EP0015386B1 - Device for wrapping articles, especially blocks of cigarettes - Google Patents

Description

The invention relates to a device for wrapping objects, in particular cigarette groups, in a blank made of packaging material, this at least on two lateral edge areas by endless conveyors in the form of two suction disks which are rotatably mounted next to the movement path of the objects in a plane transverse to the transport direction of the Held object and can be put around the object by pulling the suction disks out of a U-shape.

The subject of the present invention is the packaging of objects which are particularly sensitive to mechanical stresses, e.g. Groups of cigarettes intended for one pack of cigarettes. The cigarettes to be packaged are wrapped in groups in such a way that a blank held in one plane transverse to the transport path of the cigarettes is placed in a U-shape by the relative movement of the cigarette group around an end face of the group lying forward in the transport direction.

The main aim is to keep the cut in question in an exact relative position and, despite the high performance of the machine, that is to say despite the high conveying speed of the cigarette group, to place it precisely and wrinkle-free. This support should also be provided for critical packaging material which, due to its low rigidity, cannot be processed properly without constant positive guidance.

Finally, a continuous way of working should also be guaranteed. Because only a continuous working method allows the high performance of a packaging machine that is required today.

DE-C-575 899 discloses a device of the type mentioned at the outset, this device also being suitable for processing, for example, thin and therefore critical packaging material. However, it has been shown that in the known device the individual casings of the cigarette group are exposed to high mechanical loads, especially during the phase of the takeover of the blank by the front end of the cigarette group and when the blank is subsequently pulled off the suction discs. During this initial phase, the holding force exerted on the blank by the suction disks is inevitably greatest. However, this problem does not play a major role in the known solution, since the cigarette groups are already packaged before being wrapped, and the loads that occur can thus be absorbed without further ado.

DE-C-575 899 describes a device on cigarette packaging machines with which the cigarettes to be packaged are guided through a reciprocating mouthpiece-like guide against a blank of packaging material that is vertically downward in the path of movement of the packaged Cigarettes hanging. In order to achieve a complete buckling of the packaging film or breakage of the broken edges of the packaging blank with the help of the guide mouthpiece before the cigarettes to be packaged come into contact with the blank, the front side of the mouthpiece protrudes slightly above the front end face of the cigarettes to be wrapped. The mouthpiece therefore comes into contact with the blank made of packaging material before the cigarettes to be packaged. DE-C-575899 therefore describes a classic mouthpiece as has been used in the packaging industry for decades. This mouthpiece offers edge protection for the cigarettes to be packaged. The mechanical load on the cigarettes to be packaged due to the cutting from packaging material is therefore correspondingly low in the known solution. It is disadvantageous, however, that there is no measure for keeping the cut blank ready in an exact position relative to the cigarettes to be packaged. After the blank has been cut off by appropriate knives, it slides down in an essentially uncontrolled manner through a vertical guide arranged above the movement path of the cigarette group. It is therefore not guaranteed in the known solution according to DE-C-575 899 that the blank is always gripped in the center by the mouthpiece or by the cigarette group.

If, in the known solution according to DE-C-575 899, a thin and wrinkle-prone cellophane film was used as packaging material instead of a relatively rigid metal foil, this would be due to the missing fixation of the cut blank for capturing it by the mouthpiece or during the phase of The cut is taken over by the front end of the cigarettes to be packed, the increased risk of wrinkles. This risk of wrinkling would be particularly high at the higher working speeds that are required today.

Finally, it cannot be seen that continuous operation is possible with the device described in DE-C-575899. Rather, it must be assumed that the known device only allows intermittent operation.

From DE-A-16 36 224 a device for cutting off desired lengths from an uninterrupted web of wrapping material is generally known, wherein a rotating knife is arranged in a suction drum that receives the web, which together with a fixed knife outside the suction drum works. The cut blank is then picked up by an endless conveyor belt system and conveyed into the movement path of cigarette packs to be wrapped. A fixation of the cut blanks in the movement path of the objects to be packaged and a mouthpiece protecting the objects to be packaged are completely lacking in the known solution, so that an exact and wrinkle-free laying down of the cut blanks around the objects to be packaged is not guaranteed. This applies in particular when critical packaging material is to be used, for example a thin and crease-prone cellophane film.

