Wrapping unit and method for producing two sealed wraps by simultaneously folding two wrap sheets around two corresponding groups of smoking articles

Description

Cross-Reference to Related Applications

[0001] This Patent Application claims priority from Italian Patent Application No. 102022000005690 filed on March 23, 2022.Technical Field

[0002] The present invention relates to wrapping unit and to a wrapping method to produce two sealed wraps, together, by simultaneously folding two wrapping sheets around two corresponding groups of smoking articles.

[0003] The present invention finds advantageous application to the production of a rigid pack of cigarettes with a "twin" type hinged lid and containing two twin sealed wraps next to one another, to which the following disclosure will make explicit reference without thereby losing generality.Prior Art

[0004] Rigid packs of cigarettes with hinged lids are currently the most widespread packs of cigarettes on the market as they are simple to produce, are easy and practical to use, and offer good protection to the cigarettes contained within the same.

[0005] A rigid pack of cigarettes with a hinged lid comprises a wrap formed by a group of cigarettes wrapped in a wrapping sheet and a rigid outer casing which houses the wrap on the inside thereof. The outer casing is formed by a cup-shaped container, which houses the wrap and has an open upper end, and a lid, which is also cup-shaped and is hinged to the container to rotate, with respect to the container, between an open position and a closed position of the open end.

[0006] In a traditional pack of cigarettes, the group of cigarettes is wrapped in a rectangular wrapping sheet of glue-free metallized paper. To preserve the integrity of the tobacco of the cigarettes, it has been proposed to produce a sealed (waterproof) wrap formed by a wrapping sheet of waterproof and heat-sealable material having an extraction opening for the cigarettes, which is closed by a reusable closing label.

[0007] A pack of cigarettes commercially known as "twin" has been known for several years, it comprises a rigid outer container which houses two groups of identical cigarettes (namely, "twins", hence the commercial name of this pack of cigarettes), which are arranged next to one another and are wrapped in corresponding wrapping sheets.

[0008] Patent US4258528A and patent EP3362365B1 describe a packing machine which produces a rigid pack of cigarettes with a "twin" type hinged lid and containing two twin wraps next to one another. Further patent WO 2021 / 084477 A1 describes a packaging machine for forming this kind of packs, this machine is provided with two folding devices coupled to a wrapping conveyor.Description of the Invention

[0009] The object of the present invention is to provide a wrapping unit and method to produce two sealed wraps, together, by simultaneously folding two wrapping sheets around two corresponding groups of smoking articles, which packing machine and wrapping method are simple to implement, allow to operate at a high production speed (measured as packs of cigarettes produced per unit of time), and allow format change operations to be carried out quickly.

[0010] According to the present invention, a wrapping unit and method are provided to produce two sealed wraps, together, by simultaneously folding two wrapping sheets around two corresponding groups of smoking articles, as claimed in the appended claims.

[0011] The claims describe embodiments of the present invention forming an integral part of the present description.Brief Description of the Drawings

[0012] The present invention will now be described with reference to the attached drawings, which illustrate a non-limiting embodiment thereof, wherein: Figure 1 is a front perspective view and in a closed configuration of a rigid pack of cigarettes; Figure 2 is a rear perspective view of the pack of cigarettes of Figure 1 in a closed configuration; Figure 3 is a front perspective view of the pack of cigarettes of Figure 1 in an open configuration; Figure 4 is a front perspective view of a sealed wrap contained in the pack of cigarettes of Figure 1; Figure 5 is a perspective view of a group of cigarettes coupled to a reinforcing element and contained in the sealed wrap of Figure 4; Figure 6 is a plan view devoid of folds of the reinforcing element of Figure 5; Figure 7 is a plan view of a wrapping sheet used to obtain the sealed wrap of Figure 4; Figure 8 is a plan view of a blank used to obtain an outer container provided with a hinged lid of the pack of cigarettes of Figure 1; Figures 9-16 illustrate some folding steps of the wrapping sheet of Figure 7 around the group of cigarettes of Figure 5 in order to obtain the sealed wrap of Figure 4; Figure 17 is a front view and with parts removed for clarity of a packing machine which produces the pack of cigarettes of Figure 1 and is made according to the present invention; Figure 18 is a perspective view showing the paths followed by the components of the pack of cigarettes of Figure 1 in the packing machine of Figure 17; Figure 19 is a perspective view and on an enlarged scale of a detail of Figure 18; Figure 20 is a schematic plan view of an initial part of the packing machine of Figure 17; Figure 21 is a schematic front view of three wrapping drums of the packing machine of Figure 17; Figure 22 is a schematic plan view of a wrapping drum and a linear wrapping conveyor of the packing machine of Figure 17; Figure 23 is a front view and with parts removed for clarity of the three wrapping drums of Figure 21; Figure 24 is a perspective view and with parts removed for clarity of two wrapping drums of Figure 21 and of the linear wrapping conveyor of Figure 22; Figures 25 and 26 are two different schematic views of the linear wrapping conveyor of Figure 22; Figures 27, 28 and 29 are schematic views of the linear wrapping conveyor of Figure 22 with sealing heads in three different positions taken at different operating moments; Figure 30 is a perspective and schematic view of a pocket of a wrapping drum of Figure 21; and Figure 31 is a schematic view of two folding devices of the packing machine of Figure 17. Preferred Embodiments of the Invention

[0013] In Figures 1, 2 and 3, number 1 denotes as a whole a rigid "twin" pack of cigarettes. The pack 1 of cigarettes comprises an outer container 2 made of rigid and cup-shaped cardboard or paperboard and a pair of wraps 3 (one of which is better illustrated in Figure 4) housed next to one another inside the container 2.

[0014] The outer container 2 has an open upper end and is provided with a lid 4, which is cup-shaped and is hinged to the outer container 2 along a hinge 5 (illustrated in Figure 2) to rotate, with respect to the outer container 2, between an open position (illustrated in Figure 3) and a closed position (illustrated in Figures 1 and 2) of the open upper end. The outer container 2 has a substantially rectangular parallelepiped shape oriented according to a substantially vertical development direction, is cup-shaped, and has an open upper end, a lower wall 6 opposite the open upper end, a front wall 7 and a rear wall 8 (in which the hinge 5 is formed) parallel and opposite to one another, and two side walls 9 parallel and opposite to one another.

[0015] The lid 4 has a substantially rectangular parallelepiped shape, is cup-shaped, and has an open lower end (facing the open upper end of the outer container 2 when the lid 4 is in the closed position), an upper wall 10 (which is parallel and opposite the lower wall 6 of the outer container 2 when the lid 4 is in the closed position), a front wall 11 (which is parallel and aligned with the front wall 7 of the outer container 2 when the lid 4 is in the closed position), a rear wall 12 (which is parallel and aligned with the rear wall 8 of the outer container 2 when the lid 4 is in the closed position and is hinged to the rear wall 8 of the outer container 2 along the hinge 5), and two side walls 13 parallel and opposite to one another (which are parallel and aligned, in particular coplanar and adjacent, to the side walls 9 of the outer container 2 when the lid 4 is in the closed position).

[0016] Each sealed wrap 3 (illustrated in Figure 4) encloses a group 14 of cigarettes (partially illustrated in Figure 5) having a parallelepiped shape; each cigarette is provided with a filter 15 and therefore the group 14 of cigarettes has an upper wall made up of the circular ends (tips) of the filters 15 and a lower wall, opposite the upper wall, made up of the circular ends (tips) of the tobacco rods.

[0017] As illustrated in Figure 4, the sealed wrap 3 has an opening 16 at the top and in front for extracting the cigarettes, which is delimited by a pre-weakened tearable line, is closed by a reusable closing label 17 and affects a portion of a front wall of the sealed wrap 3 and a portion of an upper wall of the sealed wrap 3. According to a preferred embodiment, the closing label 17 is fixed to the cigarette sealed wrap 3 by means of a re-stick glue that does not dry, which is applied to the lower surface of the closing label 17 and is arranged all around the extraction opening 16 to allow the closing label 17 to be repeatedly partially separated from the sealed wrap 3 and then re-fixed to the sealed wrap 3.

[0018] According to a different embodiment not illustrated, the sealed wrap 3 is devoid of the extraction opening 16 and of the respective closing label 17 and has a removable upper portion, which is separated from the rest of the sealed wrap 3 by a pre-weakened tearable line to be removed by tearing at the first opening of the sealed wrap; in this embodiment, the sealed wrap 3 is preferably provided with a tearable opening strip to facilitate the breaking of the sealed wrap 3 along the pre-weakened line.

