interferes with the extension of said wire element F and causes the bending thereof, along said surface M, against said counteracting surface 22, which locks the position of the wire element F determining the start of the bend; said first abutment head 41A, arranged beyond said bending head 31A in the movement direction A of the mesh R, opposes the natural repositioning of the wire element F.

[0056] Once the bending process of a first wire element F of the mesh R is completed, said counteracting member 20, bending means 30 and abutment means 40 are moved with respect to the work surface P with a backward movement from the operative position to the non-operative position, retracting concealed under the work surface P and advantageously allowing the bending unit 1 to be able to be moved at the adjacent wire element F, where the bending process illustrated above can be carried out again.

[0057] Hereinafter, in order not to weigh down the drawings, only the component elements of the bending unit 1 which operate in the illustrated step have been indicated with their respective reference numerals.

[0058] With reference to figures 8A - 12A and 8B - 12B, the steps of the bending process for obtaining a "stepped" bending of a tail wire element F of a mesh R by using an automatic bending unit 1 according to the present invention are shown. The process is essentially similar but specular with respect to that illustrated above for bending a head wire, said second bending arm 32 and said second abutment arm 42 being moved.

[0059] With reference to figures 13A - 17A and 13B - 17B, the steps of the bending process for obtaining an "L" bending of a head wire element F of a mesh R by using an automatic bending unit 1 according to the present invention are shown.

[0060] Figures 13A and 13B show the positioning of the bending unit 1 so that the opening 51 obtained on the support surface 5 is placed at the portion of the wire element F to be bent. In this initial condition, the operating means 100 are in a non-operative position and are arranged below the work surface P.

[0061] The abutment member 20 is then moved from the non-operative position to the intermediate position, with a translation orthogonal to the work surface P indicated by the arrow H of figure 14A; subsequently, with a translation parallel to the work surface P and transversal to the longitudinal extension of the wire element F in the direction indicated by the arrow I of figure 15B, the abutment member 20 is positioned so that the counteracting surface 22 is arranged on the bending surface M. Finally, if necessary, the abutment member 20 is moved downwards, in a direction orthogonal to the work surface P and indicated by the arrow L of figure 16A so that said abutment surface 22 comes into contact with the upper surface of the wire element F, thus reaching the operative position.

[0062] Finally, one of said bending arms 31, 32 is operated by the respective second actuator means to switch from the non-operative position to the operative position, with a movement along the bending surface M, as indicated by the arrow N of figure 17A.

[0063] In order to obtain the "L" bend, the abutment means 40 are not necessary, and therefore remain in the non-operative position. Therefore, the actuation of one of the two bending arms 31, 32 entails a bending of the wire element F against said abutment surface 22 on the bending surface M, which entails a 90° deviation from the work surface P.

[0064] Figure 17C shows a perspective view of the final step of the "L" bending process of projecting portions of wire elements F of a mesh R.

[0065] If one wishes to obtain a "C" bend, one proceeds from the final step of forming an "L" bend and the mesh R is moved along the advancement direction A, lifting the abutment member 20 beforehand or at the same time in the direction indicated by the arrow O of figure 18A, and making it translate laterally in the direction indicated by the arrow Q of figure 18B.

[0066] Subsequently, the counteracting element 20 is repositioned over the wire element F to be bent with a translation in the direction indicated by the arrow U of figure 19B and lowered again as indicated by the arrow S of figure 19A, so that the counteracting surface 22 contacts the upper surface of the wire element F. One of said bending arms 31, 32 is then operated, making it switch from the non-operative position to the operative position with a movement indicated by the arrow T of figure 19A; in this way, a further 90° bend is obtained which, added to the previous 90° bend, produces the desired "C" bend.

[0067] Clearly, a bending process for obtaining "stepped" or "L" or "C" bends can be carried out by the automatic bending unit 1 on all or some of the wires F projecting from the links of the mesh R, be they head, tail, lateral or within pre-cut windows, as shown in figures 20A - 20D, until, for example, the mesh R shown in figure 21 is obtained.

[0068] In summary, a process for the automatic bending of metal wire elements F of electro-welded meshes R by means of an automatic bending unit 1 according to the present invention comprises the following steps:

a) arranging an end portion of a first wire element F on a work surface P;

b) moving a counteracting member 20 from a non-operative position to an operative position in order to arrange the counteracting surface 22 above the wire element F;

c) moving the bending means 30 from the non-operative position to the operative position such that one of the two shaped bending heads 31A, 32A bends a portion of said wire element F against said counteracting surface 22.

[0069] In particular, before said step c), a step b') is provided, possibly carried out at the same time as step b), wherein said abutment means 40 are displaced from the non-operative position to the operative position to oppose the natural positioning of said wire element F during said step c) for obtaining a stepped bend.

[0070] In conclusion, from the foregoing it is clear that the present invention allows the objects and advantages initially envisaged to be achieved. In fact, a very compact automatic bending unit 1 has been implemented but which at the same time ensures ample flexibility of use, thus allowing the costs of construction, management and maintenance to be reduced.

