WO2018189762A1

WO2018189762A1 - Labelling apparatus and method for metal products

Info

Publication number: WO2018189762A1
Application number: PCT/IT2018/050063
Authority: WO
Inventors: Gianfranco D'ORLANDO
Original assignee: Alping Italia Srl
Current assignee: Alping Italia Srl
Priority date: 2017-04-12
Filing date: 2018-04-12
Publication date: 2018-10-18
Anticipated expiration: 2019-10-12
Also published as: IT201700040964A1; EP3609793A1; WO2018189762A4

Abstract

Apparatus (10) and method for labelling metal products (1 1), comprising a supply unit (17) to supply a label (13), a robot (18) at least partly mobile provided with a welding head (20) configured to weld to the metal product (1 1) at least a support pin (14) of the label (13), wherein the apparatus (10) comprises a feed unit (19) to feed the pin (14) and a conveyor pipe (40) connecting the feed unit (19) to the welding head (20) in order to deliver the pin (14) directly into the welding head (20). The invention also concerns the welding head (20), the pin (14) used and the feed unit (19).

Description

"LABELING APPARATUS AND METHOD FOR METAL PRODUCTS"

FIELD OF THE INVENTION

The present invention concerns a labeling apparatus for metal products such as billets, bars, slabs, or other metal products, both hot and cold. In the following description the products are identified as metal products.

Formulations of the present invention also concern a labeling method used to integrate a label, or a tag, with the corresponding oblong metal product.

The present invention also concerns a pin loading unit, a welding head, a pin used to constrain the label to the metal product and a label supply unit.

BACKGROUND OF THE INVENTION

The need to trace metal products obtained by iron and steel plants is known, associating with each of them a specific distinctive label to supply specific information relating to each single oblong metal product.

The implementation of labeling in the iron and steel industry has many problems, such as the variability of the surfaces of the metal products, the high level of dirt, the presence of oxidized portions, the high working temperatures, which do not allow to provide a robust, fast and efficient solution.

There is an increasingly felt need to speed up and optimize the product labeling steps, to respond to the increasingly high production rates and reduce costs.

Some known techniques provide to integrate the labels with the metal product by means of the "pick and place" technique, that is, by picking and positioning, on each occasion and for each oblong metal product, the elements necessary for the labeling process. The "pick and place" technique provides to pick, on each occasion, a cylindrical pin from a pin delivery station, to insert the pin picked into a hole on the specific printed label, and to position the assembly consisting of the pin and the label on the head surface of the metal product to be labeled. Subsequently, the pin is welded to the metal product and the label clamped to the pin by a retaining element, such as a metal disk, or a clip.

It is quite clear that this known solution requires many complex manipulations that require long times and high costs that are no longer acceptable in relation to the competitive regimens of the sector. Moreover, due to the high number of manipulations, errors may occur, or uncertain labeling that normally entails slowdowns, or interruptions to production.

The "pick and place" technique also entails a considerable consumption of energy, since it requires many repeated picking and positioning manipulations for each of the metal products to be labeled.

There is therefore a need to perfect and make available an apparatus and a method for labeling metal products, which overcome at least one of the disadvantages of the state of the art.

There is also a need to perfect and make available a pin feed unit, a welding head and a pin, to label the metal products, which overcome at least one of the disadvantages of the state of the art.

It is also necessary to perfect and make available a label supply unit which overcomes at least one of the disadvantages of the state of the art.

One purpose of the present invention is to provide a labeling apparatus, and a connected method, that allows to obtain labeled metal products rapidly and with a limited consumption of energy.

Another purpose is to provide a pin feed unit which allows to rapidly supply the pins to be associated with the label on each occasion.

Another purpose is to make available a label supply unit able to simplify the operations to pick up the label in order to quickly guarantee a sure association between pin and label.

Another purpose is to provide a welding head able to associate the assembly consisting of the pin and the label with the metal product in a reliable and error- free manner.

Another purpose is to provide a pin to be associated with the label able to obtain a sure labeling which does not require additional retaining elements.