[0019] The sealed wrap 3 is obtained by folding a wrapping sheet 18 (illustrated in Figure 7), which has a rectangular shape, comprises at least one layer of air-tight and heat-sealable plastic material, and is folded directly around the group 14 of cigarettes so as to be in direct contact with the cigarettes. Once the wrapping sheet 18 has been folded around the group 14 of cigarettes to form the sealed wrap 3, the shape of the sealed wrap 3 is stabilized by heat-sealing the overlapping portions of the wrapping sheet 18.

[0020] Before folding the wrapping sheet 18 around the group 14 of cigarettes, the wrapping sheet 18 is pre-cut to define the extraction opening 16; subsequently, the closing label 17 with glue at the bottom, that is, provided on its lower surface with the re-stick glue which, inside the extraction opening 16, causes the permanent gluing of an inner portion of the wrapping sheet 18 to the closing label 17 and outside the extraction opening 16 causes a separable gluing of the wrapping sheet 18 to the closing label 17, is applied to the wrapping sheet 18.

[0021] As illustrated in Figures 4 and 5, the sealed wrap 4 could comprise a reinforcing element 19, which is made of cardboard or rigid paperboard, is "U"-shaped and is arranged inside the sealed wrap 3 in contact with the group 14 of cigarettes. The function of the reinforcing element 19 is to give greater rigidity and greater shape stability to the sealed wrap 3 so as to prevent the sealed wrap 3 from collapsing upon itself after having removed part of the cigarettes contained in the sealed wrap 3 making the extraction of the remaining cigarettes complicated and in particular making the opening and subsequent re-closing of the closing label 17 extremely complicated. A further function of the reinforcing member 19 is to provide mechanical protection to the cigarettes during folding of the wrapping sheet 18, mechanical and thermal protection to the cigarettes during heat sealing of the overlapping portions of the wrapping sheet 18, and mechanical protection to the cigarettes while handling the sealed wrap 3.

[0022] As better illustrated in Figure 6 , the reinforcing element 19 comprises a front wall 20 arranged in contact with the cylindrical side walls of the cigarettes of the group 14 of cigarettes, two side walls 21 arranged on opposite sides of the front wall 20 in contact with the cylindrical tips of the cigarettes of the group 14 of cigarettes, a lower wall 22 arranged in contact with the tips of the cigarettes of the group 14 of cigarettes (namely, arranged in contact with the lower wall of the group 14 of cigarettes), and a (small) rear wall 23 arranged in contact with the cylindrical side walls of the cigarettes of the group 14 of cigarettes from the opposite side of the front wall 20. Preferably, the front wall 20 has an upper flaring 24 which is arranged at the cigarette extraction opening 16 so that the front wall 20 does not overlap the cigarette extraction opening 16.

[0023] The formation of the sealed wrap 3 provides for initially forming the group 14 of cigarettes and then folding the reinforcing element 19 around the group 14 of cigarettes (obtaining what is illustrated in Figure 5). Subsequently and as illustrated in Figure 9, the wrapping sheet 18 is folded around the group 14 of cigarettes coupled to the reinforcing element 19. The group 14 of cigarettes has: two larger side walls which are opposite one another and are made up of the cylindrical side walls of the cigarettes, two smaller side walls which are opposite one another and are made up of the cylindrical side walls of the cigarettes, an upper wall made up of ends of the filters 15, and a lower wall formed by the ends (tips) of the tobacco rods.

[0024] Initially, the group 14 of cigarettes is coupled to the outspread wrapping sheet 18 by bringing the upper wall (on the side of the filters 15) of the group 14 of cigarettes into contact with the wrapping sheet 18 (as illustrated in Figure 9); subsequently, the wrapping sheet is folded in a "U"-shape around the group 14 of cigarettes (as illustrated in Figure 10) so that the wrapping sheet 18 folded in a "U"-shape is arranged in the area of the upper wall and of the two larger side walls of the group 14 of cigarettes and having two ends 25 and 26, which are parallel to the larger side walls and protrude from the larger side walls (namely, continue beyond the larger side walls); it is important to observe that the wrapping sheet 18 is fed asymmetrically in front of the group 14 of cigarettes (namely, the wrapping sheet 18 is arranged asymmetrically against the upper wall of the group 14 of cigarettes) to define the two ends 25 and 26, which both protrude from the group 14 of cigarettes and have a different length (namely, the end 25 is longer than the end 26 and the difference in length between the end 25 and the end 26 is equal to the width of the lower wall of the group 14 of cigarettes). As illustrated in Figure 10, the end 25 is parallel to a first larger side wall of the group 14 of cigarettes and protrudes from the first lower wall of the group 14 of cigarettes continuing beyond the larger side wall; similarly, the end 26 is parallel to a second larger side wall of the group 14 of cigarettes and protrudes from the lower wall of the group 14 of cigarettes continuing beyond the second larger side wall.

[0025] As illustrated in Figure 11 , the end 25 is folded by 90° with respect to the first larger side wall of the group 14 of cigarettes and against the bottom wall of the group 14 of cigarettes and, simultaneously, a final part of the end 25 is folded by 90° to give the end 25 an "L" shape and then arrange the final part of the end 25 parallel to and resting on the end 26 (which does not undergo, in this step, any type of folding, that is, it remains parallel to the second larger side wall) giving the wrapping sheet 18 a tubular shape; in other words, at the same time (namely, with the same folding action) the end 25 is folded by 90° in two distinct points: a first fold by 90° around the corner between the first larger side wall and the lower wall and a second fold at the corner between the second larger side wall and the lower wall (near the end 26) so as to give the end 25 an "L" shape and rest the final part of the end 25 against the ends 26.

[0026] When the end 25 is folded into an "L" shape and rests (in its final part) on the end 26, a tubular shape is given to the wrapping sheet 18 having two open side edges (illustrated in Figure 16) in the area of the smaller side walls of the group 14 of cigarettes. At this point, as illustrated in Figure 12, the overlapping portions of the ends 25 and 26 are heat-sealed to one another to stabilize the tubular shape of the wrapping sheet 18 and to form a sealing fin 27. Finally, the overlapping and heat-sealed ends 25 and 26 (namely, the sealing fin 27) are folded by 90° against the lower wall of the group 14 of cigarettes (as illustrated in Figure 13) and with the interposition of part of the wrapping sheet 18. Alternatively, the mutually overlapping and heat-sealed ends 25 and 26 (namely, the sealing fin 27) are folded by 180° against the second larger side wall of the group 14 of cigarettes (as illustrated in Figure 14) and with the interposition of part of wrapping sheet 18.

[0027] According to a further embodiment illustrated in Figure 15, the two ends 25 and 26 have the same length, they are both folded into an "L" shape against the lower wall of the group 14 of cigarettes to form the sealing fin 27, and finally the sealing fin 27 (which is initially in the centre of the bottom wall of the group 14 of cigarettes) is folded by 90° against the bottom wall of the group 14 of cigarettes.

[0028] Subsequently, and as illustrated in Figure 16, the two open side edges of the wrapping sheet 18 (which has a tubular shape around the group 14 of cigarettes) are closed by means of the so-called "soap-bar fold" that for each side edge provides for: folding two smaller wings 28 and 29 against the smaller side wall of the group 14 of cigarettes (in fact, the smaller wing 28 arranged at the top wall of the group 14 of cigarettes is folded previously when the wrapping sheet 18 is first in contact with the group 14 of cigarettes and folds in a "U"-shape around the group 14 of cigarettes), folding a larger wing 30 against the smaller side wall of the group 14 of cigarettes and over the two previously folded smaller wings 28 and 29, and finally folding the other larger wing 31 against the smaller side wall of the group 14 of cigarettes and over the two smaller wings 28 and 29 and the larger wing 30 previously folded. After completing the folding of the wrapping sheet 18 around the group 14 of cigarettes by closing the two side edges by means of respective side folds, these side folds are stabilized by heat sealing, namely, by heat sealing the overlapping parts of the wrapping sheet 18 at the smaller side walls of the group 14 of cigarettes.

[0029] As illustrated in Figure 8, the outer container 2 and the lid 4 are made by folding a blank 32 of the conventional type.

[0030] Number 33 in Figure 17 denotes as a whole a packing machine which is suitable for making the pack 1 of cigarettes described above and works with intermittent motion (namely, a motion that provides for a cyclical alternation of motion steps and stop steps) .

