EP1582462A1

EP1582462A1 - Product banding apparatus

Info

Publication number: EP1582462A1
Application number: EP05425189A
Authority: EP
Inventors: Mauro Cere'
Original assignee: Aetna Group SpA
Current assignee: Aetna Group SpA
Priority date: 2004-04-02
Filing date: 2005-03-31
Publication date: 2005-10-05
Anticipated expiration: 2025-03-31
Also published as: DE602005000452D1; DE602005000452T2; ITBO20040186A1; ES2281067T3; EP1582462B1

Abstract

An apparatus for banding individual, grouped or palletised products comprises: a frame (4) mounted over a conveyor (2) and equipped with two rolls (5, 6) of film mounted on the frame uprights (7, 8) in such a way as to form a band of film (9) positioned transversely relative to the uprights (7, 8) so as to intercept the front of the products (3) as they move forward, thereby unwinding the film (9) from the two rolls (5, 6); a unit (10) for sealing and cutting the film (9), supported by the frame (4) and mobile between an idle position and a working position where the unit (10) moves in such a way as to define a film (9) wrapping cycle comprising the steps of intercepting the film, sealing it and cutting a portion of the film (9) wrapped around the products (3); and, lastly, a unit (11) at least for inspecting the film (9), said unit (11) being associated with the sealing and cutting unit (10) and being designed to come into operation after the step of sealing the film (9) has been completed.

Description

The present invention relates to an apparatus for banding products, in particular, stacked products (such as, for example, but not restricted to, packs of bottles or other containers) to undergo intermediate processes and to be transported from one factory to another or from one processing station to another.
Apparatus of this type is used to wrap a band of material around a group of products (preferably palletised) stacked to a certain height and relatively light in weight, in such a way as to stabilise the stack during its transportation from one processing line to another. The palletised load might consist, for example, of bottle crates placed side by side and stacked in two or more layers.
To stabilise a load of this type, the banding apparatus wraps a first band of plastic film at a certain height in order to hold the stack together at the most unstable part of it which would be the first to topple during transportation.
Prior art machines that perform banding operations of this type comprise a portal frame structure whose uprights mount a pair of film rolls at a predetermined height. The film is unwound by suitable rollers in such a way that it is positioned transversely between the uprights to intercept the palletised load as the pallet moves under the portal frame on a conveyor.
The forward motion of the pallet, after its front end has come into contact with the band of film, causes the rolls to unwind so as to wrap the band around the sides of the products stacked on the pallet. As soon as the pallet has moved past the portal frame, it is stopped and a unit comprising a sealer and a cutter, mounted behind the uprights, runs along the back of the palletised load on suitable supports in a direction parallel to the rear face of the load in such a way that the band of film is wrapped right around the load.
In other words, the film forms a loop around the upper section of the palletised product load and, since the film used is usually stretch film, also has a tightening effect which holds the load together.
At this point, the section of the band at the back of the palletised load is sealed and, as soon as this has been done, the cutter cuts the band half way between the two sealed ends: that means the looped band wrapped around the palletised load is closed, sealed and cut off, while the seal keeps the two rolls joined to each other by the remaining film positioned transversely between the two uprights and ready to intercept the next palletised load moving forward on the conveyor, thus ensuring that the process is not interrupted.
An increasingly frequent requirement is for banding machines to apply to the palletised load a second band of film, lower down than the first and bearing a distinguishing mark, such as, for example, a label identifying the products transported, their factory of origin, or other information.
A new solution for this new type of apparatus has been proposed by the same Applicant as the present (see patent application EP 1.357.031), in which the two sealing and cutting units are supported by a single mounting unit that projects from the portal frame and that slides along the frame crossbeam to and from the idle and working positions of the units: this solution has made the sealing and cutting units extremely, practical and adaptable to any type of production line in which the portal frame is used.
Apparatus of this type is also equipped with a unit for inspecting the band or bands of film applied to the product group and which, if necessary, stops the apparatus if the band of film has not been applied or or has been applied incorrectly.
There are at least two different technical solutions for this unit. The first is a suction cup unit, located near one of the uprights of the portal frame and activated when the banding cycle has been completed; the suction cup unit is moved into contact with the band and applies a vacuum which exerts a pulling action on the film enabling the control system to detect whether the band of film has been applied and, if it has, whether it has been applied correctly.
The second solution is one proposed by the Applicant, again in patent application EP 1.357.031, and is a unit consisting of a hooked rod located, with respect to the product feed direction, behind one of the frame uprights. The rod is inserted between the product stack and the band of film being wound around the products and, once the band has been sealed, exerts a pulling action on the film to check whether it has been applied correctly and is wound tightly around the products.
Both the above solutions, though reliable in terms of functioning, are not free of disadvantages mainly because they slow down the production cycle, since the stack of products has to be stopped in order enable the check to be performed, and because of their high cost, since the apparatus requires two inspection units, one for each of the film bands applied.
The present invention therefore has for an aim to overcome the above mentioned drawbacks through a product banding apparatus that is at once reliable and precise and that is equipped with film inspection units which are reliable, economical and technically integrated into the production cycle so as not to have negative effects on the operation of the apparatus.
According to the invention, this object is achieved by a machine for banding individual, grouped or palletised products and comprising: a frame mounted over a conveyor and equipped with two rolls of film mounted on the frame uprights in such a way as to form a band of film positioned transversely relative to the uprights so as to intercept the front of the products as they move forward, thereby unwinding the film from the two rolls; a unit for sealing and cutting the film, supported by the frame and mobile between an idle position and a working position where the unit moves in such a way as to define a wrapping cycle comprising the steps of intercepting the film, sealing it and cutting a portion of the film wrapped around the products; and, lastly, a unit at least for inspecting the film, said unit being associated with the sealing and cutting unit and being designed to be activated simultaneously with the completion of the cycle of wrapping the film around the products.
The technical characteristics of the invention, with reference to the above objects, are clearly described in the claims below and its advantages are apparent from the detailed description which follows, with reference to the accompanying drawings which illustrate a preferred embodiment of the invention provided merely by way of example without restricting the scope of the inventive concept, and in which:

