WO2023094925A1 - Welding torch with integrated welding fume extraction system and device using said torch - Google Patents

Abstract

The present invention concerns a welding torch (10) comprising a main body (12) and a terminal area (18) for welding provided with at least one suction path (F1) for the fumes generated during welding. The terminal area (18) comprises an electrode provided with an internal channel for the passage of a welding wire, a first conveyor element (20) externally associated with the electrode and suited to allow a shielding gas to be conveyed externally to the electrode and a second conveyor element (50) suited to be connected to the main body (12) and externally associated with the first conveyor element (20). The second conveyor element (50) interacts with the first conveyor element (20) in order to maintain the first conveyor element (20) in the operating position when the second conveyor element (50) is connected to the main body (12). A suction path (F1) suited to extract the fumes is defined between the first conveyor element (20) and the second conveyor element (50)

Description

WELDING TORCH WITH INTEGRATED WELDING FUME EXTRACTION SYSTEM AND DEVICE USING SAID TORCH.

TECHNICAL FIELD OF THE INVENTION

The present invention concerns the technical field of welding of metallic materials.

More specifically, the present invention concerns the production of a welding torch using GMAW (Gas Metal Arc Welding) technology.

Even more specifically, the present invention concerns the construction of a welding torch equipped with a welding fume extraction system.

The present invention also concerns a device using said torch.

DESCRIPTION OF THE STATE OF THE ART

The use of welding technologies for joining materials, typically metallic materials, is known in various sectors and especially in industry.

Welding technologies of a known type are grouped under the acronym GMAW (Gas Metal Arc Welding), also known as metal arc gas shielded welding, wherein the gas is commonly referred to as weld pool shielding gas. These include, in particular, MIG (Metal-Inert-Gas) welding or MAG (Metal- Active-Gas) welding, which substantially differ due to the different gas used for shielding the weld pool.

The known technologies require that the skilled operators who work on the material to be welded use special equipment.

For this purpose, said devices comprise an element suited to be handled by the operator, which is referred to as “torch” and is connected to a power supply unit by means of a cable.

The end of the torch is provided with a nozzle from which a welding material in the form of a wire and a quantity of shielding gas exit. Said devices of the known type exploit the effect deriving from the generation of an electric arc between the torch and the workpiece, wherein said electric arc melts the welding material with which the torch is fed. The melted welding material defines the welding area, or weld pool, and the weld pool is shielded by the atmosphere defined by the shielding gas that flows out through the nozzle of the torch itself.

The shielding gas is typically conveyed into the area to be welded through a system made up of pipes coming from a gas source, typically a gas cylinder, and reaching the inside of the nozzle, whose main function is exactly to direct the shielding gas towards the weld pool. At the same time, the wire of welding material is moved forward through the torch body by means of a suitable feeding mechanism, until it reaches the nozzle. To generate the electric arc, electric current is carried to a suitable electrically conductive element, or electrode. The electrode is typically made of copper and is arranged coaxially inside the nozzle. The torches of this type can be equipped with a suction system suited to extract the fumes deriving from the welding process.

An extraction system of the known type comprises a tubular suction element fixed between the torch body and the nozzle and equipped with side suction openings.

The welding fumes are extracted laterally and upstream of the nozzle to be discharged and/or treated.

It is known that welding torches are subjected to frequent maintenance operations intended to re-establish the ideal welding conditions from time to time, in particular by replacing the torch elements that are subject to heavy wear such as, for example, the electrode or the nozzle, which are generically referred to as consumables.

It is the object of the present invention to provide a welding torch that represents an alternative to the torches of known type.

It is a first object of the present invention to provide a welding torch that makes it possible to improve suction efficiency compared to the systems of known type.

It is another object of the present invention to provide a welding torch that simplifies the maintenance and/or replacement of consumable elements, in particular of the nozzle and/or the internal electrode, compared to the torches of known type.

SUMMARY OF THE PRESENT INVENTION

According to a first aspect of the present invention, the same concerns a welding torch made according to claim 1.

