WO2011015244A1

WO2011015244A1 - Packaging assembly

Info

Publication number: WO2011015244A1
Application number: PCT/EP2009/060207
Authority: WO
Inventors: Francesco Maria Bernardi
Original assignee: Dp S.R.L.
Priority date: 2009-08-06
Filing date: 2009-08-06
Publication date: 2011-02-10
Also published as: EP2462026A1

Abstract

A packaging assembly, which comprises a driving unit for at least one member (2) for gripping a product (3) to be packaged, along a predefined closed path (4), and means for moving, along a first direction (A) that substantially interferes with a useful segment (4a) of the closed path (4), a heat-sealing member (6) for flaps of film wrapped around the product (3); the movement means define a second direction (B) of motion, for the heat-sealing member (6), that is substantially parallel to the useful segment (4a); the rule of motion along the active stroke of the heat-sealing member (6) in the second direction (B) is substantially synchronous with the movement of the product (3) along at least one portion of the useful segment (4a).

Description

PACKAGING ASSEMBLY

Technical field

The present invention relates to a packaging assembly.

Background Art

In the field of packaging machines, for various kinds of articles, and particularly for rolls of paper of the tissue type (for example absorbent paper or toilet paper), machines are widespread which are capable of packing a predefined number of rolls in order to define the packaging unit that is usually sold to the end consumer.

According to a known constructive solution, these machines have first of all devices for feeding the rolls, which are then taken by handling means, for example conveyor belts or platforms. Along such means there are apparatuses capable of diverting the flow of part of the rolls in order to arrange them as a whole along multiple rows or layers.

Once the rolls are arranged in the desired configuration, they are in practice ready for performing the wrapping cycle, for which purpose the rolls are delivered to a traction device, for example by means of a lifting unit (typically consisting of a pusher that can move along its own axis).

The above cited traction devices commonly consist of a plurality of grip means, which can move along a substantially annular path, along which they are arranged with constant spacing.

After the delivery of the roll to the device by the lifting unit, during traction the roll is wrapped with the film (folded by appropriately provided elements) and the film is heat-sealed in a downward region, for closure of the pack.

According to known constructive solutions, the lower heat-sealing of the film occurs by means of a heat-sealing bar which, by performing a translational motion, moves into contact with the film, seals it and then moves away again to allow the advancement of the product.

However, this constructive solution is not free from drawbacks. The type of heat-sealing used sets severe constraints to the possible final configurations of the machine.

It should in fact be noted that the position where the heat-sealing occurs is determined unambiguously by the stop positions of the traction and by the size of the products.

Due to the way in which the above described bar works, it is not possible to perform heat-sealing during the movement of the product and therefore this operation occurs during a static step of the stepwise operation of the machine, at one of the points where the grip means stop along the annular path.

In greater detail, heat-sealing occurs exactly two steps away from the point where the pack is delivered by the lifting unit, in order to allow, in the intermediate region, the arrangement of the film moving and folding members.

If it is necessary to change the longitudinal position of the heat- sealing unit with respect to the traction, for example due to a variation in the dimensions of the rolls and of the pack, it is therefore necessary to work during a machine stop in order to make the heat-sealing unit perform the appropriate movements to bring it to the new position; moreover, this modification necessarily has to be accompanied by a reconfiguration of the entire traction device.

The construction constraints that arise from the adoption of such a type of heat-sealing member are not limited only to the position in which the heat-sealing bar works but also concern the time available to perform the heat-sealing itself.

The time available is in fact limited upward by the total stop time of the grip means during each cycle of the machine. This total time in turn is linked to various operating parameters of the other processing steps, and as such cannot be varied or adjusted, except at the price of fundamental structural modifications of the units that compose the automatic machine. Disclosure of the Invention

The aim of the present invention is to solve the problems noted above, by providing a packaging assembly in which the heat-sealing member can work along any point of the path followed by the product to be packaged.

Within this aim, an object of the invention is to provide a packaging assembly that allows optimization of the heat-sealing time, regardless of the times and parameters of the operation of the other steps of the wrapping cycle.

