EP2255682A1 - Cutting tube - Google Patents

Abstract

The tube has a discharge side (9) arranged opposite to an inlet side (8). A groove (10) guides a tobacco strand during cutting. Groove walls (13,14) limited by the discharge and inlet sides are provided with passage spaces (15,16), respectively. The spaces are arranged transverse towards a longitudinal extension of a groove base (12). The spaces extend from its base ends (17, 19) up to its head ends (18, 20), which rest at the groove base, where the base ends are arranged at a free end (2) of the tube. One of the head ends exhibits a passage cross-section extending towards the discharge side.

Description

The present invention relates to a cutting tube for a strand of the tobacco processing industry having a mounting end and a free end opposite the mounting end and having a first end face, a second end face opposite the first end face, one substantially transverse to the first end face and the second Front side arranged inlet side, an opposite side of the inlet side arranged outlet side and with the strand cross at one end of the cutting tube for radial, alternately overlapping and releasing the strand open groove for guiding the strand during a cut, which extends from the first end side to the second end side extending groove bottom and one of the groove bottom outwardly extending, first groove wall and an opposite to the first groove wall and extending from the groove bottom outwardly extending second groove wall, wherein the first groove wall outside is limited from the exit side and is provided with a first passage gap and the second groove wall is bounded on the outside of the inlet side and provided with a second passage gap and the first passage gap and the second passage gap are arranged transversely to the longitudinal extent of the groove bottom.

Such cutting tubes are used for cutting strands in the manufacture of cigarettes and filters in order to initially divide endlessly produced fiber strands into sections of suitable length for use in further processing, which is also the case for strands made from filter segments.

In this case, first the respective material, such as tobacco fibers, filter fibers and / or filter segments transferred to wrapping paper, preformed together with wrapping paper into a strand, glued in an edge region of the wrapping paper and then closed the strand by overlapping the wrapping paper in the applied glue line, wherein a on average substantially circular strand arises.

In order to ensure a safe closing of the strand, a minimum amount of glue must be used, which is to bring to a rapid setting as a result of further processing steps, such as cutting. Not always can be avoided that glue residues from the so-called seam or the gluey overlap region of the wrapping paper still leaking and disturbing the strand closing downstream cutting process, especially when using hot glue or a higher amount of a water-containing glue and a particularly fast ongoing strand.

It can happen that glue deposits on the parts of the device involved in cutting, such as knives or strand guides or cutting tubes, which can lead to a deteriorated cutting quality of the sections up to a production interruption. In order to prevent this, manual cleaning processes are always necessary, which can only be done when the machine is at a standstill and thus limit the machine availability.

Rotary knife carriers with circumferentially distributed arranged cutting knives are common as cutting devices in the tobacco processing industry, among other things, which cooperate with a so-called multi-arm Tubenrad together.

The Tubenrad carries on arms attached, continuously moving cutting tubes, which approximate the strand in a cycle in its cyclical orbital movement, overlap it, lead for the period of knife penetration and release the strand after the cut again, both in the single-strand, and in the two strand method.

Working and mode of action of a cutting tube bearing, rotating Tubenrads are for example from the publications DE 21 38 834 . DE 23 45 063 . EP 1 905 316 A2 . EP 1 815 757 A1 such as WO 2005/089574 known.

Such a cutting tube is, as explained above, also inferior to the growth of glue residues.

Object of the present invention is to provide a cutting tube, which allows a low-maintenance operation and ensures optimum quality of cut.

This object is achieved by a Schneidtube with the features of claim 1.

In this way, depositing and growing glue residue on a cutting tube effectively and effectively prevented, at least the distance from one cleaning to the next cleaning at a consistently high quality cut can be significantly extended.

