Apparatus and method for forming packaging film ruffles in tubular bag packaging

Abstract

The invention relates to a device and a method for folding a packaging film in the region of a transverse sealing seam (Q) of a packaging unit (V) formed in a tubular bag packaging machine. The folding device has two fold folding devices (100; 200); 300), in the region where the transverse sealing seam (Q) is to be formed, a fold folding device (100; 300) is arranged on the outside of each side (S) of the packaging unit (V) to be formed, 200); 300) for a vehicle. The two fold folding devices (100; 200); 300) comprises: at least one folding finger (114, 124; 224, 234; 324, 334) which, in the region of the transverse sealing seam (Q) to be formed, is joined laterally from the outside into the side (S) of the packaging unit (V) to be formed and which, at least in part, presses the side (S) inwards perpendicular to the conveying direction (F) in the direction of the transverse sealing seam (Q) to be formed, in order to thereby form a packaging film fold (Z); and at least two coupling mechanisms (110, 120; 220, 230; 320, 330), wherein each coupling mechanism (110, 120; 220, 230; 320, 330) comprises a movable first coupling element, in particular a crank element (111, 121; 221, 231; 321, 331), a movable second coupling element, in particular a rocker element (112, 122; 222, 232; 322, 332), and a connecting element (113, 123; 124) connecting the first coupling element and the second coupling element to each other. 223, 233; 323, 333) for a motor vehicle. Herein, each one of the folding fingers (114, 124; 224, 234; 324, 334) is attached to the at least two coupling mechanisms (110, 120; 220, 230; 320, 330), and a connecting element (113, 123; 223, 233; 323, 333) of the housing. The invention also relates to a tubular bag packaging machine comprising a folding device according to the invention, and to a packaging unit formed using such a folding device and / or using such a tubular bag packaging machine and / or by using a method according to the invention.

Description

Technical Field

[0001] The invention relates to a device and a method for folding a packaging film in the region of a transverse sealing seam of a packaging unit formed in a tubular bag packaging machine. The invention further relates to a tubular bag packaging machine comprising a folding device according to the invention. The invention further relates to a packaging unit formed with a folding device according to the invention and / or with a tubular bag packaging machine according to the invention and / or by using a method according to the invention. Background Art

[0002] The present invention relates in principle to packaging products in packaging films by means of tubular bag packaging machines, in particular horizontal tubular bag packaging machines. In this article, block products or sheet goods are pushed into a film tube, which is then divided into individual packaging units and sealed. Within the scope of the present invention, in principle all conceivable packaging materials can be used as packaging films, which packaging films include, for example, plastic films and paper packaging. In this type of tubular bag packaging machine, the packaging film is supplied as an endless belt and is placed or folded around the product to be packaged and sealed. Then the single packaging unit separated subsequently is taken down. The method allows a process to be realized that is fast and continuously running, wherein only a single packaging material (packaging film) is required, and wherein the resulting packaging unit is usually more or less sealed, preferably airtightly sealed, depending on the application. Specifically, airtight sealing can be achieved in a so-called heat sealer. This type of tubular bag packaging machine is used, for example, in the field of packaging candies, such as chocolate tablets, chocolate bars, cereal bars, etc., which usually have a rectangular or cubic shape. However, in addition to this type of product in the candy industry, other products, such as industrial or technical products, can also be conceived.

[0003] With this type of tubular bag machine, usually first a longitudinal sealing seam is produced, which extends in the conveying direction of the machine, and with the help of which the two sides of the supply film tube wrapped around the product are connected to each other, in particular sealed. Therefore, the individual products are pushed into the film tube to a certain extent one after another, and then arranged in the film tube at regular distances from each other along the conveying direction. With the help of a suitable transverse sealing device or transverse sealing station, a transverse sealing seam extending transversely to the conveying direction of the machine is then formed in the film tube between two consecutive products. In this case, the transverse sealing station usually has a knife device, with the help of which the individual packaging units are separated from each other along the transverse sealing seam. In this article, the transverse sealing seam is divided into two parallel transverse sealing seams, specifically, the rear transverse sealing seam of the first preceding packaging unit shown in the conveying direction, and the front transverse sealing seam of the second packaging unit shown in the conveying direction. With the help of these closed transverse sealing seams and longitudinal sealing seams, the corresponding packaging unit containing the product is then completely formed and particularly tightly sealed.

[0004] This type of packaging unit V is shown in plan view in FIG. 1a. In the case of this packaging unit V, the length LQ of the transverse sealing seam Q (i.e., the extent of the transverse sealing seam Q transverse to the conveying direction F) is usually greater than the width BV of the actual packaging unit V (i.e., the extent of the packaging unit V transverse to the conveying direction). In this article, the width BV of the packaging unit V corresponds substantially to the actual width of the packaged product, because the packaging film is usually placed closely around the product. Specifically, the length LQ of the transverse sealing seam Q usually corresponds to the sum of the width BV of the product or packaging unit V and the height of the product or packaging unit V, wherein the height of the product extends perpendicular to the conveying plane. This length LQ of the transverse sealing seam Q is due to the fact that during the folding of the film around the product and during the formation of the transverse sealing seam Q, the excess film material in the region of the two side ends of the transverse sealing seam Q or in the transition region from the corresponding side ends of the transverse sealing seam Q to the corresponding side S of the packaging unit V is bent laterally or outwardly and then protrudes laterally (see FIG. 1a).

[0005] Figure 1b The packaging unit V is shown in a schematic cross-sectional view along the line AA in FIG. 1a. Thus, the section AA extends along the transverse sealing seam Q. Thus, from Figure 1b As can be seen in the figure, in the transverse sealing seam Q, essentially two layers of the packaging film are superimposed on each other (see Figure 1b In contrast, in the region of the longitudinal sealing seam L, i.e., in Figure 1b In the region (c) where the longitudinal sealing seam L and the transverse sealing seam Q intersect, substantially four layers of the packaging film are superimposed on one another in the transverse sealing seam Q.

[0006] The above-mentioned lateral protrusion of excess film material in the two side end regions of the transverse sealing seam Q is generally undesirable, since this causes interference during the further processing and / or transportation and / or packaging of the formed packaging unit. Therefore, the lateral film protrusion can cause disadvantages or problems, in particular in the case of products or packaging units to be packaged in cardboard, because these products or packaging units can only be stacked or layered in a space-saving manner within a limited range, which is undesirable for forming a secondary packaging or outer packaging that is as compact as possible. In addition, the products to be stacked, for example in an outer cardboard packaging, can remain suspended from each other and entangled with each other during their transportation, thus hindering an orderly arrangement in the packaging cardboard. Finally, the lateral protrusion of excess film material is also disadvantageous in terms of an attractive product design or an aesthetic product display.

