EP1978833B1 - Deflecting device for a continuous filter tow, method for conveying and deflecting at least one continuous filter tow, and device for the production of cigarette filters - Google Patents

Abstract

The invention relates to a deflecting device for conveying and deflecting at least one continuous filter tow (13). Said deflecting device can be coupled to a forming part (2a, 2b), especially a feeding system of a machine used for producing filter rods. The inventive deflecting device is characterized by a conveying mechanism (40) for pneumatically conveying the at least one continuous filter tow (13) as well as a deflecting apparatus (50) which cooperates with the conveying mechanism (40) so as to deflect the continuous filter tow (13) in a substantially pneumatically driven manner.

Description

The invention relates to a deflection device for conveying and deflecting at least one filter tow strand. This device can be coupled with a format part, in particular with an intake system of a machine for the production of filter rods. Moreover, the invention relates to a machine comprising such a deflection device and a method for conveying and deflecting at least one filter tow.

A deflection device of the type mentioned is, for example, from the WO 2005/058 079 A1 known. This deflection device is used in double-strand machines, which comprise two format sections for forming continuous filter rods and a filter material supply line for each format section. The supply lines receive the filter material from a conveyor line which extends between an inlet region of the supply lines and a storage area of two filter material bales. Of the bales each Lunten be unwound, which are fed along the conveyor line to a blower, which is provided in the inlet area to pull the two Lunten transversely in two strips of filter material. After the fan, the two strips are blown along respective feeds by a pressing device, then by an expander, in the air in the strips to increase their volume, and finally conveyed by a conditioning device where chemical substances are added to the strip to give the filter material flavor and formability.

Each feeder is connected to the format section by a diverter which serves to convert and stabilize the strips into strands of filter material. The diverter receives a strip from the feeder and conveys this, in the shape of a uniform strand, on a strip of previously rubberized paper in the format section. The diverter unit typically includes a hopper for each feeder into which the strip is inserted and compacted, thereby forming the filter material strand. In order to improve the homogeneity of the filter material in the strand, air can be blown into the hopper, such as in the US 4,522,616 A1 described.

The paper strip is wound in the format section transversally around the strand, whereby a continuous filter rod is formed. At the outlet of the format sections, a control unit controls the density of the filter rods. A cutting head cuts the bars into individual filter sections.

It is known to reduce the distance between the two filter material strands in the deflection unit. For example, in the WO 2005/058 079 A1 the distance between the two filter material strands is reduced by using two feed hoppers with two curved bends for each filter material strand.

The reduction of the distance between the two strands in the deflection unit of the machine according to WO 2005/058 079 A1 is effected by two pulleys, which have a V-shaped cross-section. The two deflection rollers interact with the curvature arcs of the two inlet funnels and receive the filter tow strand from two transport rollers. The filter material strand is therefore fed mechanically into the two inlet funnel.

Filter rods made on known filter rod machines with a deflection unit described above have insufficient homogeneity.

The invention has for its object to further develop the aforementioned deflection such that filter rods can be produced with improved homogeneity. Moreover, the device with comparatively be easy to implement at a low cost. Another object of the invention is to provide a machine with such a deflection device and a method for conveying and deflecting at least one filter tow.

According to the invention, the above-mentioned object is achieved by a machine for producing cigarette filters according to independent claim 1.

Further improvements and structural details of the invention are specified in the subclaims.

An essential aspect of the invention is the provision of a transport device for pneumatically conveying the at least one filter strand and a deflection device which cooperates with the transport device for pneumatically driven deflection of the filter tow strand.

This means that the conveying direction of the strand is changed, wherein the driving force, at least in the region where the conveying direction is changed, that is pneumatically applied in the region of the deflection.

Without wishing to be bound by the theory that follows, it is believed that the combination of pneumatic transport with strand deflection results in increased fluidization of the material, resulting in a very homogeneous filter material. In particular, the draw resistance and draw resistance spread of a filter rod are significantly improved, which is obtainable by a filter rod machine with the inventive deflection device. Moreover, the deflection device according to the invention can be realized cost-effectively, so that the total cost of the filter rod machine can be reduced. The inventive deflection device can be used in a simple manner in known filter rod machines, wherein only the existing deflection unit of such a machine is replaced by the deflection device according to the invention.