Figure 1 is a front face view, with some parts cut away to better illustrate others, of a product banding apparatus according to the present invention;
Figure 2 is a partial perspective detail view, with some parts cut away to better illustrate others, showing a sealing and cutting unit;
Figures 3 and 4 are front views showing a detail from Figure 2 in two different working configurations;
Figures 5 to 9 are schematic perspective views illustrating respective operating steps with reference to the sealing and cutting unit of Figures 1 and 2 and the detail of Figures 2 to 4.

With reference to the accompanying drawings, in particular Figure 1, the apparatus disclosed is used for banding individual, grouped or palletised products and, in particular, for banding products stacked to a certain height and relatively light in weight, in such a way as to stabilise the stack during its transportation from one processing line to another. For example, and without restricting the scope of the invention, the apparatus is used for banding palletised loads consisting of bottle crates placed side by side and stacked in two or more layers.
This type of apparatus, labelled 1 in its entirety, is illustrated by way of example in Figure 1 and many of its parts are well known from patent application EP 1.357.031 by the same Applicant and will not therefore be described in detail below.
The apparatus 1 basically comprises:

a conveyor 2 for transporting the products 3 in a direction of feed indicated by the arrow D;
a frame 4 mounted over the conveyor 2 and equipped with at least two rolls 5 and 6 of film mounted on the frame uprights 7 and 8 in such a way as to form a band of film 9 positioned transversely relative to the uprights 7, 8 and intercepted by the front of the products 3 as they move forward in such a way as to unwind the film 9 from the two rolls 5, 6;
at least one unit 10 for sealing and cutting the film 9, supported by the frame 4 and mobile between an idle position, where the unit 10 is close to the uprights 7 and 8, and a working position, where the unit 10 is away from the uprights 7 and 8 so as to define a film wrapping cycle comprising the steps of intercepting the film, sealing it and cutting a portion of the film 9 wrapped around the products 3;
at least one unit 11 which is designed to inspect the portion of film 9 defined during the wrapping cycle and which acts on the film 9 itself.