[0007] In order to avoid the above-mentioned disadvantages and problems, it is known to avoid the above-mentioned lateral protrusion of excess film material in the region of the transverse sealing seam Q during the production of the packaging units in the tubular bag machine. For this purpose, before the sealing of the transverse sealing seam Q, an additional folding of the packaging material or packaging film is performed in the region of the two side ends of the transverse sealing seam Q. Here, the film tube is pressed in laterally on both sides so that the width BV of the packaging unit V is the same or uniform over the entire length of the packaging unit V in the conveying direction, i.e. also including the front and rear transverse sealing seams Q. In other words, therefore, after the sealing of the transverse sealing seam Q, i.e. when the packaging unit V is finished, the length LQ of the transverse sealing seam Q extending transversely to the conveying direction F of the tubular bag machine is substantially equal to the width BV of the packaging unit V extending transversely to the conveying direction F or to the actual width of the product packaged therein. Figure 2a In the floor plan and Figure 3 A packaging unit V of this type is shown in a perspective view.

[0008] Figure 2b Along the Figure 2a The schematic cross-sectional view taken along line BB in FIG. 1 shows such a packaging unit V. Figure 1b , section BB extends along the transverse sealing seam Q. Thus, Figure 2b As can be seen in the figure, in the transverse sealing seam Q, essentially two layers of the packaging film are again superimposed on each other (see Figure 2b In addition, as in Figure 1b In the same way, in the region of the longitudinal sealing seam L, that is, in Figure 2b In the region (c) where the longitudinal sealing seam L in the packaging film intersects the transverse sealing seam Q, essentially four layers of the packaging film are also superimposed on each other in the transverse sealing seam Q. However, unlike Figure 1b The difference is that in Figure 2bIn the case of the packaging unit V in FIG. 1 , at the side ends of the transverse sealing seam Q, i.e., at Figure 2b In the regions (d) and (e) in FIG. 1 , essentially four layers of the packaging film are now also placed one on top of the other.

[0009] In order to obtain such a shape of the transverse sealing seam Q, before sealing the transverse sealing seam Q, the film tube is pressed laterally or inwardly in the region of each side end of the transverse sealing seam Q and / or in the region of the transition from the respective side end of the transverse sealing seam Q to the respective side S of the packaging unit V. In this case, the film tube is laterally engaged or pushed in from the outside by a suitable device or tool, but the film tube is not punctured or damaged in another way. In this case, the film tube is formed and / or folded so that after sealing the transverse sealing seam Q, a packaging film hem Z is formed in the region of each side end of the transverse sealing seam Q or in the region of the transition from the respective side end of the transverse sealing seam Q to the respective side S of the packaging unit V, so that the packaging film is folded in the region of each side end of the transverse sealing seam Q so that it is superimposed on one another in four layers (see Figure 2b In this case, the packaging film hem Z specifically each forms the region in which the film transitions from the lateral four-layer end of the transverse sealing seam Q to the corresponding essentially vertically oriented side of the packaging unit V, wherein the film extends essentially in one layer and in a planar or uniform manner on the side S (see Figure 3 ).

[0010] In this way, the above combined with Figure 1a and Figure 1b The excess film material described which is produced during the folding of the film around the product and during the formation of the transverse sealing seam Q is at least partially pressed laterally into the transverse sealing seam Q and / or the packaging film fold Z and is to a certain extent deposited therein.

[0011] The above-described process of forming the hem Z of the packaging film is also referred to as hem folding. In the field of (horizontal) tubular bag packaging machines, this process is an additional process step for forming a "hem-type" packaging unit V, in which the packaging width BV is continuously (i.e. along the entire length of the packaging unit V in the conveying direction F, including the transverse sealing seam Q) adapted to the product width (see Figure 2a and Figure 3 ). Based on geometrical relationships, it is obvious here that the joining depth or piercing depth of the hem fold usually corresponds essentially to half the height of the product or packaging unit V, wherein the height of the product extends perpendicularly to the conveying plane.

[0012] For the sake of clarity, the hem folding and the elements associated therewith are shown and described in most cases only on one side, i.e. one side of the packaging unit V. However, it goes without saying that this is a symmetrical process and that the hem folding and the associated components are provided on both sides of a practical packaging machine, i.e. both sides of the packaging unit V. Therefore, the components of the hem folding on one side of the packaging unit V are usually also located on the respective other side of the packaging unit V in a mirrored arrangement and design in practice.

[0013] Various devices and methods are known for producing the above-mentioned "frilled" packaging units V.

[0014] In the case of pneumatic hem folders, nozzles arranged on both sides are actuated in a timed manner in order to press the film tube in front of the transverse sealing station on both sides by means of compressed air. However, this method leads to undefined folds and / or extra folds at high cycle rates, i.e., an overall irregular hem fold and packaging form. In addition to the unfavorable appearance of the resulting packaging unit and the limited processing speed and timing, the use of compressed air is in principle cost-intensive and therefore disadvantageous.

[0015] An alternative device for producing a "frilled" packaging unit V is realized by a mechanical frilling device, by which the packaging film is mechanically pressed in. Firstly, a double crank or parallel crank frilling mechanism 10 is described for this purpose, which is shown in FIGS. Figure 5a to Figure 5c Schematically shown in FIG. Such a four-component coupling mechanism or hem folding mechanism 10 is in principle composed of a first crank element 11 mounted on a first bearing 11a in a 360° rotational manner, a second crank element 12 mounted on a second bearing 12a in a 360° rotational manner, and a coupling element 13 connecting the two crank elements 11, 12 to each other. A folding plate, a folding finger or a piercing finger 14 with a tip 15 is attached to the coupling element 13, and the tip is also called a coupling point. If the two crank elements 11, 12 are driven by a suitable drive device 16 or a so-called overdrive device, the tip 15 is therefore moved on a circular path or a coupling point path 17. During this circular movement, the tip 15 alternately engages in the packaging film (or pierces the packaging film, but does not penetrate the film) so as to press into the film to form the packaging film hem Z, or retracts out of engagement with the packaging film, as described in more detail below.

