Device and method for producing hermetic wrapping

Abstract

The device (10) for producing hermetic wrappings (100) is configured to receive a structured assembly (AS) and a wrapping sheet (101), to fold the wrapping sheet (101) around said structured assembly (AS) so as to form a tubular arrangement (120) of the wrapping sheet (101), and to move the tubular arrangement (120) through at least one longitudinal welding station (W1, W2) and at least one transverse welding station (W3, W4, W5), so as to weld one longitudinal fin (110) and two transverse fins (111, 112) of the wrapping (100).

Description

[0001] DEVICE AND METHOD FOR PRODUCING HERMETIC WRAPPING

[0002] FIELD OF THE INVENTION

[0003] The present invention concerns a device and a method for producing a hermetic wrapping. In particular, the device and method pertain to the sector of packets of smoking articles, being suitable - for example - to produce a “fin seal” hermetic wrapping with welded lateral fins.

[0004] BACKGROUND OF THE INVENTION

[0005] Smoking articles are traditionally packaged in rigid, or semi-rigid, packets, inside which said smoking articles are wrapped in an internal wrapping, generally made of foil.

[0006] Normally, there is a stiffening element in cooperation with the internal wrapping.

[0007] This type of wrapping is a solution that represents a compromise between production costs and the need to keep the aromatic characteristics of the tobacco present in the smoking articles unchanged.

[0008] In order to better preserve the quality of the smoking articles, there is an increasingly felt need to produce an internal wrapping that is hermetically sealed, that is, obtained with a sheet of material that does not let air pass, suitably sealed around the group of smoking articles contained therein. This hermetically sealed internal wrapping prevents the smoking articles from losing their aroma due to prolonged contact with air before they are to be consumed by users.

[0009] The present invention is linked to technical solutions and operating methods that have been the subject of patent protection. This patent protection covers solutions that, structurally and functionally, are not able to define a result suitable for the intended purpose, and in the required terms.

[0010] In particular, international patent applications WO-A-2016 / 166141, W0-A1- 2018 / 154611 and WO-A1-2019 / 123497 describe machines and methods capable of producing a hermetic wrapping around a group of smoking articles.

[0011] To try to reduce environmental pollution, many countries have the objective of limiting, if not even eliminating, where possible, the use of non-recyclable materials, such as the foil used to produce said internal wrapping for example, therefore there is currently a great need to return to using packaging materials consisting of products of natural origin.

[0012] To achieve this result, packets have been designed in which the wrapping sealed around the smoking articles has a longitudinal fin at one of the larger lateral walls, which is formed by two opposite flaps of the wrapping which are placed in reciprocal contact, and two transverse fins at the ends of the wrapping.

[0013] A particularly critical step of the method concerns the formation of the longitudinal fin while the smoking articles are wrapped with the wrapping. It often occurs that, during this step, the opposite flaps of the wrapping which then form the fin are not in the right position when the wrapping is closed around the smoking articles. For example, it can happen that the two flaps do not perfectly overlap, resulting in an irregular longitudinal fin which can result in a closure of the wrapping that is not perfectly hermetic.

[0014] This occurs even more often when the wrapping has a high stiffness, caused by the natural origin material used.

[0015] There is therefore the need to perfect a device and method for producing internal wrappings that can overcome at least one of the disadvantages of the state of the art, while solving the technical problem of making an ecological wrapping that is free of plastic or non-recyclable materials able to be produced in an automated maimer, with speeds such as to allow for high hourly productivity, for example of the order of several tens of thousands of packets.

[0016] In particular, one purpose of the present invention is to provide an automated welding and folding device, and to perfect a corresponding method, for producing an internal wrapping hermetically sealed around smoking articles, which is capable of producing a wrapping with a straight and regular longitudinal fin, regardless of the wrapping material.

[0017] Another purpose of the present invention is to provide an automated welding and folding device, and to perfect a corresponding method, for producing an internal wrapping hermetically sealed around smoking articles, which is capable of producing a completely ecological and recyclable wrapping, simply and economically.

[0018] Another purpose of the present invention is to provide an automated packaging machine, and to perfect a corresponding method, which allow to achieve good quality wrappings, thanks to processes carried out with high reliability. The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

[0019] SUMMARY OF THE INVENTION

[0020] The present invention is set forth and characterized in the independent claims. The dependent claims describe other features / aspects of the present invention or variants to the main inventive idea.