The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claims, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea. In accordance with the above purpose, an apparatus for labeling metal products according to the present invention comprises a supply unit to supply labels, and a robot at least partly mobile provided with a welding head configured to weld to the oblong metal product at least a support pin of the label, said robot being assisted by identification means of the metal product to be labeled.

In accordance with one aspect of the present invention, the apparatus comprises a feed unit to feed the pin connected to the welding head by means of a conveyor pipe in order to deliver the pin directly into the welding head.

This allows to considerably reduce the labeling times with respect to the state of the art, since the robot directly receives the pin to be welded.

Formulations of the present invention also concern a method for labeling metal products that provides: to supply an oblong metal product; to supply a label; to supply at least one pin directly into the welding head by means of a conveyor pipe connected to a feed unit; and to weld the pin associated with the label to the metal product by means of the welding head.

According to other formulations, the present invention also concerns a welding head to weld at least a support pin of a label, said welding head being installable on a robot and configured to weld the pin onto an oblong metal product. The welding head comprises at least part of a conveyor pipe to connect the welding head to a feed unit of the pin.

Formulations of the present invention concern a pin feed unit connected by a conveyor pipe to a welding head provided on a robot which is at least partly mobile.

According to another formulation, the present invention concerns a support pin for a label suitable to be used in a labeling apparatus as described above and in which the pin consists of a head and a shank, and the ratio between the weight of the head with respect to that of the shank is comprised between 1.2 and 2.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics of the present invention will become apparent from the following description of some embodiments, given as a non-restrictive example with reference to the attached drawings wherein:

- fig. 1 schematically shows a labeling apparatus:

- fig. 2 shows a support pin of a label; - fig. 3 shows a pin feed unit of fig. 1 ;

- figs. 4-6 show three positions of a feed device,

- fig. 7 is a perspective view of a welding head;

- fig. 8 is a section view of fig. 7;

- fig. 9 is a lateral view of a supply unit of fig. 1 ;

- fig. 10 is a perspective view of part of the supply unit;

- fig. 11 is a section view of the supply unit;

- figs. 12 and 13 are two section views of fig. 7 in three operating steps;

- fig. 14 is a view from above of a welding head of fig. 7.

To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can conveniently be incorporated into other embodiments without further clarifications.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

With reference to fig. 1, a labeling apparatus 10 for metal products 11 is shown. The labeling apparatus 10 can be used in a steel plant, such as a continuous casting plant, a rolling plant, or other type.

The metal products 1 1 discussed here are not limited to a specific shape, but for example may have an oblong, cubic, polyhedral, spherical or other shapes. The labeling of the metal products 11 is carried out by associating the assembly 12 consisting of a label 13 and a pin 14 with the metal product 11. In particular, the assembly 12 is formed whenever the pin 14 is associated with the label 13, for example inserted in a hole 15 of the label 13, or in portions in which notches are present, or other solutions intended to associate the pin 14 to the label 13.

In accordance with some solutions, the apparatus 10 comprises a supply unit 17 of a label 13, a robot 18 at least partly mobile between the supply unit 17 and a welding zone 16 in which the metal product 1 1 is located. The robot 18 is provided with a welding head 20 configured to weld to the metal product 1 1 at least a pin 14 supporting the label 13.

The labeling method provides to weld the pin 14 supporting the label 13 to the metal product 1 1 , advantageously, with an electric arc welding.

The robot 18 can comprise one or more mobile and articulated arms so as to position, on each occasion, the welding head 20 in a desired position of the maneuvering space of the robot 18. For example, the welding head 20 can be installed on one end of the robot 18.

According to possible solutions, the robot 18 can be assisted by means to identify at least the metal product 11 to be labeled. According to possible solutions, the identification means can be installed on the welding head 20.

The identification means can comprise a laser device 87 able to detect the metal product 11 and possibly to acquire its morphology.

According to one aspect of the present invention, the labeling apparatus 10 comprises a feed unit 19 of the pin 14 and a conveyor pipe 40 connected to the feed unit 19 and to the welding head 20 to provide the latter with the pin 14.

The present invention allows to considerably speed up the labeling operations, since the robot 18 receives the pin 14 directly in the welding head 20 even during downtimes, for example during one of the movements of the robot 18, or while the label 13 is being printed.