The present invention concerns a welding torch equipped with an integrated fume extraction system, said torch comprising a main body and a terminal area suited to be fed, through said main body, with a welding wire and a welding shielding gas, said terminal area being provided with at least one suction path for extracting the fumes generated during the welding process, said terminal area comprising:

- an electrode suited to be powered electrically and provided with an internal channel for the passage of said welding wire; - a first conveyor element externally associated with said electrode and suited to allow said shielding gas to be conveyed outside said electrode, said first conveyor element being provided with an outlet mouth suited to allow said welding wire to exit from said electrode;

- a second conveyor element suited to be connected to said main body and externally associated with said first conveyor element, said second conveyor element interacting with said first conveyor element in order to maintain said first conveyor element in the operating position when said second conveyor element is connected to said main body, wherein said at least one fume suction path is defined between said first conveyor element and said second conveyor element.

In a preferred embodiment, the second conveyor element interacts with the first conveyor element through interconnection means.

Preferably, the interconnection means comprise an element that develops according to a circular pattern and is suited to be compressed so that it interacts with the first conveyor element when the second conveyor element is connected to the main body.

According to a preferred embodiment, the interconnection means comprise a shaped filiform spring.

In a preferred embodiment, the interconnection means comprise an element that develops according to a circular pattern and is suited to be housed in at least one seat provided in the first conveyor element.

According to a preferred alternative embodiment, the second conveyor element interacts directly with the first conveyor element.

Preferably, the first conveyor element comprises an edge that projects radially outwards and the second conveyor element comprises at least one stop portion that projects radially inwards and is suited to abut the edge of the first conveyor element when the second conveyor element is connected to the main body.

In a preferred embodiment, the first conveyor element comprises at least one elastically yielding portion suited to allow the first conveyor element itself to deform radially inwards.

Preferably, said at least one elastically yielding portion comprises one or more slits.

According to a preferred embodiment, the second conveyor element is connected to the main body by means of a screwing operation or by means of a bayonet connection system.

In a preferred embodiment, the torch comprises means for automatically ejecting the first conveyor element when the second conveyor element is disconnected from the main body.

Preferably, the automatic ejection means comprise a spring.

According to a second aspect of the present invention, the same concerns a welding device comprising a power supply unit, a torch and a connection cable between said power supply unit and said torch, wherein the torch is made as described above.

In a preferred embodiment, the welding device comprises an electric power supply unit and/or a shielding gas supply unit and/or a wire feeding unit and/or a fume extraction unit and/or a cooling fluid supply unit.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages, objects and characteristic as well as further embodiments of the present invention are defined in the claims and are clarified below by means of the following description, in which reference is made to the attached drawings. In particular:

- Figure 1 shows an axonometric view of a torch in a welding device according to a preferred embodiment of the invention;

- Figure 2 shows an exploded view of the torch illustrated in Figure 1;

- Figure 3 shows the longitudinal sectional view of the torch illustrated in Figure 1;

- Figure 4 shows an enlarged detail of Figure 3;

- Figure 5 shows a sectional view of the torch along line V-V indicated in Figure 3;

- Figure 6 shows a variant embodiment of Figure 2;

- Figure 7 shows an enlarged detail of a longitudinal section of the torch of Figure 6 in the assembled configuration;

- Figure 8 shows an axonometric view of a variant embodiment of an element of the torch illustrated in Figure 2;

- Figure 9 shows an enlarged detail of a longitudinal section of a torch using the element illustrated in Figure 8;

- Figure 10 shows another variant embodiment of Figure 2;

- Figure 11 shows an enlarged detail of a longitudinal section of the torch illustrated in Figure 10 in the assembled configuration; - Figure 12 shows another variant embodiment of Figure 2;

- Figure 13 shows an axonometric view of two elements of Figure 12 connected to each other;

- Figure 14 shows one of the two elements of Figure 13;

- Figure 15 shows an enlarged detail of a longitudinal section of the torch illustrated in Figure 12 in the assembled configuration;

- Figure 16 shows another variant embodiment of Figure 2;

- Figure 17 shows an enlarged detail of a longitudinal section of the torch illustrated in Figure 16 in the assembled configuration;

- Figure 18 shows another variant embodiment of Figure 2;

