APPARATUS AND METHOD FOR MAKING SEMIFINISHED PRODUCTS INTENDED TO FORM PART OF SMOKERS' ARTICLES

Description

Technical field

[0001] This invention relates to an apparatus and a method for making semifinished products intended to form part of smokers' articles.

Background art

[0002] In the context of cigarettes or, more in general, smokers' articles such as cigarettes, cigars or the like, tubular elements are inserted into the cigarette to act on the structure of the cigarette for spacing or strengthening purposes: for example to guarantee its roundness.

[0003] In this context, spiral wrapping machines are known, for example from patent documents WO2004/106017A1, CA793059A, GB1083088A, GB1083089A and US3349777A, which are used to form tubular rods which are then cut into portions to form the tubular elements.

[0004] This technology, however, raises several issues for which the prior art solutions provide limited responses.

[0005] One issue is that of productivity, that is to say, the need to have a machine which is capable of producing as output a large number of semifinished products per unit time.

[0006] Another need is that to make semifinished products of high quality and precision.

[0007] Another issue is connected with the ease with which the user can operate the machine.

Disclosure of the invention

[0008] This invention has for an aim to provide an apparatus and a method for making semifinished products intended (suitable) to form part of smokers' articles to overcome the abovementioned drawbacks of the prior art. It is observed that said semifinished products form (are) part of smokers' articles.

[0009] More specifically, one aim of this invention is to provide an apparatus and a method for making semifinished products intended (suitable) to form part of smokers' articles, with a particularly high productivity level.

[0010] A further aim of this invention is to provide an apparatus and a method for making semifinished products intended (suitable) to form part of smokers' articles, with high precision.

[0011] A further aim of this invention is to provide an apparatus and a method for making semifinished products intended (suitable) to form part of smokers' articles, to simplify the user's work.

[0012] These aims are fully achieved by the apparatus and method according to the invention as characterized in the appended claims.

[0013] More specifically, the invention relates to an apparatus for making semifinished products intended to form part of smokers' articles such as, for example, cigarettes, cigars or the like.

[0014] The apparatus comprises a mandrel which is elongate along a longitudinal axis. Preferably, the mandrel is stationary, that is to say, it is a part of the apparatus which is not in motion.

[0015] The apparatus comprises at least one inner strip and one outer strip; the inner strip is wrapped helically around the mandrel and the outer strip is wrapped helically around the inner strip in such a way that an inside face of the outer strip is in contact with an outside face of the inner strip. In an example embodiment not illustrated, there might be more than two strips wrapped around the mandrel (to increase its thickness or stiffen it), that is, the apparatus might comprise one or more further strips in addition to the inner strip and outer strip mentioned above.

[0016] It should be noted that these strips may be made of any material suitable to be joined permanently to a surface, for example by gluing or pressure sealing. For example, the strips might be made of materials such as paper, plastic or metal (for example, aluminium) or of multilayer, composite materials (for example, aluminium on one side and paper on the other). In an example embodiment, the different strips are made of the same material; they might, however, also be made of different materials. For simplicity, this description hereinafter refers to the strips as being made of paper, so the inner strip and the outer strip are in some cases referred to using the expressions "inner paper strip" and "outer paper strip" without thereby limiting the scope of the invention to paper as being the only material the strips can be made of.

[0017] It should be noted that if the strips (used to make the rod) are made of paper, the paper used preferably has a grammage in the interval [20; 200] g/sq m, more preferably in the interval [35; 170] g/sq m, and still more preferably in the interval [50; 150] g/sq m.

[0018] In an example embodiment, the apparatus also comprises a gluing unit configured to place glue on at least one of either the inside face of the outer strip or the outside face of the inner strip.

[0019] Alternatively (or in addition) to the gluing unit, the strips might be made of gum paper or other material able to be sealed (that is, permanently joined) by pressure.

[0020] The mandrel has a first end which is connected to a supporting element and a second end which is free.

[0021] The apparatus also comprises a belt; the belt is operatively wrapped (helically) around the outer paper strip in such a way that a movement of the belt causes the inner and outer strips to make a movement of rotation about the longitudinal axis of the mandrel and of translation along the same longitudinal axis in a feed direction (defined by a direction of travel of the mandrel from the first end to the second end of the mandrel itself). The belt is in contact with the outer strip along a contact surface which is helically disposed relative to the longitudinal axis of the mandrel. The belt is motor-driven.

[0022] The roto-translational (helical) movement of the paper strips causes the inner paper strip to rub against the mandrel.

[0023] The roto-translational (helical) movement of the paper strips causes a tubular rod to be formed which protrudes from the mandrel (from the second end of the mandrel); the tubular rod is made up of the inner and outer paper strips which are helically wrapped and glued to each other. The apparatus also comprises a cutting station located downstream of the belt and, preferably, downstream of the mandrel.

[0024] The cutting station is configured to cut the tubular paper rod protruding from the mandrel into pieces to make the semifinished products; in effect, each piece of rod is a semifinished product because, generally speaking, it is designed to be cut into smaller pieces before being inserted into a cigarette or other smokers' article.

[0025] The cutting station preferably comprises at least one blade (or other cutting element, such as a laser ray or beam) whose function is to intercept and cut the rod. Preferably, the blade is positioned in a cutting plane perpendicular to the longitudinal axis of the mandrel, which coincides with the longitudinal axis of the tubular rod to be cut. Preferably, the blade is mounted on a carrier unit. The carrier unit is movable along a trajectory defined by a closed line which might, for example, be contained in a displacement plane. The displacement plane is inclined to the cutting plane, so that the cutting plane is movable along the longitudinal axis by effect of the displacement of the carrier unit along the trajectory contained in the displacement plane. Preferably, the trajectory of the carrier unit is a circular trajectory around an axis of rotation which is inclined to the cutting plane (the axis of rotation is perpendicular to the displacement plane). The cutting station allows precise cutting of tubular rods moving at particularly high speeds (for example, from 10 to 720 m/min) obtaining pieces of suitably reduced length (for example, 60-180 mm).

[0026] It should be noted that during the displacement of the carrier unit, at least one endpoint of the blade describes a closed cutting line; preferably, this closed cutting line completely surrounds a cylinder defined by the tubular rod to be cut.

[0027] Preferably, only the inside face of the outer paper strip is glued; that is to say, the gluing unit applies an adhesive substance on the inside face of the outer paper strip; whereas the inner paper strip is fed to the mandrel without glue (or, more generally speaking, without adhesive substances). In an example embodiment, the apparatus comprises a scraping element. The scraping element interacts with a paper strip and is configured to position the strip in such a way as to receive the adhesive substance (glue or other similar substance). Thus, the scraping element is located upstream of the gluing unit.

[0028] It should be noted that the expressions "upstream" and "downstream" as used in this description, refer to a direction of paper movement from a paper reservoir (the different rolls which the paper is fed from) towards the cutting and outfeed station.

[0029] Preferably, the apparatus comprises a scraping element for each paper strip that is smeared with adhesive substance. Preferably, the scraping element acts on the inside face of the outer paper strip (which is preferably the only one to receive the adhesive substance).

[0030] In an example embodiment, the apparatus comprises a strain-relieving element. The strain-relieving element interacts with a paper strip and is configured to predispose it to be helically wrapped around the mandrel. Preferably, the apparatus comprises a strain-relieving element for each paper strip. Preferably, the apparatus comprises an outer strain-relieving element and an inner strain-relieving element acting on the outer paper strip and on the inner paper strip, respectively.

[0031] The motor-driven belt is preferably looped around at least a first and a second pulley. In an example embodiment, the first and second pulleys rotate about respective axes of rotation. In an example embodiment, the driving pulley is perpendicular to the longitudinal axis of the mandrel. It should be noted that in an example embodiment, the axis of rotation of the driven pulley might not be parallel to that of the driving pulley.

[0032] For example, the longitudinal axis of the mandrel is horizontal, that is, parallel to a flat surface on which the machine rests; preferably, the axes of rotation of the belt movement pulleys are also horizontal.

[0033] The belt is looped around the first and second pulleys, defining a forward section and a return section. Preferably, the forward and return sections of the belt cross each other.

[0034] One of the two sections of the belt - for example, the forward section - is wrapped around the mandrel. Preferably, the belt is wrapped around the mandrel to define a (preferably single) complete spiral. Preferably, the belt is wrapped around the mandrel at an angle of between 30 and 60 degrees.

[0035] The forward section (that is, the branch of the belt wrapped around the mandrel) has a first stretch, connecting the first pulley and the mandrel, and a second stretch, connecting the second pulley and the mandrel. Preferably, the first stretch of the forward section of the belt defines a ninety degree twist in a first direction, whilst the second stretch of the forward section of the belt defines a ninety degree twist in a second direction opposite to the first direction.

[0036] In an example embodiment, the apparatus comprises an outfeed station, located downstream of the cutting station and configured to receive and manipulate the pieces of tubular rod.

[0037] Preferably, the outfeed station is configured to transfer the pieces of rod leaving the apparatus along an outfeed direction transverse (in particular, perpendicular) to the longitudinal axis of the mandrel (and of the rod).

[0038] In an example embodiment, the outfeed station comprises a drum which rotates about an axis parallel to the longitudinal axis of the mandrel. The drum has a plurality of housings on its periphery. Preferably, these housings are equispaced. Preferably, the width of each housing of the plurality, measured tangentially to the drum, decreases in the feed direction of the tubular rod. This allows the pieces of tubular rod to be manipulated quickly and precisely, without damaging them.

[0039] More specifically, the pieces of rod are received in the housings of the drum and held therein by suction; thus, the pieces are held in suction housings, which are spaced from each other, and are then fed out transversely to another machine located downstream of the apparatus which makes the pieces of rod.

[0040] In an example embodiment, the apparatus comprises a heater operating in a space located downstream of the gluing unit and upstream of the cutting station. For example, the apparatus comprises a heated beam in a zone of the apparatus which includes the mandrel.

[0041] With regard to the mode of wrapping the paper strips around the mandrel, attention is drawn to the following:
Preferably, the inner strip is wrapped around the mandrel with a (first) predetermined spacing and with coils that are juxtaposed with each other without overlapping. Preferably, the outer strip is wrapped around the mandrel with a (second) predetermined spacing and with coils that are juxtaposed with each other without overlapping. In one embodiment, the first predetermined spacing is equal to the second predetermined spacing. It should be noted that (in possible example embodiments not illustrated), the coils might overlap each other (to a predetermined extent). In possible example embodiments not illustrated, there might be a (predetermined) gap between the coils (ends remaining distant). Mixed solutions are also imaginable (where different strips are wrapped in different ways), for example where one of the strips is wrapped precisely (without overlapping and without gaps) and another is wrapped loosely (with a gap between the coils); or, in another example, with one layer (for example, the one formed by the inner strip) with overlapping and another, precise layer on top of that.

[0042] Preferably, the inner strip and the outer strip are wrapped at the same spacing Preferably, the coils of the outer strip are longitudinally offset relative to the coils of the inner strip by a predetermined quantity (for example, half the spacing).

