Manufacturing machine and manufacturing method for the production of a tubular element, in particular for a smoking article

Abstract

Manufacturing machine (4) and manufacturing method for the production of a tubular element (1), in particular for a smoking article. The following are provided: an input conveyor (5), which moves at least one seat (7) along an input path (P1); a wrapping conveyor (11), which moves at least one spindle (13), having the shape of an inner cavity of the tubular element (1), along a wrapping path (P2); a feeding station (S1) , where the seat (7) receives a wrapping sheet (3); a folding station (S3), where the seat (7) releases the wrapping sheet (3) to the spindle (13) thus folding the wrapping sheet (3) around the spindle (13) in a "U"-shape; and a folding device (36), which is permanently arranged in the folding station (S3), is independent of and separate from the input conveyor (5) and from the wrapping conveyor (11), and is configured to fold the previously "U"-folded wrapping sheet (3) in a tubular manner and around the spindle (13) by overlapping two opposite edges of the wrapping sheet (3) one on top of the other.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This patent application is related to Italian patent application No. 102022000017514 filed on August 24, 2022, the entire disclosure of which is incorporated herein by reference.TECHNICAL FIELD

[0002] The present invention relates to a manufacturing machine and to a manufacturing method for the production of a tubular element.

[0003] The present invention finds advantageous application to the production of a tubular element having a truncated cone shape and provided at one end with a filter, which is subsequently used for the manual production of a cigarette, to which the following disclosure will make explicit reference without thereby losing generality.PRIOR ART

[0004] Recently, partially empty tubular elements having a truncated cone shape and provided at one end with a filter have been proposed on the market of smoking articles, which are used for the manual production of a cigarette; in particular, a user no longer has to manually roll a cigarette paper (a long and complex operation requiring good manual ability to obtain a result only just acceptable in quality), but only needs to simply fill with tobacco a preformed tubular element through the open end.

[0005] However, to date, the production of these tubular elements having a truncated cone shape and provided at one end with a filter is still carried out manually or almost manually and therefore has very high production costs and does not allow to obtain significant quantities and results in a final product with a very variable and on average not optimal quality.

[0006] Patent application WO2021156816A1 describes a manufacturing machine for the production of a tubular element for a smoking article and having: an input drum that moves along an input path; a seat; a wrapping drum that moves along a wrapping path a spindle having the shape of an inner cavity of the tubular element; a feeding station where the seat receives a wrapping sheet; and a folding station where the seat releases the wrapping sheet to the spindle thus folding the wrapping sheet around the spindle in a "U"-shape.

[0007] In the manufacturing machine described in the patent application WO2021156816A1, the construction of the wrapping drum is relatively complex, since the wrapping drum must support a plurality of spindles, each coupled to two different movable folding elements having independent movements from one another.DESCRIPTION OF THE INVENTION

[0008] The object of the present invention is to provide a manufacturing machine and a manufacturing method for the production of a tubular element, in particular for a smoking article, which manufacturing machine and manufacturing method allow to achieve high productivity while ensuring high quality standards and are, at the same time, easy and inexpensive to implement.

[0009] According to the present invention, a manufacturing machine and a manufacturing method are provided for the production of a tubular element, in particular for a smoking article, according to what is claimed in the attached claims.

[0010] The claims describe preferred embodiments of the present invention forming an integral part of the present description.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] 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 perspective view of a tubular element having a truncated cone shape intended for the manual production of a cigarette; Figure 2 is a plan view of wrapping sheets used to form the tubular element of Figure 1; Figure 3 is a perspective view and with parts removed for clarity of a manufacturing machine which produces the tubular element of Figure 1; Figure 4 is a front view of the manufacturing machine of Figure 3; Figure 5 is a different perspective view and with parts removed for clarity of a portion of the manufacturing machine of Figure 3; Figure 6 is a perspective view and with parts removed for clarity of an input drum and a wrapping drum of the manufacturing machine of Figure 3; Figures 7 and 8 are two perspective views of a folding station arranged between the two drums of Figure 6 in two different operating moments; Figure 9 is a perspective view of a feeding drum, the input drum, and the wrapping drum of the manufacturing machine of Figure 3; Figure 10 is a perspective view of the input drum of the manufacturing machine of Figure 3; Fig. 11 is a perspective view and on an enlarged scale of a seat of the input drum and of a spindle of the wrapping drum in the folding station; and Figure 12 is a perspective view and on an enlarged scale of a spindle and of a countering element of the wrapping drum. PREFERRED EMBODIMENTS OF THE INVENTION

[0012] Number 1 in Figure 1 indicates, as a whole, a partially empty tubular element having a truncated cone shape and provided at one (narrower) end with a filter 2. The tubular element 1 is intended for the manual production of a cigarette by being filled with tobacco through the open end.

[0013] The tubular element is formed by a wrapping sheet 3 having a trapezoid shape (illustrated extended in Figure 2) which is wrapped upon itself into a tube until one end overlaps the other end; in particular, a permanent vinyl-based glue is interposed between the two overlapping ends and keeps the two overlapping ends joined together, thus stabilizing the tube-like folding of the wrapping sheet 3.

[0014] Number 4 in Figures 3 and 4 indicates, as a whole, a manufacturing machine (only partially illustrated) for the production of the tubular elements 1 described above. The manufacturing machine 4 has an intermittent motion, namely, its conveyors cyclically alternate motion phases and stop phases.

[0015] As illustrated in Figure 4, the manufacturing machine 4 comprises an input drum 5, which is arranged vertically and is mounted so as to rotate in a step-like manner around a horizontal rotation axis 6; in other words, the input drum 5 is driven into rotation around the rotation axis 6 with an intermittent motion, namely, a non-continuous motion which provides for a cyclical alternation of motion phases, in which the input drum 5 is in motion and stop phases, in which the input drum 5 is still. The input drum 5 supports four seats 7, each designed to receive a corresponding wrapping sheet 3; according to a different embodiment, not illustrated, the input drum 5 supports a different number of seats 7, for example three, five, six, eight... seats 7.

[0016] As illustrated in Figure 11, each seat 7 has a truncated cone shaped holding wall 8, which reproduces the shape of the wrapping sheets 3 and is designed to hold a corresponding wrapping sheet 3 by means of suction; namely, the holding wall 8 of each seat 7 has a plurality of small holes which can be connected to a suction source to hold a corresponding wrapping sheet 3, and can optionally be connected to a compressed air source to push a corresponding wrapping sheet 3 away. Furthermore, the holding wall 8 of each seat 7 has, at the centre, a truncated cone shaped groove 9, which reproduces in negative the shape of a tubular element 1. Each seat 7 is mounted in a fixed position on the input drum 5 so that each seat 7 never performs any type of movement relative to the input drum 5.

[0017] As illustrated in Figure 4, the rotation of the input drum 5 around the rotation axis 6 cyclically moves each seat 7 along a circular input path P1, which passes through: a feeding station S1 where the seat 7 receives a wrapping sheet 3, a gluing station S2 (illustrated in Figures 6-10) where the wrapping sheet 3 carried by seat 7 is glued (namely, it is provided with glue), and a folding station S3 (illustrated in Figures 6-10) where the wrapping sheet 3 is folded in a tube and then released (that is, it leaves the seat 7).

[0018] The input drum 5 is mounted on the frame of the manufacturing machine 4, as well as for rotating around the rotation axis 6, also for axially move along the rotation axis 6 (with an overall stroke of a few centimetres) between an exchange raised position (assumed only during the stop phases), in which the wrapping sheets 3 enter and exit the seats 7 and a lowered rotation position (assumed during the motion phases) in which the input drum 5 rotates around the rotation axis 6. In other words, the rotation of the input drum 5 around the rotation axis 6 is performed only and exclusively in the lowered rotation position, while during the stop phases the input drum 5 moves from the lowered rotation position to the raised exchange position and then returns from the raised exchange position to the lowered rotation position before the start of the next motion phase. The movement of the input drum 5 is generated by an actuator 10 (schematically illustrated in Figures 7-10) which uses fixed cams arranged inside the input drum 5 and / or an electric motor coupled to the input drum 5.

[0019] As illustrated in Figure 4, the manufacturing machine 4 comprises a wrapping drum 11, which is arranged vertically and is mounted so as to rotate, in a step-like manner around a horizontal rotation axis 12 (parallel to the rotation axis 5); in other words, the wrapping drum 11 is driven into rotation with an intermittent motion, namely, a non-continuous motion which provides for a cyclical alternation of motion phases, in which the wrapping drum 11 is in motion, and stop phases, in which the wrapping drum 11 is still. The wrapping drum 11 supports four spindles 13 (better illustrated in Figures 6, 9 and 11-12), each having the shape of a truncated cones like the shape of the inner cavity of the tubular elements 1 and is designed to receive a corresponding wrapping sheet 3 that is wrapped into a tube around the spindle 18; according to a different embodiment, not illustrated, the wrapping drum 11 supports a different number of spindles 13, for example three, five, six, eight... spindles 13.

[0020] Preferably, each spindle 13 is designed to hold a corresponding wrapping sheet 3 by means of suction; namely, an outer wall of each spindle 13 has a plurality of small holes which can be connected to a suction source to hold a corresponding wrapping sheet 3 and can optionally be connected to a compressed air source to push a corresponding wrapping sheet 3 away. According to a possible embodiment, the small holes of each spindle 13 are inclined towards the smaller base of spindle 13 (namely, towards the narrower end of spindle 13); in this way, when the small holes of each spindle 13 are fed with compressed air, they also generate an axial thrust which tends (helps) to withdraw a tubular element 1 from the spindle 13.

[0021] As illustrated in Figure 4, the rotation of the wrapping drum 11 around the rotation axis 12 cyclically moves each spindle 13 along a circular wrapping path P2 which passes through: the folding station S3, where the spindle 13 receives a wrapping sheet 3, which is wound in a tubular manner and around the spindle 13, from a seat 7 of the input drum 5, a stabilizing station S4, where the glue applied to the wrapping sheet 3 sets, thus stabilizing the tubular shape of the wrapping sheet 3, and a transfer station S5, where the tubular wrapping sheet 3 is released (namely, it leaves the spindle 13).

[0022] As better illustrated in Figure 12, the wrapping drum 11 comprises four countering bodies 14, each coupled to a corresponding spindle 13 and axially aligned with the corresponding spindle 13. Furthermore, the wrapping drum 11 comprises an actuator 15 (schematically illustrated in Figure 12) which axially moves each countering body 14 between a rest position (illustrated in Figure 12), in which the countering body 14 is far from the corresponding spindle 13 in order to allow a wrapping sheet 3 to be folded in a tubular manner around the spindle 13 in the folding station S3 and to allow a tubular element 1 to be released in the transfer station S5 and a work position, in which the countering body 14 presses against the spindle 13 in the overlapping area between two edges of the wrapping sheet 3 wound in a tubular manner so as to exert a pressure which favours optimal gluing between the two edges.

