WO2022029561A1

WO2022029561A1 - Method and machine for making a sub-unit of a smoking article

Info

Publication number: WO2022029561A1
Application number: PCT/IB2021/056800
Authority: WO
Inventors: Gabriele BENNI; Federico QUARELLI DI LESEGNO; Lorena D'ALFONSO; Marco Esposti; Ivan Eusepi; Roberto Polloni; Nicola Baldanza; Giuliano Gamberini
Original assignee: G.D S.P.A.
Priority date: 2020-08-07
Filing date: 2021-07-27
Publication date: 2022-02-10
Also published as: IT202000019585A1

Abstract

A method for making a sub-unit of a smoking article, comprising the steps of: preparing at least one rod-shaped segment (1) and a tubular body (2'a, 2''a, 2'''a, 2''''a), stably connected to each other and aligned along an axis of said sub-unit (100), the tubular body (2'a, 2''a, 2'''a, 2''''a) defining internally a containment chamber (4) and extending between a first end, connected to the segment (1), and a second end having an access opening (5) to the containment chamber (4); inserting a filler material into the containment chamber (4) of the tubular body (2'a, 2''a, 2'''a, 2''''a) through said access opening (5); closing at least partly said access opening (5) to prevent the escape of said filler material from the containment chamber (4); wherein said second end of the tubular body (2'a, 2''a, 2'''a, 2''''a) has a shape defining a succession of closing tabs (10) arranged one after another along a peripheral extension of said second end and alternated with corresponding recesses (20) and wherein said step of closing the access opening (5) comprises a step of folding said tabs (10) transversely to said axis to at least partly obstruct said access opening (5).

Description

DESCRIPTION

METHOD AND MACHINE FOR MAKING A SUB-UNIT OF A SMOKING ARTICLE

Technical field

This invention relates to a method and a machine for making a sub-unit suitable for the production of a smoking article, where “smoking article” in the context of this invention refers to articles that work by burning or heating tobacco, articles that generate aerosols other similar articles.

Further, the term “sub-unit” is used to mean a part of an end article (or “unit”) to be made, where such a part is made independently and separately and subsequently assembled with other components to obtain the end article.

Background art

Known at the present time are methods for making sub-units for smoking articles by cutting a double-length, empty sub-unit in half to obtain two empty sub-units which are then filled and closed at the free ends. A method of this kind is known from patent application WO2019/123296 in the name of the present Applicant.

It has been noticed that this production method can be further improved, in particular with regard to the efficacy and simplicity of making the closure, hence the quality and cost of the production process.

Aim of the invention

This invention therefore has for an aim to provide a method and a machine for making a sub-unit of a smoking article to achieve high production quality and, at the same time, high process economy.

The aim specified is substantially achieved by a method and a machine for making a sub-unit of a smoking article comprising the technical features set out in claims 1 and 14, respectively, and/or in one or more of the claims dependent thereon. According to the invention, the method comprises the following steps:

- preparing at least one rod-shaped segment and a tubular body, stably connected to each other and aligned along an axis of the subunit, where the tubular body internally defines a containment chamber and extends between a first end, connected to the segment, and a second end having an access opening to the containment chamber;

- inserting a filler into the containment chamber of the tubular body through the access opening;

- closing the access opening at least partly to prevent the escape of the filler material; wherein the second end of the tubular body has a shape defining a succession of closing tabs arranged one after another along a peripheral extension of the second end and alternated with corresponding recesses and wherein the step of closing the access opening comprises a step of folding the tabs transversely to the axis to at least partly obstruct the access opening.

In a preferred embodiment, each sub-unit is obtained by dividing a corresponding sub-unit of double length at a zone half way along it to obtain two identical or substantially identical sub-units.

In this situation, the step of preparing at least one rod-shaped segment and a tubular body is accomplished by preparing a pair of rod-shaped segments which are coaxial and axially spaced from each other and a tubular body of double length interposed between the segments to connect them. The tubular body of double length is then divided into two parts to define two tubular bodies of unit length having a first end that is fixed to a respective segment and the second end provided with tabs.

Advantageously, the tabs are formed during the step of separating since the tubular body of double length is separated along a non-planar half-way separation line which repeatedly and alternately intersects a midplane of the tubular body of double length, perpendicular to the longitudinal axis of the tubular body of double length.

In a first embodiment, the tubular body of double length is made of a rigid or semirigid material, preferably cardboard, and its ends are fixed to the respective rod-shaped segments, in particular by respective paper wrappers, where the tabs are made only on the rigid material. In other words, the wrappers are applied on lateral areas of the tubular body of double length, leaving uncovered a central part where the aforementioned separation line is made.

In a second embodiment, the tubular body of double length comprises an inner layer of rigid or semirigid material, specifically a tube, preferably of cardboard or other suitable material, and an outer layer of paper material defined by a single wrapper applied to the segments by rolling, where the tabs are made on both the inner and outer layers. In this embodiment, the entire portion of the tubular body which extends between the segments is of double thickness (inner layer and outer layer), including the central portion where the aforementioned separation line is made. The closing tabs are therefore made on both the inner layer and the outer layer.