[0043] Preferably, the apparatus comprises an outer roll of outer paper web and an inner roll of inner paper web. Preferably, in one length of formed product, a greater length of outer paper strip is used. Preferably, therefore, the total length of the outer web is greater than that of the inner web. Preferably, the width of the outer web is greater than that of the inner web.

[0044] The inner roll is used to feed the inner paper strip and the outer roll is used to feed the outer paper strip.

[0045] According to another aspect of the apparatus of this description, a single tubular rod is formed ("single-rod" apparatus) but two tubular rods ("twin-rod" apparatus) or more in general, a plurality of tubular rods, might also be formed simultaneously.

[0046] With the necessary changes made and unless otherwise specified, all the aspects described in the foregoing apply to single-rod, twin-rod and other apparatuses of this kind.

[0047] The formation of two (or more) rods simultaneously allows further increasing the productivity of the apparatus.

[0048] In the case where the apparatus is configured to form a plurality of rods simultaneously, the machine comprises, for each rod of the plurality, a respective assembly comprising one mandrel, two or more paper strips (at least one inner and one outer), one motor-driven belt and one gluing unit; the cutting (and outfeed) station, on the other hand, may be the same one for all the rods (or there may be one for each rod).

[0049] With regard to the multi-rod apparatus, this description concentrates primarily (without thereby losing in generality) on the example in which two rods are formed simultaneously (twin-rod machine).

[0050] In the case where two tubular rods are formed simultaneously, the apparatus comprises a second mandrel, a second inner paper strip, a second outer paper strip and a second motor-driven belt, in addition to the inner paper strip, outer paper strip and motor-driven belt mentioned above, which define a first mandrel, a first inner paper strip, a first outer paper strip and a first motor-driven belt, respectively.

[0051] It should be noted that when the term "mandrel" is used in this description, the apparatus being generically referred to is one having one or more mandrels, where the mandrel is, in effect, a first mandrel; the expression "first mandrel" is used to mean the same element but indicates that the machine has at least a first and a second mandrel.

[0052] The second inner and outer strips are wrapped around the second mandrel and the second belt acts on the second outer strip to form a second tubular rod.

[0053] Preferably, the (twin-rod) apparatus comprises an outer roll of outer web and an inner roll of inner web. The (twin-rod) apparatus preferably also comprises at least one cutting unit configured to cut the inner web and the outer web longitudinally to create respective pairs of a first and a second half-web. The first and second half-webs obtained from the inner web are wrapped around the first and second mandrels, respectively, to define the first and second inner strips, respectively. The first and second half-webs obtained from the outer web are wrapped around the first and second mandrels, respectively, to define the first and second outer strips, respectively.

[0054] This solution makes it possible to reduce the costs (including operating costs) of the apparatus.

[0055] Instead of cutting the webs longitudinally, a twin-rod apparatus may have single-width rolls and four paper feed units (for example, duplicating the architecture described for the single rod apparatus).

[0056] Thus, in the twin-rod apparatus, the webs are twice as wide as the strips (in the single-rod apparatus, on the other hand, the inner web preferably coincides with the inner strip and the outer web coincides with the outer strip).

[0057] In an example embodiment of the twin-rod machine, the apparatus comprises, for each, inner and outer web, or for each cutting unit, a first, second and third unwinding unit and a first, second and third adjusting unit (also called "dandy rollers").

[0058] The first unwinding unit and the first adjusting unit are located downstream of the cutting unit (inner or outer) and are coupled to the first paper strip (inner or outer, respectively).

[0059] The second unwinding unit and the second adjusting unit are located downstream of the cutting unit (inner or outer) and are coupled to the second paper strip (inner or outer, respectively).

[0060] The third unwinding unit and the third adjusting unit are located upstream of the cutting unit (inner or outer) and are coupled to the corresponding web (inner or outer, respectively).

[0061] Each unwinding unit has its own motor-driven feed roller.

[0062] Each adjusting unit has its own system of reciprocally movable transmission rollers for lengthening and shortening the path of the respective paper strip or web.

[0063] This system of (motor-driven) unwinding units is designed (using a controlled adjustment unit with corresponding actuators of the unwinding units) to dynamically balance the tensional forces at the ends of the three layers of paper associated with the same cutting unit.

[0064] More specifically, the first and second adjusting units are controlled to adopt (significantly) different positions when the machine is started in order to allow starting the second mandrel with a time delay after the first mandrel.

[0065] Preferably, the second mandrel is oriented along a longitudinal axis parallel to the longitudinal axis of the first mandrel.

[0066] In an example embodiment, the first, inner and outer paper strips are wrapped around the first mandrel in a first rotation direction and the second, inner and outer paper strips are wrapped around the second mandrel in a second rotation direction, opposite to the first rotation direction. Further, the first and second belts are looped around respective pairs of pulleys, each of the pairs having respective axes of rotation passing through a respective plane; the position planes of the axes of rotation of the two pairs of pulleys preferably intersect (for example, if the inclination of the belt on the mandrel is 45 degrees, they intersect at right angles).

[0067] This allows reducing the dimensions of the (twin-rod) apparatus and makes it easier for the user to access the mandrel zone.

[0068] It should be noted that in an example embodiment, the apparatus (and in particular the paper feed section) includes guides, or guiding devices (not illustrated in the drawings) located upstream of the mandrel and configured to guide the strips along one stretch of their path adjacent to the mandrel around which the strips themselves are wrapped.

[0069] In an example embodiment, the apparatus (and in particular the paper feed section) includes at least one friction reducer (device) configured to reduce the friction between the inside of the inner strip and the mandrel; this friction reducer (not illustrated in the drawings) acts on the inside face of the inner strip.

[0070] This description also provides a method for making semifinished products intended to form part of smokers' articles.

[0071] The method comprises a step of preparing an inner paper strip and wrapping it helically around a stationary mandrel which is elongate along a longitudinal axis. There is also a step of preparing an outer paper strip which is operatively wrapped helically around the inner paper strip, with an inside face of the outer strip in contact with an outside face of the inner strip.

[0072] The method also comprises a step of gluing at least one of either the inside face of the outer strip or the outside face of the inner strip; the term "gluing" is used in a broad sense to indicate application of an adhesive substance. Preferably, only the inside face of the outer strip is subjected to gluing.

[0073] The method also comprises a step of moving a motor-driven belt wrapped helically around the outer paper strip in order to impart to the inner and outer paper strips a movement of rotation about the longitudinal axis of the mandrel and of translation along that axis in a direction of feed.

[0074] As the strips wrapped around the mandrel move in the feed direction, a tubular rod is formed (from the inner and outer strips joined to each other) and fed continuously along the longitudinal axis of the mandrel in the feed direction. Also, as the strips wrapped around the mandrel move in the feed direction, the inner and outer strips are fed by unwinding respective inner and outer paper rolls.

[0075] The method also comprises a step of cutting the tubular rod fed downstream of the mandrel. The cut involves the action of a blade (or other substantially flat cutting element) oriented in a cutting plane perpendicular to the longitudinal axis (of the mandrel and rod). The blade moves along a trajectory (defining a closed line), preferably a circular trajectory about an axis of rotation which is inclined to the cutting plane. Thus, during the cutting action, the blade and the cutting plane move along the longitudinal axis, following the feed movement of the rod. More specifically, while it cuts the rod, the blade moves at a speed which has a translational component along the longitudinal axis in the feed direction; this component is, preferably, equal to the feed speed of the rod along the longitudinal axis (with reference to the translational component of rod speed).

[0076] The cutting step is followed by an outfeed step in which the pieces of tubular rod are fed into longitudinal housings on the rotating drum; these pieces are then fed out of the apparatus transversely to the longitudinal axis of the mandrel and rod.

[0077] In an example embodiment, the method comprises forming two (or more) tubular paper rods simultaneously.

[0078] In this example embodiment, the method comprises step of preparing a second mandrel, a second inner paper strip, a second outer paper strip and a second motor-driven belt.

[0079] There is also a step of preparing an outer roll of outer web and an inner roll of inner web.

[0080] The method comprises a step of cutting the inner web and the outer web longitudinally to create respective pairs of a first and a second half-web. The first and second half webs obtained from the inner web define the first and second inner strips, respectively, and the first and second half webs obtained from the outer web define the first and second outer strips, respectively.

[0081] In an example embodiment, for each inner web and outer web, there are steps of unwinding and adjusting the first paper strip (after cutting the respective web), of unwinding and adjusting the second paper strip (after cutting the respective web) and of unwinding and adjusting the respective web, before cutting it.

[0082] The steps of unwinding and adjusting the first and second paper strips and the respective web are carried out by corresponding first, second and third unwinding units and first, second and third adjusting units.

[0083] There is also a step of automatically controlling the first, second and third unwinding units and adjusting units as a function of the detected tension of the first and second strips and of the web.

[0084] Whether or not there are one or more mandrels, there is a step (for each of the one or more mandrels) of relieving the strain of the paper strips (by applying mechanical stress) and for the strips subjected to gluing, there is a scraping step.

[0085] It should be noted that the inner and outer strips are wrapped around the mandrel at the same spacing and with the respective coils disposed relative to each other in a predetermined manner (for example, precisely juxtaposed, without overlapping or gaps, or with predetermined overlapping, or loosely and leaving a predetermined gap).

[0086] This description also provides a piece of tubular rod or a portion thereof obtained by further cutting the piece along a cutting plane perpendicular to the longitudinal axis of the piece. The piece or portion of a piece of tubular rod defines a cylindrical paper ring extending round a longitudinal axis. The ring has an outer layer and an inner layer. The outer layer is made up of a number (which may also be fractional) of coils of a paper strip wrapped helically along the longitudinal axis. The inner layer is made up of a number (which may also be fractional) of coils of a paper strip wrapped helically along the longitudinal axis. Preferably, the inner layer and the outer layer are made up of the same number of coils of the respective paper strip. The coils of the outer paper strip are wrapped at the same spacing as the coils of the inner paper strip. In an example embodiment, the coils of the outer paper strip are juxtaposed with each other without gaps or overlapping, and the coils of the inner paper strip are juxtaposed with each other without gaps or overlapping (but with other machine settings, as described above).

[0087] The inner paper strip is preferably smaller in length than the outer paper strip; this has the effect of eliminating a gap that would otherwise form on the outer layer of equal width.

[0088] The ratio between the width of the inner (or outer) paper strip and the diameter of the tubular element is preferably in the interval [1.5 - 2.7]; more preferably, this ratio is in the interval [1.8 - 2.5]; still more preferably, this ratio is in the interval [2.1 - 2.4].

[0089] The width of the inner (or outer) paper strip is preferably in the interval [4.5 - 24.5] mm; more preferably, this width is in the interval [5.5 - 22.5] mm; still more preferably, this width is in the interval [6.5 - 21.5] mm.

[0090] This description also provides a cigarette (or cigar or other like smokers' article) comprising one or more of the aforementioned paper rings.

