CENTRING DEVICE FOR CENTRING A PACKAGING FILM FOR A FORMING UNIT OF A PACKAGING MACHINE

Abstract

A centring device for centring a packaging film for a forming unit of a packaging machine, comprises a support structure connectable to the forming unit; centring elements connected to the support structure and movable between a rest configuration and an active configuration for compressing the packaging film against a guide body of the forming unit; actuation members connected to the centring elements so as to align the packaging film in accordance with a predefined sliding axis thereof. The rest configuration corresponds to a static position whereas the active configuration corresponds to a dynamic position, in which the centring elements are in contact with the film so as to align it with the sliding axis. The centring elements can only be selectively activated under conditions in which the film is skidding with respect to the sliding axis.

Claims

1. A centring device for centring a packaging film for a forming unit of a packaging machine; wherein the forming unit comprises a guide body extending along a sliding axis and is configured to receive the packaging film having a substantially tubular and flattened shape, which comes from a reel placed upstream of the forming unit so as to wrap the guide body, and which slides along the sliding axis, so as to form a plurality of packages; the centring device comprising: a support structure connectable to the forming unit at an inlet area thereof for the packaging film; centring elements connected to the support structure and movable between a rest configuration in which the centring elements are proximal to the support structure, and an active configuration in which the centring elements are distal with respect to the support structure for compressing the packaging film against the guide body of the forming unit; actuation members connected to the centring elements and configured to drive them between the rest configuration and the active configuration; wherein the actuation members are configured to selectively activate at least one of the centring elements from the rest configuration to the active configuration, and exert a force between the packaging film and the centring elements thereof, so as to align the packaging film in accordance with a predefined sliding axis thereof on the forming unit; wherein the rest configuration corresponds to a static position in which the centring elements are inactive and disengaged from the film, while the active configuration corresponds to a dynamic working position in which the centring elements are in contact with the film to press it against a surface of the guide body so as to align it with the sliding axis; and wherein the centring elements are selectively activatable only under conditions of the film skidding with respect to the sliding axis, remaining distal from the film itself during its movement along the sliding axis.

2. The centring device of claim 1, wherein the centring elements are rotatably connected to the support structure and configured to perform an oscillating movement between the rest configuration and the active configuration.

3. The centring device of claim 1, wherein the centring elements comprise a pair of levers which are during use facing each other and arranged astride the sliding axis.

4. The centring device of claim 3, wherein the pair of levers comprises: a first lever extending between a first end in which a first idle roller is rotatably mounted and a second end connected to the actuation members; and a second lever extending between a third end in which a second idle roller is rotatably mounted and a fourth end connected to the actuation members.

5. The centring device of claim 4, wherein the first and second levers are arranged inclined to each other with respect to the sliding axis of the packaging film.

6. The centring device of claim 4, wherein the first and second idle rollers respectively have a rubberised outer surface thereof.

7. The centring device of claim 4, wherein the actuation members comprise a pair of cylinders each connected respectively to the first and second levers.

8. The centring device of claim 7, wherein the pair of cylinders comprises cylinders of the pneumatic type.

9. The centring device according to claim 1, comprising a sensor arranged at the centring device and configured to detect a deviation of the packaging film with respect to the predefined sliding axis.

10. The centring device of claim 9, comprising an electronic control unit connected to the sensor and to the actuation members, and configured to receive a deviation signal from the sensor and send a centring signal to the actuation members to selectively move only one of the centring elements in the active configuration.