[0021] In accordance with the above purposes and to resolve the technical problem disclosed above in a new and original way, also achieving considerable advantages compared to the state of the prior art, a device according to the present invention for producing a hermetic wrapping is configured to receive, at a transfer station, a structured assembly and a wrapping sheet, to fold the wrapping sheet around the structured assembly so as to form a tubular pre-wrapping, and to move, along a processing path, the pre-wrapping through at least one longitudinal welding station and at least one transverse welding station, which are located along the processing path, so as to weld one longitudinal fin and two transverse fins.

[0022] In the present description, by the term “pre-wrapping” it is meant the assembly formed by the wrapping sheet and by the structured assembly, wherein the first is wrapped around the second to form a tubular wrapping open at opposite ends, without yet being closed and welded. In other words, the pre-wrapping corresponds to a tubular arrangement of the wrapping sheet around the structured assembly.

[0023] In accordance with one aspect of the present invention, the device comprises at least one abutment member configured to abut the opposite flaps of the wrapping sheet while it is folded around the structured assembly, so as to guarantee they overlap correctly. The at least one abutment member is advantageously positioned at a station for forming the longitudinal fin, in which the wrapping sheet is folded to form the longitudinal fin.

[0024] Doing so achieves at least the advantage of having the opposite flaps correctly positioned and overlapping, regardless of the relative rigidity of the material of the wrapping sheet. The at least one abutment member acts as a guide for positioning, and holding in position, the opposite flaps while the wrapping is folded, so as to correctly and stably form the longitudinal fin.

[0025] In accordance with another aspect of the present invention, the at least one abutment member is mobile between an active position, in which it is close to the wrapping sheet so as to abut its opposite flaps, and an inactive position, in which it is at a distance from the wrapping sheet and cannot come into contact therewith. Advantageously, in the active position the at least one abutment member also comes into contact with the structured assembly, so as to act as an abutment for it and keep it in position.

[0026] In accordance with another aspect of the present invention, the at least one abutment member is positioned at the transfer station, at which the structured assembly and the wrapping are inserted into the device. Advantageously, the insertion of the structured assembly and the wrapping in the device automatically determines the partial folding of the wrapping around the structured assembly.

[0027] In accordance with another aspect of the present invention, the abutment member comprises a pair of plates placed edgeways with respect to the structured assembly, that is, with the lateral edge facing the structured assembly. In this way, the main surfaces of the plates act as a rest for the opposite flaps of the wrapping and help to form the longitudinal fin correctly.

[0028] In accordance with another aspect of the present invention, the body of the device is configured as a wheel rotatable about a rotation axis, the processing path being an arc of a circle between the transfer station and an exit station.

[0029] In accordance with another aspect of the present invention, the device comprises a plurality of conveyor members configured as seatings sized and arranged to each receive one of the tubular arrangements of the wrapping sheet.

[0030] In accordance with another aspect of the present invention, each of the conveyor members comprises an assembly of walls rigidly constrained to the device, and two mobile walls acting from opposite sides with respect to the seating in which the tubular arrangement of the wrapping sheet is accommodated. Preferably, the mobile walls are each supported by a support arm hinged to the device. Advantageously, the two mobile walls alternately assume a closed position, in which they cooperate with the assembly of walls to delimit the respective seating in which the tubular arrangement of the wrapping sheet is accommodated, and an open position, in which they are moved away from the assembly of walls to allow the access of the structured assembly and the wrapping sheet inside the respective conveyor member. In accordance with another aspect of the present invention, the two mobile walls are sized and placed in such a way that, in the closed position, they define a slit between them configured so that the wrapping’s longitudinal fin, which is formed by the nearing of the two opposite flaps of the wrapping sheet folded against the structured assembly, passes through it. The longitudinal fin is configured to protrude outside the conveyor member. Favorably, the at least one abutment member has a thickness smaller, or slightly smaller, than the width of the slit so that it can be inserted therein, in particular together with the wrapping sheet and without damaging the latter. In particular, it can be provided that only an end portion of the abutment member is inserted into the aforementioned slit. In this case, it is sufficient for only this end portion to have a thickness smaller than the width of the slit. The remainder of the abutment member can even have a thickness greater than the width of the slit.