[0016] As shown in FIG. 4 , in the case of the above-described hem folding mechanism 10, the guide mechanism is realized by parallel cranks, and the folding fingers 14 are fixed to the coupling 13. In this case, the two cranks 11, 12 usually have to be driven in the same way. This is usually achieved by a belt drive (overdrive 16). Therefore, the associated connection point path 17 on which the tip 15 of the folding finger 14 moves is always circular. Since the theoretically precise penetration depth of the folding finger 14 in the packaging film corresponds to half the product height, the hem folding mechanism 10 must be adjusted according to the corresponding product width and height. This is usually ensured by replaceable folding fingers 14.

[0017] Figure 5a to Figure 5c 4 shows schematically the movement sequence of the parallel crank hem folding mechanism 10, and in particular shows the engagement and disengagement of the folding fingers 14 with the packaging film between two consecutive products P, the two products P in Figure 5a to Figure 5c The drawing plane corresponds here to the conveying plane of the packaging machine. Figure 5a Specifically shown is the folding finger 14 piercing the film tube, Figure 5b The synchronous advancement of the folding fingers 14 and the film tube is specifically shown, and Figure 5c In particular, the disengagement of the folding fingers 14 from the film tube is shown.

[0018] The two crank elements 11 , 12 rotate, for example, clockwise about their bearings 11 a , 11 b and the tip 15 of the folding finger 14 thus moves clockwise on a circular path 17 . Figure 5a to Figure 5c The dash-dotted line 18 in φ represents the axis of symmetry of the mirror-image arrangement of the corresponding components of the corresponding hem folding mechanism on the other side of the product P or packaging unit V.

[0019] To create the hem fold, the folding plates or fingers 14 are controlled so that the packaging material (packaging film) is pressed between the circulating products P (see Figure 5a The actual process of folding the film ends when the folding fingers 14 have reached their maximum penetration depth (see Figure 5b ). During the creation of the hem fold, the tip 15 (joining point K) of the folding finger 14 moves substantially synchronously with the film web. Thus, the movement of the tip 15 is substantially caused by the tip 15 being perpendicular to the product P or the packaging film at Figure 5a to Figure 5c The superposition or combination of the velocity component vN in the conveying direction F extending from left to right in the tip 15 and the velocity component vF along or parallel to the conveying direction F (i.e., the speed at which the film web moves along the conveying direction F). Therefore, Figure 5a and Figure 5b The following velocity vectors are shown: vF = film velocity; vK = junction velocity; vN = normal velocity. Figure 5bThe time of the maximum penetration depth of the tip 15 or the connection point K in the packaging film is shown.

[0020] When the tip 15 is disengaged from the packaging film during its further movement on the circular path 17 or is retracted or leaves the film tube (see Figure 5b to Figure 5c The subsequent movement range (from Figure 5c to Figure 5a The transition from the hem folding mechanism to the tip 15 of the folding finger 14 is related to the return of the tip 15 to a position in which it can engage in the film between the next two products P. This range of movement is also referred to as the return stroke. This range of movement is usually irrelevant to the actual hem folding process. However, it must be ensured that the tip 15 of the hem folding mechanism is in the Figure 5a The position is available again in time to enable piercing between the next two products P.

[0021] Due to the mechanical contact between the folding plates or folding fingers 14 and the packaging components during piercing, undesirable damage to the packaging material may occur at relatively high processing speeds. Thus, for example, the packaging material may be pierced or torn. This problem is caused in particular by the normal speed vN of the folding fingers 14 during the engagement or piercing of the film tube (see Figure 5a The normal velocity vN in this article refers to the velocity of the folding finger 14 relative to the product P or the packaging film. Figures 5a to 5c The speed component perpendicular to the conveying direction F extending from left to right in the folding finger 14 is thus adjusted by adjusting the connection point path 17, in particular by changing the connection point path 17 to produce the effect of reducing the component of the normal speed vN, the performance can be improved so that a more product-friendly piercing of the folding finger 14 is achieved. This is achieved, for example, by the mechanism described below.

[0022] Since the parallel crank hem folding mechanism 10 described above allows only a circular connection point path 17, a crank rocker hem folding mechanism 20 as schematically shown in FIG6 will be described below as an alternative connection mechanism. As before, in this known mechanical hem folding device, the packaging film is also mechanically pressed in to form the packaging film hem Z.

[0023] As shown in FIG6 , this four-member crank rocker hem folding mechanism 20 is in principle composed of a crank element 21 mounted on a first bearing 21a in a 360° rotational manner and a rocker element 22 rotatably mounted on a second bearing 22a. The rocker element 22 does not rotate a full 360°, but only oscillates or swings back and forth within a specific angular range between two end positions. The mechanism also includes a coupling element or connecting element 23, which connects the crank element 21 and the rocker element 22 to each other. A folding plate, a folding finger or a piercing finger 24 with a tip 25 is attached to the coupling element 23, which is also referred to as a coupling point. In the case of such a mechanism, usually only the crank element 21 is driven by an appropriate transmission 26 and specifically rotates 360° therein. The effect is that, due to the connection via the coupling element 23, the rocker element 22 performs an oscillating movement within a predetermined angular range. Therefore, the tip 25 of the folding finger 24 moves on a path (coupling point path) 27 that is usually no longer a circular path. By choosing the dimensions (e.g. length) of the components or elements, the actual resulting shape of this path can be modified in a suitable manner. It should be noted that the paths in the figures are shown only qualitatively or by way of example and not to scale. During this movement, the tip 25 alternately engages with or penetrates the packaging film so as to press into the film to form the packaging film hem Z, or retracts out of engagement with the packaging film.

[0024] In the embodiment shown in FIG. 6 , the crank element 21 rotates clockwise, for example, according to the indicated arrow direction. However, a counterclockwise direction of rotation is also conceivable. Thus, the rocker element 22 oscillates back and forth according to the indicated double arrow. Due to this movement system, the tip 25 of the folding finger 24 moves on the shown connection point path 27. It goes without saying that a suitable reversal or change of the described or shown movement direction is also conceivable. As mentioned, the drawings should only be understood qualitatively and / or schematically.

[0025] In the case of a crank-rocker hem folding mechanism of this type, the possible connection point paths are usually described by a sixth-order three-circle function, so that the shape of the connection point paths can be adjusted in a variety of ways in the design of the mechanism. As a result, the normal velocity vN of the folding finger 24 can be significantly reduced and the performance associated therewith can be improved. In summary, it should be noted that in order to control the position of the folding finger 24 or its tip 25, the kinematics of the connection mechanism must be taken into account. In addition, the rotational movement of the crank element 21 is usually not uniform, that is, the acceleration or deceleration of the rotational movement of the crank element 21 can be carried out in phase. This is also used in particular to enable the tip 25 of the folding finger 24, after it has been engaged in the packaging film between two products P, to return in a time-accurate and position-accurate manner to a position in which it can then be engaged again in the packaging film between the next two products P (this position corresponds in principle to Figure 5aThe same also applies to the above-mentioned parallel crank hem folding mechanism 10 accordingly.