In a third embodiment, the tubular body of double length is made from a single wrapper preferably made of paper, in particular of double width, applied in particular to the segments, and the tabs are therefore made exclusively on the wrapper. Preferably, the wrapper of double width is applied to the segments by rolling and itself defines the tubular body of double length after rolling.

In a variant of this third embodiment, there are two tubes placed inside the tubular body, each abutting a respective segment and being preferably equal in diameter to the respective segment. A cavity is formed between the two tubes centrally along the longitudinal direction, where the aforementioned separation line is made only on the tubular body (wrapper). In a variant embodiment, the wrapper is provided with creased or weakened zones (made by laser, for example) to facilitate subsequent folding of the wrapper, in particular to facilitate subsequent folding of the tabs. The wrapper may be obtained from a continuous web that is cut transversely to its longitudinal extension. In such a case, the step of preparing a connecting wrapper for joining the segments to each other is preceded by the following steps: feeding a continuous web which is cut transversely to obtain a plurality of wrappers; creasing or weakening (by laser, for example) at least some zones of the continuous web; transversely cutting the continuous web to obtain a plurality of wrappers (which can be folded easily at the creased or weakened zones).

Alternatively, the step of creasing or weakening might be performed on precut wrappers.

In the embodiments mentioned above, the tabs, before the step of closing (that is to say, at the time of separating) are substantially parallel with the longitudinal axis of extension of the sub-unit and of the tubular body.

In a first production solution, the tabs are made after a step of forming the tubular body of double length and/or of applying the tubular body of double length to the rod-shaped segments. This is accomplished in a step of rolling following the rolling of the wrapper/wrappers, in particular by a laser source. In a second production solution, the tabs are made before the step of forming the tubular body of double length and/or of applying the tubular body of double length to the rod-shaped segments, in particular by preforming (partially forming) the tabs by making a cutting profile interrupted in such a way as to make programmed yield connection zones, in particular which can be torn mechanically during the step of dividing the tubular body of double length into two parts. Preferably, the programmed yield connection zones are made at zones of ridges of the tabs and/or at bottom zones of the recesses. In effect, the circumferential shape of the separation line is wavy or zig-zagged so that the tabs are alternated with recesses such that the tabs of a first part of the tubular body of double length are formed by the recesses of the second part of the tubular body of double length. In other words, the contoured profiles of the open ends of the two parts into which the tubular body of double length is divided are shaped to match each other. This eliminates all waste offcuts.

Preferably, also, the tabs have a matching, reversed shape relative to the recesses.

The step of closing the tabs, which comprises bending the tabs transversely to the longitudinal axis of the sub-unit, is accomplished by rolling the subunit of unit length alongside a fixed folding side wall, in particular a fixed wall with a convergent profile for gradually folding the tabs in a transverse direction. Closing by rolling can be carried out while keeping the sub-unit oriented with its longitudinal axis horizontal.

In an alternative embodiment, the tabs can be closed by axial punching, in particular while keeping the sub-unit disposed in a vertical position with the open end facing up. This axial punching can be carried out in two steps by a first punch and a second punch having different folding profiles, in particular a partial folding profile and a finishing profile, respectively.

A machine for making a sub-unit of a smoking article according to the invention comprises:

- means for feeding groups of segments, wherein each group of segments comprises at least one pair of rod-shaped segments which are coaxial and axially spaced from each other;

- an applicator device configured to apply at least one wrapper to each group of segments;

- a rolling device configured for rolling each wrapper around the respective group of segments to obtain an empty sub-unit of double length having a tubular body of double length stably connected to the pair of segments;

- a separating device located downstream of the rolling device and configured to separate the empty sub-unit of double length into two sub-units of unit length along a separation line made on the tubular body of double length, each sub-unit having a rod-shaped segment to which is fixed a tubular body defining a containment chamber and having an end having an access opening; - filling means, configured to insert a filler material into said containment chamber of the tubular body through the access opening;

- closing means, located downstream of the filling means and configured to close said access opening of the tubular body to prevent the filler material from escaping.

The machine also comprises cutting means configured for making an incision on the tubular body of double length and/or on the at least one wrapper according to a non-rectilinear or non-planar cutting line in such a way that, following separation by means of the separating device, each subunit of unit length has at one end a shape defining a succession of closing tabs positioned in succession along a peripheral extension of that end and alternated with corresponding recesses. The closing means are configured for folding the tabs transversely to an axis of extension of the sub-unit of unit length for at least partly closing the access opening.

Preferably, the machine is at least partly configured for transversely feeding the groups of segments and the sub-unit by means of a suction drum, in particular from the feed means to the separating device and preferably also comprising turnaround drums configured (where necessary) to turn the subunits of unit length around vertically in order to be able to fill them.

In an embodiment, the cutting means are located downstream of the rolling device to make a continuous incision on the tubular body of double length in such a way as to make a complete detachment line extending along a preferably closed profile.