According to possible solutions, the feed unit 19 is able to provide, on each occasion, one pin 14 at a time directly into the welding head 20.

In accordance with possible embodiments, the labeling apparatus 10 can comprise an electric generator 22 able to supply the necessary energy to the welding head 20 to weld the pin 14.

The labeling apparatus 10 can comprise a control and command unit 23 configured to manage, command and control the functioning of the components of the apparatus 10 itself.

According to a possible embodiment, the control and command unit 23 can comprise a robot control and command unit 24 able to manage and command the movements of the robot 18.

The presence of a robot control and command unit 24 intended only to manage the robot 18 allows to obtain greater efficiency in carrying out operations compared with the state of the art, at the same time guaranteeing high levels of safety.

The control and command unit 23 can comprise a management unit 25 able to manage in whole, or in part, at least one of either the welding head 20, the supply unit 17, the electric generator 22 or possibly the robot control and command unit 24.

According to possible variants, the control and command unit 23 can comprise a user interface 26 to allow an operator to control, manage and/or command the labeling apparatus 10 remotely.

According to possible embodiments, the labeling apparatus 10 can comprise a transfer unit 84 to transfer the metal products 1 1 to be labeled in a direction of feed, and to position them on each occasion in the welding zone 16. The transfer unit 84 can comprise at least one of either a conveyor belt, a rollerway, or suchlike.

This allows to dispose the metal products 11 with their head surface 21 facing a direction orthogonal to the direction of feed. In this way, when the metal product 11 is positioned in the welding zone 16, the robot 18 can position and apply on the head surface 21 the assembly 12 consisting of the label 13 and the pin 14.

According to a possible embodiment (fig. 2), the pin 14 consists of a head 27 and a shank 28. The head 27 and/or the shank 28 can have a cylindrical or polygonal section. The head 27 has an equivalent diameter greater than the equivalent diameter of the shank 28.

The ratio between the equivalent diameter of the head 27 and the equivalent diameter of the shank 28 can be comprised between a value of 1.2 and 2, preferably between a value of 1.3 and 1.8. The hole 15 of the label 13 has sizes comprised between those of the equivalent diameter of the shank 28 and the equivalent diameter of the head 27.

This allows to make a pin 14 able to retain the label 13 without needing to apply additional retaining elements.

The head 27 can have a length shorter than the length of the shank 28. The ratio between the length of the head 27 and the length of the shank 28 can be comprised between a value of 0.2 and 0.8, preferably between a value of 0.4 and 0.6.

The head 27 can have a weight greater than the weight of the shank 28. The ratio between the weight of the head 27 and the weight of the shank 28 can be comprised between a value of 1.2 and 2, preferably between 1.3 and 1.8.

Thanks to the ratios identified, it is possible to position the pin 14 surely at the outlet of the welding head 20 so as to speed up the labeling operation compared with the state of the art.

According to possible embodiments, with reference to fig. 3, the feed unit 19 comprises a device 85 to singularize the pins 14 in order to supply on each occasion one pin 14 at a time to the welding head 20.

The feed unit 19 can comprise a feed device 30 located downstream of the singularizing device 85 and connected to the conveyor pipe 40 and configured to receive one pin 14 at a time from the singularizing device 85 and to transfer it with a defined orientation to the welding head 20 through the conveyor pipe 40. The singularizing device 85 can comprise a container 29 suitable to contain a plurality of pins 14 and a guide 31 located at the upper exit of the container 29 able to transfer the pins 14 toward the feed device 30.

According to possible embodiments, the container 29 can have an aperture facing upward through which the pins 14 are introduced which are positioned on the bottom of the container 29. The container 29 can have a truncated cone shape with its smaller section facing toward the bottom.

The container 29 can be provided in its internal wall with a helical path 33 which extends from the bottom of the container 29 until it reaches the upper edge of the aperture.

According to possible embodiments, the upper edge of the aperture can be provided with a containing wall 86 to prevent the pins 14, when the upper edge of the container 29 has been reached, from falling out of the container 29.