Based on the known prior art, the present invention has for its object to provide a device of the type mentioned, which allows wrinkle-free wrapping of objects sensitive to mechanical loads, especially unpacked groups of cigarettes, even then , if crinkle-sensitive material is used as packaging material.

This object is achieved in that the cigarette group is accommodated in a mouthpiece arranged between the suction disks in the plane of the movement path of the cigarette group, which ends flush on the front side of the cigarette group in the transport direction or slightly protrudes and through which the blank can be lifted off or detached from the suction disks at least during an initial phase of the wrapping process.

In the solution according to the invention, the cigarette group is temporarily accommodated in the mouthpiece, which protects the cigarette group against the mechanical stresses caused by the cut taken over by the suction disks. At the same time, the suction discs ensure that the blanks are always kept in an exact relative position, so that exact and wrinkle-free envelopes are guaranteed even at high working speeds. It has been shown that this also applies to critical packaging material which, due to its low rigidity, cannot be processed properly without constant positive guidance. Finally, continuous operation is possible with the device designed according to the invention, as a result of which higher working speeds can be achieved.

In order to achieve fold edges with the U-fold without any problems, the mouthpiece preferably enclosing the cigarette group practically completely in cross section is provided with sharpened edges on the front receiving the blank.

According to a further proposal of the invention, the suction disks have a plurality of groups of suction bores distributed along the circumference. These only capture the cut in certain critical areas. After the cut has been taken over by the mouthpiece and subsequently by the cigarette group, the suction bores are switched off and vented from the negative pressure sources, so that the cut can subsequently be put around the cigarette group without any retention force by the suction disks, while the latter is in a subsequent mouthpiece-like one Recording, namely entering a packaging line.

The construction according to the invention enables the blanks to be fed very precisely at a high working speed. Nevertheless, the cut is handed over to the cigarette groups gently, without undue stress on them.

Further features of the invention relate to the structural design of the mouthpiece and to the units arranged upstream of the suction disks for the production of the blanks by severing them from a continuous web and for feeding them to the suction disks.

• Fig. 1 den hier interessierenden Teil der Vorrichtung in schematischer Seitenansicht bzw. im Längsschnitt,
• Fig. 2 einen horizontal und vertikal verlaufenden Querschnitt 11-11 in Fig. 1,
• Fig. 3 Einzelheiten der Vorrichtung in einem Schnitt entsprechend Fig. 1 bei veränderter Relativstellung und in vergrößertem Maßstab,
• Fig. 4 eine Darstellung entsprechend Fig. 1 bei nochmals veränderter Relativstellung.

A preferred embodiment of the invention is explained below with reference to the drawings. Show it :

• 1 the part of the device of interest here in a schematic side view or in longitudinal section,
• 2 is a horizontal and vertical cross section 11-11 in Fig. 1,
• 3 details of the device in a section corresponding to FIG. 1 with changed relative position and on an enlarged scale,
• 4 shows a representation corresponding to FIG. 1 with the relative position again changed.

The present exemplary embodiment relates to the wrapping of cigarette groups 10. These are continuously fed at intervals from one another and in the longitudinal direction of the cigarettes on a packaging web 11. This is designed so that the as yet unpacked cigarette groups 10 are kept in the group formation. For this purpose, the packing track is designed with an upper wall, lower wall and side boundaries.

The cigarette groups 10 are transported here by an endless conveyor in the form of a chain conveyor 12. The catches 13 enter the packaging line 11. For this purpose, the lower wall is formed with a longitudinal slot for the passage of a web of the drivers 13.

The cigarette group 10 is to be wrapped in a blank 14 in such a way that it is placed in a U-shape around the front end 15 in the transport direction. In addition, laterally projecting side tabs of the blank 14 are pre-folded in the region of the end face 15.

The blanks 14 are separated from a continuous web 16 of packaging material by a separating device 17. One equipped with suction bores and one with a sub knife roller 18 pressurized transfers the cut blanks 14 to an endless conveyor in the form of two coaxially spaced suction disks 19 and 20. These are provided along their circumferential surface 21 receiving the blank 14 with suction openings, namely groups of suction bores 22 and 23a, 23b or suction slits . Negative pressure is applied to these with special control, such that the blank 14 is held by the suction disks 19, 20 during its conveyance, but is then released, namely when it is taken over by the cigarette group 10.