11. A forming unit for an automatic packaging machine, comprising: a support frame; an elongated guide body, connected to the support frame, and extending along a sliding axis of a packaging film; a centring device comprising: a support structure connectable to the forming unit at an inlet area thereof for the packaging film; centring elements connected to the support structure and movable between a rest configuration in which the centring elements are proximal to the support structure, and an active configuration in which the centring elements are distal with respect to the support structure for compressing the packaging film against the guide body of the forming unit; actuation members connected to the centring elements and configured to drive them between the rest configuration and the active configuration; wherein the actuation members are configured to selectively activate at least one of the centring elements from the rest configuration to the active configuration, and exert a force between the packaging film and the centring elements thereof, so as to align the packaging film in accordance with a predefined sliding axis thereof on the forming unit; wherein the rest configuration corresponds to a static position in which the centring elements are inactive and disengaged from the film, while the active configuration corresponds to a dynamic working position in which the centring elements are in contact with the film to press it against a surface of the guide body so as to align it with the sliding axis; and wherein the centring elements are selectively activatable only under conditions of the film skidding with respect to the sliding axis, remaining distal from the film itself during its movement along the sliding axis.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Additional features and advantages will appear clearer from the indicative, and therefore not limiting, description of a preferred but not exclusive embodiment of a centring device for centring a packaging film for a forming unit of a packaging machine, as illustrated in the accompanying drawings, wherein:

[0020] FIG. 1 shows, according to a perspective view, a centring device for centring a packaging film in a configuration mounted on a forming unit of a packaging machine, according to an embodiment;

[0021] FIG. 2 shows, according to a longitudinal sectional view, the centring device illustrated in FIG. 1;

[0022] FIG. 3 shows, according to a detailed perspective view, the centring device illustrated in FIG. 1;

[0023] FIG. 4A shows, according to a side view, the centring device illustrated in FIG. 3;

[0024] FIG. 4B shows, according to a front view, the centring device illustrated in FIG. 3;

[0025] FIG. 4C shows, according to a top plan view, the centring device illustrated in FIG. 3.

[0026] It should be noted that the drawings serve solely to illustrate embodiments of the centring device with the aim of better clarifying, in combination with the description, the principles at the basis of the disclosure.

DETAILED DESCRIPTION

[0027] With reference to the attached figures, a centring device for centring a packaging film for a forming unit of a packaging machine has been indicated overall with the number 100.

[0028] In the following description, specific reference will be made to a centring device 100 operatively installed in a forming unit of an automatic packaging machine of the horizontal type (called in the technical jargon of the sector with the acronym HFFS, i.e. Horizontal Form Fill and Seal) and intended to make packages of the square or rectangular bottom type (i.e. stand-up pouch).

[0029] However, the centring device 100 can also be installed in other configurations of packaging machines, for example machines of the vertical type (VFFS, i.e. Vertical Form Fill and Seal) and intended to make various types of packages, without thereby falling outside the scope of protection. The term packaging film shall mean a film in a flexible polymeric material (for example polyethylene, polypropylene, multilayer, and others still commonly used in the technical field and well known to a person skilled in the art) adapted to be suitably folded and heat-sealed, so as to make a sealed closed package containing one or more products of various kinds. In accordance with the embodiment illustrated in the attached figures, the centring device 100 is reversibly mountable on a forming unit 110 of a packaging machine.

[0030] In particular, the forming unit 110 is configured to receive a packaging film F, for example coming from a feeding unit arranged upstream of the forming unit 110 itself, and wherein the feeding unit comprises at least one film reel and film conveying means configured to unwind it and convey it towards an inlet area 10a for the film of the forming unit 110.

[0031] Specifically, the packaging film F is preformed, so as to make a substantially tubular or annular closed shape.

[0032] For example, the packaging film F has a shape of a substantially flattened cross-section thereof, so as to make a shape of the oval or oblong type.

[0033] In other words, the packaging film F is pre-shaped or pre-treated (as mentioned above) in such a way as to have a tubular shape suitable for entering through the inlet area 10a of the forming unit 110, embracing (i.e. wrapping) the guide body 11 like a ring.

[0034] As just mentioned, the forming unit 110 has an inlet area 10a for the packaging film F configured to receive the film, and an outlet area 10b for the film itself, opposite to the inlet area 10a, configured to discharge the formed packaging film downstream (for example towards one or more heat-sealing units with which the packaging machine is equipped).

[0035] The forming unit 110 further comprises a guide body 11 having an elongated shape, extending along a sliding axis Y-Y of the packaging film F between the inlet area 10a and the outlet area 10b.

[0036] The guide body 11 is configured to convey the film itself from the inlet area 10a towards the outlet area 10b of the forming unit 110.

