Process and plant for the production of reinforcement bars for window / door frame profiled elements

Abstract

The process comprises the following phases: supplying at least one first bar (2) and at least one second bar (3) made of at least one metallic material and extending along relevant longitudinal directions, each provided, at the respective ends, with a first ending surface (4) and with a second ending surface (5); cutting the first bar (2) to obtain at least one reinforcement bar insertable into a relevant window / door frame profiled element and a residual bar (7) provided with the second ending surface (5); positioning the second bar (3) aligned with residual bar (7) with the first ending surface (4) of the second bar (3) facing the second ending surface (5) of the residual bar (7); joining by means of resistance butt welding of said second bar (3) and of said residual bar (7) carried out by means of the flow of current through the ending surfaces (4, 5) facing each other; wherein, prior to the phase of joining, the process comprises at least one phase of machining at least one of the ending surfaces (4, 5) carried out by removal of metallic material to obtain at least one machined surface (16a, 16b) and at least one protruding portion (18), partly defining the ending surface (4, 5) and protruding from the machined surface (16a, 16b) and wherein the phase of joining is carried out by means of the flow of current through the protruding portion (18).

Description

[0001] PROCESS AND PLANT FOR THE PRODUCTION OF REINFORCEMENT BARS FOR WINDOW / DOOR FRAME PROFILED ELEMENTS

[0002] Technical Field

[0003] The present invention relates to a process and a plant for the production of reinforcement bars for window / door frame profiled elements.

[0004] Background Art

[0005] In the window / door frame sector, it is common practice to use bars to reinforce plastic window / door frame profiled elements. The reinforcement bars are generally made of metallic material, such as steel or other alloys, and are fitted into the internal cavity of the profiled elements in order to give the final window / door frame greater strength and robustness. The reinforcement bars also serve as supports for the additional mechanical parts necessary for the operation of the window / door frame, such as hinges, handles, locking systems, etc.

[0006] The known production processes and related plants involve cutting metallic bars depending on the length of the profiled element to be reinforced in order to obtain the corresponding reinforcement bar. In particular, metallic bars can be obtained, e.g., by extruding molten metallic material or by bending metallic sheets.

[0007] The metallic bars are generally long, e.g. 6-6.5 meters, and can be cut several times to obtain as many reinforcement bars.

[0008] The reinforcement bars can be inserted directly into the relevant profiled element at the end of each cutting operation, or stored together and installed at a later stage.

[0009] As already mentioned, the original metallic bars are approximately 6-6.5 meters long, and cutting operations inevitably result in the formation of residual end portions that are too short to be used as reinforcement bars.

[0010] These residual bars are therefore discarded and a new metallic bar is cut.

[0011] After machining the first bar, the remaining residual bar must therefore be removed from the production line to make room for a second bar.

[0012] This operation not only interrupts production operations and consequently lengthens the relevant timeline, but also results in the formation of a large amount of waste products, which has significant consequences on the production costs of the reinforcement bars.

[0013] The discarded residual bars are in fact sent for disposal, thus reducing the amount of material that can actually be used. Furthermore, this drawback requires the purchase of an excess number of metallic bars in order to ensure the production of the required number of reinforcement bars.

[0014] For these reasons, methods are known involving the recovery of the residual bar by joining the residual bar itself to a subsequent bar to obtain a recovered bar, which is then subjected to cutting operations.

[0015] For example, document WO2023126746A1 describes a method for recovering residual bars through a resistance butt welding operation of the residual bar to a second bar, carried out through the flow of an electric current through the ending surfaces of the bars themselves facing each other.

[0016] However, the known methods are susceptible to improvement.

[0017] In fact, the reinforcement bars for window / door frames, being intended for placement inside the profiled elements, do not require special finishes and therefore, even the metallic bars from which they are derived are cut roughly from their precursors. As a result, the ending surfaces of these bars are often irregular. In addition, the inevitable oxidation process of the ending surfaces also alters their surface structure and contributes to increasing their irregularity.

[0018] This can lead to difficulties in joining the residual bar to the second bar, making the joint insufficiently strong, or it can require an excessive expenditure of energy / resources and long machining times in order to ensure an effective joining, thus negating the savings achievable from the recovery of the residual bars.

[0019] Still with reference to the method described in WO2023126746A1, the resistance welding operation described therein, although rapid and effective in avoiding the formation of excessive weld bead, requires the use of high-intensity electric current. In fact, the presence of metallic oxide on the ending surfaces, which is generally less conductive than the corresponding pure metal, does not allow for effective flow of current as would be the case with pure metal.

[0020] This is even more evident in the case of metallic bars with large cross-sections.

[0021] Description of the Invention

[0022] The main aim of the present invention is to devise a process and a plant for the production of reinforcement bars for window / door frame profiled elements that allow ensuring effective joining of the bars and avoiding excessive expenditure of resources.

[0023] A further object of the present invention is to devise a process and a plant for the production of reinforcement bars for window / door frame profiled elements that allow the production and management costs of the production plant to be reduced.

[0024] Another object of the present invention is to devise a process and a plant for the production of reinforcement bars for window / door frame profiled elements that allow the aforementioned drawbacks of the prior art to be overcome within the scope of a simple, rational, easy and effective to use as well as affordable solution.