Another object of the invention is to provide a packaging assembly that ensures high reliability in operation.

Another object of the invention is to provide a packaging assembly that can be obtained easily starting from common commercially available elements and materials.

Another object of the invention is to provide a packaging assembly that has low costs and is safe in application.

This aim and these objects and others, that will become better apparent hereinafter, are achieved by a packaging assembly, which comprises a driving unit for at least one member for gripping a product to be packaged, along a predefined closed path, and means for moving, along a first direction that interferes substantially with a useful segment of said closed path, a heat-sealing member for flaps of film wrapped around the product, characterized in that said movement means define a second direction of motion, for said heat-sealing member, that is substantially parallel to said useful segment, the rule of motion along the active stroke of said heat-sealing member in said second direction being substantially synchronous with the movement of the product along at least one portion of said useful segment.

Brief description of the drawings

Further characteristics and advantages of the invention will become better apparent from the description of a preferred but not exclusive embodiment of the packaging assembly according to the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figures 1 to 7 are schematic lateral elevation views of the operation of the packaging assembly according to the invention.

Ways of carrying out the Invention

With reference to the figures, a packaging assembly according to the invention, generally designated by the reference numeral 1 , comprises a driving unit that is capable of moving at least one grip member 2 for gripping a product 3 to be packaged along a predefined closed path 4.

It should be noted immediately that the packaging assembly 1 according to the invention can comprise any number of grip members 2 that can move along the closed path 4. The choice of the number depends, during the design of the assembly 1 , on the search for the best balance among different and mutually opposite requirements, such as for example optimization of the accelerations of the various components, containment of the costs inevitably linked to the presence of a large number of grip members 2 and the possibility to increase the efficiency of the assembly 1 by processing simultaneously a larger number of products 3.

According to one possible constructive solution, shown in the accompanying figures, the closed path 4 has a shape that is composed of two half-circles interposed between two parallel straight portions, and on one of the straight portions, the lower one, there is a useful segment 4a for the traction of the products 3 (the remainder of the closed path 4 is instead used for the return stroke).

The products 3 are for example rolls of paper of the tissue type, i.e., toilet paper, absorbent paper or the like; the desired final configuration of the rolls, which are arranged on multiple rows and layers, is obtained in the preceding steps of the wrapping cycle and defines the product 3 to be packaged.

This spatial configuration must of course be maintained by the grip members 2 during traction, while the subsequent processing steps are performed.

The products 3 are entrusted to the grip member 2, for example, by a pusher that can perform an upward and downward translational motion at a delivery station 5a.

As mentioned, the packaging of the products 3 is then performed along the useful segment 4a by wrapping in a sheet of plastic film and by folding the flaps of film that protrude at the end of the products 3.

This function is performed by an apparatus for unwinding and folding the film, which is arranged proximate to the useful segment 4a and to the delivery station 5a of the products 3.

The folded flaps are subsequently heat-sealed by virtue of a welding member 6, which is moved, along a first direction A that substantially interferes with the useful segment 4a (for example because it is perpendicular to it) by appropriate movement means.

Finally, at an expulsion station 5b the packs thus provided are delivered to any subsequent processing steps or are simply made available for palletizing and marketing.

The useful segment 4a, which is substantially straight, is therefore formed between the delivery station 5a and the expulsion station 5b.

According to the invention, the movement means define a second direction of motion B, for the heat-sealing member 6, which is substantially parallel to the useful portion 4a. The rule of motion along the active stroke of the heat-sealing member 6 along such second direction of motion B is substantially synchronous with the movement of the product 3 along at least one portion of the useful segment 4a.

In this manner, the heat-sealing member 6 can "follow" the grip member 2 during its motion along the useful segment 4a or at least along a portion thereof. Heat-sealing can thus occur during the movement of the products 3, differently from what occurred in the packaging assemblies of the background art, in which, since the heat-sealing member 6 moved only along the first direction A, it was possible to operate only during a stop of the grip members 2.