[0026] In principle, for both hem folding devices 10, 20 described above, the product width and the product height are essentially decisive for the actual process of creating the hem fold (see accordingly from Figure 5a to Figure 5b arrive Figure 5c However, with regard to the continuous operation of the tubular bag machine, the return stroke of the folding fingers into the position in which they can engage in the film between the next two products should also be taken into account (see accordingly from Figure 5c to Figure 5a In this context, the product length refers to the length of the product in the conveying direction of the packaging machine. In the case of long products, a slow return stroke of the folding fingers is possible or necessary, which can also be achieved by an additional pause (i.e. the folding fingers stop in phase). In contrast, in the case of short products, a fast return stroke of the folding fingers is usually necessary in order to be available again in time at the starting position or initial position (corresponding to Figure 5a ) for the next engagement in the film. This represents a limiting factor in the performance of known packaging machines with hem folding.

[0027] The variable and in some cases high speeds associated with the said movement sequence of the coupling mechanism and therefore the significant accelerations or significant decelerations in the various phases lead to corresponding loads on the transmission or drive motor driving the relevant components of the coupling mechanism. This therefore significantly limits the possible cycle rate of the hem folding and therefore the overall performance of the known packaging machine. Summary of the invention

[0028] The object of the present invention is therefore to overcome the above-mentioned disadvantages. In particular, by means of the present invention, the generation speed or cycle rate of the hem folding in a tubular bag packaging unit is increased, in particular in the case of packaging relatively short products, and the performance of the packaging machine with hem folding is thus improved. In particular, the present invention allows the components of the hem folding coupling mechanism to undergo significant acceleration and / or significant deceleration in phase during the movement, which leads to the avoidance of correspondingly large loads on the transmission device driving the relevant components as in the prior art.

[0029] According to the invention, this object is achieved by a folding device for folding a packaging film in the region of a transverse sealing seam of a packaging unit formed in a tubular bag packaging machine according to claim 1 and a corresponding method according to claim 16. The mentioned object is also achieved by a tubular bag packaging machine according to claim 17 and a packaging unit formed from a packaging film according to claim 18.

[0030] Therefore, the present invention provides a folding device for folding a packaging film in the area of ​​a transverse sealing seam to be formed of a packaging unit to be formed in a tubular bag packaging machine, wherein the transverse sealing seam extends basically in a conveying plane and extends perpendicularly to the conveying direction of the tubular bag packaging machine, wherein the packaging unit to be formed has two side surfaces, which extend basically along the conveying direction and extend perpendicularly to the conveying plane of the tubular bag packaging machine, and wherein the folding device has two hem folding devices, wherein in the area of ​​the transverse sealing seam to be formed, each hem folding device is arranged basically on the outside of each side surface of the packaging unit to be formed. In the folding device according to the present invention, each of the two hem folding devices also includes the following features: at least one folding finger, which is configured and movable so that it laterally engages into the side of the packaging unit to be formed from the outside in the area where the transverse sealing seam is to be formed and at least partially presses the side inward perpendicular to the conveying direction substantially along the direction of the transverse sealing seam to be formed; and at least two connecting mechanisms, each of which has a movable first connecting element, a movable second connecting element and a connecting element, which is configured so that it connects the first connecting element and the second connecting element to each other; wherein each folding finger is attached to one of the connecting elements of the at least two connecting mechanisms.

[0031] Although the above-mentioned known mechanical hem folding mechanisms 10 and 20 (see Figure 5a to Figure 5c and FIG. 6 ) each comprise exactly one coupling mechanism, each having two movable coupling elements and one connecting element connecting them, and further comprising exactly one folding finger each attached to the connecting element, but according to the invention it is provided that the hem folding mechanism or the hem folding device comprises at least one folding finger and at least two coupling mechanisms. According to the invention, in principle, it is therefore possible to provide in the hem folding mechanism any number of folding fingers and any number of two or more coupling mechanisms, wherein each folding finger is attached to each coupling mechanism in the coupling mechanism. According to the invention, in principle, it is also possible that there are fewer folding fingers than coupling mechanisms and / or that the number of folding fingers is at most equal to the number of coupling mechanisms.

[0032] If there are a plurality of folding fingers, due to the movement of the coupling mechanism, the folding fingers successively and alternately engage between two consecutive packaging units to be formed in the tubular bag machine in the packaging film and respectively press the latter inwards in the extension direction of the transverse sealing seam to be formed. The transverse sealing seam is then sealed and the respective packaging unit is thereby closed. Finally, a packaging film hem is thus respectively formed at each of the four corners of the finished, substantially cuboid packaging unit, which is respectively separated from the supplied packaging film tube.

[0033] In a preferred embodiment of the folding device according to the invention, each hem folding device has two folding fingers and two coupling mechanisms, wherein one folding finger is respectively attached to one coupling mechanism.

[0034] Compared with the known hem folding mechanisms 10 and 20 (see Figure 5a to Figure 5c Compared to FIG. 6 ) where the hem folding mechanisms each comprise a coupling mechanism with a folding finger, in this embodiment of the hem folding device according to the invention, two interacting coupling mechanisms, which are preferably arranged in principle parallel to one another, are provided with one folding finger each. As a result, only every other hem fold is performed by one of the two coupling mechanisms or by the same coupling mechanism, i.e. the two coupling mechanisms and their corresponding folding fingers alternate in the continuous formation of the hem fold. In this way, the cycle rate of each individual coupling mechanism is halved, while the hem folding device as a whole achieves the full cycle rate required for the continuous formation of individual packaging units.

[0035] Thus, the above-mentioned high speed or the step-by-step alternation of the components of the coupling mechanism and the resulting load on the transmission device, which is given in the prior art, is avoided or at all costs reduced. Thus, in particular in the case of short products, a highly dynamic or rapid return stroke of the individual folding fingers into their initial position for the respective next folding operation, as on the other hand given in the prior art, can ultimately be omitted, or such a return stroke can be carried out correspondingly slower and therefore more gently, since each individual folding finger has more time to return to its initial position, taking into account the presence of the second coupling mechanism.

