EP2213184B1 - Device for providing filter tow material and device for producing filters - Google Patents

Abstract

At least two filter tow strips (4,6) are fed along respective guide paths. Each guide path is associated with its own processing device (28,30), which is separately controllable. Preferably, a different filter tow material is provided for each tow guide path.

Description

The invention relates to a device for processing filter tow material for the production of filters for rod-shaped smoking articles such as cigarettes, with filter tow providing means for providing at least two filter tows, at least two tow guideways, one of which is guided in each Towführungsbahn a filter tow, and processing means for processing the filter tow , Furthermore, the invention relates to a device for the production of filters for rod-shaped smoking articles such as cigarettes with such a device and with a wrapping device for wrapping the filter tow with wrapping material and an adhesive application device for bonding the wrapping material.

Such a device is for example off DE 42 09 789 A1 or DE 43 08 093 A1 known. With these known devices filter rods can be produced in the two-strand process. In this case, filter tow strips (eg made of cellulose acetate threads) are removed from a bale, processed by stretching and treating with softener and delivered in a desired shape and consistency for further processing to a filter strand unit, which from the processed filter tow strips by wrapping with a wrapping material strip produces a filter strand, which is finally cut into filter rods for cigarettes or other rod-shaped smoking article.

The invention is based on the object to further improve a device of the type mentioned.

This object is achieved by a device having the features of claim 1.

With the aid of the invention, not only at least two filter tow strips are simultaneously produced and processed, but the processing means are separately controllable with respect to each tow path. By this invention proposed measure results in not only a significant increase in productivity of the filter production at relatively low design and mechanical engineering effort and less space and area compared to the use of a corresponding number of single-strand machines, but it is also on the one hand a partial load operation possible and can be make different types of filters on one and the same device and prepare. The latter is inventively achieved in that the each Towführungsbahn associated processing device is controlled separately from the other Towführungsbahnen associated processing facilities. Thus, the properties of the products to be produced in the different tow guideways can be influenced individually, which in the different tow guideways not only products with matching properties, as it is exclusively according to the teaching of DE 43 08 093 A1 is practiced, but also products with different Properties can be produced and processed, which is increasingly demanded by the market.

For the production of different types of filters, it may be appropriate that the filter tow providing means provide a different filter tow material for each tow path. Typically, the filter tow standby means consist of two or more bales, with each bale stripping off a filter tow, or a bale and a downstream cutter which cuts the strip of material withdrawn from the bale longitudinally into two or more separate filter tows.

Usually, each processing device has means for spreading, stretching and / or treating the filter tow material. According to the invention, these means for spreading, stretching and / or treating the filter tow material are each separately controllable with respect to each tow path, in order to achieve the effects described above. Thus, for example, in each case a separately controllable means for stretching should be provided in each of the towpath in order to individually stretch the relevant filter tow strip in the associated towpath. The means for stretching the filter tow material are particularly well suited for the individual manipulation of the filter tow strips in the respective tow guideways because they have characteristic properties, such as e.g. the density or draw resistance directly affecting manufactured products.

Each tow guideway is associated with means for spreading, stretching and / or treating the filter tow material and the means for spreading, the means for stretching and / or the means for treating each form a unit in which they are arranged transversely to the direction of the Towführungsbahnen side by side. In this embodiment, according to the number of Towführungsbahnen a corresponding number of means for spreading, a corresponding number of means for stretching and / or a corresponding number of means are provided for treating, all Means for spreading a unit, all means for stretching a unit and / or all means for treating each form a unit.

In a further development of the aforementioned embodiment, each means for spreading and / or stretching has a roller pair driven by associated drive means and mounted on one side. The one-sided storage of the roller pairs has the advantage of better accessibility in particular when setting up the device or in the event of the elimination of malfunctions.

In a further development of the aforementioned embodiment, the roller pairs of a unit forming means for spreading and / or stretching are coaxially juxtaposed, resulting in a particularly space-saving arrangement. In this case, the first roller of the outer roller pair can sit on a first shaft and the first roller of the inner roller pair on a first tube, through which the first shaft extends. The same separate storage by means of a shaft-hollow shaft arrangement can also be realized for the second rolls of the roller pairs. Accordingly, in this embodiment, at least the rollers of the inner roller pair are formed as hollow rollers.

