Filling device and method for filling upwardly open packaging containers, and form-fill-seal device

Abstract

The invention describes a filling device with a discharge container for filling upwardly open packaging containers with at least one opening flap for opening and closing a discharge opening for the product, the opening flap being moveable along a path between a closed position and an open position by means of a driving element. At least one delay device is provided by means of which the movement of the opening flap may be delayed on a section of the path.

Claims

1. A filling device with a discharge container for filling upwardly open packaging containers, the discharge container comprising: at least one opening flap being moveable along a path between a closed position and an open position by means of a driving element, at least one delay device comprising a throttle element, electrical brake, or spring by means of which the movement of the at least one opening flap may be delayed on a section of the path, and a switching element connected to the at least one delay device, wherein the switching element is configured to initiate the delay of the movement of the at least one opening flap produced by the at least one delay device as the driving element moves the at least one opening flap along the path.

2. The filling device according to claim 1, characterized in that the switching element comprises a lockable valve.

3. The filling device according to claim 1, characterized in that the delay device comprises a throttle element.

4. The filling device according to claim 3, wherein the throttle element is an air throttle.

5. The filling device according to claim 1, further comprising a product scale adjacent to the opening flap.

6. A method for filling upwardly open packaging containers by means of a filling device with a discharge container, the discharge container comprising: at least one opening flap being moved along a path between a closed position and an open position by means of a driving element, characterized in that the movement of the opening flap is delayed on a section of the path by means of at least one delay device comprising a throttle element, electrical brake, or spring, wherein the at least one delay device is connected to a switching element, wherein the switching element is configured to initiate the delay of the movement of the at least one opening flap produced by the at least one delay device as the driving element moves the at least one opening flap along the path.

7. A form-fill-seal-device comprising a bag forming device by means of which tube pieces may be separated subsequently from a tube material whose lower ends may be provided in each case with a base such as to build upwardly open bags, a filling device by means of which the upper openings of the bags may be closed, wherein the filling device comprises a discharge container comprising: at least one opening flap being moveable along a path between a closed position and an open position by means of a driving element, at least one delay device comprising a throttle element, electrical brake, or spring by means of which the movement of the at least one opening flap may be delayed on a section of the path, and a switching element connected to the at least one delay device, wherein the switching element is configured to initiate the delay of the movement of the at least one opening flap produced by the at least one delay device as the driving element moves the at least one opening flap along the path, retaining devices by means of which the bags may be retained within at least one of the devices mentioned above, and transport devices by means of which the bags may be carried individually between the individual devices mentioned above.

Description

(1) Further advantages, features and details of the invention become evident from the following description in which various example embodiments are discussed in detail with reference to the figures. Thereby, the features mentioned in the claims and in the description individually for themselves or any combination of mentioned features may be essential for the invention. Of course, throughout the disclosure, the claims and details which are described in relation with the method according to the invention, also apply in relation to the filling device according to the invention and/or to the form-fill-seal device according to the invention and vice versa such that reference is always made or may always be made reciprocally with respect to the disclosure concerning the individual aspects of the invention. The individual figures show:

(2) FIG. 1 a form-fill-seal machine

(3) FIG. 2 details of a filling device according to the invention

(4) FIG. 3 like FIG. 1, but with open opening flaps

(5) FIG. 4 a first structure of a filling device according to the invention

(6) FIG. 5 a second structure of a filling device according to the invention

(7) FIG. 6 like FIG. 5, but with a further moved piston

(8) FIG. 1 shows a form-fill-seal machine 1, which is often referred to briefly as FS machine, which is appropriate for molding, filling and closing of bags and to which the teachings of the present document may be advantageously applied. This device 1 comprises a support arm 2 on which a wrap 3 with a tubular film 4 rests. The tubular film 4 includes lateral folds which are not depicted in FIG. 1. The transport rollers 5, which in part may also be driven, induce a normally continuous unrolling of the tubular film 4. The lever 9 on which a load is applied by means of a piston-cylinder unit 10, which supports a deflecting roller 6 and in total is often referred to as dancing device, and the transport rollers 7, 8 as well as the feed roller pair 15 ensure collectively in a manner known per se that the tubular film 4 is moved further intermittently on its further transport path. The transport roller 8a is part of a register device 29 by means of which the length of the transport path of the tubular film 4 may be adapted to the format of the subsequent bags 27. For this purpose, the transport roller 8a is arranged displaceably with respect to the device 1. A spindle drive which is manually driven or driven by an electric motor and which is known per se is available for the displacement.

(9) The tubular film 4 is pushed through the welding jaws 33 of a cross-welding station 13 and through a cross-cutting station 16 by means of the feed roller pair 15. The tools of the cross-welding station 13 and of the cross-cutting station 16 may be moved in a manner which is not described in more detail, for example, by means of a parallelogram arrangement 14, in planes perpendicular to the feeding direction of the tubular film 4 towards the same and away from the same. Once the grippers 17 have gripped the tubular film 4, a tube piece 18 is separated from the tubular film 4 in the cross-cutting station 16 above the grippers 17. Concurrently, a cross weld is applied above the cutting edge at the tubular film 4 in the cross-welding station 13 which constitutes the base or the head side of the tube piece 18 to be formed in the next working cycle of the device 1. Accordingly, head seams are produced in the cross-welding station 13. However, generally, the production of the head or base seams may be performed not only by means of a cross-welding, although preferably by means of this, but also further joining methods, such as bonding, are conceivable.

