Filling device and method for filling bags with a respective unsealed upper end

Abstract

The invention relates to a filling device for filling bags with a respective unsealed upper end and at least two layers lying on top of one another. A filling station for filling the bags in characterised in that the filling device comprises at least one layer movement device (30) for moving the at least one layer of the bag relative to the at least one second layer, with which the layers of the bag can be acted upon, wherein the layer movement device is arranged in front of the filling station.

Claims

1. A filling device for filling bags with a respective unsealed upper end and at least two layers lying on top of one another, the filling device comprising: a filling station for filling the bags, wherein the filling station comprises suction cups for opening the bag, at least one layer-moving device for moving said at least one layer of the bag in relation to said at least one second layer, with which it is possible to have an impact upon the layers of the bag, wherein the layer-moving device is arranged in front of the filling station, wherein the layer-moving device comprises at least one suction device, which engages with the outside of a layer of the bag, a transport device configured to transport the bag from the layer-moving device to the filling station such that the layers of the bag lie on top of one another, the interior of the bag is free of tools while the bag is being transported, and no fluid or ambient air gets into the interior of the bag, and at least one retaining device with which the bag can be held in the at least one layer-moving device, wherein the retaining device holds the layers of the bag in such a way that they are compressed.

2. The filling device in accordance with claim 1, wherein at least one means of support, to hold a bag in the layer-moving device, is provided for, which remains stationary within the filling device prior to and during the time that the layer-moving device is having an impact, or can be moved within the filling device with a stroke of a maximum of 15 mm.

3. The filling device in accordance with claim 2, wherein the at least one means of support can be moved within the filling device with a stroke of a maximum of 10 mm.

4. The filling device in accordance with claim 1, wherein the layer-moving device comprises at least one fluid nozzle, with which a jet of a fluid can be directed at the top of the bag.

5. The filling device in accordance with claim 4, wherein the fluid is a gas which is subject to excess pressure.

6. The filling device in accordance with claim 5, wherein the gas is air.

7. The filling device in accordance with claim 4, wherein the fluid nozzle is designed in such a way that the jet of fluid is oriented towards a longitudinal axis of the bag.

8. The filling device in accordance with claim 4, wherein at least one electrode is provided for, with which the jet of fluid can be energized with an electric current.

9. The filling device in accordance with claim 8, wherein the electrode is subordinated to the outlet of the fluid nozzle.

10. The filling device in accordance with claim 4, wherein at least one valve is provided for, with which the jet of fluid can be conducted through a source of excess pressure and/or may be interrupted in order to be able to generate a fluid thrust.

11. The filling device in accordance with claim 1, wherein the suction device touches the upper end of the bag or overlaps the upper edge of the bag.

12. The filling device in accordance with claim 1, wherein the layer-moving device comprises at least two suction devices, and at least one suction device in the at least two suction devices is provided for on each side of the bag, wherein the at least two suction devices are offset from one another on the plane of the bag.

13. The filling device in accordance with claim 1, wherein the suction device is a bellows suction cup.

14. The filling device in accordance with claim 1, wherein the suction device is placed on at least one supporting element, in regard to which the supporting element remains fixed within the filling unit while the layer-moving device is in operation.

15. The filling device in accordance with claim 1, wherein the at least one retaining device is configured to grip the bag underneath a suction cup.

16. The filling device in accordance with claim 1, wherein the at least one retaining device is designed in the shape of a bar and includes a gap in the area of a suction cup device and/or at least one recess.

17. A form fill seal device comprising a bag-forming device, with which successive tubular sections made of a tube material, the lower ends of which can each be equipped with a base, can be separated, to form bags that are open at the top; a filling device for successively filing a product into the bags; a head or base seam welding station, with which upper openings of the bag can be closed; retaining devices, with which the bags can be held within at least one of the bag- forming device, the filling device, or the head or base seam welding station; conveyors, with which the bags can be individually placed between the bag-forming device, the filling device, or the head or base seam welding station, wherein the filling device is designed in accordance with claim 1.