In particular, the unit 11 for inspecting the film 9 is associated with the sealing and cutting unit 10 and is designed to come into operation after the step of sealing the film 9 has been completed.
More specifically, the unit 11 comes into operation simultaneously with the completion of the cycle of wrapping the film 9 around the products 3.
As may be clearly seen in Figures 5 to 9, the film 9 inspection unit 11 may come into operation when the sealing and cutting unit 10 moves from the working position to the idle position.
Alternatively, the unit 11 might come into operation even before this, when the film 9, sealed and cut by the sealing and cutting unit 10, is released.
To better understand the structure and operating context in which the unit 11 is fitted, again with reference to Figure 1, the apparatus 1 may be equipped with four rolls 5, 6, 5', 6' of film 9, 9', operating in pairs at two different heights, and two separate units 10, 10' for sealing and cutting the respective film 9, 9'.
Further, each unit 10, 10' for sealing and cutting the respective film 9, 9' is divided into two half- parts 12 and 13 each associated with a respective drive beam 14 and 15 for moving it from the idle position to the working position and vice versa.
In an apparatus 1 structured in this way, there may be two units 11 and 11' for inspecting the respective film 9, 9' and associated with the two respective sealing and cutting units 10 and 10'.
Each of the units 11, 11' for inspecting the film 9, 9' may be associated with one of the half- parts 12 and 13 constituting the unit 10 and 10' for sealing and cutting the film 9, 9'.
Looking more closely at the technical details with reference to Figures 2, 3 and 4, each of the film 9, 9' inspection units 11 and 11' comprises a microswitch 16 controlled by a sensor 17 that touches the respective film 9, 9'.
The sensor 17 consists of a rod driven by suitable means 18 on the half- part 12, 13 so that it moves at least between a first idle position in which the contact rod 17 is lowered (see Figures 2, 3 and 5) and a working position in which the rod 17, when the two half- parts 12 and 13 are moved towards each other, is raised between the products 3 and the respective film 9 and 9' being wrapped around them (see Figures 4 and 6).
The rod 17 is also linked to a lever 19 forming part of the drive means 18 and able to rotate freely about at least two axes Z and X (see Figure 2) perpendicular to each other and defining a plane parallel to the feed direction D of the products 3 in such a way that it is initially angled towards the products 3 to an initial position between the sealed film 9, 9' and the products 3 (see Figures 6, 7 and 8) and is then pulled away from the film 9, 9' when the respective half- part 12, 13 moves from the working position to the idle position (see Figure 9).
Returning to the structure of the unit 11, 11', again with reference to Figures 2, 3 and 4, the rod 17 is linked to the lever 19 through a spring 20 which permits the aforementioned free rotation through at least one arc about the two axes Z and X which are perpendicular to each other (see arrows FZ and FX, Figure 2).
The lever 19 is in turn pivoted to one of the two half- parts 12, 13 of the respective sealing unit 10 and 10' and driven by the above mentioned lever 19 drive means 18 from a rest position, in which the lever 19 is parallel to the half part 12 and 13 with the rod 17 in the lowered position (see Figure 3), to a working position, in which the lever 19 is rotated through a predetermined angle α and the rod 17 is in a raised position, that is to say, vertical (see Figure 4 and arrow F18).
The lever 19 is linked at one end of it to a pneumatic actuator 18 constituting the above mentioned drive means. The actuator 18 is associated with the half- part 12, 13 of the sealing unit 10, 10' and enables the lever 19 to be moved from the rest position to the working position and vice versa.
The movement of the rod 17 then acts on the microswitch 16, which is connected to a control unit 22 (illustrated as a block since it is of known type) for controlling the apparatus 1, and which sends to the unit 22 a signal S indicating that the film 9, 9' has been applied to the products 3 correctly when the rod 17 reaches a predetermined lowered position (see Figure 3).
In another arrangement for checking that film 9, 9' has been applied correctly, the rod 17 might be connected to an element 21 for detecting the tension of the film 9, 9'. This detection element 21 would record the deviation of the rod 17 from its rest position, that is to say, from the minimum electrical signal corresponding to this position, to the aforementioned working position in which the rod 17 is raised and produces a signal S1 whose value is proportional to the deviation from the rest position, that is to say, proportional to the inclination of the rod 17.