In contrast to the deflection device according to the invention, the known deflection device according to WO 2005/058 079 A1 designed to feed the filter tow line mechanically into the format section of the machine. The known deflection device couples to a mechanical conveyor with a deflection. This filter rod machine is therefore unable to produce a filter material which is comparable in terms of homogeneity, draw resistance and draw resistance scattering to a filter material obtainable by a filter rod machine comprising a deflection device according to the invention.

The deflection device according to US 4,522,616 also works on a mechanical basis using a pulley. The strand coming from the pulley is introduced into a hopper by a forward flow of air from a nozzle located immediately in front of the hopper. This means that the nozzle is used exclusively to insert the strand into the hopper, whereby no distraction or deflection of the strand takes place. Due to the drive roller, which interacts with the deflection roller, the deflection of the filter tow is effected in a mechanical manner.

In a preferred embodiment, the deflection device is adapted such that the deflection of the at least one filter tow strand has at least one horizontal component. It has been found that due to the horizontal component of the deflection, the draw resistance and draw resistance scattering can be further improved. In contrast, the deflection device according to US 4,522,616 only a vertical deflection of the strand before.

The transport device may have at least one pneumatically operated transport nozzle, whereby a particularly simple technical implementation the transport device is achieved since conventional transport nozzles can be used.

Preferably, the transport device has two transport nozzles, which are arranged in the region of the inlet side and the outlet side of the device. The use of two transport nozzles, one nozzle of which is arranged downstream of the other nozzle, improves the flexibility of the manufacturing process. For example, the two nozzles can be operated at different pressures to influence the properties of the filter tow.

In a further embodiment of the invention, the deflection device comprises at least one curvature arc which determines the conveying path of the filter tow strand at least in sections. The use of a curvature arc in connection with the deflection device has the advantage that a continuous deflection of the filter tow strand is achieved.

In general, any component having a continuously curved configuration that causes a deflection of an airflow, such as a baffle, is suitable for implementing the baffle.

The curvature arc can be connected to the transport nozzle provided on the outlet side and / or with the transport nozzle provided on the inlet side, in particular detachably connected. In this way, the curvature arc and the transport nozzle act together directly, which ensures that the deflection is driven pneumatically or pneumatically. Due to the detachable connection between the curvature arc and the transport nozzle, in each case one of the two transport nozzles can be equipped with a curvature arc or both transport nozzles each with a curvature arc.

To adjust the position of the arc of curvature or the plurality of curvature arcs either with respect to the transport nozzle or with respect to an oppositely disposed arc of curvature can be provided be that the curvature arc or the plurality of curvature arcs are arranged rotatably or pivotally.

The lower limit of the curvature angle of the curvature arc may be at least 10 °, with preferred ranges between 10 ° - 80 °, 20 ° - 60 ° and 30 ° - 50 °.

A uniform transfer of the filter tow strand from a curve of curvature to the associated further curve of curvature can be achieved by the fact that the ends of the curved bends remote from the respective transport nozzle are aligned.

In a further preferred embodiment it is provided that the curvature arches are connected by a pipe section, in particular a rectilinear pipe section. This embodiment is to be regarded as preferred in particular for safety reasons, as it is avoided that a fast-running, unprotected filter tow line is accessible to operating personnel.

Moreover, the tube section is an effective means of increasing the length of the diverter, resulting in the positive effect of dampening pulsations, which become critical particularly at high processing speeds. Increased pulsations are related to the higher pressures applied to the inlet nozzle, which are necessary to ensure proper feeding of the strand into the finger. Due to the short guide channels in conventional deflection systems such pulsations are transmitted almost undamped on the format part of the machine. This leads to an increased scattering of the draw resistance, especially at high processing speeds. In addition, the increased length of the system according to this embodiment of the invention enhances the blooming effect.

The pipe section may be perforated at least in sections, whereby the escape of compressed air from the pipe section is made possible.

In a further preferred embodiment of the invention, the pipe section is provided with a feed device for feeding in additives, such as activated carbon, plasticizer and / or for feeding water. Due to the increased length of the system, the feed of additives and / or water in the pipe section leads to a homogeneous distribution of the additives and / or the water in the filter tow line. Moreover, the feeding of water in the pipe section of the deflector ensures a safe separation of the water supply from the triacetin, which must be anhydrous to prevent hydrolysis of the triacetin.

