Self-propelled packaging machine and packaging method

Abstract

A self-propelled wrapping machine (1) movable on a support plane (P) for wrapping a load (100) with a film (50), comprising a self-propelled carriage (2) and a column (3) fixed to said carriage (2) and slidably supporting a unwinding unit (4) provided with a reel (51) of film (50); an anchoring element (30) provided with locking means (35) operable selectively in a closed position (C) or in an open position (A) to fasten or release an initial flap (50a) of the film unwound from the reel (51); a first clamping unit (5) adapted to position and release the anchoring element (30) in an initial step of the wrapping cycle, so that the initial flap (50a) of the film fastened by the locking means (35) is arranged on the support plane (P) adjacent to the load (100), and adapted to grasp and lift the anchoring element (30) and activate the locking means (35) in the open position (A) after the self-propelled wrapping machine (1) has traveled around the load (100) at least once while wrapping the load (100) with the film (50), in order to release the initial flap (50a) of the film.

Description

Field of the Invention

[0001] The present invention relates to a mobile or self-propelled wrapping machine arranged to wrap a film made of plastic material around a load consisting of a product or group of products arranged on a pallet. The present invention also relates to a wrapping method implemented by the above self-propelled wrapping machine. Background Art

[0002] Self-propelled wrapping machines, also known as self-propelled wrapping robots, are machines typically used for wrapping loads of variable shape and size with limited production volumes, usually in environments or rooms where a fixed or static wrapping machine cannot be used due to overall dimensions and / or available space. The load is usually formed by a pallet on which a set of more or less regularly overlapping products and / or objects, even of different sizes and formats, are arranged.

[0003] In other cases, the wrapping, usually for protection purposes, directly concerns products which are usually of large dimensions.

[0004] The self-propelled wrapping machine includes a trolley or carriage supporting a vertical column along which a film unwinding or supply unit can move alternately in a straight line. The film unwinding or supply unit houses a roll of plastic film and is usually provided with a plurality of rollers for unwinding and pre-stretching the film. More precisely, the unwinding unit is provided with a pair of pre-stretching rollers arranged to unwind the film from the reel and pre-stretch or extend the film by a predetermined percentage, and with one or more turning rollers to turn the film towards the load.

[0005] The carriage is usually provided with motorized rear drive wheels and a front drive means including one or more steering wheels operated by a steering gear. The steering gear can be operated by an operator via a guide rod to manually drive the machine in a maneuvering configuration, or by a detection element capable of following the external profile or shape of the load in an operating working configuration, in which the self-propelled machine rotates autonomously and automatically around the load to wrap the load with the film.

[0006] The combination of the alternating linear movement of the unwinding unit along the vertical column and the rotation of the self-propelled machine around the load allows the film to be wrapped around the load, thus forming a series of intertwined strips or bands. The plastic film is wrapped to completely enclose all sides of the load.

[0007] The detection element includes an arm extending laterally outwards relative to the carriage and provided at its end with a idler wheel capable of following the external profile of the load to be wrapped. The detection element exerts a predetermined elastic pressure or thrust on the load to maintain contact with the above load and allows the machine to reliably move around the load along a trajectory determined by the profile of the load itself.

[0008] Self-propelled wrapping machines are also known that include sensors instead of detection elements, such as ultrasonic sensors, capable of detecting the outer surfaces and edges of the load and processing the relevant signals, which signals allow the control unit of the wrapping machine to calculate the wrapping path around the load and avoid collisions. More precisely, based on the outer surfaces and edges of the load detected by the sensors, the control unit controls the steering wheels and / or drive wheels of the carriage so as to steer and drive the carriage around the load.

[0009] In the two known types of self-propelled wrapping machines described above, although the wrapping steps are carried out in a substantially automatic manner, i.e., without manual intervention by the operator, the operator is required both in the initial and final steps of the wrapping process, where in the initial step the initial flanging of the film is fixed to the load or the underlying pallet, and in the final step the film is cut and separated from the reel.

[0010] Therefore, a drawback of the aforementioned known self-propelled wrapping machines is that they cannot perform the wrapping process in a fully automated manner, i.e., without any manual intervention by the operator. Summary of the Invention

[0011] An object of the present invention is to improve the known self-propelled wrapping machine, which is arranged to wrap a load with a stretchable plastic film.

[0012] Another object is to provide a self-propelled wrapping machine that allows the load to be wrapped with a film in a fully automatic manner without any manual intervention by the operator.

[0013] Another object is to provide a self-propelled wrapping machine that allows a firm and stable wrapping to be made.

[0014] A first aspect of the present invention provides a self-propelled wrapping machine according to claim 1.

[0015] A second aspect of the present invention provides a wrapping method according to claim 14. Brief Description of the Drawings

[0016] The present invention can be better understood and implemented with reference to the accompanying drawings, which show exemplary and non-limiting embodiments of the present invention, in which:

[0017] Figure 1 is a perspective view of a self-propelled wrapping machine associated with a load to be wrapped, the load being partially depicted in the initial step of the wrapping cycle;

[0018] Figure 2 is Figure 1 an enlarged partial detail view of

[0019] Figure 3 showing the first clamping unit of the machine of the present invention in a retracted configuration;Yes Figure 1 Partial enlarged view of the machine in the positioning step of the anchoring element, with the initial flanging of the film associated with the anchoring element;

[0020] Figure 4 Yes Figure 3 Enlarged partial detail view showing the first clamping unit of the machine of the present invention in the clamping / release configuration of the anchoring element;

[0021] Figure 5 Yes Figure 1 Another enlarged partial perspective view of the machine, with some components removed to better illustrate the first clamping unit in the film clamping / release configuration and the second clamping unit in the rest position;

[0022] Figure 6 Is a Figure 5 Partial perspective view of the machine from a different angle, with some components removed to better illustrate the clamping unit;

[0023] Figure 7 And Figure 8 Are enlarged front views of the anchoring element with the film locking device in the open position and the closed position respectively.

