STORAGE AND FEEDING ASSEMBLY FOR A WELDING WIRE FOR A WELDING OR BRAZING PLANT

A storage and feeding assembly for a wire to be fed to an apparatus having a drum suitable for storing the wire and extending about a drum axis between a resting base and an open upper end is provided. A wire handling device positioned between the drum and the apparatus is suitable for extracting the wire from the drum to feed the wire to the apparatus. A lid is placed above the drum and an outlet passage for the wire is provided at a top of the lid. The storage and feeding assembly has a spacer suitable for being positioned in a releasable manner between the upper end of the drum and the lid in such a way as to act as an extension for the drum.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Italian Patent Application No. 102023000018489 filed Sep. 8, 2023, the contents of which is hereby incorporated in its entirety by reference.

FIELD OF THE INVENTION

The present invention relates to the field of wire welding or brazing plants and in particular to a storage and feeding assembly for a welding wire for welding or brazing plants.

The present invention may however be used for any type of wire that has to be stored in a drum and supplied to a plant positioned downstream of the assembly.

BACKGROUND OF THE INVENTION

As is known, some welding or brazing plants use a welding wire stored in a drum. The wire is progressively extracted from the drum and supplied to the welding apparatus, for example a welding torch moved either by a robot or manually.

An example of a storage and feeding assembly typical of the prior art is shown inFIG.1, wherein a welding wire wound in coils is stored in a cylindrical drum closed by a conical lid. The conical lid, which has a wire outlet passage at the top thereof, also has the function of guiding the wire towards the outlet passage in such a way as to limit the formation of kinks. The wire is pulled out of the drum and fed to the welding apparatus by a wire pulling device. In some embodiments, for example of the type described in WO2018167806A1, in the name of the instant Applicant, the wire pulling device is also associated with a wire straightening device that is suitable for eliminating, or at least reducing, the tendency of the wire to twist due to the prolonged storage thereof in the form of coils in the drum.

In the known solutions, typically, the bundle of wire does not occupy all the available volume of the drum, due both to the requirement to position, at the top of the bundle of wire, unwinding accessories to facilitate unwinding the wire towards the exit passage, and also to avoid forcing the wire to complete an overly pronounced curve upwards (exit angle a inFIG.1), that may facilitate the formation of kinks in unwinding the wire.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a storage and feeding assembly for a wire, wound in a coil, in a drum that makes it possible to store a greater quantity of wire in the drum, thus reducing the drum replacement frequency and increasing productivity.

Said object is achieved by a storage and feeding assembly as described and claimed herein. Preferred embodiments of the present invention are also described.

DETAILED DESCRIPTION

In the drawings, reference numeral 1 has been used to denote, as a whole, a storage and feeding assembly for a welding wire to be supplied to an apparatus, such as a welding torch, according to the present invention. The storage and feeding assembly1extends along an assembly axis X-X.

According to the present invention, the storage and feeding assembly1comprises a drum2, for example cylindrical in shape or with a polygonal cross section, that is suitable for storing a welding wire10wound in coils10′, forming a bundle12of wire. In particular, the coils10′ of the wire10are maintained in an ordered overlapping relationship that allows the correct extraction of the welding wire10from the drum2.

The drum extends about a drum axis Y-Y between a resting base21and an

open upper end23.

Preferably, the assembly axis X-X and the drum axis Y-Y are aligned.

The ratio between a longitudinal dimension of the drum2and a longitudinal dimension of the bundle12is between 70% and 100%, preferably 85%.

The term “longitudinal dimension” refers to the dimension along the drum axis Y-Y.

Furthermore, the storage and feeding assembly1comprises a wire handling device3positioned between the drum2and the apparatus and suitable for extracting the wire from the drum2in order to feed it to the welding or brazing apparatus (not shown).

According to one embodiment (shown inFIGS.7,8aand8b), the wire handling device3comprises a wire straightening group50and/or a wire pulling group60.

The wire pulling group60comprises two opposing driving belts12,12′. The two driving belts form two respective straight belt segments14facing each other so as to receive therebetween and move the wire10exiting from the drum2.