In another embodiment, a clearance is formed between the arcs of curvature, thereby enabling the release of chemical substances from the filter tow strand that have been added to the strand before it is introduced into the diverter.

Preferably, the deflecting device is adapted for a horizontal offset of the at least one filter tow strand of at least 5 cm, in particular from 5 to 50 cm, in particular from 10 to 40 cm, in particular from 15 to 30 cm. A suitable length of the device in order to achieve a good turbulence of the filter rod material is achieved if the total longitudinal length of the device is at least 200 mm, in particular 200-1000 mm, in particular 500-900 mm, in particular 600-800 mm.

Fig. 1

eine schematische Seitenansicht eines bevorzugten Ausführungs- beispiels einer Doppelstrangfilterstabmaschine gemäß der Erfin- dung;

Fig. 2

eine Draufsicht der Maschine gemäß Fig. 1; eine Seitenansicht im Teilschnitt der Umlenkeinheit bzw. Umlenkvorrichtung der Maschine gemäss Fig. 1, wobei aus Gründen der Klarheit Teile weggelassen wurden;

Fig. 4

einen Schnitt entlang der Linie IV-IV der Umlenkeinheit bzw. Umlenkvorrichtung gemäss Fig. 3;

Fig. 5

einen Querschnitt durch ein weiteres Ausführungsbeispiel der erfindungsgemässen Umlenkvorrichtung umfassend einen Rohrabschnitt;

Fig. 6

einen Querschnitt durch ein weiteres Ausführungsbeispiel der erfindungsgemässen Umlenkvorrichtung, wobei der Rohrabschnitt perforiert ist; und

Fig. 7

ein weiteres Ausführungsbeispiel der erfindungsgemässen Umlenkvorrichtung, das für eine Doppelstrangmaschine angepasst ist.

The invention will be explained in more detail below with reference to the embodiments schematically illustrated in the accompanying drawings. In these show:

Fig. 1

a schematic side view of a preferred embodiment of a double-stranded filter rod machine according to the invention;

Fig. 2

a plan view of the machine according to Fig. 1 ; a side view in partial section of the deflection or deflection of the machine according to Fig. 1 with parts omitted for the sake of clarity;

Fig. 4

a section along the line IV-IV of the deflection or deflection device according to Fig. 3 ;

Fig. 5

a cross section through a further embodiment of the inventive deflection device comprising a pipe section;

Fig. 6

a cross section through a further embodiment of the inventive deflecting device, wherein the pipe section is perforated; and

Fig. 7

a further embodiment of the inventive deflection device, which is adapted for a double-strand machine.

Reference numeral 1 in FIG Fig. 1 overall designates a double-strand machine for the production of cigarette filters. The machine 1 comprises a format part with two format sections 2a, 2b in each case for forming continuous filter rods 3a, 3b and, for each format section 2a, 2b, in each case one filter material feed 4a, 4b. The feeds 4a, 4b receive filter material from the conveyor line 5, which forms part of the machine 1 and extends between an inlet station 6 of the feeders 4a, 4b and a storage area 7 comprising two bales 8a, 8b of filter material.

As in the FIGS. 1 and 2 9, respective slivers 9a, 9b are unwound from the bales 8a, 8b and conveyed along the conveying path 5 by a guide roller arrangement 10a, which is arranged at the inlet station 6.

The conveyor line 5 comprises a double guide device 11, which is arranged above the bales 8a, 8b for guiding the lunts 9a, 9b. The conveyor line 5 further comprises a suction device 12, which is arranged directly in the conveying direction in front of the guide assembly 10a at the inlet station 6 to the Lunten 9a, 9b in the transverse direction in respective Partially flat strips 13a, 13b to pull apart, which are supplied to the guide device 10a. After the guiding device 10a, the two strips 13a, 13b are conveyed along the infeeds 4a, 4b in a substantially horizontal direction 14 by a pressing device 15 which comprises a guide roller or brake roller arrangement 10a and two drive roller arrangements 10b, 10c. The two strips 13a, 13b are then conveyed along the respective feeds 4a, 4b in the direction 14 through an expansion device 16 which injects air into the strips 13a, 13b in order to increase their volume. Thereafter, the strips 13a, 13b are transported through a conditioning device 17, where chemical substances, in particular triacetin, are added to the strips 13a, 13b so as to impart moldability and / or aroma to the filter material. Finally, the two strips 13a, 13b are conveyed along the respective feeds 4a, 4b in the direction 14 by a drive roller assembly 10d, which is constructed similarly to the arrangements 10b, 10c and defines a discharge region of the feeds 4a, 4b or feed paths 4a, 4b.