[0025] The aforementioned objects are achieved by the present process for the production of reinforcement bars for window / door frame profiled elements having the characteristics of claim 1.

[0026] The aforementioned objects are further achieved by the present plant for the production of reinforcement bars for window / door frame profiled elements having the characteristics of claim Brief Description of the Drawings

[0027] Other characteristics and advantages of the present invention will become more apparent from the description of a preferred, but not exclusive, embodiment of a process and a plant for the production of reinforcement bars for window / door frame profiled elements, illustrated by way of an indicative, yet non-limiting example in the attached drawings, in which:

[0028] Figure 1 is an axonometric view of a plant for the production of reinforcement bars according to the invention;

[0029] Figure 2 is an axonometric view of a machine provided with removal means and joining means according to the invention;

[0030] Figures 3-9 are schematic representations of the phases of the process for the production of reinforcement bars according to the invention;

[0031] Figures 10 and 11 are schematic representations of the bars obtainable as a result of the machining phase, in accordance with two different embodiments;

[0032] Figures 11-16 are detailed views of the removal means according to the invention.

[0033] Embodiments of the Invention

[0034] The process for the production of reinforcement bars for window / door frame profiled elements first comprises a phase of supplying at least one first bar 2 and at least one second bar 3 made of at least one metallic material.

[0035] The bars 2, 3 are elongated bodies made, e.g., of iron, steel or other alloys and can be obtained, e.g., by extruding such molten metallic material or by bending metallic sheets.

[0036] In the embodiment shown in the figures, the bars 2, 3 are hollow and have a rectangular crosssection. It cannot, however, be ruled out that the bars 2, 3 may have a different cross-section, e.g., “U”-shaped, “L”-shaped or be of the plate-shaped type. It cannot also be ruled out that the bars 2, 3 may be solid, i.e., not hollow.

[0037] The bars 2 and 3 extend along their relevant longitudinal directions and each is provided with a first ending surface 4 and with a second ending surface 5 substantially perpendicular to the relevant longitudinal direction.

[0038] As is easily understandable, the process is applicable to an indefinite number of bars. However, for the sake of simplicity, the rest of this disclosure will exclusively refer to a first bar 2 and a second bar 3.

[0039] The process comprises a phase of cutting the first bar 2 to obtain at least one reinforcement bar insertable into a relevant window / door frame profiled element and a residual bar 7 provided with the second ending surface 5.

[0040] Depending on the length of the reinforcement bars to be obtained, the first bar 2 can be cut several times to obtain as many reinforcement bars.

[0041] The process therefore comprises repeating the phase of cutting the first bar 2 depending on the length of the desired reinforcement bars.

[0042] The residual bar 7 corresponds to the end stretch of the first bar 2, resulting from the cutting operations, and which is too short to be used as a reinforcement bar.

[0043] In this regard, it should be noted that the cutting phase is carried out by the movement of the bar 2, 3, 10 along a direction of forward movement D, substantially parallel to the longitudinal direction depending on the desired length of the reinforcement bars, so as to position the bar itself where a cutting device is located.

[0044] The process then involves a phase of positioning the second bar 3 aligned with the residual bar 7 with respect to the respective longitudinal directions, with the first ending surface 4 of the second bar 3 facing the second ending surface 5 of the residual bar 7.

[0045] The positioning phase is then carried out by the movement of the second bar 3 along the direction of forward movement D so as to align it with the residual bar 7.

[0046] The process then comprises a phase of joining the second bar 3 to the residual bar 7 carried out by means of resistance butt welding of the second bar 3 and of the residual bar 7 by means of the flow of current through the ending surfaces 4, 5 facing each other.

[0047] The phase of joining will be described in greater detail later in this disclosure.

[0048] Advantageously, the process then comprises repeating the cutting, positioning and welding phases for the recovered bar 10.

[0049] The recovered bar 10 is then subjected to the cutting phase again to produce new reinforcement bars and any new residual bar 7 is welded again to a subsequent bar.

[0050] According to the invention, prior to the phase of joining, the process comprises at least one phase of machining at least one of the ending surfaces 4, 5 carried out by removal of metallic material to obtain at least one machined surface 16a, 16b and at least one protruding portion 18, partly defining the ending surface 4, 5 and protruding from the machined surface 16a, 16b.

[0051] The phase of machining has the function of removing a layer of metallic material from part of the ending surface 4, 5 in order to define a protruding portion 18.

[0052] The phase of joining is then carried out by means of the flow of current through the protruding portion 18.

[0053] In detail, in the phase of joining, the protruding portion 18 is placed in contact with the ending surface 4, 5 of the other bar 3, 7 where a substantially point-like contact area is located.

[0054] The flow of current through an ending surface 4, 5 of substantially point-like extension allows the electric current to be concentrated where actually desired and the electrical power made available by the system to be used efficiently to weld the bars 3, 7, even under conditions of rather low current intensity. At the point of contact between the bars 3, 7, the metal can easily achieve high temperatures, close to its melting point, allowing intimate contact and mixing between the metallic material of the two bars 3, 7, making the welding area limited to the small contact area but very resistant.