[0024] Figure 9 Yes Figure 1 Partial enlarged view of the machine in the release step of the anchoring element;

[0025] Figure 10 Yes Figure 1 Partial enlarged view of the machine in the clamping and cutting steps of the film;

[0026] Figure 11 Yes Figure 10 Enlarged partial detail view particularly showing the second clamping unit in the clamping and cutting position;

[0027] Figure 12 Yes Figure 6 Enlarged detail view showing the clamping and cutting device of the second clamping unit;

[0028] Figure 13 Is a partial perspective view showing the first clamping unit in the retracted configuration and the second clamping unit in the film transfer position. Detailed Description of the Invention

[0029] Refer to Figures 1 to 13, shows a self-propelled wrapping machine 1 according to the present invention, which can move around a load 100 on a support plane P (such as the floor or ground of a production site) to wrap the load 100 with a film 50 made of plastic material (especially a film of the cold-extendable type) during a wrapping cycle. The load 100 consists, for example, of one or more products arranged on a pallet.

[0030] The self-propelled wrapping machine 1 includes a self-propelled or mobile carriage 2 and a column 3 fixed to the carriage 2 and slidably supporting a unwinding unit 4. The unwinding unit 4 is provided with a reel 51 of the film 50 and roller devices 41, 42, 43 for unwinding and pre-stretching the film 50. The column 3 is substantially vertical.

[0031] The self-propelled wrapping machine 1 further includes a first clamping unit 5 and a second clamping unit 7, both fixed to the rear support frame 20 of the carriage 2. The self-propelled wrapping machine 1 also includes a movable anchoring element 30 to which an initial flap 50a of the film unwound from the reel 51 can be detachably fixed. More precisely, the anchoring element 30 is provided with locking means 35 which can be selectively operated, respectively, in a closed position C or an open position A to fasten or release the initial flap 50a of the film. The initial flap 50a of the film is produced during a previous wrapping cycle carried out by the self-propelled wrapping machine or is manually unwound from a new reel 51 by an operator.

[0032] The carriage 2, in particular the rear support frame 20, also includes a housing 22 which is adapted to receive and support the anchoring element 30 when the self-propelled wrapping machine 1 is not in operation or during the wrapping step of the load 100, as better explained in the following description.

[0033] The first clamping unit 5 supported by the carriage 2 (in particular through the support frame 20) is movable and adapted to position and release the anchoring element 30 which is associated with the initial flap 50a of the film and which, in an initial step of the wrapping cycle of the load, is fastened by the locking means 35 in the closed position C to the support plane P adjacent to the load 100. The first clamping unit 5 is also adapted to grasp and lift the anchoring element 30 and operate the locking means 35 in the open position A in order to release the initial flap 50a of the film after the self-propelled wrapping machine 1 has traveled around the load 100 for at least one turn to wrap the load 100 with the film 50 provided by the unwinding unit 4, that is, after the film 50 has been partially wrapped and thus fixed to the above-mentioned load 100.

[0034] The second clamping unit 7 supported by the carriage 2 (in particular by the support frame 20) is movable and configured to cut a portion of the film 50 included between the load 100 and the unwinding unit 4 in the last step of the packaging cycle, in order to retain the new initial flap 50a of the film made by cutting the portion of the film 50 and transfer the new initial flap of the film to the anchoring element 30 positioned in the housing 22 for fastening by the locking device 35.

[0035] The first clamping unit 5 includes a first clamping device 6 configured to grasp and fasten the anchoring element 30. The first clamping unit 5 is movable between a retracted configuration R and a clamping / releasing configuration G, in which the first clamping device 6 is adjacent to the carriage 2 in the retracted configuration R and spaced from the carriage 2 and adjacent to the support plane P in the clamping / releasing configuration G, in particular for grasping or releasing the anchoring element 30 positioned on the support plane P.

[0036] The first clamping unit 5 includes a first arm 15 and a second arm 16. The first arm 15 is slidably connected to the carriage 2 and movable along a first operating direction H, in particular substantially parallel to the support plane P. The second arm 16 is connected to the support end 15a of the first arm 15 and is extendable / retractable along a second operating position V, in particular substantially perpendicular to the support plane P, and supports the first clamping device 6.

[0037] The first arm 15 is slidably supported by a pair of guide brackets 23 fixed to the rear support frame 20 and is moved between a retracted position and an extended position along the first operating direction H by a first drive device 24, 25, 26, 27, in which its support end 15a is respectively closer to and spaced farther from the carriage 2.

[0038] The first drive device includes, for example, a first electric motor 24 fixed to the support frame 20, and the first electric motor 24 drives a pinion 25 meshing with a rack 26 fixed to the first arm 15 through a first speed reducer 27. When driven by the first electric motor 24, the rotating pinion 25 moves the rack 26 in two opposite directions and thus linearly moves the first arm 15 along the first operating direction H.