The suction disks 19, 20 are arranged at such a distance from one another that the cigarette group 10 can be passed between the suction disks 19 and 20. On the side opposite the entrance, the blank 14 is kept ready in such a way that in the present case a central area of the same system on the end face 15 of the cigarette group 10 is obtained. By further transporting them - carried out by the chain conveyor 12 - the cigarette group 10 with the blank 14 is inserted into a further packaging web 24. This fixes the blank 14 in the U-shaped arrangement on the cigarette group 10 with the top wall 25 and the bottom wall 26. In addition, the packing web 24 is equipped with lateral guide means, namely folding thumbs 27 and 28. These come on the side surfaces of the cigarette group 10 to the system and also have the function of folding the protruding side tab against the cigarette group 10.

During the decisive phase, the cigarette group 10 is received in a mouthpiece 29. In the present case, this is designed as a housing which is open at both ends, that is to say with a top wall 30. Bottom wall 31 and side walls 32. 33. The cross section of the mouthpiece 29 is chosen such that the unwrapped Z ^: Ttten group 10 is fixed while observing the cigarette's position.

The mouthpiece 29 is slidably mounted with an exact fit between the suction disks 19 and 20, in the present case exactly in the middle position with respect to the suction disks 19, 20. The passage of the mouthpiece 29 runs horizontally, namely in the height or in the extension of the packing web 11 The side walls 32, 33 of the mouthpiece 29 are thin-walled in order to keep the distance between the cigarette group 10 and the suction disks 19, 20 small.

The cigarette group 10 is introduced via a rear inlet opening 34 with a funnel-shaped design into the mouthpiece 29, namely through the driver 13 of the chain conveyor 12. The bottom wall 31 of the mouthpiece 29 is for this purpose with a slot 35 in the longitudinal direction for the passage the driver 13 or the webs of the same.

The mouthpiece 29 can be moved back and forth in the conveying direction of the cigarette group 10. For this purpose, the mouthpiece 29 with support members 36 is slidably mounted on guide rods 38, which in the present case are arranged laterally outside of the packaging path 11. The mouthpiece 29 can be driven by a crank mechanism.

The cigarette group 10 can also be moved relative to it during the movement stroke of the mouthpiece 29 in the conveying direction thereof. The movements are coordinated so that the mouthpiece 29 moved between the suction disks 19, 20 with a sharpened front edge 40 while the cigarette group 10 is still set back detects the blank 14 fixed by the suction disks 19, 20 and subtracts it from the latter when it moves further. 1 shows the moment when the blank 14 is taken over by the front edge 40 of the mouthpiece 29.

The transfer of the blank 14 to the cigarette group 10 and the U-shaped wrapping thereof result from FIGS. 3, 1 and 4 in successive phases. Fig. 3 shows the starting position, in which the blank 14 is still in the phase of transport to the end position. The mouthpiece 29 is shown in the retracted position. Only when the blank 14 has reached a relative position in relation to the mouthpiece 29 or packing web 11, which corresponds approximately to that shown in FIG. 1, is it taken over by the mouthpiece 29 emerging from the area of the suction disks 19, 20 with the leading edge 40 the cigarette group 10 has been moved relative to the mouthpiece 29 in such a way that the cut 14, which has already been U-shaped, is taken over relatively shortly thereafter by the cigarette group 10 emerging from the mouthpiece 29. The part of the blank 14 which surrounds the front edge 40 of the mouthpiece 29 has already been introduced into the packaging web 24. For this purpose, the top wall 25 and bottom wall 26 are provided with a sharpened, funnel-shaped inlet edge 41. In the exemplary embodiment shown, the aforementioned inlet edges 41 are arranged in the immediate vicinity of the circumference of the suction disks 19, 20, so that the mouthpiece 29 executes a relatively narrow stroke. The folded thumbs 27 and 28 rounded at the free end are set back in relation to the leading edges 41 in the present case. However, it is alternatively also possible to design the folding thumbs 27, 28 such that they can move - with a larger cut between the circumference of the suction disks 19, 20 on the one hand and the packing web 24 on the other - against the cigarette group 10 with the blank 14.

