Packaging machine and packaging method

Abstract

A packaging machine (1) for packaging loads (100) with film (50) comprises: a main frame (2) which supports in a slidable manner a support carriage (3); a mobile ring (4) which is rotatable and supports a development unit (5) provided with a reel (51) of film, pre-stretching rollers (52, 53) and at least one electric motor (37, 38) to rotate said pre-stretching rollers (52, 53); sliding electric contact means (10) for supplying electric current to the development unit (5) and / or exchanging electric signals with the development unit (5) and comprising brush means (11) fixed to the mobile ring (4) and arranged in a slidable manner against conductive bar means (12) fixed to a support ring (6) of the support carriage (3); drive and control means (40) fixed to the brush means (11) and to the development unit (5) to drive and control the electric motor (37, 38) and comprising detector means (46) connected to the brush means (11) and configured to detect and record possible interruptions in the supply of electric current during operation.

Description

Technical Field

[0001] This invention relates to a machine for packaging loads using films or strips of plastic and / or paper materials, and more particularly to a packaging machine of the horizontal rotating ring type. The invention also relates to a packaging method implemented by a packaging machine of the horizontal rotating ring type. Background Technology

[0002] Known packaging machines with horizontal rotating rings include a main frame (with a secondary frame slidably connected to the main frame) or a support bracket that forms a rotatably support ring structure or rotating ring to which a unit for unfolding or supplying film is fixed.

[0003] The rotating ring can rotate about the vertical packaging axis, while the support bracket can move linearly and parallel to the packaging axis. In this way, the film unfolding unit can move parallel to and about the packaging axis, while the load to be packaged remains stationary. The load typically consists of one or more products grouped and arranged on a tray.

[0004] The film or strip unwound by a spool mounted on an unfolding unit is wrapped around the load in such a way that a series of interwoven strips or belts with a spiral pattern are formed due to the combination of linear and rotational movement of the unfolding unit.

[0005] For plastic films, the unfolding unit typically includes: a pair of pre-stretch rollers, including a slow roller and a fast roller, located upstream and downstream of the film movement, respectively, for stretching and unfolding the stretchable film; and one or more deflecting rollers or return rollers for turning the film toward the load during unfolding. By appropriately adjusting the speed difference between the two pre-stretch rollers, the film can be stretched or elongated by a certain amount before being wrapped on the load, based on a fixed pre-stretch or elongation percentage.

[0006] The unfolding unit typically includes an electric motor that rotates one of the two pre-stretch rollers, which serves as the drive (master) roller (typically the fast roller), and the other pre-stretch roller, which serves as the driven (slave) roller (typically the slow roller), via a mechanical transmission assembly. Thus, a fixed transmission ratio is established between the fast and slow rollers based on the pre-stretch or elongation value to be obtained on the film.

[0007] It is also known to provide an unfolding device with a pair of electric motors arranged to drive two pre-stretch rollers separately and independently, thereby allowing the film elongation to be varied, i.e., the percentage of pre-stretch or elongation to be changed during the packaging of the load.

[0008] Sensors are also installed on the unfolding unit to detect the operating parameters of the packaging machine. In some cases, devices are also installed for transmitting control signals via radio (wireless).

[0009] To power one or more electric motors driving the pre-stretch rollers and sensors mounted on the unfolding unit, and / or to exchange control signals between the unfolding unit and the control unit of the packaging machine, some annular packaging machines incorporate sliding electrical contact devices. These devices include annular structures fixed to a support bracket and having multiple conductive annular rods (sliding contacts) on their inner sidewalls. Corresponding contact brushes slide on these conductive annular rods, which are alternatively mounted on a rotating ring and electrically connected to the electric motors and sensors of the unfolding unit. The conductive rods are connected to a circuit board via cables to drive and control the packaging machine.

[0010] The conductive rod is made of a highly conductive metallic material (typically copper) and is bent (rolled) around the inner wall of the annular structure and fixed thereto. The brush includes a sliding element made of a material with high conductivity and a low coefficient of friction (typically a graphite-based sintered material).

[0011] The brush is held abutting the conductive rod by a predetermined thrust through an elastic element (such as a spring) to prevent it from detaching from the conductive rod during operation due to vibration, irregular shape of the circular track, dirt and debris.