[0039] The second arm includes, for example, a rod 16 slidably supported by a support guide 37 fixed to the support end 15a of the first arm 15. The second clamping device 6 is fixed to the operating end 16a of the rod 16.

[0040] The rod 16 is moved along a second operating position V by a second drive device 28, 29, 39. The second drive device includes an elastic device 28 which is arranged to push and hold the rod or the second arm 16 in a maximum extension configuration, in which the first clamping device 6 is further spaced apart from the support guide 37. The second drive device further includes a first electric motor 29 which is fixed to the support end 15a of the first arm 15 and is connected to and acts on the first clamping device 6 via a flexible element 39 to move the rod 16 against the first elastic device 28, i.e., to move the first clamping device 6 closer to the support guide 37.

[0041] The elastic device 28 includes, for example, a coaxial spring mounted on the rod 16 between the support guide 37 and the clamping device 6, and the flexible element 39 includes, for example, a metal cable.

[0042] Alternatively, the second drive device may include a linear electric actuator which is adapted to support and move the first clamping device 6 in two directions along the second operating direction V.

[0043] The second drive device 28, 29, 39 is configured to move the second clamping device 6 along the second operating position V between a raised position S and first and second lowered positions D1, D2, in which raised position S the second clamping device 6 is further away from the support plane P, and in which first and second lowered positions D1, D2 the second clamping device 6 is closer to the support plane P( Figure 2 and Figure 3 ).

[0044] More precisely, in the retracted configuration R of the first clamping unit 5, the rod 16 and the first clamping device 6 are positioned by the second drive device in the first lowered position D1 in order to position the anchoring element 30 in the housing 22. In the clamping / release configuration G of the first clamping unit 5, the first clamping device 6 is positioned in the second lowered position D2 in order to release the anchoring element 30 onto or remove it from the support plane P.

[0045] In the lowered positions D1, D2, the second drive device 28, 29, 39 can be further activated to move the first clamping device 6 towards the support plane P with a stroke of limited amplitude and then return to the first or second lowered position D1, D2 in order to operate the locking device 35 of the anchoring element 30 and bring it to the open position A or the closed position C, as better explained in the following description.

[0046] The first clamping device 6 includes, for example, a sleeve or bushing 60 and an electromagnet device 61. The sleeve or bushing 60 is provided with a cavity adapted to receive the clamping portion 31a of the locking element 30, and the electromagnet device 61 is particularly associated with the sleeve 60 and can be selectively activated or deactivated respectively to grip or release the clamping portion 31a made of ferromagnetic material.

[0047] The plate 62 is fixed to the sleeve 60, the helical spring 28 abuts against the plate 62 and the flexible element 39 is fixed to the plate 62.

[0048] The sensor device 65 is associated with the first clamping device 6 and is arranged to detect the presence of the anchoring element 30 and its correct positioning relative to the first clamping unit 5 and / or the first clamping device 6 of the self-propelled wrapping machine 1. The sensor device 65 is fixed to the plate 62 by means of a bracket 64.

[0049] Specific reference Figure 7 and Figure 8 , the anchoring element 30 includes a central pin 31 having a first end which forms a clamping portion 31a adapted to be grasped and held by the first clamping unit 5 (in particular the first clamping device 6), and the anchoring element 30 further includes a first plate 33 adapted to abut against a support plane P and slidably connected to the opposite second end of the central pin 31.

[0050] The locking device 35 includes a second plate 34 which is superposed on the first plate 33 and fixed to the central pin 31 and which moves between a closed position C and an open position A, in which closed position C it abuts against the first plate 33, in particular pressing the initial flange 50a of the film against it, and in which open position A it is spaced apart from the first plate 33, in particular releasing the initial flange 50a of the film.

[0051] The locking device 35 further includes a locking / unlocking mechanism 36 of a known type which is disposed between the central pin 31 and the first plate 33 and is configured to switch the position of the second plate 34 between the open position A and the closed position C when the central pin 31 and the second plate 34 are pushed against the first plate 33 by the first clamping unit 5 (more precisely by the first clamping device 6).

[0052] The anchoring element 30 has a total weight of for example at least 3.5 kg to ensure that during the first lap of wrapping the film 50 around the load 100 using the self-propelled wrapping machine 1, the initial flange 50a of the film is held in a given position on the support plane P without moving.

[0053] The second clamping unit 7 includes a second clamping device 8 adapted to grasp and hold the film 50 and a cutting device 9 adapted to cut the film 50.

[0054] The second clamping unit 7 is movable between a clamping and cutting position B1, a transfer position B2 and a rest position B3.

[0055] In the clamping and cutting position B1, the cutting device 9 and the second clamping device 8 are respectively spaced apart from the carriage 2 to cut a portion of the film 50 included between the unwinding unit 4 and the load 100, and to grasp and fasten the new initial flange 50a of the film generated by cutting the film 50. In the transfer position B2, the cutting device 9 and the second clamping device 8 are adjacent to the carriage 2 and the anchoring element 30 positioned in the housing 22 of the carriage 2, so as to transfer the new initial flange 50a of the film to the locking device 35 of the anchoring element 30 arranged in the open position A. In the rest position B3, the cutting device 9 and the second clamping device 8 are adjacent to the carriage 2 and spaced apart from the housing 22, in particular so as not to interfere with the wrapping of the film 50 around the load and the movement of the first clamping unit 5.