- Figure 19 shows an enlarged detail of a longitudinal section of the torch illustrated in Figure 18 in the assembled configuration;

- Figure 20 shows an axonometric view of two elements of Figure 2 according to a variant embodiment of the invention;

- Figure 21 shows an element of Figure 20 from another point of view;

- Figure 22 shows an axonometric view of an element of Figure 2 according to a variant embodiment of the invention;

- Figure 23 shows a variant embodiment of Figure 22.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE PRESENT INVENTION

Although the present invention is described below with reference to its embodiments illustrated in the drawings, the present invention is not limited to the embodiments described below and illustrated in the drawings. On the contrary, the embodiments described below and illustrated in the drawings clarify certain aspects of the present invention, the scope of which is defined by the claims.

The present invention has proven to be particularly advantageous with respect to the construction of welding torches using MIG technology. However, it should be underlined that the present invention is not limited to the construction of welding torches of the said type. On the contrary, the present invention can be advantageously applied in all the cases where the use of torches for metal arc gas shielded welding is required. By way of example, the application of the present invention can be extended to MAG welding technology.

Figure 1 shows a torch according to a preferred embodiment of the invention, indicated as a whole by 10, suited to be used in a welding device 1 using MIG technology.

The welding device preferably comprises said welding torch 10, a power supply unit (not illustrated) and a cable 2 suited to connect the torch 10 to the power supply unit. The latter preferably comprises an arc current generation unit, or electric power supply unit, a shielding gas supply unit, a wire feeding and advancing unit and a suction unit. The power supply unit can also comprise a cooling fluid supply unit. The welding torch 10 according to the first preferred embodiment described with reference to Figures from 1 to 5 is a torch equipped with an air-based cooling system, the component parts of which are not described in detail herein as they are of a known type and are not part of the subject of the present invention. In some alternative embodiments described below, the torch is provided with a water-based cooling system, for example the embodiment shown in Figures 10 and 11. Also for said embodiments, the component parts of the cooling system are not described in detail as they are of a known type and are not part of the subject of the present invention.

The electric power supply unit is designed to generate the current required to produce and maintain the electric arc at the end of the welding torch 10.

The shielding gas used in MIG technology preferably comprises argon (Ar) or helium (He) or mixtures of Ar and CO2. The shielding gas supply unit comprises, for example, a pressurized gas cylinder.

The torch 10 can be used in a known manner and handled directly by an operator who holds it, or, in alternative preferred solutions, it can be used in automated stations.

The torch 10 preferably comprises a main body 12, preferably suited to be held by an operator, having an initial portion 16 provided with a bushing 17 for connection with the connection cable 2 and a terminal area 18 where the welding process is carried out.

The main body 12 preferably defines a first area 14 conveniently configured to be held by the operator and a protruding tube 15 extending towards the terminal area 18.

As explained above, the supply unit (not shown) feeds the torch 10 with the shielding gas and the welding wire.

The torch 10 serves the function of conveying the shielding gas and the welding wire towards its terminal area 18, which is conveniently arranged at the area to be welded in order to obtain the weld pool. A button 13 is preferably associated with the main body 12 and can be pressed by the operator to start the welding process.

In the terminal area 18 a first conveyor element 20, or nozzle, with its outlet mouth 20a, serves the function of directing the shielding gas towards the weld pool.

The shape of the nozzle 20 is preferably suited to convey the shielding gas in the correct direction.

In the preferred embodiment illustrated, the terminal portion of the nozzle 20 is slightly conical. In variant embodiments, however, the terminal portion may have different shapes, for example a cylindrical shape.

As shown in Figure 3, the torch 10 comprises, first of all, a current-carrying element 22 which has a preferably tubular shape and is made of an electrically conductive material, preferably copper.

The current-carrying element 22 preferably comprises a first end, not illustrated herein, suited to be connected to the electric power supply unit through the connection cable 2, and a second end 22b suited to be electrically and mechanically connected to an electrode 24 arranged inside the nozzle 20.

The electrode 24 comprises a central channel 26 suited to accommodate the welding wire (not shown) and is preferably connected to the second end 22b of the current-carrying element 22 through an electrode-holding element 28. The electrode-holding element 28 is preferably connected to the second end 22b of the current-carrying element 22 by means of a screwing operation (as shown in Figure 3).