[0031] The packing machine 33 comprises a forming unit A in which the groups 14 of cigarettes are formed in succession, a wrapping unit B in which a respective wrapping sheet 18 is wrapped around each group 14 of cigarettes to form a sealed wrap 3, and a wrapping unit C in which a blank 32 is wrapped around each pair of coupled sealed wraps 3 (namely, arranged next to one another) to form an outer container 2 provided with a lid 4.

[0032] The forming unit A to form groups 14 of cigarettes comprises a hopper 34 provided with three outlet mouths 35 for simultaneously feeding three pairs of groups 14 of cigarettes to three respective pairs of pockets 36 of a forming conveyor 37 that supports a plurality of pairs of pockets 36: each pocket 36 is designed to contain a group 14 of cigarettes and the pockets 36 are grouped in pairs so that a plurality of pairs of pockets 36 next to one another are provided. In other words, from each outlet mouth 35 two groups 14 of cigarettes next to one another are extracted together and inserted together into two corresponding pockets 36 arranged next to one another.

[0033] The forming conveyor 37 comprises an annular shaped conveyor belt, which is wound around two end pulleys (one of which is motorized), supports the pockets 36 and moves in a step-like manner to cyclically move the pockets 36 along a forming path P1 (illustrated in Figure 20). As better illustrated in Figure 20, the forming path P1 develops between an inlet station S1 in which each pair of groups 14 of cigarettes is extracted from an outlet mouth 35 of the hopper 34 and enters a corresponding pair of pockets 36 and a transfer station S2 in which each pair of groups 14 of cigarettes is extracted from the corresponding pair of pockets 36.

[0034] As illustrated in Figure 20, the wrapping unit B comprises a wrapping conveyor 38 which is arranged downstream of the forming conveyor 37 (namely, it receives the pairs of groups 14 of cigarettes next to one another from the forming conveyor 37 in the transfer station S2) and is designed to move the pairs of groups 14 of cigarettes next to one another together with the corresponding wrapping sheets 18 along a wrapping path P2 to (start to) fold each wrapping sheet 18 around the corresponding group 14 of cigarettes. In particular, the wrapping path P2 extends from the transfer station S2 in which the wrapping conveyor 38 receives two groups 14 of cigarettes at a time from a corresponding pair of pockets 36 of the forming conveyor 37, passes through a feeding station S3 in which each pair of groups 14 of cigarettes next to one another is coupled with a corresponding pair of wrapping sheets 18 next to one another, and ends in a transfer station S4 in which the pairs of sealed wraps 3 being formed (namely, each formed by a wrapping sheet 18 only partially folded around a corresponding group 14 of cigarettes) leave the wrapping conveyor 38.

[0035] In particular, along the wrapping path P2 (namely, as it is moved by the wrapping conveyor 38) each wrapping sheet 18 is initially folded in a "U"-shape and subsequently into a tube around a corresponding group 14 of cigarettes and the tubular wrap (having two open side ends) thus formed is stabilized by transverse sealing (as illustrated in Figures 9-15).

[0036] As illustrated in Figure 20, the wrapping unit B comprises a wrapping conveyor 39 which is arranged downstream of the wrapping conveyor 38 (namely, it receives the pairs of groups 14 of cigarettes next to one another and coupled to the wrapping sheets 18 from the wrapping conveyor 38) and is designed to move the pairs of groups 14 of cigarettes next to one another and coupled to the wrapping sheets 18 along a straight wrapping path P3 to (finish of) folding each wrapping sheet 18 around the corresponding group 14 of cigarettes. In particular, the wrapping path P3 extends from a transfer station S5 in which the wrapping conveyor 39 receives two groups 14 of cigarettes coupled to the wrapping sheets 18 at a time and ends in a transfer station S6 (illustrated in the Figure 22) in which the pairs of complete sealed wraps 3 (namely, each formed by a wrapping sheet 18 completely folded around a corresponding group 14 of cigarettes) leave the wrapping conveyor 39.

[0037] In particular, along the wrapping path P3 (namely, while it is moved by the wrapping conveyor 39) each tubular wrap 3 is closed laterally by means of side folds which are subsequently stabilized by means of two longitudinal seals completing (terminating) the forming of the tubular wrap 3 (as illustrated in Figure 16).

[0038] As illustrated in Figure 20, the wrapping unit B comprises a wrapping drum 40 (arranged horizontally) which is interposed between the wrapping conveyor 38 and the wrapping conveyor 39, is mounted so as to rotate around a vertical rotation axis 41 (perpendicular to the wrapping path P3), and supports four pairs of pockets 42 (illustrated in Figures 21 and 22), each designed to contain a group 14 of cigarettes coupled to a wrapping sheet 18 (therefore a pair of pockets 42 next to one another supports a pair of groups 14 of cigarettes next to one another and coupled to the respective wrapping sheets 18). The wrapping drum 40 by rotating around the rotation axis 41 moves each pair of pockets 42 next to one another along a circular wrapping path P4 between the transfer station S4 where the pair of pockets 42 next to one another receives a pair of groups 14 of cigarettes next to one another and coupled to the wrapping sheets 18 by the wrapping conveyor 38 and the transfer station S5 in which the pair of pockets 42 next to one another releases the pair of groups 14 of cigarettes next to one another and coupled to the wrapping sheets 18 to the wrapping conveyor 39.

[0039] As better illustrated in Figure 21, the wrapping conveyor 38 comprises a wrapping drum 43 (vertically arranged) which is arranged immediately downstream of the forming conveyor 37, is mounted so as to rotate around a horizontal rotation axis 44 (parallel to the wrapping path P3 and perpendicular to the rotation axis 41), and supports a plurality of pairs of pockets 45, each designed to contain a group 14 of cigarettes coupled to a wrapping sheet 18 (therefore a pair of pockets 45 axially next to one another supports a pair of groups 14 of cigarettes next to one another and coupled to the respective wrapping sheets 18). The wrapping drum 43 by rotating around the rotation axis 44 moves each pair of pockets 45 next to one another along the circular wrapping path P2 between the transfer station S2 where the pair of pockets 45 next to one another receives a pair of groups 14 of cigarettes next to one another from the forming conveyor 37, through the feeding station S3 in which the pair of pockets 45 next to one another receives a pair of wrapping sheets 18 next to one another which are arranged outside the pair of pockets 45 next to one another, and a transfer station S7 in which the pair of pockets 45 next to one another releases the pair of groups 14 of cigarettes next to one another and coupled to the wrapping sheets 18.

[0040] As better illustrated in Figure 21, the wrapping conveyor 38 comprises a wrapping drum 46 (vertically arranged) which is arranged immediately downstream of the wrapping drum 43 and immediately upstream of the wrapping drum 40, is mounted so as to rotate around a horizontal rotation axis 47 (parallel to the rotation axis 44 and perpendicular to the rotation axis 41), and supports a plurality of pairs of pockets 48, each designed to contain a group 14 of cigarettes coupled to a wrapping sheet 18 (therefore a pair of pockets 48 axially next to one another supports a pair of groups 14 of cigarettes next to one another and coupled to the respective wrapping sheets 18). The wrapping drum 46 by rotating around the rotation axis 47 moves each pair of pockets 48 next to one another along the circular wrapping path P2 between the transfer station S7 in which the pair of pockets 48 next to one another receives a pair of groups 14 of cigarettes next to one another and coupled to the wrapping sheets 18 by the wrapping drum 43 and the transfer station S4 in which the pair of pockets 48 next to one another releases the pair of groups 14 of cigarettes next to one another and coupled to the wrapping sheets 18 to the wrapping drum 40.

[0041] In other words, in the feeding station S3 two wrapping sheets 18 arranged next to one another are arranged on the periphery of the wrapping drum 43 in the area of a respective pair of pockets 45 next to one another and move with the respective pair of pockets 45 next to one another until the transfer station S7; in the transfer station S7 the two groups 14 of cigarettes next to one another, by exiting the pair of pockets 45 next to one another of the wrapping drum 43 and entering the respective pair of pockets 48 next to one another of the wrapping drum 46, pull therewith the two wrapping sheets 18 next to one another, which by entering in the pockets 48, fold in a "U"-shape around the groups 14 of cigarettes next to one another (as well illustrated in Figure 19).