[0012] Although brushes are made of materials with a low coefficient of friction, they will still wear down gradually and should be inspected and possibly replaced frequently to avoid interruptions in the supply of current and / or control signals.

[0013] In particular, for sensors and / or signal transmission devices (wireless transmission boards), any discontinuity or interruption in the low-voltage DC current supply, even for a fraction of a second, can cause packaging machine malfunction.

[0014] To avoid such failures during the use of packaging machines, it is necessary to accurately plan regular maintenance interventions for sliding electrical contact devices (especially brushes).

[0015] In known packaging machines, the centrifugal force acting on the brush during the rotation of the rotating ring also exacerbates brush wear. This centrifugal force, along with the spring, keeps the brush in contact with the annular conductive rod. However, at high rotational speeds of the rotating ring, the centrifugal force (proportional to the square of the angular velocity) can be quite high, leading to rapid brush wear.

[0016] In known packaging machines, because the brush is located inside the rotating ring and in contact with an annular track fixed to the inner wall of the annular support structure, it is difficult for operators to access the brush for control and replacement. Therefore, these maintenance operations are both laborious and time-consuming.

[0017] Although wear is minimal, the ring-shaped conductive rod must be inspected regularly and may need to be replaced.

[0018] However, replacing the ring-shaped conductive rod in known packaging machines is a rather complex and difficult process because the conductive rod is designed as a straight section. These straight sections must be cut to the required length before assembly and then bent (calendered) into a ring / arc shape. The resulting ring-shaped conductive rod must then be fixed to the inner wall of the ring support structure. The entire replacement process requires more specialized operators and results in significant downtime for the packaging machine, thus extending production time. Summary of the Invention

[0019] The object of the present invention is to improve a known packaging machine having a horizontal rotating ring and a sliding electrical contact device for transmitting current and / or control / command signals to the film unfolding unit.

[0020] Another objective is to provide a packaging machine that allows for a significant reduction in wear on the contact brushes and annular conductive rods of the sliding electrical contact device, thereby increasing the length of its replacement and maintenance intervals.

[0021] Another objective is to provide a packaging machine that allows for quick and easy replacement of the contact brush and the annular conductive rod, thereby allowing for a significant reduction in downtime of the packaging machine.

[0022] Another objective is to develop a packaging machine that allows for the detection of any faults in the sliding electrical contact device, particularly for arranging maintenance and / or replacement of the contact brush and annular conductive rod.

[0023] A first aspect of the present invention includes a packaging machine according to some embodiments of this application.

[0024] A second aspect of the invention includes a method for using a film or tape-packaged load as described in other embodiments of this application. Attached Figure Description

[0025] The invention can be better understood and practiced with reference to the accompanying drawings, which illustrate exemplary and non-limiting embodiments of the invention, wherein: - Figure 1 This is a perspective view of the packaging machine according to the present invention; - Figure 2 yes Figure 1 A close-up view of the packaging machine; - Figure 3 This is a partial enlarged perspective view of the packaging machine of the present invention viewed from below, with the sliding electrical contact device particularly shown; - Figure 4 This is another partially enlarged perspective view of the packaging machine of the present invention, viewed from below, showing the sliding electrical contact device; - Figure 5This is a partially enlarged perspective view of the packaging machine of the present invention, showing the sliding electrical contact device, the moving ring, and the support ring; - Figure 6 This is a plan view of the contact brush; - Figure 7 It is a 3D view of multiple contact brushes; - Figure 8 This is a partial perspective view of the packaging machine of the present invention, wherein the support ring of the conductive rod device is removed from the support bracket of the packaging machine; - Figure 9 yes Figure 8 The magnified details specifically show the hook elements of the detached and spaced support rings and the connecting elements of the support bracket; - Figure 10 This is a partial perspective view of the packaging machine of the present invention during the first step of assembling the support ring to the support bracket; - Figure 11 yes Figure 10 The magnified details show the hook and connecting elements; - Figure 12 This is a partial perspective view of the packaging machine of the present invention during the second step of assembling the support ring to the support bracket; - Figure 13 yes Figure 10 The magnified details show the hook and connecting elements; - Figure 14 This is a partial perspective view of the packaging machine of the present invention during the third and final stages of assembling the support ring to the support bracket; - Figure 15 yes Figure 10 The magnified details show the hook and connecting elements; - Figure 16 This is a schematic diagram of the packaging machine of the present invention, which specifically shows the sliding electrical contact device, the drive and control device, and the electric motor and sensor device of the unfolding unit. Detailed Implementation

[0026] refer to Figures 1 to 5 The diagram schematically illustrates a packaging machine 1 according to the invention, which is arranged to package a load 100 with a film 50 or strip of plastic and / or paper material (e.g., a cold-stretchable type of plastic film).