(10) The grippers 17 carry the tube piece 18 to a handover point at which additional grippers 19 grip the tube piece 18 and convey it to a filling station 20. There, the tube piece 18 is handed over to stationary grippers 21 and is opened by the suckers 22 such that the product, which is conducted through the filling device 23, may enter the tube piece 18. Thereby, the tube piece 18 rests with its lower end on a conveyer belt 24 such that the tube piece 18 is not excessively charged along its longitudinal edges during the filling operation. Additional grippers 25 convey the filled tube piece to the head or base seam welding station 26 in which the tube piece 18 is closed with a head or base welding seam and thus constitutes a finished bag 27. Likewise, the closing of the tube piece 18 in its head region may be performed by means of another joining method. The finished bag 27 is guided by the conveyor belt 24 out of the device 1. Hereby, the bag 27 is normally much higher (in the y direction) than it is wide (in the x direction).

(11) FIG. 2 depicts now in more detail essential components of the filling device 23. The filling material 201 is provided in the dosing container 202. This means that the dosing container constitutes a reservoir for the filling material 201. Now it is necessary to separate a provided portion from this filling material for a bag. For this purpose, the discharge opening 203 of the dosing container is closed with a flap 204 which is moveable such as to release in part or completely the discharge opening. For this purpose, the flap 204 may be pivotally mounted about a pivoting axis 205, as shown in FIG. 2. With the open flap 204, the filling material 201 enters now the container 210. The latter may be provided with a scale which may measure the weight of the filling material inside the weighing container. This embodiment is shown in FIG. 2. The scale is represented by means of the two springs 211. These springs may be part of a spring scale. Of course, various other configurations of a scale and also various weighing methods are known to a person skilled in the art. Accordingly, the representation of a scale, and particularly of a spring scale, is not to be understood as a limitation.

(12) If the desired weight of the portion of the filling material for a bag is reached now, then the flap 204 is closed again. Thereafter, the opening flaps 212 of the weighing container in the arrow direction P are opened such that the weighed portion of the filling material may be dispensed into the bag 27 by means of an optional filling hopper 115. However, FIG. 2 shows the opening flaps still in their closed position.

(13) The opening and the closing of the opening flaps are performed by means of at least one driving element which in the present example embodiment is embodied as a piston-cylinder unit 213 which acts in two directions. Its cylinder 214 is pivotally connected to one of the two opening flaps, whereas the piston rod 216, which is connected to the piston 215 which is displaceable within the cylinder 214, is pivotally connected to the other opening flap. It should be noted that such piston-cylinder units may also be pivotally connected in another way. Thus, a piston-cylinder unit may be pivotally connected to an opening flap and the machine frame. Other driving types are also conceivable at this point.

(14) In FIG. 3, essentially the same components as in FIG. 2 are depicted, although the opening flaps are now in their open position. At the same time, optional end stops 217 can be seen at which the opening flaps 212 may rest in their open position.

(15) In FIG. 4, the piston-cylinder unit 213 with a driving element which is filled with fluid can be seen which is part of an advantageous embodiment of the invention. The piston 214 comprises a first volume 220 and a second volume 221 which are separated from each other by the piston 215. The volume 220 is connected to a fluid line 222 such that a fluid subjected to the excess pressure Pi may be introduced in the volume by means of a corresponding position of the directional valve 223 in which the fluid line 222 begins. For this reason, the piston 215 is displaced in the direction K, the fluid in the volume 221 being ejected and entering the fluid line 224 which at a branching point splits into a first fluid line branch 225 and into a second fluid line branch 226. The fluid line branch 226 ends in a switching valve 227 which has two switching positions. In a first switching position, the fluid stream is blocked such that the fluid cannot stream out of the fluid line. In a second switching position, the fluid may exit freely, i. e., without any resistance, from the fluid line 226. If the switching valve 227 is in the first switching position (fluid stream is blocked or interrupted), the fluid flows through the fluid line branch 225 in which a throttle 228 is arranged which constitutes a resistance. Preferably, the throttle 228 or its resistance is adjustable. From the throttle 228, the fluid enters into the directional valve 223 which is switched such that the fluid may be deflected, for example, to the environment, or into a fluid reservoir. The switching of the switching valve 227 to the first switching position and the conducting of the fluid through the throttle 228 which is caused this way induces a counterforce for the piston 215 which is slowed down this way. A switching of the switching valve 227 from the second switching position to the first switching position which is performed during the movement of the piston allows to perform the first part of the movement of the piston, which lasts until said switching of the switching valve, with a speed v.sub.1 and to perform the second part of the movement, which starts as from the switching of the switching valve, with a speed v.sub.2 which may be constantly reduced until the piston has reached its end position. Preferably, the speed v.sub.1 is essentially constant or constantly increasing. Moreover, it is provided that v.sub.1 is higher than v.sub.2.