[0031] In accordance with another aspect of the present invention, the device comprises a folding unit for folding the opposite ends of the tubular arrangement of the wrapping sheet, and at least one longitudinal welding unit and at least one transverse welding unit, configured to weld one longitudinal fin and two transverse fins, respectively, arranged at the opposite ends of the wrapping.

[0032] According to another aspect of the present invention, a method is provided for producing a hermetic wrapping comprising a wrapping sheet wrapped around a structured assembly, which comprises an organized group of smoking articles and a stiffening element.

[0033] The method comprises the steps of inserting the structured assembly and a wrapping sheet in a device as disclosed above, folding the wrapping sheet so as to partly wrap it around the structured assembly, moving the at least one abutment member into an active position close to the structured assembly and to the wrapping sheet, folding the wrapping sheet around the structured assembly, taking two opposite flaps of the wrapping sheet into reciprocal contact and into contact with the abutment member, so that their correct overlap is guaranteed, in order to create a longitudinal fin at a lateral surface of the wrapping.

[0034] In accordance with one aspect of the invention, when the at least one abutment member is in the active position, it is in contact with the structured assembly. In this way, the at least one abutment member can act as a support for the structured assembly and keep it stable while the wrapping sheet is folded, and the longitudinal fin is created.

[0035] In accordance with another aspect of the present invention, the insertion of the structured assembly and the wrapping sheet into the device automatically determines a first folding of the wrapping sheet into a U-shape around the structured assembly. Advantageously, the step of folding the wrapping sheet around the structured assembly, by taking two opposite flaps of the wrapping sheet into reciprocal contact and in contact with the abutment member, is carried out immediately after the insertion. In particular, the device is not driven between the insertion and the additional folding step, so as to carry out both operations in the transfer station, and consequently shorten the method’s timings.

[0036] DESCRIPTION OF THE DRAWINGS

[0037] These and other aspects, features and advantages of the present invention will become apparent from the following description of an embodiment, given as a non- restrictive example with reference to the attached drawings wherein:

[0038] - fig. 1 is a three-dimensional view of a device for producing hermetic wrappings, according to the present invention;

[0039] - fig. 2 is a front view of the device of fig. 1;

[0040] - figs. 3A, 4A and 5A are front views of a detail of the device of fig. 1, in three successive operating steps;

[0041] - figs. 3B, 4B and 5B are three-dimensional views of the detail of figs. 3A-5A, in the same three successive operating steps;

[0042] - figs. 6-8 are three-dimensional views of the same detail as figs. 3B-5B, in three other successive operating steps;

[0043] - figs. 9-11 are three-dimensional views of three other details of the device of fig. 1;

[0044] - fig. 12 is an exploded and schematic three-dimensional view of a hermetic wrapping obtainable using the machine and the method according to the present invention;

[0045] - fig. 13 is a schematic three-dimensional view of a hermetic wrapping produced using the machine and the method according to the present invention.

[0046] We must clarify that the phraseology and terminology used in the present description, as well as the figures in the attached drawings also in relation as to how described, have the sole function of better illustrating and explaining the present invention, their purpose being to provide a non-limiting example of the invention itself, since the scope of protection is defined by the claims.

[0047] To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and features of one embodiment can be conveniently combined or incorporated into other embodiments without further clarifications.

[0048] DESCRIPTION OF AN EMBODIMENT OF THE PRESENT INVENTION

[0049] We will now refer in detail to the possible embodiments of the invention, of which one or more examples are shown in the attached drawings, by way of a nonlimiting illustration. The phraseology and terminology used here is also for the purposes of providing non-limiting examples.

[0050] With reference to fig. 1, a device 10 according to the present invention is configured to produce hermetic wrappings, in particular hermetically sealed internal wrappings, referred to as a whole with reference number 100.

[0051] In order to better understand the device 10 we will initially describe, with reference to figs. 12 and 13, a wrapping 100 obtainable with a device 10 according to the present invention, and subsequently, with reference to figs. 3 A- 11, the various operating stations of the device 10.

