Process and equipment for manufacturing reinforcing bars for molded elements for window / door frames

Abstract

The process comprises the following phases: providing at least one first bar (2) and at least one second bar (3) made of at least one metallic material, extending along an associated longitudinal direction and provided with a first end surface (4) and a second end surface (5), respectively; cutting the first bar (2) to obtain one reinforcing bar (100) insertable in an associated molding element for a window / door frame and a remaining bar (7) provided with a second end surface (5); positioning the second bar (3) substantially parallel to said longitudinal direction and aligned with the remaining bar (7) with respect to a forward movement direction (D), the first end surface (4) of the second bar (3) facing the second end surface (5) of the remaining bar (7); and resistance butt welding of the second bar (3) and the remaining bar (7) performed by current flow through the mutually facing end surfaces (4, 5) to obtain a welded bar (10).

Description

[Technical field]

[0001] The present invention relates to a process and equipment for manufacturing reinforcing bars for window / door frames. [Background technology]

[0002] In the window / door frame industry, it is known to use bars to reinforce molded elements for window / door frames made from plastic materials. The reinforcing bars are generally made from metallic materials such as steel or other alloys and are inserted into the internal cavities of the molded elements to give greater strength and toughness to the finished window / door frame. Furthermore, the reinforcing bars act as supports for further mechanical parts necessary to operate the window / door frame, such as hinges, handles, locking systems, etc.

[0003] Known manufacturing processes and associated equipment include cutting metal bars according to the length of the molded element to be reinforced in order to precisely obtain the associated reinforcement bars, which can be obtained, for example, by extrusion of molten metal material or by folding a metal sheet.

[0004] The metal bar is generally of extended length, for example 5-6 meters, and can be cut multiple times to obtain many reinforcing bars.

[0005] The reinforcing bars can be gradually inserted directly into the associated forming element at the end of each cutting operation, or can be stored together and installed later.

[0006] However, known processes and equipment suffer from several drawbacks.

[0007] As mentioned above, the metal bars are provided with dimensions having a length of about 5-6 meters, and the cutting operation inevitably results in the formation of remaining ends of too short size, which are used as reinforcing bars.

[0008] Therefore, such remaining bars are discarded and new metal bars undergo cutting.

[0009] After the first bar has been machined, the remaining remaining bar then needs to be removed from the production line to make space for the second bar.

[0010] This operation, in addition to interrupting production operations, results in the extension of the associated time schedules and also results in the formation of large amounts of waste which significantly impacts the production costs of the reinforcing bars.

[0011] In effect, the remaining unwanted bars are sent for disposal, thereby reducing the amount of usable material. Furthermore, this inconvenience necessitates the purchase of excess metal bars to ensure the production of the required number of reinforcing bars. Summary of the Invention [Problem to be solved by the invention]

[0012] The main object of the present invention is to devise a process and an installation for manufacturing reinforcing bars for molded elements for window / door frames, which makes it possible to avoid the formation of waste.

[0013] Another object of the invention is to devise a process and an installation for manufacturing reinforcing bars for molded elements for window / door frames that makes it possible to avoid interruptions to the manufacturing process and to optimize the operating schedule.

[0014] A further object of the present invention is to devise a process and equipment for manufacturing reinforcing bars for molding elements for window / door frames, which makes it possible to maintain production and to keep the operating costs of the production facility low.

[0015] Another object of the present invention is to devise a process and equipment for manufacturing reinforcing bars for molding elements for window / door frames, which is simple, rational, easy and effective to use, as well as being able to overcome the aforementioned drawbacks of the prior art within the scope of a cost-effective solution.

[0016] The aforementioned object is achieved by the inventive process for manufacturing reinforcing bars for molded elements for window / door frames having the features of claim 1.

[0017] The aforementioned object is furthermore achieved by the inventive process for manufacturing a reinforcing bar for a moulded element for a window / door frame having the features of claim 13.