[0071] Advantageously, the fact that the bending unit according to the present invention comprises operating means 100 which can be arranged in a non-operative position, in which they are arranged concealed beneath the work surface P, thus preventing them from interfering with the longitudinal development of the wires F of the mesh R, and that the abutment means 40 are movable independently with respect to the bending means 30 and to the abutment member 20, allows both "stepped" bends and L or C bends to be carried out using the same bending unit 1.

[0072] Furthermore, it is clear that the fact of having a pair of abutment arms 41, 42, movable rocker-like so as to allow the alternating use thereof allows bending both head and tail wire elements F of a mesh R, with respect to its advancement direction.

[0073] Finally, thanks to a support structure 10 rotatable on itself by 360°, it is also possible to process wire elements projecting laterally from the links of the mesh R, with respect to the advancement direction of the mesh.

[0074] It should also be observed that, thanks to its ease of movement, said bending unit can easily make bends on wire elements projecting with respect to the links of the mesh R at pre-cut windows previously made thereon.

[0075] Of course, the present invention is susceptible to numerous applications, modifications or variants without departing from the scope of protection as defined by the appended claims. Moreover, the materials and equipment used in implementing the present invention, as well as the shapes and sizes of the single components, may be the most suitable ones depending on the specific needs, without departing from the scope of protection as defined by the appended claims.

Claims

1. Automatic bending unit (1) for bending end portions of metal wire elements (F) of an electro-welded mesh (R) lying on a work surface (P), said unit (1) comprising:

- a counteracting member (20) comprising a counteracting surface (22) adapted to lock a wire element (F) in order to provide the bend starting point,

- bending means (30) comprising at least one bending head (31A, 32A) arranged and configured to bend said wire element (F) around said counteracting surface (22), and

- abutment means (40),

said counteracting member (20) and said bending means (30) being adapted to be moved in a coordinated manner between a non-operative position, wherein said counteracting surface (22) and said bending head (31A, 32A) are arranged in a first side with respect to said work surface (P) and do not interfere with the extension of said wire element (F), and an operative position, wherein said counteract surface (22) and said bending head (31A, 32A) are arranged in a second side with respect to said work surface (P) and interfere with the extension of said wire element (F) to obtain its bending with a plastic deformation,
characterized in that
said abutment means (40) are also movable with respect to the said work surface (P) between a non-operative position and an operative position independently with respect to the said counteracting member (20) and said bending means (30).

2. Unit (1) according to claim 1, wherein said counteracting member (20) is adapted to be moved between said non-operative position and said operative position by means of first actuator means through at least a first translational movement along a direction essentially orthogonal to said work surface (P) and a second translational movement along a direction parallel to said work surface (P).

3. Unit (1) according to claim 1 or 2, wherein said bending means (30) comprise a pair of bending arms (31, 32), each provided with a bending head (31A, 32A), said bending arms (31, 32) being arranged on opposite sides with respect to said counteracting member (20) along the extension of said wire element (F) and being adapted to be alternately moved between the non-operative position and the operative position by means of second actuator means.

4. Unit (1) according to claim 1, wherein said abutment means (40) comprise a first and a second abutment arm (41, 42) each provided at an end with an abutment head (41A, 42A), said first and second abutment arm (41, 42) being arranged on opposite sides with respect to said counteracting member (20) along the extending direction of said wire element (F) and being adapted to be alternately moved between the non-operative position and the operative by means of third actuator means.

5. Unit (1) according to claim 4, wherein said first and second abutment arm (41, 42) are formed in a single body, centrally articulated around a pin (6) extending orthogonally with respect to the longitudinal extension of said wire element (F), the displacing movement between said non-operative position and said operative position comprising a rotation about said pin (6).

6. Unit (1) according to claim 5, wherein said abutment means (40) are associated with said counteracting member (20) through said pin (6).

7. Unit (1) according to any one of the previous claims, further comprising a support structure (10) whereon said counteracting member (20), said bending means (30) and said abutment means (40) are mounted, said support structure (10) being movable at least along a direction orthogonal to the extension of said wire element (F).

8. Process for the automatic bending of metal wire elements (F) of electro-welded meshes (R) by means of an automatic bending unit (1) according to claim 1, comprising the following steps:

a) arranging an end portion of a first wire element (F) on a work surface (P);

b) moving said counteracting member (20) from said non-operative position to said operative position in order to arrange said counteracting surface (22) above said wire element (F);

c) moving said bending means (30) from said non-operative position to said operative position such that a bending head (31A) bends a portion of said wire element (F) against said counteracting surface (22);

characterized in that
before said step c), a step b') is provided wherein said abutment means (40) are displaced from said non-operative position to said operative position to oppose the natural positioning of said wire element (F) during said step c) for obtaining a stepped bend.

9. Process according to claim 8, wherein said step b') is performed simultaneously with said step b).

10. Apparatus for processing electro-welded meshes comprising an automatic bending unit (1) according to claim 1.

Drawing