[0036] As described above, according to the invention, this method can in principle be extended to any number of coupling mechanisms, wherein each hem-folding device has an associated folding finger. The individual folding fingers are successively engaged in a phase-shifted manner in the packaging film corresponding to the number of coupling mechanisms, wherein each individual folding finger must be used less frequently during the film joining process. As a result, the cycle rate of the respective individual coupling mechanism is reduced, while the hem-folding device as a whole achieves the full cycle rate required for the continuous formation of individual packaging units. As a result, the performance of the hem-folding device and thus the performance of the entire tubular bag packaging machine can be increased, because, in general, due to the plurality of coupling mechanisms in the hem-folding device, the cycle rate or the speed of the hem-folding can be increased accordingly.

[0037] With the folding device according to the invention, higher circulation rates can be achieved in general over the entire specification range, both for short and long products. In this context, the specification range is generally understood to be the permissible dimensions of the product to be packaged, i.e. the minimum and / or maximum length / height / width of the product.

[0038] It goes without saying that as the number of coupling mechanisms and folding fingers per hem folding device increases, the mechanical design, spatial arrangement and control and / or regulation of the (mechanical) components become correspondingly more complex. Due to the movement system and / or combined movement sequence of the components and taking into account the fact that a plurality of folding fingers must in principle always engage in the packaging film at essentially the same position and / or in the same plane in the conveying path, penetration or overlap of the movement paths and / or collisions of the components must be prevented during the movement of the components.

[0039] In a first embodiment of the folding device according to the invention, at least one of the at least two coupling mechanisms in each of the hem folding devices is designed so that the first coupling element and the second coupling element are each a crank element, which is designed so that it can rotate 360° around an axis, wherein the axes of the first crank element and the second crank element are substantially parallel to each other and extend perpendicularly to the conveying plane and perpendicularly to the conveying direction of the tubular bag packaging machine. Thus, at least one coupling mechanism corresponds to the above description in conjunction with FIGS. 4 and 5. Figure 5a to Figure 5c Described is a parallel crank hem folding mechanism / coupling mechanism 10. Depending on the number of coupling mechanisms interacting in the hem folding device, in this embodiment, one, more or all coupling mechanisms may be configured as described above, ie as parallel crank mechanisms.

[0040] In a second embodiment of the folding device according to the invention, at least one of the at least two coupling mechanisms in each of the hem folding devices is configured such that the first coupling element is a crank element, which is configured such that it can rotate 360° around an axis, and the second coupling element is a rocker element, which is configured such that it can rotate around an axis and oscillate back and forth between two end positions, wherein the axis of the crank element and the axis of the rocker element are substantially parallel to each other and extend perpendicularly to the conveying plane and perpendicularly to the conveying direction of the tubular bag packaging machine. Thus, at least one coupling mechanism corresponds to the crank-rocker hem folding mechanism / coupling mechanism 20 described above in conjunction with FIG. 6. Depending on the number of coupling mechanisms that interact in each hem folding device, in this embodiment, one, more or all coupling mechanisms may be configured as described above, i.e., configured as crank-rocker mechanisms.

[0041] In the combination of the above-mentioned first and second embodiments of the folding device according to the present invention, in the hem folding device, at least one coupling mechanism can therefore also be configured as a parallel crank mechanism, and at least one coupling mechanism is configured as a crank rocker mechanism. Therefore, in the case where there are exactly two coupling mechanisms in the hem folding device, one parallel crank mechanism is combined with one crank rocker mechanism. If more than two coupling mechanisms are provided in the hem folding device, one or more parallel crank mechanisms can be combined with a corresponding arbitrary number of one or more crank rocker mechanisms.

[0042] In a preferred variant of the above-described embodiment of the folding device according to the invention, it is provided that each of the two hem folding devices has exactly two coupling mechanisms, wherein each of the two coupling mechanisms is configured such that the first coupling element is a crank element, which is configured such that it can rotate 360° around an axis, and the second coupling element is a rocker element, which is configured such that it can rotate around an axis and oscillate back and forth between two end positions, wherein the axis of the crank element and the axis of the rocker element extend substantially parallel to each other and perpendicular to the conveying plane and perpendicular to the conveying direction of the tubular bag packaging machine. Thus, each of the two coupling mechanisms corresponds to the crank-rocker hem folding mechanism / coupling mechanism 20 described above in conjunction with FIG. 6 .

[0043] Preferably, in this variant, it is also provided that the crank element of the first coupling mechanism is substantially identical to the crank element of the second coupling mechanism, i.e. both crank elements have substantially the same size, in particular the same length, and the rotation axis of the crank element of the first coupling mechanism is identical to or coincides with the rotation axis of the crank element of the second coupling mechanism. Furthermore, it is preferably provided in this variant that the rocker element of the first coupling mechanism is substantially identical to the rocker element of the second coupling mechanism, i.e. both rocker elements have substantially the same size, in particular the same length, and the rotation axis of the rocker element of the first coupling mechanism is identical to or coincides with the rotation axis of the rocker element of the second coupling mechanism. Furthermore, it is preferably provided in this variant that the folding fingers of the first coupling mechanism are substantially identical to the folding fingers of the second coupling mechanism, i.e. both folding fingers have substantially the same size, in particular the same length.

[0044] In this way, the tips or connection points of the two folding fingers move on the same path (connection point path). As described above in conjunction with the crank rocker hem folding mechanism / connection mechanism 20 shown in Figure 6, this path can have different shapes, wherein the actual resulting shape of the path can be modified in an appropriate manner by selecting the dimensions (e.g., length) of the components or elements of the connection mechanism. Therefore, the two folding fingers can be engaged successively or alternately and in a phase-shifted manner corresponding to their preferably regular angular distance at substantially the same position in the packaging film. However, for this purpose, the components of the connection mechanism must additionally be configured so that they do not collide with each other during their movement and no penetration of their movement path occurs.

[0045] If each of the two hem folding devices has more than two coupling mechanisms, the above for the two coupling mechanisms applies accordingly. Here, the crank elements of all coupling mechanisms are substantially identical to one another, the rocker elements of all coupling mechanisms are substantially identical to one another, and the folding fingers of all coupling mechanisms are substantially identical to one another. The tips or coupling points of all folding fingers then move in sequence in a phase-shifted manner corresponding to their angular distance on the same path (coupling point path) and engage in sequence at substantially the same position in the packaging film.

[0046] Different forms of transmission devices can be used to cause the movement of the components of the above-mentioned coupling mechanism. In a first embodiment, a separate transmission device is provided for each crank element of each coupling mechanism. The transmission devices are each designed to control the rotational movement of the crank element, in particular to accelerate and / or brake the crank element in phase with a predetermined speed curve, and / or to move it at a constant speed.