The feeds 4a, 4b are connected to the format sections 2a, 2b of the format part by a deflection unit or deflecting device 18, which is immediately downstream of the roller arrangement 10d. The deflection unit 18 receives the strips 13a, 13b from the feeds 4a, 4b, collects the strips 13a, 13b uniformly to form two strands of filter material and conveys the filter material strands to the format sections 2a, 2b. In the two format sections 2a, 2b, each filter material strand is conveyed onto a paper strip 19a, 19b which has been previously gummed in a gumming station 20 and then wound transversely around the filter material strand to form a continuous filter rod 3a, 3b.

At the output of the format sections 2a, 2b control one or more control stations 21 different quality characteristics of the filter rods 3a, 3b (for example, density, diameter, appearance ...). A cutting head 22 transverses the bars 3a, 3b transversely into respective subsequent filter sections (not shown). As in the Figures 3 . 4 represented, the Deflection unit 18, a housing 23 which is fixed to the frame of the machine 1 and inside two laterally juxtaposed deflection lines 24a, 24b holds, which converge to reduce the distance between the two filter material strands.

Each deflection line 24 comprises an inlet funnel 25, into which the strip 13 is conveyed out of the feed 4, and a downstream outlet funnel 26, through which the filter tow line is conveyed to the format line 2. The inlet funnel 25 and the outlet funnel 26 each have a nozzle, by means of which a drive gas flow, in particular air flow, is generated to convey the strand. The funnels 25, 26 therefore each function as a transport nozzle. Each hopper 25 has a straight central axis of symmetry 27, which runs parallel to the conveying direction, or lies in the conveying plane of the strip 13 in the region of the feed 4. Each outlet funnel 26 likewise has a rectilinear central axis of symmetry 28, which runs inclined with respect to the conveying direction of the filter material strand out of the inlet funnel 25 and with respect to the conveying direction of the filter material line along the format line 2. Between the respective inlet funnel 25 and outlet funnel 26, a tubular deflection part is arranged, in particular a curvature arc 29, which has a curved section for deflecting the conveying direction of the filter material strand from the inlet funnel 25. Each arc of curvature 29 is preferably connected directly to the outlet of the inlet funnel 25.

To further improve the homogeneity of the filter material in the filter material strand, air is injected into each funnel 25, 26. Concretely, each hopper 25, 26 comprises a tubular body 30 having a narrowly tapered entrance area (ie, with a gradually decreasing flow channel diameter) and a cylindrical intermediate section (ie with a constant flow channel diameter). Each hopper 25, 26 further includes a slightly flared further tubular body 31 (ie, having a gradually increasing flow channel diameter) downstream of the tubular body 30.

The tubular body 30 is screwed into the further tubular body 31, whereby between an outer surface of the tubular body 30 and an inner surface of the further tubular body 31, a tubular air flow channel 32 is limited, in which a plurality of injection ports 33 open, which are the inner surface of the tubular Break body 30 in the cylindrical intermediate section. Supply channels 34 are formed in the further tubular body 31, through which, in operation, compressed air is introduced into the tubular channel 32 and from there through the injection openings 33 into the flow channel of the tubular body 30.

The injection openings 33 in the inlet funnel 25 are oriented with respect to the central axis of symmetry 27 in such a way that the air flow has an axial component, i. a component parallel to the central axis of symmetry 27, imprinted.

In a modification, the injection ports 33 in the feed hopper 25 are oriented with respect to the central axis of symmetry 27 such that both an axial component and a radial component (i.e., perpendicular to the central axis of symmetry 27) are impressed on the airflow. In this case, the axial air flow component prevails, which serves to press the filter material through the inlet funnel 25, whereas the radial air flow component serves to swirl the air flow.