In other words, each driving belt12;12′ is returned by respective tensile rollers13;13′ in such a way as to form a closed ring. One of the tensile rollers13,13′ is a drive roller suitable for generating the rotation of the respective driving belt12;12′.

In one embodiment, the drive roller is keyed to a shaft of an actuator17, for example a pneumatic or electric actuator.

In one embodiment, each driving belt12;12′ is returned on three tensile rollers13;13′.

In one embodiment, the extension of the straight segment14is at least equal to the diameter of the tensile rollers13;13′, i.e., it is on the order of tens or, preferably, hundreds of mm.

In fact, with respect to the driving rollers of the prior art, which, having

punctual contact with the welding wire, exert a high specific pressure on the wire, the driving belts12;12′, having a much larger contact surface with the wire than the rollers, exert a much lower specific pressure.

The welding wire10is therefore not deformed by the passage between the driving belts12;12′, and also any deposit of dust or other external agents on the belts has no effect on the surface of the wire.

Furthermore, handling of the wire without deformation or alteration effects on the wire is facilitated by the fact that the driving belts12;12′ may be made of a softer material than the one with which the driving rollers are usually made.

In one embodiment, the tensile rollers13;13′ of the two opposite driving belts12;12′ are supported by respective driving plates120;120′ that may be mutually spaced apart, for example by micrometric screws122, as a function of the diameter of the welding wire10.

According to a further embodiment (not shown), the wire pulling group60comprises a plurality of motorized wire pulling rollers facing each other so as to receive therebetween and move the wire10exiting from the drum2. Preferably, there are two or four wire pulling rollers.

The wire straightening group50, which as mentioned hereinabove may be positioned downstream or upstream of the wire pulling group60, comprises at least two roller straightening units52,52aarranged in series with each other along the advancement direction of the wire. Each straightening unit52;52acomprises at least two opposing straightening rollers54,54′;54a,54a′ between which the welding wire10is made to pass, being moved by the wire pulling group60.

The straightening rollers54,54′ of one straightening unit52are oriented perpendicular to the straightening rollers54a,54a′of at least one other straightening unit52a.However, all of the straightening rollers54,54′;54a,54a′have the respective rotation axes thereof perpendicular to the advancement direction of the welding wire10, i.e., perpendicular to the straight segments14of the driving belts12,12′.

With such an arrangement of the straightening rollers, it has been experimentally verified that the memory of the welding wire10emerging from the drum2is completely eliminated. The welding wire10that emerges from the wire straightening group50is therefore completely neutral.

In one embodiment the straightening rollers54,54′;54a,54a′are mounted idly on a respective roller support plate56,56a.Therefore, the straightening rollers effectively perform only the function of straightening the welding wire10. By not exerting any torque on the wire, the wire is straightened, but the cross section thereof is not deformed nor is the surface thereof altered.

According to one embodiment, each roller straightening unit52,52ais provided with at least five straightening rollers54,54′;54a,54a′:at least two first rollers54;54aarranged side by side along the advancement direction of the wire, opposite and offset with respect to at least three second rollers54′;54a′arranged side by side along the advancement direction of the wire.

In one embodiment, the straightening rollers of each straightening unit are seven in number: three first rollers54;54aarranged side by side along the advancement direction of the wire, opposite and offset with respect to four second rollers54′;54a′arranged side by side along the advancement direction of the wire.

In one embodiment, also the distance between the first and second straightening rollers54,54′;54a,54a′may be adjusted as a function of the diameter of the necessary deformation of the welding wire10.

The storage and feeding assembly1comprises a substantially conical lid5in which an outlet passage5′ for the wire10is provided at the top of the lid.

According to one embodiment, the lid side wall55is at least partially made of a transparent material in such a way as to allow for visual inspection of the handling device3through the lid side wall.

According to one embodiment, the lid side wall55is entirely made of a transparent material. Preferably, the entire lid5is made of a transparent material.

According to one embodiment, the lid5is made of a plastics material.

According to the present invention, the storage and feeding assembly1comprises a spacer4suitable for being releasably positioned between the upper end23of the drum2and the lid5.