Preferably, the heat-sealing member 6 comprises a heat-sealing bar 7, which is substantially comb-shaped and is suitable to perform spot welding, which guarantees a better quality of said heat-sealing than continuous heat- sealing, for the particular type of elements to be heat-sealed (two flaps of film and a soft material such as paper of the tissue type in contrast).

In particular, the combination of the movements along the first direction A and the second direction B defines an annular trajectory for the heat-sealing bar 7. Part of this trajectory constitutes the active stroke cited above, for heat-sealing of the folded film flaps.

It should be noted that with respect to what has been observed in the background art, in the assembly 1 according to the invention it is possible to move the heat-sealing member 6 and the heat-sealing bar 7 closer to the delivery station 5a. In greater detail, since it is not necessary to perform heat-sealing at a stop station of the grip members 2, the initial part of the active stroke of the heat-sealing bar 7 can be implemented proximate to the delivery station 5 a.

Accordingly, it is evident that the unwinding and folding apparatus and the heat-sealing member 6 are both arranged below and proximate to the useful segment 4a of the closed path 4; in particular, the unwinding apparatus can be located along the path traced by the heat-sealing bar 7.

The risk of interference between the two components is avoided during design by resorting to appropriate constructive choices. For example, according to one possible constructive solution, it is possible to provide recesses or undulated profiles for the heat-sealing member 6 in order to allow the passage of the movable elements of the unwinding and folding apparatus, while said apparatus has a plurality of slots which are elongated along the advancement direction of the products 3 and in which the teeth of the comb-shaped heat-sealing bar 7 can be inserted and can slide. In this manner, the risk of interference is avoided and the heat-sealing bar 7 can thus move into contact with the film wound onto the products 3, in order to proceed with the heat-sealing of the flaps.

It should be noted that the result that is obtained also ensures the additional advantage of reducing significantly the overall space required by the assembly 1.

The heat-sealing bar 7 can slide with respect to the second direction B in appropriately provided guides formed in tracks 8 that are arranged parallel to the useful segment 4a, below and externally with respect to the closed path 4.

In order to ensure the movement of the heat-sealing bar 7 along the above-cited tracks 8, and therefore with respect to the second direction B, the movement means comprise a linear motor, for example of the type of a linear induction motor controlled by respective control and management devices.

As an alternative, to perform the same function the movement means can comprise a brushless motor, with the interposition of transmission means, to convert the rotary motion produced by said motor into the desired reciprocating rectilinear motion.

According to one solution of particular practical interest which however does not limit the application of the invention, in order to allow the heat-sealing bar 7 to perform the desired annular trajectory, the assembly 1 according to the invention comprises an actuation system capable of conferring the heat-sealing bar 7 a component of motion along the first direction A.

More particularly, this actuation system might comprise an eccentric element or a cam, rigidly supported by a shaft which in turn is functionally associated with the movement means.

It should also be rioted that the heat-sealing member 6 can have constructive solutions which are different from the one described above, but which nevertheless are within the scope of protection defined by the present description: for example, the heat-sealing member 6 might be constituted by a plurality of heat-sealing heads, which can move along a closed circuit that is arranged proximate to the delivery station 5a and to the useful segment 4a.

The operation of the packaging assembly according to the invention is as follows.

Once the product 3 to be packaged has been received, the grip members 2 move it along the useful segment 4a of the closed path 4.

The apparatus for unwinding and folding of the film works along said closed path 4 and winds the rolls directly downstream of the delivery station 5a.

Once this operation has ended, heat-sealing can be performed at any point of the remaining part of the useful segment 4a. The heat-sealing member 6 in fact can move parallel to the grip member 2, and therefore the area of action can be chosen during design independently of the constraints imposed by the constructive parameters related to the other processing steps.

In particular, the heat-sealing cycle can be implemented during the movement of the grip member 2: in this manner, all the time needed by the grip member 2 to travel along the useful path 4a is available, and it is thus possible to increase said heat-sealing time (with beneficial effects on the quality of the heat-seal) while not causing an increase in overall processing time.

Finally, it should be noted that the heat-sealing member 6 described above can be coupled effectively with assemblies that provide for a stepwise advancement of the grip members 2; in this case, the movement along the second direction B can be used simply to adjust said assembly 1 according to the dimensions of the rolls.