A further preferred embodiment is characterized in that the means for treating the Filtertowmaterials an angularly, preferably transversely, over the Towführungsbahnen extending spray box assembly on its the Towführungsbahnen facing wall with the Towführungsbahnen associated discharge opening for delivery of treatment liquid on the Filtertowmaterial is provided, wherein at the points between the tow guideways in each case a first partition wall within the Sprühkastenanordnung and a second partition on the Towführungsbahnen facing wall is arranged to prevent mutual interference in the treatment of the filter tow material in the various tow guideways and in particular misting by turbulence ,

In a further development of the aforementioned embodiment, the cross-section of the discharge openings with respect to each Towführungsbahn, preferably with the aid of movable metering plates, separately changed to treat the filter tow material in each Towführungsbahn individually. In this case, preferably either per Towführungsbahn a discharge opening, which usually is slit-shaped, or a plurality of discharge openings, which are usually formed as round holes may be provided.

Conveniently, the spray box assembly is pressurizable. Alternatively or in addition, however, it is also conceivable that the spray box arrangement contains at least one rotating brush driven by a drive which throws the treatment liquid through the discharge openings.

Furthermore, downstream of a forming device for forming two round filter tows from two filter tows, two double-cranked tapered inlet fingers may be provided through each of which a filter tow is guided to reduce the distance between the filter tows and achieve parallel alignment of the filter tows.

In a further development of the aforementioned embodiment, the inlet fingers can be fastened to a common holder, which is suspended from a parallelogram frame which can be pivoted substantially in the direction of the filter tow cord. In this way, both inlet fingers, preferably parallel to a machine wall, pivot backwards, in particular for the purpose of setting up the machine or for the purpose of maintenance.

Furthermore, downstream of the shaping device, deflection means, which preferably have at least one deflection roller, can be provided for deflecting the round filter towstring so as to pivot the towpath in any direction. Such deflection means can be used, for example, similar to the aforementioned inlet fingers for reducing the distance between the filter tows. Alternatively or additionally, can be realized by the arrangement of deflecting a corner line between the apparatus for processing of filter tow and an adjoining Filterstrangeinheit. Finally, by twisting the tow in the stretching zone, the deployment of towballs could optionally be possible at different locations.

Furthermore, at the end of each tow guide track, a separate removal device may be provided, which preferably has a push-in drum or a transfer spreader for transferring the cut filter tow bars from a movement in their longitudinal direction into a movement transversely to their longitudinal direction. The arrangement of such separate removal devices, it is possible to use different and in particular physically separately set up Filterstrangeinheiten or cigarette manufacturing machines. The EP 0 682 881 B1 already teaches the training and pairwise arrangement of push-in drums; However, these conventional push-in drums are used for the transport of cut cigarette rods and are coupled with other transfer drums so that the cigarette rods emitted from both push-in drums are reunited into a common stream.

Figur 1

eine schematische perspektivische Seitenansicht einer Zweistrang-Maschine gemäß der Erfindung;

Figur 2

eine schematische Seitenansicht der Maschine von Figur 1;

Figur 3

eine perspektivische Ansicht auf einen Teil der Maschine von Figur 1;

Figur 4

die koaxiale Lagerung zweier Walzen in geschnittener Ansicht;

Figur 5

eine vergrößerte perspektivische Darstellung eines Teils der Maschine von Figur 1;

Figur 6

eine schematische perspektivische Ansicht des ausgangsseitigen Teils der Maschine von Figur 1;

Figur 7

eine Draufsicht auf den ausgangsseitigen Teil der Maschine von Figur 1; und

Figur 8

eine schematische ausschnittsweise Seitenansicht auf einen Einlauffinger und dessen Halterung an einem Parallelogrammgerüst.