In a different embodiment, the cutting means are located at or upstream of the wrapper applicator device and are configured to make an interrupted cutting profile on the wrappers, in particular to make an interrupted cutting profile on a continuous web that will be cut into separate wrappers. The interrupted incision is made by creating connection zones with programmed yield, in particular which can be torn mechanically during a step of dividing the tubular body of double length into two parts by means of the separation device.

In a variant embodiment, the machine comprises a device for processing a continuous web by cutting it into a plurality of wrappers and which is configured for creasing or weakening (for example, by laser) on at least some zones of the continuous web to obtain wrappers that are easy to fold at the creased or weakened zones.

In a variant embodiment, the machine might comprise a device for processing the wrappers by creasing or weakening them (for example, by laser) on at least some zones of each wrapper to obtain wrappers that are easy to fold at the creased or weakened zones.

Brief description of the drawings

Further features and advantages of this invention are more apparent in the indicative, non-limiting description below, with reference to a preferred, but non-exclusive embodiment of a method and a machine for making a subunit of a smoking article, as illustrated in the accompanying drawings in which:

- Figures 1A-1 F schematically represent a sequence of operating steps performed by a first embodiment of the method according to the invention;

- Figures 2A-2F schematically represent a sequence of operating steps performed by a second embodiment of the method according to the invention;

- Figures 3A-3F schematically represent a sequence of operating steps performed by a third embodiment of the method according to the invention;

- Figures 4A-4F schematically represent a sequence of operating steps performed by a fourth embodiment of the method according to the invention;

- Figures 5A and 5B illustrate a portion of a sub-unit made according to the invention in two different steps of the method; - Figures 6-8 represent variant embodiments suitable for making the portion of Figures 5A and 5B;

- Figures 9 and 10 represent further variant embodiments suitable for making the portion of Figures 5A and 5B;

- Figures 9A and 10A are enlarged views of details from Figures 9 and 10;

- Figures 1 1 and 12 schematically represent two constructional solutions of the machine according to the invention;

- Figure 13 schematically represents a first solution of a closing unit used in the machine according to the invention;

- Figure 14 is an enlarged view of the closing unit of Figure 13;

- Figure 15 schematically represents a second solution of a closing unit used in the machine according to the invention.

Detailed description of preferred embodiments of the invention

Figures 1 A-1 F represent a first embodiment of a method according to the invention, used for making a sequence of sub-units 100 of smoking articles (Figure 1 F). More specifically, the method according to Figures 1 A-1 F relates to the production of a pair of identical sub-units 100 but since the method is repeatable for an indefinite number of times, it can be performed automatically and sequentially to make a succession of pairs of sub-units 100 using an automatic machine.

In the context of this invention, the term “smoking article” is used generically to mean an article suitable for smoking or for generating an aerosol, hence an article which uses tobacco based products or technology for producing aerosols.

The method works by making an empty sub-unit of double length (Figure 1 C) which is then cut in half to obtain two empty sub-units of unit length, which are then filled and closed.

More in detail, the method comprises a first step (Figure 1 A) in which a tubular body 2 of double length is interposed between two rod-shaped segments 1 of unit length (that is to say, the same length as a finished subunit 100) which are axially spaced from each other so that the ends of the tubular body 2 abut up against the segments 1 and can connect the segments 1 .

In variant embodiments, the tubular body 2 of double length may be interposed between the segments 1 but with its ends spaced from the segments 1 ; in this case, there is a cavity between each segment 1 and the tubular body 2.

The tubular body 2 is defined by a tube 2’ made of rigid or semirigid material having greater bending strength than a plain tube made from a paper web, for example, thanks to its greater thickness compared to a thin paper web. Preferably, the tube 2’ is made from a cellulose based product, in particular cardboard or PLA or other rigid or semirigid material suitable for the purpose.

The segments 1 may be of a filtering type or of a type suitable for generating an aerosol or smoke or of a heating type. Whatever the case, the segments 1 are of a type suitable for at least partly closing the corresponding ends of the tube 2’ they are applied to, hence they are full or substantially full in transverse cross section.

In the next step (Figure 1 B), a pair of connecting wrappers 3, each used to connect a segment 1 with the respective end of the tube 2’, is provided. These wrappers are made preferably of paper material.

Each wrapper 3 is applied so it connects the respective segment 1 to the corresponding end of the tube 2’, in particular by gluing and preferably by means of a rolling process. Gluing preferably involves the entire surface of the wrapper 3.

Further, in the embodiment illustrated, each wrapper 3 covers the whole of the respective segment 1 and partly covers the tube 2’, in particular in such a way that a central portion of the tube 2’ is not covered by the wrappers 3 and is therefore exposed.

In variant embodiments, each wrapper 3 covers only part of the respective segment 1 and/or a specific, non-uniform glue pattern is used.