[0027] The packaging machine 1 includes a main frame 2 and a support bracket 3. The main frame 2 is provided with a plurality of support columns 13 (e.g., four) interconnected by a beam device 14. The support bracket 3 is slidably supported by the main frame 2 and moves along the working direction W (particularly the basically vertical direction).

[0028] The packaging machine 1 also includes a moving ring 4 and an unfolding unit 5. The moving ring 4 is rotatably supported by a support bracket 3 and can rotate around a packaging axis X parallel to the working direction W. The unfolding unit 5 is fixed to the moving ring 4 and is equipped with a film roll 51 and pre-stretch rollers 52 and 53 for unfolding and pre-stretching the film.

[0029] Therefore, the moving ring 4 is arranged horizontally and parallel to the support plane P where the packaging machine 1 is located.

[0030] The unfolding unit 5 specifically includes: a pair of pre-stretch rollers 52, 53 that unfold and stretch or elongate the film 50 from the roll 51; and one or more return rollers 54 that turn the film 50 toward the product or product group to form the load 100 to be packaged. The unfolding unit 5 also includes at least one electric motor 37, 38 for driving the pre-stretch rollers 52, 53, and a sensor device 39 for detecting the operating parameters of the unfolding unit 5.

[0031] The load 100 is supported by a conveyor 9 of a known type and moves in and out of the packaging machine.

[0032] The sliding electrical contact device 10 is configured to transmit current to the deployment unit 5 and / or exchange electrical signals with the deployment unit 5.

[0033] The sliding electrical contact device 10 specifically includes a brush device 11 fixed to the moving ring 4 and a conductive rod device 12 fixed to the support ring 6, the support ring 6 being connected to the support bracket 3, and particularly coaxially connected to the support bracket 3 with the moving ring 4. In operating configuration A, the brush device 11 slidably abuts against the conductive rod device 12 to supply current and / or exchange electrical signals with the deployment unit 5.

[0034] The support ring 6 is made of, for example, a metal plate and includes an outer side wall 16, which is cylindrical and parallel to the packaging axis X. The outer side wall 16 faces outward and towards the support post 13.

[0035] The support ring 6 is removably connected to the support bracket 3, and in particular, it is interchangeable with another identical support ring 6 (e.g., a new one) that is provided with the conductive rod device 12.

[0036] The conductive rod device 12 includes a plurality of annular conductive rods 31, 32, 33, which are made of copper and are fixed to the outer wall 16 of the support ring 6 in a parallel and adjacent manner. The brush device 11 includes a plurality of contact brushes 20, each of which is configured to slidably abut the corresponding annular conductive rod 31, 32, 33 in the operating configuration A.

[0037] Each of the annular conductive rods 31, 32, and 33 has a circular shape.

[0038] The support ring 6 includes a hook device 7 arranged to removably and reversibly engage the connection device 8 of the support bracket 3 in the assembly configuration M, in which the support ring 6 is coupled to and supported by the support bracket 3, as better explained in the following disclosure.

[0039] Specifically, the hook device includes a plurality of hook elements 7, which are configured to removably engage corresponding connecting elements 8 of the connecting device of the support bracket 3 in the assembly configuration M.

[0040] Hook elements 7 (e.g., three) are fixed to the inner wall 17 of the support ring 6 in a regularly spaced manner.

[0041] Special Reference Figure 9 , Figure 11 , Figure 13 , Figure 15 Each hook element 7 includes an adjacent portion 7a adapted to abut a support portion 8a (e.g., a generally horizontal support portion) of the corresponding connecting element 8, and is provided with a shaped end 7b adapted to engage a through groove 8b formed in the support portion 8a, at least in the assembly configuration M.

[0042] More specifically, each hook element 7 has a rectangular flat shape and includes a lower portion 7c fixed to (e.g., welded to) the inner sidewall 17 of the support ring 6 and a hook-shaped upper portion including an adjacent portion 7a with a shaped end 7b.