The container 29 can comprise a vibrating member 32 configured to make the container 29 and the pins 14 contained therein vibrate.

The vibration can be defined in one direction, or in a combination of directions, to form a compound vibrating movement, or the vibration can be a rotary vibration.

While the vibration is active, the pins 14 travel along the helical path 33, rising from the bottom to the upper edge of the container 29.

The vibrations induced in the container 29 are such as to orient the pins 14 in a predefined manner. In particular, thanks to the ratios of size and weight identified for the pin 14, there is a high probability that the pins 14 arrive on the upper edge of the container 29 with the shank 28 preceding the head 27. According to some solutions, the guide 31 is associated with the edge of the aperture, for example tangent to the latter, and is provided with a slit 34 sized to allow insertion through it only of the shank 28 of the pin 14, leaving the head 27 protruding from the slit 34. In fact, the slit 34 has a width greater than the diameter of the shank 28 and smaller than the diameter of the head 27.

Any pin 14 not positioned according to the orientation defined by the slit 34 falls into the container 29 due to the effect of the vibration and ratio of the weights between the head 27 and the shank 28.

According to a possible embodiment, in the vicinity of the slit 34 there can be a nozzle 35 oriented toward the inside of the container 29 and configured to deliver a flow of gas suitable to make any pins 14 not oriented correctly with respect to the slit 34 fall into the container 29.

According to possible solutions, the feed device 30 can comprise a fork 36 suitable to receive one pin 14 at a time with a seating 37.

The fork 36 assumes at least a gripping position in which the seating 37 is facing the guide 31, or the slit 34, and a release position, in which the pin 14 is respectively released from the seating 37.

According to possible embodiments, the fork 36 is connected to an actuator, not shown in the drawings, configured to move the fork 36 between the gripping position and the release position.

The fork 36 can be housed on a mobile body 38 of the feed device 30. The mobile body 38 is configured to move the fork 36 into at least one reception position aligned with the guide 31, in which a pin 14 arriving from the latter is inserted into the fork 36 and a delivery position in which the mobile body 38 disposes the fork 36 aligned with the conveyor pipe 40.

A movement member 39, for example an electric, pneumatic, or other type of linear actuator, is associated with the mobile body 38 to take the latter to the reception and delivery position.

When the mobile body 38 is in the reception position, the fork 36 is in the gripping position to receive the pin 14 in its seating 37. When the pin 14 is in the seating 37, the mobile body 38 moves the fork 36 into the delivery position, where the latter is taken into its release position to release the pin 14 in the conveyor pipe 40. Subsequently, the mobile body 38 returns to the reception position and the fork 36 to the gripping position. These repositionings can take place simultaneously.

The feed device 30 can comprise a thrust element 41 , for example a nozzle, or a thruster member, configured to make the pin 14 advance in the conveyor pipe 40 until it is made available to the welding head 20.

Advantageously, the thrust element 41 can be connected to a compressed air system provided to generate an intermittent fluid flow through the conveyor pipe 40.

According to possible solutions, the welding head 20 comprises a retaining head 45 connected to the conveyor pipe 40 and configured to retain in position the pin 14 arriving from the feed unit 19.

The retaining head 45 can be defined by a tubular body whose tubular cavity is connected directly or indirectly to the conveyor pipe 40 and through which the pin 14 is made to pass.

The retaining head 45 can be made of conductive material, for example copper, its alloys or other material.

According to possible embodiments, the retaining head 45 has an elasticity such as to be deformed when the pin 14 passes through it. The elasticity of the retaining head 45 allows to retain the pin 14 elastically in a desired position. The retaining head 45 is configured to perform at least three functions: to retain the pin 14 arriving from the feed unit 19, preventing it from being expelled by the welding head 20, to conduct the electric current to the pin 14 to perform the welding, and to oppose minimum resistance during extraction of the pin 14 from the welding head 20 after welding has been carried out.

In order to be able to perform these functions, according to possible solutions, the retaining head 45 is provided with elastic walls or fins 64, configured to deform radially with respect to the central axis of the retaining head 45 on the passage of the head 27 of the pin 14.