The injection openings 33 in the discharge funnel 26 are oriented with respect to the central axis of symmetry 28 such that primarily an axial component (ie parallel to the central axis of symmetry 28) of the air flow is impressed, whereby the feed acting on the filter material is maximized.

During assembly and adjustment of the diverter unit 18, the air flow area of each tubular channel 32 can be adjusted by screwing the tubular body 13 into and out of the further tubular body 31, thereby adjusting the air velocity and flow through the injection openings 33.

It should also be noted that the filter rod material is conveyed between each inlet hopper 25 and outlet hopper 26 through the clearance 35, the filter rod material being exposed, i.e., free, to flow. moved without guide part.

In modification of the in the FIGS. 1 to 4 As shown, each hopper 25 may be connected to the corresponding hopper 26 through a perforated tubular expansion member.

The clearance 35, through which the filter rod material is moved freely, allows expansion of the injected through the injection ports 33 of each inlet funnel 25 compressed air, whereby unwanted backpressure phenomena are avoided. Furthermore, it is thereby made possible for the filter rod material to release excess chemical substances which have been added in the treatment device 17. In order to collect and remove the released from the filter rod material chemical substances, the housing 23 is arranged inclined downwards and has at the lowest point a collecting channel, which leads to a catch basin. In order to prevent the chemical substances released from the filter rod material from escaping from the housing 23 and contaminating the rest of the machine 1, the housing 23 is substantially sealed and has only outlet openings arranged in a central region of the housing 23 and against direct spraying are shielded.

In order to allow free expansion of the compressed air injected through the injection ports 33 into each discharge hopper 26 (thus avoiding undesirable backpressure phenomena), each discharge hopper 26 is provided with a slightly conical perforated tubular body 37 having a plurality of openings 38 and the Outlet funnel 26 is located immediately downstream. The passage openings 38 in each perforated tubular body 37 are preferably arranged only on the upper side of the perforated tubular body 37 in order to avoid a downwardly directed air flow, ie an air flow directed onto the format section 2.

In an alternative embodiment, not shown, each deflection section 24 of the deflection unit 18 comprises one, two or even more intermediate funnels, which are arranged between the inlet funnel 25 and the outlet funnel 26 and are constructed identically to the funnels 25, 26.

In another embodiment, not shown, the machine 1 described above is designed as a single-strand machine and therefore comprises a format part with a format section 2 to form a continuous filter rod 3 and a filter material supply 4. In this case, the deflection unit or deflection device 18 comprises a deflection path 24 with above Similarly, the machine 1 described above may be formed as a triple or quadruple strand machine and thus a format part with three or four format plug 2 to form three or four continuous filter rods 3 and three or four filter material feeds. 4 include. In this case, the deflection unit or deflection device 18 has three or four deflection paths 24, which are each equipped with the inlet and outlet funnels 25, 26 described above.

The filter material obtainable with the deflector 18 described above has excellent homogeneity and, at least in terms of homogeneity, is superior to filter materials made with the deflector currently available on the market.

The drive roller assemblies 10b, 10c, 10d are different along the feeds 4a, 4b in size and arrangement, but are functionally identical. The following description therefore refers only to one of the drive roller assemblies 10b, 10c, 10d, which is designated by the reference numeral 10 for the sake of simplicity. Each drive roller assembly 10 includes, for each feed 4, a drive roller rotated by a motor independent of the motors of the other rollers and a free rotating roller which abuts and engages the drive roller. The two motors of the two drive rollers of each drive roller assembly 10 may be located on the same side of the feeders 4 in the machine frame. Alternatively, in each drive roller assembly 10, the motor of a drive roller in the frame of the machine 1 and the motor of the other drive roller may be arranged adjacent to the drive roller.

Hereinafter, the deflection device, which is also referred to as a deflection unit 18, described in detail.

As in the Figures 3 . 4 shown, the deflection device essentially comprises a deflection device 50 and a transport device 40, which cooperate with each other such that the deflection of the filter tow rope 13, which is moved by the deflection device, takes place pneumatically.

There are various ways to realize the deflection technically. For example, it is possible, as in the Fig. 3 . Fig. 4 illustrated to use a curvature arc 29 which is connected to the pneumatically driven transport nozzles 25, 26. In the in the Fig. 3 . Fig. 4 As shown, only the transport nozzles 25a, 25b on the inlet side of the deflecting device 18 are each provided with a curvature arc 29a, 29b.