Special control of the fixation of the blank 14 on the suction disks 19 and 20 ensures that, on the one hand, an exact relative position of the blank 14 is maintained, but on the other hand, this without an inhibiting back holding forces can be taken over. For this purpose, the suction disks 19, 20 are provided with the first group of suction bores 22 - for example a row of suction bores lying side by side in the axial direction. This is arranged in such a way that an area of the blank 14 lying forward in the transport direction is taken over and fixed. The aforementioned suction bores 22 are acted upon by a ring line 42 which extend over a wide circumferential area of the suction disks 19, 20. During this phase, namely until a vent hole 43 is reached, the blank 14 is fixed by the suction holes 22. It is possible to release the area in front of the blank 14 before the end position is reached and it is taken over by the mouthpiece 29, so that the relevant part of the blank 14 sags downward in the sense of FIG. 1.

The two other groups of suction bores 23a and 23b are arranged at a distance from one another and at a distance from the suction bores 22 such that when the blank 14 is reached they are in the position for transfer to the mouthpiece 29 on both sides thereof (position according to FIG. 1). The blank 14 is accordingly fixed during the takeover phase by the mouthpiece 29 and the cigarette group 10 directly on both sides of the mouthpiece 29, and only for a moment of the uninterrupted movement. The suction bores 23a lying in front in the circumferential direction are then in the region of a further ventilation bore 44, as a result of which the negative pressure in both groups of suction bores 23a, 23b drops, as a result of a connecting channel 45 between the suction bores 23a, 23b. The blank 14 is therefore completely free of restraining forces on the circumference of the suction disks 19, 20 at this moment.

As can be seen from FIG. 2, the ring line 42 and the ventilation bores 43 and 44 are formed by stationary, that is to say non-rotatable, air control rings 46 which are pressed against the outer surfaces of the suction disks 19, 20 by springs 47. The suction air is supplied with negative pressure via a central suction line 48 in a drive shaft 49 of the suction disks 19, 20 and via transversely or radially directed connecting lines 50, 51. The air control rings 46 are fixed by a rotation lock 52 to outer, fixed bearing cheeks 53.

From the ring line 42, axially parallel air channels 54, 55 and 56 lead to the suction bores 22 and 23a, 23b. As can be seen from the drawings, the air channels 54 and 55 for the suction bore 23a, 23b on the one hand and the air channel 56 for the suction bore 22 on the other are on different (imaginary) arcs. The shape of the ring line 42 is adapted accordingly and in the area of the takeover of the blank 14 - in FIGS. 1, 3 and 4 above - with a larger cross section in the radial direction. In this area, the suction bores 22 and the suction bores 23a, 23b are supplied by the common ring line 42. Outside the area of the widened cross section of the ring line 42, the suction bores 23a, 23b are separated from the vacuum source.

The separating device 17 is also designed in a special way. The continuously rotating knife roller 18 is equipped with two separating knives 57 and 58. The separating knife 57, which protrudes beyond the circumference of the knife roller 18, interacts with a stationary counter knife 59. The separating cut for separating the blank 14 from the subsequent web 16 is carried out in this area.

In contrast, the separating knife 58 is somewhat reset. It works together with a correspondingly protruding counterpart, namely in the present case with a counter roller 60 which rotates through a carrier roller 61. The movements of the knife roller 18 and the carrier roller 61 are coordinated. The rotatable counter roller 60 protrudes beyond the circumference of the carrier roller 61, which in turn is at a distance from the circumference of the knife roller 18, in such a way that the projecting separating knife 57 can run past the circumference of the carrier roller 61 with a sufficient distance. The separating knife 58 and counter roller 60 perform a perforation cut in the blank 14, specifically to delimit a flap. The relative position is such that first the separating cut in the area of the separating knife 57 and counter knife 59 and then the perforation cut in the area of the separating knife 58 and the counter roller 60 are carried out.

In order to always transport the incoming web 16 or the blank 14 without creases, there are white speed differences. In this sense, the knife roller 18 rotates at a somewhat higher speed than the feed speed of the web 16. The suction rollers 19, 20 rotating at the same speed have a somewhat lower speed than the cigarette group 10.

The knife roller 18 is provided with suction bores 62 and 63, the air channels 64 and 65 of which likewise lie on different orbits and are therefore acted upon differently by a common ring line 66 formed with a non-uniform cross section. Due to the larger number of suction bores 62 distributed along the circumference, the blanks 14 or the web 16 are only fixed along a relatively small circumferential section - predetermined by a radially inward widening of the cross section of the ring line 66 - while a single group of bores 63 each fixed a front area of the web 16 or the blank 14 from the takeover to the delivery to the suction disks 19, 20. The end of this holding force is in the lower one Area formed vent hole 67 determined. The construction and design and supply of the suction bores 62 and 63 are carried out in an analogous manner to the suction disks 19, 20.