The fins 64 can be made from the presence of notches made in the tubular body and along part of the length of the retaining head 45.

According to possible solutions, if a compressed air system is used to thrust the pin 14 through the conveyor pipe 40, the pin 14 is conveyed with a thrust pressure comprised between 4 bar and 6 bar. These pressure values are particularly effective to completely discharge the shank 28 of the pin 14 from the retaining head 45, leaving only the head 27 engaged against it. In particular, it can also be provided to make part of the head 27 of the pin 14 exit from the retaining head 45 to prevent it retaining the pin 14 in the connection zone between the head 27 and the shank 28.

The welding head 20 can be provided with an electric connector 53 provided to supply electricity to the pin 14 when it is housed in the retaining head 45.

The electric connector 53 can be electrically connected to the electric generator 22. The welding head 20 can comprise a connection body 46 which connects the conveyor pipe 40 to the retaining head 45.

For example, the connection body 46 can have a tubular shape and is provided with a lateral aperture connected to the conveyor pipe 40 and through which the pin 14 can transit to reach the end of the retaining head 45.

The welding head 20 also comprises a positioning member 47 associated with the retaining head 45 in order to position the pin 14 in a precise position in the latter and to define a positioning abutment.

The positioning member 47 can have a rod-like shape and is inserted at least partly sliding in the retaining head 45 and optionally in the connection body 46, if present. The positioning member 47 can be connected to the connection body 46. The positioning member 47 can comprise a linear actuator, for example pneumatic, or electric.

In a possible solution, the positioning member 47 comprises a cylinder 50 provided with a chamber in which a piston 51 is slidingly installed.

The piston 51 (fig. 8) comprises a stem 49 which protrudes from the cylinder 50 and which, in use, is positioned in contact with the pin 14 to provide a stable abutment.

Retention rings 54, or other similar connection elements, can be provided to connect the retaining head 45 and the connection body 46 and/or the retaining head 45 and the cylinder 50.

The positioning member 47, in the case of fig. 8 the cylinder 50, can be connected to the electric connector 53, for example by means of a connection terminal 52.

The electric current supplied by the electric connector 53 can reach the pin 14 passing through the cylinder 50, the connection body 46 and the retaining head 45.

The electric current can be modified in time and/or intensity in relation to the type of material of the metal product 1 1.

The stem 49 of the piston 51 can comprise an insulating terminal 55 which can be positioned in contact with the pin 14 and provided to prevent the electric current from being supplied to the pin 14 through the piston 51, but through the cylinder 50.

In other embodiments, not shown, the pin 14 can be electrically connected to the electric connector 53 by means of the piston 51.

The welding head 20 can be associated with an earthing device 44 configured to connect the metal product 11 to earth, that is, a connector with zero electric potential, and thus allow the definition of an electric circuit which comprises the electric connector 53, the pin 14, the metal product 11 and the earthing device 44. The earthing device 44 and the electric connector 53 in turn can be connected to the electric generator 22.

The earthing device 44 can comprise a contact element 80 which can be positioned in contact with the metal product 11 to define the closure of the electric circuit. The contact element 80 can be supported by a containing body 42.

The contact element 80 allows to reduce losses of electric current and to exploit the real electric current supplied by the electric generator 22. The contact element 80 can have an ogive shape.

An elastic device 82 can be associated with the contact element 80 and is configured to elastically contrast the movement of the contact element 80.

The elastic device 82 can comprise a spring, or a pneumatic thrust member, or other type, acting on the contact element 80 and located in the support body 81.

When the welding head 20 is taken in proximity to the metal product 1 1 , the contact element 80 is put under pressure against the latter also by means of the elastic device 82 which causes an elastically contrasted movement of the contact element 80.

In accordance with possible solutions, the welding head 20 is installed, at least partly, in a containing body 42 connected to one end of the robot 18. The contact element 80, or possibly the support body 81, can be installed on the containing body 42.

According to possible embodiments, a movement unit 56 can be associated with the welding head 20 and is provided to move the welding head 20 with respect to the end of the robot 18 and in a direction incident to the surface of the metal product 11 on which the pin 14 is to be welded.

