1. Technical Field
The invention relates to a method of filling and closing bags made of sheet material, in particular for (cut) tobacco, having a pocket which has a closable opening and is intended for accommodating the bag contents, wherein the bag is filled in an upright position on a circulating carrier or turret and is then closed by means of closure strips in the region of the opening. The invention also relates to an apparatus for implementing the method.
2. Prior Art
In the case of a known apparatus for filling and closing tobacco bags (EP 0 870 683 B1), bags are positioned in pairs on the circumference of a turret which rotates about a vertical axis and forms a carrier for the bags. The turret forms—as in the case of a square—four retaining surfaces, located opposite one another in pairs in each case, for in each case two tobacco bags. The pockets are sealed closed in the region of the opening once a tobacco portion has been introduced.
An apparatus according to this prior art lacks output capacity. Furthermore, it is technically unavoidable that the overall length of the apparatus is relatively large.
Accordingly, it is the object of the invention to propose measures for high-capacity production of bags, in particular tobacco bags, while the finished bags have a quality which meets the market requirements.
In order to achieve this object, the method according to the invention is a method of filling and closing bags made of sheet material or the like, in particular for (cut) tobacco, having a pocket which has a closable opening and is intended for accommodating the bag contents, wherein the bag is filled in an upright position on a circulating carrier or turret and is then closed by means of closure strips in the region of the opening, characterized by the following features: a) the prefabricated, empty bags are transported along a feed path, or by a feed conveyor, into the region of a filling and closure station, b) the bags are received by a filling and closure conveyor, in particular by a turret, and conveyed by the latter, in a plane transverse to the feed path, in particular in an upright plane, through filling, closure and possibly other processing stations, and c) the filled and closed bags are transferred from the filling and closure conveyor to a removal conveyor, which transports the bags away, in particular in a direction parallel to the feed conveyor.
A special feature of the present method may be considered that of the handling of the bags, namely in particular filling, closing and possibly wrapping, taking place in a movement plane of the bags which runs transversely to the feed and/or removal direction. Accordingly, the movement path of the bags during processing is directed along a circulatory path with a horizontal axis of rotation or circulation. This gives rise, in the first instance, to the movement paths being divided up in a space-saving manner. Furthermore, it is possible for a plurality of bags to be processed in parallel (transversely directed) planes preferably simultaneously and synchronously without this giving rise to a significant increase in the overall length of the apparatus.
As far as the apparatus is concerned, a rotary bag conveyor or turret with a horizontal axis-of-rotation element forms the core of the invention. The bag conveyor, which possibly comprises a plurality of sub-turrets arranged equiaxially one beside the other, transports the bags through a plurality of processing stations, preferably with cyclic driving. The turret, or each sub-turret, has a polygonal, in particular hexagonal, cross section, that is to say it has six planar outer surfaces or wall portions, on each of which a securing means for a bag is fitted. Arranging the turret, or the sub-turrets, in upright planes or transversely to the feed direction of the bags makes it possible, without any significant change in the machine dimensioning, for a plurality of sub-turrets to be located one beside the other in the axial direction and thus to increase the output capacity of the apparatus to a considerable extent.
The bags positioned on the turret, or on the turret surfaces, run through processing stations appropriate to the operating sequence, namely a filling station 41, optionally suction-extraction station, a closure or sealing station and a wrapping and discharging station. Predominantly fixed-location, movable processing mechanisms are arranged in the region of these stations.
Further details of the invention relate to the specially designed processing mechanisms of the bag in the different stations. These details will be explained more specifically hereinbelow with reference to the exemplary embodiments of the invention which are illustrated in the drawings, in which:
The exemplary embodiments in the drawings concern the production and/or filling and the closure of bags 10 for a respective tobacco portion 11 or for other pack contents in piece, granular or fibrous form. The bag 10 consists of a possibly multi-layered sheet material or of other, thin packing material.