Claims (13)

1. Apparatus for wrapping articles, particularly cigarette groups (10) in a packing material blank (14), the latter being held in at least two lateral edge areas by endless conveyors in the form of two suction disks (19, 20), in each case rotatably mounted alongside the path of movement of articles (10) in a plane at right angles to the conveying direction of article (10) and, on removal from suction disks (19, 20), wrappable in U-shaped manner about the article (10), characterized in that the cigarette group (10) is received in a mouthpiece (29) arranged in reciprocatable manner between the suction disks (19, 20) in the plane of the movement path of cigarette group (10), said mouthpiece (29) finishing flush or slightly projecting beyond the front side of cigarette group (10) in the conveying direction and as a result of mouthpiece (29) blank (14) can be raised or detached from the suction disks (19, 20) at least during the initial phase of the wrapping process.

2. Apparatus according to claim 1, characterized in that the front of the mouthpiece (29) receiving blank (14) has sharpened leading edges (40).

3. Apparatus according to claims 1 or 2, characterized in that by means of a separate conveyor, particularly a chain conveyor (12) the cigarette groups (10) can be moved relative to the mouthpiece (29) and through the latter.

4. Apparatus according to one of the claims 1 to 3, characterized in that mouthpiece (29) is constructed as a cross-sectionally closed wrapping for the cigarette group (10), preferably with a slit (35) in base wall (31) for the passage of the drivers (13) of chain conveyor (12) and with thin side walls (32, 33) compared with the top wall (30) and base wall (31).

5. Apparatus according to one of the claims 1 to 4, characterized in that the cigarette group (10) can be moved out of mouthpiece (29) before the blank (14) is completely removed from suction disks (19, 20).

6. Apparatus according to one of the claims 1 to 5, characterized in that the cigarette group (10) can be inserted with blank (14) into a packing web (24) with upper wall (25) and lower wall (26), the distance from entrance end of packing web (24) to suction disks (19, 20) being such that cigarette group (10) with blank (14) enters packing web (24) before blank (14) has been completely removed from suction disks (19, 20).

7. Apparatus according to one of the claims 1 to 6, characterized in that the blank (14) separated from a packing material web (24) is temporarily held on suction disks (19, 20) by at least three groups of suction bores (22, 23a, 23b) distributed over the length of the periphery of suction disks (19, 20) whereby one group of suction bores (22) engages a front area of blank (14) in the conveying direction thereof and in each case one further group of suction bores (23a, 23b) is in a relative position above and below mouthpiece (29) during the displacement of blank (14) by mouthpiece (29) or cigarette group (10).

8. Apparatus according to claim 7, characterized in that the group of suction. bores (22) can be vented for engaging the front area of blank (14) before the latter has reached the end position relative to cigarette group (10).

9. Apparatus according to claim 8, characterized in that the suction bores (23a, 23b) located above and below mouthpiece (29) when the latter accepts blank (14) are jointly ventable, particularly by a connecting duct (45) connectable to a joint venting bore (44), as soon as blank (14) has been accepted by mouthpiece (29) or cigarette group (10).

10. Apparatus according to one of the claims 1 to 9, characterized in that a cutter roller (18) provided with suction bores (62, 63) and equipped with preferably two cutting knives (57, 58) is positioned in front of the suction disks (19, 20), one cutting knife (57) thereof cooperating with a fixed counterknife (59) for a separating cut and the other cutting knife (58) thereof cooperating with a counterknife (counter-roller 60) having a varying distance from the periphery of cutter roller (18), particularly for a perforation cut.

11. Apparatus according to claim 10, characterized in that the movable counterknife (counter-roller 60) comprises a rotating counter-roller (60) which, when performing a perforation cut, cooperates with the particular cutting knife (58) of cutter roller (18) by engaging thereon.

12. Apparatus according to claim 11, characterized in that the cutter-roller (60) is positioned on a rotating supporting roller (61), whose shell is spaced from the shell of cutter roller (18), counter-roller (60) being mounted in such a way that it projects radially beyond the shell surface of supporting roller (61).

13. Apparatus according to claim 10, characterized in that the cutter roller (18) is provided with at least two groups of separately controllable suction bores (62, 63).

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