[0047] This transmission variant is particularly suitable for coupling mechanisms formed by crank-rocker mechanisms, wherein the crank element is thus driven, while the rocker element is driven only indirectly via the connecting element by means of a displacement of the crank element, as explained above, for example, in conjunction with FIG 6. In contrast, if the coupling mechanism is formed by a parallel crank mechanism, as described above, for example, in conjunction with FIG 4, then typically only one of the two crank elements is driven, while the other crank element is driven only indirectly via an overdrive (e.g. a belt drive) and / or the connecting element is driven by means of a displacement of the first crank element.

[0048] In the mentioned embodiment, a separate transmission device is provided for each crank element of each connecting mechanism, and if the same number of folding fingers and connecting mechanisms (consisting of crank elements and / or rocker elements) are provided in the hem folding device, the transmission devices of the crank elements respectively assigned to the connecting mechanisms are preferably designed and synchronized with each other so that the crank elements rotate with a predetermined speed curve so that the folding fingers respectively assigned to the connecting mechanisms are successively engaged into the packaging film with a regular phase offset relative to each other corresponding to the number of connecting mechanisms.

[0049] If the hem folding device has, for example, two folding fingers, they are therefore engaged in the film with a phase offset of 180°. Specifically, in this case, two coupling mechanisms are provided, wherein one folding finger is attached to the connecting element of each coupling mechanism, so that when the crank elements of the coupling mechanisms rotate, the folding fingers respectively assigned to the two coupling mechanisms are successively engaged in the packaging film with a phase of 180° relative to each other. Correspondingly, it applies that if the hem folding device has three folding fingers, they are engaged in the film with a phase offset of 120°. If the hem folding device has more folding fingers, the value of the phase offset varies with the quotient of 360° divided by the number of folding fingers.

[0050] In a second alternative embodiment of the transmission, a single transmission may be provided which is configured to control the rotational movement of all crank elements of the coupling mechanism, in particular to accelerate and / or brake all crank elements synchronously with a predetermined identical speed profile and / or to move them at a constant speed.

[0051] This transmission variant is therefore particularly suitable when the coupling mechanism is formed by a crank-rocker mechanism, in which the crank element is thus driven, while the rocker element is not driven directly by the transmission. In contrast, if the coupling mechanism is formed by a parallel crank mechanism, then usually only one of the two crank elements is driven by the transmission, while the other crank element is driven only indirectly via an overdrive and / or the connecting element is driven by means of a displacement of the first crank element.

[0052] In the second embodiment mentioned, a single transmission device is provided, which controls all crank elements in unison or simultaneously, and further, if the same number of folding fingers and coupling mechanisms (consisting of crank elements and / or rocker elements) is provided in the hem folding device, the crank elements of the coupling mechanisms are preferably arranged at equal angular distances relative to each other. The crank elements are then rotated at a predetermined speed profile so that the folding fingers respectively assigned to the coupling mechanisms are successively engaged in the packaging film with a regular phase offset corresponding to the number of coupling mechanisms relative to each other.

[0053] Therefore, as described above, the following also applies here: if the hem folding device has, for example, two folding fingers, they engage in the film with a phase offset of 180°; if the hem folding device has three folding fingers, they engage in the film with a phase offset of 120°; etc.

[0054] The method of the above-mentioned second embodiment of the transmission device, in which a single transmission device, such as a servomotor, is provided, which drives, for example, two identical crank-rocker mechanisms coupled to each other, is advantageous in terms of process engineering design and construction as well as in terms of costs. Here, the cranks and the folding fingers assigned to them are phase-shifted by 180°. As mentioned above, during the return travel of the folding fingers to their starting position or initial position for the next folding operation, the actual movement (e.g., speed profile) is irrelevant for the entire process. It is only important that the folding fingers reach their starting position again in a timely manner (i.e., in a time-accurate and position-accurate manner) by means of the return stroke. Therefore, the servomotor can control the hem folding performed by the folding fingers of the second crank mechanism during the return stroke of the folding fingers of the first crank mechanism. In other words, both folding fingers move with the same speed profile executed by the servomotor, wherein this profile is only relevant to and coordinated with the hem folding process performed by one folding finger, and this profile is independent of the simultaneous return stroke of the other folding finger.

[0055] This embodiment, in which a single transmission drives two identical crank-rocker mechanisms coupled to one another, has the advantage over the other embodiments described above, in which each crank-rocker mechanism is driven by a separate transmission, in particular that only one drive motor takes up less space and that its spatial arrangement is simpler than that of a plurality of separate drive motors. In contrast, in the case of a plurality of separate drive motors, the advantage is that the individual crank mechanisms can be actuated individually and independently of one another, if necessary.

[0056] As already mentioned above, in the hem folding device, each of the at least two coupling mechanisms is designed and arranged so that the first coupling element (i.e. crank element), the second coupling element (i.e. crank element or rocker element) and the connecting element of the at least two coupling mechanisms and / or the folding fingers respectively assigned to the coupling mechanisms do not collide with each other during their movement. In particular, by a somewhat layered or laminar construction of the hem folding device, collisions between the folding fingers and / or other components of the hem folding device can be eliminated. In this context, the first coupling element, the second coupling element, the connecting element and the folding fingers respectively assigned to one of the at least two coupling mechanisms are arranged substantially in one plane or move in a plane arranged substantially parallel to the conveying plane of the tubular bag packaging machine. Such a plane differs from the corresponding plane of another of the at least two coupling mechanisms relative to the conveying plane of the tubular bag packaging machine.

[0057] If, for example, two coupling mechanisms are provided, the first plane in which the components of the first coupling mechanism move can be arranged parallel to the conveying plane of the tubular bag machine and, for example, substantially below the conveying plane, while the second plane in which the components of the second coupling mechanism move can be arranged parallel to the conveying plane of the tubular bag machine and, for example, substantially above the conveying plane. As explained above, it should be understood in this context that the actual area in which the coupling mechanism moves is located laterally outside the conveying path of the product and the film tube, i.e., outside the packaging unit to be formed. In addition, it should be understood that the folding fingers of at least two coupling mechanisms must be configured and arranged so that they are finally joined with their tips each being substantially at the same position in the conveying path entering the packaging film from the outside to form the packaging film hem.