[0042] Along the wrapping path P2, the wrapping conveyor 38 moves the groups 14 of cigarettes with a longitudinal orientation (namely, with the cigarettes parallel to the wrapping path P2 and the cigarette filters 15 arranged at the front or at the back) . Also along the wrapping path P3 the wrapping conveyor 39 moves the groups 14 of cigarettes with a longitudinal orientation (namely, with the cigarettes parallel to the wrapping path P2 and the cigarette filters 15 arranged in front).

[0043] As illustrated in Figures 21, 23 and 24, the packing machine 33 comprises two folding devices 49, each coupled to the wrapping drum 46 and configured to fold a wrapping sheet 18 into a tube around the corresponding group 14 of cigarettes contained in a respective pocket 48. Each wrapping sheet 18 is folded in a "U"-shape around the corresponding group 14 of cigarettes when the group 14 of cigarettes enters (together with the wrapping sheet 18) the respective pocket 48 in the transfer station S7 and as illustrated in Figure 10; moreover, each folding device 49 performs the tubular folding of each wrapping sheet 18 around the corresponding group 14 of cigarettes illustrated in Figures 10 and 11. The wrapping drum 46 moves along the wrapping path P2 a succession of pairs of groups 14 of cigarettes next to one another and coupled to the wrapping sheets 18 (by means of corresponding pairs of pockets 48 next to one another) and therefore the two folding devices 49 are arranged next to one another to perform together and simultaneously the folding of two wrapping sheets 18 around two groups 14 of cigarettes next to one another.

[0044] Furthermore, the packing machine 33 comprises two sealing devices 50, each coupled to the wrapping drum 46 and configured to perform a transverse seal on a wrapping sheet 18 folded into a tube around the corresponding group 14 of cigarettes contained in a respective pocket 48. According to a preferred embodiment, each sealing device 50 comprises three different sealing heads 51 arranged in succession around the wrapping drum 46 (namely, along the wrapping path P2) so that the transverse seal on each wrapping sheet 18 folded into a tube is performed in three distinct and successive steps (a sealing head 51 is also schematically illustrated in Figure 12). The wrapping drum 46 moves along the wrapping path P2 a succession of pairs of groups 14 of cigarettes next to one another and coupled to the wrapping sheets 18 and therefore the two sealing devices 50 are next to one another to perform together and simultaneously the sealing of two wrapping sheets 18 around two groups 14 of cigarettes next to one another.

[0045] As illustrated in Figure 22, the packing machine 33 comprises two folding devices 52, each coupled to the wrapping conveyor 39 and configured to fold a wrapping sheet 18 around the corresponding group 14 of articles, completing the formation of the sealed wrap 3, namely, by closing the two open ends of the wrapping sheet 18 folded into a tube as illustrated in Figure 16. The wrapping conveyor 39 moves along the wrapping path P2 a succession of pairs of groups 14 of cigarettes next to one another and coupled to the wrapping sheets 18 and therefore the two folding devices 52 are next to one another to fold together and simultaneously the two wrapping sheets 18 around two groups 14 of cigarettes next to one another.

[0046] In particular, each folding device 52 comprises two fixed folding screw-like blades 53 and 54 (namely, folding profiles devoid of moving parts) arranged along the wrapping path P3 (namely, along the wrapping conveyor 39). In particular, four fixed folding screw-like blades 53 and 54 are provided as a whole, each folds a side end of a corresponding wrapping sheet 18 folded into a tube: the wrapping conveyor 39 moves a succession of pairs of groups 14 of cigarettes arranged next to one another and coupled to the wrapping sheets 18 folded into a tube along the wrapping path P3, therefore for each group 14 of cigarettes two fixed folding screw-like blades 53 and 54 are required, arranged at the two opposite ends of the group 14 of cigarettes. Consequently, two fixed folding screw-like blades 53 are arranged at the centre of the wrapping conveyor 39 (one fixed folding screw-like blade 53 which operates with the group 14 of cigarettes arranged to the right and the other fixed folding screw-like blade 53 which operates with the group 14 of cigarettes arranged to the left) and two folding screw-like blades 54 fixed to the sides of the wrapping conveyor 39 (one fixed folding screw-like blade 54 which operates with the group 14 of cigarettes arranged to the right and the other fixed folding screw-like blade 54 which operates with group 14 of cigarettes arranged to the left).

[0047] As illustrated in Figure 22, the packing machine 33 comprises two sealing devices 55, each coupled to the wrapping conveyor 39 and configured to perform the longitudinal seal on a wrapping sheet 18 folded around the group 14 of cigarettes, thus completing the formation of the corresponding sealed wrap 3.

[0048] Each sealing device 55 is coupled to the wrapping conveyor 39 and is arranged along the wrapping path P3 downstream of the respective folding device 52 to obtain a seal on two sides of a wrapping sheet 18 folded around a corresponding group 14 of cigarettes. According to a preferred embodiment, each sealing device 55 comprises a plurality of outer sealing heads 56 arranged outside the wrapping conveyor 39 and a plurality of inner sealing heads 57 arranged in the middle of the wrapping conveyor 39 (namely, in the central free area between two groups 14 of cigarettes next to one another). Accordingly, two inner sealing heads 57 are arranged at the centre of the wrapping conveyor 39 (one inner sealing head 57, which operates with the group 14 of cigarettes arranged to the right and the other inner sealing head 57, which operates with the group 14 of cigarettes arranged to the left) and two outer sealing heads 56 on the sides of the wrapping conveyor 39 (one outer sealing head 56, which operates with the group 14 of cigarettes arranged to the right and the other outer sealing head 56, which operates with group 14 of cigarettes arranged to the left) . Each sealing device 55 comprises several sealing heads 56 and 57 arranged in succession along the wrapping conveyor 39 (namely, along the wrapping path P3) so that the longitudinal seal on each wrapping sheet 18 is performed in several distinct and successive steps.

[0049] The wrapping conveyor 39 moves along the wrapping path P3 a succession of pairs of groups 14 of cigarettes arranged next to one another and coupled to the wrapping sheets 18 and therefore the two sealing devices 55 are next to one another to perform together and simultaneously the sealing of two wrapping sheets 18 around two groups 14 of cigarettes next to one another.

[0050] As previously stated, along the wrapping path P2 (and therefore in the area of the wrapping conveyor 38) a feeding station S3 is provided, in which pairs of wrapping sheets 18 next to one another are arranged on the periphery of the wrapping drum 43 in the area of a pair of pockets 45 next to one another (containing two respective groups 14 of cigarettes next to one another) .

[0051] As illustrated in Figure 23, the packing machine 32 comprises a feeding device 58 (only partially illustrated) which cyclically feeds the wrapping sheets 18 into the feeding station S3, namely, it arranges pairs of wrapping sheets 18 next to one another in the feeding station S3 so that each pair of wrapping sheets 18 is arranged on the periphery of the wrapping drum 43 in the area of a pair of pockets 45 next to one another. The feeding device 58 comprises an unwinding station wherein one single band 59 of wrapping material (illustrated in Figure 18) having a double width is unwound from a reel (not illustrated) and is moved (passing alongside the hopper 33) towards a known type of cutting member 60 which is arranged above the feeding station S3 and cyclically performs a transverse cut of the band 59 of wrapping material to separate, from the band 59 of wrapping material, portions of the band 59 of wrapping material which make-up the respective pairs of wrapping sheets 18 next to one another (and still joined together). Furthermore, the feeding device 58 comprises a cutting member 61 of a known type which is arranged above the feeding station S3 downstream of the cutting member 60 and cyclically performs a longitudinal cut of each portion of the band 59 of wrapping material (which has been separated from the head of the band 59 of wrapping material by the cutting member 60) to divide the portion of the band 59 of wrapping material into two wrapping sheets 18 next to one another (and no longer joined together).

[0052] The feeding device 58 could also comprise a processing member (for example an embosser) which is arranged between the unwinding station and the cutting member 60 and performs a processing (for example an embossing) of the band 59 of wrapping material.

[0053] As previously stated, the cutting member 61 is configured to cut the single double-width band 59 of wrapping material in half to obtain from the single band 59 of wrapping material a series of pairs of wrapping sheets 18 arranged in mutual contact (separated from one another by a cutting line but in mutual contact along the longitudinal cutting line, namely, at zero distance from one another). The wrapping conveyor 38 (formed by the two wrapping drums 43 and 46) is configured to move each pair of groups 14 of cigarettes next to one another in which the two groups 14 of cigarettes are arranged at mutual distance so that the groups 14 of cigarettes are centred relative to the corresponding wrapping sheets 18 arranged in mutual contact. Similarly, the wrapping conveyor 39 is also configured to move the groups 14 of cigarettes in which the two groups 14 of cigarettes are arranged at the same mutual distance as the wrapping conveyor 38, namely, they are arranged at a mutual distance so that the groups 14 of cigarettes are centred relative to the corresponding wrapping sheets 18 arranged in mutual contact.