With such a cutting tube can be over five times longer operating time - without interrupting cleaning operations - achieve. In the presently proposed embodiment of the cutting tube, a knife entering the cutting gap of the cutting tube can be reliably guided even at high rpm and high cutting speed, and can take care of continuous cleaning of the cutting gap during the ongoing process or during ongoing production. This is made possible by the configuration of the cutting gap with passage gaps in the course of the entry of the knife in the direction of the outlet of the knife. While in a channel-like narrow portion of the cutting gap, the cyclically occurring and oscillating blade is precisely guided, the radially outer cutting edge when passing through the cutting gap or the passage gaps, the approximately conically widening trained cutting gap or the passage gaps continuously clean , Corresponding to the passage of the blade of the cutting gap is formed at its in the cutting tube inside the head end approximately conically widening to the exit side. In this case, it is particularly easy for the entering knife cutting edge to dissipate any glue residues adhering to inner surfaces of the cutting tube to the outside, since a discharge resistance in the region opening towards the exit side in width and / or height is markedly reduced in this area.

Advantageous embodiments and further developments of the cutting tube can be found in the dependent claims, as well as the description of an embodiment of a cutting tube.

In addition to a self-cleaning effect ensures the proposed Schneidtube by the special design of the cutting gap or the passage column a Minimal contact surface for the attachment of glue residues and still ensures an optimal, low-friction blade guide. Regardless of the above-described and hereinafter described self-cleaning effect, the proposed cutting tube according to an embodiment of claim 10 and optionally specified in the claims 11 to 14 developments an embodiment which preventively counteracts settling or attaching glue residues by a minimized guide surface for an entering knife.

The opposite in the cutting gap of the cutting tube guide surfaces are spaced so that when setting the Schneidtubenausrichtung for precise operation engagement of a knife at standstill of the machine a playful passage of the blade is enabled and that in the case of operation as smooth as possible passage with simultaneous support function in knife vibrations is guaranteed.

The above-explained preventive effect by specially plateau-like configured guide surfaces in the cutting gap can also be set independently of the self-cleaning effect explained above, so that this aspect has an independently inventive rank. Therefore, a cutting tube having this preventive effect does not have to have an extension of the passage cross section in the direction of the exit side as provided in claim 1, so that the back-reference to claims 1 to 9 is to be understood in connection with a combination of the two effects mentioned above , Such a cutting tube solves the above-mentioned object, without the aforementioned extension of the passage cross-section according to claim 1.

Figur 1

zeigt eine schematische Draufsicht auf die Austrittsseite der Schneidtube.

Figur 2

zeigt eine schematische Draufsicht auf die Eintrittsseite der Schneidtube aus Figur 1.

Figur 3

zeigt einen schematischen Schnitt durch die Schneidtube entlang der Schnittlinie A-A in Figur 2.

Figur 4

zeigt eine schematische, perspektivische Schnittdarstellung der Schneidtube, in einer vergrößerten Darstellung.

The present invention will be explained in more detail below with reference to an embodiment of a cutting tube shown in the figures.

FIG. 1

shows a schematic plan view of the exit side of the cutting tube.

FIG. 2

shows a schematic plan view of the inlet side of the cutting tube FIG. 1 ,

FIG. 3

shows a schematic section through the Schneidtube along the section line AA in FIG. 2 ,

FIG. 4

shows a schematic, perspective sectional view of the cutting tube, in an enlarged view.

The in the FIGS. 1 to 4 shown cutting tube is constructed substantially in much the same as a double fork and comprises two mutually transversely arranged guide forks, one of which leads the strand 11 during its section and the other a knife 21 during the strand cut.

The cutting tube comprises a fastening end 1 and a fastening end 1 opposite, free end 2, as in particular from FIG. 3 is apparent.

The attachment end 1 is provided with a rectangular in section upwardly open attachment groove for receiving a molded part, not shown, of a support arm, also not shown. The attachment end 1 is provided with a parallel to the aforementioned groove extending, cylindrical bore 3 for receiving a clamping bolt, not shown, which has two threaded holes for receiving fastening screws. The groove bottom of the aforementioned mounting groove has two through holes 4 for the mounting screws, one of which in FIG. 4 (upper part) is shown.