[0043] The support bracket 3 includes a plurality of connecting elements 8, for example, the number of which is equal to the number of hook elements 7, each connecting element 8 being provided with a pair of angle brackets having a corresponding support portion 8a with a slot 8b.

[0044] The fixing devices 15 and 19 are configured to reversibly fix the support ring 6 to a plurality of connecting elements 8 in the assembly configuration M.

[0045] The fixing devices 15, 19 include, for example, screws 15 adapted to connect the connecting element 8 to the support ring 6. More precisely, each connecting element 8 is secured to the support ring 6 by a pair of screws 15 inserted into corresponding holes on the support portion 8a of the connecting element 8 and engaged with a nut 19 fixed (particularly welded) to the upper edge of the support ring 6.

[0046] In the embodiment of the packaging machine 1 of the present invention shown in the accompanying drawings, the unfolding unit 5 includes a pair of electric motors 38 and 39, which are adapted to move two pre-stretch rollers 52 and 53 respectively. The sensor device 39 includes, for example, a sensor adapted to detect the packaging force of the film, an encoder sensor for measuring the rotational speed of the electric motors 38 and 39, a sensor for detecting the end of the film on the roll, etc.

[0047] Electric motors 37, 38 and / or sensor device 39 are electrically connected to brush device 11. Conductive rod device 12 is electrically connected to power supply device configured to supply current and / or central control unit 60 of packaging machine 1.

[0048] In the embodiment of the packaging machine 1 shown and described, the brush device 11 is arranged to receive current for the unfolding unit 5 only from the conductive rod device 12.

[0049] For this purpose, the conductive rod device 12 includes two first annular conductive rods 31 for transmitting a first current, particularly low-voltage (e.g., 24V) direct current, three second annular conductive rods 32 for transmitting a second current, particularly three-phase alternating current, and a third annular conductive rod 33 for protective grounding connection.

[0050] However, in an embodiment of the packaging machine not shown, the brush device 11 and the conductive rod device 12 are also adapted to transmit control and command signals between the unfolding unit 5 and the central control unit 60 of the packaging machine 1, particularly through specific contact brushes and annular conductive rods.

[0051] The packaging machine 1 of the present invention also includes a drive and control device 40, which is configured to drive and control electric motors 37 and 38 and fixed to the support ring 6.

[0052] A housing 41 is provided to house the drive and control device 40. The housing 41 is fixed to the moving ring 4, for example, opposite to and facing the deployment unit 5 to act as a counterweight.

[0053] The drive and control device 40 includes, for example, one or more inverters 42 and a local control unit 43 (e.g., a PLC) to drive and control the operation of the electric motors 38, 39. Characteristically, the drive and control device 40 includes two inverters 42 connected to two corresponding electric motors 37, 38 powered by three-phase alternating current supplied through corresponding brushes 20 connected to the first annular conductive rod 31, and controlled by the local control unit 43.

[0054] Two inverters 52, controlled by a local control unit 43, supply power to the electric motor in a controlled manner so as to precisely regulate its speed and / or the power supplied.

[0055] The local control unit 43 is powered by a first current, i.e., low-voltage (24V) DC, for example, through a corresponding brush 20 connected to the second annular conductive rod 32. Similarly, the sensor device 39 mounted on the deployment unit 5 is powered by the first current through the same brush 20 and is connected to the local control unit 43 to transmit signals related to the measurements and / or detections being performed.

[0056] In the illustrated embodiment of the packaging machine 1, the drive and control device 40 further includes a radio or wireless transceiver 44 that connects the local control unit 43 to another radio or wireless repeater 61 of the central control unit 60 of the packaging machine 1.

[0057] For example, the radio or wireless transceiver device 44 located within the housing 41 is also powered by the first DC power supply.

[0058] At least one backup battery 45 or buffer battery is provided connected to the brush device 11 to receive a first current, particularly low-voltage DC, from the conductive rod device 12, and is connected to the drive and control device 40 so that the drive and control device can be continuously powered by the first current even if the transmission of the first current is interrupted due to a failure of the sliding electrical contact device 10.