[0054] The fact that after the longitudinal cut performed by the cutting member 61 the two wrapping sheets 18 are not spaced (separate) from one another but remain in mutual contact along the longitudinal cutting line (namely, they remain at zero distance from one another) allows to simplify the treatment of the two wrapping sheets 18 and also allows to make the whole wrapping unit B more compact (smaller).

[0055] In the embodiment illustrated in Figure 23 , the feeding device 58 comprises a suction feeding drum 62 which is mounted so as to rotate around a horizontal rotation axis 63 (parallel to the rotation axis 44) and cooperates with the cutting member 60 and a successive suction feeding drum 64 which is mounted so as to rotate around a horizontal rotation axis 65 (parallel to the rotation axis 44) that is arranged immediately downstream of the feeding drum 62 and cooperates with the cutting member 61. In particular, the feeding drum 64 represents the final component of the feeding device 58 and cyclically arranges a pair of wrapping sheets 18 next to one another on the periphery of the wrapping drum 43 in the area of a pair of pockets 45 next to one another and in the feeding station S3.

[0056] As illustrated in Figure 17, the wrapping unit C of the packing machine 33 comprises a wrapping drum 66 which is arranged downstream of the wrapping conveyor 39, supports a plurality of pockets 67 each designed to contain a pair of sealed wraps 3 arranged next to one another (and in mutual contact), and is mounted so as to rotate (with an intermittent motion, namely in a "step-like" manner) around a horizontal rotation axis 68 perpendicular to the wrapping path P3 to move each pocket 67 along a circular wrapping path parallel to the wrapping path P3. Each pocket 67 of the wrapping drum 66 receives a pair of sealed wraps 3 arranged next to one another (and in mutual contact) in a transfer station S8, receives a blank 32 in a feeding station S9 arranged downstream of the transfer station S8 along the wrapping path, and releases together the pair of sealed wraps 3 arranged next to one another (and in mutual contact) and the blank 32 in the transfer station S10 arranged downstream of the feeding station S9 along the wrapping path.

[0057] In the feeding station S9, each blank 32 is arranged against the outer surface of the wrapping drum 66 in the area of a pocket 67 and is held in this position by means of suction; in the transfer station S10, a pair of sealed wraps 3 arranged next to one another, coming out of the corresponding pocket 67, pulls therewith the previously fed blank 32.

[0058] The packing machine 33 comprises a feeding device 69 which cyclically feeds the blanks 32 in the feeding station S9, namely, arranges each blank 32 in front of a pocket 67.

[0059] The packing machine 33 comprises a wrapping drum 70 which is arranged downstream of the wrapping drum 66, supports a plurality of pockets 71 each designed to contain a pair of sealed wraps 3 and a blank 32, and is mounted so as to rotate (with an intermittent motion, namely in a "step-like" manner) around a horizontal rotation axis 72 parallel to the rotation axis 67 to move each pocket 71 along a circular wrapping path. Each pocket 71 of the wrapping drum 72 receives a pair of sealed wraps 3 and a blank 32 in the transfer station S10, folds the blank 32 downstream of the transfer station S10, and releases an almost complete pack 1 of cigarettes (missing only the folding of a pair of wings which form the outer part of the side walls 9 and 13) in a transfer station S11 arranged downstream of the transfer station S10 along the wrapping path. In the transfer station S11, the folding of each blank 32 is completed (thus completing the formation of the corresponding pack 1 of cigarettes) immediately downstream of the wrapping drum 70. Once the formation of each pack 1 of cigarettes has been completed, the pack 1 of cigarettes is transferred to a drying conveyor (not illustrated) which moves the packs 1 of cigarettes in succession towards an outlet of the packing machine 33.

[0060] As illustrated in Figure 24, the packing machine 33 comprises a transfer drum 73 which is interposed between the wrapping conveyor 39 and the wrapping drum 66, supports a plurality of pockets 74 each designed to contain a pair of sealed wraps 3 next to one another (and arranged at a given distance from one another), and is mounted so as to rotate (with an intermittent motion, namely in a "step-like" manner) around a vertical rotation axis 75 (therefore perpendicular to the rotation axis 68 of the wrapping drum 66 and to the wrapping path P3) to move each pocket 74 along a circular transfer path between the transfer station S6 where the pocket 74 receives a pair of sealed wraps 3 next to one another (and arranged at a given distance from one another) from the wrapping conveyor 39 and a transfer station S12 in which the pocket 74 releases the pair of sealed wraps 3 next to one another. The transfer station S12 is vertically aligned with the transfer station S8 and is arranged below the transfer station S8; a pushing element (lifter) is provided, which is movable vertically from the bottom upwards and is designed to transfer a pair of sealed wraps 3 next to one another from the transfer station S12 to the transfer station S8 (namely, from a pocket 74 of the transfer drum 73 to a pocket 67 of the wrapping drum 66). In the vertical path from the transfer station S12 to the transfer station S8 the two sealed wraps 3 next to one another can be pushed towards each other so as to bring to zero their mutual distance (namely, initially in the transfer station S12 the two sealed wraps 3 next to one another are at a given distance from one another while at the end in the transfer station S8 the two sealed wraps 3 next to one another are in mutual contact).

[0061] According to an alternative embodiment not illustrated, to the wrapping drum 66 collars could also be fed, which become part of the packs 1 of cigarettes.

[0062] From the foregoing, it is clear that the rotation axes 44 and 47 of the wrapping drums 43 and 46 are horizontal, are parallel to the wrapping path P3, and are perpendicular to the rotation axes 68 and 72 of the wrapping drums 66 and 70. Furthermore, from the foregoing, it is clear that the wrapping path P2 of the wrapping conveyor 38 is perpendicular to the forming path P1 of the forming conveyor 37.

[0063] As illustrated in Figures 25 and 26, each sealing device 55 comprises an actuator 76 configured to move, during the regular operation of the packing machine 33, the sealing heads 56 and 57 between a work position (illustrated in Figure 28) in which the sealing heads 56 and 57 have a first mutual distance which causes a compression of the corresponding sealed wraps 3 (each containing a group 14 of cigarettes wrapped in a wrapping sheet 18) and a moving position (illustrated in Figure 27) in which the sealing heads 56 and 57 have a second mutual distance which is greater than the first mutual distance and allows the corresponding sealed wraps 3 (each containing a group 14 of cigarettes wrapped in a wrapping sheet 18) to move along the wrapping path P3 without touching the sealing heads 56 and 57.

[0064] Obviously, the sealing heads 56 and 57 take the work position (illustrated in Figure 28) when the wrapping conveyor 39 is in a stop step (namely, standing still) and so as to allow the sealing heads 56 and 57 to carry out the longitudinal heat-sealing of the overlapping ends of the wrapping sheet 18; the compression exerted by the sealing heads 56 and 57 on the sealed wraps 3 (each containing a group 14 of cigarettes wrapped in a wrapping sheet 18) allows to optimally perform the longitudinal heat-sealing of the overlapping ends of the wrapping sheet 18. On the other hand, the sealing heads 56 and 57 take the moving position (illustrated in Figure 27) when the wrapping conveyor 39 is in a motion step (namely, in movement) to allow the corresponding sealed wraps 3 (each containing a group 14 of cigarettes wrapped in a wrapping sheet 18) to move along the wrapping path P3 together with the wrapping conveyor 39 without sliding against the sealing heads 56 and 57.

[0065] Furthermore, each actuator 76 is configured to move, only when the packing machine 33 is stopped, the sealing heads 56 and 57 to a rest position (illustrated in Figure 29) in which the sealing heads 56 and 57 have a third mutual distance which is (largely) greater than the second mutual distance and allows to prevent the heat emanating from the sealing heads 56 and 57 from overheating the sealed wraps 3 which could remain still along the wrapping path P3 even for several minutes.