Hereinafter, preferred embodiments of the invention will be explained in more detail with reference to the accompanying drawings. Show it:

FIG. 1

a schematic perspective side view of a two-strand machine according to the invention;

FIG. 2

a schematic side view of the machine of FIG. 1 ;

FIG. 3

a perspective view of a part of the machine of FIG. 1 ;

FIG. 4

the coaxial bearing of two rolls in a sectional view;

FIG. 5

an enlarged perspective view of a part of the machine of FIG. 1 ;

FIG. 6

a schematic perspective view of the output side of the machine of FIG. 1 ;

FIG. 7

a plan view of the output side of the machine of FIG. 1 ; and

FIG. 8

a schematic partial side view of an inlet finger and its support on a parallelogram framework.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, there is shown partly and completely in detail a machine according to the invention for processing filter tow material for the manufacture of rod smoking filters such as in particular cigarettes in the string process, the figures being only substantially those required for the understanding of the invention Parts included. In machine engineering usual components of the machine such as details of the machine frame, brackets, bearings and panels are in the drawing in the interest of their clarity not essentially represents. Identical parts are provided with the same reference numerals in all figures.

The illustrated filter fabric preparation machine has two tow guideways 2 and 3, which lead two filter cloth strips 4 and 6 side by side through the machine. The filter tow strips 4 and 6 are drawn off from a filter tow stock 7, which contains two filter tow bales 8 and 9 next to one another in the illustrated embodiment. Alternatively, it is also conceivable to stock the filter tow strips 4 and 6 in a common bale or to strip a wider strip of material from a single bale and then to cut it in the direction of its longitudinal extent by a cutting device into two separate filter tow strips.

Above the filter tow reservoir 7, the machine in the illustrated embodiment, a deflection and Towausbreitungsorgan 10, which is arranged at the upper end of a support arm 12 and has two adjacent same tow guides 14. Furthermore, 10 first spreader nozzles 16 are provided on the deflection and Towausbreitungsorgan, each on Both filter tow strips 4 and 6 act to spread them each in a flat strip.

On a schematically illustrated machine frame 20, second spreader nozzles 22 are arranged, on which the filter tow strips 4 and 6 coming from the deflecting and Towausbreitungsorgan 10 are guided along.

The second spreader nozzles 22 are adjoined by a two-track stretching device 24. How the particular Figures 2 and 3 1, this stretching device 24 has first and second pairs of brake rollers 26, 27, first and second pairs of draw rollers 28 and 29 located downstream of the pairs of braking rollers 26, 27, and third and fourth pairs of draw rollers 30 and 31 located downstream of the first and second pairs of draw rollers 28, 29 , Here, the first pair of brake rollers 26, the first pair of stretching rollers 28 and the third pair of stretching rollers 30 of the first Towführungsbahn 2 and the second pair of brake rollers 27, the second pair of draw rollers 29 and the fourth pair of draw rollers 31 of the second Towführungsbahn 3 assigned.

The first and second pairs of brake rollers 26 and 27, the first and second pairs of draw rollers 28 and 29 and the third and fourth pairs of draw rollers 30 and 31 are respectively disposed coaxially with each other and juxtaposed. In this connection, reference should more particularly be made to the one-sided support of the drafting roller pairs 28, 29 and 30, 31 on a vertical rear wall 32 of the machine frame 20, which allows good accessibility in particular when setting up a machine or in the event of malfunctioning, in particular the FIGS. 1 and 3 reveal.

The one-sided storage in particular of the drafting rollers is realized in the illustrated embodiment by means of a shaft-hollow shaft arrangement, which is exemplified by the first rollers 28a, 29a of the first and second pairs of draw rollers 28, 29 in FIG. 4 is shown schematically in cross section. Thereafter, the outer roller 29a is rotatably coupled to a shaft 34 and coaxial therewith arranged. This shaft 34 is guided by a tube 36, arranged coaxially to this and rotatably mounted on this. This tube 36 is flange-mounted on the machine frame. On the machine frame further comprises a first drive 38 is arranged, which rotatably drives the shaft 34 and thus the outer roller 29a, for which in the illustrated embodiment, the output shaft 38a of the first drive 38 rotatably coupled to the shaft 34 and is arranged coaxially thereto. The inner roller 28a surrounds the tube 36 and is arranged coaxially therewith and rotatably mounted thereon. Like the outer roller 29a, the inner roller 28a is driven by its own drive. These are in the illustrated embodiment according to FIG. 4 about a second drive 40, whose output shaft 40a is coupled via a gear transmission 42 with the inner roller 28a. The same arrangement is also provided in the third and fourth roller pairs 30 and 31.