[0018] Other features and advantages of the present invention will become more apparent from the description of preferred, but not exclusive, embodiments of a process and an installation for manufacturing reinforcing bars for molded elements for window / door frames, illustrated as suggestive but non-limiting examples in the accompanying drawings, in which: [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is an axonometric view of an installation according to the invention; [Diagram 2] FIG. 2 is an axonometric view of the installation during execution of the remaining bar positioning phase of the process according to the invention. [Diagram 3] FIG. 2 shows an axonometric view of the installation during execution of the second bar positioning phase of the process according to the invention. [Figure 4] FIG. 2 is an axonometric view of the installation during the execution of a subphase of the application of the electrode assembly of the process according to the invention. [Diagram 5] FIG. 2 is an axonometric view of the installation during execution of the joining subphase of the process according to the invention. [Figure 6] 3 is a top view of the welding tool during performance of the joining subphase of the process according to the invention; FIG. [Figure 7]FIG. 2 is a side view of the welding means when performing the compression subphase of the process according to the invention; [Figure 8] FIG. 2 is an axonometric view of the installation during execution of the remaining bar cutting phase of the process according to the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] With particular reference to these figures, the number 1 generally indicates an installation that can be used in an embodiment of the present process for manufacturing reinforcing bars for molded elements for window / door frames.

[0021] The process according to the invention first comprises a phase of providing at least one first bar 2 and at least one second bar 3 made from at least one metallic material.

[0022] The bars 2, 3 are elongated bodies made of at least one metallic material, for example iron, steel or another alloy, and can be obtained, for example, by extrusion of such molten metallic material or by folding a metal sheet.

[0023] In the embodiment shown in the figures, the bars 2, 3 are hollow and have a square cross section.

[0024] However, it cannot be excluded that the bars 2, 3 are provided with a different shape, for example a "U-shaped", "L-shaped" cross section or are of the slab-shaped type. Likewise, it cannot be excluded that the bars 2, 3 are solid, i.e. not hollow.

[0025] The bars 2, 3 extend along an associated longitudinal direction and are each provided with a first end surface 4 and a second end surface 5 substantially perpendicular to the associated longitudinal direction.

[0026] The installation 1 comprises holding means 6 adapted to hold at least a first bar 2 and a second bar 3. Suitably, as will be explained further on in the present disclosure, the holding means 6 is adapted to hold a plurality of bars. However, for ease of explanation, only the first bar 2 and the second bar 3 will be referred to in the remainder of the present disclosure.

[0027] The process includes a phase of cutting the first bar 2 to obtain at least one reinforcing bar 100 that can be inserted into an associated molding element for the window / door frame, and a remaining bar 7 provided with a second end surface 5.

[0028] For this purpose, the installation 1 is provided with cutting means 8 adapted to cut the first bar 2, by means of which a cutting phase is carried out.

[0029] Depending on the length of the reinforcing bars 100 it is intended to obtain, the first bar 2 can be cut several times in order to obtain many reinforcing bars 100 .

[0030] The process then involves repeating the phase of cutting the first bar 2 according to the length of the reinforcing bar 100 desired.

[0031] The remaining bar 7 corresponds to the end section of the first bar 2 resulting from the cutting operation, the first bar 2 being too short to be used as a reinforcing bar 100 .

[0032] The process therefore includes a phase of positioning a second bar 3 in alignment with the remaining bar 7 relative to the forward movement direction D substantially parallel to the longitudinal direction, with the first end surface 4 of the second bar 3 facing the second end surface 5 of the remaining bar 7.

[0033] For this purpose, the installation 1 comprises positioning means 9 adapted to move each of the bars 2, 3, 7 along a forward movement direction D.

[0034] The process then includes a phase of resistance butt welding of the second bar 3 and the remaining bar 7 performed by current flow through their mutually facing end surfaces 4 , 5 to obtain a welded bar 10 .

[0035] In fact, the installation 1 comprises resistance welding means 11 adapted to carry out this welding phase.