Said connection means allow the electrode-holding element 28 to be screwed/unscrewed and thus to be easily removed. In variant embodiments, said connection means can be different, for example the connection can be obtained through mechanical interference, or it can be a snap-on (bayonet) connection, or a connection through crimping or welding. In turn, the electrode 24 is preferably connected to the electrode-holding element 28 through a screwing operation. Said connection means allow the electrode 24 to be screwed/unscrewed and thus to be easily removed. In variant embodiments, said connection means can be different, for example it is possible to provide a removable connection through mechanical interference or a snap-on (bayonet) connection. The central area 30 of the electrode-holding element 28 is hollow and preferably funnel-shaped to facilitate the introduction of the welding wire into the central channel 26 of the electrode 24.

The electrode 24 and the electrode holder 28 are made of an electrically conductive material, preferably copper, to allow the passage of the electric current from the current-carrying element 22 towards the welding wire. The wire inside the channel 26 of the electrode 24, in fact, is in contact with the electrode 24 itself. The welding wire is first moved forward inside the current-carrying element 22, then inside the central area 30 of the electrode holder 28 and then into the channel 26 of the electrode 24.

The electrode holder 28 is preferably made of copper or brass and serves to avoid screwing the electrode 24 directly onto the electrode-holding element 22 and to facilitate the assembly/disassembly and/or replacement of the electrode 24. The electrode 24, in fact, is directly in contact with the wire during the welding process and is subject to wear and overheating, and therefore periodically needs replacing.

In variant embodiments, however, the electrode could be directly connected to the current-carrying element.

Going back to the description of the main body 12, two elements 32, preferably tubular in shape, are preferably associated with the outside of the currentcarrying element 22. The inner element is preferably electrically insulating and preferably made of Teflon® while the outer element is preferably made of brass. The current-carrying element 22 in proximity to the electrode holder 28 comprises a plurality of through holes 36 defining corresponding channels suited to convey the gas from the inside of the current-carrying element 22 to the outside. In particular, the shielding gas that reaches the torch 10 in the central portion of the current-carrying element 22 is conveyed towards the outlet mouth 20a of the nozzle 20 through the holes 36.

In the embodiment illustrated, the holes 36 have a substantially circular crosssection. In different variant embodiments, however, said holes can have shapes and configurations different from those illustrated and described herein, or other different or alternative routes for conveying the gas can be defined.

As described above, the electrode-holding element 28 is connected to the second end 22b of the current-carrying element 22.

An insulating bushing 38 is preferably mounted externally to the current-carrying element 22. The bushing 38 serves as a centering element between the currentcarrying element 22 and the nozzle 20 and makes it possible to maintain the two elements 22 and 20 correctly coaxial to each other. The bushing 38 also serves as an electrically insulating element between the current-carrying element 22 and the nozzle 20.

The bushing 38 is preferably made of a rigid material with mechanical, thermal and insulating characteristics that allow it to withstand the stress generated during the welding process.

Furthermore, a sealing element 40 is preferably interposed between the bushing 38, the nozzle 20 and the tubular elements 32. At least a portion of the nozzle 20 is mounted externally to the sealing element 40.

The sealing element 40 is preferably made of a rigid material with mechanical, thermal and insulating characteristics that allow it to withstand the stress generated during the welding process, preferably brass.

The torch 20 according to the present invention is also equipped with an integrated fume extraction system. For this purpose, the terminal area 18 is advantageously provided with at least one suction path Fl suited to extract the fumes generated during the welding process.

According to an aspect of the present invention, the torch 20 comprises a second conveyor element 50, or vacuum nozzle, suited to be connected to the main body 12, more specifically to the protruding tube 15 of the main body 12.

According to the preferred embodiment shown in the figure, the vacuum nozzle 50 can be connected to the protruding tube 15 of the main body 12 by means of a bushing 15 a.

The vacuum nozzle 50 can be preferably connected to the bushing 15a by means of a screwing operation. The bushing 15a can be preferably connected to the main body 12 through mechanical interference or by allowing for a given play and with the aid of locking screws 44, as in the present embodiment.