(16) The timing of the switching of the switching valve 227 may be time-controlled and/or path-controlled. In the first case, the switching valve may be switched after a time period in which the piston is moving. For this purpose, a control unit, which is not depicted, is available which preferably triggers first the start of the movement of the piston and subsequently, once said time period has expired, the switching of the switching valve 227 from the second switching position to the first switching position. In the second case, a sensor 229 is provided which is arranged for sensing at least the exceeding of a point by the piston. The control unit may control the switching of the switching valve 227 immediately after a corresponding signal of the sensor 229.

(17) In the example embodiment of FIG. 4, the configuration of a driving element which is filled with a fluid has been depicted only for the case of the opening of the opening flaps. Of course, such a configuration may also be provided additionally or alternatively for closing the opening flaps. For this purpose, first, the directional valve 223 may be switched such that the fluid subjected to excess pressure may be conducted into the volume 221. Moreover, the fluid line 222 would be provided with a branching point, a first branch conducting through a throttle to the directional valve 223 and a second branch conducting to a switching valve which is designed analogous to the switching valve 227 and also has a corresponding effect. For a combined operation it is advantageous when the throttles only offer resistance to the fluid in one direction. In the opposite direction there is no or only a low throttling effect. Likewise, a time and/or path control may be realized in a manner which has been discussed above in relation to the configuration shown in FIG. 4.

(18) Preferably, a gas, particularly air, is provided as a fluid.

(19) FIG. 5 shows another example embodiment of the invention. Here, the displacement of the piston is performed as in the example embodiment of FIG. 4 by means of the introduction of a fluid under overpressure into the volume 220 or 221. The delay, i. e., the slowing down of the movement of the piston may also be performed by means of a mechanical device, for example, a spring element, which acts directly or indirectly on the piston rod and/or on the opening flap, whereas the effect of the mechanical device occurs only in the second part of the movement. The effect of this mechanical element is discussed now by means of the spiral spring shown in FIG. 5 as an example. First, the element which is also moved by the moving piston (in this case the piston rod 216) is not in contact with the spiral spring. In the second part of the movement, the piston rod with its end region (in this case represented by way of example as the plate 231) comes into contact with the spring 230, which is depicted in FIG. 6. The force which is necessary for compressing the spring slows down the movement of the piston 215. The spring 230 itself may be fastened to a fastening element 232 which may be stationary with respect to the frame of the filling device.

(20) However, it is advantageous when the fastening element may be moved away from the cylinder in the direction of the arrow F so as to reduce the spring force, the distance between the cylinder and the fastening element 232 being increased. Thereby, the movement profile of the fastening element 232 has to be adapted to the movement pattern of the piston 215 such that the desired delay is produced.

(21) The mechanical device may also be embodied in other ways. Likewise, an electrical device or an electromagnetic device may be provided which acts on the piston and/or the piston rod so as to slow down the piston in the second part of the movement of the piston. Here, an eddy current brake as well as a switchable electromagnet are also conceivable.

(22) TABLE-US-00001 Reference sign list  1 Device for producing and filling bags  2 Support arm  3 Wrap  4 Film/tubular film/plastic tube  5 Transport roller  6 Deflecting roller  7 Transport roller  8, 8a Transport roller  9 Lever  10 Piston-cylinder unit  11  12  13 Cross-welding station  14 Parallelogram arrangement  15 Feed roller pair  16 Cross-cutting and cross-welding station  17 Grippers  18 Flexible tube piece  19 Grippers  20 Filling station  21 Stationary gripper  22 Suckers  23 Filling device  24 Conveyor belt  25 Grippers  26 Head or base seam welding station  27 Bag  28  29 Register device  30  31  32  33 Support surface  34 Dashed line “height (y) of bag opening”  35 Arrow distance of opening 62 of the tube piece 18 to the support surface 58 in the vertical direction  36 Symmetry line of the filling nozzle 23  37 Vibrator 115 Filling hopper 201 Filling material 202 Dosing container 203 Discharge opening 204 Flap 205 Pivoting axis 206 207 208 209 210 Weighing container 211 Springs 212 Opening flap 213 Piston-cylinder unit 214 Cylinder 215 Piston 216 Piston rod 220 First volume 221 Second volume 222 (First) Fluid line 223 Directional valve 224 (Second) Fluid line 225 Fluid line branch 226 Fluid line branch 227 Switching valve 228 Throttle 229 Sensor 230 Spring 231 Plate 232 Fastening element F Arrow, direction of movement of the fastening element K Arrow, direction of movement of the piston P Arrow, opening direction of the opening flaps x Transport direction of the bags y Direction orthogonal to the directions x and z z Direction of gravity