Next, the tube 2’ is separated into two parts to obtain two tubes 2’a, 2’b of unit length, each having a first end which is fixed to a respective segment 1 by a respective wrapper 3 and a second end which is open. In particular, each tube 2’a, 2’b defines internally a containment chamber 4 and extends between a first end which is abutted against the respective segment 1 and a second end which has an access opening 5 giving access to the containment chamber 4. Preferably, the containment chamber 4 extends for the full length of the tube 2’a, 2’b of unit length.

In the embodiment of Figures 1 A-1 F, the tube 2’ of double length is divided by a cutting process (Figure 1 C) carried out at the same time as or after the step of applying the segments 1 by means of the wrapper 3, and a subsequent step of spacing the two parts thus obtained, in particular spacing them apart axially (Figure 1 D). In a preferred embodiment, cutting is performed by laser by rotating the tube 2’ about its longitudinal axis (for example, by rolling) and/or by rotating a laser source (not illustrated) around the tube 2’.

Advantageously, the tube 2’ is cut along a non-planar circumferential line in such a way that the second end of each tube 2’a, 2’b has a shape defining a succession of closing tabs 10 arranged one after another along a peripheral extension of the second end, that is to say, angularly distributed around the longitudinal axis of the tube 2’, and alternated with corresponding recesses 20.

In other words, the cut is made on the central part of the tube 2’ and intersects a transverse plane of symmetry of the tube 2’ a plurality of times. This structure, according to a possible embodiment of it, is illustrated in detail in Figure 5A. In particular, the tabs 10 formed by cutting extend substantially parallel with the longitudinal axis of the tube 2’ and themselves define a part of the outer cylindrical surface of the tube 2’, and are alternated with respective recesses 20.

In an advantageous embodiment, the tabs 10 are shaped to match the recesses 20. That way, the same tabs can be obtained on both of the tubes 2’a, 2’b of unit length by a single cutting operation without producing waste offcuts.

In a different embodiment, the tabs 10 of one tube 2’a are shaped to match the recesses of the other tube 2’b. In this case, too, the tube 2’ of double length is separated into two parts provided with the tabs 10 without producing waste offcuts.

Figures 6-8 illustrate different embodiments of the tabs 10, falling within the scope of the inventive concept of this invention.

After separating the tube 2’ into two parts, the method comprises a step of filling (Figure 1 E) in which a filler material is placed inside each containment chamber 4. The filler material may be incoherent material such as powder, fibres or granules, for example, or it may be one or more discrete elements, such as capsules, for example (as in the embodiment illustrated).

The containment chamber 4 is then closed by bending the tabs 10 over to at least partly close the access opening 5 in order to trap the contents in the containment chamber 4. In particular, the tabs 10 are bent over so they adopt an orientation that is transverse, preferably perpendicular, to the longitudinal axis of the tube 2’a, 2’b (Figure 1 F, Figure 5B). In variant embodiments, the tabs 10 are bent over so they adopt an orientation that is transverse, preferably concave, to the longitudinal axis of the tube 2’a, 2’b. In the solution shown in Figure 5B, the tabs 10 close the corresponding end of the sub-unit 100 completely. Preferably, in the closed configuration, the tabs 10 can be perforated to allow the passage of a work tool (a needle, for example) during use of the sub-unit 100. Alternatively, in the closed configuration, the tabs 10 leave a hole in the middle of the end open to allow the work tool to be inserted.

Thanks to the distribution of the tabs 10 alternated with the recesses 20, folding leads to optimum closing without additional fold lines between the tabs and without unwanted overlapping that might obstruct closing and prevent the tabs from remaining in the folded position. In the embodiment of Figures 1 A-1 F, the tabs are made on the tube 2’ and thus have the same thickness as the tube 2’. Preferably, the tabs are of the single-layer type, where the layer is defined by the thickness of the tube 2’. The embodiment of Figures 2A-2F differs from the previous one in that the tubular body 2 is made of paper material and defined by a single paper wrapper 2” of double length applied to the outside of the segments 1 , in particular by rolling. The double wrapper 2”, rectangular in shape, has ends that are applied to the outside of the segments 1 , for example, to cover a portion of the cylindrical outside surface of the segments 1 (or alternatively, the whole of the cylindrical outside surface of the segments 1 ).

Furthermore, in the embodiment of Figures 2A-2F, the tubular body 2 accommodates a pair of coaxial tubes 6, axially spaced from each other and preferably abutted up against the respective segment 1 . Like the tube 2’ of Figures 1 A-1 F, the tubes 6 are made of a rigid or semirigid material, such as, for example, cardboard, PLA or other material suitable for the purpose. In a sequence of steps of the related production process, there is a first step (Figure 2A) of preparing two rod-shaped segments 1 coaxial with and axially spaced from each other and each abutting up against a corresponding tube 6 and preferably not connected to the tube 6. The tubes 6, on the other hand, are axially spaced from each other.

Next (Figure 2B), there is a step of preparing a connecting wrapper 2” used to connect the segments 1 and the tubes 6 to each other to form a single tubular body 2 wrapped (at least partly) around the outside of the segments 1 and (the whole of) the tubes 6, thereby also forming a central tubular portion interposed between the two tubes 6.