Brief description of the drawings

[0091] This and other features will become more apparent from the following description of a preferred embodiment, illustrated purely by way of non-limiting example in the accompanying drawings, in which:

- Figure 1 illustrates an apparatus for making semifinished products intended to form part of smokers' articles, according to this description;

- Figure 2A schematically illustrates a semifinished product consisting of a piece of rod;

- Figure 2B schematically illustrates a portion of the rod of Figure 2A;

Figure 3 shows the apparatus of Figure 1 with some parts cut away and others illustrated schematically;

- Figure 4 is a functional diagram of the apparatus of Figure 1;

Figure 5 illustrates a detail of the apparatus of Figure 1;

- Figure 6 shows the detail of Figure 5 according to an alternative embodiment of the apparatus of Figure 1;

- Figure 7 shows the functional diagram of Figure 4 for the variant embodiment of the apparatus of Figure 6;

- Figure 8 illustrates a detail of the apparatus of Figure 1, showing the cutting and outfeed stations in a top view;

- Figure 9 is a side view of the detail of Figure 8;

- Figures 10A, 10B and 10C illustrate a succession of operating conditions of the outfeed station of Figure 9.

Detailed description of preferred embodiments of the invention

[0092] With reference to the drawings, the numeral 1 denotes an apparatus for making semifinished products intended to form part of smokers' articles. The apparatus 1 is a spiral wrapping machine.

[0093] The machine 1 is designed to make pieces 200 of a paper tube, constituting the semifinished products. For this purpose, the apparatus 1 forms a tubular paper rod 2A from which the pieces 200 are obtained by cutting. Depending on the embodiment of it, the apparatus forms a single tubular rod 2A or two or more such rods simultaneously. Where a plurality of rods are formed simultaneously, this description refers to the rod 2A as a first rod formed at the same time as (at least) a second rod 2B.

[0094] The apparatus 1 comprises a section 3 for feeding the paper and a section 4 for forming the rod 2A (or the rods). The apparatus 1 also comprises a section 5 for cutting the rod (or rods) to make the pieces 200. The apparatus preferably also comprises an outfeed station 6 which receives the pieces 200 from the cutting station 5 and manipulates them to make them available to another machine (such as, for example, a machine for making cigarette filters) located downstream of the apparatus 1, or to place them in a reservoir of pieces 200.

[0095] The specification below describes first of all the embodiment which makes a single rod and then the embodiment which makes a plurality of rods, with non-limiting reference by way of example to two rods.

[0096] The apparatus 1 comprises a (first) mandrel 401A which is elongate along a longitudinal axis 402A; the mandrel is a stationary mandrel 401A, that is to say, it does not move relative to the fixed parts of the apparatus 1 during operation of the apparatus 1.

[0097] The apparatus 1 comprises a (first) inner paper strip 7A. The inner strip 7A is operatively wrapped helically around the mandrel 401A.

[0098] The apparatus 1 comprises a (first) outer paper strip 8A. The outer strip 8A is operatively wrapped helically around the inner strip 7A wrapped around the mandrel 401A. At the mandrel 401A, an inside face of the outer strip 8A is in contact with an outer face of the inner strip 7A.

[0099] The apparatus 1 comprises a (first) belt 403A. Preferably, the belt 403A is motor-driven. For example, the belt 403A is coupled to (stretched between) a first pulley 404A and a second pulley 405A, where at least one of the pulleys is motor-driven.

[0100] The belt 403A is in contact with the outer strip 8A, so that a movement of the belt causes a corresponding movement of the inner strip 7A and outer strip 8A relative to the mandrel 401A. Preferably, the belt 403A acts on the outer strip (8A) to impart to the inner strip 7A and outer strip 8A a movement of rotation about the longitudinal axis 402A of the mandrel 401A and of translation along the axis 402A in a direction of feed. Preferably, the belt 403A is in contact with the outer strip 8A along a contact surface which is helically disposed relative to the longitudinal axis 402A of the mandrel 401A.

[0101] In an example embodiment, the first pulley 404A and the second pulley 405A have respective axes of rotation which are parallel to each other; preferably, the axes of rotation of the first pulley 404A and second pulley 405A are inclined (not perpendicular) to the longitudinal axis 402A.

[0102] The belt 403A is looped around the first and second pulleys 404A and 405A, defining a forward section 406A and a return section 407A. In an example embodiment, the forward section 406A and the return section 407 cross each other.

[0103] The forward section 406A is wrapped around the mandrel 401A and defines a first stretch 408A, connecting the first pulley 404A and the mandrel 401A, and a second stretch 409A, connecting the second pulley 405A and the mandrel 401A.

[0104] Preferably, the first stretch 408A of the forward section 406A of the belt 403A defines a twist in a first direction; this twist is preferably a ninety degree twist.

[0105] Preferably, the second stretch 409A of the forward section 406A of the belt 403A defines a twist in a second direction, opposite to the first direction; this twist, too, is preferably a ninety degree twist.

[0106] Preferably, the forward section 406A of the belt 403A is inclined at a predetermined angle to the mandrel 401A; preferably, this inclination angle is between 30 and 60 degrees.

[0107] The belt 403A (in particular, the forward section 406A of the belt 403A) is wrapped around the mandrel 401A (in particular, around the outer strip 8A) with one coil; preferably at least one full coil; preferably one coil and one coil only.

[0108] In an example embodiment, the first and second pulleys 404A, 405A are rotatably coupled to a front supporting arm 410A. The axes of rotation of the first and second pulleys 404A, 405A (preferably parallel) are contained in a first position plane; the first position plane is preferably inclined to the longitudinal axis 402A of the mandrel 401A.

[0109] The mandrel 401A, the belt 403A and the related pulley system, form part of the station 4 for forming the rod 2A. The forming station 4 is configured to receive the inner and outer paper strips 7A and 8A and to wrap them helically around each other and around the mandrel 401A, in a continuous process where the tubular rod 2A advances progressively from the mandrel 401A and the inner and outer paper strips 7A and 8A are progressively pulled.

[0110] The apparatus 1 also comprises a gluing unit 301 (also called "gummer").

[0111] The gluing unit 301 is configured to deposit an adhesive substance on at least one of either the inside face of the outer strip 8A or the outside face of the inner strip 7A. The adhesive substance is preferably a liquid or semiliquid glue (for example, vinyl glue).

[0112] Preferably, the gluing unit 301 is located in the paper feed section so that the inner and outer strips 7A and 8A have adhesive substance on them when they reach the mandrel.

[0113] Preferably, the adhesive substance is applied only on the inside face of the outer strip 8A. The gluing unit 301A, therefore, is preferably located along the unwinding path of the outer paper strip 8A; the inner paper strip 7A preferably has no glue on it when it is fed to the mandrel 401A.

[0114] In an example embodiment, the apparatus 1 comprises at least one scraping element 302A located upstream of the gluing unit 301A.

[0115] The scraping element 302A is configured to treat a surface of one of the paper strips in such a way as to prepare it to optimally receive the adhesive substance. The scraping element 302A is of essentially known type and is not described in further detail here. Preferably, the scraping element 302A is located along the unwinding path of the outer paper strip 8A to treat the inside face of the outer paper strip 8A.

[0116] In an example embodiment, the apparatus 1 comprises at least one strain-relieving element 303A; the strain-relieving element 303A is configured to interact with one or more strips of paper to subject them to a mechanical stress which predisposes them to be spirally wrapped. The strain-relieving element 303A is of essentially known type and is not described in further detail here.

[0117] In an example embodiment, the apparatus 1 comprises an inner strain-relieving element 303A and an outer strain-relieving element 304A. The inner strain-relieving element 303A operates on the inner paper strip 7A; the outer strain-relieving element 304A operates on the outer paper strip 8A.

[0118] The outer strain-relieving element 304A is preferably located upstream of the gluing unit 301A. The outer strain-relieving element 304A is preferably located downstream of the scraping element 302A. The inner strain-relieving element 303A and the outer strain-relieving element 304A may be made as a single structure or as two separate structures.

[0119] It should be noted that the scraping element 302A and the strain-relieving element 304A form part of the paper feed section 3. In a possible embodiment, the scraping element and the strain-relieving element coincide, in the sense that a single element performs both the scraping and strain-relieving function.

[0120] It should be noted that the apparatus 1 (and in particular the feed section 3) also comprises a plurality of transmission rollers 305 coupled to corresponding paper strips to keep them in a tensioned condition and define a predetermined path for them.

[0121] In an example embodiment, the apparatus 1 also comprises an inner paper roll 306 and an outer paper roll 307. The function of the inner roll 306 is to feed the inner strip 7A and the function of the outer roll 307 is to feed the outer strip 8A. Downstream of each roll, there is also an adjusting unit ("dandy roller").

[0122] With regard to the cutting station 5 of the apparatus 1, attention is drawn to the following.

[0123] The cutting station 5 is positioned downstream of the mandrel 401A to cut the pieces 200 of the tubular rod 2A of paper coming out of the mandrel 401A.

[0124] The cutting station 5 comprises a blade 501 configured to intercept and cut the rod 2A. The blade 501 is positioned in a cutting plane 502. Preferably, the cutting plane 502 is perpendicular to the longitudinal axis 402A. In an example embodiment, the blade 501 is mounted on a movable carrier unit 503. Preferably, the blade 501 is movable (for example as one with the carrier unit 503) along a closed trajectory; this movement is continuous. The trajectory of the blade 501 is preferably contained in a displacement plane 504 (meaning by this that any point on the blade 501 moves along the trajectory contained in the displacement plane). Preferably, the trajectory followed by the blade 501 is a circular trajectory around an axis of rotation 505 which is inclined to the cutting plane 502; the axis of rotation 505 is inclined to the longitudinal axis 402 of the mandrel 401A (which is also the axis of the rod 2B).

[0125] Thus, the cutting plane 502 is movable along the longitudinal axis 402; the cutting plane 502 is movable by translation along the longitudinal axis 402. The apparatus 1 comprises an actuator (of essentially known type and not illustrated) to move the blade 501 along its trajectory at a certain speed. The apparatus 1 comprises a control unit (not illustrated) having an electronic card provided with a memory and a processor.

[0126] The control unit is connected to the actuator of the blade 501 to control the speed of its displacement along its trajectory. Preferably, the control unit is programmed to set the displacement speed of the blade 501 along its trajectory as a function of the feed speed of the rod 2A along the longitudinal axis 402A in such a way that a component of the speed of the blade 501 directed along the longitudinal axis 402A is the same or directed in the same way as the feed speed of the rod 2A in the stretch of the trajectory where the blade 501 cuts the rod 2A.

[0127] It should also be noted that the cutting plane 502 and the displacement plane 504 are preferably inclined to each at a predetermined angle.

[0128] In an example embodiment, the apparatus comprises a plurality of blades 501 (for example, two) and, preferably, a plurality of carrier units 503 (for example, two).