The spacer comprises a spacer body40that defines a spacer housing400delimited by an annular side wall42in such a way as to act as an extension for the drum2.

According to one embodiment, the annular side wall42is at least partially made of a transparent material in such a way as to allow for a visual inspection of the spacer housing400through the annular side wall42.

According to one embodiment, the annular side wall42is entirely made of a transparent material. Preferably, the entire spacer body40is made of a transparent material.

According to one preferred embodiment, the spacer body40is made of a plastics material.

According to one embodiment, the spacer4is placed at the end of the drum2. Preferably, a spacer outlet opening4′ is provided in the spacer4through which the wire10originating from the drum2emerges.

According to one embodiment, the spacer body40further comprises an upper base44connected to the annular side wall42. In other words, the annular side wall42and the upper base44define the spacer housing400. Preferably, the spacer outlet opening4′ is provided in the upper base44.

According to one embodiment, the wire handling device3is integrally fastened to the upper base44, in particular externally with respect to the spacer housing400.

According to one embodiment, the wire handling device3is screwable to the spacer4, preferably to the upper base44.

According to a further embodiment, the wire handling device3comprises a support base30suitable for supportingly engaging and being fastened to the spacer4, preferably to the upper base44.

FIG.3schematically shows the storage and feeding assembly1wherein the welding wire10of the upper coil, emerging from the drum outlet opening2′, passes through the spacer housing400and exits from the spacer outlet opening4′, preferably provided in the upper base44, and is engaged by the wire handling device3.

According to one embodiment, the annular side wall42comprises plate-shaped elements42aand vertical supports42binterposed therebetween.

According to one embodiment, in the annular side wall42, preferably in the

plate-shaped elements42a,spacer openings42′ are provided for accessing the spacer housing400when the spacer4engages the drum2. Preferably, such openings42′ may be opened and closed by a door42″.

According to one embodiment, the door42″ is made of a transparent material. According to one embodiment, the annular side wall42has an adjustable axial

extension. “Axial extension” means along the assembly axis X-X. Preferably, the annular side wall42is adjustable; for example, it is a telescopic wall.

According to one embodiment, the spacer body40comprises a lower flange46for the engagement with the drum2. In particular, the lower flange46rests against an upper edge20of the drum2.

According to one embodiment, the annular side wall42, preferably the vertical supports42b,comprises upper longitudinal holes48′ and lower longitudinal holes48″ for the engagement, by means of screws49, with the upper base44and the lower flange46respectively. In other words, there is a mutual mechanical engagement between the annular side wall42and the upper base44, and between the annular side wall42and the lower flange46.

According to one embodiment, the storage and feeding assembly1comprises first coupling means15for releasably coupling the spacer4to the drum2. Preferably, the first coupling means15comprise a first releasable clamping ring16that couples adjacent end portions of the drum2and of the annular side wall42. Preferably, the first clamping ring16has a C-shaped cross section.

According to one embodiment, the first clamping ring16comprises first handling means160suitable for configuring the first clamping ring16from an open configuration to a closed configuration wherein it engages the adjacent end portions of the drum2and of the annular side wall42in order to fasten them in a stable manner to each other.

According to one embodiment, a lower end portion of the annular side wall42comprises a lower circumferential groove14for engagement with the first clamping ring16. Preferably, the lower circumferential groove14is provided only at the vertical supports42b.

According to one embodiment, the upper end23of the drum2comprises a

circumferential drum groove22for engagement with the first clamping ring16.

According to one embodiment, the first clamping ring16is partially inserted into the lower circumferential groove14of the annular side wall42, and into the circumferential drum groove22of the drum2.

According to one embodiment, the lid5, positioned on the spacer4, preferably on the upper base44, defines a lid volume500.

According to one embodiment, the lid5comprises an upper lid wall50in which the outlet passage5′ is provided, and a lid side wall55.

According to one embodiment, the handling device3extends into the lid volume500substantially coaxially to the drum axis Y-Y.