[0059] Specifically, the backup battery 45 is inserted between the contact brush 20 abutting against the first annular conductive rod 31 and the local control unit 43, sensor device 39, and wireless transceiver device 44. Even if the sliding electrical contact device 10 malfunctions due to wear and / or dirt on the contact brush 20 and / or annular conductive rods 31, 32, 33, the backup battery 45 ensures the continuity of the DC first current supply, even if the DC first current is briefly interrupted.

[0060] The drive and control device 40 also includes a detector device 46, which is connected to the brush device 11 to receive current from the brush device and is configured to detect and record any interruption in the supply of said current during operation of the packaging machine 1.

[0061] The central control unit 60 is configured to receive data related to the interruption of current supply from the detector device 46, and to determine maintenance work for the brush device 11 and / or the conductive rod device 12 based on the data.

[0062] More precisely, the detector device 46 is capable of detecting and recording the frequency and duration of current interruptions, and transmitting the relevant information to the central control unit 60 via the local control unit 43 to verify the operation of the packaging machine 1. In practice, the detector device 46 is connected to the local control unit 43 to transmit data related to interruptions in the current supply. By analyzing the frequency and duration of the interruptions, maintenance work such as cleaning and / or replacing the contact brushes 20 and / or the annular conductive rods 31, 32, and 33 can be scheduled.

[0063] In the illustrated embodiment, the detector device 46 receives a first current, i.e., low-voltage DC, from the brush device 11 and is therefore connected to the contact brush 20 abutting against the first annular conductive rod 31, i.e., it is connected in parallel to the backup battery 45.

[0064] The brush device 11 also includes a contact brush 20, which slides against the third annular conductive rod 33 for protective grounding connection of devices and equipment mounted on the deployment unit 5 and the moving ring 4.

[0065] Special Reference Figures 5 to 7 Each contact brush 20 is removably fixed to the moving ring 6, and in particular, it can be interchanged with another identical contact brush 20, for example in the case of excessive wear or failure.

[0066] Each contact brush 20 includes at least one conductive slide block 23, which is arranged to slidably abut against an annular conductive rod and a fixing element 24. The fixing element 24 is reversibly coupled to a support device 25 fixed to a movable ring 6, particularly via an interlocking system with flexible clips. The conductive slide block 23 is preferably made of graphite or a graphite and copper alloy and is provided with a seat 23a for coupling to an end connector of a cable.

[0067] The contact brush 20 also includes a support device 26, which is arranged to connect the conductive slider 23 to the fixing element 24 and allows the conductive slider 23 to be adjusted, particularly on an adjustment plane orthogonal to the packaging axis X and the outer wall 16 of the support ring 6.

[0068] Each contact brush 20 includes an elastic device 27 that acts on a conductive slider 23 to hold it against a corresponding annular conductive rod with a defined contact force in operating configuration A.

[0069] In the illustrated embodiment, each contact brush 20 includes a pair of conductive sliding blocks 23, which are adjacent and aligned to abut against the same annular conductive rod. The support device 26 includes, for example, a support element 28 to which the two conductive sliding blocks 23 are fixed, and a support arm 29 rotatably connected to and supporting the support element 28. An elastic device 27, including, for example, a traction coil spring, connects the end of the support arm 29 connected to the fixed element 24 to the support element 28.

[0070] The bracket devices 25 and 35 are adjustablely fixed to the movable ring 6 to allow the distance between the brush device 11 and the conductive rod device 12 to change along an adjustment direction orthogonal to the packaging axis X.

[0071] The support assemblies 25 and 35 include a first support 25 and a second support 35. The first support 25 is angular, and the fixing element 24 of the contact brush 20 is removably fixed to the first support 25. The second support 35 is angular, supports the first support 25, and is adjustablely and reversibly fixed to the moving ring 4. The second support 35 has a plurality of first through slots 35a, for example two, for connection to the first support 25 by screws. The first slots 35a allow adjustment of the position of the first support 25 in a direction parallel to the packaging axis X. The second support 35 also has a plurality of second through slots 35b, for example four, for connection to the moving ring 4 by screws. The second slots 35b allow adjustment of the position of the second support 35 in an adjustment direction (particularly perpendicular to and radial to the packaging axis X). In this way, when the conductive sliding block 23 of the contact brush 20 wears, the position of the conductive sliding block relative to the annular conductive rods 31, 32, and 33 can be quickly and easily modified, so that the brush 20 is more precisely closer to the annular conductive rods 31, 32, and 33, thereby keeping them correctly abutting each other by the predetermined contact force applied by the elastic device 27.