[0056] The second clamping unit 7 includes a third arm 17 having a respective first end 17a connected to the carriage 2 and a respective second end 17b supporting the second clamping device 8 and the cutting device 9. The third arm 17 is, for example, rotatably connected to the carriage 2 and is movable along a curved path through the clamping and cutting position B1, the transfer position B2, and the rest position B3.

[0057] The third driving devices 38, 39 fixed to the carriage 2 are arranged to rotate the third arm 17 between the clamping and cutting position B1, the transfer position B2, and the rest position B3.

[0058] The third driving device includes, for example, a second electric motor 38 fixed to the support frame 20 and driving the third arm 17 to rotate about a vertical axis through a second speed reducer 39.

[0059] The second grasping device 8 includes, for example, a gripper having a film locking mechanism 81, which is mechanically operated, in particular mechanically operated by the film 50 itself in the closed position and mechanically operated by a support 82 of the support frame 20 fixed to the carriage 2 in the open position, as better explained in the following description.

[0060] The cutting device 9 includes, for example, a fixed "V"-shaped blade.

[0061] The unwinding unit 4 includes frame means adapted to support a reel 51 and roller devices 41, 42, 43, and the devices 41, 42, 43 are arranged to unwind the film 50 from the reel 51, pre-stretch, and turn the film towards the load 100. More precisely, the roller device includes a pair of pre-stretching rollers 41, 42 and one or more guide rollers 43. The pair of pre-stretching rollers 41, 42 includes a first pre-stretching roller 41 and a second pre-stretching roller 42, which rotate at different speeds about their respective longitudinal axes to stretch or extend the film 50 during unwinding from the reel 51 before wrapping the load 100.

[0062] The unwinding unit 4 further includes a folding device 13 which is adapted to laterally roll up and / or narrow the film 50 exiting from the roller devices 41, 42, 43, so as to reduce the width or its size of the band or to form a rolled-up or pleated portion and to form a cord or strip etc. of the film. The film 50 being pleated or rolled up to form a cord or strip can be more firmly grasped by the second clamping device 8 and is more easily cut by the cutting device 9 of the second clamping unit 7 to form two initial flanges 50a and a terminal flange 50b.

[0063] The carriage 2 includes two or more drive wheels 21, steering wheels and guiding means 10 for guiding the self-propelled wrapping machine 1 along a wrapping path around the load 100. More precisely, the self-propelled wrapping machine 1 is provided with a pair of rear drive wheels 21 and a front steering wheel, wherein at least one of the rear drive wheels is driven by a motor device.

[0064] In the embodiment shown in the figure, the guiding means 10 includes a detecting arm 11 of a known type, which is arranged to follow the outer contour of the load 100 during the wrapping step and is connected to the steering wheel to manipulate the steering wheel and move the carriage 2 along the wrapping path.

[0065] Alternatively, in a variant of the self-propelled wrapping machine 1 not shown, the self-propelled wrapping machine 1 may include sensors capable of detecting the outer surface and edges of the load 100 and processing the relevant signals, and a control unit which is adapted to receive said signals from the sensors, calculate a wrapping path to avoid collision with the load 100, and control the guiding means 10 to guide the self-propelled wrapping machine 1 along the wrapping path. In this variant, the guiding means 10 includes actuating means controlled by the control unit and arranged to manipulate the steering wheel or drive means also controlled by the control unit and arranged to vary the speed of the drive wheels 21.

[0066] The control unit of the self-propelled wrapping machine 1 is also arranged to operate and control the movement of the carriage 2 around the load 100, the supply of the film 50 from the unwinding unit 4, its movement 3 in the vertical direction, and the operation of the clamping units 5, 7 in a coordinated manner in different steps of the wrapping cycle.

[0067] The self-propelled wrapping machine 1 is also provided with sensor means of a known type, for example including a photocell or a capacitance sensor etc., capable of detecting the overall dimensions and size of the load 100 and the distance between the load and the self-propelled wrapping machine 1 during operation. The signals of the sensor means are sent to the control unit of the machine to allow the correct execution of the different steps of the wrapping cycle.

[0068] In operation, the self-propelled wrapping machine 1 of the present invention performs a wrapping cycle of the load 100 according to the following steps.

[0069] In a first initial step, the self-propelled wrapping machine 1 is positioned next to the load 100 and is thus activated to move around the load 100 for at least one full turn in order to calculate and identify a defined initial position W from which the wrapping cycle starts. More precisely, thanks to the sensor means for detecting the overall dimensions and size of the load 100, the control unit is able to stop the self-propelled wrapping machine at the defined initial position W.

[0070] The first clamping unit 5 is arranged in the retracted configuration R and the first clamping device 6 engages with the clamping portion 31a of the anchoring element 30 which is arranged in the housing 22 of the support frame 20 of the carriage 2. More precisely, the first arm 15 is arranged in the retracted position R and the second arm 16 is arranged in the first lowered position D1 such that the clamping portion 31a of the anchoring element 30 is inserted into the sleeve 60 of the first clamping device 6.

[0071] The anchoring element 30 is associated with the initial flap 50a of the film unwound from the reel 51, obtained, for example, by cutting the film at the end of the previous wrapping cycle. In particular, the initial flap 50a of the film is held by the locking device 35 arranged in the closed position C, i.e., fastened between the two plates 33, 34 of the anchoring element 30.