[0052] The wrapping 100, which does not fall within the scope of protection of the present invention, is made starting from a wrapping sheet 101, configured to be wrapped around an organized group of smoking articles 200.

[0053] By way of a non-limiting example, the wrapping 100 can be of any known type whatsoever, for example such as those described in patent applications W0-A1- 2009 / 148037 and WO-A1-2023 / 217907.

[0054] Preferably, but not only, the wrapping sheet 101 is made of a cellulose-based material, such as, for example, paper, cardboard, or similar materials.

[0055] The wrapping 100 also comprises an opening element 102 configured to facilitate the user at the time of the first opening, when the wrapping 100 that hermetically wraps the smoking articles has to be removed. In the examples described here, the opening element 102 is configured as a ribbon, or a strip, preferably made of natural and recyclable materials, for example cellulose-based materials, such as paper, cardboard, or suchlike. The wrapping 100 also comprises a stiffening element 103, configured to increase the mechanical resistance to impacts of the wrapping 100, which is thus reinforced, so as to protect the integrity of the smoking articles.

[0056] The stiffening element 103, typically made of cardboard, comprises a central panel 104, with a greater extension, and two lateral panels 105, configured to be folded in such a way as to be placed perpendicular with respect to the central panel 104 along respective folding lines 106. The stiffening element 103 comprises a window 107, configured as a recessed portion made at an edge of the central panel 104, so that the presence of the stiffening element 103 does not hinder the user when picking up the smoking articles 200.

[0057] Once the wrapping 100 has been folded and welded, in the maimer that will be explained in more detail below, the wrapping 100 substantially takes the form of a rectangular-based parallelepiped.

[0058] The wrapping 100 therefore comprises two larger lateral walls 108, opposing each other, and two smaller lateral walls 109, opposing each other. The arrangement of the lateral walls is alternated, in such a way that the two smaller lateral walls 109 are contiguous to each larger lateral wall 108 on opposite sides, and the two larger lateral walls 108 are contiguous to each of the smaller lateral walls 109 on opposite sides.

[0059] The wrapping 100 comprises a longitudinal fin 110 which extends parallel to a longitudinal axis X of the wrapping 100, that is, parallel to the direction in which the smoking articles 200 lie.

[0060] In the example given here, the position of the longitudinal fin 110 is preferably about halfway along one of the two larger lateral walls 108, in proximity to an axis of longitudinal symmetry of the larger lateral wall.

[0061] The wrapping 100 also comprises two transverse fins 111, 112, placed at two opposite ends of the wrapping itself.

[0062] The two transverse fins 111, 112 close the wrapping 100 at the lower and upper parts, respectively defining upper and lower closing walls, and are connected both to the larger lateral walls 108 and also to the smaller lateral walls 109.

[0063] It is understood that the device 10 and the method according to the present invention can be configured to also make wrappings 100 which differ both from the one described above with reference to figs. 12 and 13, and also from those described in the aforementioned international patent applications. For example, the position and conformation of some components of the wrapping 100, such as the opening element 102 or the longitudinal fin 110 for example, may differ with respect to these wrappings. In this case, the person of skill will be able to perform the necessary adaptations to the machine 10 and method according to the present invention in order to make the wrapping based on the project specifications.

[0064] The device 10 according to the invention is configured to receive a structured assembly AS, previously made by associating an organized group of smoking articles 200 with a stiffening element 103, together with a wrapping sheet 101, in order to create a tubular arrangement 120 of the wrapping sheet 101, having open ends, wherein the wrapping sheet 101 is wrapped around the structured assembly AS, and also to create the folds and welds on the tubular arrangement 120 that are necessary for closing and sealing the hermetic wrapping 100.

[0065] More specifically, the device 10, which is a folding and welding device, is configured to form and weld the longitudinal fin 110 and perform the necessary folding operations of the opposite ends of the tubular arrangement 120 of the wrapping sheet 101 in order to first form, and subsequently weld, the transverse fins 111, 112.

[0066] In the example described here, the device 10 is configured as a closing wheel 11, rotatable about a rotation axis R. The closing wheel 11 receives, in sequence, a structured assembly AS together with a wrapping sheet 101 at a transfer station T, the association between structured assembly AS and wrapping sheet 101 leading to the formation of the tubular arrangement 120 of the wrapping sheet 101.