[0036] In the context of the present disclosure, the phrase "butt weld" refers to a type of welding performed by means of juxtaposing the end surfaces 4, 5 of the second bar 3 and the remaining bar 7.

[0037] As known to those skilled in the art, resistance butt welding is an autogenous pressure welding process in which metallic materials are heated by electrical resistance.

[0038] Thus, the welded bar 10 is formed by the remaining bar 7 and by the second bar 3 joined together at the weld area 12 .

[0039] Advantageously, the process involves repeated phases of cutting, positioning and welding the weld bar 10 .

[0040] The welded bar 10 then undergoes a re-cutting phase to produce a new reinforcing bar 100, and any new remaining bar 7 is welded to the subsequent bar.

[0041] The process therefore makes it possible to carry out a continuous production of the reinforcing bars 100, avoiding the formation of waste.

[0042] The remaining bar 7 resulting from the cutting operation of the first bar 2 is in fact always made whole by the subsequent welding to the second bar 3 .

[0043] Advantageously, the phases are carried out successively on the same working line 13 extending along the forward movement direction D.

[0044] More specifically, with reference to the installation 1 shown in the figure, the working line 13 is defined partly by the holding means 6, by the resistance welding means 11 and partly by the cutting means 8, which means are arranged successively to one another along the forward movement direction D.

[0045] The process reduces the time and costs associated with production by allowing interruptions in the production process to be avoided.

[0046] The resistance welding means 11 comprises electrode assemblies 14, 15 available to the second bar 3 and to the remaining bar 7 and adapted to determine the current flow.

[0047] Usefully, the welding phase includes a sub-phase of applying electrode assemblies 14, 15 to the second bar 3 and the remaining bar 7 at points where the associated end surfaces 4, 5 are positioned to determine the current flow.

[0048] In particular, the electrode assemblies 14 , 15 comprise a first electrode assembly 14 that is available to the remaining bar 7 and a second electrode assembly 15 that is available to the second bar 3 .

[0049] The resistance welding means 11 also comprises a transformer assembly 16 connected to the electrode assemblies 14, 15. For simplicity, the connections between the electrode assemblies 14, 15 and the transformer assembly 16 are not shown in the figures.

[0050] The welding phase also includes a sub-phase in which the end surfaces 4, 5 are joined together, resulting in the formation of an electric arc.

[0051] As is well known, an electric arc is an electrical discharge created between two metal parts that are moving close together and connected in an electric circuit.

[0052] In particular, the joining sub-phase is carried out by the mutual approach of the second bar 3 and the remaining bar 7 .

[0053] As the end surfaces 4, 5 move towards each other, the electrical circuit tends to open and close repeatedly due to the mechanical repulsion that inevitably occurs, which results in the formation of an electrical arc which, in this particular case, simultaneously produces high voltages in combination with high currents.

[0054] The electric arc simultaneously causes an intense generation of heat due to the Joule effect, which makes it possible to reach even higher temperatures (3,000°C-4,000°C), resulting in a very rapid softening and ultimately melting of the metallic material.

[0055] More specifically, the electric arc causes the formation of a plasma, resulting in the generation of heat.

[0056] To achieve this, a high intensity current must be applied.

[0057] Advantageously, the current is in the range of 1KA to 20KA.

[0058] Preferably, the current is in the range of 5KA to 10KA.

[0059] By doing so, it is possible to generate large amounts of energy and thus to maximally optimize the welding process, thereby speeding up operation times.

[0060] The reduction of the operating time also makes it possible to limit the formation of oxides of the metallic material. As the temperature increases, in fact, the oxidation reactions affecting the metallic material of the bar become even more favorable, which can lead to the generation of large amounts of metal oxides, the presence of which impairs the entire welding process by making the weld area insufficiently resistant to mechanical stresses.

[0061] In the case of equal power, the aforementioned current intensity values ​​are obtained by reducing the voltage using the transformer assembly 16 .