It is also possible to provide only the transport nozzles 26a, 26b on the outlet side of the deflection device each with a curvature arc (not shown). A further option is to provide both the transport nozzles 26 on the outlet side and the transport nozzles 25 on the inlet side of the deflection device with respective curved bends 29 ( Figures 5-7 ).

In general, it is possible to arrange the curve of curvature either of the associated transport nozzle in the conveying direction, as in Figures 3 . 4 represented, which means that the strand is pressed pneumatically, ie by the supply of compressed air through the arc of curvature 29. When the curvature arc 29 is arranged in the conveying direction above the respective transport nozzle, as in the FIGS. 5 to 7 shown for the transport nozzle 26 on the discharge side of the deflecting device, the strand is sucked through the arc of curvature 29.

It is also possible to arrange the curvature arc 29 in the conveying direction above and / or below the respective nozzle, wherein the alternative of arranging the curvature in the conveying direction below the nozzle and thus to pneumatically press the strand through the curvature, leads to better results in terms of Draw resistance and draw resistance spread of the filter material.

In Fig. 4 , as well as in the FIGS. 5 to 7 It can be seen that the deflector 50 is adapted to effect a deflection of the filter tow string in a direction comprising at least one horizontal component. In the in Fig. 3 As shown, the deflection is carried out with both a horizontal and a vertical component, since the entire deflection device is arranged inclined with respect to a horizontal plane.

Diversion generally means that the conveying direction is changed at least once.

For the technical realization of the deflection device 50, the curvature bends 29 can be replaced by other means, for example by components with an open structure, in particular by a curved baffle plate, which is associated with the pneumatic transport device 40. The curved baffle plate can be used to achieve the desired offset of the filter tow string 13 while continuously redirecting the filter tow string.

In general, components for the technical implementation of the deflection device 50 can be used, which enable a continuous and pneumatically driven deflection of the filter tow. This means that the deflection device 50 should have at least one continuously curved wall which limits the guide path of the filter tow strand at least in sections and at the same time changes the conveying direction. In general, the deflection device 50 comprises a deflection part, which is arranged between an inlet funnel or an inlet-transport nozzle and a discharge funnel or a discharge transport nozzle. The deflection part may be tubular and comprises a curved section for deflecting the conveying direction of the filter material strand or the sliver coming from the inlet funnel or the inlet transport nozzle.

If the deflection device is to be used in a double-strand machine, it is advantageous to change the conveying direction such that the two strands are fed to one another, ie converge ( Fig. 4 ). The strands can then be fed to the infeed system of a format part of the machine. In other cases, it may be useful to redirect the strand in a different direction, for example, when two separate format parts are used, which are arranged spaced from each other.

The device is designed to be even more flexible when the bends 29 are detachably connected to the respective transport nozzle 25, 26, since the device can then be adapted to different process conditions. Moreover, the curvature bends 29 can be arranged to be pivotable, whereby the direction under which the strands leave the respective curvature arc 29 can be changed. The curvature arc 29 on the inlet side and the curvature arc 29 on the outlet side of the device can be easily aligned by the respective curvature arcs 29 are pivoted accordingly.

As in Fig. 4 can be seen, each curvature arc 29a, 29b oriented on the inlet side of the device such that the central axis of symmetry of the free end of the arc of curvature 29a, 29b, the central axis of symmetry of the remote transport nozzle 26a, 26b on the outlet side of the device in the inlet plane intersects. This alignment of the arc of curvature 29a, 29b with respect to the delivery nozzles 26a, 26b on the outlet side of the device provides for uniform transfer of the strand 13 from the respective arc of curvature 29a, 29b to the transport nozzles 26a, 26b.

The embodiment according to the Figures 3 . 4 relates to a deflection device having a clearance 35 between the curvature arches 29a, 29b and the outlet transport nozzles 26a, 26b. Alternatively, it is also possible to provide a pipe section 51, in particular a straight pipe section 51, which connects a curvature arc 29 on the inlet side of the device and a curvature arc 29 'on the outlet side of the device. In order to achieve the desired offset of the system, the two curvature arcs 29, 29 'are curved in opposite directions, with the central axis of symmetry of the arcs 29, 29' coaxial with the central axis of symmetry of the respective transport nozzle 25, 26 being parallel. Moreover, the ends of the respective curvature arcs 29, 29 ', which are located away from the respective associated transport nozzle 25, 26, are aligned, so that the pipe section 51 can be fitted between the two curvature arcs 29, 29'.