Accordingly, each of the first, second, third and fourth pairs of draw rolls 28, 29, 30 and 31 is assigned its own drive, which can be controlled separately by a control device, not shown. In this way, the properties of the two filter tow strips 4 and 6 in the two Towführungsbahnen 2 and 3 can be controlled independently and thus adjusted, making it possible to produce filter rods in the two Towführungsbahnen 2 and 3 with different properties.

As the FIGS. 1 to 3 Each of the first, second, third and fourth draw roll pairs 28, 29, 30 and 31 includes a thinner, smaller diameter roll and a thicker, higher diameter roll. Usually, the thinner roll of each drafting roller pair is made of steel and is driven separately by the associated drive. On the other hand, the thicker rolls are usually formed as rubber rolls or provided with an outer rubber layer. In this case, the thicker rolls are usually mounted without drive, but separately adjustable transversely to its axis of rotation by actuators, not shown. Due to this separate suspension of the thicker rollers, it is also possible to be able to influence the contact pressure separately.

The third and fourth draw roller pairs 30 and 31 are driven by the separate drives associated with them at a higher peripheral speed than the first and second draw roller pairs 28 and 29, so that between the first and third draw roller pairs 28 and 30 and between the second and fourth draw roller pairs 29 and 31 in each case a defined stretching of the associated filter tow strip 4 or 6 takes place. As already mentioned and in FIG. 1 As can be seen, the first and third draw roll pairs 28 and 30 engage the first filter tow 8 and the second and fourth draw roll pairs 29 and 31 the second fill tow line 6, whereby, as already mentioned, the two filter tow strips 4 and 6 can be stretched independently.

This also applies, as already mentioned, for the brake roller pairs 26 and 27. For the first brake roller pair 26 is the first Fillertowstreifen 4 and the second pair of brake rollers 27 associated with the second Fiitertowstreifen 6. The pairs of brake rollers 26 and 27 are therefore also operated separately by separately associated actuators, with which the force exerted by the brake roller pairs 26, 27 on the filter towers 4, 6 braking force can be influenced. As actuators, which are not shown in the figures, for example, electric brakes may be provided which transmit braking torque to the brake rollers 26, 27, or it may be provided electrical, hydraulic or pneumatic adjusting members, which at least one roller of the two pairs of brake rollers 26, 27 adjust transversely to the axis of rotation and thus influence the contact pressure of the brake rollers against each other.

Downstream of the arrangement of the third and fourth drafting roller pairs 30, 31 follows as a means for treating the filter tow material with additives an applicator 44 for applying liquid plasticizer on the spread filter towers 4, 6. As in particular the Figures 3 and 5 can recognize the applicator 44 has a spray box 46 which extends across both tow guideways 2 and 3. The filter tow strips 4 and 6 facing top 48 of the spray box 46 has two adjacent slot-shaped openings 49 and 50, wherein the first opening 49 of the first tow guide track 2 and the second opening 50 of the second tow guide track 3 is assigned. In the illustrated embodiment, behind the slot-shaped openings 49 and 50 each have a perforated plate 52, whereby the plasticizer liquid emerges in the form of several rays upwards.

In the spray box 46 can be arranged in a known manner, at least one cylindrical rotating brush, which is not shown in detail and is driven by a motor, also not shown. The plasticizer is supplied through one or more openings, also not shown, on the side or the underside of the spray box 46, through which the plasticizer is supplied by means of likewise not shown pumps from a plasticizer supply, also not shown.