In different variant embodiments, however, the vacuum nozzle may be connected directly to the protruding tube 15.

The vacuum nozzle 50 is associated with the outside of the nozzle 20 and the first part 52 of said fume suction path Fl is advantageously defined between the nozzle 20 and the vacuum nozzle 50, more specifically it is defined by the annular cavity 52 defined between the nozzle 20 and the vacuum nozzle 50.

The inlet through which the fumes flow into the corresponding fume suction path Fl is advantageously oriented directly towards the welding area. This makes it possible to maintain a high fume extraction efficiency, in fact the fumes are substantially extracted immediately after their generation.

The distance between the suction path/outlet Fl and the welding area is also advantageously minimized. This makes it possible to equip the welding device 1 with an extraction unit having reduced power compared to the devices of known type, where the suction mouths are further away from the welding area and require more power to maintain the desired efficiency. This results in lower manufacturing costs and reduced consumption compared to the systems of known type.

The fume suction path Fl then preferably extends towards the main body 12 of the torch 20 and is defined by an annular cavity 54 defined between the bushing 15a, the protruding tube 15 and the tubular elements 32. Finally, the fume suction path Fl extends towards the connection cable 2 to reach the extraction unit.

According to an aspect of the present invention, the vacuum nozzle 50 interacts with the nozzle 20 to maintain the nozzle 20 in the operating position when the vacuum nozzle 50 is connected to the main body 12 of the torch 10.

On the contrary, when the vacuum nozzle 50 is disconnected from the main body 12 of the torch 10 the nozzle 20 can be removed from the main body 12.

Advantageously, the operations required to replace the components of the torch 10, preferably the vacuum nozzle 50 and more preferably the nozzle 20, are simplified.

In particular, the proposed solution makes it possible to remove the vacuum nozzle 50 and the nozzle 20 from the main body 12 of the torch 10 and to replace one or both elements, if necessary. More specifically, the proposed solution makes it possible to remove and replace the nozzle 20 and/or the electrode 24, that is, the elements that are most subject to wear during the operation of the torch 10.

In the embodiment illustrated in Figures from 1 to 5, the vacuum nozzle 50 interacts with the nozzle 20, preferably through interconnection means 60, as described in detail below.

The interconnection means 60 preferably comprise an interconnection element 60.

Preferably, the interconnection element 60 comprises a spring 60 developing according to a circular configuration and shaped in such a way that it can be housed in the annular area defined between the nozzle 20 and the vacuum nozzle 50, as better illustrated in Figure 5, where the shaped spring 60 is in the normal operating position of the torch 10.

The spring 60 preferably comprises a plurality of radially external contact areas 62 suited to abut the internal surface of the vacuum nozzle 50 and a plurality of radially internal contact areas 64 suited to abut the external surface of the nozzle 20.

The spring 60 is preferably shaped in such a way that it can be radially compressed when the vacuum nozzle 50 is connected to the main body 12 of the torch 10 and, vice versa, the spring 60 can expand radially when the vacuum nozzle 50 is loosened and/or disconnected from the main body 12 of the torch 10. When the vacuum nozzle 50 is connected to the main body 12 of the torch 10, the radial compression of the spring 60 allows the nozzle 20 to be correctly maintained in the operating position thanks to the friction force generated by the external and internal contact areas 62, 64 of the spring 60.

Conversely, when the vacuum nozzle 50 is disconnected from the main body 12 of the torch 10, the radial expansion of the spring allows the nozzle 20 to be easily removed from its operating position, preferably and advantageously making it possible to carry out said replacement operations.

Furthermore, advantageously, the radial expansion of the spring occurs also when the vacuum nozzle 50 becomes loose, or is loosened, with respect to the main body 12 of the torch 10, which reduces the holding force on the nozzle 20, possibly causing the latter to be displaced or to move with respect to the operating position. This makes it possible to maintain safe conditions for the operator, preventing welding when the nozzle 20 is not in the correct operating position.