[0067] The closing wheel 11 comprises a plurality of conveyor members 20, referred to in the technical field of reference as “forming pockets”. In the example shown, twelve conveyor members 20 are provided, homogeneously distributed along a perimeter edge of the closing wheel 11, angularly distanced from each other by 30°.

[0068] Each conveyor member 20 comprises an assembly of walls 21, 22 which are rigidly constrained to the closing wheel 11. By the expression “rigidly constrained” we mean that these walls are taken into rotation with the wheel about the rotation axis R, but are also “fixed”, since they cannot move with respect to the wheel.

[0069] Specifically, each conveyor member 20 comprises a rear wall 21 and two lateral walls 22, opposing each other with reference to the rear wall 21.

[0070] The closing wheel 11 also comprises a pair of mobile walls 23 associated with each of the second conveyor members 20. Each mobile wall 23 is supported by a respective support arm 24, pivoted to the closing wheel 11 at a respective fulcrum point F.

[0071] The pair of mobile walls 23 can alternatively assume an open position A, in which they allow the transfer of the structured assembly AS, and of the corresponding wrapping sheet 101, to the closing wheel 11, and a closed position C, in which in cooperation with the walls 21, 22 they contribute to delimiting the seating inside which the tubular arrangement 120 is received. When the mobile walls 23 are arranged in the closed position C, a slit 25 is defined between them, configured so that the longitudinal fin 110 passes through it.

[0072] The structured assembly AS and the corresponding wrapping sheet 101 are inserted into the closing wheel 11 by means of a transfer pusher ST, which is not part of the device 10 according to the invention. The transfer pusher ST is placed upstream of the closing wheel 11 at the transfer station T and configured to move the structured assembly AS and the corresponding wrapping sheet 101 directly inside a conveyor member 20.

[0073] The closing wheel 11 comprises a receiving counter-pusher 26 that contacts the wrapping sheet 101 and moves with a movement that is coordinated with respect to the transfer pusher ST, in order to accompany the structured assembly AS and the wrapping sheet 101 inside the conveyor member 20.

[0074] The receiving counter-pusher 26 is normally placed in a backward position behind the conveyor member 20 which, on each occasion, is positioned in the transfer station T. In particular, the receiving counter-pusher 26 is placed behind the rear wall 21. The latter comprises a passage aperture 27, sized so as to allow the counter-pusher to move according to the intended trajectory, as will be described in greater detail below, with reference to the operating sequence shown in figs. 3B-5B and 6-8.

[0075] The device 10 also comprises a pair of abutment members 30 which are configured to abut opposite flaps of the wrapping sheet 101, in particular two opposite flaps that then form the longitudinal fin 110. The abutment members 30 can assume at least a position in contact or flush with a larger side of the structured assembly, for example embodied by the central panel 104 of the stiffening element 103, and longitudinal with respect to the same structured assembly AS, so that when the wrapping sheet 101 is being folded, the opposite end flaps thereof come into contact with and abut against the abutment members 30. In substance, the abutment members 30 can assume at least part of the position of the longitudinal fin 110 to be formed.

[0076] The abutment members 30 are positioned substantially parallel to the rotation axis R of the closing wheel 11, and in symmetrical positions with respect to the median plane of the wheel. The abutment members 30, configured as plates 31 with a substantially rectangular shape, are placed at the transfer station T because, in the example shown, it is in this station that the longitudinal fin 110 of the wrapping 100 is formed.

[0077] The plates 31 are mobile, moving reciprocally close to and away from each other, between an active position and an inactive position in which they are respectively moved close to and away from the structured assembly AS and the wrapping sheet 101, which have just been transferred into the conveyor member 20. It can be inferred that in the active position the plates 31 are positioned flush with the structured assembly AS so that, when the wrapping sheet 101 is folded around it (as will be explained in detail below), its opposite flaps can come into contact with the plates 31 and thus be suitably folded in order to come into reciprocal contact, and thus form the longitudinal fin 110.

[0078] The plates 31 are oriented edgeways with respect to the conveyor member 20, that is, radial or substantially radial with respect to the closing wheel 11. Their larger surfaces, rectangular in shape, thus face the opposite flaps of the wrapping sheet 101 when forming the longitudinal fin 110, and offer an abutment and a greater support to these flaps.