The movement unit 56 can be installed in the containing body 42, for example in a compartment 48 of the latter, and moves the welding head 20 with respect to the containing body 42.

In fact, during welding operations, it can be provided that the robot 18 carries the welding head 20 with the pin 14 in contact with the metal product 1 1. Also the contact element 80 is positioned in contact under pressure with the metal product 11.

In this condition, the movement unit 56 causes the welding head 20 to move away from the metal product 1 1 by a predefined distance, for example 2-5mm, which is suitable to enable to trigger the electric arc. When the electric arc is triggered, the movement unit 56 moves the welding head 20 into proximity with the metal product 11 so as to thrust the pin 14 under pressure against the latter and determine the welding. During the movements of the welding head 20, the contact element 80 remains in contact with the metal product 1 1, thus allowing to generate the electric arc.

Thanks to the movement of the welding head 20 alone, it is possible to control, precisely and rapidly, the movements required to generate correct welding.

The movement unit 56 can comprise a sliding rod 57 attached to the welding head 20 and sliding with respect to the containing body 42. An elastic element 58 can be provided between the containing body 42 and the sliding rod 57 to keep the welding head 20 normally in a condition thrust toward the outside of the containing body 42.

The containing body 42 can comprise an abutment element 59 on which the elastic element 48 is positioned, which can be of an adjustable type to adjust the elastic thrust action of the elastic element 48.

The movement unit 56 can comprise an actuator, in this case an electromagnet 60 configured to move the sliding rod 57 with respect to the containing body 42. In particular, the electromagnet 60 can have a through aperture 61 in which the sliding rod 57 is slidably inserted, at least partly.

By powering the electromagnet 60, an electromagnetic field is generated which acts on the sliding rod 57 and generates a displacement force of the latter. The direction of movement of the sliding rod 57 is defined by the electric power parameters of the electromagnet 60.

The sliding rod 57 can comprise abutment portions 62, for example with the electromagnet 60, defining positions of maximum movement of the welding head 20 in the containing body 42.

According to possible embodiments, a detection device 63 can be provided to detect the position of the welding head 20 with respect to the containing body 42. In particular, the detection device 63 also allows to control the distance between the pin 14 and the surface of the metal product 11. The detection device 63, for example, can be a linear transducer, or potentiometer.

During the step of positioning the shank 28 of the pin 14 in contact with the metal product 1 1, the piston 51 of the positioning member 47 is in contact with the head 27 of the pin 14 so as to provide a stable and precise reference which keeps the pin 14 in position.

During welding operations, it is provided to move the welding head 20 with the robot 18 into proximity with the metal product 11 to be welded by putting the pin 14 in contact with the latter. Subsequently, with the robot 18 stationary, the electromagnet 60 moves the pin 14 away from the metal product 11. During this movement, the elastic element 58 is loaded. When the electric arc is triggered between the pin 14 and the metal product 11, the electromagnet 60 is deactivated and the elastic element 58 generates a rapid movement of the welding head 20 toward the metal product 1 1. The elastic element 58 also guarantees a reciprocal pressure between the pin 14 and the metal product 1 1, suitable to allow the welding. During these movements, the positioning member 47 guarantees that the pin 14 remains in position with respect to the retaining head 45.

A retaining device 43 can be associated with the welding head 20 to retain the label 13 in position when it is associated with the pin 14.

The retaining device 43 can comprise suction means associated with a suction cup 65 provided to retain the label 13, by means of depression, in a predefined position with respect to the welding head 20.

In particular, the suction cup 65 is activated when the label 13 is removed from the supply unit 17 of the labels 13. The suction cup 65 can be connected to the containing body 42 by a support rod 66.

According to possible embodiments, shown in figs. 9-11, the supply unit 17 comprises a printing unit 67 configured to print on the label 13 the specific information relating to the metal product 11 to be labeled.

The supply unit 17 comprises a transfer device 68 configured to transfer the label 13 from a removal station 69, located at exit from the printing unit 67, to a delivery station 70, where the robot 18 is able to position the welding head 20 to remove the label 13 with the pin 14.