In other terms, the detection element 21 would be connected to, and would act in conjunction with, the microswitch 16 and would act on the rod 17 in such a way as to produce the signal S1 as a function of the inclination of the rod 17 towards the products 3 when pulled by the film 9, 9'.
In a first embodiment provided by way of example, this detection element consists of a loading cell 21 connected to the rod 17 and acting in conjunction with the microswitch 16: the loading cell 21 permits inclination of the rod 17 towards the products (see Figure 8 again) if the pulling force applied to the rod is greater than a predetermined opposing force applied by the cell 21 itself.
In a second embodiment provided by way of example, the detection element consists of a Hall effect sensor 21, again connected to the rod 17 and acting in conjunction with the microswitch 16.
In a third embodiment provided by way of example, the detection element consists of a proximity sensor 21, again connected to the rod 17 and acting in conjunction with the microswitch 16.
In Figure 3, the detection means 21 and the microswitch 16 are illustrated as blocks since they are of known type.
Below is a description of how the apparatus 1 structured as described above operates, starting from an initial configuration in which the products 3 have moved past the frame 4, unwinding the band or bands of film 9, 9', as illustrated in Figure 5. Described and illustrated is only one of the sealing and cutting units 10 or 10' since the other unit, if fitted, works in exactly the same way.
As shown Figures 5 and 6, the two half parts 12 and 13 of the sealing and cutting unit 10 start moving towards each other (see arrow F10), intercepting the film 9 which is already partly unwound. The unit 11 is initially in the idle position, that is to say, with the sensor-rod 17 in the lowered position (as illustrated in Figure 3). When the two sealing half- parts 12 and 13 are nearly in contact with each other, the rod 17 is "set", that is, raised vertically by the actuator 18 rotating the lever 19 (see Figures 4 and 6).
Next, the half- parts 12 and 13 come into contact with each other, thus sealing and cutting the portion of film 9 wound around the products 3 so as to separate it from the rest of the film 9 (see Figure 7).
The instant it is cut, the film band wound around the products 3 tends to move into contact with the products 3 themselves, followed by the rod 17 which thus moves away at an angle from the half-part 12 it is connected to (see Figure 8 and arrow F17). If a detection unit 21 as described above is fitted, the latter sends a signal S1 to the control unit 22 whose value is a function of the position adopted by the rod 17 and which is compared to the preset minimum initial signal.
At this point, the two half- parts 12 and 13 start moving away from each other towards the idle position, ready for another cycle (see arrow F10R). This causes the rod 17 to pivot downwards, so that it can be disengaged from the film 9, until it is in a substantially horizontal position, thereby activating the microswitch 16, that is to say, closing the circuit of the microswitch 16 itself, and sending a signal S to confirm that the band of film 9 wound around the products has been correctly applied (see Figure 9 and arrow F18).
If the signal or signals S and S1 sent to the unit 22 fall within defined parameters, it means that the band of film 9 has been correctly wound around the products 3 and the apparatus 1 proceeds to the next cycle. If the signals are outside the defined parameters, the apparatus is stopped so that appropriate corrective action can be taken.
The preset aims of the invention are thus achieved by fitting a simple, low-cost and compact unit directly on the sealing and cutting unit of the apparatus.
This arrangement, besides bringing advantages in terms of structure, cost and dimensions, also permits a rapid and immediate inspection of the film band applied, even with reference to two or more parameters, since the inspection is performed during the normal banding cycle without slowing down the process.
The invention described has evident industrial applications and may be subject to modifications and variations without thereby departing from the scope of the inventive concept. Moreover, all the details of the invention may be substituted by technically equivalent elements.