When the vacuum nozzle 50 is connected to the main body 12, the radial compression of the spring 60 is preferably achieved thanks to the action of a compression area 70 defined in the vacuum nozzle 50 and preferably comprising an internal inclined surface, more preferably a truncated cone-shaped surface, which, while the vacuum nozzle 50 is being connected/screwed onto the main body 12, compresses the spring 60 radially.

With the vacuum nozzle 50 fixed in the operating position, the spring 60 abuts the lower edge 15b of the bushing 15a, as shown in Figure 4.

The radial compression of the spring 60 is ensured by an opening 72 made along the circular pattern of the spring 60 itself, as shown in Figure 5.

The spring is preferably made from a filiform element conveniently shaped to provide the compressibility mentioned above.

The use of a filiform spring 60 also allows the passage of the welding fumes that flow through the suction path Fl. The filiform shape of the spring 60, in fact, does not prevent the passage of the fumes in the annular cavity 52 defined between the vacuum nozzle 50 and the nozzle 20, as can be seen in Figure 5.

Figures 6 and 7 show a torch 110 according to a preferred variant embodiment of the invention. The component parts equivalent to those of the first preferred embodiment described with reference to Figures from 1 to 5 are identified by the same reference numbers.

The embodiment shown in the figures differs from the embodiment described above with reference to Figures from 1 to 5 in that it includes a system for facilitating the removal of the nozzle 20 when the vacuum nozzle 50 is loosened and/or disconnected from the main body 12 of the torch 10.

For this purpose, an ejection spring 142 is preferably interposed between the sealing element 140 and the nozzle 20.

The ejection spring 142 preferably comprises a helical spring.

When the vacuum nozzle 50 is connected to the main body 12 of the torch 10, the ejection spring 142 is compressed, while the nozzle 20 is maintained in the operating position by the spring 60, as described above.

When the vacuum nozzle 50 is loosened and/or disconnected from the main body 12 of the torch 10 and the spring 60 expands releasing the nozzle 20, the ejection spring 142 pushes the nozzle 20 causing it to be automatically ejected.

Figures 8 and 9 show a variant embodiment of the interconnection means 260 between the vacuum nozzle 50 and the nozzle 20 according to the invention.

The component parts equivalent to those of the first preferred embodiment described with reference to Figures from 1 to 5 are identified by the same reference numbers.

The interconnection means 260 comprise an element that develops according to a circular pattern and can be radially expanded thanks to an opening 272 made along the circular pattern of the element 260 itself.

The interconnection element 260 preferably comprises an external contact surface 262 suited to abut the compression area 70 in the vacuum nozzle 50 (internal inclined surface 70) and a plurality of radially internal contact areas 264 suited to abut the external surface of the nozzle 20, as shown in Figure 9.

The interconnection element 260 is preferably made of steel. Figures 10 and 11 show a torch 310 according to a preferred variant embodiment of the invention. The component parts equivalent to those of the first preferred embodiment described with reference to Figures from 1 to 5 are identified by the same reference numbers.

The embodiment shown in the figures differs from the embodiment described above with reference to Figures from 1 to 5 with regard to the interconnection means 360 between the vacuum nozzle 350 and the nozzle 320.

The interconnection means 360 preferably comprise three screws 362 provided with protruding balls 366 which are pushed by thrusting means 368, preferably helical springs 368.

The screws 362 can be preferably screwed into corresponding seats provided in the vacuum nozzle 350 and the balls 366 are housed in a recessed seat 322 obtained on the external surface of the nozzle 320. Positioning the balls 366 in the recessed seat 322 maintains the nozzle 320 in the operating position.

A locking nut 364 maintains the screw 362 in place on the vacuum nozzle 350.

The nozzle 320 can be preferably removed by pulling out the nozzle 320 with such force that the balls 366 are displaced through the compression of the springs 368 that allow the balls 366 to move out of the seat 322 provided in the nozzle 320.

Figures from 12 to 15 show a torch 410 according to a preferred variant embodiment of the invention. The component parts equivalent to those of the first preferred embodiment described with reference to Figures from 1 to 5 are identified by the same reference numbers.

The embodiment shown in the figures differs from the embodiment described above with reference to Figures from 1 to 5 with regard to the interconnection means 460 between the vacuum nozzle 450 and the nozzle 420.