[0062] Advantageously, the joining sub-phase is carried out so that the metallic material softens.

[0063] Usefully, the bonding sub-phase is carried out for a time period between 0.1 seconds and 10 seconds, preferably between 1 second and 5 seconds, even more preferably between 1.5 seconds and 2 seconds.

[0064] In particular, the joining sub-phase is carried out so as to cause the formation of a sufficient amount of softened metallic material that gives the weld area adequate strength, but nevertheless does not result in the creation of an excessively protruding weld bead.

[0065] In fact, this resistance welding phase makes it possible to minimize the formation of outwardly protruding weld beads.

[0066] Conventional welding processes, particularly those that include the use of filler material, such as covered electrode welding, can result in the formation of a substantial weld bead that protrudes from the weld area.

[0067] In this particular case, the presence of a protruding weld bead may prevent the insertion of the reinforcing bar into the associated molding element for the window / door frame: in fact, the reinforcing bar is generally provided with a section sized to fit into the cavity defined by the molding element for the window / door frame, and the protruding weld bead would prevent its insertion.

[0068] If a conventional welding process is applied, the reinforcing bar would consequently need to be subjected to further machining at the removal of such weld beads.

[0069] The present process therefore makes it possible to further solve this technical problem and to avoid subsequent machining of the reinforcing bar 100, and in this sense makes it possible to further shorten the production schedule.

[0070] More specifically, the joining sub-phase is performed such that the thickness of the protruding weld bead is less than a minimum value.

[0071] The minimum value is determined depending on the dimensions of the internal cavity of the molding element for the window / door frame and on the cross-sectional dimensions of the reinforcing bar 100. As a result, for example, in some cases a protruding bead of 2 mm thickness may still allow the reinforcing bar 100 to be inserted inside the associated molding element for the window / door frame, while in other cases even a protruding bead of 0.5 mm thickness may prevent this action.

[0072] Usefully, the bonding sub-phase is carried out after the phase of applying the electrode assemblies 14,15.

[0073] Thus, during the joining sub-phase, the second bar 3 and the remaining bar 7 are already connected to the transformer assembly 16 and as soon as the end surfaces 4, 5 reach the required minimum distance, an electric arc is formed, making the welding extremely fast and resulting in the aforementioned advantages.

[0074] However, an alternative embodiment is provided in which the bonding sub-phase is performed before the phase of applying the electrode assemblies 14, 15. In other words, the end surfaces 4, 5 are first bonded and placed in contact with each other, after which a voltage is applied to the second bar 3 and the remaining bar 7.

[0075] Finally, the welding phase includes a sub-phase of compressing the end surfaces 4, 5 against one another.

[0076] During this phase, the softened metal material of the end surfaces 4,5 joins intimately and, as a result of cooling, forms a weld area 12.

[0077] In particular, during the compression sub-phase, the electrode assembly 14, 15 moves away from the second bar 3 and from the remaining bars 7, thus interrupting the current flow and allowing the metallic material to cool.

[0078] Usefully, the compression sub-phase is carried out over a period of between 0.5 seconds and 7 seconds, preferably between 0.5 seconds and 1.5 seconds.

[0079] At the same time, the compression subphase is carried out at a pressure of 1 Pa to 10 MPa.

[0080] Following the welding phase, the second bar 3 and the remaining bar 7 are joined together by a weld area 12 which is provided with a substantially continuous, strong and contained weld bead.

[0081] Additionally, the process allows for autogenous welding, which, as known to those skilled in the art, allows for joining metallic materials without the use of filler materials.

[0082] A filler material is a material that is heated until it melts and transported to the area to be welded. Once solidified, the filler material acts as a bridge between the welds. However, the filler material is not necessarily the same as the metal parts being welded and may have different physical and mechanical properties. Furthermore, welding times using filler materials are generally very long.