18. A method for filling bags with one respective unsealed upper end and at least two superimposed layers, wherein the filling is done at a filling station comprising suction cups for opening the bag, the method comprising: exerting an impact upon at least one layer of the bag, using at least one layer-moving device, in order to move said layer in relation to said at least one second layer, wherein the layer-moving device is placed in front of the filling station and the layer-moving device comprises at least one suction device, which engages with the outside of a layer of the bag; transporting the bag from the layer-moving device to the filling station such that the interior of the bag is free of tools while the bag is being transported and no fluid or ambient air gets into the interior of the bag; and holding the layers of the bag in such a way that they are compressed.

Description

(1) Further benefits, features and details of the invention are apparent from the description below, where various embodiments are explained in detail, making reference to the figures. In that respect, the features mentioned in the claims and description can always be individual, self-contained features essential to the invention or any combinations of features mentioned. In the context of the entire disclosure, features and details which are described in connection with the method in accordance with the invention apply, naturally also in connection with the filling device and/or form fill seal device in accordance with the invention, and vice versa, so that, mutual reference is, or can always be, made to the individual aspects of the invention, in regard to the disclosure. The individual figures show:

(2) FIG. 1 Lateral view of an FFS machine, which comprises the filling unit in accordance with the invention.

(3) FIG. 2 Detailed perspective of a filling unit in accordance with the invention

(4) FIG. 3 The III-III view of FIG. 2

(5) FIG. 4 The IV-IV view of FIG. 3

(6) FIG. 1 shows a form fill seal machine 1, often abbreviated to “FFS machine”, which is suitable for forming, filling and closing bags, and in which the filling unit in accordance with the invention can preferably be provided for. Said device 1 comprises a supporting arm 2, on which a winding 3 with a tubular film 4 rests. The tubular film 4 preferably has side gussets not shown in FIG. 1. The feed rolls that can also sometimes be driven, ensure a generally continual winding up of the tubular film 4. The lever 9, subjected to a load through a piston/cylinder unit 10, which supports a deflection roller 6 and is, as a whole, frequently designated a compensating device, and the feed rolls 7 and 8, as well as the pair of feed rollers, ensure, overall, in a known way, that the tubular film 4 continues to be moved intermittently on its further transport route. The feed roll 8a is a component of a register device 29, with which the length of the transport route of the tubular film 4 can be adjusted to the format of the subsequent bags 27. For that purpose, the feed roll 8a is placed disposably in relation to the device 1. A manual spindle drive, or one operated by an electric motor, that is inherently known, is available to effect the displacement.

(7) Using the pair of feed rollers 15, the tubular film 4 is pushed through the sealing jaws 33 of a transverse welding station 13, and through a transverse cutting station 16. The tools of the transverse welding station 13 and the transverse cutting station 16 can be pushed towards the the tubular film 4 in a way not described further, for instance through a parallelogram arrangement 14, on planes orthogonal to the feed direction of the tubular film 4, and be moved away from the latter. Once the grippers 17 have gripped the tubular film 4, a tubular section 18 within the transverse cutting station 16 is separated from the tubular film 4 above the grippers 17. A transverse weld, which constitutes the base of the tubular section 18 to be formed in the next work cycle of the device 1 is simultaneously applied to the tubular film 4 in the transverse welding station 13, above the cutting edge. Base seams are accordingly generated in the transverse welding station 13. In general, the head or base seams cannot only, even if preferably, be created by way of a transverse weld, but other joining methods, such as gluing, are also conceivable.

(8) The grippers 17 convey the tubular section 18 to a transfer point, where further grippers 19 pick up the tubular section 18 and transport it to a filling station 20.

(9) Said transfer point is the layer-moving device 30 of the filling unit in accordance with the invention. Said layer-moving device 30 may, optionally, interact with a base-cooling device 31. Further details, the construction and the function of the layer-moving device are shown further down in connection with further figures.

(10) At the filling station, the tubular section 18 is handed over to stationary grippers 21, and opened by the suction cups 22, so that the product, which is guided by the filling device 23, can enter the tubular section 18. In that respect, the tubular section 18 has its lower end lying on a conveyor belt 24, so that the tubular section 18 is not excessively burdened along its longitudinal edges during the filling process. Further grippers 25 convey the filled tubular section to the head or base seam welding station 26, where the tubular section 18 is sealed with a head or base welding seam, thus forming a finished bag 27. The tubular section 18 can be closed, in its head section, using another joining method. The finished bag 27 is conducted, by the conveyor belt 24, out of the device 1. In this respect, the bag 27 is usually very much higher (in the “y” direction) than it is wide (in the “x” direction).