[0072] During operation of the packaging machine 1 of the present invention in operation configuration A, the contact brush 20 of the brush device 11 abuts against the annular conductive rods 31, 32, 33 of the conductive rod device 12, and ensures the power supply of the motor device 37, 38, sensor device 39 and drive and control device 40, especially three-phase alternating current and low-voltage direct current.

[0073] Because of the elastic device 27, the conductive sliding block 23 of the brush 20 abuts against the annular conductive rods 31, 32, and 33 with a predetermined contact force or preload force, thus ensuring proper contact and avoiding any separation caused by, for example, vibration or shape error of the annular conductive rods, which could lead to failure of the unfolding unit 5, and thus failure of the packaging machine.

[0074] Since the annular conductive rods 31, 32, and 33 are fixed to the outer wall 16 of the support ring 6, the centrifugal force acting on the contact brush 20 is not added to the preload force of the elastic device 27, but is subtracted from it. Thus, by increasing the rotational speed of the moving ring 4, the resultant force acting on the contact brush 20 decreases, thereby reducing the friction and wear on the contact brush. However, the preload force applied by the elastic device 27 is calculated to ensure that even at the highest rotational speed of the moving ring 4, the conductive sliding block 23 will not disengage from the annular conductive rods 31, 32, and 33.

[0075] Therefore, this special configuration of the sliding electrical contact device 10 of the packaging machine 1 of the present invention provides a longer maintenance interval than that required for packaging machines in which the annular conductive rods 31, 32, 33 are mounted on the inner sidewall of the support ring.

[0076] The location of the contact brushes 20 outside the support ring 6 also allows the operator to easily and conveniently inspect them, especially allowing their position relative to the annular conductive rods 31, 32, 33 to be adjusted in the adjustment direction (e.g., due to wear).

[0077] Since the fixing element 24 is reversibly coupled to the first bracket 25 via an interlocking system with flexible clips, and since the cable is reversibly coupled to the seat 23b of the conductive slider 23 via a connector, each contact brush 20 can be easily and quickly replaced even without removing the first bracket 25 or the second bracket 35 from the moving ring 4.

[0078] If the annular conductive rods 31, 32, and 33 are worn excessively, they can be replaced quickly and easily. Simply remove the support ring 6 to which the annular conductive rod is fixed from the support bracket 3 and replace it with the same support ring 6 that has the annular conductive rods 31, 32, and 33.

[0079] Figures 8 to 15 The replacement process is shown, including the steps of assembling the support ring 6 with the annular conductive rods 31, 32, 33 to the support bracket 3.

[0080] In the first step of lowering the movable carriage 3 of the packaging machine 1 to a suitable height ( Figure 8 and Figure 9 In the second step, the support ring 6 to be assembled is supported on the conveying device 9 below the movable bracket 3. The conveying device 9 is substantially coaxial with the packaging axis X and the movable ring 4. Then, in the second step... Figure 10 and Figure 11 In the process, for example, two operators lift the support ring 6 so that the adjacent portion 7a of the hook element 7 is close to the support portion 8a of the corresponding connecting element 8. Specifically, the adjacent portion 7a is slightly higher than the support portion 8a, so that in the third step ( Figure 12 and Figure 13 In the fourth step, by slightly rotating the support ring 6 around the packaging axis X, the formed end 7b of the adjacent portion 7a overlaps and aligns with the through groove 8b formed in the support portion 8a. Figure 14 and Figure 15 In this assembly configuration M, the support ring 6 is stably connected to the support bracket 3, and the support ring 6 is lowered so that the abutment portion 7a rests on the support portion 8a, and the shaped end 7b is inserted into the through groove 8b. Therefore, in this assembly configuration M, it is not necessary to keep the support ring 6, which is already supported and connected to the support bracket 3, raised; instead, it is simply constrained to the multiple connecting elements 8 by the fixing devices 15, 19. In particular, only one operator is needed to screw the screw 15 inserted into the hole of the support portion 8a of the connecting element 8 onto the nut 19 fixed on the upper edge of the support ring 6.