[0079] As stated previously, when the mobile walls 23 are arranged in the closed position C, a slit 25 is defined between them for the passage of the longitudinal fin 110. It is particularly advantageous to provide that the plates 31 have a thickness smaller than the width of the slit 25, in particular slightly smaller, so that they can be placed in such slit 25, between the mobile walls 23 in the closed position C. As can be seen in figs. 7 and 8, only an end portion 32 of the plates 31 is inserted in the slit 25. It is therefore sufficient that only such end portion 32 has a smaller thickness than the width of the slit 25.

[0080] The closing wheel 11 comprises a first welding unit 40 (fig. 9) configured to weld the longitudinal fin 110. The first welding unit 40 can be placed in two successive welding stations Wl, W2, which are placed at two successive positions assumed by the conveyor members 20. By way of example, the first welding unit 40 can comprise two pairs 41 A, 4 IB of welding bars 42, each pair being placed in a respective welding station Wl, W2.

[0081] The welding bars 42 can be heated welding bars of a type known in the art, placed parallel to the longitudinal fin 110 to be welded, that is, in a plane that is radial, or substantially radial, with respect to the closing wheel 11. The welding bars 42 are mounted on a jaw mechanism 43 that alternately takes them into contact with, or away from, the longitudinal fin 110, from opposite sides with respect to the latter.

[0082] The closing wheel 11 further comprises a folding unit 50 (fig. 10), which comprises a plurality of folding members 51, organized into specialized pairs, each pair suitable to perform a specific folding of the wrapping sheet 101 around the structured assembly AS, so as to close the tubular arrangement 120. The folding unit 50, by way of a non-limiting example, can be substantially similar to that described in patent application WO-A 1-2018 / 154611, to which, however, a specific folder is added, configured to fold the longitudinal fin 110. For example, this specific folder can comprise a mobile wall 52 located outside the structured assembly AS with respect to the closing wheel 11 and containing an abutment edge 52A parallel to the longitudinal fin 110 (fig. 10). The mobile wall 52 moves transversely with respect to the longitudinal axis X of the structured assembly AS so as to abut the longitudinal fin 110 with the abutment edge 52A, thus knocking it down against the corresponding larger lateral wall 108 of the wrapping 100.

[0083] The closing wheel 11 further comprises a second welding unit 60 (fig. 11) provided with welding members 61, for welding the transverse fins 111, 112. The second welding unit 60 can be placed in three successive welding stations W3, W4, W5, which are placed at three successive positions assumed by the conveyor members 20 and which also follow the previous two welding stations Wl, W2 at which the first welding unit 40 is placed.

[0084] The second welding unit 60, in the example shown here, is therefore provided with three units 61 A, 6 IB, 61C each containing two pairs of welding bars 62 oriented parallel to the transverse fins 111, 112 (therefore substantially tangent to the closing wheel 11). In each unit 61 A, 6 IB, 61C, the two pairs of welding bars 62 (only one of which is visible in the drawings) are positioned symmetrically with respect to the median plane of the closing wheel 11.

[0085] The first welding unit 40, the folding unit 50 and the second welding unit 60 are arranged in succession so that a tubular arrangement 120 of the wrapping sheet 101 contained in a conveyor member 20, during the rotation of the latter about the rotation axis R, meets the aforementioned operating units in sequence, which perform the respective processes on the pre-wrapper 120, folding and welding the wrapping sheet 101 as described above.

[0086] In the embodiment shown here, it is provided that the folding unit 50 and the second welding unit 60 partly overlap in a same operating station, in this case the welding station W3 in which, immediately after having made some folds on the wrapping sheet 101, it is provided to perform one or more welds by means of suitable welding members 61 in order to fix the flaps just folded by the folding members 51 in position.

[0087] Downstream of the last welding station W5 there is provided an exit station SO at which the hermetically closed wrappings 100 exit from the closing wheel 11 and are transferred to additional conveyor and / or processing units. In particular, the exit station SO is here at the bottom vertical point of the wheel, so that the wrappings 100 can exit from the wheel simply by falling, without using specific members. For this purpose, it is clear that the mobile walls 23 have to be taken into their open position A. Alternatively, a special pusher can also be provided, configured to push the wrappings 100 parallel to the rotation axis R of the closing wheel 11, toward an additional conveyor located in front of the same wheel.