In the illustrated embodiment, the discharge amount of the plasticizer is controlled in particular by adjusting the opening width of the openings 49 and 50. For this purpose, so-called metering plates 53 and 54 are provided which are movable in the direction of movement of the filter tow strips 4, 6 and selectively open or close the openings 49, 50 partially or completely. The metering plates 53 and 54 are driven by actuators, not shown, which are controlled independently by a control device, also not shown. Thus, the opening width of the openings 49, 50 is controlled independently. This offers, in addition to the individual control of the pairs of brake rollers 26, 27 and the pairs of draw rolls 28 to 31, a further possibility to individually influence and determine the properties of the two filter tows 4 and 6 in order to be able to produce different products from the filter tows 4 and 6.

The movement of the stretched and now relaxing filter tow strips 4 and 6 over the application device 44 can lead to turbulences of the delivered plasticizer, which undesirably influences the distribution of the sprayed plasticizer and leads to misting leads. To avoid such Fehlbenetzungen, the two openings 49 and 50 are separated by a separating plate, in particular the Figures 3 and 5 reveal. The separating plate 56 is seated on the upper side 48 of the spray box 46, is vertically aligned and extends in the space formed between the two filter tow strips 4 and 6. In addition, in the same way, the interior of the spray box 46 is divided centrally by a further internal partition, which is not shown in the figures. Through this internal partition, the interior of the spray box 46 is divided into two substantially independent spray chambers. Therefore, it is also advantageous to divide the aforementioned rotary brush into two brushes, each of which brush sits in a spray chamber and optionally still separately driven and controlled. Furthermore, it is advantageous in this context to provide two pumps, one pump of which pumps the plasticizer individually into a spray chamber.

On the basis of such an independent regulation of the plasticizer supply and discharge, it is conceivable, for example, to carry out a dry removal in a filter tow strip by completely switching off the softener supply and dispensing, while the other filter tow strip is treated further normally.

How the particular FIGS. 1 . 2 . 3 and 5 1, first and second transport roller pairs 60 and 61 are arranged downstream of the application device 44, of which the first transport roller pair 60 is assigned to the first tow guide track 2 and the second transport roller pair 61 to the second tow guide track 3. Thus, the first filter tow 4 passes through the first pair of transport rollers 60 and the second filter tow 6, the second pair of transport rollers 61. Like the pairs of draw rollers 28, 29 and 30, 31 and the transport roller pairs 60 and 61 are driven separately by drives not shown, which is also not shown Control device to be regulated separately. In addition, the transport roller pairs 60, 61 in the illustrated embodiment in the same manner as the draw roller pairs 28 to 31 mounted on one side on the rear wall 32 of the machine frame 20, so that with respect to training and arrangement on the drafting roller pairs 28 to 31 relevant part of the description in conjunction with FIG. 4 is referenced.

By the transport roller pairs 60 and 61, the filter towers 4 and 6 are deflected to overlying deformation rollers 62 and 63, which in the illustrated embodiment at its periphery have a V-shaped cross-section, in particular the Figures 3 and 6 reveal. The deflection rollers 62 and 63 form a coaxially juxtaposed arrangement, which is mounted on one side on the rear wall 32 of the machine frame 20. How the particular FIGS. 6 and 7 can be seen, the hitherto flat spread filter tow strips 4 and 6 are formed by the forming rollers 62 and 63 to round tow strands 64 and 66.

The center distance of both tow guideways 2 and 3 is determined by the width of the spread filter tow strips 4 and 6 and is slightly larger than the sum of the widths of the filter tow strips 4 and 6. Usually the center distance of both tow guideways 2 and 3 is at least about 330 mm. For further processing in a double-strand machine, however, it is necessary to reduce the center distance between the round tow strands 64 and 66 to the deformation rollers 62 and 63 to the strand center distance of a double-strand machine, which is usually 38mm.

For this purpose, pairs of guide pulleys, not shown in the figures, can be provided which, after the deformation rollers 62, 63, can guide the now round tow ropes 64, 66 in any desired direction. Thus, a distraction of the towstring 64, 66 can be made in the direction strand. But such pulleys can be used to redirect the round towstring 64, 66 in different directions, for example, to serve physically separate from each other set up single-strand machines. By such a deflection can also twist the tow in the stretching zone or twist. Furthermore, it is conceivable, in view of the possibility of such a deflection, the above-described conditioning machine at an angle a downstream filter strand unit or a cigarette rod machine set up. Finally, it is also conceivable by such a deflection, to arrange the filter towballs 8, 9 at a different location relative to the machine frame 20.