[0129] In an example embodiment, the blade 501 is (or the blades 501 are) connected to a rotor 506, preferably cylindrical. Preferably, the carrier unit 503 is (or the carrier units 503 are) connected to the rotor 506. The rotor 506 is rotatable about the axis of rotation 505. Preferably, the blade 501 is (or the blades 501 are) connected to a periphery of the rotor 506; in the case of a plurality of blades 501, the blades are preferably positioned on the periphery of the rotor 506, spaced at equal angular intervals thereon. In an example embodiment, the axis 505 is adjustable in orientation relative to the cutting plane 502 and relative to the longitudinal axis 402 of the mandrel 401A. The inclination is adjusted as a function of the (translational) feed speed of the rod 2A along the longitudinal axis 402A.

[0130] It should be noted that the (translational) feed speed of the rod 2A along the longitudinal axis 402A is linked to the speed of the belt 403 and to the angle of incidence of the paper strips 7A and 8A relative to the mandrel 401A.

[0131] It should be noted that the inner paper strip 7A and the outer paper strip 8A are preferably wrapped around the mandrel 401A at the same spacing P. Preferably, the inner paper strip 7A and the outer paper strip 8A are wrapped around the mandrel 401A at the same angle of incidence Z. Preferably, the inner paper strip 7A and the outer paper strip 8A are wrapped around the mandrel 401A at an angle of incidence Z of between 30 and 60 sexagesimal degrees.

[0132] Preferably, the inner strip 7A is wrapped around the mandrel 401 with each coil juxtaposed with another (that is, with the next one), without overlapping (and without gaps). Preferably, the outer strip 8A is wrapped around the mandrel 401 with each coil juxtaposed with another (that is, with the next one), without overlapping (and without gaps). Preferably, the coils of the outer strip 8A are longitudinally offset relative to the coils of the inner strip 7A by a predetermined length Q; for example, the length Q is half the spacing P.

[0133] In an example embodiment, the apparatus 1 also comprises the outfeed station 6.

[0134] The outfeed station 6 is located downstream of the cutting station 5. The outfeed station 6 is configured to receive the pieces 200 of the tubular rod 2A.

[0135] In an example embodiment, the outfeed station 6 comprises one or more drums 601 which rotate about respective outfeed axes of rotation 602 parallel to the longitudinal axis 402A of the mandrel 401A.

[0136] The (or each) drum 601 has a plurality of housings 603 formed on the periphery of the drum 601 itself. The housings 603 are configured to receive corresponding pieces 200. Preferably, the housings 603 are angularly equispaced along the periphery of the drum 601. Also, the outfeed station 6 might have a first and a second drum 601, counterrotating and juxtaposed, in order to increase the speed at which the cut pieces 200 are fed out.

[0137] In an example embodiment, the width of each housing 603 of the plurality, measured tangentially to the drum 601, decreases in the feed direction of the rod 2A, that is, in the feed direction of the pieces 200 from the cutting station 5 to the outfeed station 6.

[0138] Preferably, each housing 603 defines suction outlets connected to a suction unit to hold the pieces 200 in place when they are positioned in the housings 603.

[0139] It should be noted that in an example embodiment, the apparatus comprises a beam 9 configured to receive and guide the pieces 200 from the cutting station 5 to the outfeed station 6.

[0140] In an example embodiment, the apparatus 1 comprises a heater (not illustrated), consisting, for example, of electrical resistors, air jets, lamps or other known heating systems) configured to heat the rod 2A. Preferably, the heater operates in a space located downstream of the gluing unit 301A and upstream of the cutting station 5. For example, the heater is located in a zone of the apparatus where the beam is located; in an example embodiment, the beam itself is heated and thus constitutes a heating element.

[0141] Below is a description of a variant embodiment of the apparatus 1 which is configured to form a second rod 2B in addition to the (first) rod 2A described above.

[0142] The foregoing description of the single-rod machine also applies to the multi-rod machine, or twin-rod machine.

[0143] The apparatus 1 for (simultaneously) forming a first and a second rod 2A, 2B comprises (in addition to the mandrel 401A, inner strip 7A, outer strip 8A and belt 403A, which constitute a first mandrel 401A, a first inner strip 7A, a first outer strip 8A and a first power-driven belt 403A), a second mandrel 401B, a second inner paper strip 7B, a second outer paper strip 8B and a second belt 403B. The second inner and outer strips 7B, 8B are wrapped around the second mandrel 401B and the second belt 403B acts on the second outer strip 8B to form a second tubular paper rod 2B.

[0144] With regard to the elements (301A, 302A, 303A, 304A) of the paper feed section 3 and the elements (401A, 402A, 403A, 404A, 405A, 406A, 407A, 408A, 409A, 410A) of the forming section 4, the apparatus 1 for (simultaneously) forming a first and a second rod 2A, 2B comprises the same number of elements (denoted in the relevant drawings by the reference labels 301B, 302B, 303B, 304B, 401B, 402B, 403B, 404B, 405B, 406B, 407B, 408B, 409B, respectively) to which the foregoing description also applies (with the necessary changes made) and which, for brevity, will not be described again.

[0145] The description which follows applies to the part of the apparatus (with reference in particular to the paper feed section 3) which, in the apparatus 1, is configured to (simultaneously) form a first and a second rod 2A, 2B and which was not described above with regard to the single-rod machine. The second mandrel 401B is positioned along a second axis 402B; preferably, the second axis 402B of the second mandrel 401B is parallel to the longitudinal axis 402A of the first mandrel 401A, which means that the second axis 402B, too, is preferably a longitudinal axis.

[0146] The second belt 403B is looped around a third pulley 404B and a fourth pulley 405B. In an example embodiment, the third and fourth pulleys 404B, 405B are rotatably coupled to a rear supporting arm 410B. The axes of rotation of the third and fourth pulleys 404A, 405A (preferably inclined) are contained in a second position plane; the second position plane is preferably inclined to the longitudinal axis 402A of the mandrel 401A; the second position plane is preferably also inclined to the first position plane.

[0147] In an example embodiment, the first mandrel 401A and the second mandrel 401B are juxtaposed along a transverse direction, perpendicular to the longitudinal axis 402A of the first mandrel 401A. Relative to the transverse direction, the front supporting arm 410A (supporting the first and second pulleys 404A, 405A) and the rear supporting arm 410B (supporting the third and fourth pulleys 404B, 405B) are in successively juxtaposed relation with each other; the first mandrel 401A, the second mandrel 401B, the front arm 410A and the rear arm 410B are positioned in succession along the transverse direction (away from the paper feed section 3).

[0148] Preferably, the first mandrel 401A and the second mandrel 401B are offset from each other along the longitudinal direction.

[0149] In an example embodiment, the first, inner and outer paper strips 7A, 8A are wrapped around the first mandrel 401A in a first rotation direction and the second, inner and outer paper strips 7B, 8B are wrapped around the second mandrel 401B in a second rotation direction, opposite to the first rotation direction.

[0150] The inner roll 306 is formed from an inner web 10 greater in width than the first inner paper strip 7A (in the case of the single-rod machine, on the other hand, the inner roll 306 is the inner strip 7A itself wound in the form of a roll).

[0151] The outer roll 307 is formed from an outer web 11 greater in width than first outer paper strip 8A (in the case of the single-rod machine, on the other hand, the outer roll 307 is the outer strip 8A itself wound in the form of a roll).

[0152] The apparatus 1 also comprises a cutting system configured to cut the inner web 10 and the outer web 11 longitudinally in order to obtain from each web a first and a second half-web; the half-webs obtained from the inner web 10 constitute the first and second inner strips 7A, 7B; the half-webs obtained from the outer web 11 constitute the first and second outer strips 8A, 8B.

[0153] In an example embodiment, the apparatus 1 comprises an inner cutting unit 308 configured to cut the inner web 10 longitudinally (that is, along the main direction of extension), and an outer cutting unit 309 configured to cut the outer web 11 longitudinally; the inner and outer cutting units 308, 309 define the cutting system.

[0154] In an example embodiment, the apparatus 1 comprises inner and outer centring elements 3171, 317E (consisting, for example, of movable rollers) located upstream of the inner and outer cutting units 308, 309, to centre the webs 10 and 11 relative to the cutting units 308, 309 themselves.

[0155] In an example embodiment, the apparatus 1 comprises inner and outer separating elements 3161, 316E located downstream of the inner and outer cutting units 308, 309, to separate the half-webs just cut and to form distinct paper strips. For example, the separating elements comprise rollers or pulleys or other transmission systems.

[0156] In an example embodiment, the apparatus 1 comprises: a first, a second and a third inner unwinding unit 3101, 3111 and 3121; a first, a second and a third inner adjusting unit 3131, 3141 and 3151; a first, a second and a third outer unwinding unit 310E, 311E and 312E; a first, a second and a third outer adjusting unit 313E, 314E and 315E.

[0157] Each unwinding unit 3101, 3111, 3121, 310E, 311E, 312E comprises, for example, motor-driven rollers acting on a corresponding strip or web to keep it under tension and move it.

[0158] Each adjusting unit 3131, 3141, 3151, 313E, 314E, 315E comprises, for example, a plurality of pulleys or rollers mounted at variable distances from one another for lengthening and shortening the path of the paper (strip or web) coupled thereto; these rollers or pulleys may be idle and preferably have swinging axes of rotation to compensate or relieve tension on the strips or webs.

[0159] The first inner unwinding unit 3101 is located downstream of the inner cutting unit 308 and is coupled to the first inner paper strip 7A.

[0160] The first inner adjusting unit 3131 is located downstream of the inner cutting unit 308 and is coupled to the first inner paper strip 7A. The first inner adjusting unit 3131 interacts with the first inner unwinding unit 3101. The second inner unwinding unit 3111 is located downstream of the inner cutting unit 308 and is coupled to the second inner paper strip 7B.

[0161] The second inner adjusting unit 3141 is located downstream of the inner cutting unit 308 and is coupled to the second inner paper strip 7B. The second inner adjusting unit 3141 interacts with the second inner unwinding unit 3111.

[0162] The third inner unwinding unit 3121 is located upstream of the inner cutting unit 308 and is coupled to the inner web 10.

[0163] The third inner adjusting unit 3151 is located upstream of the inner cutting unit 308 and is coupled to the inner web 10. The third inner adjusting unit 3151 interacts with the third inner unwinding unit 3121.

[0164] The first outer unwinding unit 310E is located downstream of the outer cutting unit 309 and is coupled to the first outer paper strip 8A.

[0165] The first outer adjusting unit 313E is located downstream of the outer cutting unit 309 and is coupled to the first outer paper strip 8A. The first outer adjusting unit 313E interacts with the first outer unwinding unit 310E. The second outer unwinding unit 311E is located downstream of the outer cutting unit 309 and is coupled to the second outer paper strip 8B.

[0166] The second outer adjusting unit 314E is located downstream of the outer cutting unit 309 and is coupled to the second outer paper strip 8B. The second outer adjusting unit 314E interacts with the second outer unwinding unit 311E.

[0167] The third outer unwinding unit 312E is located upstream of the outer cutting unit 309 and is coupled to the outer web 11.