The wrapper 2” is applied by gluing and preferably by a rolling process. Gluing preferably involves the entire surface of the wrapper in contact with the segments 1 and the tubes 6, with the exception of the aforementioned central tubular portion interposed between the two tubes 6.

Next, the tubular body 2” is separated into two parts to obtain two tubes 2”a, 2”b of unit length, each having a first end which is applied to the outside of a respective segment 1 and a second end which is open, and each also provided with a tube 6 internally at a central position. Each tube 2”a, 2”b defines internally a containment chamber 4, which extends at least partly inside the tube 6, and extends between a first end, applied to the segment 1 , and a second end having an access opening 5 giving access to the containment chamber 4. The tube 6 is smaller in axial length than the corresponding tube 2”a, 2”b so that an end portion of each tube 2”a, 2”b protrudes axially relative to the tube 6.

In the embodiment of Figures 2A-2F, the tubular body 2 is divided by a cutting process (Figure 2C) carried out at the same time as or after the step of rolling the double wrapper 2” onto the segments 1 , and a step of spacing the two parts thus obtained, in particular spacing them apart axially (Figure 2D). In a preferred embodiment, cutting is performed by laser by rotating the tubular body 2 about its longitudinal axis (for example, by rolling) and/or by rotating a laser source (not illustrated) around the tubular body 2.

Further, the cut is made on the central part of the tubular body 2, that is to say, on the aforementioned central portion that is interposed between the tubes 6. In other words, the cut is made on a zone of the double sub-unit with a single thickness defined only by the tubular body 2 of paper.

The tubular body 2 is cut along a non-planar circumferential line in the same way as described above with reference to the embodiment of Figures 1 A- 1 F. All the features described with reference to the shape of the cutting line, tabs and recesses apply here, too.

After separating the tubular body 2 into two parts, the method comprises a step of filling (Figure 2E) in which a filler material is placed inside each containment chamber 4. The filler material may be incoherent material such as powder, fibres or granules, for example, or it may be one or more discrete elements, such as capsules, for example (as in the embodiment illustrated). The containment chamber 4 is then closed by bending the tabs 10 over to at least partly close the access opening 5 in order to trap the contents in the containment chamber. In particular, the tabs 10 are bent over so they adopt an orientation that is transverse, preferably perpendicular, to the longitudinal axis of the tubular body 2 (Figure 2F). Alternatively, the tabs 10 may also be bent inwards in such a way as to apply a blocking action on the contents of the containment chamber 4.

Preferably, in the embodiment of Figures 2A-2F, the wrapper 2” is provided with creased or weakened zones (made by laser, for example) to facilitate subsequent folding of the wrapper 2”, in particular to facilitate subsequent folding of the tabs 10.

Preferably, the wrapper 2” is obtained from a continuous web that is cut transversely to its longitudinal extension. In that case, before the step of preparing a connecting wrapper 2” used to connect the segments 1 and the tubes 6 to each other, the method illustrated in Figures 2A-2F comprises the following steps: feeding a continuous web which is cut transversely to obtain a plurality of wrappers 2”; creasing or weakening (by laser, for example) at least some zones of the continuous web; transversely cutting the continuous web to obtain a plurality of wrappers 2” (which can be folded easily at the creased or weakened zones).

In a variant embodiment, the step of creasing or weakening might be performed on pre-cut wrappers 2”.

It is understood that using a wrapper 2” provided with creased or weakened zones to facilitate subsequent folding of the wrapper 2”, in particular to facilitate subsequent folding of the tabs 10, is possible in any of the embodiments illustrated.

Figures 3A-3F illustrate a further embodiment of the method according to the invention, differing from the embodiment of Figures 2A-2F in that it uses a single central tube 7 on which a single connecting wrapper 2” is wrapped. Thus, in this case, the step of cutting into parts (Figure 3C) is performed on a portion with double thickness, defined by the superposition between the thickness of the tube 7 and the thickness of the connecting wrapper 2”’ to obtain two tubes 7 of unit length and two corresponding connecting wrappers 2”’a, 2”’b. It follows that the tabs 10 are also defined by zones with double thickness. Gluing between the connecting wrapper 2”’ and the central tube 7 may be uniform over the entire mutually superposed surface or, in a possible embodiment, the superposed zone where the tabs 10 are formed might be excluded.

Figures 4A-4F illustrate a further embodiment of the method according to the invention, differing from the embodiment of Figures 2A-2F in that no internal tubes 6 are used. Consequently, the tubular body 2 is obtained solely by rolling a single connecting paper wrapper 2”” supported at the ends of it by the segments 1 . In this case, therefore, the step of cutting into two parts (Figure 4C) is performed on a portion with single thickness, defined by the connecting wrapper 2””, in particular in the same way as described with reference to the preceding embodiments.

It follows that the tabs 10 are also defined by zones with single thickness.

