Technical Field

The present invention relates to a cutting machine with increased productivity for manufacturing wire-like rods, particularly for the production of rod-like electrodes for welding.

Background art

Among the methods for the production of rod-like electrodes for welding, it is known to use cutting machines that are adapted to cut a wirelike product into rods of standardized lengths, equal for example to 350 millimeters, 400 millimeters and 450 millimeters and with a diameter comprised between 2 and 5 millimeters.

These known types of cutting machine comprise an advancement assembly, generally of the type with pairs of motorized rollers with parallel and mutually opposite rotation axes, in which the wire-like product is picked up sequentially by each pair of rollers and pushed toward the next pair of rollers.

More precisely, the rollers of the motorized assembly have circumferential grooves of suitable diameter in which the wire-like product is accommodated.

In this manner, the wire-like product acquires speed and is pushed into a straightening assembly, which is composed of two series of free rollers with axes of rotation that are parallel and alternated between the two different series.

The wire-like product then enters a cutting assembly constituted by a pair of rotating shears which cut the wire-like product into rods.

More precisely, the rotating shears are implemented by a pair of motorized rollers with parallel and mutually opposite axes of rotation which are in contact with the wire-like product, each provided with a blade arranged on the outer side wall of each roller.

As a consequence of the advancement of the wire-like product, since the latter is in tangential contact with the two motorized rollers of the rotating shears, it is cut to a length that is equal to the circumference of the roller that supports the blade.

The cut portions of wire-like product are then picked up by an acceleration assembly with slotted belts for expelling the individual portion from the cutting assembly and for sending said portion into a box-like body that has a stop surface against which the portions abut so as to subsequently fall onto a cross-like member, which by rotating about itself makes the portions of wire-like product fall into an adapted underlying container.

These known types of cutting machines are not devoid of drawbacks, which include the fact that once the rotating shears of the cutting assembly and the rollers of the advancement assembly have been defined it is possible to obtain only one rod format.

In other words, this means that every time the rod format changes it is necessary to change the rotating shears.

This leads to inevitable machine downtimes every time the format is changed, both in the case of a change of format in terms of length and in terms of diameter, and to large quantities of equipment to store in order to allow the provision of the entire production range.

Another drawback of conventional cutting machine resides in that, since there is no direct detection of the advancement speed of the wire-like product, any slippages of the pusher rollers cause inaccuracy in the final length of the resulting rods.

A further drawback of conventional cutting machines consists in that the rods are collected in a container haphazardly and this can lead to non- optimization of the loading volume of said container.

Disclosure of the invention

The aim of the present invention is to provide a cutting machine with increased productivity for manufacturing wire-like rods, particularly for the production of rod-like electrodes for welding, which is capable of adapting to any type of format of the rods to be obtained, minimizing machine downtimes and the quantity of equipment in store.

Within this aim, an object of the present invention is to provide a cutting machine that can provide rods of wire-like products while ensuring high cutting precision and therefore high precision of the lengths of said rods.

Another object of the present invention is to provide a cutting machine that is provided with a device capable of optimizing the loading volume of the container in which the final product is deposited.

A further object of the present invention is to provide a cutting machine that is capable of ensuring highest reliability and safety of use.

Another object of the invention is to provide a cutting machine that is easy to provide and economically competitive in comparison to the background art.

This aim, as well as these and other objects that will become better apparent hereinafter, are achieved by a cutting machine with increased productivity for manufacturing wire-like rods, particularly for the production of rod-like electrodes for welding, comprising at least one advancement assembly adapted to receive and produce the advancement of a wire-like product at a preset advancement speed from an inlet of said cutting machine to at least one cutting assembly, which is adapted to cut said wirelike product into rods of preset lengths, said at least one cutting assembly being interposed, along the advancement line of said wire-like product and of said rods, between said at least one advancement assembly and at least one assembly for collecting said rods for storing them, characterized in that said cutting assembly comprises at least two rotating shears of the motorized type with rotation axes which are parallel and mutually opposite with respect to the advancement line of said wire-like product, synchronization means being further comprised which are associated with said at least one cutting assembly and with said at least one advancement assembly for the adjustment of the tangential speed of said rotating shears and of said rods as a function of said advancement speed of said wire-like product in output from said at least one advancement assembly.

Brief description of the drawings

Further characteristics and advantages will become better apparent from the description of a preferred but not exclusive embodiment of a cutting machine with increased productivity for manufacturing wire-like rods, particularly for the production of rod-like electrodes for welding, illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figure 1 is a schematic side elevation view of a preferred embodiment of a cutting machine according to the invention;

Figure 2 is a schematic rear elevation view of the cutting machine shown in Figure 1 ;

Figure 3 is a schematic front elevation view of the cutting machine shown in Figure 1.

Ways of carrying out the invention

With reference to the figures, the cutting machine with increased productivity for manufacturing wire-like rods, particularly for the production of rod-like electrodes for welding, generally designated by the reference 1, comprises a supporting frame 2, on which at least one advancement assembly 3 is installed which is adapted to receive and produce the advancement of a wire-like product 4 at a preset advancement speed from an inlet 5 of the cutting machine 1 to at least one cutting assembly 6, which is adapted to cut the wire-like product 4 into rods 7 of preset lengths.

More precisely, the advancement assembly 3 is of the type with pairs of motorized rollers 8 with rotation axes 8a which are parallel and mutually opposite with respect to the advancement line of the wire-like product 4. The motorized rollers 8 are turned about their own rotation axes 8a by means of a suitable belt transmission 9 and 10 that connects them to an electric motor 11.