The bag 10 is formed from a single, strip-form blank. Two portions of the blank, which are folded over along a folding edge and connected to one another at their peripheries by seams 13, form a front wall 14 and rear wall 15 of a pocket 12. The rear wall 15 forms a continuation projecting beyond the pocket 12, namely a wrapping flap 16. The pocket 12 has an opening 17 which serves for filling the bag 10 and for removing the contents. The opening 17 can be closed in a suitable manner, in particular by a reusable closure strip 18, which is preferably designed as a peel/seal seam.
For filling and closing the bag 10, the latter is fed in a prefabricated, unclosed state to a filling and closure station. In the region of the latter, the opening 17 is freed, the tobacco portion 11 is introduced and the pocket 12 is then closed. This is followed by a folding or wrapping process, provided the bag 10, as is the case here, is designed with a wrapping flap 16. The dimensions of the bag 10 are preferably selected so as to give rise to three folding or wrapping portions, these being indicated in
During completion of the bag 10, namely during folding, the procedure is such that the central portion 19 is gripped by folding or retaining mechanisms, in the present case by retaining fingers 21, 22, which grip and fix the central portion 19. Thereafter, in the first instance, the pocket 12 is folded, as a folding leg, against the central portion 19. Finally, the peripheral flap 20 is folded over against the pocket 12, in this case against the rear wall 15 of the same. In this finished position, the wrapping flap 16 or the peripheral flap 20 thereof is fixed by a standard retaining means, in this case by an adhesive-bonding strip or a tape 23. In the case of the present exemplary embodiment, this is fitted on the completed, wrapped bag 10 (
The bag 10 is retained in a vertical plane prior to, and during, the wrapping process. It is a special feature here that the pocket 12 is located above the wrapping flap 16 and, accordingly, is placed against the central portion 19 by being moved or folded downward (
The central subassembly of the filling and closing station is a bag conveyor, which conveys the bags 10 through the necessary number of processing stations. The bag conveyor is a (drum) turret 24, a hollow body which is driven in rotation about a horizontal axis, to be precise in successive sub-steps from station to station. The turret 24 has a continuous outer wall 25, forming a carrier of the bags 10, which abut on the outside. In the exemplary embodiment according to
Mounts 28 for bags 10 are arranged on the outside of the turret 24, namely on the outer wall 25 thereof. For this purpose, the turret 24 is provided with a polygonal outer contour. A plurality of respectively planar wall portions 29 are connected to one another to form a uniform cross section. A particularly advantageous embodiment is that which is shown in
The turret 24 is mounted such that it can be rotated about a horizontal axis. This gives rise to a closed circulatory path for the mounts 28 in a vertical plane. The turret 24 preferably comprises a plurality of sub-turrets 30, 31, 32, 33 which are located one beside the other in the axial direction. In the case of the present exemplary embodiment, the turret 24 with four sub-turrets 30, 31, 32, 33 forms a unit, namely a common hollow body. The latter is mounted on a common driveshaft 27. The sub-turrets 30, 31, 32, 33 are designed to correspond to one another and have the same dimensions. The standard configuration means that the bags 10 arranged on each sub-turret 30, 31, 32, 33 are conveyed simultaneously through the processing stations assigned to each sub-turret 30, 31, 3233, and are processed simultaneously therein. Accordingly, this gives rise in each case to the simultaneous completion and depositing of a number of bags 10 which corresponds to the number of sub-turrets 30, 31, 32, 33. As an alternative, it is possible for the sub-turrets 30, 31, 3233 to be designed as independent bag conveyors which either are mounted on a common driveshaft or can be driven separately. In the case of this embodiment, the sub-turrets 30, 31, 32, 33 can be exchanged individually. Overall, the capacity of the turret 24 can easily be increased by a change in the number of sub-turrets 30, 31, 3233, without this necessitating any significant change in the machine-specific dimensioning of the apparatus.
The turret 24, or each sub-turret 30, 31, 3233, is provided with a plurality of mounts 28 which are distributed along the circumference. An advantageous design is one in which a mount 28 is fitted on each wall portion 29. The mounts 28 are plate-like moldings with mechanisms or auxiliary means for retaining and aligning a respective bag 10. The retaining means may act mechanically and/or pneumatically.