[0023] As illustrated in Figure 4, the manufacturing machine 4 comprises an insertion drum 16 which is arranged vertically and is mounted so as to rotate, in a step-like manner around a horizontal rotation axis 17 (parallel to the rotation axis 12); in other words, the insertion drum 16 is driven into rotation with an intermittent motion, namely, a non-continuous motion which provides for a cyclical alternation of motion phases, in which the insertion drum 16 is in motion, and of stop phases, in which the insertion drum 16 is still. The insertion drum 16 supports four pockets 18 (only partially illustrated), each having a tubular shape and is configured to hold a corresponding tubular element 1 by engaging the tubular element 1 from the outside (namely, the tubular element 1 enters the pocket 18 which reproduces in negative the outer shape of the tubular element 1); according to a different embodiment not illustrated, the insertion drum 16 supports a different number of pockets 18, for example three, five, six, eight... pockets 18.

[0024] Each pocket 18 is designed to hold a corresponding tubular element 1 by means of suction; that is, an inner wall of each pocket 18 has a plurality of small holes which can be connected to a suction source to hold a corresponding tubular element 1 and can optionally be connected to a compressed air source to push a corresponding tubular element 1 away. According to a possible embodiment, the small holes of each pocket 18 are inclined towards the larger base (namely, towards the wider end); in this way, when the small holes of each pocket 18 are fed with compressed air, they also generate an axial thrust which tends (helps) to withdraw a tubular element 1 from the pocket 18.

[0025] Each pocket 18 is movably mounted on the insertion drum 16 to radially move, relative to the insertion drum 16, between an expanded exchange position in which the pocket 18 receives and releases a corresponding tubular element 1 and a contracted rotation position (illustrated in the attached figures); in particular, in the exchange position each pocket 18 is (radially) further from the insertion drum 16 while in the rotation position each pocket 18 is (radially) closer to the insertion drum 16. It is important to emphasize that all the pockets 18 always radially move together and in the same way, namely, all the pockets 18 perform the same radial movement in a synchronized manner. The movement of the pockets 18 relative to the insertion drum 16 is generated by an actuator 19 (illustrated schematically in Figure 4) which uses fixed cams arranged inside the insertion drum 16 and / or electric motors carried by the insertion drum 16. In the attached figures, the pockets 18 are only partially visible as they are in the exchange position which keeps them almost completely inside the insertion drum 16.

[0026] As illustrated in Figure 4, the rotation of the insertion drum 16 around the rotation axis 17 cyclically moves each pocket 18 along a circular insertion path P3 which passes through: the transfer station S5, where the pocket 18 receives a tubular element 1 from a spindle 13 of the wrapping drum, an insertion station S6 , where a filter 2 is inserted into the tubular element 1, and a transfer station S7, where the tubular element 1 provided with the filter 2 is released (namely, it leave pocket 18) .

[0027] As illustrated in Figure 3, the manufacturing machine 4 comprises a linear output conveyor 20 which receives the tubular elements 1 provided with the filters 2 and moves the tubular elements 1 provided with the filters 2 along a linear output path P4. According to a preferred embodiment, the output conveyor 20 is a belt conveyor and comprises a conveyor belt which is closed in a loop around two end pulleys and supports a plurality of housing elements, each containing a series of pockets designed to house the tubular elements 1.

[0028] As illustrated in Figure 3, a transfer drum 21 is interposed between the output conveyor 20 and the feeding drum 16, which is arranged vertically and is mounted so as to rotate in a step-like manner around a horizontal rotation axis 22 (parallel to the rotation axis 17); in other words, the transfer drum 21 is driven into rotation with an intermittent motion, namely, a non-continuous motion which provides for a cyclical alternation of motion phases, in which the transfer drum 21 is in motion, and stop phases, in which the transfer drum 21 is still.

[0029] The transfer drum 21 supports two holding heads 23, each configured to engage, from the inside, and therefore hold a corresponding tubular element 1 (namely, each holding head 23 fits inside a corresponding tubular element 1 and reproduces, in positive, the inner shape of the tubular element 1); according to a different embodiment not illustrated, the transfer drum 21 supports a different number of holding heads 23, for example three, five, six, eight... holding heads 23. Each holding head 23 is designed to hold a corresponding tubular element 1 by means of suction; namely, an outer wall of each holding head 23 has a plurality of small holes which can be connected to a suction source to hold a corresponding tubular element 1 and can optionally be connected to a compressed air source to push a corresponding tubular element 1 away. According to a possible embodiment, the small holes of each holding head 23 are inclined towards the smaller base (namely, towards the narrower end); in this way, when the small holes of each holding head 23 are fed with compressed air, they also generate an axial thrust which tends (helps) to withdraw a tubular element 1 from the holding head 23.

[0030] As illustrated in Fig. 4, the rotation of the transfer drum 21 around the rotation axis 22 cyclically moves each holding head 23 along a circular transfer path P5 that moves the holding head 23 between the transfer station S7, where the holding head 23 receives a tubular element 1 from a pocket 18 of the insertion drum 16 and the output conveyor 20, where the holding head 23 releases the tubular element 1. According to a preferred, but not binding, embodiment, each holding head 23 also performs a radial movement relative to the transfer drum 21 so that the holding head 23 can approach the insertion drum 16 to facilitate the holding of a tubular element 1 and can subsequently approach the output conveyor 20 to facilitate the releasing of a tubular element 1.

[0031] As illustrated in Figures 3 and 4, the manufacturing machine 4 comprises a feeding system 24 which unwinds a paper band 25 (illustrated in Figure 2) from a reel to a cutting station S8, where a cutting device 26 cyclically performs a transverse cut of the paper band 25 to separate a succession of wrapping sheets 3 from the same paper band 25 (as illustrated in Figure 2). The cutting device 26 comprises a knife which, in order to cut the paper band 25, is cyclically moved perpendicular to the paper band 25 by a first actuator. Furthermore, the cutting device 26 comprises a second actuator which varies the inclination of the knife relative to the paper band 25 between one cut and the next (namely, rotates the knife around a rotation axis perpendicular to the laying plane of the paper band 25) so as to cyclically alternate the direction of the cut; in this way, it is possible to separate a succession of truncated cone shaped wrapping sheets 3 from the rectangular paper band 25 without producing scraps (namely, residual waste of the paper band 25 after cutting) as illustrated in Figure 2.

[0032] A feeding drum 27 (better illustrated in Figure 9) is interposed between the cutting device 26 and the input drum 5, it is arranged vertically and is mounted to rotate in a step-like manner around a horizontal rotation axis 28 (parallel to the rotation axis 6); in other words, the feeding drum 27 is driven into rotation with an intermittent motion, namely, a non-continuous motion which provides for a cyclical alternation of motion phases, in which the feeding drum 27 is in motion, and of stop phases, in which the feeding drum 27 is still. The feeding drum 27 supports two holding heads 29 (illustrated in Figures 6 and 9), each having a truncated cone shape and is configured to hold a corresponding wrapping sheet 3 by suction; according to a different embodiment not illustrated, the feeding drum 27 supports a different number of holding heads 29, for example three, five, six, eight... holding heads 29.

[0033] As illustrated in Fig. 4, the rotation of the feeding drum 27 around the rotation axis 28 cyclically moves each holding head 29 along a circular feeding path P6, which moves the holding head 29 between the cutting station S8, where the holding head 29 receives a newly cut wrapping sheet 3, and the feeding station S1 where the holding head 29 releases the wrapping sheet 3 to a seat 7 of the input drum 5.

[0034] The input drum 27 could be mounted on the frame of the manufacturing machine 4, as well as for rotating around the rotation axis 28, also for axially moving along the rotation axis 28 (with an overall stroke of a few centimetres) between a lowered exchange position (assumed only during the stop phases), in which the wrapping sheets 3 enter and exit the holding heads 29 and a raised rotation position (assumed during the motion phases), in which the input drum 27 rotates around to the rotation axis 28. Namely, the rotation of the input drum 27 around the rotation axis 28 is performed only and exclusively in the raised rotation position, while during the stop phases the input drum 27 moves from the raised rotation position to the lowered exchange position and then returns from the lowered exchange position to the raised rotation position before the start of the next motion phase. The movement of the input drum 27 is generated by an actuator which uses fixed cams arranged inside the input drum 27 and / or an electric motor coupled to the input drum 27.

[0035] The holding heads 29 are mounted on the input drum 27 so as to rotate relative to the input drum 27 around respective rotation axes parallel to the rotation axis 28 of the input drum 27.

[0036] As illustrated in Figure 4, the gluing station S2 comprises a spray gluing device 30 (namely, provided with gluing nozzles) which applies glue to a wrapping sheet 3 carried by the seat 7 while the seat 7 is standing still in the gluing station S2; namely, the gluing device 30 is coupled to the input conveyor 5 and is configured to deposit glue along an edge of the wrapping sheet 3 carried by each seat 7 while the seat 7 is standing still in the gluing station S2. According to a preferred embodiment, the gluing station S2 is arranged in an area of the input drum 5 where the seats 7 stop, so that the seats 7 are always still for a given time in the gluing station S2. While a seat 7 is still in the gluing station S2, the gluing device 30 (or rather the nozzles of the gluing device 30) move radially to deposit the glue along one edge of each wrapping sheet 3; namely, the law of movement followed by the gluing device 30 during the stopping of a seat 7 in the gluing station S2 is such that the glue sprayed by the gluing device 30 is deposited along one edge of each wrapping sheet 3. According to an alternative embodiment, the gluing device 30 does not perform any movement and is capable of depositing the glue along an entire edge of each wrapping sheet 3 due to a plurality of aligned nozzles.

[0037] As illustrated in Figures 9 and 10, the gluing device 30 comprises a spraying head 31 configured to deposit glue and an actuator 32 configured to move the spraying head 31 while depositing the glue and along a straight and radially (namely, perpendicular to the rotation axis 6 and to the input path P1) oriented gluing path; namely, the gluing path is transverse to the input path P1 generated by the input conveyor 5 to the seats 7. Preferably, the actuator 32 of the gluing device 30 comprises a track 33 oriented parallel to the gluing path, a slide 34 which slides along the track 33 and supports the spraying head 31 by means of an "L"-shaped bracket 35, and a motor which controls the position of the slide 34 along the track 33.

[0038] As illustrated in Figures 7 and 8, in the folding station S3 a folding device 36 is arranged, which is still in the folding station S3 (namely, it is mounted neither on the input drum 5 nor on the wrapping drum 11) and cyclically cooperates with all the spindles 13 of the wrapping drum 11 to wind a respective wrapping sheet 3 around a corresponding spindle 13 standing still in the folding station S3. In particular, the folding device 36 comprises two folding elements 37 and 38, which are arranged on opposite sides of a spindle 13 standing still in the folding station S3 (namely, the folding element 37 is arranged to the right of the spindle 13 while the folding element 38 is arranged to the left of the spindle 13) and are movable independently of one another relative to the spindle 13 so as to move between a standby position (illustrated in Figure 7), in which the folding elements 37 and 38 are (relatively) far apart from the spindle 13 (and do not touch the wrapping sheet 3) and a folding position (illustrated in Figure 8), in which the folding elements 37 and 38 are in substantial in contact with the spindle 13 (and fold the wrapping sheet 3 around the spindle 13).