The supply unit 17 can comprise a movement guide 71 on which the transfer device 68 is slidingly installed, for example by means of a slider 72, mobile between the removal station 69 and the delivery station 70.

The transfer device 68 can comprise a positioning plane 73 on which the label 13 provided by the printing unit 67 is positioned.

An alignment member can be associated with the positioning plane 73, in this case an alignment pin 75 provided to define a correct positioning of the label 13 with respect to the positioning plane 73.

In the positioning plane 73 a seating 74 can be provided, through which the alignment pin 75 can be moved between a position retracted from the positioning plane 73, during which the label 13 is supplied to the latter, and a position protruding from the positioning plane 73 in which the alignment pin 75 is positioned in the hole 15 of the label 13 and maintains its position.

An actuator 76 can be associated with the alignment pin 75, to move the alignment pin 75 from the retracted position to the protruding position.

The transfer device 68 can comprise a retaining member 76 configured to retain the label 13 in position on the positioning plane 73.

This prevents the label 13, during the transfer from the removal station 69 to the delivery station 70, from rotating and/or disengaging from the alignment pin 75.

The retaining member 76 can comprise a mobile element 77 which can be positioned, by means of an actuator 78, between at least one position in which the mobile element 77 retains the label 13 in contact with the positioning plane 73, and a position in which the mobile element 77 is not in contact with the label 13 and the positioning plane 73. For example, the mobile element 77 can be hinged to the side of the positioning plane 73.

The mobile element 77 can have at least one shaped seating 79 of a shape mating with the insertion zone of the alignment pin 75 so that the mobile element 77 does not interfere with the latter.

When the transfer device 68 is in the delivery station 70 the alignment pin 73 is removed from the hole 74 and the robot 18 takes the welding head 20 with the pin 14 retained by the retaining head 45 on the hole 74 of the positioning plane 73. The pin 14 is inserted, with its shank 28 in the hole 15 of the label 13 and the retaining device 43 is activated to retain the label 13 in position with respect to the welding head 20 and keep the pin 14 inserted in the hole 15.

Subsequently, the label 13 is released from the mobile element 77, and the robot 18, moving the welding head 20, takes the assembly 12 toward the metal product 11 for welding.

In particular, while the pin 14 is retained by the retaining head 45 and the label 13 is retained by the suction cup 65 of the retaining device 43, the welding head 20 is positioned so as to put the pin 14 in contact with the metal product 11 to be labeled.

The choice of the zone in which to position the pin 14 can be made by means of a laser device 87 configured to scan and detect the morphology of the metal product 11, or of the head surface 21.

The laser device 87 is configured to detect the distance of the welding head 20 from the head surface 21 of the metal product 11 by means of a triangulation system integrated therein. The robot 18 is moved to position the welding head 20 according to the data detected by the laser device 87.

According to possible variants, the welding head 20 can also comprise a camera 83 configured to verify whether the label 13 shows the correct information relating to the specific metal product 11.

The verification with the camera 83 can be performed both at the time the label 13 is removed from the feed unit 17, and also after welding. In the latter case, the camera 83 also verifies that the assembly 12 is correctly integrated with the metal product 11.

It is clear that modifications and/or additions of parts may be made to the apparatus 10 and method for labeling metal products 11 as described heretofore, without departing from the field and scope of the present invention.

It is clear that modifications and/or additions of parts may be made to the feed unit 19, the welding head 20 and the pin 14 for labeling metal products 1 1 as described heretofore, without departing from the field and scope of the present invention.

It is also clear that modifications and/or additions of parts may be made to the supply unit 17 as described heretofore, without departing from the field and scope of the present invention.

It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of apparatus 10 and method for labeling metal products 11, as well as a feed unit 19, a welding head 20, a pin 14 and a supply unit 17, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.

Claims

1. Apparatus for labeling metal products (1 1 ) comprising a supply unit (17) to supply a label (13), a robot (18) at least partly mobile between at least said supply unit (17) and a welding zone (16) where said metal product (11) is positioned, said robot (18) being provided with a welding head (20) configured to weld to said metal product (1 1) at least a support pin (14) of said label (13), said robot (18) being assisted by identification means of said metal product (11) to be labeled, characterized in that said apparatus comprises a feed unit (19) to feed said pin (14) and a conveyor pipe (40) connecting said feed unit (19) to said welding head (20) in order to deliver said pin (14) directly into said welding head (20).