In the case of the exemplary embodiment shown, the mount 28 is fitted eccentrically on the respective wall portion 29, that is to say it is offset in the direction of rotation of the turret 24. The plate-like mount 28 forms a planar abutment surface 35 essentially for the abutment of the planar, aligned wrapping flap 16. A trough-like shaped surface 36 is also formed for the abutment of the pocket 12.
The prefabricated, unfilled bag 10 is placed on the mount 28 and fixed by suction air and/or by clamping mechanisms. A pocket holder 37, which is connected in a pivotable manner to a free end of the plate of the mount 28, is placed on the bag 10 such that essentially the region of the pocket 12 is gripped and fixed. A further retaining mechanism grips the wrapping flap 16, namely a clamping lever 38, which is of angular design and is mounted in a pivotable manner on a carrying part 39 of the adjacent wall portion. The clamping lever 38 grips the wrapping flap 16, by way of an angular retaining leg, in the region of the peripheral flap 20. As an alternative, the clamping lever 38 can perform some other, or additional, task. If—as an alternative to the exemplary embodiments shown—the tape 23 is fed to the filling and closing arrangement together with the unfilled bag 10, the clamping lever 38 can serve as a covering mechanism for the exposed region of the adhesive-bonding side of the tape 23. The leg of the clamping lever 38 covers over the adhesive-bonding part of the tape 23, preferably at a small distance from the adhesive-bonding surface.
An important retaining means for the bag 10 in the region of the mount 28 is constituted by suction bores 34 both in the region of the abutment surface 35 for the wrapping flap 16 and in the region of the shaped surface 36 for the pocket 12. It is also the case when the wrapping flap 16 is straightened out that the bag 10 is fixed largely over the entire surface area by the suction bores 34. The latter can be switched off during the wrapping operation.
The relative positions of the turret 24 and/or the rotary steps are selected such that, during the respective standstill, two mutually opposite wall portions 29 are directed vertically and in each case two further wall portions 29 in the bottom region and in the top region are directed obliquely in the form of a roof, in a position in which they are symmetrical to an imaginary vertical center plane. The stations of the turret 24 are distributed such that, in a charging station 40 at the bottom, the bags 10 or corresponding blanks are placed on the obliquely downwardly directed mount 28. The bag 10 is fixed by virtue of the pocket holder 37 and the clamping lever 38 being pivoted until they butt against the bag 10 and by virtue of negative pressure at the suction bores 34.
The next conveying cycle brings the bag 10 to an idling station, in which there are no operating steps carried out. Thereafter, the mount 28, together with the bag 10, passes into a filling station 41. The pocket 12 is then located in the bottom part of the mount 28, with the opening 17 oriented upward. The tobacco portion 11 is then introduced into the (upright) bag 10 from above, by suitable filling mechanisms, via the freed opening 17.
In the next station, in which the bag 10 is in an oblique position, in the case of the present exemplary embodiment (tobacco) particles are removed from the region of the opening 17 in an appropriately equipped suction-extraction station 69.
Following a further switching step, the mount 28 passes into a position in which the bag 10 assumes a downwardly inclined oblique position. In this station, a closing station 42, the opening 17 is closed, to be precise by virtue of a closure seam being applied by thermal sealing. An advantageous alternative provides for the closing station 42 to be shifted into the region of the suction-extraction station 69 and for the latter to be dispensed with out replacement. In this variant, the bag 10 is located in an upwardly inclined oblique position, and therefore it is not possible for any contents to escape from the (still open) pocket 12.
Thereafter, corresponding rotation of the turret 24 conveys the mount 28 into an upright position again. In this region, a wrapping station 43, at least the wrapping flap 16 is moved into the correct position. In the present case, furthermore, the tape 23 is applied and, in the region of this station 43, the finished bag 10 is transferred to a removal conveyor 44.