In all the embodiments described above with reference to the accompanying drawings, the step of cutting the tubular body 2 of double length is performed after the step of forming the tubular body 2 of double length and/or applying the tubular body 2 of double length to the segments 1 . In detail, this cutting operation must be considered as the operation by which the tabs 10 are formed, in particular by laser cutting.

Looking in more detail, as described above, the cut can be made while rolling the connecting wrapper or wrappers, using the rotational movement of the entire sub-unit to perform rolling (for example, with a stationary laser source) or after rolling, hence during a specific operating step. In the second situation, a laser source that moves around the double sub-unit might also be used.

In a variant embodiment, however, the cut is made before the step of forming the tubular body 2 of double length and/or applying the tubular body 2 of double length to the segments 1 .

In this variant, the tubular body 2 is cut partially or almost completely so that the two parts of the tubular body 2 are not separated completely. In particular, cutting is performed in such a way that some zones (“bridges”) continue to connect the two parts to be separated, for example, by means of a broken cutting line.

The partial cut is carried out on the rigid tube and/or on the connecting wrappers before rolling so that rolling can be performed correctly with the rigid tube and/or the connecting wrappers, respectively, in the double configuration having cut zones but still in a single piece.

The aforementioned connecting zones, labelled T, are visible in Figures 9 and 10 and in the respective enlarged views of Figures 9A and 10A and can advantageously be obtained in the zones of ridges and/or the bottom zones of the tabs 10.

The connecting zones T can be torn by moving the two parts of the tubular body 2 of double length away from each other during the aforementioned step of separating (for example, by means of a retracting drum provided with suction seats or other suitable movable gripping units).

Figures 11 -15 schematically illustrate possible embodiments of a machine (or parts of it) configured to implement a method according to what is described in the foregoing.

In particular, Figures 1 1 and 12, show two embodiments of a schematic layout for the machine 200. The machine 200 is preferably configured to transversely feed individual components (segments) 1 10 of the sub-units 100 by means of drums and comprises a transfer drum 210 for feeding the individual components 1 10 which have already been assembled (axially abutted end to end) in groups towards a zone for receiving a connecting wrapper 120. Coupled to the transfer drum 210 is a feed device 220 that feeds wrappers of substantially known type and that uses a supporting drum 221 that is tangent to the transfer drum 210 and a cutting drum 222 that acts in conjunction with the supporting drum 221 to cut a succession of wrappers transversely from a continuous web 201 .

The wrappers 120 cut off are applied to the respective groups of components 1 10, for example, in flag-like fashion, and then rolled in order to wrap it all the way round the group of components, in particular by means of a rolling device comprising a rolling drum 230 and a respective rolling bed 240.

The wrapper feed device 220 may be configured to deliver single wrappers 120 of double length (as in the embodiment of Figures 2-4) or a pair of juxtaposed wrappers (as in the embodiment of Figure 1 ). In the latter embodiment, the two juxtaposed wrappers may be cut from two webs running parallel to each other, obtained, for example, by longitudinally cutting a single continuous web.

In the embodiment of Figure 1 1 , configured to implement the method illustrated in Figures 1 -4, there is a cutting unit 250, preferably of a laser type, located downstream of the rolling drum 230 and configured to make the aforementioned circumferential cutting line. The cutting unit 250 is configured to make a circumferential cutting line by rotating the sub-unit of double length, obtained by rolling the wrapper (or wrappers) around the respective group of components 1 10, and the cutting unit 250 itself relative to each other. In the embodiment illustrated, the cutting unit 250 is stationary and works in conjunction with a conveying drum 260 while each sub-unit of double length is made to rotate in the zone of the cutting unit 250, for example by means of a suitable rolling bed 270.

Next, the two sub-units obtained by cutting the sub-unit of double length are separated by axial retraction, for example, by means of a retracting drum (not illustrated), and sent on to operating stations (for filling and closing) downstream.

In the embodiment of Figure 12, configured to implement a method alternative to that illustrated in Figures 1 -4, no cutting is carried out on the sub-units of double length but a partial cut is made on the continuous web 200 before, or at the same time as, it is divided into wrappers. This partial cut can be made by providing a cutting unit 280 upstream of, or at, the wrapper feed device 220 and allows the wrappers to have programmed yield lines which do not affect the rollability of the wrappers. Again, the sub-units of double length thus obtained are separable by axial retraction, in particular, by means of a retracting drum (not illustrated) located downstream of the rolling drum 230.

In an embodiment, the machine may comprise a device for processing the continuous web 201 by creasing or weakening it (for example, by laser) on at least some zones of the continuous web 201 in order to obtain wrappers that are easy to fold at the creased or weakened zones. Alternatively, the machine might comprise a device for processing the wrappers by creasing or weakening them (for example, by laser) on at least some zones of each wrapper to obtain wrappers that are easy to fold at the creased or weakened zones.