[0072] In a second step, the first clamping device 6 is operated to grasp and fasten the anchoring element 30 and the first clamping unit 5 moves from the retracted configuration R to the clamping / release configuration G in which the first clamping device 6 is adjacent to the load 100 and the support plane P in order to release the anchoring element 30 onto the support plane P, to which the initial flap 50a of the film is fixed.

[0073] More specifically, the electromagnet device 61 of the first clamping device 6 is activated in order to grasp and lock the clamping portion 31a of the anchoring element 30 and the second arm 16 is moved by the second drive means 28, 29, 39 so as to move the first clamping device 6 from the first lowered position D1 to the raised position S in order to lift the anchoring element 30 out of the housing 22. For this purpose, the first motor 29 winds the cable 39 in order to lift the first clamping device 6 by means of the compression spring 28. The first arm 15 is then moved by the first drive means 24, 25, 26, 27 in the retracted position and the extended position along the first operating direction H and then the second arm 16 is moved by the second drive means 27, 28, 39 in order to move the first clamping device 6 from the raised position S to the second lowered position D2 in order to place the anchoring element 30 down onto the support plane P. For this purpose, the first motor 29 partially and limitedly releases the cable 39 in order to allow the spring 28 to lower the first clamping device 6.

[0074] In the third step, the anchoring element 30 that holds the initial flange 50a of the film is released by the first clamping unit 5. More precisely, the electromagnet device 61 of the first clamping device 6 is deactivated to allow the sleeve 60 to disengage from the clamping portion 31a of the anchoring element 30.

[0075] Then the first clamping unit 5 returns from the clamping / release configuration G to the retracted configuration R.

[0076] In the fourth step, the self-propelled wrapping machine 1 moves around the load 100 for at least one full turn in order to wrap the load with the film 50 provided by the unwinding unit 4. The film 50, whose initial flange 50a is fixed to the anchoring element 30, is thus wrapped and firmly adhered and fastened to the load 100. The film 50 is supplied by the unwinding unit 4 at full height, i.e., without being rolled up or laterally narrowed.

[0077] In the fifth step, the self-propelled wrapping machine 1 stops at a defined initial position W to allow the first clamping unit 5 to grasp and lift the anchoring element 30 from the support plane P after the operating locking device 35 has been moved to the open position A, in order to disengage the initial flange 50a of the film from the anchoring element 30. More precisely, when the self-propelled wrapping machine 1 stops, the first clamping unit 5 moves from the retracted configuration R to the clamping / release configuration G, in which the first clamping device 6 is adjacent to the load 100 and the support plane P and is able to grasp the anchoring element 30 and operate the locking device 35 to open. To this end, the first clamping device 6 is moved by the first drive devices 28, 29, 39 to the second lowered position D2 in order to engage the sleeve 60 in the clamping portion 31a and fasten it by activating the electromagnet device 61. The first clamping device 6 is further lowered and then returns to the second lowered position D2 to operate the locking / unlocking mechanism 36 of the anchoring element 30, which causes the second plate 34 of the locking device 35 to move to the open position A, in which the initial flange 50a of the film can be disengaged.

[0078] Then the first clamping unit 5 lifts the anchoring element 30 from the support plane P. The anchoring element 30 is disengaged from the initial flange 50a of the film and the locking device 35 is in the open position A, and the anchoring element is transferred to the housing 22 of the support frame 20 of the carriage 2. To this end, the second arm 16 is moved in the second operating direction V by the second drive devices 28, 29, 39 (in particular by the first motor 29 via the cable 39) in order to move the first clamping device 6 from the second lowered position D2 to the raised position S.

[0079] Then the first arm 15 is moved between an extended position and a retracted position along a first operating direction H by a first drive device 24, 25, 26, 27, and then the second arm 16 is moved along a second operating direction V (in particular by a spring 28) by a second drive device 28, 29, 39 so as to move the first clamping device 6 from a raised position S to a first lowered position D1 to place the anchoring element 30 downward in the housing 22 of the carriage 2. The anchoring element 30 has a locking device 35 that is still in an open position A, in which a second plate 34 is spaced apart from a first plate 33.

[0080] In a sixth step, the self-propelled wrapping machine 1 is again activated to move around the load 100 a defined number of turns so as to wrap the load with the film 50 according to a defined wrapping configuration. The wrapping step includes: during the rotation of the carriage 2 around the load 100, the unwinding unit 4 moves alternately along the column 3 while dispensing the pre-stretched film 50 from the unwinding unit 4.

[0081] In the last lap of wrapping, the folding device of the unwinding unit 4 is operated so as to laterally roll up and / or narrow the film 50 leaving the unwinding unit 4. For example, the film 50 is narrowed to form a cord or strip of limited width that can be more firmly grasped and held by the second clamping device 8 and can be more effectively and easily cut by the cutting device 9 of the second clamping unit 7.

[0082] In a seventh step, at the end of the wrapping, the self-propelled wrapping machine 1 stops at a defined final position Z, possibly coinciding with the initial position W, and the second clamping unit 7 is moved from a rest position B3 adjacent to the carriage 2 to a clamping and cutting position B1 by a third drive device 38, 39 to allow the second clamping device 8 and the cutting device 9 to respectively grasp and cut a portion of the film 50 between the unwinding unit 4 and the load 100 and create a new initial flap 50a and a terminal flap 50b associated with the load 100 ( Figure 10 and Figure 11 ). More precisely, during the rotation, the second clamping device 8 and the cutting device 9 intercept and stretch the film 50 so that they mechanically drive the locking mechanism 81 of the gripper of the second clamping device 8 into a closed position and are simultaneously cut by the blade of the cutting device 9, generating a new initial flap 50a held by the locking mechanism 81 and a terminal flap 50b associated with the load 100.