The Schneidtube is made of powder metallurgical steel, has a high hardness and is secured via the above-described, clamping attachment by the clamping bolt, the threaded holes, the mounting screws and the through holes in a material-optimized manner reliably releasably and adjustably attached to the support arm. As in FIG. 4 are shown in alignment with the aforementioned through-holes 4 each have a blind bore 5 opposite to the groove bottom of the mounting groove on the circumference of the bore for receiving the clamping bolt. The attachment end 1 can be designed differently in a modification of the present embodiment, for example, as is apparent from the aforementioned publications.

The cutting tube has a first end face 6 and one of the first end face 6, opposite the second end face 7. The first end face 6 and the second end face 7 each have an inwardly angled path towards the free end 2 (cf. Figures 1 and 2 ).

Transverse to the first end face 6 and the second end face 7 (see Figures 1 and 2 ) is an entrance side 8, which in a plan view in FIG. 2 is shown, and the inlet side 8 opposite a discharge side 9, which in a plan view in FIG. 1 is shown arranged.

At the free end 2 of the cutting tube, an outwardly open groove 10 is provided for guiding a strand 11 during a cut. With the groove 10, the strand 11 is radial, alternately overlapped and released when the cutting tube is driven cyclically circumferentially on her arm, wherein it approaches the strand 11, it overlaps, supports, then releases again and moves away from it.

The groove 10 has a groove bottom 12 extending from the first end face 6 to the second end face 7. From the groove base 12 extends outwardly toward the free end 2 of the cutting tube, a first groove wall 13 and an outwardly towards the free end 2 of the cutting groove second groove wall 14. The first groove wall 13 is bounded on the outside of the outlet side 9 and is provided with a first passage gap 15. The second groove wall 14 is bounded on the outside by the inlet side 8 and is provided with a second passage gap 16.

The first passage gap 15 and the second passage gap 16 are each arranged transversely to the longitudinal extent of the groove base 12. By this arrangement, a cut is ensured in which the end faces of the cut strand sections aligned exactly transversely to the longitudinal axis of the strand and are flat. The first passage gap 15 extends from its foot end 17 located at the free end 2 to its head end 18 located above the groove bottom 12.

The second passage gap 16 extends from its foot end 19 located at the free end 2 to its head end 20 located above the groove bottom 12.

The longitudinal extension of the first passage gap 15 and of the second passage gap 16 or the first groove wall 13 and the second groove wall 14 are dimensioned such that a in FIG. 3 schematically shown partially broken knife 21 at the beginning of its contact with the strand 11 is already performed in both passage fins 15, 16 and the first groove wall 13 and the second groove wall 14 in a cutting gap thus formed. This ensures a particularly precise cut.

Is modified in a modification of the illustrated embodiment, the respective longitudinal extent of the passage column 15, 16 or the two passage gaps 15, 16 and the respective groove wall 13, 14 such that at a cut start of the strand 11, the knife 21 only in one of the passage column 15, 16 is performed, then results in a reduced - but also still usable - cut quality.

The head end 20 of the second passage gap 16 has a passage cross-section widening in the direction of the outlet side 9. The head end 18 of the first passage gap 15 has a passage cross-section widening in the direction of the outlet side 9.

In a modification of the illustrated embodiment may also be provided the head end 20 with an at least partially consistent, non-expanding passage cross-section and the head end 18 to be provided with a widening in the direction of the exit side 9 toward passage cross-section to achieve a sufficient self-cleaning effect.

In the in the FIGS. 1 to 4 illustrated embodiment, the first groove wall 13 and the second groove wall 14 are of equal length. They extend for the same length to the approximately semicircular groove base 12 in section, then to the free end 2, with respective formation of an end-side phase (cf. Figures 3 and 4 ).

The phases of the two mutually facing groove walls 13, 14 form a diverging to the free end 2 portion of the groove 10, with which the strand 11 is gently overlapped.