(11) FIG. 2 now shows some important features of the filling unit in accordance with the invention in detail. A finished bag can be seen on the far right, which has, for example, been produced using the transverse cutting station 16 and transverse welding station 13. Said bag 18 can be made available to the filling unit 40 by means of the grippers 17. In that context, the bag 18 first of all reaches the layer-moving device 30. A retaining device 41 is provided for here, with which the bag 18 can be—or is—held. In the embodiment shown, the retaining device 41 is embodied by two holding bars 42, of which each one is abuts an external wall of the bag. A lever mechanism connected to the machine frame can be provided for, for this purpose, so that an opening and closing movement is enabled. Once the bag 18 is held by the retaining device 41, the grippers 17 can be released from the bag and swing back, in order to pick up the next bag 18.

(12) Preferably at least one fluid nozzle 43 is arranged in the layer-moving device 30, which is preferably fastened to a stationary bar 44. With this fluid nozzle 43, which can be subjected to a fluid that is subject to excess pressure via a fluid duct 45, a fluid is added in the direction of the arrow 46. The fluid, preferably air, directly reaches the upper edge 47 of the bag 18, so that the two layers of the bag can be separated from one another. Consequently, one layer of the bag is moved in relation to a second layer. The bag 18 is, in particular, at least partially open, which is actually shown in FIG. 2. In order to continue to produce the relative movement of the layers of the bag 18, as an alternative, or in addition to the fluid nozzle, suction cups 48 are provided for, which are arranged above the retaining device, i.e. running counter to the direction z, and can likewise be made to abut a respective external wall of the bag from the outside. Each suction cup 48, is, for that purpose, arranged on a support 49, wherein the support can be arranged in such a way that it is stationary or can be movable in relation to the machine frame, for instance via a lever mechanism, which is, however, not shown. The suction cups 48 can, alternatively, be arranged on holding jaws 42 of the retaining device 41, so that the suction cups already abut the outside of the bag, if the holding jaws have been closed. Since it can be provided for that the suction cups 48 only perform a small stroke movement, the latter can be designed as bellows suction cups or as wave bellows suction cups, as is also shown in FIG. 2. The functioning is as follows: Once the suction cup 48 abuts the external wall of the bag 18, it is subjected to negative pressure via the vacuum duct 50. Once the external layer has been made to abut the suction cup 48, so that no air is sucked through between these two elements, the negative pressure which continues to exist causes the suction cup to retract, so that the external wall or the layer concerned is moved. It is important for the supports to remain in a fixed position during this procedure, i.e. not undertake any movement in order to open the bag. Since this procedure is done with both layers of the bag, the two layers are, in this way, separated from one another. Should fluid meanwhile continue to enter through the fluid nozzle 43, a relative movement of the layers of the bag occurs not only in the area of the suction cups, but also in the area between the suction cups 48 and the retaining device 41.

(13) It is, moreover, as shown in FIG. 2, advantageous to provide for a device 51 for ionizing the jet of fluid. Two electrodes are provided for, for this purpose, which are arranged on both sides of the jet of fluid, and between which an electric current is applied. In this way, the jet of fluid can be ionized, so that it can reduce electrical charges on the layers of the bag. That leads to the layers being better able to be separated. The electrodes can be arranged in a stationary manner, are, however, preferably directly connected to the fluid nozzle 43.

(14) Once the bag 18 has been opened in the layer-moving device 30, the jet of fluid can be interrupted. A valve 52, with which the jet of fluid can be interrupted, is provided for in the fluid duct 45, for this purpose. The negative pressure, which acts upon the suction cups 49, is interrupted or reduced as well. Once the grippers 19 have gripped the bag 18, the retaining device 41 can be removed from the bag 18. The bag 18 can now be transported to the filling station 20 by the grippers 19, so that conventional suction cups 22, which are arranged on supports 61 that can be moved by means of levers 60, can open the bag 18. Since the layers of the bag 18 in the layer-moving device have already, in sections, been separated from one another or have been moved in relation to one another, the bag is opened, for the purpose of being filled, substantially more reliably. It can, on the other hand, be observed in the prior art that the suction cups 22 lose contact with the bag during the opening procedure, or the two layers cannot be separated from one another, so that the bag ends up not being opened.