[0055] Usefully, the phase of machining is carried out by means of a milling tool 13 movable along a reference plane P substantially parallel to the ending surfaces 4, 5.

[0056] The reference plane P is an ideal plane placed between the bars 3, 7, once these have been arranged with their ending surfaces 4, 5 facing each other.

[0057] The milling tool 13 develops longitudinally along an axis of development A and can rotate around itself around the axis of development A.

[0058] The milling tool 13 develops longitudinally within the reference plane P.

[0059] In other words, the milling tool 13 is of the elongated type and its axis of development A lies within the reference plane P.

[0060] In detail, the milling tool 13 is of the end mill type.

[0061] The machining phase is carried out through the movement of the milling tool 13 along at least one substantially vertical direction of work Wl, W2 and the milling tool 13 is arranged transversely with respect to the direction of work Wl, W2.

[0062] The direction of work Wl, W2 is coplanar with the axis of development A. In other words, the direction of work Wl, W2 also lies within the reference plane P.

[0063] In other words, the milling tool 13 is moved upward or downward and the relevant axis of development A is arranged not vertically. During this movement, the milling tool 13 is placed in contact with the ending surface 4, 5 to determine the removal of the metallic material.

[0064] In accordance with a preferred embodiment, the phase of machining is also carried out under dry conditions.

[0065] Advantageously, the phase of machining comprises at least one step of milling, carried out by the movement along a substantially vertical direction of work Wl, W2.

[0066] The step of milling is carried out so as to contact the ending surface 4, 5 only on a part of its surface extension. In this way, one part of the bar 3, 7 is machined by removing the metallic material while the remaining part is left unchanged, thus defining the protruding portion 18.

[0067] In actual facts, the step of milling is carried out by the movement of the milling tool 13 along the direction of work Wl, W2 until a predefined height is achieved.

[0068] Usefully, the milling tool 13 is inclined with respect to a horizontal plane by a predefined angle of work a.

[0069] Specifically, with reference to the preferred embodiment wherein the bars 2, 3 are hollow and have a rectangular cross-section, the use of a milling tool 13 arranged inclined with respect to a horizontal plane allows facilitating the movement thereof along the direction of work Wl, W2 and optimizing the machining of the bars themselves. In fact, when moving along the direction of work Wl, W2, the inclined milling tool 13 abuts against the bar 3, 7 at one edge, which offers less resistance to milling than a flat face of the bar itself. This not only simplifies the milling operation but also prevents possible deformation of the bar. But that’s not all. The inclined milling tool 13 allows, if desired, the ending surfaces 4, 5 to be machined so as to leave two protruding portions 18 at two opposite edges of the rectangular section of the bars 2, 3 (Figure 10), or an individual protruding portion 18 at one edge of the rectangular section of the bars 2, 3 (Figure 11). This improves the strength of the weld because the edges of the bars 2, 3 are stronger points and can better withstand stress than the sides of the rectangular section of the bars 2, 3.

[0070] Specifically, the axis of development A is inclined with respect to the horizon by a predefined angle of work a.

[0071] Usefully, the angle of work a is of between 5° and 70°. Preferably, the angle of work a is of between 10° and 35°, and even more preferably it is equal to 20°.

[0072] The phase of machining usefully comprises a step of first milling and at least a step of second milling to obtain at least a first machined surface 16a, at least a second machined surface 16b, and a pair of protruding portions 18 opposite each other and placed between the first machined surface 16a and the second machined surface 16b.

[0073] In this way, it is possible to define protruding portions 18 of significantly reduced dimensions so as to concentrate the electric current as much as possible.

[0074] In detail, in the case of bars of the hollow type, one protruding portion 18 is made on one side and the other is made on the opposite side. Furthermore, in accordance with the preferred embodiment, wherein the milling tool 13 is inclined, the protruding portions 18 are misaligned with each other (Figure 10).

[0075] Specifically, the step of first milling is carried out by the movement of the milling tool 13 along a first direction of work Wl, and the step of second milling is carried out by the movement of the milling tool 13 along a second direction of work W2 being directed opposite the first direction of work W 1.

[0076] As shown in Figures 4 and 5 by way of example, the step of first milling is carried out by the movement of the milling tool 13 from top to bottom until it achieves a first predefined height. Subsequently, the step of second milling is carried out by the movement of the milling tool 13 from bottom to top until it achieves a second predefined height (Figure 6).

[0077] It cannot, however, be ruled out that the phase of machining may comprise an individual step of milling, in which case the protruding portion 18 is defined at an edge of the bar 3, 7 (Figure 11).

[0078] It cannot also be ruled out that the phase of machining may comprise more than two steps of milling so to obtain a plurality of protruding portions 18.

[0079] In this regard, it should be noted that in the figures, the extent of material removal is deliberately emphasized in order to make the process and the result obtained more understandable. However, it should be noted that the phase of machining is carried out to a depth of between 0.01 mm and 2 mm, preferably 0.5 mm, with respect to the ending surface 4, 5, and that the protruding portion 18 in turn protrudes by a value of between 0.01 mm and 2 mm, preferably 0.2 mm, with respect to the machined surface 16a, 16b.