[0083] The resistance welding phase makes it possible to achieve, in a very short time, the continuity of the material of the reinforcing bar 100, making the weld area 12 sufficiently strong and robust, avoiding possible differences in the physical-mechanical behavior caused by the use of filler materials.

[0084] The process will now be explained in more detail with reference to the components of the installation 1.

[0085] The installation 1 comprises holding means 6 adapted to hold at least a first bar 2 and a second bar 3 .

[0086] In particular, the holding means 6 comprises a holding surface 17 adapted to receive and support the bars 2, 3 arranged substantially side by side and parallel to one another.

[0087] More specifically, the retaining means 6 comprises a set of arms 18 extending along an associated deployment direction, arranged substantially parallel to one another and defining a retaining surface 17 .

[0088] The arms 18 are adapted to hold the bars 2,3 with an associated longitudinal direction extending substantially perpendicular to the deployment direction.

[0089] The installation 1 also comprises positioning means 9 associated with the holding means 6 and adapted to move the bars 2, 3, 7, 10 along the forward movement direction D.

[0090] More specifically, the positioning means 9 are configured to move the bars 2 , 3 , 7 , 10 so that they move towards the cutting means 8 .

[0091] In particular, the positioning means 9 are adapted to move each of the bars 2 , 3 , 7 , 10 from a working platform defined in the holding means 6 to a cutting platform defined in the cutting means 8 .

[0092] The process comprises a phase of movement of the first bar 2 along a forward movement direction D carried out by positioning means 9 (FIG. 1).

[0093] More specifically, the positioning means 9 determine the forward movement of the first bar 2 relative to the cutting means 8 over a distance corresponding to the length of the reinforcing bar 100 to be produced.

[0094] The positioning means 9 comprise at least one pusher body 19 adapted to abut against the second end surface 5 of the first bar 2 .

[0095] The pusher body 19 is movable by sliding along a forward movement direction D and pushes the first bar 2 from the working table to the cutting table.

[0096] The positioning means 9 also comprise at least one guiding unit 20 associated with the holding means 6, which extends parallel to the forward movement direction D and supports the pusher body 19 by sliding.

[0097] The positioning means 9 in turn comprise at least one movement unit 21 adapted to move the pusher body 19 by sliding along a forward movement direction D.

[0098] The movement unit 21 comprises a rack body 22 extending parallel to the forward movement direction D, a pinion associated with the pusher body 19 and meshing with the rack body 22, and an actuator device 23 connected to the pinion and adapted to rotate and set the pinion.

[0099] Rotation of the pinion causes the pusher body 19 to slide along the forward motion direction D.

[0100] The movement unit 21 allows a very precise and accurate movement of the bars 2, 3, 7, 10, allowing their forward movement over a distance corresponding to the length of the reinforcing bar 100 that one wishes to obtain.

[0101] The installation 1 also comprises cutting means 8 adapted to cut the bars 2 , 3 , 10 .

[0102] The cutting means 8 comprise a cutting device 24 adapted to cut the bars 2, 3, 10 along a cutting plane lying transverse to the associated longitudinal direction.

[0103] In the embodiment shown in the figures, the cutting plane is substantially perpendicular to the longitudinal direction, however, it cannot be excluded that the cutting plane can be inclined with respect to the longitudinal direction.

[0104] Again, referring to the embodiment shown in the figures, the cutting device 24 comprises a blade tool.

[0105] However, there are alternative embodiments in which the cutting device 24 comprises a plasma device.

[0106] Upon completion of the cutting operation, the process includes a phase of positioning the remaining bar 7 on the welding table (FIG. 2).

[0107] The welding table is defined by a resistance welding means 11 positioned between the holding means 6 and the cutting means 8 .

[0108] The positioning phase of the remaining bars 7 is carried out by the positioning means 9 .

[0109] The process therefore includes a phase of positioning a second bar 3 in alignment with the remaining bar 7, with the first end surface 4 of the second bar 3 facing the second end surface 5 of the remaining bar 7 (Figure 3).