In a further embodiment (not shown), the wire handling device3is positioned downstream of the lid5along the wire feed direction to the apparatus. In other words, the wire handling device3is positioned externally to the lid5, it is, for example, integrally fastened to the upper lid wall50, externally in relation to the lid volume500.

According to one embodiment, lid openings55′ are provided in the lid side wall55to access the lid volume500when the lid5engages with the spacer4. Preferably, the openings55′ may be opened and closed by a door55″.

According to one embodiment, the door55″ is made of a transparent material.

According to one embodiment, the storage and feeding assembly1comprises second coupling means25for coupling the lid5to the spacer4. Preferably, the second coupling means25comprise a second releasable clamping ring26that couples adjacent end portions of the annular side wall42and of the lid5. Preferably, the second clamping ring26has a C-shaped cross section.

According to one embodiment, the second clamping ring26comprises second handling means260that are suitable for configuring the second clamping ring26from an open configuration to a closed configuration wherein it engages the adjacent end portions of the annular side wall42and of the lid5in order to fasten them in a stable manner to each other.

According to one embodiment, an upper end portion of the spacer body40comprises an upper circumferential groove24for engagement with the second clamping ring26. Preferably, the upper circumferential groove24is provided only at the vertical supports42b.

According to one embodiment, the second clamping ring26engages the annular side wall42, preferably the vertical supports42band the lid5, preferably the lid side wall55.

According to one embodiment, the second clamping ring26is partially

inserted into the upper circumferential groove24of the annular side wall42.

According to one embodiment, the storage and feeding assembly1comprises at least one wire end sensor, which may be positioned, with respect to the wire supply direction, downstream and/or upstream of the wire handling device3.

In particular, in the embodiment wherein the wire handling device3comprises the wire straightening group and the wire pulling group, the at least one wire end sensor may be positioned between the wire straightening group and the wire pulling group, or before and/or after each of the wire straightening group and the wire pulling group.

According to one embodiment (shown schematically inFIGS.6a,6b,6c,6dand6e), the storage and feeding assembly1comprises at least one wire unwinding accessory100positioned at least partially in the spacer housing400.

For example, the accessory100is a wire guide device110(FIG.6d), also known in the jargon as a “pay-off system,” which allows the welding wire10to exit the drum2correctly. Such wire guide device generally has a conical shape and comprises a base that rests above the coils10′ of the wire and a rotating tubular element which guides the wire of the upper coil towards the drum outlet opening2′.

FIG.1schematically shows the storage and feeding assembly typical of the prior art, wherein the lid is directly engaged with the drum, and the wire handling device is external to the lid. In particular, the welding wire originating from the upper coil, towards the wire handling device, forms an angle a with a transverse axis with respect to the assembly axis.

FIG.3shows, on the other hand, the storage and feeding assembly1of the present invention which comprises the spacer4, placed between the drum2and the lid5, and wherein the wire handling device3is preferably inserted inside the lid5. In particular, the welding wire10originating from the upper coil towards the wire handling device3forms an angle ß with a transverse axis with respect to the assembly axis X-X. Such angle β is greater than the angle α, thus in the storage and feeding assembly of the present invention, the wire has a lower possibility of tangling and deformation than the wire of the storage and feeding assembly of the prior art.

In other words, using the spacer allows a greater angle of exit of the wire from the drum, thus decreasing the tangling and deformation of the wire.

The upper base of the spacer, to which the wire handling device is fastened, prevents debris, such as dust, from entering the drum thereby damaging the stored wire.

The use of the lid makes it possible to protect the wire handling device furthermore preventing the operator from being exposed to accidental injury, such as injury caused by electric shock due to unwanted voltage losses.

The openings in the spacer and in the lid may be secured in such a way that only specialized personnel may have access thereto, thereby avoiding tampering and/or accidental injury by the operators.

A person skilled in the art may make changes or replacements of elements with other functionally equivalent ones in the embodiments of the storage and feeding assembly in order to meet specific needs. These variants are also contained within the scope of protection as defined by the following claims. Moreover, each variant described as belonging to a possible embodiment may be implemented independently of the other variants described.