[0080] Furthermore, the difference between the first height and the second height is of between 0.01 mm and 2 mm and the protruding portion 18 has a thickness of between 0.01 mm and 2 mm.

[0081] In accordance with the preferred embodiment, the phase of machining is carried out in a specular manner on both bars 3, 7.

[0082] The at least one protruding portion 18 of one of the bars 3, 7 is thus arranged facing the protruding portion 18 of the other bar 3, 7.

[0083] In this way, during welding, the protruding portions 18 are in contact with each other and the flow of current occur through these.

[0084] Furthermore, the phase of machining is conveniently carried out simultaneously on both bars 3, 7.

[0085] Prior to the step of milling, the phase of machining comprises a step of mutual close movement of the bars 3, 7 at a mutual distance less than the diameter of the milling tool 13. At that point, the step of first milling is carried out by the movement of the milling tool 13 along the first direction of work W1 until the first predefined height is achieved. Next, the phase of machining involves a step of mutual away movement of the bars 3, 7, which allows the milling tool 13 to be lowered further without contacting the ending surfaces 4, 5. Subsequently, the step of second milling is carried out by the movement of the milling tool 13 along the second direction of work W2 until the second predefined height is achieved.

[0086] Finally, the phase of machining involves a step of mutual away movement of the bars 3, 7, which allows the milling tool 13 to be moved away, leaving the bars 3, 7 with the protruding portions 18 facing each other.

[0087] At this point, the phase of joining is carried out.

[0088] As previously mentioned, the phase of joining is carried out by means of resistance butt welding by means of the flow of current between the ending surfaces facing each other.

[0089] In the context of this disclosure, the term “butt welding” refers to a type of welding carried out by juxtaposing the ending surfaces 4, 5 of the second bar 3 and of the residual bar 7.

[0090] As is well known to the technicians in the field, resistance butt welding is a method of autogenous pressure welding wherein the metallic material is heated by electrical resistance.

[0091] Usefully, the phase of welding comprises a step of application of electrode assemblies 14, 15 to the second bar 3 and to the residual bar 7 at the respective ending surfaces 4, 5 to determine the flow of current.

[0092] Specifically, the electrode assemblies 14, 15 comprise a first electrode assembly 14 applicable to the residual bar 7 and a second electrode assembly 15 applicable to the second bar 3. The phase of welding also comprises a step of joining the ending surfaces 4, 5 together to determine the formation of an electric arc.

[0093] As is known, an electric arc is an electrical discharge generated between two metallic parts that are close together and connected to an electrical circuit.

[0094] In particular, the step of joining is carried out by moving the second bar 3 and the residual bar 7 close together.

[0095] As the ending surfaces 4 and 5 move close to each other, the electrical circuit tends to close and open repeatedly due to the inevitable mechanical rebounds that are generated. This causes the formation of electric arcs which, in this specific case, are accompanied by high voltages combined with high currents.

[0096] The electric arc is accompanied by the flow of current between the ending surfaces 4, 5, which causes a strong development of heat due to the Joule effect and allows very high temperatures (3,000°C - 4,000°C) to be achieved, leading to the softening and possibly melting of the metallic material in a very short time.

[0097] More specifically, the electric arc causes the formation of a plasma which generates heat.

[0098] Advantageously, the current has an intensity of between 1 KA and 20 KA. Preferably, the current has an intensity of between 3 KA and 10 KA.

[0099] This makes it possible to generate a large amount of energy and to optimize the welding process, speeding up operating times.

[0100] Furthermore, thanks to the previous phase of machining, the current values are always substantially constant, allowing the production process to be standardized in terms of both costs and timing, regardless of the size of the metallic bars.

[0101] Usefully, the step of joining is carried out in such a way as to soften the metallic material.

[0102] The step of joining is carried out for a time of between 0.1” and 20”, preferably of between 1” and 5”, and even more preferably of between 1.5” and 2”.

[0103] In particular, the step of joining is carried out in such a way as to lead to the formation of a sufficient amount of softened metallic material to give the welding area adequate strength but which, however, does not result in the creation of an excessively protruding weld bead.

[0104] This phase of resistance welding allows minimizing the formation of a weld bead that protrudes outward.

[0105] Traditional welding processes, especially those involving the use of a filler material, such as e.g. coated electrode welding, can result in the formation of an abundant weld bead protruding from the welding area.

[0106] In this specific case, the presence of a protruding weld bead could jeopardize the insertion of the reinforcement bar into the relevant window / door frame profiled element. Reinforcement bars are generally provided with a section that fits to size into the cavity defined by the window / door frame profiled element and a protruding weld bead would prevent the insertion thereof.

[0107] Therefore, when traditional welding processes are used, the reinforcement bar would have to undergo further machining to remove part of this weld bead.

[0108] The present process allows therefore further fixing this technical problem and avoiding subsequent machining of the reinforcement bars, thereby further reducing production times.

[0109] More specifically, the step of joining is carried out in such a way that the thickness of the protruding weld bead is less than a predefined minimum value.

[0110] The minimum value is determined based on the dimensions of the internal cavity of the window / door frame profiled element and the dimensions of the reinforcement bar section. It follows that, for example, while in some cases a protruding 2 mm thick weld bead may still allow the reinforcement bar to be inserted into the relevant window / door frame profiled element, in other cases even a protruding 0.5 mm thick weld bead may jeopardize this operation.