The first passage gap 15 is designed to be longer than the second passage gap 16, relative to its respective extent from its respective foot end 17, 19 located at the free end 2 to its respective head end 18, 20 located above the groove base 12.

Even in the case of uneven groove walls 13, 14, the first passage gap 15 is formed longer than the second passage gap 16, but with respect to their respective extent from the groove base 12 to their respective lying above the groove bottom 12 head 18, 20th

The passage cross-section of each passage gap 15, 16 is widening in the direction of the longitudinal extent of the respective passage gap 15, 16 towards the attachment end 1 of the cutting tube in the region of the head ends 18, 20. Different expressed in terms of their respective width or clear width over the bottom of the groove 12 at least partially. Up to the bottom of the groove 12 and a certain distance beyond until the beginning of the head ends 18, 20 each have a narrow parallel gap, in particular with a gap width of about 0.3 mm, depending on the width of the blade 21, taking into account a desired game.

The first passage gap 15 and the second passage gap 16 are formed with their respective head end 18, 20 from the outlet side 9 toward the inlet side 8 or in the opposite direction seen in each other transiently (see Figures 3 and 4 ). In this way creates a continuous cutting gap, as explained above.

The cutting tube forms a passage 22 extending from the inlet side 8 in the region of the head end 20 towards the outlet side 9 in the region of the head end 18 and widening for the knife 21. The passage space 22 has a substantially teardrop-shaped contour in section. The teardrop-shaped contour is formed by a partial cone lateral surface 23 extending from the inlet side 8 to the outlet side 9 and peripheral, respectively adjacent, planar through-phases 24 on the partial cone lateral surface 23. The formation of the aforementioned contour is particularly detailed in FIG FIG. 4 for clarity in FIG. 3 a simplified representation of this contour is reproduced. In FIG. 4 the aforementioned transition from the partial cone surface 23 to the passage phase is indicated by a solid line.

The passage space 22 has an upper boundary line 25 extending from the inlet side 8 to the outlet side 9 (in FIG FIG. 3 from right to left and in FIG. 4 running from left to right), which are opposite to the horizontal is arranged rising. The upper boundary line 25 forms the line of the partial cone lateral surface 23, on which the - viewed in section - furthest from the groove base 12 or the free end 2 - depending on the reference point - remote points of the passage space 22 are. The angle α of the increase is in the illustrated embodiment in about 2 °. He should hardly fall below an angle of 1 ° in modifications of the embodiment.

The passage space 22 has two extending from the inlet side 8 toward the outlet side 9 lower boundary lines 26 (in FIG. 3 from right to left and in FIG. 4 running from left to right), which are arranged in each case falling relative to the horizontal. The lower boundary lines 26 are each formed by a passage phase 24 and a respective guide plateau 27 provided on the inside in the first passage gap 15 and in the second passage gap 16. The two lower boundary lines 26 are each inclined in the illustrated embodiment with respect to the horizontal. The angle β of the inclination is in the illustrated embodiment in about 11 °. He should hardly fall below an angle of 1 ° in modifications of the embodiment.

On the entry side 8 is, in particular FIG. 2 in plan view and FIG. 3 shows in section, a the second passage gap 16 u-fömig encompassing, projecting from the inlet side 8 outwardly and partially on the outside of the second groove wall 14 extending paragraph 28 is provided. By the shoulder 28, the second groove wall 14 and lying over the second groove wall 14 portion of the cutting tube in the region of the second passage gap 16 is increased in wall thickness.

As already explained above, both the first passage gap 15, as also the second passage gap 16 each have a guide plateau 27. Each guide plateau 27 is flat and formed in the respective passage gap 15, 16 protruding. Each Führungsplateau 27 extends from the inlet side 8 to the exit side 9 in a first direction. In a second direction, each guide plateau 27 extends from the respective lower boundary line 26 toward the free end 2 of the cutting tube. The first direction is transverse to the above-mentioned second direction.