[0088] The closing wheel 11 can comprise a discard station SD, located downstream of the exit station SO and at which the wrappings 100 that are not in compliance are discarded, for example those for which the wrapping sheet 101 has not been folded correctly, or one of the fins has not been properly welded.

[0089] The operation of the device 10 described heretofore comprises the following steps.

[0090] Initially, a step of inserting a structured assembly AS and a wrapping sheet 101 into the closing wheel 11, at the transfer station T, is performed.

[0091] Here, the mobile walls 23 of the conveyor member 20 which is placed in this same transfer station T are taken into the open position A, and the receiving counter-pusher 26 is moved forward until it contacts the wrapping sheet 101 (fig. 3 A, 3B), moving as indicated by the arrow Fl.

[0092] Subsequently, the transfer pusher ST pushes the structured assembly AS toward the same conveyor member 20, as indicated by the arrow F2 (fig. 4 A, 4B). During this movement, the structured assembly AS meets the wrapping sheet 101, which is fed from above. At this point, the structured assembly AS and the wrapping sheet 101 are engaged between the transfer pusher ST and the receiving counter-pusher 26. The receiving counter-pusher 26 also reverses the direction of movement and moves together with the transfer pusher ST in the direction of the arrow F2.

[0093] Both the transfer pusher ST and the receiving counter-pusher 26 move together, in a coordinated maimer, to take the structured assembly AS together with the corresponding wrapping sheet 101 inside the conveyor member 20 which is placed in the transfer station T. The entry of the wrapping sheet 101 into the conveyor member 20 determines its passage from the extended configuration in which it finds itself, to a configuration in which it is folded in a U-shape against the walls 21, 22, as shown in fig. 5A, 5B.

[0094] At this point, the abutment members 30, which were in their inactive position, are driven and taken into their active position, while the transfer pusher ST is still in contact with the structured assembly AS (fig. 6). Once they have reached their active position, the abutment members 30 are also in contact with the structured assembly AS, and the retraction of the transfer pusher ST is commanded (fig. 7).

[0095] Subsequently, the mobile walls 23 move from the open position A to the closed position C, folding the opposite flaps of the wrapping sheet 101 that project outside the conveyor member 20 against the structured assembly AS and against the abutment members 30 (fig. 8), and thus forming the tubular arrangement 120 open at the opposite ends.

[0096] Doing so guides the folding of the ends of the opposite flaps, which are engaged in the slit 25 between the mobile walls 23 and the abutment members 30, so that these flaps can surely be in reciprocal contact when the abutment members 30 are removed. The longitudinal fin 110 which protrudes through the slit 25 outside the conveyor member 20 is thus formed.

[0097] The operation continues by commanding the abutment members 30 to take them back into the inactive position (fig. 8).

[0098] Continuing the rotation, the closing wheel 11 takes the tubular arrangement 120 into the welding and folding stations, in which, in order:

[0099] - the first welding unit 40 welds the longitudinal fin 110, at the welding stations Wl, W2 (fig. 9),

[0100] - the folding unit 50 makes all the folds of the wrapping sheet 101 to close its opposite ends, at the next welding station W3 (fig. 10),

[0101] - the second welding unit 60 welds the transverse fins 111, 112 at the welding stations W3, W4, W5 (fig.11).

[0102] Subsequently, the hermetically sealed wrapping 100 is taken to the exit station SO where the mobile walls 23 are taken into their open position A, thus allowing the wrapping 100 to fall freely (fig. 2).

[0103] If a non-conformity of the wrapping 100 has been detected, at the exit station SO the mobile walls 23 are kept in the closed position C and, by making the closing wheel 11 rotate further by 30°, the wrapping 100 to be discarded is located at the next discard station SD, where the mobile walls 23 can be opened in order to free the wrapping 100.

[0104] It is clear that modifications and / or additions of parts may be made to the device 10 and method as described heretofore, without departing from the field and scope of the present invention, as defined by the claims.