The operating stations of the turret 24 are fitted with task-appropriate fixed-location subassemblies. In a suction-extraction station 69, a suction-extraction subassembly 45 enters, by way of a tapering suction connector 46, into the opening 17 of the pocket 12 and takes effect above the filling region for the suction extraction of particles. The opening 17 here is retained in the closed position, by way of the curved pocket holder 37, to the extent where the suction extraction of tobacco from the interior of the pocket 12 is avoided. The particles extracted by suction in the closing region of the opening 17 pass into a collecting space 47 and are led away through a transversely directed, axis-parallel suction tube 48. In the case of a plurality of sub-turrets 30, 31, 3233 arranged one beside the other, a common suction tube 48 is provided for a plurality of adjacent collecting spaces 47 and suction connectors 46.
As can be seen from
Furthermore, the closing station 42 is designed in a particular manner. A free peripheral region of the front wall 14 of the pocket 12 is connected to the rear wall 15 here by thermal sealing, or at any rate by the transmission of heat and pressure. A sealing mechanism 49 is provided for this purpose, and this sealing mechanism, while the turret 24 is at a standstill, is pressed onto the bag 10 in the region of the opening 17. A heated sealing bar 50, which in the present case is wedge-shaped, is pressed, by way of a comparatively narrow sealing edge, against the sheets which are to be connected, and this therefore produces a sealing seam, in particular a peel/seal seam. The sealing mechanism 49 can be moved transversely, namely raised and lowered, in relation to the bag 10, in the present case by virtue of being arranged on a pivoting lever 51. When the sealing bar 50 is lifted off from the sheets, a holding-down means 52 takes effect, that is to say a crosspiece-like retaining mechanism which butts against the sheets in a free region, which is offset in relation to the sealing seam. This retaining mechanism is mounted on the sealing mechanism 49 parallel to the sealing bar 50, to be precise in a depression 53 of a holder, and it is subjected to the loading of a spring 54. When the sealing bar 50 is lifted off, the holding-down means 52, in the first instance, remains in abutment against the sealed sheets and thus prevents the same from lifting off with the sealing bar 50. As the lifting-off movement continues, the holding-down means 52 also comes away from the bag 10. An insulating delimiting means, namely a strip 55 made of rubber or plastics material, in particular TEFLON®, is applied between the sealing bar 50 and holding-down means 52. The strip 55 is applied to the holding-down means 52, namely to the bottom peripheral region thereof, and is lifted off, and moved into position, therewith. If the suction-extraction station 69 is dispensed with, the closing station 42 may be arranged in the region of the same, that is to say on a wall portion 29 which is directed upward, as seen in the direction of rotation.
In the case of the present exemplary embodiment, the wrapping station 43 is configured as a multifunctional station. The bags 10 are positioned such that the pocket 12 is positioned in the top region and the wrapping flap 16 extends beneath the pocket 12.
In the station 43, a first folding or wrapping step is carried out on the bag 10. The fixing of the top bag part, namely of the pocket 12, is released. For this purpose, the pocket holder 37 is pivoted away. Furthermore, the air supply to the suction bores 34 in the region of the shaped surface 36 is stopped. It is thus possible for the pocket 12, in a first wrapping step, to be pivoted downward into the position according to
The downwardly oriented region of the wrapping flap 16, namely the peripheral flap 20, is then gripped and folded, by upward movements, against the outwardly directed free side of the bag 10 or of the pocket 12 (
The holder 57 for the pivot lever 56, on the one hand, and the flap folder 59, on the other hand, is arranged at a fixed location within the turret 24 (which is open at one end). The mechanisms 56, 59 pass through specifically positioned apertures or openings in the outer wall 25 of the turret 24 and through corresponding openings and apertures in the region of the mount 28. It is also possible for other processing mechanisms to be arranged, if necessary, at a fixed location within the turret 24.
Prior to the flap folder 59 taking effect, the retaining means for the wrapping flap 16, namely the clamping lever 38 and suction bores 34 in the region of the abutment surface 35, are released. The holder 57 with the folding mechanisms for the bag 10 in the station 43 is illustrated in FIG. 10—without any further details. The holder 57, which is illustrated in a simplified state, is designed as a hollow body for accommodating gear-mechanism parts and drive means for the folding or wrapping mechanisms, namely for the fingers 58, on the one hand, and the flap folders 59, on the other hand, wherein a plurality of sub-turrets 30, 31, 3233, which are connected to form a unit, have a common holder 57 for the folding or wrapping mechanisms and this holder 57 runs in an axis-parallel manner within the turret 24. Furthermore, the wall portions 29 and the mount 28 are provided with slot-like apertures which allow the folding and retaining mechanisms to pass through in the region of this station.