[0081] Therefore, the packaging machine 1 of the present invention can not only significantly reduce the wear suffered by the contact brush 20 and the annular conductive rods 31, 32, 33 (thereby increasing the length of their replacement maintenance intervals), but also, thanks to the assembly of the annular conductive rods on the outer wall 16 of the support ring 6, allows for easy and quick replacement of the contact brush 20 and the annular conductive rods 31, 32, 33, thereby greatly reducing the downtime of the packaging machine 1.

[0082] Furthermore, since the drive and control device 40 includes a detector device 46, a possible interruption of the current (especially the first DC current) supply due to a failure of the sliding electrical contact device 10, caused by wear and / or dirt on the contact brush 20 and / or the annular conductive rods 31, 32, 33, can be detected and recorded during the operation of the packaging machine 1.

[0083] Based on data relating to the frequency and duration of such current supply interruptions, maintenance work on the brush assembly 11 and / or the conductive rod assembly 12 can be scheduled to clean and / or replace the contact brush 20 and the annular conductive rods 31, 32, 33.

[0084] The present invention also relates to a method of packaging a film 50 or a packaged load 100 of plastic and / or paper material using a packaging machine 1, the packaging machine 1 comprising: a movable ring 4 rotatably supported by a support bracket 3, particularly movable along the working direction W on a main frame 2, and rotatable about a packaging axis X; an unfolding unit 5 fixed to the movable ring 4 and provided with a reel 51 of the film 50; and a sliding electrical contact device 10 for supplying current to the unfolding unit 5 and / or exchanging electrical signals with the unfolding unit 5. The method further comprises: - A possible interruption of the current supply during the operation of the packaging machine 1 is detected and recorded by a detector device 46 connected to the brush device 11 of the sliding electrical contact device 10; - Based on the data, data related to the interruption of current supply is transmitted to the central control unit 60 of the packaging machine to perform maintenance work on the sliding electrical contact device 10.

[0085] The method also includes detecting and recording the frequency and duration of current interruptions via detector device 46. The current, particularly a first current, especially a low-voltage direct current, powers drive and control device 40, which is configured to drive and control at least one electric motor 37, 38 for driving the pre-stretch rollers 62, 53 of the unfolding unit 5, and a sensor device 39 of the unfolding unit 5 suitable for detecting its operating parameters.

Claims

1. A packaging machine (1) for packaging a load (100) with a film or strip (50) of plastic and / or paper material, said packaging machine (1) comprising: -Main frame (2); - Support bracket (3), which is slidably supported by the main frame (2) and is movable in the working direction (W); - A movable ring (4), which is rotatably supported by the support bracket (3) and is capable of rotating about a packaging axis (X) parallel to the working direction (W); - Unfolding unit (5), the unfolding unit (5) is fixed to the moving ring (4), and the unfolding unit (5) is provided with a roll (51) of film (50), a pre-stretching roller (52, 53) for unfolding and pre-stretching the film, and at least one electric motor (37, 38) for rotating the pre-stretching roller (52, 53). - A sliding electrical contact device (10) for supplying current to the deployment unit (5) and / or exchanging electrical signals with the deployment unit (5), the sliding electrical contact device (10) includes a brush device (11) fixed to the moving ring (4) and a conductive rod device (12) fixed to a support ring (6) connected to the support bracket (3), in operation configuration (A), the brush device (11) slides against the conductive rod device (12) to receive current and / or exchange electrical signals; The packaging machine (1) is characterized in that it includes a drive and control device (40) fixed to the moving ring (4) and electrically connected to the brush device (11) and the unfolding unit (5) to drive and control at least the at least one electric motor (37, 38), the drive and control device (40) including a detector device (46) connected to the brush device (11) to receive current from the brush device (11), and the detector device (46) being configured to detect and record possible interruptions in the current supply during operation of the packaging machine (1).

2. The packaging machine (1) according to claim 1, wherein, The detector device (46) is configured to detect and record the frequency and duration of the interruption of the current.

3. The packaging machine (1) according to claim 1 or 2, the packaging machine (1) includes a central control unit (60) configured to receive data related to the interruption of current supply from the detector device (46), and the central control unit (60) configured to determine maintenance work for the brush device (11) and / or the conductive rod device (12) based on the data.