[0110] The phase of positioning the second bar 3 is also carried out by the positioning means 9 .

[0111] The installation 1 also comprises holding means 25 adapted to hold the remaining bar 7 and the second bar 3 .

[0112] The holding means 25 is associated with the resistance welding means 11 .

[0113] The holding means 25 comprises a first holding assembly 26 for the remaining bar 7 and a second holding assembly 27 for the second bar 3 .

[0114] Each of the retaining assemblies 26, 27 comprises a bearing surface 28 which is substantially horizontal and adapted to receive and support the associated bar 3, 7, and an abutment wall 29 which is substantially perpendicular and parallel to the direction of forward movement D and adapted to abut and receive the associated bar 3, 7.

[0115] Each of the holding assemblies also includes a clamping assembly 30 which is operable to maintain the bar 3,7 fixed to the associated abutment wall 29.

[0116] A clamp assembly 30 is associated with the bearing surface 28 and is a type of device that is actuated horizontally by a pneumatic cylinder.

[0117] Once secured using the retaining means 25, the bars 3, 7 are welded together.

[0118] Thus, the electrode assemblies 14, 15 are applied to the associated bars 3, 7 (FIG. 4).

[0119] Usefully, the electrode assemblies 14 , 15 are associated with a retaining means 25 .

[0120] In particular, the first electrode assembly 14 is associated with an abutment wall 29 of the first holding assembly 26 and the second electrode assembly 15 is associated with an abutment wall 29 of the second holding assembly 27 .

[0121] The electrode assemblies 14, 15 are movable relative to the holding means 25 between a home position in which they are moved away from the remaining bar 7 and the second bar 3, and a working position in which they are in contact with the remaining bar 7 and the second bar 3 to cause a current flow.

[0122] More particularly, the resistance welding means 11 comprises actuating means 34 of the pneumatic type adapted to move the electrode assemblies 14, 15 between a home position and a working position.

[0123] According to the embodiment shown in the figures, the electrode assemblies 14, 15 each comprise a plurality of electrodes 35 which are substantially flat and adapted to attach to the surfaces of the bars 3, 7. In particular, the electrodes 35 are braided copper type electrodes.

[0124] Thus, the electrode assemblies 14,15 have extended contact surfaces with the associated bars 3,7, which allows for efficient current transfer and avoids excessive heating.

[0125] The bars 3, 7 are then brought close to each other to form an electric arc (FIGS. 5 and 6).

[0126] For this purpose, the resistance welding means 11 comprises a displacement system 31 adapted to move the holding assemblies 26, 27 relative to one another between a moved apart position in which the end surfaces 4, 5 are spaced apart from one another and a moved closer position in which the end surfaces 4, 5 are joined and pressed against one another.

[0127] In particular, the first retaining assembly 26 is fixed relative to the resistance welding means 11, while the second retaining assembly 27 is movable between a moved away position and a moved closer position.

[0128] However, the reverse configuration cannot be excluded, i.e., the first holding assembly 27 is fixed relative to the resistance welding means 11 while the second holding assembly 26 is movable between a moved away position and a moved closer position.

[0129] It cannot be excluded that both holding assemblies 26, 27 are also movable.

[0130] The displacement system 31 comprises a guide body 32 associated with the resistance welding means 11, which extends parallel to the forward movement direction D and supports, by sliding, the bearing surface 28 of the second holding assembly 27.

[0131] The displacement system 31 in turn comprises an actuator 33 positioned between the resistance welding means 11 and the second holding assembly 27 .

[0132] In particular, the actuator 33 comprises a fixed part associated with the resistance welding means 11 and a movable part connected to the bearing surface 28 of the second retaining assembly 27 .

[0133] Advantageously, the displacement system 31 comprises an electric actuator 33 .

[0134] The actuator 33 thus makes it possible to move the holding means 25 in a very precise and accurate manner, making it possible to adjust its position in time.

[0135] The process then includes a sub-phase of compression, also carried out by the displacement system 31 (FIG. 7).