[0039] According to a preferred embodiment, the folding elements 37 and 38 are mounted on the frame of the manufacturing machine 4 to rotate around a common rotation axis 39 in an independent manner from one another. Namely, each folding element 37 or 38 is supported by a corresponding arm which is hinged to rotate around the common rotation axis 39. In particular, as illustrated in Figure 4, two different actuators 40 and 41 are provided (typically two electric motors) which transmit the movement to the folding elements 37 and 38 by means of two respective arms 42 and 43.

[0040] In use, in the folding station S3 a spindle 13 of the wrapping drum 11 couples with a respective seat 7 of the input drum 5 by being inserted into the groove 9 of the seat 7 and consequently causing the "U"-shaped folding of the wrapping sheet 3, held by the seat 7, around the spindle 13 (as illustrated in Figure 11); as soon as the wrapping sheet 3 is folded in a "U"-shape around the spindle 13, the folding device 36 intervenes and completes the tube-like wrapping of the wrapping sheet 3 around the spindle 13 by first moving the folding element 37 between the standby position and the folding position to fold a first edge of the "U"-folded wrapping sheet 3 against the spindle 13 and then subsequently moving the folding element 38 between the waiting position and the folding position to fold a second edge of the "U"-folded wrapping sheet 3 against the spindle 13 and on top the first previously folded flap.

[0041] As illustrated in Figures 3, 4 and 5, an inserting device 44 is arranged in the insertion station S6, which is designed to insert a filter 2 into a tubular element 1 carried by a pocket 18 of the insertion drum 16 essentially still at the insertion station S6. The inserting device 44 comprises a tubular inserting body 45 having a truncated cone shape, which is designed to be inserted inside a tubular element 1 (carried by a pocket 18 of the insertion drum 16) and therefore to receive on its inside a filter 2, which is pushed along the entire inserting body 45 until it comes out of the inserting body 45 to fit inside the tubular element 1 that surrounds the inserting body 45. In other words, in the insertion station S6 the inserting body 45 is arranged inside the tubular element 1 so that a wider (larger) input end of the inserting body 45 is arranged at the wider (larger) end of the tubular element 1 and that a narrower (smaller) output end of the inserting body 45 is arranged inside the tubular element 1 and near the narrower (smaller) end of the tubular element 1 (namely, where the filter 2 is to be arranged). Once the inserting body 45 has been placed inside the tubular element 1, the filter 2 is pushed along the entire inserting body 45 thus entering from the wider (larger) input end of the inserting body 45 and exiting from the narrower (smaller) output end of the inserting body 45: when the filter comes out of the narrower (smaller) output end of the inserting body 45 it is inside the tubular element 1 in its final position and by widening by elastic return (no longer being radially compressed by the inserting body 45) is arranged (permanently) by interference inside the tubular element 1.

[0042] The inserting device 44 comprises a pushing element 46 (provided with reciprocating movement along a vertical direction) which pushes the filter 2 along the whole inserting body 45 by entering from the wider (larger) input end of the inserting body 45 and exiting from the narrower (small) output end of the inserting body 45. According to a further embodiment, the pushing element 46 could enter from the wider (large) input end of the inserting body 45 and arrive at the narrower (small) output end of the inserting body 45; in other words, in said embodiment it is only the filter 2 that emerges from the inserting body 4. In particular, the pushing element 46 is vertically and alternately moved by an actuator 47 which is preferably provided with an electric motor.

[0043] According to a preferred embodiment illustrated in the attached figures, between the inserting body 45 and the pushing element 46 a feeding drum 48 is interposed, which is arranged horizontally and is mounted so as to rotate in a step-like manner around a vertical rotation axis 49 (perpendicular to the rotation axis 17); in other words, the feeding drum 48 is driven into rotation with an intermittent motion, namely, a non-continuous motion which provides for a cyclical alternation of motion phases, in which the feeding drum 48 is in motion, and of stop phases, in which the feeding drum 48 stops. The feeding drum 48 supports sixteen pockets 50, each designed to receive a corresponding filter 2 and is axially oriented, and passes through the feeding drum 48 (that is, passes through feeding drum 48 from side to side); according to a different embodiment not illustrated, the feeding drum 48 supports a different number of pockets 50, for example eight, twelve, twenty-four... pockets 50.

[0044] As better illustrated in Figure 3, the rotation of the feeding drum 48 around the rotation axis 49 cyclically moves each pocket 50 along a circular feeding path that passes through a loading station S9 where the pocket 50 receives a filter 2 and the insertion station S6 where the pocket 50 releases the filter 2 that is then inserted (as previously described) in a tubular element 1 carried by a pocket 18 of the insertion drum 16. In the loading station S9 a feeding device 51 terminating in a vertically oriented feeding channel 51 inserts the filters 2 into the corresponding pockets 50 of the feeding drum 48; on the other hand, in the insertion station S6 the pushing element 46 (which begins its stroke above the feeding drum 48) axially (vertically) extracts a filter 2 from a pocket 50 to push the filter 2 through the inserting body 45 until the filter 2 fits into a tubular element 1 carried by a pocket 18 of the insertion drum 16 .

[0045] The operation of the manufacturing machine 4 is described in the following with reference to the manufacturing of a single tubular element 1.

[0046] As illustrated in Figure 2, initially, the paper band 25 is unwound from the reel and moved to the cutting station S8 where the knife (by cutting the paper band 25 transversely) separates a wrapping sheet 3 from the paper band 25 having a truncated cone shape; the wrapping sheet 3 is gripped immediately before cutting by a holding head 29 which subsequently accompanies the wrapping sheet 3 along the feeding path P6 and up to the feeding station S1 where the wrapping sheet 3 is released, by the holding head 29 of the feeding drum 27, to a seat 7 of the input drum 5.

[0047] A holding head 29 of the feeding drum 27 arrives at the feeding station S1 together with a seat 7 of the input drum 5 which is in the lowered rotation position (assumed during the motion phases); once both the holding head 29 of the feeding drum 27 and the seat 7 of the input drum 5 are standing still in the feeding station S1, the input drum 5 axially slides to move from the lowered rotation position (assumed during the motion phases) to the raised exchange position (assumed only during the stop phases) thus bringing the seat 7 into contact with the holding head 29 and thus allowing the seat 7 to remove the wrapping sheet 3 from the holding head 29. Once the seat 7 has removed the wrapping sheet 3 from the holding head 29, the input drum 5 axially slides to move from the raised exchange position to the lowered rotation position and therefore a further rotation of the input drum 5 may be performed.

[0048] It is important to underline that the wrapping sheets 3 are alternately separated from the paper band 25 with two opposite orientations (as illustrated in Figure 2); accordingly, each holding head 29 is mounted in a rotary manner relative to the feeding drum 27 to rotate relative to the feeding drum 27 around its own rotation axis parallel to the rotation axis 28 of the feeding drum 27 so as to present the wrapping sheets 3 always with the same rotation in the feeding station S1. In other words, the two holding heads 29 receive a respective wrapping sheet 3 in the cutting station S8 with two different (opposite) orientations and arrange the respective wrapping sheet 3 in the feeding station S1 always with the same orientation due to the fact that the two holding heads 29 perform respective 180° rotations, which are different from one another, around the respective rotation axes between the cutting station S8 and the feeding station S1.

[0049] For example, between the cutting station S8 and the feeding station S1 one holding head 23 of the feeding drum 27 performs no rotation relative to the feeding drum 27 whereas the other holding head 23 of the feeding drum 27 rotates upon itself with a 180° rotation relative to the feeding drum 27; alternatively, between the cutting station S8 and the feeding station S1 a holding head 23 of the feeding drum 27 rotates upon itself by 90° in a clockwise direction relative to the feeding drum 27 while the other holding head 23 of the feeding drum 27 rotates upon itself by 90° in a counterclockwise direction relative to the feeding drum 27.

[0050] Once the seat 7 has received the wrapping sheet 3 in the feeding station S1, the rotation of the input drum 5 around the rotation axis 6 brings the seat 7 to pass through (thus stopping in) the gluing station S2, where the gluing device 30 deposits glue on an edge of the wrapping sheet 3. Once the seat 7 has passed through (thus stopping in) the gluing station S2, the rotation of the input drum 5 around the rotation axis 6 brings the seat 7 into the folding station S3 where the seat 7 stops; at the same time, the rotation of the wrapping drum 11 around the rotation axis 12 brings a spindle 13 in the folding station S3 and above the seat 7, which is still (together with the entire input drum 5) in the lowered rotation position (namely, axially further from the wrapping drum 11). At this point, the seat 7 (together with the entire input drum 5) axially slides from the lowered rotation position to the raised exchange position (namely, axially closer to the wrapping drum 11) to bring the wrapping sheet 3 into contact with the spindle 13 (as illustrated in Figure 11); in particular, the axial sliding movement of the seat 7 (together with the entire input drum 5) pushes the wrapping sheet 3 into the groove 9 of the holding wall 8 of the seat 7 due to the presence of the spindle 13 thus causing a "U"-fold of the wrapping sheet 3 around the spindle 13 (as illustrated in Figure 11). In this step, the seat 7 releases the wrapping sheet 3 by interrupting the suction (which could also become an air jet to remove the wrapping sheet 3 from the seat 7) while, at the same time, the spindle 13 captures the wrapping sheet 3 by activating the suction.

[0051] After the wrapping sheet 3 has been folded in a "U"-shape around the spindle 13 in the folding station S3 and due to the effect of the relative movement between the seat 7 (together with the entire input drum 5) and the spindle 13, still in the folding station S3 the folding device 36 (or rather the two folding elements 37 and 38 of the folding device 36) folds the two edges of the "U"-folded wrapping sheet 3 one on top of the other to give the wrapping sheet 3 a tubular shape and then form a corresponding tubular element 1. The glue which was previously deposited on one of the two edges of the wrapping sheet 3 stabilizes the shape of the tubular element 1 as soon as the two edges overlap one another. During the tubular folding of the wrapping sheet 3, the countering body 14 associated with the spindle 13 remains in the rest position (relatively far from the spindle 13), while once the tubular folding of the wrapping sheet 3 is completed, the countering body 14 associated to the spindle 13 moves into the work position, in which the countering body 14 presses against the spindle 13 at the overlapping area between two edges of the wrapping sheet 3 wound in a tubular manner so as to exert a pressure which favours an optimal gluing between the two edges. The countering body 14 remains in the work position until the transfer station S5 where it returns to the rest position in order to allow the transfer of the tubular element 1 from the spindle 13 of the wrapping drum 11 to a pocket 18 of the insertion drum 16.