[0066] In other words, the wrapping conveyor 39 has a step-wise law of movement alternating motion steps and stop steps; each actuator 76 is configured to hold the sealing heads 56 and 57 in the moving position during the motion steps of the wrapping conveyor 39 and to move the sealing heads 56 and 57 from the moving position to the work position and vice versa during the stop steps of the wrapping conveyor 39. Furthermore, each actuator 76 is configured to move the sealing heads 56 and 57 to the rest position when the wrapping unit B (namely, the entire packing machine 33) is stopped and, hence, the wrapping conveyor 39 is stopped.

[0067] By way of example, the stroke performed by the sealing heads 56 and 57 to move between the moving position and the work position is approximately 1-2 mm, whereas the stroke performed by the sealing heads 56 and 57 to move to the rest position is about 5-10 mm.

[0068] According to the embodiment illustrated in the attached figures, each actuator 76 is configured to move the sealing heads 56 and 57 between the work position and the moving position along a direction D1 horizontal and perpendicular to the wrapping path P3 and is configured to move only the inner sealing heads 57 to and from the rest position along a direction D2 vertical and perpendicular to the direction D1 and to the wrapping path P3. Namely, according to the embodiment illustrated in the attached figures, each actuator 76 is configured to move only the inner sealing heads 57 to and from the rest position along the direction D2 and is configured to move the outer sealing heads 56 to and from the rest position along the direction D1. According to a different embodiment not illustrated, each actuator 76 is configured to move all the sealing heads 56 and 57 to and from the rest position along the direction D2.

[0069] According to a possible embodiment, each actuator 76 comprises one single motor which performs both the movement along the direction D1 and the movement along the direction D2; alternatively, each actuator 76 comprises a first motor which performs the movement along the direction D1 and a second motor separate and independent from the first motor which performs the movement along the direction D2.

[0070] As illustrated in Figure 21, in the transfer station S2 a pushing element 77 and an accompanying element 78 are arranged which carry out the transfer of two groups 14 of cigarettes next to one another from a pair of pockets 36 next to one another of the forming conveyor 37 to a pair of pockets 45 next to one another of the wrapping drum 43. The pushing element 77 and the accompanying element 78 always remain in the transfer station S2 while the forming conveyor 37 and the wrapping drum 43 move along the corresponding paths P1 and P2 so as to cyclically vary the corresponding pockets 36 and 45 which are standing still in transfer station S2. The pushing element 77 and the accompanying element 78 move in a mutually synchronized manner to "pinch" the two groups 14 of cigarettes next to one another to be transferred and thus allowing to maintain complete control over the position and stability of the two groups 14 of cigarettes.

[0071] As illustrated in Figure 21, in the transfer station S7 a pushing element 79 and an accompanying element 80 are arranged which carry out the transfer of two groups 14 of cigarettes next to one another and coupled to two wrapping sheets 18 from a pair of pockets 45 next to one another of the wrapping drum 43 to a pair of pockets 48 next to one another of the wrapping drum 46. The pushing element 79 and the accompanying element 80 always remain in the transfer station S7 while the wrapping drums 43 and 46 move along the corresponding wrapping paths P2 so as to cyclically vary the corresponding pockets 45 and 48 which are standing still in the S7 transfer station. The pushing element 79 and the accompanying element 80 move in a mutually synchronized manner to "pinch" the two groups 14 of cigarettes next to one another to be transferred and thus allowing to maintain complete control over the position and stability of the two groups 14 of cigarettes.

[0072] As illustrated in Figure 21, in the transfer station S4 a pushing element 81 and an accompanying element 82 are arranged which carry out the transfer of two groups 14 of cigarettes next to one another and coupled to two wrapping sheets 18 folded into a tube from a pair of pockets 48 next to one another of the wrapping drum 46 to a pair of pockets 42 next to one another of the wrapping drum 40. The pushing element 81 and the accompanying element 82 always remain in the transfer station S4 while the wrapping drums 46 and 40 move along the corresponding wrapping paths P2 and P4 so as to cyclically vary the corresponding pockets 48 and 42 which are standing still at transfer station S4. The pushing element 81 and the accompanying element 82 move in a mutually synchronized manner to "pinch" the two groups 14 of cigarettes next to one another to be transferred and thus allowing to maintain complete control over the position and stability of the two groups 14 of cigarettes.

[0073] As illustrated in Figure 22, in the transfer station S5 a pushing element 83 is arranged which carries out the transfer of two groups 14 of cigarettes next to one another and coupled to two wrapping sheets 18 folded into a tube from a pair of pockets 48 next to one another of the wrapping drum 46 to a pair of pockets 84 next to one another (schematically illustrated in Figure 20) of the wrapping conveyor 39. The pushing element 83 always remains in the transfer station S5 while the wrapping drum 40 and the wrapping conveyor 39 move along the corresponding wrapping paths P4 and P3 so as to cyclically vary the corresponding pockets 42 and 84 which are standing still in the transfer station S5. In the transfer station S5, the tube-like folding of the wrapping sheets 18 has already been completed and stabilized, therefore the pushing element 83 does not necessarily require the presence of a corresponding counter-pushing element since the tube-like folding of the wrapping sheets 18 contributes to maintaining stable the groups 14 of cigarettes (in fact, also the accompanying element 82 of the transfer station S4 could be omitted).

[0074] According to a preferred embodiment, the wrapping conveyor 39 comprises an annular conveyor belt, which is wound around two end pulleys (one of which is motorized), supports the pockets 84 and moves in a step-like manner to cyclically move the pockets 84 along the wrapping path P3.

[0075] In the inlet station S1 the cigarette filters 15 are arranged at the back (namely, the groups 14 of cigarettes are pushed onto the filters 15 to be extracted from the outlet mouths 35 of the hopper 34). In the transfer station S2 the cigarette filters 15 are arranged at the back (namely, the pushing element 77 pushes on the filters 15). In the transfer station S7 the cigarette filters 15 are arranged in front (namely, the pushing element 79 pushes on the opposite tips of the filters 15). In the transfer station S4 the cigarette filters 15 are arranged at the back (namely, the pushing element 81 pushes on the filters 15). In the transfer station S5 the cigarette filters 15 are arranged in front (namely, the pushing element 83 pushes on the tips opposite the filters 15).

[0076] As previously stated, the transfer station S7 comprises the pushing element 79 which is radially movable relative to the rotation axis 47 of the wrapping drum 46, is arranged on the outside of the wrapping drum 46, and is configured to push two groups 14 of cigarettes next to one another in two corresponding pockets 48 next to one another; moreover, the transfer station S7 comprises the accompanying element 80 which is radially movable relative to the rotation axis 47 of the wrapping drum 46, is arranged inside the wrapping drum 46, and is configured to accompany on the opposite side relative to the pushing element 79 the entry of two groups 14 of cigarettes next to one another into two corresponding pockets 48 next to one another.

[0077] As illustrated in Figure 30, each pair of pockets 48 next to one another of the wrapping drum 46 is formed inside a sliding compartment 85 (substantially parallelepiped-shaped) having a dividing wall 86 in the middle that is radially oriented and separates the two pockets 48 relative to one another; each dividing wall 86 has two folding profiles 87, which are arranged on opposite sides of the dividing wall 86 and extend along the entire length of the sliding compartment 85. The accompanying element 80 comprises two plates 88 which are configured to enter the pockets 48 and rest against a pair of corresponding groups 14 of cigarettes with the interposition of two corresponding wrapping sheets 18 and are mounted on respective rods 89 which are mutually connected (namely, mounted on the same support) so as to move together.

[0078] Each folding profile 87 is designed to fold by 90° a smaller wing 28 (illustrated in Figures 4 and 16) of each wrapping sheet 18 against the corresponding group 14 of cigarettes while the group 14 of cigarettes enters a respective pocket 48 formed in the sliding compartment 85. Each sliding compartment 85 also comprises, for each pocket 48, an outer wall 90 which delimits the pocket 48 on the opposite side of the dividing wall 86 (namely, the outer wall 90 is parallel and opposite to the dividing wall 86) and has its own folding profile 87 designed to fold by 90° a smaller wing 28 (illustrated in Figures 4 and 16) of each wrapping sheet 18 against the corresponding group 14 of cigarettes while the group 14 of cigarettes enters a respective pocket 48 formed in the sliding compartment 85. In other words, when a group 14 of cigarettes enters a respective pocket 48 obtained in the sliding compartment 85, the two smaller wings 28 (illustrated in Figures 4 and 16) of the wrapping sheet 18 fold by 90° against the group 14 of cigarettes due to the effect of the two folding profiles 87 which extend from the dividing wall 86 and from the outer wall 90.