[0168] The third outer adjusting unit 315E is located upstream of the outer cutting unit 309 and is coupled to the outer web 11. The third outer adjusting unit 315E interacts with the third outer unwinding unit 312E.

[0169] The control unit of the apparatus is connected to the actuators of the unwinding units 3101, 3111, 3121, 310E, 311E, 312E and adjusting units 3131, 3141, 3151, 313E, 314E, 315E to balance the tensional forces at the inner and outer cutting units 308, 309 between the three stretches of paper leading to the respective cutting unit 308, 309, that is, the first and second strips (inner and outer), downstream, and the web (inner and outer), upstream.

[0170] Preferably, when the apparatus 1 is started, one of the two rods (for example the first rod 2A) starts being formed before the other rod (for example, the second rod 2B) starts being formed. Thus, when the machine is started, there is a time interval in which the first belt 403A is in motion and the first rod 2A is being formed, whilst the second belt 403B is stationary and the second rod 2B is not being formed yet. During this time interval, the first strips 7A and 8A, inner and outer, are pulled by the first belt 403A, so both the cutting units 308 and 309, inner and outer, must be in operation to unwind the respective first strips 7A and 8A and make them available to the forming section 4 (to the first mandrel 401A). In the same time interval, however, the second belt 403B does not apply any pulling action on the second strips 7B and 8B, inner and outer, and so, downstream of the cutting units 308 and 309, inner and outer, the respective adjusting units 3141 and 314E accumulate the paper being unwound (all the unwinding units are in operation) but which is not yet being pulled by the second belt 403B to form the second rod 2B, thus keeping all the paper strips at the correct tension.

[0171] In an example embodiment, the outer unwinding and adjusting units 310E, 311E, 312E, 313E, 314E, 315E are positioned upstream of the gluing units 301A, 301B relative to a path defined by the first and second outer strips 8A, 8B. In an example embodiment, the outer unwinding and adjusting units 310E, 311E, 313E, 314E are positioned downstream of the scraping elements 302A, 302B.relative to a path defined by the first and second outer strips 8A, 8B; and may be upstream or downstream of the strain-relieving elements 304A, 304B.

[0172] It should be noted that the inner roll 306 and the outer roll 307 preferably have different characteristics because the width of the outer roll 307 is preferably greater than that of the inner roll 306 and the respective outer web 11 is preferably wider than the inner web 10.

[0173] In a preferred example embodiment, the cutting station 5 is in common with both the first and the second rod 2A, 2B. Alternatively, the cutting station 5 might comprise one blade for cutting the first rod 2A and another blade for cutting the second rod 2B, where both of the blades are connected to the same movement structure (for example to the same rotor 506); or different blades might be connected to different, but preferably coordinated, movement structures.

[0174] Preferably. all the pieces 200 cut (from all the rods) converge on the same outfeed station 6 (which is in common).

[0175] In an example embodiment, the apparatus comprises heating elements located in the feed section 3, upstream of the mandrel 401A (or of the mandrels if there is more than one).

[0176] In an example embodiment, the apparatus 1 is modular, that is to say, one or more parts of it are replaceable with others to perform different functions. For example, the beam and the forming section 4 may be replaced with another beam and another forming section configured to process tow to form a rod of tow (defining a cylinder of tow) according to technology of essentially known type, instead of a tubular rod of spirally wrapped paper.

[0177] Operatively, the operation of the apparatus is as described below, with reference to the embodiment which forms a single rod 2A.

[0178] The inner roll 306 feeds the inner strip 7A of paper which is wrapped helically around the mandrel 401A. Downstream of the inner roll 306, the inner strip 7A is preferably unwound and adjusted (in its path and hence also in its tension) by an inner unwinding unit 3121 and an inner adjusting unit 3151.

[0179] At the same time, the outer roll 307 feeds the outer paper strip 8A which is wrapped helically around the inner paper strip 7A. Downstream of the outer roll 307, the outer strip 8A is preferably unwound and adjusted (in its path and hence also in its tension) by an outer unwinding unit 312E and an outer adjusting unit 315E.

[0180] Upstream of the mandrel 401A, an adhesive substance (glue) is applied to the outer strip 8A, on the inside face thereof (that is, the face which is in contact with the inner strip 7A and will be on the inside of the tube defining the rod 2A).

[0181] Preferably, the outer strip 8A is heated after applying the adhesive substance to it and before wrapping it around the mandrel 401A. Preferably, the rod 2A is heated before being cut.

[0182] During its formation, the rod 2A proceeds along the longitudinal axis of the mandrel and passes the second end (the free end) of the mandrel 401A, in a zone where there is only air inside the rod 2A.

[0183] Cutting the rod 2A into pieces is carried out preferably in that zone, where it is clear of the mandrel 401A.

[0184] Preferably, the pieces 200 are cut off perpendicularly to the rod 2A by a blade 501 which, as it cuts, progressively moves longitudinally in the feed direction of the rod 2A so there is no longitudinal relative speed between the rod 2A and the blade 501.

[0185] Preferably, during cutting, the blade completely intercepts the cylinder defined by the rod 2A.

[0186] In the case where two (or more) rods 2A, 2B are formed simultaneously, the steps listed above are duplicated for the two pairs of paper strips used to form the two rods and, in addition to these steps, the following further steps are carried out:
Preferably, two rolls are used (but in an alternative embodiment, four might be used): an inner roll to provide the first and second inner strips 7A, 7B; and an outer roll to provide the first and second outer strips 8A, 8B. Thus, the inner roll 306 is formed from an inner web 10 whose width is equal to the sum of the widths of the first and second inner strips 7A, 7B; similarly, the outer roll 307 is formed from an outer web 11 whose width is equal to the sum of the widths of the first and second outer strips 8A, 8B. Preferably, between the rolls 306, 307 and the forming section 4 (preferably upstream of the gluing units), the inner and outer webs 10, 11 are cut (and separated) longitudinally to form the first and second inner strips 7A, 7B and the first and second outer strips 8A, 8B.

[0187] Before and after cutting the webs longitudinally, the unwinding and length of the webs or cut strips are adjusted to prevent the paper from losing tension and becoming slack.

[0188] Irrespective of the number of rods, the pieces 200, after being cut off, are preferably received in longitudinally elongate housings rotating about longitudinal axes (and held therein by suction) and then fed out to a machine downstream, transversely to the longitudinal direction of extension of the rod 2A.

[0189] It is observed that, in the present document, the following expressions: the mandrel 401A, the inner strip 7A (of paper), the outer strip 8A (of paper) and the belt 403A, are to be intended, when they are referred to the embodiment with two or more rods, are to be construed as follows: at least the first or the second mandrel 401A, 410B, at least the first or the second inner strip 7A, 7B (of paper), at least the first or the second outer strip 8A, 8B (of paper) and at least the first or the second belt 403A, 403B.

Claims

1. An apparatus (1) for making semifinished products forming part of smokers' articles, comprising:

- a stationary mandrel (401A) elongate along a longitudinal axis (402A);

- an inner strip (7A) of paper operatively wrapped helically around the mandrel (401A);
at least one outer strip (8A) of paper operatively wrapped helically around the inner strip (7A), with an inside face of the outer strip in contact with an outside face of the inner strip;

- a power-driven belt (403A) operating on the outer strip (8A) to impart to the inner and outer strips (7A, 8A) a movement of rotation about the longitudinal axis (402A) of the mandrel and of translation along the axis in a direction of feed, wherein the belt (403A) is in contact with the outer strip (8A) on a contact surface helically disposed relative to the longitudinal axis (402A);

- a cutting station (5) positioned downstream of the mandrel (401A) for cutting pieces (200) of a tubular rod (2A) of paper coming out of the mandrel (401A) and made up of the inner and outer strips (7A, 8A) of paper glued to each other, wherein the cutting station (5) comprises a blade (501) for intercepting and cutting the rod (2A),

characterized in that the blade (501) is disposed in a cutting plane (502) perpendicular to the longitudinal axis (402A) and is movable along a circular trajectory around an axis of rotation (505) which is inclined relative to the cutting plane (502) so that the cutting plane (502) is movable by translation along the longitudinal axis (402A).

2. The apparatus according to claim 1, comprising a gluing unit (301A) configured to place glue on at least one of either the inside face of the outer strip of paper or the outside face of the inner strip of paper.

3. The apparatus according to claim 2, wherein the gluing unit (301A) is positioned along an unwinding path of the outer paper strip (8A) and is configured to place glue on the inside face of the outer paper strip, the inner strip (7A) being without glue upstream of the mandrel (401A).

4. The apparatus according to claim 2 or 3, comprising at least one scraping element (302A) acting on the inside face of the outer strip (8A) and positioned upstream of the gluing unit (301A).

5. The apparatus according to any one of the preceding claims, comprising at least one outer strain-relieving element (304A) and one inner strain-relieving element (303A), acting at least on the outer strip (8A) of paper and inner strip (7A) of paper, respectively.

6. The apparatus according to any one of the preceding claims, comprising a first and a second pulley (404A, 405A) rotating about respective axes of rotation which are parallel to each other and perpendicular to the longitudinal axis (402A) of the mandrel (401A), wherein the belt (403A) is looped around the first and second pulleys (404A, 405A) to define a forward-moving section (406A) and a return section (407A) which cross each other, wherein the forward-moving section (406A) is wrapped around the mandrel (401A) at an inclination angle of between 30 and 60 degrees and has a first stretch (408A), connecting the first pulley (404A) and the mandrel (401A), defining a ninety degree twist in a first direction, and a second stretch (409A), connecting the second pulley (405A) and the mandrel (401A), defining a ninety degree twist in a second direction, opposite to or the same as the first direction.

7. The apparatus according to any one of the preceding claims, comprising an outfeed station (6), located downstream of the cutting station (5) and configured to receive the pieces (200) of tubular rod (2A), wherein the outfeed station (6) comprises a drum (601) rotating about an axis (602) which is parallel to the longitudinal axis (402A) of the mandrel (401A) and which has a plurality of equispaced housings (603) on the periphery of the drum (601), wherein each housing (603) of the plurality has a width, measured tangentially to the drum (601), which decreases in the feed direction of the tubular rod (2A).

8. The apparatus according to any of the foregoing claims, wherein:

the inner strip (7A) wrapped around the mandrel (401A) has a predetermined spacing (P) and coils juxtaposed with each other without overlapping,

the outer strip (8A) wrapped around the mandrel has said predetermined spacing (P) and coils juxtaposed with each other without overlapping, wherein the coils of the outer strip (8A) are longitudinally offset relative to the coils of the inner strip (7A).

9. The apparatus according to any one of the preceding claims, comprising a heater operating in a space located downstream of the gluing unit (301A) and upstream of the cutting station (5).