[0052] Once the manufacture of the tubular element 1 has been completed (namely, once the wrapping sheet 3 has been wound in a tubular manner around the spindle 13), the rotation of the wrapping drum 11 around the rotation axis 12 moves the spindle 13 carrying the tubular element 1 (namely, the wrapping sheet 3 folded in a tubular manner) through the stabilizing station S4, where the spindle 13 stops and the glue is able to adequately grip, thus stabilizing the shape of the tubular element 1. In this movement phase, the countering body 14 continues to press against the spindle 13 in the area of the overlapping portions so as to prevent the wrapping sheet 3, which forms the tubular element 1, from losing its folded shape by elastic return until the glue has sufficiently set.

[0053] Subsequently, the rotation of the wrapping drum 11 around the rotation axis 12 moves the spindle 13 carrying the tubular element 1 from the stabilizing station S4 to the transfer station S5; as soon as the spindle 13 carrying the tubular element 1 arrives at the transfer station S5, the countering body 14 moves to the rest position, thus freeing the tubular element 1. At this point, a pocket 18 of the insertion drum 16 which has arrived at the transfer station S5 together with the spindle 13 and is in the contracted rotational position, radially moves relative to the insertion drum 16 from the contracted rotational position to the expanded exchange position to incorporate the tubular element 1 carried by the spindle 13 inside the same, namely, to insert the tubular element 1 carried by the spindle 13 inside the same; at this point, the spindle 13 releases the tubular element 1 by interrupting its suction (which could also become an air jet to move the tubular element 1 away from the spindle 13) while at the same time the pocket 18 captures the tubular element 1 by activating its suction. Finally, the pocket 18 of the insertion drum 16 radially moves relative to the insertion drum 16 from the expanded exchange position to the contracted rotation position to withdraw the tubular element 1 (held by suction inside the pocket 18) from the spindle 13.

[0054] Once the pocket 18 has removed the tubular element 1 from the spindle 13 in the transfer station S5, the rotation of the insertion drum 16 around the rotation axis 13 moves the pocket 18 into the insertion station S6 where the pocket 18 is standing still. When the pocket 18 is standing still in the insertion station S6, the same pocket 18 (which is in the contracted rotation position) radially moves relative to the insertion drum 16 from the contracted rotation position to the expanded exchange position to couple to the inserting body 45; in this way, the inserting body 45 enters the pocket 18 and then enters the tubular element 1 housed in the pocket 18. At the same time, the pushing element 46 pushes a filter 2 along the entire inserting body 45 until the filter 2 comes out from the narrower (smaller) output end of the inserting body 45 (as described above) and then arrange (permanently) by interference the filter 2 inside the tubular element 1. When the insertion of the filter 2 into the tubular element 1 is completed, the pocket 18 of the insertion drum 16 radially moves relative to the insertion drum 16 from the expanded exchange position to the contracted rotation position to withdraw the tubular element 1 from the inserting body 45.

[0055] Once the pocket 18 of the insert drum 16 has returned to the contracted rotational position, the rotation of the insert drum 16 around the rotation axis 13 moves the pocket 18 from the insertion station S6 to the transfer station S7 where the pocket 18 is standing still. When the pocket 18 is standing still in the transfer station S7, the same pocket 18 (which is in the contracted rotation position) radially moves relative to the insertion drum 16 from the contracted rotation position to the expanded exchange position; at this point the tubular element 1 is released from the pocket 18 of the insertion drum 16 to the holding head 23 of the transfer drum 21.

[0056] Subsequently, the transfer drum 21 releases the tubular element 1 to the output conveyor 20.

[0057] By way of example, the filters 2 can be formed by a cardboard sheet 4 folded on itself or they can be formed by acetate fibres enclosed in a paper strip folded in a tubular manner.

[0058] According to a further embodiment, the tubular element 1 is devoid of the filter 2, namely, no filter 2 is inserted inside the tubular element 1.

[0059] According to a preferred embodiment, below the feeding drum 27, the wrapping drum 11, the insertion drum 16, and the transfer drum 21 four corresponding containers 53 are arranged, which are intended to receive any scraps which, once identified as waste, are abandoned, and fall into the containers 53 due to gravity.

[0060] According to a further embodiment, the manufacturing machine 4 also comprises a filling drum (for example interposed between the insertion drum 16 and the output conveyor 20) where powdered tobacco or another type of smoking material is fed into the tubular element 1.

[0061] In the embodiment illustrated in the attached figures, the seats 7, the pockets 18 and 50, the holding heads 23 and 29 and the spindles 13 are moved along the respective paths P1-P5 by rotary conveyors (the drums 5, 11, 16 , 21, 27 and 48); according to a different embodiment, not illustrated, some or all of the rotary conveyors (the drums 5, 11, 16, 21, 27 and 48) are replaced by corresponding linear conveyors (and therefore the respective paths P1-P5 are no longer circular but linear).

[0062] In the embodiment described above, the tubular element 1 has a truncated cone shape (namely, with a progressively increasing cross-section moving away from the filter 2); according to a different embodiment not illustrated, the tubular element 1 has a cylindrical shape (namely, a constant cross-section along its entire extension). Obviously also in this embodiment, the filter 2 can be shaped differently or it can be absent.

[0063] In the embodiment illustrated in the attached figures, the tubular element 1 is intended for the manual production of a cigarette; according to a different embodiment, the tubular element 1 (obviously without the filter 2 and having a truncated cone or cylindrical shape) has a different final destination, for example it could form a straw for drinks (namely, a straw for sipping a drink). Obviously, in order to make a drinking straw it is necessary for the wrapping sheet 3 to be made of a sufficiently impermeable paper or of another material that is impermeable.

[0064] The embodiments described herein can be combined with one another without departing from the scope of the present invention.

[0065] The manufacturing machine 4 described above has numerous advantages.

[0066] In the first place, the manufacturing machine 4 described above allows to achieve high hourly productivity (the nominal hourly productivity of the manufacturing machine 4 is of the order of 200-300 tubular elements 1 per minute) while guaranteeing a high-quality standard (namely, guaranteeing the forming of tubular elements 1 having a perfect shape without wrinkles or more or less accentuated deformations). This result is obtained, among other things, due to a particularly gentle, but at the same time very effective and efficient treatment of the wrapping sheets 3, which are never excessively mechanically stressed and at the same time always have a known and given position.

[0067] Furthermore, the manufacturing machine 4 is particularly compact and allows an operator who is in near the manufacturing machine 4 to reach by hand, all the various parts of the manufacturing machine 4 without having to perform unnatural movements.

[0068] Finally, the manufacturing machine 4 is relatively simple and inexpensive to implement.LIST OF REFERENCE NUMBERS OF THE FIGURE

[0069] 1tubular element 2filter 3wrapping sheet 4manufacturing machine 5input drum 6rotation axis 7seat 8holding wall 9groove 10actuator 11wrapping drum 12rotation axis 13spindles 14countering body 15actuator 16insertion drum 17rotation axis 18pockets 19actuator 20output conveyor 21transfer drum 22rotation axis 23holding heads 24feeding system 25paper band 26cutting device 27feeding drum 28rotation axis 29pockets 30gluing device 31spraying head 32actuator 33track 34slide 35bracket 36folding device 37folding element 38folding element 39rotation axis 40actuator 41actuator 42arm 43arm 44inserting device 45inserting body 46pushing element 47actuator 48feeding drum 49rotation axis 50pockets 51feeding device 52feeding channel 53containers P1input path P2wrapping path P3insertion path P4output path P5transfer path P6feeding path S1feeding station S2gluing station S3folding station S4stabilizing station S5transfer station S6insertion station S7transfer station S8cutting station S9loading station

Examples

Embodiment Construction

[0012]Number 1 in Figure 1 indicates, as a whole, a partially empty tubular element having a truncated cone shape and provided at one (narrower) end with a filter 2. The tubular element 1 is intended for the manual production of a cigarette by being filled with tobacco through the open end.

[0013]The tubular element is formed by a wrapping sheet 3 having a trapezoid shape (illustrated extended in Figure 2) which is wrapped upon itself into a tube until one end overlaps the other end; in particular, a permanent vinyl-based glue is interposed between the two overlapping ends and keeps the two overlapping ends joined together, thus stabilizing the tube-like folding of the wrapping sheet 3.

[0014]Number 4 in Figures 3 and 4 indicates, as a whole, a manufacturing machine (only partially illustrated) for the production of the tubular elements 1 described above. The manufacturing machine 4 has an intermittent motion, namely, its conveyors cyclically alternate motion phases and stop phases.

[0...

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This patent application is related to Italian patent application No. 102022000017514 filed on August 24, 2022, the entire disclosure of which is incorporated herein by reference.TECHNICAL FIELD

[0002] The present invention relates to a manufacturing machine and to a manufacturing method for the production of a tubular element.

[0003] The present invention finds advantageous application to the production of a tubular element having a truncated cone shape and provided at one end with a filter, which is subsequently used for the manual production of a cigarette, to which the following disclosure will make explicit reference without thereby losing generality.PRIOR ART

[0004] Recently, partially empty tubular elements having a truncated cone shape and provided at one end with a filter have been proposed on the market of smoking articles, which are used for the manual production of a cigarette; in particular, a user no longer has to manually roll a cigarette paper (a long and complex operation requiring good manual ability to obtain a result only just acceptable in quality), but only needs to simply fill with tobacco a preformed tubular element through the open end.

[0005] However, to date, the production of these tubular elements having a truncated cone shape and provided at one end with a filter is still carried out manually or almost manually and therefore has very high production costs and does not allow to obtain significant quantities and results in a final product with a very variable and on average not optimal quality.

[0006] Patent application WO2021156816A1 describes a manufacturing machine for the production of a tubular element for a smoking article and having: an input drum that moves along an input path; a seat; a wrapping drum that moves along a wrapping path a spindle having the shape of an inner cavity of the tubular element; a feeding station where the seat receives a wrapping sheet; and a folding station where the seat releases the wrapping sheet to the spindle thus folding the wrapping sheet around the spindle in a "U"-shape.

[0007] In the manufacturing machine described in the patent application WO2021156816A1, the construction of the wrapping drum is relatively complex, since the wrapping drum must support a plurality of spindles, each coupled to two different movable folding elements having independent movements from one another.DESCRIPTION OF THE INVENTION

[0008] The object of the present invention is to provide a manufacturing machine and a manufacturing method for the production of a tubular element, in particular for a smoking article, which manufacturing machine and manufacturing method allow to achieve high productivity while ensuring high quality standards and are, at the same time, easy and inexpensive to implement.

[0009] According to the present invention, a manufacturing machine and a manufacturing method are provided for the production of a tubular element, in particular for a smoking article, according to what is claimed in the attached claims.