[0079] According to a preferred embodiment, each pocket 41 of the wrapping drum 40 has two corresponding inner folding profiles to fold the smaller wings 29 (illustrated in Figures 4 and 16) of each wrapping sheet 18 by 90° against the corresponding group 14 of cigarettes.

[0080] As illustrated in Figure 31, the packing machine 33 comprises a cooling system 91 which is coupled to the two folding devices 52 and is configured to cool the fixed folding screw-like blades 53 and 54 of each folding device 52.

[0081] The cooling system 91 comprises for each folding screw-like blade 53 or 54 a heat exchanger 92 which is in contact with a surface of the folding screw-like blade 53 or 54 (centrally the same heat exchanger 92 can be shared by both screw-like blades 53 of the two folding devices 52 arranged next to one another). Obviously, each heat exchanger 92 is not in direct contact with an operating surface (namely, which directly performs the folds) of a corresponding folding screw-like blade 53 or 54, but is in contact with another surface of a corresponding folding screw-like blade 53 or 54 other than the operating surface (namely, which directly performs the folds).

[0082] Alternatively, each heat exchanger 92 may also not be arranged against a surface of a corresponding folding screw-like blade 53 or 54 but could be integrated into the corresponding folding screw-like blade 53 or 54 (or could form one single body with the corresponding folding screw-like blade 53 or 54).

[0083] Each heat exchanger 92 is crossed in use by a cooling fluid (typically water) and is therefore connected to a hydraulic circuit 93 provided with a circulation pump 94 and a radiator 95 (to transfer to the outside part of the heat from the cooling fluid). Generally, a (significant) portion of the hydraulic circuit 93 (in particular the portion of the hydraulic circuit 93 comprising the circulation pump 94 and the radiator 95) is arranged outside the packing machine 33 and is part of the services of the production plant in which the packing machine 33 is installed. It is important to note that the hydraulic circuit 93 is normally connected to the packing machine 33 independently of the cooling system 91 of the folding devices 52, since the cooling fluid of the hydraulic circuit 93 is used to cool the electric motors which move the various moving components of the packing machine 33.

[0084] According to a possible embodiment, each heat exchanger 92 has the shape of a parallelepiped plate.

[0085] According to a possible embodiment, the cooling system 91 comprises (at least) a temperature sensor 96 that measures a temperature of the fixed folding screw-like blades 53 and 54 and a control unit 97 configured to regulate the cooling power according to the temperature measured by the temperature sensor 96.

[0086] As illustrated in Figure 18, the packing machine 33 comprises a feeding device which, in a feeding station S13 (arranged between the inlet station S1 and the transfer station S2 relative to the movement direction of the forming conveyor 37), cyclically couples to the pockets 36 of the forming conveyor 37 (already containing the corresponding groups 14 of cigarettes) the reinforcing elements 19 (which are arranged around the groups 14 of cigarettes contained in the pockets 36). In the transfer station S2, when two groups 14 of cigarettes next to one another are extracted from a pair of pockets 36 next to one another, the two corresponding reinforcing elements 19 are pulled along with the two groups 14 of cigarettes, arranging themselves around the two groups 14 of the same cigarettes.

[0087] In the embodiment illustrated in the accompanying figures, the forming unit A and the wrapping unit B operate on a double line, namely, they process two groups 14 of cigarettes at a time; in other words, the forming conveyor 37, the wrapping conveyor 38, the wrapping conveyor 39, and the wrapping drum 40 operate on a double line, namely, they process two groups 14 of cigarettes at a time. Whereas the wrapping unit C operates on one single line, namely, it processes one single blank 32 at a time to obtain a pack 1 of cigarettes (containing two sealed wraps 3 next to one another) at a time. According to an alternative embodiment, at least part of the forming unit A and / or at least part of the wrapping unit B could operate on one single line, namely, they could process one single group 14 of cigarettes at a time (particularly when pack 1 of cigarettes made by the packing machine 1 is not of the "twin" type and therefore houses one single sealed wrap 3). In other words, at least a portion of the forming conveyor 37, the wrapping conveyor 38, the wrapping conveyor 39, and the wrapping drum 40 could operate on one single line, namely, they could process one single group 14 of cigarettes at a time.

[0088] According to a preferred, but not binding, embodiment, the movement of the various components (wrapping drums, feeding conveyors, pushing elements, movable folding devices...) of the packing machine 32 is achieved by means of respective electric motors which are mechanically independent from one another and are synchronized (namely, moved in a timed manner) virtually (namely, not by means of a physical constraint, but by means of a control constraint). Normally an electric motor is considered as reference ("master") and all the other electric motors ("slaves") follow the position of the reference electric motor ("master").

[0089] The packing machine 33 could be modified (in a very simple way) to produce standard wraps 3 (namely, unsealed and therefore devoid of heat-sealing) instead of sealed wraps 3.

[0090] The packing machine 33 could be modified (in a very simple way) to obtain packs 1 of cigarettes each containing one single sealed (or even unsealed) wrap 3, or packs 1 of cigarettes not of the "twin" type.

[0091] The embodiments described herein can be combined with one another without departing from the scope of the present invention.

[0092] The packing machine 33 described above has numerous advantages.

[0093] In the first place, the packing machine 33 described above allows to produce the packs 1 of cigarettes with a high production quality (namely, presenting extremely precise and squared folds of the wrapping sheet 18) even when operating at a high production speed (namely, with a high number of packs 1 of cigarettes produced per unit of time).

[0094] Furthermore, the packing machine 33 described above has high accessibility to all its components and thanks to this characteristic it is possible to quickly carry out the format change operations (namely, the adaptation operations to modify the characteristics of the pack 1 of cigarettes to be produced) . In fact, an operator who is in front of the packing machine 33 is able to reach by hand all the active parts of the packing machine 29 in a simple, fast and ergonomic way. In particular, an operator who is in front of the packing machine 33 can easily reach by hand the hopper 34, the forming conveyor 37, the wrapping conveyor 38, the wrapping conveyor 39, and the wrapping drums 40, 66 and 70.

[0095] The wrapping unit B described above allows to produce two sealed wraps 3, together, by simultaneously folding two wrapping sheets 18 around two corresponding groups 14 of cigarettes; in this way it is possible to significantly increase the productivity of the packing machine 33 particularly when a "twin" pack 1 of cigarettes is produced which houses two sealed packs 3 next to one another.

[0096] The wrapping unit B described above allows high productivity to be maintained in the long run thanks to the fact that the wrapping sheet 18 is folded into a tube around a group 14 of cigarettes while the group 14 of cigarettes is moved by the wrapping drums 43 and 46; in fact, the wrapping drums 43 and 46 have a reduced risk of blockage due to a wrapping sheet 18 or a group 14 of cigarettes which, by moving in an unwanted way, become stuck in the machinery and therefore the risk of undesired stops of the packing machine 33 due to blockage in the wrapping conveyor 38 is minimized.

[0097] The wrapping unit B described above ensures a high production quality by operating at a high production speed thanks to the fact that the wrapping sheet 18 is folded into a tube around a group 14 of cigarettes while the group 14 of cigarettes is moved from the wrapping drums 43 and 46; in fact, the wrapping drums 43 and 46 allow both the position of the wrapping sheet 18 and the position of the group 14 of cigarettes to be controlled with high precision.

[0098] Furthermore, the wrapping unit B described above allows to guarantee a high production quality by operating at a high production speed also thanks to the fact that in the area of the longitudinal folds the wrapping sheet 18 is always well spread and does not show any type of wrinkles; this result is obtained thanks to the presence of the cooling system 91 which cools the fixed folding screw-like blades 53 and 54 of the folding devices 52. In fact, by operating at a high production speed, the temperature of the sealing heads 56 and 57 of the sealing devices 55 is relatively high and in the long run the sealing heads 56 and 57 tend to heat up the fixed folding screw-like blades 53 and 54 and when the fixed folding screw-like blades 53 and 54 become too hot and tend to generate small unwanted wrinkles or in any case small unwanted deformations (if not real folding waste) on the parts of the wrapping sheet 18 with which they come into contact.