10. The apparatus according to any one of the preceding claims, comprising:

- a second mandrel (401B), a second inner strip (7A) of paper, a second outer strip (8B) of paper and a second power-driven belt (403B), in addition to the mandrel (401A), the inner strip (7A) of paper, the outer strip (8A) of paper and the belt (403A), which define a first mandrel, a first inner strip of paper, a first outer strip of paper and a first power-driven belt, respectively, wherein the second inner and outer strips (7B, 8B) are wrapped around the second mandrel (401B) and the second belt (403B) operates on the second outer strip (8B) to form a second tubular rod (2B),

- an outer roll (307) of an outer web (11) and an inner roll (306) of an inner web (10);

- at least one cutting unit (308, 309) configured to cut the inner web (10) and the outer web (11) longitudinally, to generate respective pairs of a first and a second half-web, wherein the first and second half webs obtained from the inner web (10) are wrapped around the first and second mandrels (401A, 401B), respectively, to define the first and second inner strips (7A, 7B), respectively, and the first and second half webs obtained from the outer web (11) are wrapped around the first and second mandrels (401A, 401B), respectively, to define the first and second outer strips (8A, 8B), respectively.

11. The apparatus according to claim 10, comprising, for each inner web (10) and outer web (11):

- a first unwinding unit (3101, 310E) having a first power-driven feed roller located downstream of the at least one cutting unit and coupled to the respective first paper strip (7A, 8A);

- a first adjusting unit (3131, 313E), having a first system of reciprocally movable transmission rollers for lengthening and shortening the path of the first paper strip (7A, 8A);

- a second unwinding unit (3111, 311E) having a second power-driven feed roller located downstream of the at least one cutting unit and coupled to the respective second paper strip (7B, 8B);

- a second adjusting unit (3141, 314E), having a second system of reciprocally movable transmission rollers for lengthening and shortening the path of the second paper strip (7B, 8B);

- a third unwinding unit (3121, 312E) having a third power-driven feed roller located upstream of the at least one cutting unit and coupled to the respective web (10, 11);

a third adjusting unit (3151, 315E), having a third system of reciprocally movable transmission rollers for lengthening and shortening the path of the respective web (10, 11).

12. The apparatus according to claim 10 or 11, wherein the second mandrel (401B) is oriented along a longitudinal axis (402B) parallel to the longitudinal axis of the first mandrel (401A) and the cutting station (5) is configured to cut pieces (200) also of the second tubular rod (2B).

13. A method for making semifinished products forming part of smokers' articles, comprising the following steps:

- preparing an inner strip (7A) of paper and wrapping the same helically around a stationary mandrel (401A) which is elongate along a longitudinal axis (402A);

- preparing an outer strip (8A) of paper which is operatively wrapped helically around the inner strip (7A), with an inside face of the outer strip in contact with an outside face of the inner strip;

- gluing at least one of either the inside face of the outer strip (8A) or the outside face of the inner strip (7A);

- moving a belt (403A) which is helically wrapped around the outer strip (8A) in order to impart to the inner and outer strips (7A, 8A) a movement of rotation about the longitudinal axis (402A) of the mandrel (401A) and of translation along the axis (402A) in a direction of feed, so as to generate a tubular rod (2A) fed continuously along the longitudinal axis (402A) in the feed direction;

- cutting the tubular rod (2A) downstream of the mandrel (401A) by means of a blade (501),

the method being characterized in that the blade (501) is oriented in a cutting plane (502) perpendicular to the longitudinal axis (402A) and is movable along a circular trajectory, around an axis of rotation (505) which is inclined relative to the cutting plane (502), so that the cutting plane (502) is movable by translation along the longitudinal axis (402A) and the speed of the blade (501), while it cuts the rod (2A), has a component of translation along the longitudinal axis (402A) in the feed direction.

14. The method according to claim 13, comprising the following steps:

- preparing a second mandrel (401B), a second inner strip (7B) of paper, a second outer strip (8B) of paper and a second belt (403B), in addition to the mandrel (401A), the inner strip (7A), the outer strip (8A) and the belt (403A), which define a first mandrel, a first inner strip, a first outer strip, a first power-driven belt, respectively, wherein the second inner and outer strips (7B, 8B) are wrapped around the second mandrel (401B) and the second belt (403B) helically feeds the second outer strip (8B) glued to the second inner strip (7B) to form a second tubular rod (2B) which is fed out continuously from the second mandrel (401B);

- preparing an outer roll (307) of an outer web (11) and an inner roll (306) of an inner web (10);

- longitudinally cutting the inner web (10) and the outer web (11) to generate respective pairs of a first and a second half-web, wherein the first and second half webs obtained from the inner web (10) define the first and second inner strips (7A, 7B), respectively, and the first and second half webs obtained from the outer web (11) define the first and second outer strips (8A, 8B).

15. The method according to claim 14, comprising, for each inner web (10) and outer web (11), the following steps:

- unwinding the first strip (7A, 8A) of paper and adjusting the length of a path defined by the first strip (7A, 8A), downstream of the cut of the web (10, 11) itself, by means of a first unwinding unit (3101, 310E) and a first adjusting unit (3131, 313E), respectively;

- unwinding the second strip (7B, 8B) and adjusting the length of a path defined by the second strip (7B, 8B), downstream of the cut of the web itself, by means of a second unwinding unit (3111, 311E) and a second adjusting unit (3141, 314E), respectively;

- unwinding the web (10, 11) and adjusting the length of a path defined by the web, upstream of the cut of the web itself, by means of a third unwinding unit (3121, 312E) and a third adjusting unit (3151, 315E), respectively;

- automatically controlling the first, second and third unwinding units (3101, 310E, 3111, 311E, 3121, 312E) and adjusting units (3131, 313E, 3141, 314E, 3151, 315E) as a function of the detected tension of the first and second strips and of the web.

Ansprüche

1. Vorrichtung (1) zur Herstellung von Halbzeugen als Teil von Raucherartikeln, umfassend:

- einen stationären Dorn (401A), der sich entlang einer Längsachse (402A) verlängert;

- einen inneren Streifen (7A) Papier, der betriebswirksam spiralförmig um den Dorn (401A) gewickelt ist;
mindestens einen äußeren Streifen (8A) Papier, der betriebswirksam spiralförmig um den inneren Streifen (7A) gewickelt ist, wobei eine Innenseite des äußeren Streifens mit einer Außenseite des inneren Streifens in Kontakt steht;

- einen kraftbetriebenen Riemen (403A), der an dem äußeren Streifen (8A) arbeitet, um dem inneren und äußeren Streifen (7A, 8A) eine Drehbewegung um die Längsachse (402A) des Dorns und eine Translationsbewegung entlang der Achse in einer Zuführrichtung zu verleihen, wobei der Riemen (403A) mit dem äußeren Streifen (8A) auf einer Kontaktfläche in Kontakt steht, die spiralförmig relativ zur Längsachse (402A) angeordnet ist;

- eine Schneidestation (5), die stromabwärts des Dorns (401A) angeordnet ist, um Stücke (200) eines rohrförmigen Stabes (2A) Papier zu schneiden, der aus dem Dorn (401A) herauskommt und aus dem inneren und äußeren Streifen (7A, 8A) Papier besteht, die aneinander geklebt sind, wobei die Schneidestation (5) eine Klinge (501) zum Abfangen und Schneiden des Stabs (2A) umfasst, dadurch gekennzeichnet, dass die Klinge (501) in einer Schnittebene (502) senkrecht zur Längsachse (402A) angeordnet ist und entlang einer Kreisbahn um eine Drehachse (505) beweglich ist, die relativ zur Schnittebene (502) geneigt ist, so dass die Schnittebene (502) durch Translation entlang der Längsachse (402A) beweglich ist.

2. Vorrichtung nach Anspruch 1, umfassend eine Klebeeinheit (301A), die konfiguriert ist, um Klebstoff auf mindestens entweder die Innenseite des äußeren Streifens Papier oder die Außenseite des inneren Streifens Papier aufzubringen.

3. Vorrichtung nach Anspruch 2, wobei die Klebeeinheit (301A) entlang eines Abwickelweges des äußeren Papierstreifens (8A) positioniert und konfiguriert ist, um Klebstoff auf die Innenseite des äußeren Papierstreifens aufzubringen, wobei der innere Streifen (7A) stromaufwärts des Dorns (401A) ohne Klebstoff ist.

4. Vorrichtung nach Anspruch 2 oder 3, umfassend mindestens ein Abstreifelement (302A), das auf die Innenseite des äußeren Streifens (8A) wirkt und stromaufwärts der Klebeeinheit (301A) positioniert ist.

5. Vorrichtung nach einem der vorhergehenden Ansprüche, umfassend mindestens ein äußeres Zugentlastungselement (304A) und ein inneres Zugentlastungselement (303A), die jeweils mindestens auf den äußeren Streifen (8A) Papier und den inneren Streifen (7A) Papier wirken.

6. Vorrichtung nach einem der vorhergehenden Ansprüche, umfassend eine erste und eine zweite Riemenscheibe (404A, 405A), die sich um jeweilige Drehachsen drehen, die parallel zueinander und senkrecht zur Längsachse (402A) des Dorns (401A) sind, wobei der Riemen (403A) um die erste und die zweite Riemenscheibe (404A, 405A) geschlungen ist, um einen sich vorwärts bewegenden Abschnitt (406A) und einen Rückwärtsabschnitt (407A) zu definieren, die sich einander kreuzen, wobei der sich vorwärts bewegende Abschnitt (406A) in einem Neigungswinkel zwischen 30 und 60 Grad um den Dorn (401A) gewickelt ist und ein erstes Teilstück (408A), das die erste Riemenscheibe (404A) und den Dorn (401A) verbindet und eine Verdrehung von neunzig Grad in einer ersten Richtung definiert, und ein zweites Teilstück (409A) aufweist, das die zweite Riemenscheibe (405A) und den Dorn (401A) verbindet und eine Verdrehung von neunzig Grad in einer zweiten Richtung definiert, die der ersten Richtung entgegengesetzt oder dieser gleich ist.

7. Vorrichtung nach einem der vorhergehenden Ansprüche, umfassend eine Ausgabestation (6), die stromabwärts der Schneidestation (5) angeordnet und konfiguriert ist, um die Stücke (200) des rohrförmigen Stabs (2A) aufzunehmen, wobei die Ausgabestation (6) eine Trommel (601) umfasst, die sich um eine Achse (602) dreht, die parallel zur Längsachse (402A) des Dorns (401A) ist und die eine Vielzahl an gleich beabstandeten Gehäusen (603) am Umfang der Trommel (601) aufweist, wobei ein jedes Gehäuse (603) der Vielzahl eine tangential zur Trommel (601) gemessene Breite aufweist, die in der Zuführrichtung des rohrförmigen Stabes (2A) abnimmt.

8. Vorrichtung nach einem der vorhergehenden Ansprüche, wobei:

der innere Streifen (7A), der um den Dorn (401A) gewickelt ist, einen vorbestimmten Abstand (P) und Spulen aufweist, die ohne Überlappung nebeneinander angeordnet sind,

der äußere Streifen (8A), der um den Dorn gewickelt ist, den vorbestimmten Abstand (P) und die Spulen aufweist, die ohne Überlappung nebeneinander angeordnet sind, wobei die Spulen des äußeren Streifens (8A) in Längsrichtung relativ zu den Spulen des inneren Streifens (7A) versetzt sind.