[0010] The claims describe preferred embodiments of the present invention forming an integral part of the present description.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] 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 perspective view of a tubular element having a truncated cone shape intended for the manual production of a cigarette; Figure 2 is a plan view of wrapping sheets used to form the tubular element of Figure 1; Figure 3 is a perspective view and with parts removed for clarity of a manufacturing machine which produces the tubular element of Figure 1; Figure 4 is a front view of the manufacturing machine of Figure 3; Figure 5 is a different perspective view and with parts removed for clarity of a portion of the manufacturing machine of Figure 3; Figure 6 is a perspective view and with parts removed for clarity of an input drum and a wrapping drum of the manufacturing machine of Figure 3; Figures 7 and 8 are two perspective views of a folding station arranged between the two drums of Figure 6 in two different operating moments; Figure 9 is a perspective view of a feeding drum, the input drum, and the wrapping drum of the manufacturing machine of Figure 3; Figure 10 is a perspective view of the input drum of the manufacturing machine of Figure 3; Fig. 11 is a perspective view and on an enlarged scale of a seat of the input drum and of a spindle of the wrapping drum in the folding station; and Figure 12 is a perspective view and on an enlarged scale of a spindle and of a countering element of the wrapping drum. PREFERRED EMBODIMENTS OF THE INVENTION

[0012] Number 1 in Figure 1 indicates, as a whole, a partially empty tubular element having a truncated cone shape and provided at one (narrower) end with a filter 2. The tubular element 1 is intended for the manual production of a cigarette by being filled with tobacco through the open end.

[0013] The tubular element is formed by a wrapping sheet 3 having a trapezoid shape (illustrated extended in Figure 2) which is wrapped upon itself into a tube until one end overlaps the other end; in particular, a permanent vinyl-based glue is interposed between the two overlapping ends and keeps the two overlapping ends joined together, thus stabilizing the tube-like folding of the wrapping sheet 3.

[0014] Number 4 in Figures 3 and 4 indicates, as a whole, a manufacturing machine (only partially illustrated) for the production of the tubular elements 1 described above. The manufacturing machine 4 has an intermittent motion, namely, its conveyors cyclically alternate motion phases and stop phases.

[0015] As illustrated in Figure 4, the manufacturing machine 4 comprises an input drum 5, which is arranged vertically and is mounted so as to rotate in a step-like manner around a horizontal rotation axis 6; in other words, the input drum 5 is driven into rotation around the rotation axis 6 with an intermittent motion, namely, a non-continuous motion which provides for a cyclical alternation of motion phases, in which the input drum 5 is in motion and stop phases, in which the input drum 5 is still. The input drum 5 supports four seats 7, each designed to receive a corresponding wrapping sheet 3; according to a different embodiment, not illustrated, the input drum 5 supports a different number of seats 7, for example three, five, six, eight... seats 7.

[0016] As illustrated in Figure 11, each seat 7 has a truncated cone shaped holding wall 8, which reproduces the shape of the wrapping sheets 3 and is designed to hold a corresponding wrapping sheet 3 by means of suction; namely, the holding wall 8 of each seat 7 has a plurality of small holes which can be connected to a suction source to hold a corresponding wrapping sheet 3, and can optionally be connected to a compressed air source to push a corresponding wrapping sheet 3 away. Furthermore, the holding wall 8 of each seat 7 has, at the centre, a truncated cone shaped groove 9, which reproduces in negative the shape of a tubular element 1. Each seat 7 is mounted in a fixed position on the input drum 5 so that each seat 7 never performs any type of movement relative to the input drum 5.

[0017] As illustrated in Figure 4, the rotation of the input drum 5 around the rotation axis 6 cyclically moves each seat 7 along a circular input path P1, which passes through: a feeding station S1 where the seat 7 receives a wrapping sheet 3, a gluing station S2 (illustrated in Figures 6-10) where the wrapping sheet 3 carried by seat 7 is glued (namely, it is provided with glue), and a folding station S3 (illustrated in Figures 6-10) where the wrapping sheet 3 is folded in a tube and then released (that is, it leaves the seat 7).

[0018] The input drum 5 is mounted on the frame of the manufacturing machine 4, as well as for rotating around the rotation axis 6, also for axially move along the rotation axis 6 (with an overall stroke of a few centimetres) between an exchange raised position (assumed only during the stop phases), in which the wrapping sheets 3 enter and exit the seats 7 and a lowered rotation position (assumed during the motion phases) in which the input drum 5 rotates around the rotation axis 6. In other words, the rotation of the input drum 5 around the rotation axis 6 is performed only and exclusively in the lowered rotation position, while during the stop phases the input drum 5 moves from the lowered rotation position to the raised exchange position and then returns from the raised exchange position to the lowered rotation position before the start of the next motion phase. The movement of the input drum 5 is generated by an actuator 10 (schematically illustrated in Figures 7-10) which uses fixed cams arranged inside the input drum 5 and / or an electric motor coupled to the input drum 5.

[0019] As illustrated in Figure 4, the manufacturing machine 4 comprises a wrapping drum 11, which is arranged vertically and is mounted so as to rotate, in a step-like manner around a horizontal rotation axis 12 (parallel to the rotation axis 5); in other words, the wrapping drum 11 is driven into rotation with an intermittent motion, namely, a non-continuous motion which provides for a cyclical alternation of motion phases, in which the wrapping drum 11 is in motion, and stop phases, in which the wrapping drum 11 is still. The wrapping drum 11 supports four spindles 13 (better illustrated in Figures 6, 9 and 11-12), each having the shape of a truncated cones like the shape of the inner cavity of the tubular elements 1 and is designed to receive a corresponding wrapping sheet 3 that is wrapped into a tube around the spindle 18; according to a different embodiment, not illustrated, the wrapping drum 11 supports a different number of spindles 13, for example three, five, six, eight... spindles 13.

[0020] Preferably, each spindle 13 is designed to hold a corresponding wrapping sheet 3 by means of suction; namely, an outer wall of each spindle 13 has a plurality of small holes which can be connected to a suction source to hold a corresponding wrapping sheet 3 and can optionally be connected to a compressed air source to push a corresponding wrapping sheet 3 away. According to a possible embodiment, the small holes of each spindle 13 are inclined towards the smaller base of spindle 13 (namely, towards the narrower end of spindle 13); in this way, when the small holes of each spindle 13 are fed with compressed air, they also generate an axial thrust which tends (helps) to withdraw a tubular element 1 from the spindle 13.

[0021] As illustrated in Figure 4, the rotation of the wrapping drum 11 around the rotation axis 12 cyclically moves each spindle 13 along a circular wrapping path P2 which passes through: the folding station S3, where the spindle 13 receives a wrapping sheet 3, which is wound in a tubular manner and around the spindle 13, from a seat 7 of the input drum 5, a stabilizing station S4, where the glue applied to the wrapping sheet 3 sets, thus stabilizing the tubular shape of the wrapping sheet 3, and a transfer station S5, where the tubular wrapping sheet 3 is released (namely, it leaves the spindle 13).

[0022] As better illustrated in Figure 12, the wrapping drum 11 comprises four countering bodies 14, each coupled to a corresponding spindle 13 and axially aligned with the corresponding spindle 13. Furthermore, the wrapping drum 11 comprises an actuator 15 (schematically illustrated in Figure 12) which axially moves each countering body 14 between a rest position (illustrated in Figure 12), in which the countering body 14 is far from the corresponding spindle 13 in order to allow a wrapping sheet 3 to be folded in a tubular manner around the spindle 13 in the folding station S3 and to allow a tubular element 1 to be released in the transfer station S5 and a work position, in which the countering body 14 presses against the spindle 13 in the overlapping area between two edges of the wrapping sheet 3 wound in a tubular manner so as to exert a pressure which favours optimal gluing between the two edges.

[0023] As illustrated in Figure 4, the manufacturing machine 4 comprises an insertion drum 16 which is arranged vertically and is mounted so as to rotate, in a step-like manner around a horizontal rotation axis 17 (parallel to the rotation axis 12); in other words, the insertion drum 16 is driven into rotation with an intermittent motion, namely, a non-continuous motion which provides for a cyclical alternation of motion phases, in which the insertion drum 16 is in motion, and of stop phases, in which the insertion drum 16 is still. The insertion drum 16 supports four pockets 18 (only partially illustrated), each having a tubular shape and is configured to hold a corresponding tubular element 1 by engaging the tubular element 1 from the outside (namely, the tubular element 1 enters the pocket 18 which reproduces in negative the outer shape of the tubular element 1); according to a different embodiment not illustrated, the insertion drum 16 supports a different number of pockets 18, for example three, five, six, eight... pockets 18.

[0024] Each pocket 18 is designed to hold a corresponding tubular element 1 by means of suction; that is, an inner wall of each pocket 18 has a plurality of small holes which can be connected to a suction source to hold a corresponding tubular element 1 and can optionally be connected to a compressed air source to push a corresponding tubular element 1 away. According to a possible embodiment, the small holes of each pocket 18 are inclined towards the larger base (namely, towards the wider end); in this way, when the small holes of each pocket 18 are fed with compressed air, they also generate an axial thrust which tends (helps) to withdraw a tubular element 1 from the pocket 18.

[0025] Each pocket 18 is movably mounted on the insertion drum 16 to radially move, relative to the insertion drum 16, between an expanded exchange position in which the pocket 18 receives and releases a corresponding tubular element 1 and a contracted rotation position (illustrated in the attached figures); in particular, in the exchange position each pocket 18 is (radially) further from the insertion drum 16 while in the rotation position each pocket 18 is (radially) closer to the insertion drum 16. It is important to emphasize that all the pockets 18 always radially move together and in the same way, namely, all the pockets 18 perform the same radial movement in a synchronized manner. The movement of the pockets 18 relative to the insertion drum 16 is generated by an actuator 19 (illustrated schematically in Figure 4) which uses fixed cams arranged inside the insertion drum 16 and / or electric motors carried by the insertion drum 16. In the attached figures, the pockets 18 are only partially visible as they are in the exchange position which keeps them almost completely inside the insertion drum 16.

[0026] As illustrated in Figure 4, the rotation of the insertion drum 16 around the rotation axis 17 cyclically moves each pocket 18 along a circular insertion path P3 which passes through: the transfer station S5, where the pocket 18 receives a tubular element 1 from a spindle 13 of the wrapping drum, an insertion station S6 , where a filter 2 is inserted into the tubular element 1, and a transfer station S7, where the tubular element 1 provided with the filter 2 is released (namely, it leave pocket 18) .

[0027] As illustrated in Figure 3, the manufacturing machine 4 comprises a linear output conveyor 20 which receives the tubular elements 1 provided with the filters 2 and moves the tubular elements 1 provided with the filters 2 along a linear output path P4. According to a preferred embodiment, the output conveyor 20 is a belt conveyor and comprises a conveyor belt which is closed in a loop around two end pulleys and supports a plurality of housing elements, each containing a series of pockets designed to house the tubular elements 1.

[0028] As illustrated in Figure 3, a transfer drum 21 is interposed between the output conveyor 20 and the feeding drum 16, which is arranged vertically and is mounted so as to rotate in a step-like manner around a horizontal rotation axis 22 (parallel to the rotation axis 17); in other words, the transfer drum 21 is driven into rotation with an intermittent motion, namely, a non-continuous motion which provides for a cyclical alternation of motion phases, in which the transfer drum 21 is in motion, and stop phases, in which the transfer drum 21 is still.