Moreover, each motorized roller 8 of the advancement assembly 3 has at least one circumferential groove 12 that has a substantially semicircular profile so as to define, with the corresponding motorized roller 8, a channel

13 for the passage of the wire-like product 4.

In this manner, the wire-like product 4 is gripped between the two circumferential grooves 12 of two motorized rollers 8 that face each other and advances with an advancement speed that is substantially equal to the tangential speed of the motorized rollers 8 of the advancement assembly 3.

Advantageously, as shown in Figure 2, in order to allow the machine 1 to be able to operate with wire-like products having different diameters without the necessity of changing parts thereof, for each pair of pluralities of motorized rollers 8 there is a plurality of passage channels 13 with different diameters.

The cutting assembly 6, according to the invention, comprises at least two rotating shears 14 of the motorized type, which are constituted by two drums, each of which supports a blade 18, and which have rotation axes 14a that are parallel and mutually opposite with respect to the advancement line of the wire-like product 4.

Also according to the invention, synchronization means 15 are provided which are associated with the cutting assembly 6 and with the advancement assembly 3 to adjust the tangential speed of the rotating shears

14 and of the rods 7 as a function of the advancement speed of the wire-like product 4 that exits from the advancement assembly 3.

More specifically, the synchronization means 15 comprise at least one pair of free rollers 16, which are arranged at the outlet of the advancement assembly 3, with their rotation axes 16a parallel and mutually opposite with respect to the advancement line of the wire-like product 4, and are provided with angular position transducers, such as for example encoders of the absolute or of the relative type, which are functionally connected to the rotating shears 14 by way of means 17 for the electronic management of the rotation rate of the rotating shears 14 and therefore of the rods 7.

More particularly, the free rollers 16, which also have circumferential grooves that correspond to the circumferential grooves 12 of the motorized rollers 8, are in tangential contact with the wire-like product 4, so as to rotate about their own rotation axes 16a as a consequence of the tangential thrust imparted by friction by the wire-like product 4.

Moreover, at least one straightening assembly 19, which is per se known and therefore not described in detail, is interposed between the advancement assembly 3 and the cutting assembly 6 in order to straighten the wire-like product 4 that exits from the advancement assembly 3.

Finally, in output from the cutting assembly 6, along the advancement line of the wire-like product 4 and of the rods 7, at least one assembly 20 for collecting the rods 7 for their storage is provided.

More precisely, the collecting assembly 20 comprises a conveyor element 21 which is arranged in output to the cutting assembly 6 and leads into at least one collection tray 22 of the rods 7.

Advantageously, the conveyor element 21 comprises a tubular body 23 that is substantially rectilinear and inclined from an inlet 24 of the rods 7 to an outlet 25 of the rods 7 downward, so as to utilize the force of gravity to deposit the rods 7 in the collection tray 22.

Advantageously, means 26 are provided for distributing the rods 7 in output from the conveyor 21 for their tidy and uniform collection in the collection tray 22.

Such distribution means, as shown in Figure 3, comprise an oscillating arm 27 that can move transversely to the advancement direction of the rods 7 in output from the conveyor element 21 about a pivoting axis 27a and comprises a discharge duct 28 that has a converging transverse cross- section and is provided with one or more pairs of motorized expulsion rollers 29 with rotation axes 29a which are parallel and mutually opposite with respect to the direction of the falling of the rods 7 into the collection tray 22.

Moreover, in order to achieve an even more uniform and optimum filling of the collection tray 22, means 30 are provided for adjusting the inclination of the tubular body 23 with respect to the output direction of the rods 7 from the cutting assembly 6, which consist for example of a hydraulic piston 31 interposed between the supporting frame 2 and the tubular body 23.

Operation of the cutting machine 1 with increased productivity for the production of wire-like rods, particularly for the production of rod-like electrodes for welding, is described hereinafter.

Depending on the diameter of the wire-like product 4 to be cut, it is inserted in an adapted passage channel 13 so that the motorized rollers 8 of the advancement assembly 3 can produce the advancement, with an optimum advancement speed, of the wire-like product 4 within the cutting machine 1.

In output from the advancement assembly 6, the angular position transducers applied to the free rollers 16 detect the speed of the wire-like product 4, adjusting, by way of the electronic management means 17, the rotation rate of the rotating shears 14.

Advantageously, the tangential speed of the rotating shears 14 and therefore the advancement speed of the rods 7 in output from the cutting assembly 6 is higher than the advancement speed of the wire-like product 4, so as to allow the separation and launching of the rods 7 into the conveyor element 21 , which by way of the distribution means 26 are collected in a tidy and uniform manner in the collecting tray 22.

In practice it has been found that the cutting machine with increased productivity for manufacturing wire-like rods, particularly for the production of rod-like electrodes for welding, according to the present invention, fully achieves the intended aim and objects, since it allows passing from one format of the finished product, in terms of length and in terms of diameter, to the other without the necessity of replacing any component and therefore without any machine downtime.

Another advantage of the cutting machine according to the present invention consists in that it ensures high precision also in all operating transients.

A further advantage of the cutting machine according to the present invention consists in that it is economically competitive if compared to the background art.

The cutting machine with increased productivity for manufacturing wire-like rods, particularly for the production of rod-like electrodes for welding, thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims.

All the details may further be replaced with other technically equivalent elements.

In practice, the materials used, as long as they are compatible with the specific use, as well as the contingent shapes and dimensions, may be any according to requirements.

The disclosures in Italian Patent Application No. MI2011A000217 from which this application claims priority are incorporated herein by reference.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.