2. Apparatus as in claim 1, characterized in that said welding head (20) comprises a positioning member (47) and a retaining head (45) cooperating with each other to position and retain said pin (14) in said retaining head (45).

3. Apparatus as in claim 2, characterized in that said retaining head (45) is configured to deform elastically so as to house and retain said pin (14) in position due to elastic action.

4. Apparatus as in any claim hereinbefore, characterized in that said robot (18) with said pin (14) positioned is configured to remove said label (13) and to position the assembly (12) consisting of said pin (14) and said label (13) with respect to said metal product (1 1) to be labeled.

5. Apparatus as in any claim hereinbefore, characterized in that said feed unit (19) comprises a singularizing device (85) configured to supply in succession one of said pins (14) orientated at a time to said welding head (20) by means of said conveyor pipe (40).

6. Method for labeling metal products (1 1) that, in a welding zone (16), provides to associate a label (13) supplied by a supply unit (17) with a metal product (1 1) defined by identification means, to weld to said metal product (1 1) at least a pin (14) that supports said label (13), by means of a welding head (20) provided on a robot (18) that is at least partly mobile between at least said supply unit (17) and said welding zone (16), characterized in that it provides to supply said pin (14) directly into said welding head (20) from a feed unit (19) by means of a conveyor pipe (40).

7. Method as in claim 6, characterized in that it provides to supply said pin (14) in downtime, while said robot (18) performs other designated functions.

8. Method as in claim 6 or 7, characterized in that it provides to position said pin (14) and elastically retain it in position in a retaining head (45) by means of a positioning member (47) at least until the labeling has finished, said retaining head (45) and said positioning member (47) being part of said welding head (20).

9. Method as in any of the claims from 6 to 8, characterized in that it provides to remove said label (13) with said pin (14) retained elastically in said retaining head (45) and to position the assembly (12) consisting of said label (13) and said pin ( 14) in relation to said metal product (1 1).

10. Method as in any of the claims from 6 to 9, characterized in that it provides to position, in contact with said metal product (11), an earthing device (44) associated and cooperating with said welding head (20).

11. Method as in any of the claims from 6 to 10, characterized in that it provides to generate an electric arc, first distancing said pin (14) from said metal product (11) to then proceed with the welding.

12. Support pin for a label (13) suitable to be used in an apparatus (10) for labeling metal products (11) as in any of the claims from 1 to 5, characterized in that it consists of a head (27) and a shank (28), said head (27) having an equivalent diameter greater than the equivalent diameter of said shank (28), wherein the ratio between the weight of said head (27) and the weight of said shank (28) is comprised between a value of 1.2 and 2.

13. Welding head of a pin (14) to support a label (13) to a metal product (11) provided on a robot (18) at least partly mobile between at least a supply unit (17) of said label (13) and a welding zone (16) in which said metal product (1 1) is positioned, said robot (18) being assisted by identification means of said metal product (1 1) to be labeled, characterized in that said welding head comprises at least part of a conveyor pipe (40) provided to connect the welding head to a feed unit (19) of said pin (14).

14. Welding head as in claim 13, characterized in that it comprises a retaining head (45) and a positioning member (47) cooperating with each other to position and retain said pin (14) in position in said retaining head (45).

15. Welding head as in claim 13 or 14, characterized in that said retaining head (45) is configured to deform elastically so as to house and retain said pin (14) elastically.

16. Feed unit for feeding pins (14) of a welding head (20) provided on a robot (18) at least partly mobile between at least a supply unit (17) of labels (13) and a welding zone (16), characterized in that said feed unit is connected to said welding head (20) by means of a conveyor pipe (40).

17. Feed unit as in claim 16, characterized in that it is provided with an intermittent compressed air conveying system able to convey said pin (14) as far as said welding head (20) through said conveyor pipe (40).