[0111] Conveniently, the step of joining is carried out after the phase of application of the electrode assemblies 14, 15.

[0112] In this way, during the step of joining, the second bar 3 and the residual bar 7 are already connected to the electrical circuit and the electric arc is formed as soon as the ending surfaces 4, 5 achieve the minimum necessary distance, thus making welding very fast with the resulting advantages described above.

[0113] Alternative embodiments are however provided wherein the step of joining is carried out prior to the phase of application of the electrode assemblies 14, 15. In other words, the ending surfaces 4, 5 are first joined and placed into contact with each other, after which voltage is applied to the second bar 3 and to the residual bar 7.

[0114] Finally, the phase of welding comprises a step of mutual compression of the ending surfaces 4, 5. During this phase, the softened metallic material of the ending surfaces 4, 5 joins intimately and, as a result of cooling, forms the welding area.

[0115] In particular, during the step of compression, the electrode assemblies 14, 15 are moved away from the second bar 3 and from the residual bar 7, thus interrupting the flow of current and allowing the metallic material to cool down.

[0116] Usefully, the step of compression is carried out for a time of between 0.1” and 10”, preferably of between 0.5” and 3”.

[0117] At the same time, the step of compression is carried out at a pressure of between 0.1 MPa and 15 MPa.

[0118] As a result of the phase of welding, the second bar 3 and the residual bar 7 are joined together through a substantially continuous, resistant weld area which is provided with a small weld bead. Furthermore, this process allows for autogenous welding which, as is known to those skilled in the art, allows metallic materials to be joined without the use of filler material. Filler materials are materials that are heated until they melt and are transferred to the area to be welded. Once solidified, the filler materials serve as a bridge between the welded parts. However, the filler material is not always the same as the metallic parts to be welded and may have different physical and mechanical properties. In addition, welding times using filler materials are generally very long.

[0119] The phase of resistance welding allows for the continuity of the reinforcement bar material to be achieved in a very short time, making the joining area sufficiently strong and robust and avoiding possible differences in the physical-mechanical behavior caused by the use of filler materials.

[0120] Advantageously, the process comprises a phase of cleaning at least one of the ending surfaces 4, 5 carried out by means of removal of metallic material.

[0121] The phase of cleaning allows the ending surfaces 4, 5 to be evened out and leveled, making them substantially smooth and flat, and allows any impurities that could affect the subsequent phase of joining, such as portions of oxidized metallic material, to be removed.

[0122] The phase of cleaning therefore allows making the subsequent phase of joining more effective, ensures a strong bond between the bars 3, 7 and reduces energy consumption.

[0123] The phase of cleaning is carried out prior to the phase of machining. In this regard, it should be noted that Figures 3 to 9 schematically represent a process that comprises the execution of the phase of cleaning (Figure 3). However, it should be noted that this phase of cleaning is not essential to achieving an effective bond between the bars and, therefore, embodiments are provided wherein this phase is not carried out.

[0124] Advantageously, the phase of cleaning is carried out by means of the milling tool 13. In actual facts, the phase of cleaning and the phase of machining can be carried out using the same tool and on board the same machine, although it cannot be ruled out that they can be carried out on separate machines.

[0125] The phase of cleaning is carried out by the movement of the milling tool 13 along at least one substantially vertical direction of milling F and the milling tool 13 is arranged transversely with respect to the direction of milling F.

[0126] In accordance with the preferred embodiment, the direction of milling F substantially coincides with the direction of work Wl, W2.

[0127] Advantageously, the phase of cleaning is carried out simultaneously on both bars 3, 7. In detail, when moving along the direction of milling F, the milling tool 13 is placed in contact on one side with the residual bar 7 and on the other side with the second bar 3.

[0128] More specifically, to perform the phase of cleaning, the bars 3, 7 are brought closer together at a mutual distance less than the diameter of the milling tool 13 which, when moving along the direction of milling F, comes into contact with both ending surfaces 4, 5, smoothing them. In accordance with the preferred embodiment, the phase of cleaning is carried out after the phase of positioning and before the phase of machining, i.e., after the first bar 2 has been cut. It cannot, however, be ruled out that the phase of cleaning may be carried out before the phase of cutting, i.e., on the starting bars.

[0129] According to a further aspect, the present invention also refers to a plant for the production of reinforcement bars for window / door frame profiled elements, indicated in the attached drawings with reference numeral 1.

[0130] The plant 1 comprises holding means 6 adapted to hold at least a first bar 2 and a second bar 3 made of at least one metallic material and extending along their respective longitudinal directions, each provided at their respective ends with a first ending surface 4 and with a second ending surface 5 substantially perpendicular to the relevant longitudinal direction.

[0131] In particular, the holding means 6 comprise a holding plane 17 adapted to receive and support the bars 2, 3 arranged substantially side by side and parallel to each other.

[0132] The plant 1 also comprises cutting means 8 adapted to cut the first bar 2 to obtain at least one reinforcement bar insertable within a relevant window / door frame profiled element and a relevant residual bar 7 provided with the second ending surface 5.

[0133] The cutting means 8 are intended to perform the cutting phase of the present process.