Another possibility, the center distance between the two round Towsträngen 64, 66 to reduce, consists in the arrangement of two cranked inlet fingers 68 and 69, as provided in the illustrated embodiment, and in particular in the FIGS. 6 and 7 are shown recognizable. In the illustrated embodiment, the two round tow strands 64, 66 run slightly angled from the deformation rollers 62, 63 in the direction of the inlet fingers 68, 69. Since the guide rollers 62, 63 provide an obliquely running Towstrang 64, 66, the inlet fingers 68, 69 have a cranked Shape, so that there exiting tow strands 64, 66 are aligned again parallel to each other under the required reduced center distance. How the particular FIGS. 6 and 7 can be seen, the inlet fingers 68, 69 are hollow and have a tapering in the direction of the tow line 64, 66 shape. Furthermore, these figures show that the inlet fingers 68, 69 are double cranked, whereby a particularly gentle deflection of the towstring 64, 66 can be achieved

For better usability and maintenance, the inlet fingers 68, 69 from their in the FIGS. 6 and 7 be shown pivoting out of the operating position shown. For this purpose, in the illustrated embodiment, the inlet fingers 68, 69 attached to a carrier 70, as in FIG. 8 is shown. This carrier 70 is pivotally suspended via two mutually parallel pivot arms 72, 74 on a support member 76, which in turn on the machine frame 20 and preferably on the rear wall 32 (see. FIG. 1 ) is mounted. The two pivot arms 72, 74 form a parallelogram in that the pivot axis of the first pivot arm 72 connecting the first hinge 70 has the same distance to the pivot axis of the second pivot arm 74 with the holder 70 connecting the second joint as the pivot axis of the first Swivel arm 72 with the support member 76th connecting third hinge 79 to the pivot axis of the second pivot arm 74 to the support member 76 connecting the fourth joint 80. In the illustrated embodiment, said pivot axes extend at right angles to the direction of the Towstränge 64, 66. In this way, in the illustrated embodiment, the common support 70 for the two inlet fingers 68, 69 suspended from a pivotable in the direction Towstränge parallelogram, whereby the two inlet fingers 68, 69 in the direction opposite to the direction of the tow line 64, 66 and thus in the upstream direction according to arrow A of FIG. 8 from her to the FIGS. 6 to 8 shown operating position can be pivoted out.

Downstream of the machine described above is a filter strand unit, which is not shown in the figures. This filter strand unit has inter alia a wrapping device for wrapping the tow strands 64, 66 with wrapping paper and an adhesive application device for gluing the coated paper. It is known to use as adhesive either slow setting adhesive, in particular cold glue, or fast setting adhesive, in particular hot melt adhesive. Because of the different properties of these types of adhesives, it makes sense to form the adhesive applicator so that both types of adhesive can be applied. The advantage of such a measure is in particular that the fast-setting adhesive initially causes an immediate fixation of the wrapping paper, while the slow-setting adhesive leads to a permanent bond. Because a fast-setting adhesive such as hot melt adhesive has the disadvantageous property that the adhesive effect is lost after a long time. Therefore, especially at high processing speeds, the double application of slow and fast setting adhesives is recommended. In contrast, it is sufficient at low processing speeds, so in particular in partial load operation, which is possible in particular in the double-strand machine described above, only slowly setting adhesive.

Finally, two independent sampling devices may be provided for passing the manufactured products to two filter deliveries for two different cigarette production machines. Due to the arrangement of such separate removal devices, which are not shown in the figures, it is possible to use different and especially physically separately set up Filterstrangeinheiten or cigarette manufacturing machines. Preferably, such removal means may comprise a push-in drum or a transfer spreader.