The interconnection means 460 preferably comprise a ring 460, better illustrated in Figure 14, comprising locking tabs 462 projecting radially inwards and suited to be housed in a recessed seat 422 created in the nozzle 420. When the vacuum nozzle 450 is connected to the main body 12 of the torch 410, the ring 460 maintains the nozzle 420 in the operating position.

When the vacuum nozzle 450 is disconnected from the main body 12 of the torch 410, the nozzle 420 with the ring 460 can be removed.

Figures 16 and 17 show a torch 510 according to a preferred variant embodiment of the invention. The component parts equivalent to those of the first preferred embodiment described with reference to Figures from 1 to 5 are identified by the same reference numbers.

The embodiment shown in the figures differs from the embodiment described above with reference to Figures from 1 to 5 with regard to the interconnection means 560 between the vacuum nozzle 550 and the nozzle 520.

The interconnection means 560 preferably comprise a ring 560 comprising locking tabs 562 projecting radially outwards and suited to be housed and locked between the vacuum nozzle 550 and the nozzle 520. The ring 560 is housed in a recessed seat 522 provided in the nozzle 520, as shown in Figure 17.

When the vacuum nozzle 50 is connected to the main body 12 of the torch 510, the ring 560 maintains the nozzle 520 in the operating position.

When the vacuum nozzle 550 is disconnected from the main body 12 of the torch 510, the nozzle 520 with the ring 560 can be removed.

Figures 18 and 19 show a torch 610 according to a preferred variant embodiment of the invention. The component parts equivalent to those of the first preferred embodiment described with reference to Figures from 1 to 5 are identified by the same reference numbers.

The embodiment shown in the figures differs from the embodiments described above in that the vacuum nozzle 650 interacts directly with the nozzle 620 to maintain the nozzle 620 in the operating position, that is, without the use of further interconnection means such as, for example, those illustrated and described with reference to the previous embodiments.

The nozzle 620 is preferably provided with an edge 622 projecting radially outwards.

The vacuum nozzle 650 comprises at least one stop portion 652 that projects radially inwards, as shown in Figure 19. When the vacuum nozzle 650 is connected to the main body 12 of the torch 610, the stop portion 652 of the vacuum nozzle 650 abuts the projecting edge 622 of the nozzle 620 while maintaining the nozzle 620 in the operating position.

When the vacuum nozzle 650 is disconnected from the main body 12 of the torch 610, the nozzle 620 can be removed.

Figures 20 and 21 show a possible variant embodiment with regard to the type of connection of the vacuum nozzle 750 to the bushing 715a of the main body of the torch. According to said embodiment, the vacuum nozzle 750 can be connected to the bushing 715a by means of a bayonet connection instead of by means of a screwing operation as described and illustrated above.

The vacuum nozzle 750 preferably comprises a pin 752 projecting radially inwards and suited to be fitted into a corresponding external channel 720 created on the external surface of the bushing 715a.

Figures 22 and 23 show two possible variant embodiments of the nozzle 820, 920 according to the invention.

Said embodiments differ from the embodiment described above with reference to Figures from 1 to 5 in that the upper portion of the nozzle 820, 920 that comes into contact with the internal contact areas 64 of the spring 60 is made elastically yielding, preferably by means of one or more axial slits 822 (Figure 22) or a helical slit 922 (Figure 23).

In the assembled configuration of the torch, therefore, the upper portion of the nozzle 820, 920 yields elastically under the action of the spring 60 and deforms in a radial inward direction, thus increasing the sealing force towards the sealing element 40 on which the nozzle is mounted.

It has thus been shown, by means of the above description, that the torch according to the present invention allows the set objects to be achieved. In particular, the torch according to the present invention makes it possible to improve the extraction efficiency and/or to simplify the maintenance and/or replacement of the consumable elements.

Although the present invention has been clarified above by means of the detailed description of its embodiments illustrated in the drawings, the present invention is not limited to the embodiments described above and illustrated in the drawings; on the contrary, further variants of the embodiments described herein fall within the scope of the present invention, which is defined by the claims.