Figures 13 and 14 schematically illustrate a first embodiment of a closing unit 300 which is usable in the machine 200 and, in particular, located downstream of the zone where the sub-unit of double length is separated into sub-units 100 of unit length. The closing unit 300 receives the sub-units of unit length 100 from a sequence of drums shown in Figures 13 and 14 (inset 310) and rotates the sub-units 100 so their longitudinal axes are oriented vertically when they reach a horizontal axis conveyor 320 which is operated on by filling elements 330 and closing elements 340 after them. The filling elements 330 are configured to deliver a predetermined filler material (or content), for example, a capsule, into the containment chamber 4. The closing elements 340, on the other hand, are configured to shape the open end of each sub-unit 100 by folding the tabs 10, in particular by a punch-like action. Looking in more detail, the closing elements 340 are divided into a first group 341 of closing elements (punches) which partially fold the tabs 10 so their orientation is inclined, and a second group 342 of closing elements (punches) which complete the folding process (perpendicular or concave bending) of the tabs 10 to finish the closure.

Alternatively, the filling elements 330 and the closing elements 340 might operate while the sub-units 100 are disposed with their longitudinal axes oriented horizontally (or inclined at a different angle). In a variant embodiment, illustrated in Figure 15, the closing unit 300 comprises a fixed wall 350 converging in the direction of movement of the sub-units 100 while the sub-units advance transversely according to a rolling movement. The convergent shape of the fixed wall 350, having a helical profile, for example, gradually folds the tabs 10 until they reach their final position, where they are perpendicular and close the containment chamber 4. In this embodiment, the sub-units 100 may be disposed with their longitudinal axes oriented horizontally.

In a further variant embodiment (not illustrated), the closing unit comprises a plurality of folding fingers acting radially on the tabs, preferably by combined motion. This is preferably followed by the punching action which finishes the closure in the same way as in the embodiment of Figures 13 and 14 (second group 342 of closing elements).

The present invention achieves the preset aims, overcoming the disadvantages of the prior art.

In effect, the invention allows easy and effective closure using the tabs to create a closed configuration without overlaps and folding zones that would negatively affect the closure or the shape stability of the sub-unit as a whole. Moreover, the possibility of working without producing waste offcuts optimizes the process economy and the cleanness of the working environment.

Claims

1. A method for making a sub-unit of a smoking article, comprising the steps of:

- preparing at least one rod-shaped segment (1 ) and a tubular body (2’a, 2”a, 2”’a, 2””a), stably connected to each other and aligned along an axis of said sub-unit (100), the tubular body (2’a, 2”a, 2”’a, 2””a) defining internally a containment chamber (4) and extending between a first end, connected to the segment (1 ), and a second end having an access opening (5) to the containment chamber (4);

- inserting a filler material into the containment chamber (4) of the tubular body (2’a, 2”a, 2”’a, 2””a) through said access opening (5);

- closing at least partly said access opening (5) to prevent the escape of said filler material from the containment chamber (4);

- wherein said second end of the tubular body (2’a, 2”a, 2”’a, 2””a) has a shape defining a succession of closing tabs (10) arranged one after another along a peripheral extension of said second end and alternated with corresponding recesses (20) and wherein said step of closing the access opening (5) comprises a step of folding said tabs (10) transversely to said axis to at least partly obstruct said access opening (5).

2. The method according to claim 1 , wherein said tabs (10), before the closing step, extend substantially parallel to said axis.

3. The method according to claim 1 , wherein the step of preparing at least one rod-shaped segment (1 ) and a tubular body (2’a, 2”a, 2”’a, 2””a) is carried out by preparing a pair of rod-shaped segments (1 ) axially spaced from each other and a tubular body (2) of double length positioned for connecting between said segments (1 ), and it is followed by a step of dividing the tubular body (2) of double length into two parts forming two tubular bodies (2’a, 2’b; 2”a, 2”b; 2”’a, 2”’b; 2””a, 2””b) of unit length having a first end fixed to a respective segment (1 ) and the second end equipped with said tabs (10).

4. The method according to any one of the preceding claims, wherein said tabs (10) are made after a step of forming the tubular body (2) with a double length and/or application of the tubular body (2) with a double length to said at least one rod-shaped segment (1 ).

5. The method according to any one of claims 1 to 3, wherein said tabs (10) are made before forming the tubular body (2) with a double length and/or an application of the tubular body (2) of double length to said at least one rod-shaped segment (1 ).

6. The method according to claim 5, wherein said tabs (1 ) are formed by making a cutting profile interrupted in such a way as to make connection zones (T) with programmed yield, in particular which can be torn mechanically during said step of dividing the tubular body (2) with a double length into two parts, preferably said connection zones (T) with programmed yield being made at zones of ridges of said tabs (10) and/or bottom zones of said recesses (20).

7. The method according to any one of the preceding claims, wherein said tabs (1 ) are made by laser cutting.

8. The method according to any one of claims 3 to 7, wherein said tubular body (2) with a double length prepared for connecting between said rodshaped segments (1 ) is made of rigid material, preferably cardboard, and has relative ends fixed to respective rod-shaped segments (1 ), in particular using respective paper wrappers (3), and wherein said tabs (10) are made exclusively on said rigid material.