[0058] In the above case, in which the hem folding device has two or more coupling mechanisms, each configured as a crank-rocker mechanism, the crank elements of the coupling mechanisms can be connected to one another and / or configured such that they form a crankshaft with a crank. If two crank-rocker coupling mechanisms are provided and they interact, each forming a four-component mechanism, the two four-component mechanisms can therefore be extended in construction by a common crankshaft with a crank to form a six-component mechanism.

[0059] For all embodiments of the invention described above, a folding device is therefore provided, which is configured and operated so that before sealing the transverse sealing seam and separating the film tube into individual packaging units, the folding device folds the packaging film in the region of the two side faces of the packaging unit to be formed so that the length of the transverse sealing seam after its sealing corresponds essentially to the width of the product packaged in the packaging unit, which width extends transversely to the conveying direction of the tubular bag packaging machine. In this context, after sealing the transverse sealing seam and after separating it into the rear transverse sealing seam of the first preceding packaging unit and the front transverse sealing seam of the second succeeding packaging unit, a packaging film hem is formed in the region of each side end of each (partial) transverse sealing seam thus formed or in the transition region of the respective side end of the (partial) transverse sealing seam to the respective side face of the finished individual packaging unit, the packaging film hem being configured so that the packaging film is folded in the region of each side end of each transverse sealing seam so that it is superimposed on each other in four layers.

[0060] As shown above, a folding device of the present invention is provided, which includes at least one folding finger and at least two cooperating coupling mechanisms, wherein each coupling mechanism includes a movable first coupling element (crank element), a movable second coupling element (crank element or rocker element) and a connecting element connecting them. In this article, at least one folding finger is attached to one of the connecting elements of at least two coupling mechanisms. Therefore, in principle, the folding device according to the present invention can also be operated with only a single folding finger and two or more coupling mechanisms without removing the components of the gear mechanism or coupling mechanism. The additional gear mechanism (e.g., crank element, connecting element, rocker element, crankshaft with crank) of the coupling mechanism without folding fingers is advantageous from a dynamic point of view, because mass compensation is thereby generated, that is, the process-induced vibration caused by the movement of the entire hem folder is, for example, significantly reduced. Therefore, mass force compensation can be achieved by additional gear mechanism elements (which are not combined with folding fingers) and thus reducing the vibration transmitted to the frame or substructure of the tubular bag machine or to the entire tubular bag machine.

[0061] The invention also provides a method for folding packaging films in a tubular bag packaging machine in the region of a transverse sealing seam to form a packaging unit, wherein the method is characterized in that it is implemented using a folding device according to the invention as described above.

[0062] The present invention also provides a tubular bag packaging machine for forming a packaging unit containing a product from a packaging film, wherein the machine comprises the following features: a transverse sealing device for forming a transverse sealing seam extending transversely to the conveying direction of the tubular bag packaging machine in a film tube or on a packaging unit; and a folding device according to the present invention as described above, which is used to fold the packaging film in the area where the transverse sealing seam is to be formed. In this context, the folding device is arranged upstream of the transverse sealing device along the conveying direction of the tubular bag packaging machine, in particular so that the folding device and the transverse sealing device or their components do not collide with each other during their respective movements. The transverse sealing device generally also has a cutter device, with which the individual packaging units are successively separated from the film tube during the formation of the corresponding transverse sealing seams. In this context, with the help of the cutter device, the transverse sealing seams initially formed in the continuous film tube are each divided into two partial transverse sealing seams, specifically the rear transverse sealing seam of the first preceding packaging unit and the front transverse sealing seam of the second succeeding packaging unit.

[0063] The present invention finally provides a packaging unit formed by a packaging film and containing a product, wherein the packaging unit is formed by means of a folding device according to the present invention and / or a tubular bag packaging machine according to the present invention and / or by using a method according to the present invention, which are described above respectively. In this context, the finished packaging unit according to the present invention has a transverse sealing seam extending transversely to the conveying direction at its front and rear ends along the conveying direction of the tubular bag packaging machine, wherein the length of each transverse sealing seam substantially corresponds to the width of the product packaged in the packaging unit extending transversely to the conveying direction, and wherein a packaging film hem is formed in the region of each side end of each transverse sealing seam or in the transition region of the corresponding side end of the transverse sealing seam to the corresponding side of the packaging unit, the packaging film hem being configured so that the packaging film is folded in the region of each side end of each transverse sealing seam so that it overlaps one another in four layers. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Further details and advantages of the invention will emerge from the following more detailed description of exemplary embodiments of the invention based on the drawings.

[0065] Fig. 1a shows a prior art packaging unit in plan view.

[0066] Figure 1b The packaging unit in Fig. 1a is shown in a cross-sectional view taken along line AA in Fig. 1a.

[0067] Figure 2a The packaging unit according to the invention is shown in plan view.

[0068] Figure 2b Along the Figure 2a The cross-sectional view taken along line BB in FIG. Figure 2a The packaging unit in.

[0069] Figure 3 Shown in perspective Figure 2a and Figure 2b The packaging unit in.

[0070] FIG. 4 shows a parallel crank hem folding mechanism in the prior art.

[0071] Figure 5a to Figure 5c The movement sequence of the parallel crank hem folding mechanism in FIG. 4 is shown.

[0072] FIG. 6 shows a crank rocker hem folding mechanism in the prior art.

[0073] Figure 7 A combination of a parallel crank hem folding mechanism and a crank rocker hem folding mechanism according to the present invention is shown.

[0074] Figure 8An embodiment according to the invention is shown with a combination of two crank rocker hem folding mechanisms which are actuated separately.

[0075] Fig. 9 An embodiment of a combination of two crank-rocker hem-folding mechanisms with coupled actuation according to the invention is shown.

[0076] Fig.10 Shows Fig. 9 An embodiment of a combination of two crank-rocker hem folding mechanisms with coupling actuation.

[0077] Figures 11a to 11f Shows Figure 8 or Fig. 9 The moving sequence of the combined crank-rocker hem folding mechanism. DETAILED DESCRIPTION

[0078] The subject matter shown in Figures 1a to 6 has already been explained at the outset in connection with the discussion of the prior art. Insofar as features of the invention discussed below correspond to features of the subject matter shown in Figures 1a to 6, reference is made to these preceding figures and the associated description above.

[0079] As already mentioned above, the accompanying drawings (particularly FIGS. 4 to Fig. 9 ) are merely schematic diagrams. The shown movement, drive or passage directions of the components of the coupling mechanism are to be understood only as examples and are not decisive or mandatory. The actual geometry of the coupling point path and its passage direction depend on the respectively selected gear size. The schematically drawn coupling point path of the crank-rocker mechanism is to be understood only from a qualitative point of view and does not necessarily have the form shown in practice.