The respective guide plateau 27 is bounded on the inlet side by an entry phase 29, which is arranged on the inlet side 8 extending into the second passage gap 16 and formed in part by the second groove wall 14 and partly by a extending up to the head end 20 section of the cutting tube becomes.

The respective guide plateau 27 is bounded on the outlet side by an outlet phase 30 which is arranged extending on the outlet side 9 in the first passage gap 15 and formed in part by the first groove wall 13 and partly by a section of the cutting tube extending into the head end 18 becomes.

The guide plateau 27 is thus surrounded by adjacent surfaces, which seen from the guide plateau from a sloping course.

In the embodiment described and explained above, the cutting tube is integrally formed. In a modification of the embodiment described above, however, a multi-piece design of the cutting tube is possible.

For example, a modification of the above embodiment take place by a two-piece design of a Schneidtube by two parts which are connected to one another by means of fastening means. In such a modification, it is particularly advantageous to provide a dividing plane which extends through the planes of symmetry of the two passage gaps 15, 16, for example along the section line AA according to FIG FIG. 2 ,

In addition to the above description of the embodiment is to be noted that a sole design of a cutting tube with a minimized in terms of its support or contact surface guide plateau 27, it is already possible to reduce occurring glue growths and deposits to a minimum. Alone already by this configuration, a life of such a cutting tube can already be significantly extended. Should there be glue deposits despite such a minimized support or contact surface, they can be eliminated by the proposed design of the passage gaps 15, 16 or their head ends 18, 20 in the form of an ongoing self-cleaning effect.

In addition to the above-described and explained embodiments of the cutting tube is still with a view FIG. 4 It should be noted that the design of the groove bottom 12 also leads to an optimized strand guide. In the in FIG. 4 shown view of an embodiment of a cutting tube of the groove base 12 is formed by two in the longitudinal extension of the groove bottom 12 consecutive sections. In approximately at the level of the first passage gap 15, a first section is provided, which has a cylindrical partial jacket surface. A second section, which extends in the direction of the second end face 7 and has a partial cone jacket, is then provided on this cylindrical partial jacket surface. Expressed differently, an inlet region for the strand 11, which is a gentle one, is again formed by this second section Absorption of the strand 11 ensured. The aforementioned first section in turn ensures precise guidance of the strand 11 immediately near the cut.

With the here proposed and explained embodiment of a cutting tube a precise cut of the strand 11 over extremely long, maintenance-free production intervals can be achieved. The proposed cutting tube allows the use of otherwise difficult to handle glue types. reference numeral description 1 attachment end 2 free end 3 cylindrical bore 4 Through bores 5 blind holes 6 first end face 7 second end face 8th entry page 9 exit side 10 groove 11 strand 12 groove base 13 first groove wall 14 second groove wall 15 first passage gap 16 second passage gap 17 Foot end, first passage gap 18 Headboard, first passageway 19 Foot end, second passage gap 20 Head end, second passage gap 21 knife 22 Passage space 23 Part conical surface 24 Through phases 25 upper limit line 26 lower boundary line 27 leadership plateau 28 Paragraph, U-shaped 29 run-in phase 30 phasing 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

Claims (15)