Claims

1) Welding torch (10; 110; 310; 410; 510; 610) with integrated fume extraction system, said torch (10; 110; 310; 410; 510; 610) comprising a main body (12) and a terminal area (18) suited to be fed, through said main body (12), with a welding wire and a welding shielding gas, said terminal area (18) being provided with at least one fume suction path (Fl) suited to extract the fumes generated during the welding process, characterized in that said terminal area (18) comprises:

- an electrode (24) suited to be powered electrically and provided with an internal channel (26) for the passage of said welding wire;

- a first conveyor element (20; 320; 420; 520; 620; 820; 920) externally associated with said electrode (24) and suited to allow said shielding gas to be conveyed outside said electrode (24), said first conveyor element (20; 320; 420; 520; 620; 820; 920) being provided with an outlet mouth (20a) suited to allow said welding wire to exit from said electrode (24);

- a second conveyor element (50; 350; 450; 550; 650) suited to be connected to said main body (12) and externally associated with said first conveyor element (20; 320; 420; 520; 620; 820; 920), said second conveyor element (50; 350; 450; 550; 650) interacting with said first conveyor element (20; 320; 420; 520; 620; 820; 920) in order to maintain said first conveyor element (20; 320; 420; 520; 620; 820; 920) in the operating position when said second conveyor element (50; 350; 450; 550; 650) is connected to said main body (12), wherein said at least one fume suction path (Fl) is defined between said first conveyor element (20; 320; 420; 520; 620; 820; 920) and said second conveyor element (50; 350; 450; 550; 650).

2) Torch (10; 110; 310; 410; 510) according to claim 1, characterized in that said second conveyor element (50; 350; 450; 550; 450) interacts with said first conveyor element (20; 320; 420; 520; 820; 920) through interconnection means (60; 260; 360; 460; 560).

3) Torch (10; 110) according to claim 2, characterized in that said interconnection means (60; 260) comprise an element which is configured according to a circular pattern and is suited to be compressed so that it interacts with said first conveyor element (20) when said second conveyor element (50) is connected to said main body (12).

4) Torch (10; 110) according to claim 3, characterized in that said interconnection means (60) comprise a shaped filiform spring (60).

5) Torch according to claim 2, characterized in that said interconnection means (460) comprise an element (460) which is configured according to a circular pattern and is suited to be housed in at least one seat (422) provided in said first conveyor element (420).

6) Torch (610) according to claim 1, characterized in that said second conveyor element (650) interacts directly with said first conveyor element (620).

7) Torch (610) according to claim 6, characterized in that said first conveyor element (620) comprises an edge (622) that projects radially outwards and said second conveyor element (650) comprises at least one stop portion (652) that projects radially inwards and is suited to rest against said edge (622) of said first conveyor element (620) when said second conveyor element (650) is connected to said main body (12).

8) Torch according to any of the preceding claims, characterized in that said first conveyor element (820; 920) comprises at least one elastically yielding portion suited to allow said first conveyor element (820; 920) to be radially deformed towards the inside.

9) Torch according to claim 8, characterized in that said at least one elastically yielding portion comprises one or more slits (822; 922).

10) Torch (10; 110; 310; 410; 510; 610) according to any of the preceding claims, characterized in that said second conveyor element (50; 350; 450; 550; 650) is connected to said main body (12) through a screwing operation or through a bayonet connection system.

11) Torch (110) according to any of the preceding claims, characterized in that it comprises automatic ejection means (142) suited to eject said first conveyor element (20) when said second conveyor element (50) is disconnected from said main body (12).

12) Torch (10; 110; 310; 410; 510; 610) according to claim 11, characterized in that said automatic ejection means (142) comprise a spring (142).

13) Welding device (1) comprising a power supply unit, a torch (10; 110; 310; 410; 510; 610) and a connection cable (2) between said power supply unit and said torch (10; 110; 310; 410; 510; 610), characterized in that said torch (10; 110; 310; 410; 510; 610) is made according to any of the preceding claims.

14) Device (1) according to claim 13, characterized in that it comprises a power supply unit and/or a shielding gas supply unit and/or a feeding unit suited to feed 18 the wire and move it forward and/or a fume extraction unit and/or a cooling fluid supply unit.