[0099] The embodiment illustrated in the attached figures refers to the manufacturing of a pack of cigarettes, but the present invention can also be applied, without substantial modifications, to the manufacturing of any other type of pack of smoking articles (for example a pack of cigars, a pack of electronic cigarettes of the liquid vaporization type, a pack of new generation cigarettes without tobacco combustion...) .LIST OF REFERENCE NUMBERS OF THE FIGURE

[0100] 1 pack of cigarettes 2 outer container 3 sealed wrap 4 lid 5 hinge 6 lower wall 7 front wall 8 rear wall 9 side walls 10 upper wall 11 front wall 12 rear wall 13 side walls 14 group of cigarettes 15 filter 16 extraction opening 17 closing label 18 wrapping sheet 19 reinforcing element 20 front wall 21 side walls 22 lower wall 23 rear wall 24 flaring 25 ends 26 ends 27 sealing fin 28 smaller wing 29 smaller wing 30 larger wing 31 larger wing 32 blank 33 packing machine 34 hopper 35 outlet mouths 36 pockets 37 forming conveyor 38 wrapping conveyor 39 wrapping conveyor 40 wrapping drum 41 rotation axis 42 pocket 43 wrapping drum 44 rotation axis 45 pocket 46 wrapping drum 47 rotation axis 48 pocket 49 folding device 50 sealing device 51 sealing heads 52 folding device 53 folding screw-like blades 54 folding screw-like blades 55 sealing device 56 outer sealing head 57 inner sealing head 58 feeding device 59 band of wrapping material 60 cutting member 61 cutting member 62 feeding drum 63 rotation axis 64 feeding drum 65 rotation axis 66 wrapping drum 67 pockets 68 rotation axis 69 feeding device 70 wrapping drum 71 pockets 72 rotation axis 73 transfer drum 74 pockets 75 rotation axis 76 actuator 77 pushing element 78 accompanying element 79 pushing element 80 accompanying element 81 pushing element 82 accompanying element 83 pushing element 84 pockets 85 sliding compartment 86 dividing wall 87 folding profiles 88 plates 89 rod 90 outer wall 91 cooling system 92 heat exchanger 93 hydraulic circuit 94 circulation pump 95 radiator 96 temperature sensor 97 control units P1 forming path P2 wrapping path P3 wrapping path P4 wrapping path S1 inlet station S2 transfer station S3 feeding station S4 transfer station S5 transfer station S6 transfer station S7 transfer station S8 transfer station S9 feeding station S10 transfer station S11 transfer station S12 transfer station S13 feeding station A forming unit B wrapping unit C wrapping unit D1 direction D2 direction

Claims

1. A wrapping unit (B) to produce two sealed wraps (3), together, by simultaneously folding two wrapping sheets (18) around two corresponding groups (14) of smoking articles; the wrapping unit (B) comprises: a wrapping conveyor (39), which is designed to move the two groups (14) of smoking articles next to one another and coupled to the two wrapping sheets (18) along a straight wrapping path (P3); two folding devices (52), each coupled to the wrapping conveyor (39) and arranged along the wrapping path (P3) in order to fold two opposite ends of a wrapping sheet (18) around a corresponding group (14) of smoking articles; and two sealing devices (55), each coupled to the wrapping conveyor (39) and arranged along the wrapping path (P3) downstream of the respective folding device (52) to form a seal on two sides of a wrapping sheet (18) folded around a corresponding group (14) of smoking articles; wherein each sealing device (55) comprises an outer sealing head (56) arranged on the outside of the wrapping conveyor (39) and an inner sealing head (57) arranged at the centre of the wrapping conveyor (39); wherein each sealing device (55) comprises an actuator (76) configured to move the two sealing heads (56, 57) between: a work position in which the two sealing heads (56, 57) have a first mutual distance which determines a compression of the corresponding group (14) of smoking articles, a moving position in which the two sealing heads (56, 57) have a second mutual distance which is greater than the first mutual distance and allows the corresponding group (14) of smoking articles to move along the wrapping path (P3), and a rest position in which the two sealing heads (56, 57) have a third mutual distance, which is greater than the second mutual distance; and wherein each actuator (76) is configured to move the two sealing heads (56, 57) between the work position and the moving position along a first direction (D1) perpendicular to the wrapping path (P3); wherein each actuator (76) is configured to move at least the inner sealing head (57) to and from the rest position along a second direction (D2) perpendicular to the first direction (D1) and to the wrapping path (P3).

2. The wrapping unit (B) according claim 1, wherein each actuator (76) is configured to move the sole inner sealing head (57) to and from the rest position along the second direction (D2) and is configured to move the outer sealing head (56) to and from the rest position along the first direction (D1).

3. The wrapping unit (B) according claim 1, wherein each actuator (76) is configured to move both sealing heads (56, 57) to and from the rest position along the second direction (D2).

4. The wrapping unit (B) according to claim 1, 2 or 3, wherein each actuator (76) comprises one single motor, which causes both the movement along the first direction (D1) and the movement along the second direction (D2).

5. The wrapping unit (B) according to claim 1, 2 or 3, wherein each actuator (76) comprises a first motor, which causes the movement along the first direction (D1), and a second motor, which is separate from and independent of the first motor and causes the movement along the second direction (D2).

6. The wrapping unit (B) according to one of the claims from 1 to 5, wherein each folding device (52) comprises fixed folding blades (53, 54), which are arranged along the wrapping conveyor (39).

7. The wrapping unit (B) according to one of the claims from 1 to 6, wherein: a cutting member (61) is provided, which is configured to cut one single band (59) of wrapping material in half in order to obtain, from the single band (59) of wrapping material, the two wrapping sheets (18) arranged in mutual contact; and the wrapping conveyor (39) is configured to move the groups (14) of smoking articles arranged at a mutual distance so that the groups (14) of smoking articles are centred relative to the corresponding wrapping sheets (18) arranged in mutual contact.

8. The wrapping unit (B) according to one of the claims from 1 to 7, wherein: the wrapping conveyor (39) has a step-wise law of movement alternating motion steps and stop steps; and each actuator (76) is configured to hold the sealing heads (56, 57) in the moving position during the motion steps of the wrapping conveyor (39) and to move the sealing heads (56, 57) from the moving position to the work position and vice versa during the stop steps of the wrapping conveyor (39).

9. The wrapping unit (B) according to one of the claims from 1 to 8, wherein each actuator (76) is configured to move the two sealing heads (56, 57) to the rest position when the wrapping unit (B) is stopped and, hence, the wrapping conveyor (39) is stopped.

10. The wrapping unit (B) according to one of the claims from 1 to 9, wherein: the straight wrapping path (P3) is horizontal; the first direction (D1) is horizontal and perpendicular to the wrapping path (P3); and the second direction (D2) is vertical and perpendicular to the first direction (D1) and to the wrapping path (P3).

11. A wrapping method to produce two sealed wraps (3), together, by simultaneously folding two wrapping sheets (18) around two corresponding groups (14) of smoking articles; the wrapping method comprises the steps of: moving, by means of a wrapping conveyor (39), the two groups (14) of smoking articles next to one another and coupled to the two wrapping sheets (18) along a straight and horizontal wrapping path (P3); folding, by means of two folding devices (52), each coupled to the wrapping conveyor (39) and arranged along the wrapping path (P3), two opposite ends of a wrapping sheet (18) around a corresponding group (14) of smoking articles; and forming, by means of two sealing devices (55), each coupled to the wrapping conveyor (39) and arranged along the wrapping path (P3) downstream of the respective folding device (52), a seal on two sides of a wrapping sheet (18) folded around a corresponding group (14) of smoking articles; wherein each sealing device (55) comprises an outer sealing head (56) arranged on the outside of the wrapping conveyor (39) and an inner sealing head (57) arranged at the centre of the wrapping conveyor (39); wherein each sealing device (55) comprises an actuator (76) configured to move the two sealing heads (56, 57) to: a work position in which the two sealing heads (56, 57) have a first mutual distance which determines a compression of the corresponding group (14) of smoking articles, a moving position in which the two sealing heads (56, 57) have a second mutual distance which is greater than the first mutual distance and allows the corresponding group (14) of smoking articles to move along the wrapping path (P3), and a rest position in which the two sealing heads (56, 57) have a third mutual distance which is greater than the second mutual distance; and wherein each actuator (76) is configured to move the two sealing heads (56, 57) between the work position and the moving position along a first direction (D1) perpendicular to the wrapping path (P3); the wrapping method is characterized in that each actuator (76) is configured to move at least the inner sealing head (57) to and from the rest position along a second direction (D2) perpendicular to the first direction (D1) and to the wrapping path (P3).