If instead the movement of the grip members 2 is continuous, the described heat-sealing member 6 allows optimization of the accelerations and stresses on the components of the machine, since it is no longer necessary for the various components to perform continuous stops and restarts.

In practice it has been found that the packaging assembly according to the invention fully achieves the intended aim, since by guaranteeing the possibility of the heat-sealing element to move synchronously in a second direction that is parallel to the useful portion of the closed path traced by the grip members, it is possible to heat-seal the folded flaps of film along any point of said closed path.

The invention thus conceived is susceptible to numerous modifications and variations, all of which are within the scope of the appended claims; all the details may furthermore be replaced by other technically equivalent elements.

In the exemplary embodiments shown, individual characteristics, given in relation to specific examples, may actually be interchanged with other different characteristics that exist in other exemplary embodiments.

Moreover, it should be noted that anything found to be already known during the patenting process is understood not to be claimed and to be the subject of a disclaimer.

In practice, the materials used, as well as the dimensions, may be any according to the requirements and the state of the art.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. A packaging assembly, comprising a driving unit for at least one member (2) for gripping a product (3) to be packaged, along a predefined closed path (4), and means for moving, along a first direction (A) that substantially interferes with a useful segment (4a) of said closed path (4), a heat-sealing member (6) for flaps of film wrapped around the product (3), characterized in that said movement means define a second direction (B) of motion, for said heat-sealing member (6), that is substantially parallel to said useful segment (4a), the rule of motion along the active stroke of said heat-sealing member (6) in said second direction (B) being substantially synchronous with the movement of the product (3) along at least one portion of said useful segment (4a).

2. The packaging assembly according to claim 1, characterized in that it comprises a station (5a) for delivery of the products (3) to be packaged to said at least one grip member (2) and a station (5b) for expelling the packaged products (3), a substantially rectilinear portion of said closed path (4), delimited by said delivery station (5a) and by said expulsion station (5b) constituting said useful segment (4a).

3. The packaging assembly according to claim I₅ characterized in that said heat-sealing member (6) comprises a heat-sealing bar (7) that can slide with respect to said second direction (B) along guides formed in tracks (8) that are arranged parallel to said useful segment (4a).

4. The packaging assembly according to one or more of the preceding claims, characterized in that the movement of said heat-sealing bar (7) along said first direction (A) and said second direction (B) has a substantially annular trajectory, which comprises said active stroke, an initial portion of said active stroke being proximate to said delivery station (5a).

5. The packaging assembly according to one or more of the preceding claims, characterized in that it comprises a film unwinding and folding apparatus for packaging the products (3), said apparatus being arranged π

proximate to said useful segment (4a) and to said station (5a) for the delivery of the products (3).

6. The packaging assembly according to one or more of the preceding claims, characterized in that at least one element of said unwinding and folding apparatus, arranged proximate to said useful portion (4a) and along the trajectory of said heat-sealing bar (7), has a plurality of slots, which are suitable to accommodate temporarily the teeth of said heat-sealing bar (7), which is substantially comb-shaped, said teeth being able to slide within said slots in order to come into contact with the film wrapped around the products (3).

7. The packaging assembly according to claim 3. characterized in that said means comprise a linear motor, which is suitable to move said heat- sealing bar (7) along said second direction (B).

8. The packaging assembly according to claim 3 and as an alternative to claim 6, characterized in that said means comprise a brushless motor which is functionally associated with transmission means for moving said heat-sealing bar (7) along said second direction (B).

9. The packaging assembly according to one or more of the preceding claims, characterized in that it comprises an actuation system, functionally associated with said heat-sealing bar (7), that is suitable to provide it with a component of motion along said first direction (A).

10. The packaging assembly according to claim 8, characterized in that said actuation system comprises an eccentric element that is supported rigidly by a shaft that is functionally associated with said movement means.

1 1. The packaging assembly according to claim 8 and as an alternative to claim 9, characterized in that said actuation system comprises a cam that is supported rigidly by a shaft that is functionally associated with said movement means.