[0134] The cutting means 8 comprise a cutting device 24 adapted to cut the bar 2, 3, 10 along a cutting plane transverse to the relevant longitudinal direction.

[0135] In the embodiment shown in the figures, the cutting plane is substantially perpendicular to the longitudinal direction. It cannot, however, be ruled out that the cutting plane may be inclined with respect to the longitudinal direction.

[0136] Still with reference to the embodiment shown in the figures, the cutting device 24 comprises a blade tool.

[0137] However, alternative embodiments are envisaged wherein the cutting device 24 uses a different technology and, e.g., comprises a plasma device.

[0138] In accordance with the embodiment shown in the figures, the bars 2, 3, 7, 10 are moved with respect to the cutting means 8 by means of positioning means 9 with which the plant 1 is provided and adapted to move the bars 2, 3, 7, 10 along the direction of forward movement D. The positioning means 9 are intended to perform the phase of positioning of the present process. More specifically, the positioning means 9 are configured to gradually move the bars 2, 3, 7, 10 towards the cutting means 8.

[0139] In particular, the positioning means 9 are adapted to move each bar 2, 3, 7, 10 from an operating station, defined on the holding means 6, to a cutting station, defined on the cutting means 8.

[0140] More specifically, the positioning means 9 determine the forward movement of the first bar 2 with respect to the cutting means 8 by a distance corresponding to the length of the reinforcement bar to be produced.

[0141] The positioning means 9 comprise at least one pusher body 19 adapted to abut against the second ending surface 5 of the first bar 2.

[0142] The pusher body 19 is movable, in a known manner, sliding along the direction of forward movement D to push the first bar 2 from the operating station to the cutting station.

[0143] The plant 1 also comprises retaining means 25 adapted to retain the residual bar 7 and the second bar 3 aligned with each other with respect to the longitudinal directions, with the second ending surface 5 of the residual bar 7 facing the first ending surface 4 of the second bar 3.

[0144] The retaining means 25 comprise a first retaining assembly 26 adapted to retain the residual bar 7 and a second retaining assembly 27 adapted to retain the second bar 3.

[0145] Each of the retaining assemblies 26, 27 comprises a substantially horizontal resting plane 28 adapted to receive and support the relevant bar 3, 7 and a substantially vertical abutment wall 29 parallel to the longitudinal directions and adapted to receive and stop the relevant bar 3, 7.

[0146] Each of the retaining assemblies 26, 27 also comprises at least one clamping assembly 30 that can be activated to hold the bars 3, 7 in place.

[0147] The plant 1 also comprises joining means 11 adapted to join the second bar 3 to the residual bar 7 by means of resistance butt welding of the residual bar 7 and of the second bar 3, carried out by means of the flow of current through the ending surfaces 4, 5 facing each other to obtain a recovered bar 10. The joining means 11 are intended to perform the joining phase of the present process.

[0148] In accordance with the preferred embodiment, the joining means 11 comprise a resistance welding unit 20 adapted to butt weld the residual bar 7 and the second bar 3 by means of the flow of current through the ending surfaces 4, 5 facing each other.

[0149] The resistance welding unit 20 comprises the electrode assemblies 14, 15.

[0150] Usefully, the electrode assemblies 14, 15 are associated with the retaining means 25.

[0151] Specifically, the first electrode assembly 14 is associated with the abutment wall 29 of the first retaining assembly 26 and the second electrode assembly 15 is associated with the abutment wall 29 of the second retaining assembly 27.

[0152] The electrode assemblies 14, 15 can be moved with respect to the retaining means 25 between a home position, wherein they are moved away from the residual bar 7 and from the second bar 3, and a work position, wherein they are in contact with the residual bar 7 and with the second bar 3 and determine the flow of current.

[0153] More specifically, the resistance welding unit 20 comprises actuator means of the pneumatic type adapted to move the electrode assemblies 14, 15 between the home position and the work position.

[0154] In accordance with the embodiment shown in the figures, each of the electrode assemblies 14, 15 comprises a plurality of substantially flat electrodes 35 adapted to adhere to the surface of the bars 3, 7. In particular, the electrodes 35 are of the braided copper electrode type. It cannot, however, be ruled out that the electrodes 35 may be of a different type.

[0155] In this way, the electrode assemblies 14, 15 have an extended surface in contact with the respective bars 3, 7, which allows effective current transmission and avoids excessive heat generation.

[0156] The bars 3, 7 are then brought closer together to form the electric arc (Figures 5 and 6).

[0157] For this purpose, the joining means 11 comprise a displacement system 31 adapted to mutually move the retaining assemblies 26, 27 between an away position, wherein the ending surfaces 4, 5 are spaced apart from each other, and a close position, wherein the ending surfaces 4, 5 are joined and pressed together.

[0158] Specifically, the retaining assemblies 26, 27 are both movable with respect to the reference plane P.

[0159] The displacement system 31 comprises at least one guiding body 32 extending parallel to the direction of forward movement D and supporting the resting plane 28 of a respective retaining assembly 26, 27 by sliding.

[0160] The displacement system 31 then comprises an actuator adapted to move the retaining assembly 26, 27 on the guiding body 32.