(15) Once the bag 18 has been opened, it—and/or the hopper 62 of the filling device 23 can be moved, so that the hopper 62 extends into the interior of the bag 63. The bag can subsequently be filled.

(16) FIG. 3 now shows the III-III view of FIG. 2. Two fluid nozzles 43 can be seen in this figure, which are both arranged on the bar 44, wherein they assume an angle in relation to the direction z. The position of the fluid nozzles can be symbolized by the arrows S. This direction can also be termed the main direction of flow, in regard to which it is, however, stipulated that the jet of fluid is diversified by means of the fluid nozzles, which is in each case shown by multiple arrows 46. The two fluid nozzles are displaced outwardly in relation to the imaginary center line of the bag 18, i.e. in the direction of the vertical bag edges. It is thereby possible to increase the area of influence of the jet of fluid, and even increase it with the area of the center line 64. For the sake of improved clarity, the devices 51 for ionizing the jet of fluid are not shown in FIG. 3. It is, however, to be emphasized that at least one such device 51 is allocated to each fluid nozzle 43.

(17) What is shown, on the other hand, is the holding bars 42 of the retaining device 41. It is, for example, shown that the holding bars 42 do not need to be integral, but may be disconnected, in order to enable the bag material in the central area to engage in an opening movement. In an enhancement, it can, in addition, be provided for that the holding bars are movable in or against the direction y, so that even more scope for movement can be accorded to the material of the bag.

(18) The suction cups 48, of which only one is visible, can also be displaced in relation to the center line 64, which will be explained in more detail based on FIG. 4. In addition, it can be discerned that the suction cups 48 are positioned near the upper edge of the bag 66, or touch it. Overlapping is also possible. That means that the suction cup can partially extend beyond the upper edge of the bag.

(19) FIG. 4 shows the IV-IV view of FIG. 3. A further embodiment can be seen in this view, in which the bag comprises 18 side gussets 65. It can, furthermore, once again be seen that the suction cups 48 can be displaced in the direction of the lateral edges in relation to the center line. This serves the purpose of the suction cups not sucking mutually, for, in this case, the bag could not be opened.

(20) It can, moreover, be seen in FIG. 4 that the fluid nozzles 43 can be twisted around their own longitudinal axis in relation to the plane in the direction R defined by the bag 18. It is thereby achieved that the jet of fluid in any case reaches the edge of the bag 66, even if the fluid nozzle 43 does not point precisely to the plane defined by the bag 18.

(21) Finally, another variant embodiment is shown, based on FIG. 4, where the holding bars 42 are not interrupted, as explained based on FIG. 3, but only have recesses 67, which likewise allow the material of the bag to move. In this representation, the holding bars 42 are shown in the open position, which, however, does not need to be the case. This only serves the purpose of improved clarity here.

(22) Finally, it is to be emphasized that the directions, as well as directional relationships, specified, such as “at the top” or “above”, are always to be understood as the regular directions in relation to gravity.

(23) TABLE-US-00001 List of reference signs 1 Form fill seal machine, FFS machine 2 Supporting arm 3 Winding 4 Film 5 Feed roll 6 Deflection roller 7 Feed roll 8 8a Feed roll 9 Lever 10 Piston/cylinder unit 11 12 13 Transverse welding station 14 Parallelogram arrangement 15 Pair of feed rollers 16 Transverse cutting station 17 Gripper or grippers 18 Tube section 19 Gripper or grippers 20 Filling station 21 Stationary gripper 22 Suction cup or cups 23 Filling device 24 25 26 27 Bag 28 29 30 Layer-moving device 31 32 33 Sealing jaw 34 35 36 37 38 39 40 41 Retaining device 42 Holding bars 43 Fluid nozzle 44 Bar 45 Fluid duct 46 Diversification of the jet of fluid by means of fluid nozzles 47 48 Suction cup or cups 49 Suction cup or cups 50 51 Device for ionizing the jet of fluid 52 Valve 53 54 55 56 57 58 59 60 Lever 61 Support(s) 62 Hopper 63 Interior of the bag 64 Imaginary center line 65 Side gussets 66 Upper edge of the bag 67 Recess R Indicates the direction y Indicates the direction S Symbolizes the position of the fluid nozzles