[0105] It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art will be able to achieve other equivalent forms of device and method for producing hermetic wrappings, having the features as set forth in the claims and hence all coming within the field of protection defined thereby.

[0106] In the following claims, the sole purpose of the references in brackets is to facilitate their reading and they must not be considered as restrictive factors with regard to the field of protection defined by the claims.

Claims

CLAIMS1. Device (10) for producing hermetic wrappings ( 100), configured to receive, at a transfer station (T), a structured assembly (AS) of smoking articles (200) and a wrapping sheet (101), to fold said wrapping sheet (101) around said structured assembly (AS) so as to form a tubular arrangement (120) of the wrapping sheet (101), and to move, along a processing path, said tubular arrangement (120) through at least one longitudinal welding station (Wl, W2) and at least one transverse welding station (W3, W4, W5), which are located along said processing path, so as to weld one longitudinal fin (110) and two transverse fins (111, 112), characterized in that it comprises at least one abutment member (30) configured to abut opposite flaps of said wrapping sheet (101) while it is folded around said structured assembly (AS), so as to guarantee their correct overlap and the correct formation of said longitudinal fin (110).

2. Device (10) as in claim 1, characterized in that said at least one abutment member (30) is mobile between an active position, in which it is close to said wrapping sheet (101) and said structured assembly (AS) so as to be able to abut said opposite flaps, and an inactive position, in which it is at a distance from said wrapping sheet (101) and from said structured assembly (AS), and cannot come into contact therewith.

3. Device (10) as in claim 1 or 2, characterized in that said at least one abutment member (30) is placed in said transfer station (T).

4. Device (10) as in any claim hereinbefore, characterized in that said at least one abutment member (30) comprises a pair of plates placed edgeways with respect to said structured assembly (AS) in such a way that its lateral edge faces the structured assembly.

5. Device (10) as in any claim hereinbefore, characterized in that it comprises a plurality of conveyor members (20) configured as seatings sized and arranged to each receive one of said tubular arrangements (120) of the wrapping sheet (101).

6. Device (10) as in claim 5, characterized in that each of said conveyor members (20) comprises an assembly of walls (21, 22) rigidly constrained to said device (10) and two mobile walls (23) acting from opposite sides with respect to said seating in which said tubular arrangement (120) of the wrapping sheet (101)is accommodated and which alternately assume a closed position (C), in which they cooperate with said assembly of walls (21, 22) to delimit the respective seating in which said tubular arrangement (120) of the wrapping sheet (101) is accommodated, and an open position (A), in which they are moved away from said assembly of walls (21, 22) to allow the access of said structured assembly (AS) and said wrapping sheet (101) inside the respective conveyor member (120).

7. Device (10) as in claim 6, characterized in that said mobile walls (23) are sized and placed in such a way that, in said closed position (C), they define a slit (25) between them configured so that said longitudinal fin (110) of said wrapping (100) passes through it, and that said at least one abutment member (30) has, at least at one end portion (32) thereof, a thickness smaller than the width of said slit (25), so that it can be inserted into said slit (25).

8. Method for producing hermetic wrappings (100), each comprising a wrapping sheet (101) wrapped around a structured assembly (AS) of smoking articles (200), comprising the steps of inserting said structured assembly (AS) and one said wrapping sheet (101) in a device (10) as in any claim hereinbefore, moving said at least one abutment member (30) into an active position, moved close to said structured assembly (AS) and to said wrapping sheet (101), folding said wrapping sheet (101) so as to partly wrap it around said structured assembly (AS), taking two opposite flaps of said wrapping sheet (101) into reciprocal contact and into contact with said at least one abutment member (30).

9. Method as in claim 8, characterized in that said at least one abutment member (30), in said active position, comes into contact with said structured assembly (AS).

10. Method as in claim 8 or 9, characterized in that the step of inserting said structured assembly (AS) and said wrapping sheet (101) into said device (10) automatically determines the folding of said wrapping sheet (101) into a U-shape around said structured assembly (AS), and in that said step of folding said wrapping sheet (101), taking said flaps into reciprocal contact, is carried out immediately after said inserting step, by taking mobile walls (23) of a conveyor member (20) comprised in said device (10) from an open position (A) to a closed position (C).

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