[0037] Preferably, the guide body 11 has a substantially flattened planar shape, in particular conical from the inlet area 10a towards the outlet area 10b; and configured to receive restingly (on at least one of its faces) the packaging film F during its sliding between the inlet and outlet areas 10a, 10b.

[0038] Preferably, the inlet and outlet areas 10a, 10b of the packaging film F are aligned along the sliding axis Y-Y.

[0039] In accordance with the embodiment illustrated in the attached figures, the centring device 100 for centring a packaging film F for a forming unit 110 comprises a support structure 20 reversibly connectable to the forming unit 110 at the inlet area 10a for the packaging film F.

[0040] More specifically, the support structure 20 comprises metal plates 20, in particular at least two metal plates 20a, 20b, mechanically coupled to each other, preferably by a connection of the permanent type, for example by welding.

[0041] As illustrated in detail in FIG. 2, the two metal plates 20a, 20b are arranged connected to each other at ninety degrees, so as to make a bracket for anchoring the centring device 100 to the forming unit 110 (see FIGS. 1 and 2).

[0042] According to one aspect, the centring device 100 is mounted cantilevered on the forming unit 110 (see FIGS. 1 and 2) at the inlet area 10a of the packaging film.

[0043] Preferably, the connection between centring device 100 and forming unit 110 is made by means of threaded elements, for example screws, nuts, washers and the like, so as to allow a disassembly thereof.

[0044] According to this embodiment, the centring device 100 further comprises centring elements 30 connected to the support structure 20 and movable between a rest configuration in which the centring elements 30 are proximal to the support structure 20 (i.e. they are located at a distance close to the support structure 20), and an active configuration in which the centring elements 30 are distal with respect to the support structure 20 (i.e. they are located at an increased distance with respect to the distance in which they are located in the rest configuration) for compressing the packaging film F against the guide body 11 of the forming unit 110.

[0045] In other words, the rest configuration corresponds to a position in which the centring elements 30 are inactive (i.e. a static condition of the centring elements 30), while the active configuration corresponds to a working position (i.e. a dynamic condition of the centring elements 30) in which the centring elements 30 are in contact with the packaging film F by pressing it against a surface of the guide body 11, and wherein the centring elements 30 are selectively activatable only under conditions of the film F skidding with respect to the sliding axis Y-Y, remaining distal from the film itself during its movement along the sliding axis Y-Y.

[0046] In other words, the centring elements 30 have an intermittent operation, i.e. it is activated only under conditions of the film skidding with respect to a predefined direction thereof (i.e. aligned to the sliding axis Y-Y).

[0047] In particular, as introduced in detail below, a first lever 31 or a second lever 32 or both are selectively activated.

[0048] The centring device 100 further comprises actuation members 40 connected to the centring elements 30 and configured to drive them between the rest configuration and the active configuration.

[0049] The actuation members 40 and the centring elements 30 will be described in greater detail below.

[0050] In general, the actuation members 40 are configured to selectively activate at least one of the centring elements 30 from the rest configuration to the active configuration, to modify a friction value between the packaging film F and the centring elements 30 themselves, so as to align the packaging film F in accordance with a predefined sliding axis Y-Y thereof.

[0051] In other words, in the case of the packaging film F skidding along a direction transverse to the sliding axis Y-Y such as to produce a deviation of the advancement direction of the film with respect to an advancement direction thereof substantially parallel to the sliding axis Y-Y, the centring elements 30 selectively act on the packaging film F during an advancement motion thereof along the sliding axis Y-Y, so as to modify a value of a friction force between the film and the centring elements 30 themselves.

[0052] Advantageously, the centring device 100 allows to automatically return the advancement direction of the packaging film F along an advancement direction parallel and aligned with the sliding axis Y-Y, and corresponding to a predefined direction of sliding of the film set by the guide body 110.

[0053] In accordance with the embodiment illustrated in the attached figures, the centring elements 30 are rotatably connected to the support structure 20 and configured to perform an oscillating movement between the rest configuration and the active configuration.

[0054] In other words, the centring elements 30 rotate around a respective centre of rotation 35a, 35b (as described in more detail below) between the rest and active configuration.

[0055] Still in other words, the centring elements 30 perform a tilting movement, that is, completely similar to that of a rocker.