9. The method according to any one of claims 3 to 7, wherein said tubular body (2) of double length positioned for connecting between said rodshaped segments (1 ) is made using an inner layer (7) made of rigid material, preferably cardboard, and an outer layer (2”’) made of paper material and defined by a single paper wrapper (2”’) applied to said segments (1 ) in particular by rolling, and wherein said tabs (10) are made on both said inner and outer layers (7, 2”’).

10. The method according to any one of claims 3 to 7, wherein said tubular body (2) of double length positioned for connecting between the rod-shaped segments (1 ) is made from a single wrapper (3) preferably made of paper, in particular of double width, applied to said segments (1 ) in particular by rolling, and wherein said tabs (10) are made exclusively on said wrapper (3).

1 1 . The method according to claim 10, wherein said step of preparing at least one rod-shaped segment (1 ) and a tubular body (2’a, 2”a, 2”’a, 2””a) is carried out by preparing a pair of rod-shaped segments (1 ) axially spaced from each other and a pair of tubes (6) positioned between said segments (1 ) and each abutting a respective one of said segments (1 ) in such a way that said tubes (6) are axially spaced from each other, wherein said tubular body (2) of double length positioned for connecting between said segments (1 ) also wraps around said tubes (6) and wherein said tabs (10) are made exclusively on said wrapper (3) in central zone interposed between said tubes (6).

12. The method according to any one of the preceding claims, wherein said tabs (10) are shaped to match, and overturned, relative to said recesses (20).

13. The method according to any one of the preceding claims, wherein said closing step is performed by rolling the sub-unit (100) of unit length alongside a fixed folding side wall (350), in particular a fixed wall with a convergent profile for gradually folding the tabs (10) in a transversal direction, preferably said closing by rolling being achieved by keeping the sub-unit (100) oriented with its longitudinal axis horizontal.

14. A machine for making a sub-unit (100) of a smoking article, comprising:

- means (210) for feeding groups of segments (1 10), wherein each group of segments (1 10) comprises at least one pair of rod-shaped segments (1 ) which are coaxial and axially spaced from each other;

- an applicator device (220) configured to apply at least one wrapper (3) to each of said group of segments (110);

- a rolling device (230, 240) configured for rolling said at least one wrapper (3) around said group of segments (110) to obtain an empty sub-unit of double length having a tubular body (2) of double length stably connected to said pair of segments (1 );

- a separating device located downstream of the rolling device (230, 240) and configured to separate said empty sub-unit of double length into two sub-units (100) of unit length along a separation line made on said tubular body (2) of double length, each sub-unit (100) having a rod-shaped segment (1 ) to which is fixed a tubular body (2’a, 2”a, 2”’a, 2””a) defining a containment chamber (4) and having an end having an access opening (5);

- filling means (330), configured to insert a filler material into said containment chamber (4) of the tubular body (2’a, 2”a, 2”’a, 2””a) through the access opening (5);

- closing means (340; 350), located downstream of the filling means (330) and configured to close said access opening (5) of the tubular body (2’a, 2”a, 2”’a, 2””a) to prevent the filler material from escaping; wherein said machine (200) also comprises cutting means (250; 280) configured for making an incision on said tubular body (2) of double length and/or on said at least one wrapper (3) according to a non-rectilinear or non- planar cutting line in such a way that, following said separation by means of said separating device, each sub-unit (100) of unit length has at one end a shape defining a succession of closing tabs (10) positioned in succession along a peripheral extension of said end and alternated with corresponding recesses (20), said closing means (340, 350) being configured for folding said tabs (100) transversely to an axis of extension of said sub-unit (100) of unit length for closing at least partly said access opening (5).

15. The machine according to claim 14, wherein said cutting means (250; 280) are located downstream of said rolling device (230, 240) to make a continuous incision on said tubular body (2) of double length in such a way as to make a complete detachment line extending along a preferably closed profile.

16. The machine according to claim 15, wherein said cutting means (250, 280) are positioned at or upstream of the applicator device (220) and configured to form an interrupted cutting profile on said wrappers (3) or on a continuous web (201 ) designed to be separated into said wrappers (3), in particular said interrupted cut being made by making connection zones (T) with programmed yield, in particular which can be torn mechanically during a step of separating the tubular body (2) of double length into two parts using said separating device.

17. A sub-unit (100) of a smoking article, comprising at least one rodshaped segment (1 ) and a tubular body (2’a, 2”a, 2”’a, 2””a), stably connected to each other and aligned along an axis of said sub-unit (100), said tubular body (2’a, 2”a, 2”’a, 2””a) defining internally a containment chamber (4) containing a filler material and extending between a first end, connected to said segment (1 ), and a second end opposite the first end; and wherein said second end of the tubular body (2’a, 2”a, 2”’a, 2””a) has a shape defining a succession of closing tabs (10) arranged one after another along a peripheral extension of said second end and alternated with corresponding recesses (20), said tabs (10) being folded transversely to said axis to at least partly close said access opening (5) preventing the escape of the filler material.