9. Vorrichtung nach einem der vorhergehenden Ansprüche, umfassend ein Heizgerät, das in einem Raum arbeitet, der sich stromabwärts der Klebeeinheit (301A) und stromaufwärts der Schneidestation (5) befindet.

10. Vorrichtung nach einem der vorhergehenden Ansprüche, umfassend:

- einen zweiten Dorn (401B), einen zweiten inneren Streifen (7A) Papier, einen zweiten äußeren Streifen (8B) Papier und einen zweiten kraftbetriebenen Riemen (403B) zusätzlich zu dem Dorn (401A), dem inneren Streifen (7A) Papier, dem äußeren Streifen (8A) Papier und dem Riemen (403A), die jeweils einen ersten Dorn, einen ersten inneren Streifen Papier, einen ersten äußeren Streifen Papier und einen ersten kraftbetriebenen Riemen definieren, wobei der zweite innere und äußere Streifen (7B, 8B) um den zweiten Dorn (401B) gewickelt sind und der zweite Riemen (403B) auf den zweiten äußeren Streifen (8B) wirkt, um einen zweiten rohrförmigen Stab (2B) zu bilden,

- eine äußere Rolle (307) einer äußeren Bahn (11) und eine innere Rolle (306) einer inneren Bahn (10);

- mindestens eine Schneideinheit (308, 309), die konfiguriert ist, um die innere Bahn (10) und die äußere Bahn (11) in Längsrichtung zu schneiden, um jeweilige Paare einer ersten und einer zweiten Halbbahn zu erzeugen, wobei die erste und zweite Halbbahn, die von der inneren Bahn (10) erhalten wurden, um jeweils den ersten und zweiten Dorn (401A, 401B) gewickelt sind, um jeweils den ersten und zweiten inneren Streifen (7A, 7B) zu definieren, und die erste und zweite Halbbahn, die von der äußeren Bahn (11) erhalten wurden, um jeweils den ersten und zweiten Dorn (401A, 401B) gewickelt sind, um jeweils den ersten und zweiten äußeren Streifen (8A, 8B) zu definieren.

11. Vorrichtung nach Anspruch 10, umfassend für eine jede innere Bahn (10) und äußere Bahn (11):

- eine erste Abwickeleinheit (310I, 310E) mit einer ersten kraftbetriebenen Zuführwalze, die stromabwärts der mindestens einen Schneideinheit angeordnet und mit dem jeweiligen ersten Papierstreifen (7A, 8A) gekoppelt ist;

- eine erste Einstelleinheit (313I, 313E) mit einem ersten System von wechselseitig beweglichen Übertragungswalzen zum Verlängern und Verkürzen des Weges des ersten Papierstreifens (7A, 8A);

- eine zweite Abwickeleinheit (311I, 311E) mit einer zweiten kraftbetriebenen Zuführwalze, die stromabwärts der mindestens einen Schneideinheit angeordnet und mit dem jeweiligen zweiten Papierstreifen (7B, 8B) gekoppelt ist;

- eine zweite Einstelleinheit (314I, 314E) mit einem zweiten System von wechselseitig beweglichen Übertragungswalzen zum Verlängern und Verkürzen des Weges des zweiten Papierstreifens (7B, 8B);

- eine dritte Abwickeleinheit (312I, 312E) mit einer dritten kraftbetriebenen Zuführwalze, die stromaufwärts der mindestens einen Schneideinheit angeordnet und mit der jeweiligen Bahn (10, 11) gekoppelt ist;

eine dritte Einstelleinheit (315I, 315E) mit einem dritten System von wechselseitig beweglichen Übertragungswalzen zum Verlängern und Verkürzen des Weges der jeweiligen Bahn (10, 11).

12. Vorrichtung nach Anspruch 10 oder 11, wobei der zweite Dorn (401B) entlang einer Längsachse (402B) parallel zur Längsachse des ersten Dorns (401A) ausgerichtet ist und die Schneidestation (5) konfiguriert ist, um Stücke (200) auch des zweiten rohrförmigen Stabes (2B) zu schneiden.

13. Verfahren zur Herstellung von Halbzeugen als Teil von Raucherartikeln, umfassend die folgenden Schritte:

- Vorbereiten eines inneren Streifens (7A) Papier und Wickeln desselben spiralförmig um einen stationären Dorn (401A), der sich entlang einer Längsachse (402A) verlängert;

- Vorbereiten eines äußeren Streifens (8A) Papier, der betriebswirksam spiralförmig um den inneren Streifen (7A) gewickelt ist, wobei eine Innenseite des äußeren Streifens mit einer Außenseite des inneren Streifens in Kontakt steht;

- Kleben mindestens entweder der Innenseite des äußeren Streifens (8A) oder der Außenseite des inneren Streifens (7A);

- Bewegen eines Riemens (403A), der spiralförmig um den äußeren Streifen (8A) gewickelt ist, um dem inneren und äußeren Streifen (7A, 8A) eine Drehbewegung um die Längsachse (402A) des Dorns (401A) und eine Translationsbewegung entlang der Achse (402A) in einer Zuführrichtung zu verleihen, um einen rohrförmigen Stab (2A) zu erzeugen, der kontinuierlich entlang der Längsachse (402A) in Zuführrichtung zugeführt wird;

- Schneiden des rohrförmigen Stabs (2A) stromabwärts des Dorns (401A) mittels einer Klinge (501),

wobei das Verfahren dadurch gekennzeichnet ist, dass die Klinge (501) in einer Schnittebene (502) senkrecht zur Längsachse (402A) ausgerichtet ist und entlang einer Kreisbahn um eine Drehachse (505) beweglich ist, die relativ zur Schnittebene (502) geneigt ist, so dass die Schnittebene (502) durch Translation entlang der Längsachse (402A) beweglich ist und die Geschwindigkeit der Klinge (501), während sie den Stab (2A) schneidet, eine Translationskomponente entlang der Längsachse (402A) in Zuführrichtung aufweist.

14. Verfahren nach Anspruch 13, umfassend die folgenden Schritte:

- Vorbereiten eines zweiten Dorns (401B), eines zweiten inneren Streifens (7B) Papier, eines zweiten äußeren Streifens (8B) Papier und eines zweiten Riemens (403B) zusätzlich zu dem Dorn (401A), dem inneren Streifen (7A), dem äußeren Streifen (8A) und dem Riemen (403A), die jeweils einen ersten Dorn, einen ersten inneren Streifen, einen ersten äußeren Streifen und einen ersten kraftbetriebenen Riemen definieren, wobei der zweite innere und äußere Streifen (7B, 8B) um den zweiten Dorn (401B) gewickelt sind und der zweite Riemen (403B) den zweiten äußeren Streifen (8B), der mit dem zweiten inneren Streifen (7B) verklebt ist, spiralförmig zuführt, um einen zweiten rohrförmigen Stab (2B) zu bilden, der kontinuierlich vom zweiten Dorn (401B) herausgeführt wird;

- Vorbereiten einer äußeren Rolle (307) einer äußeren Bahn (11) und einer inneren Rolle (306) einer inneren Bahn (10);

- Längsschneiden der inneren Bahn (10) und der äußeren Bahn (11), um jeweilige Paare einer ersten und einer zweiten Halbbahn zu erzeugen, wobei die erste und zweite Halbbahn, die von der inneren Bahn (10) erhalten wurden, jeweils den ersten und zweiten inneren Streifen (7A, 7B) definieren und die erste und zweite Halbbahn, die von der äußeren Bahn (11) erhalten wurden, den ersten und zweiten äußeren Streifen (8A, 8B) definieren.

15. Verfahren nach Anspruch 14, umfassend für eine jede innere Bahn (10) und äußere Bahn (11) die folgenden Schritte:

- Abwickeln des ersten Streifens (7A, 8A) Papier und Einstellen der Länge eines durch den ersten Streifen (7A, 8A) definierten Weges stromabwärts des Schnittes der Bahn (10, 11) selbst jeweils mittels einer ersten Abwickeleinheit (310I, 310E) und einer ersten Einstelleinheit (313I, 313E);

- Abwickeln des zweiten Streifens (7B, 8B) und Einstellen der Länge eines durch den zweiten Streifen (7B, 8B) definierten Weges stromabwärts des Schnittes der Bahn selbst jeweils mittels einer zweiten Abwickeleinheit (311I, 311E) und einer zweiten Einstelleinheit (314I, 314E) ;

- Abwickeln der Bahn (10, 11) und Einstellen der Länge eines durch die Bahn definierten Weges stromaufwärts des Schnittes der Bahn selbst jeweils mittels einer dritten Abwickeleinheit (312I, 312E) und einer dritten Einstelleinheit (315I, 315E);

- automatisches Steuern der ersten, zweiten und dritten Abwickeleinheit (310I, 310E, 311I, 311E, 312I, 312E) und Einstelleinheit (313I, 313E, 314I, 314E, 315I, 315E) als Funktion der erfassten Spannung des ersten und zweiten Streifens und der Bahn.

Revendications

1. Appareil (1) de fabrication de produits semi-finis destinés à faire partie d'articles pour fumeur, comprenant :

- un mandrin fixe (401A) allongé le long d'un axe longitudinal (402A) ;

- un ruban intérieur (7A) de papier opérationnellement enroulé de manière hélicoïdale autour du mandrin (401A) ; au moins un ruban extérieur (8A) de papier opérationnellement enroulé de manière hélicoïdale autour du ruban intérieur (7A), avec une face intérieure du ruban extérieur en contact avec une face extérieure du ruban intérieur;

- une courroie motorisée (403A) agissant sur le ruban extérieur (8A) pour conférer aux rubans intérieur et extérieur (7A, 8A) un mouvement de rotation autour de l'axe longitudinal (402A) du mandrin et de translation le long de l'axe dans une direction d'alimentation, dans lequel la courroie (403A) est en contact avec le ruban extérieur (8A) sur une surface de contact disposée de manière hélicoïdale par rapport à l'axe longitudinal (402A) ;

- un poste de coupe (5) positionné en aval du mandrin (401A) pour couper des morceaux (200) d'une tige tubulaire (2A) de papier sortant du mandrin (401A) et constituée par les rubans intérieur et extérieur (7A, 8A) de papier collés l'un à l'autre, dans lequel le poste de coupe (5) comprend une lame (501) pour intercepter et couper la tige (2A), caractérisé en ce que la lame (501) est disposée dans un plan de coupe (502) perpendiculaire à l'axe longitudinal (402A) et est mobile le long d'une trajectoire circulaire autour d'un axe de rotation (505) qui est incliné par rapport au plan de coupe (502) de sorte que le plan de coupe (502) est mobile par translation le long de l'axe longitudinal (402A).

2. Appareil selon la revendication 1, comprenant une unité de collage (301A) configurée pour placer de la colle sur au moins une entre la face intérieure du ruban extérieur de papier et la face extérieure du ruban intérieur de papier.