The pipe section 51 is an extremely effective means for increasing the length of the pipe system. This enhances the turbulence of the filter material that can be achieved with the system and the blooming effect. The pipe section 51 does not necessarily have to extend straight. It is also possible to use a pipe section which, at least in sections, has bends or is generally curved.

As in Fig. 6 As shown, the pipe portion 51 may be perforated to allow compressed air to be discharged through the transport nozzle 25 on the inlet side of the apparatus.

In a further preferred embodiment of the invention, which is not shown in the figures, a supply device is associated with the pipe section, which allows the feeding of additives, such as activated carbon, plasticizer or other substances into the filter tow line. Moreover, the feeder can be used to feed water into the strand, thereby affecting the cure time. A particular advantage of the pipe section 51 is that the length of the system is increased. This makes it possible that the injected additives and / or the injected water is distributed homogeneously over the length of the pipe section in the filter tow line. The quality of the filter rods, which are produced with a machine comprising such a deflection device, can thus be significantly improved.

With regard to the dimension of the deflection device, it is advantageous that the horizontal offset of the deflection device 50 is at least 5 cm. A preferred range is 5 - 50 cm, in particular 10 - 40 cm, in particular 15 - 30 cm. The total longitudinal length of the device should be at least 200 mm. This means that the axial distance between the inlet side and the outlet side of the device is at least 200 mm. Preferred ranges are from 200 to 1000 mm, in particular 500 to 900 mm, in particular 600 to 800 mm.

The angle of curvature of each arc of curvature is at least 10 °. The curvature angle is the acute angle between the two central axes of symmetry of a curvature arc. The angle of curvature in Fig. 7 is denoted by a. Preferred ranges are between 10 ° - 80 °, in particular 20 ° - 60 °, in particular 30 ° - 50 °.

The deflecting device described above can be used for both a single-stranded as well as a double-strand machine, the embodiments provided for the single-strand machine in the FIGS. 5 and 6 and provided for the double-strand machine embodiments in the Figures 1 - 4 and 7 are shown.

The pipe systems according to the FIGS. 5 to 7 can also be arranged in a housing 23, as for the deflection device 50 according to the Figures 1 - 4 intended.

To summarize, the device according to the invention improves the draw resistance as well as the draw resistance spread due to the combined deflection and pneumatic conveying, which leads to an improvement of the turbulence in the system and thus to an increased homogeneity of the filter material.

Moreover, the deflection devices described above allow damping of the pulsations that occur at higher processing speeds. The damping of the pulsations is due to the increased length of the conveying path, in particular in connection with the use of a pipe section between two associated curves on the inlet and outlet side of the device. In this way, the flowering effect can be improved.

LIST OF REFERENCE NUMBERS

1

machine

2a, 2b

format routes

3a, 3b

filter rods

4a, 4b

additions

5

conveyor line

6

infeed station

7

storage area

8a, 8b

bale

9a, 9b

fuse

10a

Guide roller assembly

10b, 10c

Drive roller assembly

10d

roller assembly

11

Double guide device

12

suction

13a, 13b

strand

14

horizontal direction

15

presser

16

expander

17

conditioning device

18

Deflection unit or deflection device

19a, 19b

Strip of rubberized paper

20

gumming

21

control station

22

cutting head

23

casing

24a, 24b

deflecting sections

25, 26

transport jets

27.28

axes of symmetry

29

curvature arch

30

tubular body

31

another tubular body

32

air duct

33

injection openings

34

supply channels

35

free space

36

outlet

37

perforated tubular body

40

transport means

50

deflecting

51

pipe section

Claims (19)