[0029] The transfer drum 21 supports two holding heads 23, each configured to engage, from the inside, and therefore hold a corresponding tubular element 1 (namely, each holding head 23 fits inside a corresponding tubular element 1 and reproduces, in positive, the inner shape of the tubular element 1); according to a different embodiment not illustrated, the transfer drum 21 supports a different number of holding heads 23, for example three, five, six, eight... holding heads 23. Each holding head 23 is designed to hold a corresponding tubular element 1 by means of suction; namely, an outer wall of each holding head 23 has a plurality of small holes which can be connected to a suction source to hold a corresponding tubular element 1 and can optionally be connected to a compressed air source to push a corresponding tubular element 1 away. According to a possible embodiment, the small holes of each holding head 23 are inclined towards the smaller base (namely, towards the narrower end); in this way, when the small holes of each holding head 23 are fed with compressed air, they also generate an axial thrust which tends (helps) to withdraw a tubular element 1 from the holding head 23.

[0030] As illustrated in Fig. 4, the rotation of the transfer drum 21 around the rotation axis 22 cyclically moves each holding head 23 along a circular transfer path P5 that moves the holding head 23 between the transfer station S7, where the holding head 23 receives a tubular element 1 from a pocket 18 of the insertion drum 16 and the output conveyor 20, where the holding head 23 releases the tubular element 1. According to a preferred, but not binding, embodiment, each holding head 23 also performs a radial movement relative to the transfer drum 21 so that the holding head 23 can approach the insertion drum 16 to facilitate the holding of a tubular element 1 and can subsequently approach the output conveyor 20 to facilitate the releasing of a tubular element 1.

[0031] As illustrated in Figures 3 and 4, the manufacturing machine 4 comprises a feeding system 24 which unwinds a paper band 25 (illustrated in Figure 2) from a reel to a cutting station S8, where a cutting device 26 cyclically performs a transverse cut of the paper band 25 to separate a succession of wrapping sheets 3 from the same paper band 25 (as illustrated in Figure 2). The cutting device 26 comprises a knife which, in order to cut the paper band 25, is cyclically moved perpendicular to the paper band 25 by a first actuator. Furthermore, the cutting device 26 comprises a second actuator which varies the inclination of the knife relative to the paper band 25 between one cut and the next (namely, rotates the knife around a rotation axis perpendicular to the laying plane of the paper band 25) so as to cyclically alternate the direction of the cut; in this way, it is possible to separate a succession of truncated cone shaped wrapping sheets 3 from the rectangular paper band 25 without producing scraps (namely, residual waste of the paper band 25 after cutting) as illustrated in Figure 2.

[0032] A feeding drum 27 (better illustrated in Figure 9) is interposed between the cutting device 26 and the input drum 5, it is arranged vertically and is mounted to rotate in a step-like manner around a horizontal rotation axis 28 (parallel to the rotation axis 6); in other words, the feeding drum 27 is driven into rotation with an intermittent motion, namely, a non-continuous motion which provides for a cyclical alternation of motion phases, in which the feeding drum 27 is in motion, and of stop phases, in which the feeding drum 27 is still. The feeding drum 27 supports two holding heads 29 (illustrated in Figures 6 and 9), each having a truncated cone shape and is configured to hold a corresponding wrapping sheet 3 by suction; according to a different embodiment not illustrated, the feeding drum 27 supports a different number of holding heads 29, for example three, five, six, eight... holding heads 29.

[0033] As illustrated in Fig. 4, the rotation of the feeding drum 27 around the rotation axis 28 cyclically moves each holding head 29 along a circular feeding path P6, which moves the holding head 29 between the cutting station S8, where the holding head 29 receives a newly cut wrapping sheet 3, and the feeding station S1 where the holding head 29 releases the wrapping sheet 3 to a seat 7 of the input drum 5.

[0034] The input drum 27 could be mounted on the frame of the manufacturing machine 4, as well as for rotating around the rotation axis 28, also for axially moving along the rotation axis 28 (with an overall stroke of a few centimetres) between a lowered exchange position (assumed only during the stop phases), in which the wrapping sheets 3 enter and exit the holding heads 29 and a raised rotation position (assumed during the motion phases), in which the input drum 27 rotates around to the rotation axis 28. Namely, the rotation of the input drum 27 around the rotation axis 28 is performed only and exclusively in the raised rotation position, while during the stop phases the input drum 27 moves from the raised rotation position to the lowered exchange position and then returns from the lowered exchange position to the raised rotation position before the start of the next motion phase. The movement of the input drum 27 is generated by an actuator which uses fixed cams arranged inside the input drum 27 and / or an electric motor coupled to the input drum 27.

[0035] The holding heads 29 are mounted on the input drum 27 so as to rotate relative to the input drum 27 around respective rotation axes parallel to the rotation axis 28 of the input drum 27.

[0036] As illustrated in Figure 4, the gluing station S2 comprises a spray gluing device 30 (namely, provided with gluing nozzles) which applies glue to a wrapping sheet 3 carried by the seat 7 while the seat 7 is standing still in the gluing station S2; namely, the gluing device 30 is coupled to the input conveyor 5 and is configured to deposit glue along an edge of the wrapping sheet 3 carried by each seat 7 while the seat 7 is standing still in the gluing station S2. According to a preferred embodiment, the gluing station S2 is arranged in an area of the input drum 5 where the seats 7 stop, so that the seats 7 are always still for a given time in the gluing station S2. While a seat 7 is still in the gluing station S2, the gluing device 30 (or rather the nozzles of the gluing device 30) move radially to deposit the glue along one edge of each wrapping sheet 3; namely, the law of movement followed by the gluing device 30 during the stopping of a seat 7 in the gluing station S2 is such that the glue sprayed by the gluing device 30 is deposited along one edge of each wrapping sheet 3. According to an alternative embodiment, the gluing device 30 does not perform any movement and is capable of depositing the glue along an entire edge of each wrapping sheet 3 due to a plurality of aligned nozzles.

[0037] As illustrated in Figures 9 and 10, the gluing device 30 comprises a spraying head 31 configured to deposit glue and an actuator 32 configured to move the spraying head 31 while depositing the glue and along a straight and radially (namely, perpendicular to the rotation axis 6 and to the input path P1) oriented gluing path; namely, the gluing path is transverse to the input path P1 generated by the input conveyor 5 to the seats 7. Preferably, the actuator 32 of the gluing device 30 comprises a track 33 oriented parallel to the gluing path, a slide 34 which slides along the track 33 and supports the spraying head 31 by means of an "L"-shaped bracket 35, and a motor which controls the position of the slide 34 along the track 33.

[0038] As illustrated in Figures 7 and 8, in the folding station S3 a folding device 36 is arranged, which is still in the folding station S3 (namely, it is mounted neither on the input drum 5 nor on the wrapping drum 11) and cyclically cooperates with all the spindles 13 of the wrapping drum 11 to wind a respective wrapping sheet 3 around a corresponding spindle 13 standing still in the folding station S3. In particular, the folding device 36 comprises two folding elements 37 and 38, which are arranged on opposite sides of a spindle 13 standing still in the folding station S3 (namely, the folding element 37 is arranged to the right of the spindle 13 while the folding element 38 is arranged to the left of the spindle 13) and are movable independently of one another relative to the spindle 13 so as to move between a standby position (illustrated in Figure 7), in which the folding elements 37 and 38 are (relatively) far apart from the spindle 13 (and do not touch the wrapping sheet 3) and a folding position (illustrated in Figure 8), in which the folding elements 37 and 38 are in substantial in contact with the spindle 13 (and fold the wrapping sheet 3 around the spindle 13).

[0039] According to a preferred embodiment, the folding elements 37 and 38 are mounted on the frame of the manufacturing machine 4 to rotate around a common rotation axis 39 in an independent manner from one another. Namely, each folding element 37 or 38 is supported by a corresponding arm which is hinged to rotate around the common rotation axis 39. In particular, as illustrated in Figure 4, two different actuators 40 and 41 are provided (typically two electric motors) which transmit the movement to the folding elements 37 and 38 by means of two respective arms 42 and 43.

[0040] In use, in the folding station S3 a spindle 13 of the wrapping drum 11 couples with a respective seat 7 of the input drum 5 by being inserted into the groove 9 of the seat 7 and consequently causing the "U"-shaped folding of the wrapping sheet 3, held by the seat 7, around the spindle 13 (as illustrated in Figure 11); as soon as the wrapping sheet 3 is folded in a "U"-shape around the spindle 13, the folding device 36 intervenes and completes the tube-like wrapping of the wrapping sheet 3 around the spindle 13 by first moving the folding element 37 between the standby position and the folding position to fold a first edge of the "U"-folded wrapping sheet 3 against the spindle 13 and then subsequently moving the folding element 38 between the waiting position and the folding position to fold a second edge of the "U"-folded wrapping sheet 3 against the spindle 13 and on top the first previously folded flap.

[0041] As illustrated in Figures 3, 4 and 5, an inserting device 44 is arranged in the insertion station S6, which is designed to insert a filter 2 into a tubular element 1 carried by a pocket 18 of the insertion drum 16 essentially still at the insertion station S6. The inserting device 44 comprises a tubular inserting body 45 having a truncated cone shape, which is designed to be inserted inside a tubular element 1 (carried by a pocket 18 of the insertion drum 16) and therefore to receive on its inside a filter 2, which is pushed along the entire inserting body 45 until it comes out of the inserting body 45 to fit inside the tubular element 1 that surrounds the inserting body 45. In other words, in the insertion station S6 the inserting body 45 is arranged inside the tubular element 1 so that a wider (larger) input end of the inserting body 45 is arranged at the wider (larger) end of the tubular element 1 and that a narrower (smaller) output end of the inserting body 45 is arranged inside the tubular element 1 and near the narrower (smaller) end of the tubular element 1 (namely, where the filter 2 is to be arranged). Once the inserting body 45 has been placed inside the tubular element 1, the filter 2 is pushed along the entire inserting body 45 thus entering from the wider (larger) input end of the inserting body 45 and exiting from the narrower (smaller) output end of the inserting body 45: when the filter comes out of the narrower (smaller) output end of the inserting body 45 it is inside the tubular element 1 in its final position and by widening by elastic return (no longer being radially compressed by the inserting body 45) is arranged (permanently) by interference inside the tubular element 1.

[0042] The inserting device 44 comprises a pushing element 46 (provided with reciprocating movement along a vertical direction) which pushes the filter 2 along the whole inserting body 45 by entering from the wider (larger) input end of the inserting body 45 and exiting from the narrower (small) output end of the inserting body 45. According to a further embodiment, the pushing element 46 could enter from the wider (large) input end of the inserting body 45 and arrive at the narrower (small) output end of the inserting body 45; in other words, in said embodiment it is only the filter 2 that emerges from the inserting body 4. In particular, the pushing element 46 is vertically and alternately moved by an actuator 47 which is preferably provided with an electric motor.