3. Appareil selon la revendication 2, dans lequel l'unité de collage (301A) est positionnée le long d'un trajet de déroulement du ruban extérieur (8A) de papier et est configurée pour placer de la colle sur la face intérieure du ruban extérieur de papier, le ruban intérieur (7A) étant sans colle en amont du mandrin (401A).

4. Appareil selon la revendication 2 ou 3, comprenant au moins un élément racleur (302A) agissant sur la face intérieure du ruban extérieur (8A) et placé en amont de l'unité de collage (301A).

5. Appareil selon l'une quelconque des revendications précédentes, comprenant au moins un élément extérieur de soulagement des contraintes (304A) et un élément intérieur de soulagement des contraintes (303A), agissant au moins sur le ruban extérieur (8A) de papier et le ruban intérieur (7A) de papier, respectivement.

6. Appareil selon l'une quelconque des revendications précédentes, comprenant une première et une deuxième poulie (404A, 405A) tournant autour d'axes de rotation respectifs qui sont parallèles l'un à l'autre et perpendiculaires à l'axe longitudinal (402A) du mandrin (401A), dans lequel la courroie (403A) est enroulée autour des première et deuxième poulies (404A, 405A) pour définir une section se déplaçant vers l'avant (406A) et une section de retour (407A) qui se croisent, dans lequel la section se déplaçant vers l'avant (406A) est enroulée autour du mandrin (401A) avec un angle d'inclinaison compris entre 30 et 60 degrés et comporte un premier tronçon (408A), reliant la première poulie (404A) et le mandrin (401A), définissant une torsion de quatre-vingt-dix degrés dans une première direction, et un deuxième tronçon (409A), reliant la deuxième poulie (405A) et le mandrin (401A), définissant une torsion de quatre-vingt-dix degrés dans une deuxième direction, opposée ou identique à la première direction.

7. Appareil selon l'une quelconque des revendications précédentes, comprenant un poste d'expulsion (6), situé en aval du poste de coupe (5) et configuré pour recevoir les morceaux (200) de tige tubulaire (2A), dans lequel le poste d'expulsion (6) comprend un tambour (601) tournant autour d'un axe (602) qui est parallèle à l'axe longitudinal (402A) du mandrin (401A) et qui comporte une pluralité de logements équidistants (603) sur la périphérie du tambour (601), dans lequel chaque logement (603) de la pluralité a une largeur, mesurée tangentiellement au tambour (601), qui diminue dans la direction d'alimentation de la tige tubulaire (2A).

8. Appareil selon l'une quelconque des revendications précédentes, dans lequel :

le ruban intérieur (7A) enroulé autour du mandrin (401A) a un espacement prédéterminé (P) et des bobines juxtaposées les unes aux autres sans se chevaucher,

le ruban extérieur (8A) enroulé autour du mandrin a ledit espacement prédéterminé (P) et des bobines juxtaposées les unes aux autres sans se chevaucher, dans lequel les bobines du ruban extérieur (8A) sont décalées longitudinalement par rapport aux bobines du ruban intérieur (7A).

9. Appareil selon l'une quelconque des revendications précédentes, comprenant un réchauffeur fonctionnant dans un espace situé en aval de l'unité de collage (301A) et en amont du poste de découpe (5).

10. Appareil selon l'une quelconque des revendications précédentes, comprenant :

- un deuxième mandrin (401B), un deuxième ruban intérieur (7A) de papier, un deuxième ruban extérieur (8B) de papier et une deuxième courroie motorisée (403B), en plus du mandrin (401A), du ruban intérieur (7A) de papier, du ruban extérieur (8A) de papier et de la courroie (403A), qui définissent un premier mandrin, un premier ruban intérieur de papier, un premier ruban extérieur de papier et une première courroie motorisée, respectivement, dans lequel les deuxièmes rubans intérieur et extérieur (7B, 8B) sont enroulés autour du deuxième mandrin (401B) et la deuxième courroie (403B) fonctionne sur le deuxième ruban extérieur (8B) pour former une deuxième tige tubulaire (2B),

- un rouleau extérieur (307) d'une bande extérieure (11) et un rouleau intérieur (306) d'une bande intérieure (10) ;

- au moins une unité de coupe (308, 309) configurée pour couper la bande intérieure (10) et la bande extérieure (11) longitudinalement, pour générer des paires respectives d'une première et d'une deuxième demi-bande, dans lequel les première et deuxième demi-bandes obtenues à partir de la bande intérieure (10) sont enroulées autour des premier et deuxième mandrins (401A, 401B), respectivement, pour définir les premier et deuxième rubans intérieurs (7A, 7B), respectivement, et les première et deuxième demi-bandes obtenues à partir de la bande extérieure (11) sont enroulées autour des premier et deuxième mandrins (401A, 401B), respectivement, pour définir les premier et deuxième rubans extérieurs (8A, 8B), respectivement.

11. Appareil selon la revendication 10, comprenant, pour chaque bande intérieure (10) et bande extérieure (11) :

- une première unité de déroulement (310I, 310E) ayant un premier rouleau d'alimentation motorisé situé en aval de l'au moins une unité de coupe et couplé au premier ruban (7A, 8A) de papier respective;

- une première unité de réglage (313I, 313E), ayant un premier système de rouleaux de transmission mobiles réciproquement pour allonger et raccourcir le trajet du premier ruban (7A, 8A) de papier;

- une deuxième unité de déroulement (311I, 311E) comportant un deuxième rouleau d'alimentation motorisé situé en aval de l'au moins une unité de coupe et couplé au deuxième ruban (7B, 8B) de papier respective;

- une deuxième unité de réglage (314I, 314E), comportant un deuxième système de rouleaux de transmission mobiles réciproquement pour allonger et raccourcir le trajet du deuxième ruban (7B, 8B) de papier;

- une troisième unité de déroulement (312I, 312E) ayant un troisième rouleau d'alimentation motorisé situé en amont de l'au moins une unité de coupe et couplé à la bande respective (10, 11) ;

une troisième unité de réglage (315I, 315E), ayant un troisième système de rouleaux de transmission mobiles réciproquement pour allonger et raccourcir le trajet de la bande respective (10, 11).

12. Appareil selon la revendication 10 ou 11, dans lequel le deuxième mandrin (401B) est orienté le long d'un axe longitudinal (402B) parallèle à l'axe longitudinal du premier mandrin (401A) et le poste de coupe (5) est configuré pour couper des morceaux (200) également de la deuxième tige tubulaire (2B).

13. Procédé de fabrication de produits semi-finis faisant partie d'articles pour fumeur, comprenant les éléments suivants :

- préparer un ruban intérieur (7A) de papier et l'enrouler de manière hélicoïdale autour d'un mandrin fixe (401A) qui est allongé le long d'un axe longitudinal (402A) ;

- préparer un ruban extérieur (8A) de papier qui est opérationnellement enroulé de manière hélicoïdale autour du ruban intérieur (7A), avec une face intérieure du ruban extérieur en contact avec la face extérieure du ruban intérieur;

- coller au moins une entre la face intérieure du ruban extérieur (8A) et la face extérieure du ruban intérieur (7A) ;

- déplacer une courroie (403A) qui s'enroule de manière hélicoïdale autour du ruban extérieur (8A) afin de conférer aux rubans intérieur et extérieur (7A, 8A) un mouvement de rotation autour de l'axe longitudinal (402A) du mandrin (401A) et de translation le long de l'axe (402A) dans une direction d'alimentation, de manière à générer une tige tubulaire (2A) alimentée en continu le long de l'axe longitudinal (402A) dans la direction d'alimentation;

- couper la tige tubulaire (2A) en aval du mandrin (401A) au moyen d'une lame (501),

le procédé étant caractérisé en ce que la lame (501) est orientée dans un plan de coupe (502) perpendiculaire à l'axe longitudinal (402A) et est mobile selon une trajectoire circulaire, autour d'un axe de rotation (505) qui est incliné par rapport au plan de coupe (502), de sorte que le plan de coupe (502) est mobile par translation le long de l'axe longitudinal (402A) et la vitesse de la lame (501), lorsqu'elle coupe la tige (2A), a une composante de translation le long de l'axe longitudinal (402A) dans la direction d'alimentation.

14. Procédé selon la revendication 13, comprenant les étapes suivantes :

- préparer un deuxième mandrin (401B), un deuxième ruban intérieur (7B) de papier, un deuxième ruban extérieur (8B) de papier et une deuxième courroie (403B), en plus du mandrin (401A), du ruban intérieur (7A), du ruban extérieur (8A) et de la courroie (403A), qui définissent un premier mandrin, un premier ruban intérieur, un premier ruban extérieur, une première courroie motorisée, respectivement, dans lequel les deuxièmes rubans intérieur et extérieur (7B, 8B) sont enroulés autour du deuxième mandrin (401B) et la deuxième courroie (403B) alimente de manière hélicoïdale le deuxième ruban extérieur (8B) collé au deuxième ruban intérieur (7B) pour former une deuxième tige tubulaire (2B) qui est expulsée en continu du deuxième mandrin (401B) ;

- préparer un rouleau extérieur (307) d'une bande extérieure (11) et un rouleau intérieur (306) d'une bande intérieure (10) ;

- découper longitudinalement la bande intérieure (10) et la bande extérieure (11) pour générer des paires respectives d'une première et d'une deuxième demi-bande, dans lequel les première et deuxième demi-bandes obtenues à partir de la bande intérieure (10) définissent les premier et deuxième rubans intérieurs (7A, 7B), respectivement, et les première et deuxième demi-bandes obtenues à partir de la bande extérieure (11) définissent les premier et deuxième rubans extérieurs (8A, 8B).

15. Procédé selon la revendication 14, comprenant, pour chaque bande intérieure (10) et bande extérieure (11), les étapes suivantes:

- dérouler le premier ruban (7A, 8A) de papier et régler la longueur d'un trajet défini par le premier ruban (7A, 8A), en aval de la coupe de la bande (10, 11) elle-même, au moyen d'une première unité de déroulement (310I, 310E) et d'une première unité de réglage (313I, 313E), respectivement;

- dérouler le deuxième ruban (7B, 8B) et régler la longueur d'un trajet défini par le deuxième ruban (7B, 8B), en aval de la coupe de la bande elle-même, au moyen d'une deuxième unité de déroulement (311I, 311E) et d'une deuxième unité de réglage (314I, 314E), respectivement;

- dérouler la bande (10, 11) et régler la longueur d'un trajet défini par la bande, en amont de la coupe de la bande elle-même, au moyen d'une troisième unité de déroulement (312I, 312E) et d'une troisième unité de réglage (315I, 315E), respectivement;

- contrôler automatiquement les première, deuxième et troisième unités de déroulement (310I, 310E, 311I, 311E, 312I, 312E) et unités de réglage (313I, 313E, 314I, 314E, 315I, 315E) en fonction de la tension détectée des premier et deuxième rubans et de la bande.

Drawing