Cutting tube for a strand (11) of the tobacco-processing industry with a fastening end (1) and the free end (2) opposite the fastening end (1), and with a first end face (6) opposite one of the first end face (6) second end face (7), a substantially transversely to the first end face (6) and the second end face (7) arranged inlet side (8), an opposite side of the inlet (8) arranged outlet side (9) and with a strand (11) cross-over at the free end (2) for radially, alternately overlapping and releasing the strand (11) open groove (10) for guiding the strand (11) during a cut, which extends from the first end face (6) to the second End side (7) extending groove bottom (12) and one of the groove base (12) outwardly extending first groove wall (13) and an opposite to the first groove wall (13) and from the groove bottom (12) outwardly extending second groove wall (14), wherein the first groove wall (13) on the outside of the outlet side (9) is limited and provided with a first passage gap (15) and the second groove wall (14) on the outside of the inlet side (8) is limited and is provided with a second passage gap (16) and the first passage gap (15) and the second passage gap (16) are arranged transversely to the longitudinal extension of the groove bottom (12), wherein the first passage gap (15) from its at the free end (2 ) lying foot end (17) to its over the groove bottom (12) lying head end (18) and the second passage gap (16) from its at the free end (2) located foot end (19) to its over the groove bottom (12) lying head end (20) and the head end (20) of the second passage gap (16) and / or the head end (18) of the first passage gap (15) has a in the direction of the outlet side (9) widening passage cross-section. Cutting tube according to claim 1, characterized in that the first passage gap (15) is formed longer than the second passage gap (16), based on their respective extension of their at the free end (2) of the Schneidtube foot end (17, 19) to to their respective over the groove base (12) lying head end (18, 20) in the case of equal groove walls (13, 14), in the case of uneven groove walls (13, 14) based on their respective extent starting from the groove bottom (12) to their respective over the groove bottom (12) lying head end (18, 20). Cutting tube according to claim 1, characterized in that the passage cross-section in the direction of the longitudinal extension of a passage gap (15, 16) is widening, in particular towards the attachment end (1). Cutting tube according to one of claims 1 to 3, characterized in that the first passage gap (15) and the second passage gap (16) with their respective head end (18, 20) from the outlet side (9) to the inlet side (8) into one another are formed. Cutting tube according to one of claims 1 to 4, characterized in that one of the inlet side (8) in the region of the head end (20) of the second passage gap (16) towards the outlet side (9) in the region of the head end (18) of the first Passage gap (15) extending and expanding passage space (22) is formed. Cutting tube according to claim 5, characterized in that the passage space (22) in section has a substantially teardrop-shaped contour. Cutting tube according to claim 5 or 6, characterized in that the course of the from the inlet side (8) to the outlet side (9) extending upper boundary line (25) of the passage space (22) is increasing, relative to the horizontal, in particular with a Angle α of more than 1 °. Cutting tube according to one of claims 5 to 7, characterized in that the course of a, from the inlet side (8) to the outlet side (9) extending lower boundary line (26) of the passage space (22) is inclined, relative to the horizontal, in particular with an angle β of more than 1 °. Cutting tube according to one of claims 1 to 8, characterized in that on the inlet side (8) the second passage gap (16) U-shaped embracing, from the inlet side (8) outwardly projecting and partially outside on the second groove wall (14 ) extending paragraph (28) is provided. Cutting tube according to one of claims 1 to 9, characterized in that the first passage gap (15) and / or the second passage gap on the inside have an at least partially planar and projecting guide plateau (27). Cutting tube according to claim 10, characterized in that the guide plateau (27) on the inlet side by an inlet phase (29) is limited, which in particular at the inlet side (8) is arranged to extend into the second passage gap (16) and partly from the second groove wall (14) and is formed in part by a section extending into the head end (20). Cutting tube according to claim 10 or 11, characterized in that the guide plateau (27) is delimited on the outlet side by an outlet phase (30), which is arranged extending in particular at the outlet side (9) in the first passage gap (15) and partly from the first groove wall 13 and partly from a to the head end (18) extending portion is formed. Cutting tube according to one of claims 10 to 12, characterized in that the guide plateau (27) in the direction of the head ends (18, 20) by an inside in the respective passage gap (15, 16) provided passage phase (24) is limited, which in particular extends from the inlet side (8) to the outlet side (9). Cutting tube according to claim 13, characterized in that the passage phase (24) in the direction of the inlet side (8) towards the outlet side (9) increases in width and in particular is flat. Cutting tube according to one of claims 1 to 14, characterized in that it is formed in one piece or several pieces, in particular in two pieces two parts, which are connectable to each other by means of fastening means, with a through the two passage gaps (15, 16) extending graduation plane.

Images