[0136] In particular, the actuator 33 makes it possible to adjust the position of the holding assemblies 26, 27 during the bonding phase and to adjust the pressure applied to the bars 3, 7 during the compression phase.

[0137] At the end of welding, the electrode assemblies 14,15 move into a home position where the electrode assemblies are moved away from the bars 3,7 and the electrical circuit is opened, allowing the weld area 12 to cool.

[0138] Thereafter, the clamp assembly 30 also operates to release the weld bar 10 .

[0139] At this point, the positioning means 9 operates to move the welding bar 10 forward along the forward movement direction D, making it possible to repeat the phases of cutting, positioning and welding the welding bar 10 (FIG. 8).

[0140] According to a further aspect, the invention also refers to an installation 1 for manufacturing reinforcing bars 100 for molding elements for window / door frames.

[0141] The installation 1 according to the invention comprises: - holding means 6 adapted to hold at least one first bar 2 and one second bar 3, made from at least one metallic material, extending along an associated longitudinal direction and provided with a first end surface 4 and a second end surface 5, respectively, substantially perpendicular to the associated longitudinal direction; cutting means 8 adapted to cut the first bar 2 to obtain at least one reinforcing bar 100 insertable inside an associated molding element for a window / door frame and an associated remaining bar 7 provided with a second end surface 5; positioning means 9 adapted to move each of the bars 2, 3, 7 along at least one forward movement direction D substantially parallel to the associated longitudinal direction; - holding means 25 adapted to hold the remaining bar 7 and the second bar 3 aligned with each other relative to the forward movement direction D, the second end surface 5 of the remaining bar 7 facing the first end surface 4 of the second bar 3; - resistance welding means 11 adapted to butt-weld the remaining bar 7 and the second bar 3 by current flow through their mutually facing end surfaces 4, 5 to obtain a welded bar 10; Includes.

[0142] It has been confirmed in practice that the described invention achieves its intended purpose, in particular highlighting the fact that the process and the installation according to the invention for manufacturing reinforcing bars for moulding elements for window / door frames makes it possible to avoid the formation of waste: due to the phase of welding carried out by resistance welding means, the remaining bar is always welded to the succeeding bar.

[0143] Furthermore, the process and equipment of the present invention allows for avoiding interruptions to the manufacturing process and optimizing operational schedules.

[0144] In this sense, the process and the installation according to the invention therefore make it possible to keep the production costs and the operating costs of the production facility low.

Claims

1. A process for manufacturing reinforcing bars for moulded elements for window / door frames, said process comprising the following phases: providing at least one first bar (2) and at least one second bar (3) made from at least one metallic material, extending along an associated longitudinal direction and provided with a first end surface (4) and a second end surface (5), respectively, substantially perpendicular to said associated longitudinal direction; a phase of cutting said first bar (2) to obtain at least one reinforcing bar (100) that can be inserted into an associated molding element for a window / door frame and a remaining bar (7) provided with said second end surface (5); a positioning phase of the second bar (3) aligned with the remaining bars (7) in a forward movement direction (D) substantially parallel to the longitudinal direction, the first end surface (4) of the second bar (3) facing the second end surface (5) of the remaining bars (7); a phase of resistance butt welding of the second bar (3) and the remaining bar (7) performed by a current flow through the mutually facing end surfaces (4, 5) to obtain a welded bar (10); A process characterized by the fact that it involves

2. 2. The process according to claim 1, characterized by the fact that it comprises repeated phases for cutting, positioning and welding the welding bar (10).

3. 3. A process according to claim 1 or 2, characterized by the fact that said phases are carried out successively on the same working line (13) extending along said forward movement direction (D).

4. A process according to any one of claims 1 to 3, characterized by the fact that the welding phase comprises a sub-phase of applying an electrode assembly (14, 15) to the second bar (3) and to the remaining bar (7) at points where the relevant end surfaces (4, 5) are located to determine the current flow.