[0056] In accordance with an embodiment which is not illustrated in the attached figures, the movement of the centring elements 30 can be of the translational linear type, for example made by means of any linear movement mechanism well known to a person skilled in the art and therefore not further described.

[0057] In accordance with the embodiment illustrated in detail in FIGS. 2 and 4A-C, the centring elements 30 comprise a pair of levers 31, 32 in use side by side and arranged astride the sliding axis Y-Y.

[0058] In other words, as illustrated in FIGS. 3 and 4C, a first lever 31 is arranged on one side with respect to the sliding axis Y-Y, while a second lever 32 is arranged on the opposite side with respect to the first lever 31, and facing the latter.

[0059] Preferably, the levers 31, 32 are symmetrically spaced with respect to the sliding axis Y-Y and opposite each other.

[0060] More in detail, according to an aspect of the invention, the pair of levers 31, 32 comprises a first lever 31 extending between a first end 31a in which a first idle roller 33a is rotatably mounted and a second end 31b connected to the actuation members 40.

[0061] The pair of levers further comprises a second lever 32 extending between a third end 32a in which a second idle roller 33b is rotatably mounted and a fourth end 32b connected to the actuation means 40.

[0062] Preferably, as mentioned above, the first lever 31 oscillates with respect to its own centre of rotation 35a arranged in an intermediate position between the first and third ends 31a, 32a; while the second lever 32 oscillates with respect to its own centre of rotation 35b arranged in an intermediate position between the second and fourth ends 31b, 32b.

[0063] Preferably, the first and second levers 31, 32 are substantially identical between them.

[0064] Preferably, the first and second idle rollers 33a, 33b are substantially identical between them.

[0065] According to an aspect that is illustrated in FIGS. 4B-4C, the first and second levers 31, 32 are arranged inclined to each other with respect to the sliding axis Y-Y of the packaging film F with the second and fourth ends 31b, 32b at a distance less than a distance between the first and third ends 31a, 32a.

[0066] In other words, in accordance with a top plan view (see FIG. 4C) the first and second levers 31, 32 are arranged in such a way as to realize a conical or wedge-shaped profile.

[0067] Advantageously, the first and second rollers 33a, 33b press the film in an outer portion thereof with respect to the sliding axis Y-Y, and this pressing contact generates a deviation of the film such as to bring it back centred and aligned with the sliding axis Y-Y.

[0068] According to a further aspect, the first and second idle rollers 33a, 33b respectively have a rubberized outer surface thereof.

[0069] In other words, the outer surface of each idle roller 33a, 33b is deformable or yieldable.

[0070] Preferably, the outer surface of each idle roller 33a, 33b is covered with a polymeric material, for example natural or synthetic rubber.

[0071] Advantageously, this rubberized outer surface allows each idle roller 33a, 33b to act on the packaging film F without damaging it, and to exert in contact with the film a value of a friction force such as to deviate the advancement motion of the film.

[0072] According to an aspect, the actuation members 40 comprise a pair of cylinders 41, 42 each connected respectively to the first and second levers 31,32.

[0073] More in detail, the pair of cylinders comprises a first cylinder 41 and a second cylinder 42, preferably substantially identical between them, and arranged mounted, on the centring device 100, along a working direction transverse, preferably orthogonal, to the sliding axis Y-Y (see FIG. 4A). In other words, as illustrated in the attached figures, the first and second cylinders 41, 42 are oriented and act along a direction substantially orthogonal to the movement direction of the packaging film F.

[0074] According to another aspect, the first and second cylinders 41, 42 respectively comprise their own movable end configured to be rotatably connected respectively to the second and fourth ends 31b, 32b of the first and second levers 31, 32.

[0075] The first and second cylinders 41, 42 further comprise respectively a fixed end, opposite the respective movable end, and configured to be rotatably connected to the support structure 20.

[0076] The pair of cylinders 41, 42 preferably comprises cylinders of the pneumatic type.

[0077] In accordance with an embodiment which is not illustrated in the attached figures, the actuation members 40 may comprise electric, hydraulic or other cylinders, well known to a person skilled in the art and therefore not further described.