Claims (13)

1. Device for the treatment of filter tow material for the production of filters for rod-shaped smoking articles, such as for example cigarettes, with filter tow provision means (7) for the provision of at least two filter tow strips (4, 6), at least two tow guideways (2, 3) by which in each tow guideway (2, 3) a filter tow strip (4, 6) is fed, and processing apparatus (24, 44) for processing the filter tow strips (4, 6), in which each tow guideway (2, 3) is assigned its own processing apparatus (26, 28, 30, 49; 27, 29, 31, 50) which can be controlled separately, wherein each processing apparatus has means (26, 28, 30, 49; 27, 29, 31, 50) for spreading, stretching and/or treating the filter tow material, characterised in that each tow guideway is assigned means for spreading the filter tow material and the means for spreading in each case form a unit in which they are arranged next to one another transverse to the direction of the tow guideways, wherein a corresponding number of means for spreading are provided according to the number of tow guideways, wherein all means for spreading form a unit and that the device has, above the filter tow provision means (7), a diverter element and tow spreading element (10) which is arranged at the upper end of a support arm (12) and has two same tow guides (14) lying next to one another and on which first spreader nozzles (16) are provided, and on a machine frame (20) second spreader nozzles (22) are arranged, along which the filter tow strips (4, 6) coming from the diverter element and tow spreading element (10) are fed and to which a two-track stretching apparatus (24) is connected.
2. Device according to claim 1, characterised in that the stretching apparatus (24) has first and second pairs of brake rolls (26, 27), first and second pairs of stretching rolls (28, 29) placed downstream behind the pairs of brake rolls (26, 27) and third and fourth pairs of stretching rolls (30, 31) placed downstream behind the first and second pairs of stretching rolls (28, 29).
3. Device according to claim 2, characterised in that the pairs of brake rolls (26, 27) can be actuated by separately assigned actuating elements with which the braking force exerted by the brake rolls (26, 27) on the filter tow strips (4, 6) can be influenced.
4. Device according to claim 3, characterised in that electric brakes are provided as actuating elements.
5. Device according to claim 3, characterised in that electric, hydraulic or pneumatic adjusting elements which adjust at least one roll of the two pairs of brake rolls (26, 27) transverse to its axis of rotation and influence the contact pressure of the brake rolls against one another, are provided.
6. Device according to one of claims 1 to 5, characterised in that each tow guideway (2,3) is assigned means (26, 28, 30, 49; 27, 29, 31, 50) for stretching and/or treating the filter tow material and the means for stretching and/or the means for treating in each case form a unit in which they are arranged next to one another transverse to the direction of the tow guideways (2, 3).
7. Device according to claim 6, characterised in that each means for stretching has a pair of rolls (28, 30; 29, 31) mounted on one side, driven by associated drive means. -
8. Device according to claim 7, characterised in that the pairs of rolls (28, 29, 30, 31) of the means for stretching, forming a unit, are mounted lying coaxially next to one another.
9. Device according to claim 8, characterised in that the first roll (29a) of the outer pair of rolls is mounted on a first shaft (34) and the first roll (28a) of the inner pair of rolls is mounted on a first pipe (36) through which the first shaft (34) extends.
10. Device according to claim 8 and 9, characterised in that the second roll of the outer pair of rolls is mounted on a second shaft and the second roll of the inner pair of rolls is mounted on a second pipe through which the second shaft extends.
11. Device according to at least one of the preceding claims, with a shaping apparatus (62, 63) for shaping two round filter tow strands (64, 66) from two filter tow strips (4, 6), characterised in that to reduce the distance between the filter tow strands (64, 66), two double-offset, conical inlet fingers (68, 69), through which in each case a filter tow strand (64, 66) is fed, are provided downstream after the shaping apparatus (62, 63).
12. Device according to claim 11, characterised in that the inlet fingers (68, 69) are attached to a common mount (70) which is suspended on a parallelogram frame (72, 74) that can be pivoted substantially in the direction of the filter tow strands (64, 66).
13. Device according to at least one of the preceding claims, with a shaping apparatus (62, 63) for shaping round filter tow strands (64, 66) from the filter tow strips (4, 6), characterised in that diverter means which preferably have at least one diverter roller, are provided downstream after the shaping apparatus (62, 63) to divert the round filter tow strands.

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