5. A process according to any one of the preceding claims, characterized by the fact that said electric current has an intensity comprised between 1 KA and 20 KA.

6. A process according to any one of the preceding claims, characterised by the fact that the welding phase comprises a sub-phase which joins the end surfaces (4, 5) together, resulting in the formation of an electric arc.

7. A process according to any one of the preceding claims, characterised by the fact that the bonding sub-phase is carried out after the phase of applying the electrode assembly (14, 15).

8. 7. A process according to claim 6, characterized by the fact that the bonding sub-phase is carried out before the phase of applying the electrode assembly (14, 15).

9. 9. A process according to any one of the preceding claims, characterised by the fact that the bonding subphase is carried out for a time between 0.1 seconds and 10 seconds, preferably between 1 second and 5 seconds, even more preferably between 1.5 seconds and 2 seconds.

10. A process according to any one of the preceding claims, characterised by the fact that the welding phase comprises a sub-phase of compressing the end surfaces (4, 5) against one another.

11. A process according to any one of the preceding claims, characterised by the fact that the compressing sub-phase is carried out for a time ranging from 0.5 seconds to 7 seconds, preferably from 0.5 seconds to 1.5 seconds.

12. A process according to any one of the preceding claims, characterized by the fact that the compressing subphase is carried out at a pressure between 1 Pa and 10 MPa.

13. An installation (1) for manufacturing reinforcing bars for molding elements for window / door frames, said installation (1) comprising: holding means (6) adapted to hold at least one first bar (2) and one second bar (3), made from at least one metallic material, extending along an associated longitudinal direction and provided with a first end surface (4) and a second end surface (5), respectively, substantially perpendicular to said associated longitudinal direction; cutting means (8) adapted to cut said first bar (2) to obtain at least one reinforcing bar (100) insertable inside an associated molding element for a window / door frame and an associated remaining bar (7) provided with said second end surface (5); positioning means (9) adapted to move each of said bars (2, 3, 7) along at least one forward movement direction (D) substantially parallel to said associated longitudinal direction; holding means (25) adapted to hold the remaining bar (7) and the second bar (3) aligned with each other relative to the forward movement direction (D), the second end surface (5) of the remaining bar (7) facing the first end surface (4) of the second bar (3); resistance welding means (11) adapted to butt-weld the remaining bar (7) and the second bar (3) by current flow through the mutually facing end surfaces (4, 5) to obtain a welded bar (10); The facility (1) is characterized by the fact that it includes:

14. 14. The installation (1) according to claim 13, characterized by the fact that the holding means (6), the resistance welding means (11) and the cutting means (8) are arranged successively along the same working line (13) and along the forward movement direction (D).

15. 15. Installation (1) according to claim 13 or 14, characterized by the fact that the resistance welding means (11) comprises an electrode assembly (14, 15) associated with the holding means (25), the electrode assembly (14, 15) being movable relative to the holding means (25) between a home position in which it is moved away from the remaining bar (7) and the second bar (3) and a working position in which it is in contact with the remaining bar (7) and the second bar (3) and causes the current flow.

16. Installation (1) according to any one of claims 13 to 15, characterised by the fact that the holding means (25) comprise a first holding assembly (26) for the remaining bar (7) and a second holding assembly (27) for the second bar (3), and by the fact that the resistance welding means (11) comprise a displacement system (31) adapted to move the holding assemblies (26, 27) relative to one another between a moved apart position, in which the end surfaces (4, 5) are spaced apart from one another, and a moved closer position, in which the end surfaces (4, 5) are joined and pressed against one another.

17. Installation (1) according to any one of claims 13 to 16, characterised by the fact that the displacement system (31) comprises an electric actuator (33).

18. Installation (1) according to any one of claims 13 to 17, characterised by the fact that said cutting means (8) comprise a blade tool.

19. Installation (1) according to any one of claims 13 to 17, characterised by the fact that the cutting means (8) comprise a plasma device.

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