[0161] The actuator allows the position of the retaining assemblies 26, 27 to be adjusted during the phase of joining and the pressure applied to the bars 3, 7 to be adjusted during the phase of compression.

[0162] According to the invention, the plant 1 comprises removal means 12 configured to remove part of the metallic material from at least one of said ending surfaces 4, 5.

[0163] The removal means 12 are intended to perform the machining phase of the present process.

[0164] In accordance with the preferred embodiment, the removal means 12 are also intended to perform the phase of cleaning of the present process. It cannot, however, be ruled out that the phase of cleaning may be carried out by separate cleaning means.

[0165] Furthermore, preferably, the removal means 12 and the joining means 11 are mounted on board the same machine, so that the phase of joining can be carried out immediately after the phase of machining and / or of cleaning. It cannot, however, be ruled out that the removal means 12 and the joining means 11 may be mounted on separate machines, not necessarily placed in succession with each other.

[0166] Furthermore, the components of this plant 1 can be mounted on respective machines located within the same production plant or even in separate plants. For example, the cutting means 8 may be mounted on a different and separate machine with respect the joining means 11 and / or the removal means 12. In other words, three separate machines may also be provided: one provided with the cutting means 8, one provided with the joining means 11 and one provided with the removal means 12.

[0167] In this case, the respective phases of the present process may also be carried out at different times and not necessarily during the same production cycle.

[0168] In accordance with the embodiment shown in the figures, the retaining means 25, the joining means 11 and the removal means 12 are mounted on board the same machine, indicated in the drawings with reference numeral 21.

[0169] Advantageously, the removal means 12 are placed between the first retaining means 25 and the second retaining means 25.

[0170] The removal means 12 are configured to remove the metallic material on both the residual bar 7 and the second bar 3.

[0171] Advantageously, the removal means 12 are configured to remove the metallic material simultaneously on both ending surfaces 4, 5.

[0172] The removal means 12 comprise the milling tool 13 described above.

[0173] As mentioned above, the milling tool 13 can be moved along the direction of work Wl, W2 and / or along the direction of milling F.

[0174] For this purpose, the removal means 12 comprise a movement assembly 22 adapted to move the milling tool 13 along the direction of work Wl, W2 and comprising: a guiding unit 23 that runs parallel to the direction of work Wl, W2 and supports the milling tool 13 by sliding; a motorized actuator 34 adapted to move the milling tool 13 on the guiding unit 23.

[0175] In addition, the removal means 12 usefully comprise an intake assembly 36 adapted to suck up the metallic residues generated by the removal of metallic material.

[0176] The intake assembly 36, in addition to preventing the dispersion of dust and metallic chips in the workplace, with a consequent risk to the safety of the plant, also prevents them from settling on the ending surfaces 4, 5, thus affecting the subsequent phase of joining.

[0177] The intake assembly 36 comprises an intake motor 37 and a conveyor body 38 arranged to partly surround the milling tool 13 and connected to the intake motor 37.

[0178] Specifically, the intake motor 37 generates a vacuum inside the conveyor body 38, which allows the metallic residues generated during removal to be sucked up.

[0179] Usefully, the conveyor body 38 comprises at least two inlet openings 39, 40 for the metallic residues, arranged facing respective retaining assemblies 26, 27.

[0180] In accordance with the embodiment shown in the figures, the inlet openings 39, 40 comprise a first opening 39 arranged on top of the milling tool 13 and a second opening 40 arranged below the milling tool 13.

[0181] In detail, the opening 39, 40 is arranged on top of or below the milling tool 13 depending on the way of rotation of the latter and, consequently, on the direction imparted to the metallic residues during removal.

[0182] It has in practice been ascertained that the described invention achieves the intended objects and, in particular, the fact should be emphasized that the process and plant for the production of reinforcement bars for window / door frame profiled elements ensure effective joining of the bars and avoid excessive waste of resources.

[0183] Furthermore, this process and plant make it possible to reduce the production and management costs of the production plant.