The auxiliary mechanisms described in conjunction with
A further step is carried out in the station 43. The tape 23 for fixing the peripheral flap 20 on the pocket 12 is moved into position. The tapes 23 are fed by a tape conveyor 64 and held in readiness for transfer to a bag 10. For this purpose, a transfer mechanism is provided for a respective tape 23. This mechanism comprises a pivot arm 65 with a tape holder 66 which is fitted in a pivotable manner on the pivot arm and, in this case, is designed as a suction mechanism, that is to say as an elastic, cap-like element which is applied to the free side of a tape 23 in the region of the tape conveyor 64 and grips the tape 23, and removes it from the tape conveyor 64, by negative pressure. Movement of the pivot arm 65, on the one hand, and of the tape holder 66, on the other hand, causes the latter to pass into a position in which the tape 23 can be positioned appropriately on the bag 10 (transfer position according to
The bag 10 is thus complete. In the region of the station 43, the bag 10 is discharged and transported away, to be precise by the removal conveyor 44, which is designed as an endless or belt conveyor. The bag 10 is lifted off from the mount 28, and deposited on the removal conveyor 44, with the aid of a transfer conveyor. This task is performed here by the retaining fingers 21, 22 in conjunction with the carrying lugs 61, 62. The latter can be moved in an axis-transverse manner, by means of pivot levers 67, out of the position in the turret 24 and can be deposited on a top strand of the removal conveyor 44. The retaining mechanisms, namely carrying lugs 61, 62 with the retaining fingers 21, 22, here can be rotated relative to the pivot lever 67, and therefore the carrying lugs 61, 62 are directed downwards when the bag 10 is deposited on the removal conveyor 44. In order for the bag to be transferred or to be released from the retaining fingers 21, 22, the latter can be moved apart from one another, to be precise by virtue of the carrying lugs 61, 62 being moved apart from one another, and therefore the retaining fingers 21, 22 are freed from the position between the wrapping flap 16 and pocket 12.
The carrying lugs 61, 62 are mounted in a rotatable and axially displaceable manner on the axis-parallel axial carrying element 63. As is shown in
The pivot arms 65 for the tape holder 66, these pivot arms being assigned to each station, are also mounted in a pivotable manner on the continuous axial carrying element 63.
The design and relative positioning of the turret 24 and the resulting conveying direction of the bags 10 allow a particular material flow for the apparatus as a whole (
The turret 24 may also advantageously be designed in the manner shown in
It is also the case here that actuating mechanisms are fitted in the interior of the turret 24. The carrier or holder 57 for the mechanisms 56 and 59 is mounted in the interior of the turret 24 with the axis-of-rotation element 72 in a relative position corresponding to the relevant operating station. The mechanisms are passed through the apertures 70 and/or openings 71. The mechanisms 56, 59 are driven via driveshafts 78 which are mounted at a fixed location and enter into the turret 24 in the region of the drive side of the latter, to be precise through the covering plate 77.
On the opposite side, namely in the region where the turret 24 is supported on the axis-of-rotation element 72, the turret 24 is provided with an end wall 79. The latter is supported on the axis-of-rotation element by way of the rotary bearing 73. The end wall 79 is provided with a system of pneumatic lines, namely with suction bores 80. These are connected via further suction lines or channels to the wall of the turret 24, and/or to the mounts 28 for the bags 10, for supplying the suction bores 34. The suction bores 80 of the end wall 79 are connected via a fixed, annular vacuum disk 81, by way of conventional connection channels and connection lines 82, to a negative-pressure source.
Number | Date | Country | Kind |
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10 2007 053 854.7 | Nov 2007 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2008/009245 | 11/3/2008 | WO | 00 | 4/27/2010 |