1. A cigarette filter manufacturing machine (1); the machine (1) comprising:

   a number of feed lines (4) for respective continuous strips (13) of filtering material;

   a number of forming beams (2) for forming respective continuous filter rods (3); and

   a twisting assembly (18) which is located between the feed lines (4) and the forming beams (2), receives the strips (13) from the feed lines (4), gathers the strips (13) uniformly into two ropes of filtering material, and feeds the ropes of filtering material to the forming beams (2);

   wherein the twisting assembly (18) comprises a number of twisting lines (24), each of which comprises an input funnel (25) into which the strip (13) from the feed line (4) is fed;

   characterized in that each twisting line (24) of the twisting assembly (18) comprises an output funnel (26) which is separated and located downstream from the input funnel (25), and through which a rope of filtering material is fed to the forming beam (2).
2. A machine (1) as claimed in Claim 1, wherein the twisting lines (24) of the twisting assembly (18) are side by side and converge to reduce the distance between the ropes of filtering material.
3. A machine (1) as claimed in Claim 1 or 2, wherein each input funnel (25) has a central axis (27) of symmetry which is straight and parallel to the feed direction/lies in the feed plane of the strip (13) from the feed line (4).
4. A machine (1) as claimed in Claim 1, 2 or 3, wherein, between each input funnel (25) and the output funnel (26), there is interposed a diverting member (29), which is tubular and comprises a curved portion for diverting the feed direction of the rope of filtering material from the input funnel (25).
5. A machine (1) as claimed in Claim 4, wherein each diverting member (29) is fitted directly to the outlet of the input funnel (25).
6. A machine (1) as claimed in one of Claims 1 to 5, wherein each output funnel (26) has a central axis (28) of symmetry, which is straight and inclined slightly with respect to the feed direction of the rope of filtering material from the input funnel (25), and with respect to the feed direction of the rope of filtering material along the forming beam (2).
7. A machine (1) as claimed in one of Claims 1 to 6, wherein air is blown into each funnel (25, 26) through blow holes (33) which debouch inside the funnel (25, 26).
8. A machine (1) as claimed in Claim 7, wherein each funnel (25, 26) comprises a first tubular body (30), and a second tubular body (31) downstream from the first tubular body (30); the first tubular body (30) is screwed inside the second tubular body (31) to define, between an outer surface of the first tubular body (30) and an inner surface of the second tubular body (31), a tubular airflow channel (32) which debouches inside the blow holes (33).
9. A machine (1) as claimed in Claim 8, wherein the first tubular body (30) comprises a narrowly tapering initial portion and a cylindrical intermediate portion; and the second tubular body (31) flares slightly.
10. A machine (1) as claimed in Claim 8 or 9, wherein the blow holes (33) of each input funnel (25) are oriented with respect to the central axis (27) of symmetry to impart both an axial component and a radial component to the airflow.
11. A machine (1) as claimed in Claim 8 or 9, wherein the blow holes (33) of each input funnel (25) are oriented with respect to the central axis (27) of symmetry to only impart an axial component to the airflow.
12. A machine (1) as claimed in one of Claims 8 to 11, wherein the blow holes (33) of each output funnel (26) are oriented with respect to the central axis (28) of symmetry to only impart an axial component to the airflow.
13. A machine (1) as claimed in one of Claims 1 to 12, wherein, between each input funnel (25) and the output funnel (26), the rope of filtering material is fed through a clear area (35), in which the rope of filtering material travels freely with no guiding members.
14. A machine (1) as claimed in Claim 13, wherein the twisting assembly (18) comprises a box body (23) internally supporting the twisting lines (24).
15. A machine (1) as claimed in Claim 14, wherein, to collect and drain off the chemical substances released by the ropes of filtering material, the box body (23) is tilted downwards, and comprises, at the lowest point, a catch channel which drains into a catch tank.
16. A machine (1) as claimed in Claim 14 or 15, wherein the box body (23) is substantially sealed, and comprises compressed-air relief openings (36) shielded against direct spray.
17. A machine (1) as claimed in one of Claims 1 to 16, wherein each output funnel (26) is fitted with a perforated tubular body (37) having a number of through holes (38) and located immediately downstream from the output funnel (26).
18. A machine (1) as claimed in Claim 17, wherein the through holes (38) in each perforated tubular body (37) are only formed in the top of the perforated tubular body (37) to prevent airflow being directed onto the forming beam (2).
19. A machine (1) as claimed in one of Claims 1 to 18, wherein each twisting line (24) of the twisting assembly (18) comprises at least one intermediate funnel located between the input funnel (25) and the output funnel (26).

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