4. The packaging machine (1) according to claim 1 or 2, wherein, The drive and control device (40) includes at least an inverter (42) and a local control unit (43) for driving and controlling the operation of the at least one electric motor (37, 38).

5. The packaging machine (1) according to claim 3, wherein, The drive and control device (40) includes at least an inverter (42) for driving and controlling the operation of the at least one electric motor (37, 38) and a local control unit (43), wherein the detector device (46) is connected to the local control unit (43) to transmit data related to the interruption of the current supply to the local control unit (43), and the local control unit (43) is connected to the central control unit (60).

6. The packaging machine (1) according to claim 5, wherein, The drive and control device (40) includes a wireless transceiver device (44) for connecting the local control unit (43) to an additional wireless relay device (61) of the central control unit (60) of the packaging machine (1).

7. The packaging machine (1) according to any one of claims 1, 2, 5 or 6, the packaging machine (1) comprising at least one backup battery (45) connected to the brush device (11) to receive a first current, and the at least one backup battery (45) connected to the drive and control device (40) so as to continuously power the drive and control device with the first current even in the event of an interruption in the supply of the first current due to a failure of the sliding electrical contact device (10).

8. The packaging machine (1) according to any one of claims 1, 2, 5 or 6, wherein, The unfolding unit (5) includes a sensor device (39) for detecting the operating parameters of the unfolding unit (5).

9. The packaging machine (1) according to claim 7, wherein, The deployment unit (5) includes a sensor device (39) for detecting operating parameters of the deployment unit (5), wherein the sensor device (39) is connected to the backup battery (45) to continuously receive a first current, and the sensor device (39) is connected to the local control unit (43) of the drive and control device (40) to transmit signals related to the detected operating parameters of the deployment unit (5).

10. The packaging machine (1) according to any one of claims 1, 2, 5, 6 or 9, the packaging machine (1) comprising a housing (41) adapted to house the drive and control device (40) and fixed to the moving ring (4).

11. The packaging machine (1) according to any one of claims 1, 2, 5, 6 or 9, wherein, The conductive rod device (12) includes a plurality of annular conductive rods (31, 32, 33) which are parallel to each other and adjacent to each other and fixed to the outer sidewall (16) of the support ring (6), and wherein the brush device (11) includes a plurality of contact brushes (20), each of the plurality of contact brushes (20) being configured to slidably abut against the corresponding annular conductive rod (31, 32, 33).

12. The packaging machine (1) according to claim 11, wherein, Each contact brush (20) is removably attached to the moving ring (4).

13. The packaging machine (1) according to claim 2, wherein, The current is a first current supplied by the first annular conductive rod (31) of the conductive rod device (12).

14. The packaging machine (1) according to claim 4, wherein, The local control unit (43) is powered by a first current supplied by the first annular conductive rod (31) of the conductive rod device (12), and the electric motors (37, 38) are powered by a second current supplied by the second annular conductive rod (32) of the conductive rod device (12).

15. The packaging machine (1) according to claim 14, wherein, The first current is low-voltage direct current, and the second current is three-phase alternating current.

16. The packaging machine (1) according to claim 10, wherein, The housing (41) is fixed to the moving ring (4), opposite to the unfolding unit (5), and facing the unfolding unit (5).

17. The packaging machine (1) according to claim 12, wherein, Each contact brush (20) can be interchanged with another identical contact brush (20).

18. A method for packaging a load (100) with a film or strip (50) of plastic and / or paper material by means of a packaging machine (1), said packaging machine (1) comprising: The movable ring (4) is rotatably supported by the support bracket (3) and is capable of rotating about the packaging axis (X); An unfolding unit (5) fixed to the moving ring (4) and provided with a spool (51) of at least one membrane (50); a sliding electrical contact device (10) for supplying at least one current to the unfolding unit (5) and / or exchanging electrical signals with the unfolding unit (5), the method comprising: - A possible interruption of the supply of at least one current during the operation of the packaging machine (1) is detected and recorded by a detector device (46) connected to a brush device (11) of a sliding electrical contact device (10); - Transmit the data related to the interruption of the current supply to the central control unit (60) of the packaging machine (1). - Based on the data, determine the maintenance work for the sliding electrical contact device (10).

19. The method according to claim 18, further comprising: The detector device (46) detects and records the frequency and duration of the current supply interruption.

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