[0078] In accordance with an embodiment, the centring device 100 comprises a sensor 50 (schematically illustrated in the attached figures) arranged parallel to the sliding axis Y-Y and configured to detect a deviation of the packaging film F with respect to the predefined sliding axis Y-Y.

[0079] In other words, the sensor 50 is mounted on the forming unit 110 at an intermediate position between the inlet area 10a and the outlet area 10b of the packaging film F, parallel to the sliding axis Y-Y. In particular, the sensor 50 is configured to detect a misalignment (or deviation or offsetting) of a position of the packaging film F with respect to a predefined position thereof substantially parallel and aligned with the sliding axis Y-Y during a movement of the film itself along the guide body 11.

[0080] In addition, the sensor 50 is configured to translate this deviation value into an electrical signal to be transmitted to an electronic control unit (introduced and described in more detail below).

[0081] Preferably, the sensor 50 is a photocell.

[0082] In accordance with another embodiment, the centring device 100 further comprises an electronic control unit connected to the sensor 50 and to the actuation members 40, configured to receive the deviation (or misalignment) signal from the sensor 50 and send a centring signal to the actuation members 40 to selectively move only one of the centring members 40 in the active configuration.

[0083] As illustrated in the attached FIGS. 1-4C, the operation of the centring device is as follows.

[0084] The forming unit 110 comprises a guide body 11 extending along the sliding axis Y-Y and is configured to receive the packaging film F; the latter comes from a reel (not illustrated) placed upstream of the forming unit 110, and is preformed so as to make a substantially tubular shape, in particular flattened to wrap the guide body 11 during a sliding thereof along the sliding axis Y-Y, so as to form a plurality of packages.

[0085] If the direction along which the packaging film F slides deviates or is offset with respect to the sliding axis Y-Y, this deviation or offsetting is detected by the sensor 50.

[0086] In fact, this sensor 50 transduces a film deviation or offsetting value into an electrical signal to be sent to the electronic control unit.

[0087] The latter receives the electrical signal from the sensor 50, processes it and transmits a centring signal (proportional to the electrical signal) selectively to control elements, for example pneumatic valves for regulating an air flow, connected respectively to the first and second cylinders 41, 42.

[0088] More in detail, such pneumatic valves (not illustrated in the attached figures) intercept and regulate an air flow coming for example from a centralized compressed air system, towards each first and second cylinder 41, 42 to actuate the movement thereof (i.e. to extend the stem of the selected cylinder along an upward vertical direction-see FIG. 4A).

[0089] The activation of the first and/or second cylinders 41, 42 causes the movement respectively of the first and/or second levers 31, 32 and therefore correspondingly of the first and/or second idle rollers 33a, 33b.

[0090] In this way, the first and/or second idle rollers 33a, 33b selectively compress, against the guide body 11 of the forming unit 110, respective lateral portions (i.e. portions arranged respectively on one side and on the opposite side of the film with respect to the sliding axis Y-Y) of the packaging film 110 during a sliding thereof along the sliding axis Y-Y.

[0091] In this way, the pressing contacts of the first and/or second rollers 33a, 33b produce a friction force on the packaging film F such as to vary its movement direction and re-align the film itself along the sliding axis Y-Y.

[0092] In particular, the first and/or second cylinders 41, 42 are selectively driven as a function of a direction along which the packaging film F deviates with respect to the sliding axis Y-Y.

[0093] Specifically, one of the first and second cylinders 41, 42 that is in a position opposite to a deviation or offsetting direction of the packaging film F with respect to the sliding axis Y-Y is activated.

[0094] A forming unit 110 for an automatic packaging machine is also disclosed, wherein the same numerical references will be maintained for simplicity of exposure.

[0095] Specifically, the forming unit 110 comprises a support frame 10, preferably made of metallic material, and movable in a plane parallel to the ground so as to be associable with a packaging machine.

[0096] The forming unit 110 further comprises an elongated guide body 11, connected to the support frame 10, and extending along a sliding axis Y-Y of a packaging film F.

[0097] The forming unit 110 further comprises a centring device 100 having one or more of the above features.