Claims

CLAIMS1) Process for the production of reinforcement bars for window / door frame profiled elements, comprising the following phases: supplying at least one first bar (2) and at least one second bar (3) made of at least one metallic material and extending along relevant longitudinal directions, each provided, at the respective ends, with a first ending surface (4) and with a second ending surface (5) substantially perpendicular to said relevant longitudinal direction; cutting said first bar (2) to obtain at least one reinforcement bar insertable into a relevant window / door frame profiled element and a residual bar (7) provided with said second ending surface (5); positioning said second bar (3) aligned with said residual bar (7) with respect to said longitudinal directions, with the first ending surface (4) of said second bar (3) facing the second ending surface (5) of said residual bar (7); joining said second bar (3) to said residual bar (7) by means of resistance butt welding of said second bar (3) and of said residual bar (7) carried out by means of the flow of current through said ending surfaces (4, 5) facing each other to obtain a recovered bar (10); characterized by the fact that, prior to said phase of joining, it comprises at least one phase of machining at least one of said ending surfaces (4, 5) carried out by removal of metallic material to obtain at least one machined surface (16a, 16b) and at least one protruding portion (18), partly defining said ending surface (4, 5) and protruding from said machined surface (16a, 16b) and by the fact that said phase of joining is carried out by means of the flow of current through said protruding portion (18).2) Process according to claim 1, characterized by the fact that said phase of machining is carried out by means of a milling tool (13) movable along a reference plane (P) substantially parallel to said ending surfaces (4, 5).3) Process according to one or more of the preceding claims, characterized by the fact that said milling tool (13) develops longitudinally within said reference plane (P) and by the fact that said phase of machining is carried out through the movement of said milling tool (13) along at least one substantially vertical direction of work (Wl, W2), said milling tool (13) being arranged transversely with respect to said direction of work (Wl, W2).4) Process according to one or more of the preceding claims, characterized by the fact that said phase of machining comprises a step of first milling and at least a step of second milling to obtain at least one first machined surface (16a), at least a second machined surface (16b) and a pair of protruding portions (18) opposite each other and placed between said first machined surface (16a) and said second machined surface (16b).5) Process according to one or more of the preceding claims, characterized by the fact that saidstep of first milling is carried out by the movement of said milling tool (13) along a first direction of work (Wl) and said step of second milling is carried out by the movement of said milling tool (13) along a second direction of work (W2) being directed opposite said first direction of work (Wl).6) Process according to one or more of the preceding claims, characterized by the fact that said phase of machining is carried out in a specular manner on both bars (3, 7), the at least one protruding portion (18) of one of the bars (3, 7) being arranged facing the protruding portion (18) of the other bar (3, 7).7) Process according to one or more of the preceding claims, characterized by the fact that said phase of machining is carried out simultaneously on both bars (3, 7).8) Process according to one or more of the preceding claims, characterized by the fact that, prior to said phase of machining, it comprises a phase of cleaning said ending surfaces (4, 5) carried out by means of removal of metallic material.9) Process according to one or more of the preceding claims, characterized by the fact that said phase of cleaning is carried out by means of said milling tool (13).10) Process according to one or more of the preceding claims, characterized by the fact that said phase of cleaning is carried out simultaneously on both bars (3, 7).11) Plant (1) for the production of reinforcement bars for window / door frame profiled elements, comprising: holding means (6) adapted to hold at least one first bar (2) and one second bar (3) made of at least one metallic material and extending along relevant longitudinal directions, each provided, at the respective ends, with a first ending surface (4) and a second ending surface (5) substantially perpendicular to said relevant longitudinal direction; cutting means (8) adapted to cut said first bar (2) to obtain at least one reinforcement bar insertable within a relevant window / door frame profiled element and a relevant residual bar (7) provided with said second ending surface (5); retaining means (25) adapted to retain said residual bar (7) and said second bar (3) aligned with each other with respect to said longitudinal directions, with said second ending surface (5) of the residual bar (7) facing the first ending surface (4) of said second bar (3); joining means (11) adapted to join said second bar (3) to said residual bar (7) by means of butt welding of said residual bar (7) and said second bar (3) carried out by means of the flow of current through said ending surfaces (4, 5) facing each other to obtain a recovered bar (io); characterized by the fact that it comprises removal means (12) configured to remove part of the metallic material from at least one of said ending surfaces (4, 5).12) Plant (1) according to claim 11, characterized by the fact that said retaining means (25)comprise a first retaining assembly (26) adapted to retain said residual bar (7) and a second retaining assembly (27) adapted to retain said second bar (3), said removal means (12) being placed between said first retaining means (25) and said second retaining means (25).13) Plant (1) according to claim 11, characterized by the fact that said removal means (12) are configured to remove the metallic material simultaneously from both said ending surfaces (4, 5).14) Plant (1) according to claim 11, characterized by the fact that said removal means (12) comprise at least one milling tool (13) which longitudinally runs along an axis of development (A) and is rotatable on itself around said axis of development (A).15) Plant (1) according to claim 14, characterized by the fact that said axis of development (A) is inclined to the horizon by a predefined angle of work (a).16) Plant (1) according to claim 15, characterized by the fact that said angle of work (a) is of between 5° and 70°.17) Plant (1) according to claim 14, characterized by the fact that said milling tool (13) is movable along at least one direction of work (Wl, W2) substantially vertical and coplanar to said axis of development (A).18) Plant (1) according to claim 14, characterized by the fact that said removal means (12) comprise a movement assembly (22) adapted to move said milling tool (13) along said direction of work (Wl, W2) and comprising: a guiding unit (23) that runs parallel to said direction of work (Wl, W2) and supports said milling tool (13) by sliding; a motorized actuator (34) adapted to move said milling tool (13) on said guiding unit (23).19) Plant (1) according to claim 11, characterized by the fact that said removal means (12) comprise an intake assembly (36) adapted to suck up the residues of metallic material generated by the removal of metallic material.20) Plant (1) according to claim 19, characterized by the fact that said intake assembly (36) comprises an intake motor (37) and a conveyor body (38) arranged to partly surround said milling tool (13) and connected to said intake motor (37).21) Plant (1) according to claim 20, characterized by the fact that said conveyor body (38) comprises at least two inlet openings (39, 40) for said metallic residues, arranged facing respective retaining means (25) and comprising a first opening (39) arranged on top of said milling tool (13) and a second opening (40) arranged below said milling tool (13).

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