[0083] In the eighth step, the second clamping unit 7 is moved by the third drive devices 38, 39 to the transfer position B2 in order to transfer and release the new initial flange 50a of the film to the locking device 35 of the locking element 30 arranged in the open position A (positioned in the housing 22 of the support frame 20 of the carriage 2). More precisely, by rotating to the transfer position B2, the second clamping unit 7 inserts the initial flange 50a of the film between the two plates 33, 34 of the anchoring element 30, which two plates 33, 34 are spaced apart in the open position A of the locking device 35. Due to the contact of the control lever 83 of the locking mechanism of the gripper 8 with the support 82 fixed to the support frame 20, the locking mechanism 81 is operated to the open position in order to release the film 50.

[0084] The locking device 35 is operated to the closed position C by the first clamping unit 5, further lowering the first clamping devices 6 from the first lowered position D1 and then returning them to the first lowered position D1 in order to operate the locking / unlocking mechanism 36 of the anchoring element 30 to move the second plate 34 of the locking device 35 to the closed position C to press the initial flange 50a of the film against the first plate 33.

[0085] Then, the second clamping unit 7 disengaged from the initial flange 50a of the film returns to the rest position B3 by the third drive devices 38, 39.

[0086] Therefore, the self-propelled packaging machine 1 of the present invention allows the load 100 to be packaged with the film 50 in a fully automatic manner, i.e., without any manual intervention by the operator either in the initial step or in the final step of the packaging cycle, where in the initial step of the packaging cycle, the initial flange 50a of the film must be held during the first turn of the film 50 wrapped around the load 100, and in the final step, the film 50 must be cut and the initial flange of the film resulting from the cut must be held.

[0087] Due to the locking device 35 and its weight, the anchoring element 30 positioned and released by the first clamping unit 5 on the support plane P adjacent to the load 100 allows the initial flange 50a of the film to be firmly and securely held in the initial step of the packaging cycle of the load 100, in which packaging cycle the initial flange 50a of the film is fixed to the load 100 by the same film 50 wound around the load.

[0088] After the film 50 has been properly packaged and fixed to the load 100 by being wrapped at least one turn, the anchoring element 30 is then retrieved by the first clamping unit 5 so as not to interfere with the subsequent packaging steps. These operations are performed completely automatically and are managed by the control unit of the self-propelled packaging machine 1.

[0089] Furthermore, at the end of the packaging cycle, the self-propelled wrapping machine 1 fully automatically performs the operations of gripping and cutting the film 50 to obtain two initial flanges 50a and a terminal flange 50b of the film.

[0090] A method for wrapping a load 100 by means of the self-propelled wrapping machine 1 described and Figures 1 to 13 shown above includes a packaging cycle that includes the following operating steps:

[0091] - Position the self-propelled wrapping machine 1 movable on a support plane P in an initial position W defined near the load 100; (Step 1)

[0092] - By means of a first gripping unit 5, move an anchoring element 30 including a locking device 35, the anchoring element 30 holding the initial flange 50a of the film unwound from the reel 51 of the unwinding unit 4 by means of the locking device 35 operating in a closed position C, and being received in the housing 22 of the carriage 2 of the self-propelled wrapping machine 1, and position the anchoring element 30 on the support plane P near the load 100; (Step 2)

[0093] - Release the anchoring element 30 holding the initial flange 50a of the film on the support plane P by disengaging the first gripping unit 5; (Step 3)

[0094] - Move the self-propelled wrapping machine 1 around the load 100 at least one full turn, wrapping the load with the film 50 provided by the unwinding unit 4; (Step 4)

[0095] - Stop the self-propelled wrapping machine 1 in the defined initial position W, and grasp the anchoring element 30 by means of the first gripping unit 5, disengage the initial flange 50a from the anchoring element by operating the locking device 35 in an open position A, and lift the anchoring element 30 from the support plane P and transfer it to the housing 22; (Step 5)

[0096] - Move the self-propelled wrapping machine 1 around the load 100 a defined number of turns in order to wrap the load 100 with the film 50; (Step 6)

[0097] - Stop the self-propelled wrapping machine 1 in a defined final position Z, and grasp and cut the portion of the film 50 included between the unwinding unit 4 and the load 100 by means of a second gripping unit 7 to produce a new initial flange 50a of the film held by the second gripping unit 7 and a terminal flange 50b of the film associated with the load 100; (Step 7)

[0098] - Transfer and associate the new initial flange 50a of the film to the anchoring element 30 positioned in the housing 22 by means of the second gripping unit 7. (Step 8)

[0099] According to the method of the present invention, the anchoring element 30 holds the initial flange 50a of the film by operating the locking device 35 to the closed position C by the first clamping unit 5, in particular by the first clamping device 6 of the first clamping unit 5, which is also configured to grasp and fasten the anchoring element 30.

[0100] According to the method of the present invention, the first clamping unit 5 disengages the initial flange 50a of the film from the anchoring element 30 by operating the locking device 35 to the open position A, in particular by the first clamping device 6.