Claims

An apparatus for banding individual, grouped or palletised products, the apparatus (1) being of the type comprising:

a conveyor (2) for transporting the products (3) in a direction of feed (D);

a frame (4) mounted over the conveyor (2) and equipped with at least two rolls (5, 6) of film mounted on the frame uprights (7, 8) in such a way as to form a band of film (9) positioned transversely relative to the uprights (7, 8) and intercepted by the front of the products (3) as they move forward in such a way as to unwind the film (9) from the two rolls (5, 6);

at least one unit (10) for sealing and cutting the film (9), supported by the frame (4) and mobile between an idle position and a working position, where the unit (10) moves in such a way as to define a film wrapping cycle comprising the steps of intercepting the film, sealing it and cutting a portion of the film (9) wrapped around the products (3);

at least one unit (11) at least for inspecting the film (9) and acting on the film (9) itself, the apparatus being characterised in that the unit (11) for inspecting the film (9) is associated with the sealing and cutting unit (10), in that the unit (11) is designed to come into operation after the step of sealing the film (9) has been completed.
The apparatus according to claim 1, characterised in that the unit (11) for inspecting the film (9) is associated with the sealing and cutting unit (10), the unit (11) coming into operation simultaneously with the completion of the cycle of wrapping the film (9) around the products (3).
The apparatus according to claim 1 or 2, characterised in that the unit (11) for inspecting the film (9) comes into operation when the sealing and cutting unit (10) moves from the working position to the idle position.
The apparatus according to claim 1 or 2, characterised in that the unit (11) for inspecting the film (9) comes into operation when the film (9) is released by the sealing and cutting unit (10).
The apparatus according to claim 1, where there are four rolls (5, 6, 5', 6') of film (9, 9'), operating in pairs at two different heights, and two separate units (10, 10') for sealing and cutting the respective film (9, 9'), characterised in that it comprises two units (11, 11') for inspecting the film bands (9, 9') and associated, respectively, with the two sealing and cutting units (10, 10').
The apparatus according to claim 1 or 5, where each unit (10, 10') for sealing and cutting the film (9, 9') is divided into two half-parts (12, 13) each associated with a respective drive beam (14, 15) for moving it from the idle position to the working position and vice versa, characterised in that the respective unit (11, 11') for inspecting the film (9, 9') is associated with one of the half-parts (12, 13) constituting each unit (10, 10') for sealing and cutting the film (9, 9').
The apparatus according to any of the foregoing claims, characterised in that each unit (11, 11') for inspecting the film (9, 9') comprises a microswitch (16) controlled by a sensor (17) that touches the respective film (9, 9') driven by suitable means (18) on the half-part (12, 13) so that it moves at least between a first idle position in which the contact sensor (17) is lowered and a working position in which the sensor (17), when the half-parts (12, 13) are moved towards each other, is raised between the products (3) and the respective film band (9, 9') being wrapped around them.
The apparatus according to claim 7, characterised in that the sensor is in the form of a rod (17) and is linked to a lever (19) forming part of the drive means (18) and able to rotate freely about at least two axes (Z, X) perpendicular to each other and defining a plane parallel to the feed direction (D) of the products (3) in such a way that it is initially angled towards the products (3) to an initial position between the sealed film (9, 9') and the products (3) and is then pulled away from the film (9, 9') when the respective half-part (12, 13) moves from the working position to the idle position.
The apparatus according to claim 8, characterised in that the rod (17) is linked to the lever (19) by a spring (20) which permits the free rotation through at least one arc about the two axes (Z, X) which are perpendicular to each other.
The apparatus according to claim 7 or 8, characterised in that the sensor (17) is linked to the lever (19) which is in turn pivoted to one of the two half-parts (12, 13) of the respective sealing unit (10, 10') and driven by the above mentioned lever (19) drive means (18) from a rest position, in which the lever (19) is parallel to the half-part (12, 13) with the sensor (17) in the lowered position, to a working position, in which the lever (19) is rotated through a predetermined angle (α) and the sensor (17) is in a raised position, that is to say, vertical.
The apparatus according to claims 7 and 8, characterised in that the microswitch (16) is connected to a unit (22) for controlling the apparatus (1), and sends to the unit (22) a signal (S) indicating that the film (9, 9') has been applied to the products (3) correctly when the rod (17) reaches a predetermined lowered position.
The apparatus according to claims 7 and 8, characterised in that the rod (17) has connected to it an element (21) for detecting the tension of the film (9, 9') wound around the products (3), the detection element (21) being designed to record the deviation of the rod (17) from its rest position, that is to say, from the minimum electrical signal corresponding to this position, to the working position in which the rod (17) is raised and produces a signal whose value is proportional to the deviation from the rest position.
The apparatus according to claim 12, characterised in that the detection element (21) is connected to, and acts in conjunction with the microswitch (16), and acts on the rod (17) in such a way that the signal produced is a function of the inclination of the rod (17) towards the products (3) when pulled by the film (9, 9').
The apparatus according to claim 12, characterised in that the means for detecting film tension consist of a loading cell (21) connected to the rod (17) and acting in conjunction with the microswitch (16) and being designed to permit inclination of the rod (17) if the pulling force applied to the rod is greater than a predetermined opposing force applied by the cell (21) itself.
The apparatus according to claim 12, characterised in that the means for detecting film tension consist of a Hall effect sensor (21) connected to the rod (17) and acting in conjunction with the microswitch (16).
The apparatus according to claim 12, characterised in that the means for detecting film tension consist of a proximity sensor (21) connected to the rod (17) and acting in conjunction with the microswitch (16).
The apparatus according to claim 10, characterised in that the lever (19) is linked at one end of it to a pneumatic actuator (18) associated with the half-part (12, 13) of the sealing unit (10, 10') and enabling the lever (19) to be moved from the rest position to the working position and vice versa.