[0043] According to a preferred embodiment illustrated in the attached figures, between the inserting body 45 and the pushing element 46 a feeding drum 48 is interposed, which is arranged horizontally and is mounted so as to rotate in a step-like manner around a vertical rotation axis 49 (perpendicular to the rotation axis 17); in other words, the feeding drum 48 is driven into rotation with an intermittent motion, namely, a non-continuous motion which provides for a cyclical alternation of motion phases, in which the feeding drum 48 is in motion, and of stop phases, in which the feeding drum 48 stops. The feeding drum 48 supports sixteen pockets 50, each designed to receive a corresponding filter 2 and is axially oriented, and passes through the feeding drum 48 (that is, passes through feeding drum 48 from side to side); according to a different embodiment not illustrated, the feeding drum 48 supports a different number of pockets 50, for example eight, twelve, twenty-four... pockets 50.

[0044] As better illustrated in Figure 3, the rotation of the feeding drum 48 around the rotation axis 49 cyclically moves each pocket 50 along a circular feeding path that passes through a loading station S9 where the pocket 50 receives a filter 2 and the insertion station S6 where the pocket 50 releases the filter 2 that is then inserted (as previously described) in a tubular element 1 carried by a pocket 18 of the insertion drum 16. In the loading station S9 a feeding device 51 terminating in a vertically oriented feeding channel 51 inserts the filters 2 into the corresponding pockets 50 of the feeding drum 48; on the other hand, in the insertion station S6 the pushing element 46 (which begins its stroke above the feeding drum 48) axially (vertically) extracts a filter 2 from a pocket 50 to push the filter 2 through the inserting body 45 until the filter 2 fits into a tubular element 1 carried by a pocket 18 of the insertion drum 16 .

[0045] The operation of the manufacturing machine 4 is described in the following with reference to the manufacturing of a single tubular element 1.

[0046] As illustrated in Figure 2, initially, the paper band 25 is unwound from the reel and moved to the cutting station S8 where the knife (by cutting the paper band 25 transversely) separates a wrapping sheet 3 from the paper band 25 having a truncated cone shape; the wrapping sheet 3 is gripped immediately before cutting by a holding head 29 which subsequently accompanies the wrapping sheet 3 along the feeding path P6 and up to the feeding station S1 where the wrapping sheet 3 is released, by the holding head 29 of the feeding drum 27, to a seat 7 of the input drum 5.

[0047] A holding head 29 of the feeding drum 27 arrives at the feeding station S1 together with a seat 7 of the input drum 5 which is in the lowered rotation position (assumed during the motion phases); once both the holding head 29 of the feeding drum 27 and the seat 7 of the input drum 5 are standing still in the feeding station S1, the input drum 5 axially slides to move from the lowered rotation position (assumed during the motion phases) to the raised exchange position (assumed only during the stop phases) thus bringing the seat 7 into contact with the holding head 29 and thus allowing the seat 7 to remove the wrapping sheet 3 from the holding head 29. Once the seat 7 has removed the wrapping sheet 3 from the holding head 29, the input drum 5 axially slides to move from the raised exchange position to the lowered rotation position and therefore a further rotation of the input drum 5 may be performed.

[0048] It is important to underline that the wrapping sheets 3 are alternately separated from the paper band 25 with two opposite orientations (as illustrated in Figure 2); accordingly, each holding head 29 is mounted in a rotary manner relative to the feeding drum 27 to rotate relative to the feeding drum 27 around its own rotation axis parallel to the rotation axis 28 of the feeding drum 27 so as to present the wrapping sheets 3 always with the same rotation in the feeding station S1. In other words, the two holding heads 29 receive a respective wrapping sheet 3 in the cutting station S8 with two different (opposite) orientations and arrange the respective wrapping sheet 3 in the feeding station S1 always with the same orientation due to the fact that the two holding heads 29 perform respective 180° rotations, which are different from one another, around the respective rotation axes between the cutting station S8 and the feeding station S1.

[0049] For example, between the cutting station S8 and the feeding station S1 one holding head 23 of the feeding drum 27 performs no rotation relative to the feeding drum 27 whereas the other holding head 23 of the feeding drum 27 rotates upon itself with a 180° rotation relative to the feeding drum 27; alternatively, between the cutting station S8 and the feeding station S1 a holding head 23 of the feeding drum 27 rotates upon itself by 90° in a clockwise direction relative to the feeding drum 27 while the other holding head 23 of the feeding drum 27 rotates upon itself by 90° in a counterclockwise direction relative to the feeding drum 27.

[0050] Once the seat 7 has received the wrapping sheet 3 in the feeding station S1, the rotation of the input drum 5 around the rotation axis 6 brings the seat 7 to pass through (thus stopping in) the gluing station S2, where the gluing device 30 deposits glue on an edge of the wrapping sheet 3. Once the seat 7 has passed through (thus stopping in) the gluing station S2, the rotation of the input drum 5 around the rotation axis 6 brings the seat 7 into the folding station S3 where the seat 7 stops; at the same time, the rotation of the wrapping drum 11 around the rotation axis 12 brings a spindle 13 in the folding station S3 and above the seat 7, which is still (together with the entire input drum 5) in the lowered rotation position (namely, axially further from the wrapping drum 11). At this point, the seat 7 (together with the entire input drum 5) axially slides from the lowered rotation position to the raised exchange position (namely, axially closer to the wrapping drum 11) to bring the wrapping sheet 3 into contact with the spindle 13 (as illustrated in Figure 11); in particular, the axial sliding movement of the seat 7 (together with the entire input drum 5) pushes the wrapping sheet 3 into the groove 9 of the holding wall 8 of the seat 7 due to the presence of the spindle 13 thus causing a "U"-fold of the wrapping sheet 3 around the spindle 13 (as illustrated in Figure 11). In this step, the seat 7 releases the wrapping sheet 3 by interrupting the suction (which could also become an air jet to remove the wrapping sheet 3 from the seat 7) while, at the same time, the spindle 13 captures the wrapping sheet 3 by activating the suction.

[0051] After the wrapping sheet 3 has been folded in a "U"-shape around the spindle 13 in the folding station S3 and due to the effect of the relative movement between the seat 7 (together with the entire input drum 5) and the spindle 13, still in the folding station S3 the folding device 36 (or rather the two folding elements 37 and 38 of the folding device 36) folds the two edges of the "U"-folded wrapping sheet 3 one on top of the other to give the wrapping sheet 3 a tubular shape and then form a corresponding tubular element 1. The glue which was previously deposited on one of the two edges of the wrapping sheet 3 stabilizes the shape of the tubular element 1 as soon as the two edges overlap one another. During the tubular folding of the wrapping sheet 3, the countering body 14 associated with the spindle 13 remains in the rest position (relatively far from the spindle 13), while once the tubular folding of the wrapping sheet 3 is completed, the countering body 14 associated to the spindle 13 moves into the work position, in which the countering body 14 presses against the spindle 13 at the overlapping area between two edges of the wrapping sheet 3 wound in a tubular manner so as to exert a pressure which favours an optimal gluing between the two edges. The countering body 14 remains in the work position until the transfer station S5 where it returns to the rest position in order to allow the transfer of the tubular element 1 from the spindle 13 of the wrapping drum 11 to a pocket 18 of the insertion drum 16.

[0052] Once the manufacture of the tubular element 1 has been completed (namely, once the wrapping sheet 3 has been wound in a tubular manner around the spindle 13), the rotation of the wrapping drum 11 around the rotation axis 12 moves the spindle 13 carrying the tubular element 1 (namely, the wrapping sheet 3 folded in a tubular manner) through the stabilizing station S4, where the spindle 13 stops and the glue is able to adequately grip, thus stabilizing the shape of the tubular element 1. In this movement phase, the countering body 14 continues to press against the spindle 13 in the area of the overlapping portions so as to prevent the wrapping sheet 3, which forms the tubular element 1, from losing its folded shape by elastic return until the glue has sufficiently set.

[0053] Subsequently, the rotation of the wrapping drum 11 around the rotation axis 12 moves the spindle 13 carrying the tubular element 1 from the stabilizing station S4 to the transfer station S5; as soon as the spindle 13 carrying the tubular element 1 arrives at the transfer station S5, the countering body 14 moves to the rest position, thus freeing the tubular element 1. At this point, a pocket 18 of the insertion drum 16 which has arrived at the transfer station S5 together with the spindle 13 and is in the contracted rotational position, radially moves relative to the insertion drum 16 from the contracted rotational position to the expanded exchange position to incorporate the tubular element 1 carried by the spindle 13 inside the same, namely, to insert the tubular element 1 carried by the spindle 13 inside the same; at this point, the spindle 13 releases the tubular element 1 by interrupting its suction (which could also become an air jet to move the tubular element 1 away from the spindle 13) while at the same time the pocket 18 captures the tubular element 1 by activating its suction. Finally, the pocket 18 of the insertion drum 16 radially moves relative to the insertion drum 16 from the expanded exchange position to the contracted rotation position to withdraw the tubular element 1 (held by suction inside the pocket 18) from the spindle 13.

[0054] Once the pocket 18 has removed the tubular element 1 from the spindle 13 in the transfer station S5, the rotation of the insertion drum 16 around the rotation axis 13 moves the pocket 18 into the insertion station S6 where the pocket 18 is standing still. When the pocket 18 is standing still in the insertion station S6, the same pocket 18 (which is in the contracted rotation position) radially moves relative to the insertion drum 16 from the contracted rotation position to the expanded exchange position to couple to the inserting body 45; in this way, the inserting body 45 enters the pocket 18 and then enters the tubular element 1 housed in the pocket 18. At the same time, the pushing element 46 pushes a filter 2 along the entire inserting body 45 until the filter 2 comes out from the narrower (smaller) output end of the inserting body 45 (as described above) and then arrange (permanently) by interference the filter 2 inside the tubular element 1. When the insertion of the filter 2 into the tubular element 1 is completed, the pocket 18 of the insertion drum 16 radially moves relative to the insertion drum 16 from the expanded exchange position to the contracted rotation position to withdraw the tubular element 1 from the inserting body 45.

[0055] Once the pocket 18 of the insert drum 16 has returned to the contracted rotational position, the rotation of the insert drum 16 around the rotation axis 13 moves the pocket 18 from the insertion station S6 to the transfer station S7 where the pocket 18 is standing still. When the pocket 18 is standing still in the transfer station S7, the same pocket 18 (which is in the contracted rotation position) radially moves relative to the insertion drum 16 from the contracted rotation position to the expanded exchange position; at this point the tubular element 1 is released from the pocket 18 of the insertion drum 16 to the holding head 23 of the transfer drum 21.

[0056] Subsequently, the transfer drum 21 releases the tubular element 1 to the output conveyor 20.

[0057] By way of example, the filters 2 can be formed by a cardboard sheet 4 folded on itself or they can be formed by acetate fibres enclosed in a paper strip folded in a tubular manner.

[0058] According to a further embodiment, the tubular element 1 is devoid of the filter 2, namely, no filter 2 is inserted inside the tubular element 1.

[0059] According to a preferred embodiment, below the feeding drum 27, the wrapping drum 11, the insertion drum 16, and the transfer drum 21 four corresponding containers 53 are arranged, which are intended to receive any scraps which, once identified as waste, are abandoned, and fall into the containers 53 due to gravity.