[0101] The method further includes moving the self-propelled packaging machine 1 around the load 100 at least one full turn before positioning the self-propelled packaging machine at the defined initial position W in order to calculate and identify the defined initial position W.

[0102] The method further includes laterally winding and / or narrowing the film 50 leaving the unwinding unit 4 before stopping the self-propelled packaging machine 1 at the defined final position Z in order to form a film cord and / or strip of reduced width.

Claims

1. A self-propelled wrapping machine (1) capable of moving around a load (100) on a support plane (P) to wrap the load (100) with a film (50) made of plastic material during a wrapping cycle, comprising a self-propelled carriage (2) and a column (3), said column (3) being fixed to said self-propelled carriage (2) and slidably supporting a unwinding unit (4), said unwinding unit (4) being provided with at least one reel (51) of the film (50), characterized in that, The self-propelled wrapping machine (1) comprises: - an anchoring element (30) provided with locking means (35) which can be selectively operated, respectively, in a closed position (C) or an open position (A) to fasten or release an initial flap (50a) of the film unwound from a reel (51); - a first clamping unit (5) supported by the self-propelled carriage (2), which is movable and adapted to position and release, in an initial step of the wrapping cycle, the anchoring element (30) onto the support plane (P) adjacent to the load (100), the anchoring element (30) being associated with the initial flap (50a) of the film fastened by the locking means (35) arranged in the closed position (C), and adapted to grasp and lift the anchoring element (30) and activate the locking means (35) in the open position (A) after the self-propelled wrapping machine (1) has travelled around the load (100) for at least one turn while wrapping the load (100) with the film (50) provided by the unwinding unit (4), so as to release the initial flap (50a).

2. The self-propelled wrapping machine (1) according to claim 1, comprising a second clamping unit (7) supported by the self-propelled carriage (2), which is movable and configured to cut, in a last step of the wrapping cycle, a portion of the film (50) comprised between the load (100) and the unwinding unit (4), hold a new initial flap of the film made by cutting the portion of the film (50) and transfer the new initial flap of the film to the anchoring element (30) positioned in the housing (22) of the self-propelled carriage (2), so as to be fastened by the locking means (35).

3. The self-propelled packaging machine (1) according to claim 1, wherein, The first clamping unit (5) comprises a first clamping device (6) configured to grasp and hold the anchoring element (30), the first clamping unit (5) being movable between a retracted configuration (R) and a clamping / release configuration (G), in which the first clamping device (6) is adjacent to the self-propelled carriage (2) for positioning the anchoring element (30) into or removing it from the housing (22) of the self-propelled carriage (2), and in which the first clamping device (6) is spaced apart from the self-propelled carriage (2) and adjacent to the support plane (P) for grasping or releasing the anchoring element (30) onto the support plane (P).

4. The self-propelled packaging machine (1) according to claim 3, wherein, The first clamping device (6) comprises an electromagnet device (61) which can be selectively activated or deactivated, respectively, to grasp or release a clamping portion (31a) of the anchoring element (30).

5. The self-propelled packaging machine (1) according to claim 3, wherein, The first clamping unit (5) includes a first arm (15) and a second arm (16). The first arm (15) is slidably connected to the self-propelled carriage (2) and is movable along a first operating direction (H). The second arm (16) is connected to a support end (15a) of the first arm (15) and is extendable / retractable along a second operating position (V), and supports the first clamping device (6).

6. The self-propelled packaging machine (1) according to claim 5, wherein the first operating direction (H) is substantially parallel to the support plane (P), and the second operating position (V) is substantially perpendicular to the support plane (P).

7. The self-propelled packaging machine (1) according to claim 5, comprising a first drive device (24, 25, 26, 27) and a second drive device (28, 29, 39). The first drive device (24, 25, 26, 27) is for moving the first arm (15) between a retracted position and an extended position along the first operating direction (H), in which the support end (15a) of the first arm (15) is respectively closer to and farther from the self-propelled carriage (2). The second drive device (28, 29, 39) is for moving the second arm (16) along the second operating position (V) at least between a raised position (S) and first and second lowered positions (D1, D2), in which the first clamping device (6) is respectively farther from and closer to the support plane (P).

8. The self-propelled packaging machine (1) according to claim 2, wherein, The second clamping unit (7) includes a second clamping device (8) adapted to grasp and hold the film (50) and a cutting device (9) adapted to cut the film (50). The second clamping unit (7) is movable between a clamping and cutting position (B1), a transfer position (B2), and a rest position (B3). In the clamping and cutting position (B1), the cutting device (9) and the second clamping device (8) are respectively spaced apart from the self-propelled carriage (2) for cutting a portion of the film (50) and for grasping and holding the new initial flange of the film resulting from cutting the film. In the transfer position (B2), the cutting device (9) and the second clamping device (8) are adjacent to the self-propelled carriage (2) and to the anchoring element (30) positioned in the housing (22) of the self-propelled carriage (2) for transferring the new initial flange of the film to the locking device (35) of the anchoring element (30). And in the rest position (B3), the cutting device (9) and the second clamping device (8) are adjacent to the self-propelled carriage (2) and spaced apart from the housing (22).

9. The self-propelled packaging machine (1) according to claim 8, wherein, The second clamping unit (7) includes a third arm (17) having a first end (17a) connected to the self-propelled carriage (2) and a second end (17b) supporting a second clamping device (8) and a cutting device (9). The third arm (17) is rotatably connected to the self-propelled carriage (2) and is movable along a curved path through the clamping and cutting position (B1), the transfer position (B2), and the rest position (B3).