[0060] According to a further embodiment, the manufacturing machine 4 also comprises a filling drum (for example interposed between the insertion drum 16 and the output conveyor 20) where powdered tobacco or another type of smoking material is fed into the tubular element 1.

[0061] In the embodiment illustrated in the attached figures, the seats 7, the pockets 18 and 50, the holding heads 23 and 29 and the spindles 13 are moved along the respective paths P1-P5 by rotary conveyors (the drums 5, 11, 16 , 21, 27 and 48); according to a different embodiment, not illustrated, some or all of the rotary conveyors (the drums 5, 11, 16, 21, 27 and 48) are replaced by corresponding linear conveyors (and therefore the respective paths P1-P5 are no longer circular but linear).

[0062] In the embodiment described above, the tubular element 1 has a truncated cone shape (namely, with a progressively increasing cross-section moving away from the filter 2); according to a different embodiment not illustrated, the tubular element 1 has a cylindrical shape (namely, a constant cross-section along its entire extension). Obviously also in this embodiment, the filter 2 can be shaped differently or it can be absent.

[0063] In the embodiment illustrated in the attached figures, the tubular element 1 is intended for the manual production of a cigarette; according to a different embodiment, the tubular element 1 (obviously without the filter 2 and having a truncated cone or cylindrical shape) has a different final destination, for example it could form a straw for drinks (namely, a straw for sipping a drink). Obviously, in order to make a drinking straw it is necessary for the wrapping sheet 3 to be made of a sufficiently impermeable paper or of another material that is impermeable.

[0064] The embodiments described herein can be combined with one another without departing from the scope of the present invention.

[0065] The manufacturing machine 4 described above has numerous advantages.

[0066] In the first place, the manufacturing machine 4 described above allows to achieve high hourly productivity (the nominal hourly productivity of the manufacturing machine 4 is of the order of 200-300 tubular elements 1 per minute) while guaranteeing a high-quality standard (namely, guaranteeing the forming of tubular elements 1 having a perfect shape without wrinkles or more or less accentuated deformations). This result is obtained, among other things, due to a particularly gentle, but at the same time very effective and efficient treatment of the wrapping sheets 3, which are never excessively mechanically stressed and at the same time always have a known and given position.

[0067] Furthermore, the manufacturing machine 4 is particularly compact and allows an operator who is in near the manufacturing machine 4 to reach by hand, all the various parts of the manufacturing machine 4 without having to perform unnatural movements.

[0068] Finally, the manufacturing machine 4 is relatively simple and inexpensive to implement.LIST OF REFERENCE NUMBERS OF THE FIGURE

[0069] 1tubular element 2filter 3wrapping sheet 4manufacturing machine 5input drum 6rotation axis 7seat 8holding wall 9groove 10actuator 11wrapping drum 12rotation axis 13spindles 14countering body 15actuator 16insertion drum 17rotation axis 18pockets 19actuator 20output conveyor 21transfer drum 22rotation axis 23holding heads 24feeding system 25paper band 26cutting device 27feeding drum 28rotation axis 29pockets 30gluing device 31spraying head 32actuator 33track 34slide 35bracket 36folding device 37folding element 38folding element 39rotation axis 40actuator 41actuator 42arm 43arm 44inserting device 45inserting body 46pushing element 47actuator 48feeding drum 49rotation axis 50pockets 51feeding device 52feeding channel 53containers P1input path P2wrapping path P3insertion path P4output path P5transfer path P6feeding path S1feeding station S2gluing station S3folding station S4stabilizing station S5transfer station S6insertion station S7transfer station S8cutting station S9loading station

Examples

Embodiment Construction

[0012]Number 1 in Figure 1 indicates, as a whole, a partially empty tubular element having a truncated cone shape and provided at one (narrower) end with a filter 2. The tubular element 1 is intended for the manual production of a cigarette by being filled with tobacco through the open end.

[0013]The tubular element is formed by a wrapping sheet 3 having a trapezoid shape (illustrated extended in Figure 2) which is wrapped upon itself into a tube until one end overlaps the other end; in particular, a permanent vinyl-based glue is interposed between the two overlapping ends and keeps the two overlapping ends joined together, thus stabilizing the tube-like folding of the wrapping sheet 3.

[0014]Number 4 in Figures 3 and 4 indicates, as a whole, a manufacturing machine (only partially illustrated) for the production of the tubular elements 1 described above. The manufacturing machine 4 has an intermittent motion, namely, its conveyors cyclically alternate motion phases and stop phases.

[0...

Claims

1. A manufacturing machine (4) for the production of a tubular element (1), in particular for a smoking article; the manufacturing machine (4) comprises: an input conveyor (5), which moves at least one seat (7) along an input path (P1); a wrapping conveyor (11), which moves at least one spindle (13), having the shape of an inner cavity of the tubular element (1), along a wrapping path (P2); a feeding station (S1), where the seat (7) receives a wrapping sheet (3); and a folding station (S3), where the seat (7) releases the wrapping sheet (3) to the spindle (13) thus folding the wrapping sheet (3) around the spindle (13) in a "U"-shape; the manufacturing machine (4) is characterized in that it comprises a folding device (36), which is permanently arranged in the folding station (S3), is independent of and separate from the input conveyor (5) and from the wrapping conveyor (11) and is configured to fold the previously "U"-folded wrapping sheet (3) in a tubular manner and around the spindle (13) by overlapping two opposite edges of the wrapping sheet (3) one on top of the other.

2. The manufacturing machine (4) according to claim 1, wherein the folding device (36) comprises two folding elements (37, 38), which are arranged on opposite sides of the spindle (13) and are movable independently of one another relative to the spindle (13) so as to move between a waiting position, in which the folding elements (37, 38) are farther from the spindle (13), and a folding position, in which the folding elements (37, 38) are closer to the spindle (13).

3. The manufacturing machine (4) according to claim 2, wherein, after the wrapping sheet (3) has been folded around the spindle (13) in a "U" shape, a first folding element (37) moves from the waiting position to the folding position so as to fold a first edge of the "U"-folded wrapping sheet (3) against the spindle (13) and, subsequently, a second folding element (38) moves from the waiting position to the folding position so as to fold a second edge of the "U"-folded wrapping sheet (3) against the spindle (13) and on top of the first edge, which was previously folded by the first folding element (37), in order to complete the tubular wrapping of the wrapping sheet (3) around the spindle (13), thus forming the tubular element (1).

4. The manufacturing machine (4) according to claim 2 or 3, wherein the two folding elements (37, 38) are mounted to rotate around a same common rotation axis (39) in an independent manner from one another.

5. The manufacturing machine (4) according to claim 4 and comprising two different actuators (40 41), which transmit the motion to the folding elements (37, 38) by means of two respective arms (42, 43).

6. The manufacturing machine (4) according to one of the claims from 1 to 5, wherein the wrapping conveyor (11) comprises a countering body (14), which is coupled to the corresponding spindle (13), and an actuator (15) configured to move the countering body (14) between a rest position, in which the countering body (14) is far from the spindle (13) in order to allow the wrapping sheet (3) to be folded around the spindle (13) in a tubular manner in the folding station (S13), and a work position, in which the countering body (14) presses against the spindle (13) in the overlapping area of the two edges of the wrapping sheet (3) wound in a tubular manner.

7. The manufacturing machine (4) according to one of the claims from 1 to 6, wherein the seats (7) are mounted in a fixed position on the input conveyor (5) so as not to perform any movement relative to the input conveyor (5).

8. The manufacturing machine (4) according to claim 7, wherein the input conveyor (5) can both rotate around a rotation axis (6) and axially slide along the rotation axis (6).

9. The manufacturing machine (4) according to claim 8, wherein: the seat (7) has a holding wall (8), which is designed to hold the wrapping sheet (3) by means of suction and has, at the centre, a groove (9), which reproduces in negative the shape of the tubular element (1); and in the folding station (S3) a relative movement between the seat (7) and the spindle (13) is caused by axially moving the input conveyor (5) so that the spindle (13) pushes the wrapping sheet (3) into the groove (9) of the holding wall (8) to determine the "U"-shaped folding of the wrapping sheet (3) around the spindle (13) .

10. The manufacturing machine (4) according to one of the claims from 1 to 9 and comprising a gluing device (30), which is coupled to the input conveyor (5) and is configured to deposit glue along an edge of the wrapping sheet (3) carried by the seat (7).

11. The manufacturing machine (4) according to claim 10, wherein the gluing device (30) comprises a spraying head (31) configured to deposit glue and an actuator (32) configured to move the spraying head (31) while depositing the glue and along a straight gluing path, which is transverse to an input path (P1) generated by the input conveyor (5) to the seat (7).

12. The manufacturing machine (4) according to claim 11, wherein the actuator (32) comprises: a track (33) oriented parallel to the gluing path; a slide (34), which slides along track (33) and supports the spraying head (31); and a motor, which controls the position of the slide (34) along the track (33).

13. The manufacturing machine (4) according to claim 12, wherein the slide (34) supports the spraying head (31) by means of an "L"-shaped bracket (35).

14. The manufacturing machine (4) according to one of the claims from 1 to 13 and comprising: a cutting station (S8), where a cutting device (26) is arranged, which is configured to separate, by means of a transverse cut, the wrapping sheet (3) from a band (25) of wrapping material; and a feeding drum (27), which moves at least one holding head (29) designed to hold the wrapping sheet (3) along a feeding path (P6) developing between the cutting station (S8) and the feeding station (S1).

15. A manufacturing machine (4) according to claim 14, wherein the holding head (29) is mounted on the feeding drum (27) in a rotary manner to rotate relative to the feeding drum (27) around a rotation axis, which is parallel to a rotation axis (28) of the feeding drum (27).

16. The manufacturing machine (4) according to claim 15, wherein: the tubular element (1) has a truncated cone shape; the wrapping sheet (3) has a trapezoid shape; and the feeding drum (27) moves at least two different holding heads (29), which perform respective 180° rotations, which are different from one another, around the respective rotation axes between the cutting station (S8) and the feeding station (S1).

17. A manufacturing method for the production of a tubular element (1), in particular for a smoking article; the manufacturing method comprises the steps of: moving, by means of an input conveyor (5), at least one seat (7) along an input path (P1); moving, by means of a wrapping conveyor (11), at least one spindle (13), which has the shape of an inner cavity of the tubular element (1), along a wrapping path (P2); feeding, in a first feeding station (S1), a wrapping sheet (3) to the seat (7); and releasing, in a folding station (S3), the wrapping sheet (3) from the seat (7) to the spindle (13) by folding the wrapping sheet (3) around the spindle (13) in a "U"-shape; and folding the previously "U"-folded wrapping sheet (3) in a tubular manner and around the spindle (13) by overlapping two opposite edges of the wrapping sheet (3); the wrapping method is characterized in that the wrapping sheet (3) is folded in a tubular manner and around the spindle by a folding device (36), which is permanently arranged in the folding station (S3) and is independent of and separate from the input conveyor (5) and from the wrapping conveyor (11).

Images