10. The self-propelled packaging machine (1) according to claim 2, wherein, The self-propelled carriage (2) includes a rear support frame (20) adapted to support the first clamping unit (5) and the second clamping unit (7), and the rear support frame (20) is provided with a housing (22) adapted to receive and support the anchoring element (30) at least during the packaging step of the load (100). The anchoring element (30) is positioned in or removed from the housing (22) by the first clamping unit (5) arranged in the retracted configuration (R).

11. The self-propelled packaging machine (1) according to claim 2, wherein, The first clamping unit (5) includes a first clamping device (6) configured to grasp and hold the anchoring element (30). The first clamping unit (5) is movable between a retracted configuration (R) and a clamping / release configuration (G). In the retracted configuration (R), the first clamping device (6) is adjacent to the self-propelled carriage (2) for positioning the anchoring element (30) in or removing it from the housing (22) of the self-propelled carriage (2). In the clamping / release configuration (G), the first clamping device (6) is spaced apart from the self-propelled carriage (2) and adjacent to the support plane (P) for grasping or releasing the anchoring element (30) onto the support plane (P). The self-propelled carriage (2) includes a rear support frame (20) adapted to support the first clamping unit (5) and the second clamping unit (7), and the rear support frame (20) is provided with a housing (22) adapted to receive and support the anchoring element (30) at least during the packaging step of the load (100). The anchoring element (30) is positioned in or removed from the housing (22) by the first clamping unit (5) arranged in the retracted configuration (R).

12. The self-propelled packaging machine (1) according to claim 1, wherein, The anchoring element (30) includes a central pin (31) and a first plate (33). The central pin (31) has a first end provided with a clamping portion (31a). The clamping portion (31a) is arranged to be grasped and held by the first clamping unit (5). The first plate (33) is adapted to abut against the support plane (P) and is slidably connected to the opposite second end of the central pin (31). The locking device (35) includes a second plate (34). The second plate (34) is placed on the first plate (33), fixed to the central pin (31) and is movable between a closed position (C) and an open position (A). In the closed position (C), the second plate (34) abuts against the first plate (33) for fastening the initial flange (50a) of the film against the first plate. In the open position (A), the second plate (34) is spaced apart from the first plate (33) for releasing the initial flange (50a) of the film.

13. The self-propelled packaging machine (1) according to claim 12, wherein, The locking device (35) includes a locking / unlocking mechanism (36) inserted between the central pin (31) and the first plate (33), and is configured to switch the position of the second plate (34) between the open position (A) and the closed position (C) when the second plate (34) and the central pin (31) are pushed against the first plate (33) by the first clamping unit (5).

14. The self-propelled packaging machine (1) according to claim 2, wherein, The unwinding unit (4) includes roller devices (41, 42, 43) for pre-stretching and unwinding the film (50) and folding devices (13) for laterally rolling up and / or pleating the film (50) leaving the roller devices (41, 42, 43). The second clamping unit (7) grasps and holds the rolled up and / or narrowed portion of the film (50) contained between the unwinding unit (4) and the load (100) in the last step of the packaging cycle.

15. The self-propelled packaging machine (1) according to claim 1, including sensor means for detecting the dimensions of the load (100) and / or the distance between the load and the self-propelled packaging machine (1) during operation.

16. A method for packaging a load (100) by means of a self-propelled packaging machine (1) according to any one of the preceding claims, including the following steps in a packaging cycle: - Positioning the self-propelled packaging machine (1) movable on a support plane (P) in an initial position (W) defined near the load (100); - Moving, by means of the first clamping unit (5), the anchoring element (30) provided with the locking device (35), which holds the initial flange (50a) of the film unwound from the reel (51) of the unwinding unit (4) by operating the locking device (35) in the closed position (C), and is received in the housing (22) of the self-propelled carriage (2) of the self-propelled packaging machine (1), and positioning the anchoring element (30) on the support plane (P) near the load (100); - Release the anchoring element (30) that holds the initial flange (50a) of the film on the support plane (P) and disengage from the first clamping unit (5); - Move the self-propelled wrapping machine (1) around the load (100) for at least one full turn and wrap the load using the film (50) provided by the unwinding unit (4); - Stop the self-propelled wrapping machine (1) at the defined initial position (W), grasp the anchoring element (30) by the first clamping unit (5), disengage the initial flange (50a) from the anchoring element (30) by operating the locking device (35) in the open position (A), and lift and transfer the anchoring element (30) from the support plane (P) into the housing (22); - Move the self-propelled wrapping machine (1) around the load (100) for a defined number of turns in order to wrap the load using the film (50); - Stop the self-propelled wrapping machine (1) at the defined final position (Z) and grasp and cut the portion of the film (50) contained between the unwinding unit (4) and the load (100) by the second clamping unit (7) in order to obtain a new initial flange of the film held by the second clamping unit (7) and a terminal flange (50b) of the film associated with the load (100); - Transfer and associate the new initial flange of the film to the anchoring element (30) positioned in the housing (22) by the second clamping unit (7).

17. The method according to claim 16, including moving the self-propelled wrapping machine around the load (100) for at least one full turn before positioning the self-propelled wrapping machine (1) at the defined initial position (W) in order to calculate and position the defined initial position (W).

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