[0080] Figure 7 The hem folding device 100 is shown, which is formed by a combination of a parallel crank hem folding mechanism 110 and a crank rocker hem folding mechanism 120. The parallel crank mechanism 110 shown here basically corresponds to the hem folding device 100 from FIG. Figure 5a to Figure 5c The crank-rocker mechanism 120 shown here corresponds essentially to the crank-rocker mechanism 20 known from FIG. 6 . Figure 7 The folding device 100 comprises two hem folding mechanisms 110, 120, which are different and substantially separated from each other, and are separately actuated via a dedicated transmission device 116, 126. The two hem folding mechanisms 110, 120 have different connection point paths 117, 127, specifically, a substantially circular path 117 in the case of the parallel crank mechanism 110, and a substantially non-circular path 127 in the case of the crank rocker mechanism 120, as described above in conjunction with Figures 4 to 6.

[0081] according to Figure 7The crank elements 111, 112 of the parallel crank mechanism 110 can be rotated, for example, clockwise or counterclockwise, depending on the desired conveying direction F of the product in the parallel crank mechanism 110. The crank element 121 of the crank-rocker mechanism 120 shown rotates, for example (but not necessarily) clockwise according to the indicated arrow direction. However, a counterclockwise rotation direction is also conceivable. Since it is connected to the crank element 121 via the connecting element 123, the rocker element 122 of the crank-rocker mechanism 120 oscillates back and forth according to the indicated double arrow direction. Therefore, the tip 115 of the folding finger 114 of the parallel crank mechanism 110 and the tip 125 of the folding finger 124 of the crank-rocker mechanism 120 move on their respective connection point paths 117, 127. It goes without saying that it is also conceivable to appropriately reverse or change the mentioned movement direction. As already mentioned above, it should be noted that the illustration of the crank mechanism in the figure should only be understood in a schematic, exemplary and purely qualitative manner. The associated connection point paths are therefore likewise only schematically drawn by way of example. In the present case, therefore, to the extent that a specific movement direction or rotation direction of a component is mentioned, this should only be understood by way of example and not by way of conclusion.

[0082] Figure 7 Two hem folding mechanisms 110, 120 and therefore their two connection point paths 117, 127 which are spatially separated from each other are shown. Thus, the tips 115, 125 of the two folding fingers 114, 124 engage in the packaging film at different positions in the conveying path of the packaging machine in order to form the packaging film hem. However, it is also conceivable to appropriately superimpose the two hem folding mechanisms 110, 120 and therefore their connection point paths 117, 127, so that the two tips 115, 125 engage in the packaging film at essentially the same position in the conveying path. In this case, the two hem folding mechanisms 110, 120 can be driven and controlled so that the two tips 115, 125 engage in the film alternately in a phase-shifted manner.

[0083] Figure 8 A hem folding device 200 is shown which is formed by the combination of two identical crank-rocker hem folding mechanisms 220 and 230. The two crank-rocker mechanisms 220, 230 themselves each correspond substantially to the crank-rocker mechanism 20 known from FIG.

[0084] The first crank-rocker hem folding mechanism 220 thus consists of a first crank element 221 rotatable by 360° and a rotatable first rocker element 222 oscillating back and forth between two end positions. A first coupling element or connecting element 223 connects the crank element 221 to the rocker element 222. A folding finger 224 with a tip 225 is attached to the coupling element 223. The crank element 221 is driven by a suitable first transmission 226 and rotates therein, in particular, by 360°. Due to the coupling via the coupling element 223, the rocker element 222 thus performs an oscillating movement within a predetermined angular range (see the indicated double arrow). As a result, the tip 225 of the folding finger 224 moves on the coupling point path 227. At Figure 8 In the embodiment shown, the crank element 221 rotates clockwise, for example (but not necessarily) according to the indicated arrow direction. However, a counterclockwise rotation direction is also conceivable. Thus, an oscillating movement of the rocker element 222 is achieved. Due to this movement system, the tip 225 of the folding finger 224 moves on the schematically shown connection point path 227. During this movement, in order to form the packaging film hem Z, the tip 225 alternately engages in the packaging film or retracts out of engagement with the packaging film. In principle, the passing or movement direction of the mechanism or its components here also depends on the actual size of the mechanism.

[0085] The second crank rocker hem folding mechanism 230 of the hem folding device 200 (in Figure 8 In principle, the first crank rocker hem folding mechanism 220 (shown in dashed lines in FIG. Figure 8 Thus, the second crank-rocker mechanism 230 consists of a rotatable second crank element 231 and a rotatable second rocker element 232, which are connected to each other via a second coupling element or connecting element 233. A folding finger 234 with a tip 235 is attached to the coupling element 233. The second crank element 231 is driven by a suitable second transmission 236 and rotates therein, in particular, by 360°.

[0086] Due to the coupling via the coupling element 233, the second rocker element 232 thus performs an oscillating movement within a predetermined angular range (see the indicated double arrow). As a result, the tip 235 of the folding finger 234 moves on the coupling point path 237. Figure 8In the embodiment shown, the second crank element 231 (similar to the first crank element 221) also rotates clockwise, for example (but not necessarily) according to the indicated arrow direction, and thus realizes the oscillating movement of the second rocker element 232 and the movement of the tip 235 of the folding finger 234 on the connection point path 237. During this movement, the tip 235 is alternately engaged in the packaging film or retracted out of engagement with the packaging film in order to form the packaging film hem Z. The relationship shown here should also be understood only in a schematic, exemplary manner, and the passing or movement direction of the mechanism or its components here also depends on the actual size of the mechanism.

[0087] like Figure 8 As shown, the connection point paths 227, 237 of the two crank rocker hem folding mechanisms 220, 230 are identical and completely consistent. For this reason, it is particularly required that the corresponding components of the two folding mechanisms 220, 230 are configured to be substantially identical, especially in terms of their size and operating mode. In addition, the two crank elements 221, 231 must in principle be mounted on the same and co-located bearings 221a, 231a. Therefore, the two rocker elements 222, 232 must in principle be mounted on the same and co-located bearings 222a, 232a.

[0088] Figure 8 The two crank rocker hem folding mechanisms 220 and 230 are driven and actuated individually, that is, they are driven and actuated individually and independently of each other in principle. For this purpose, a separate transmission device 226, 236, such as a servo motor, is provided. However, the two transmission devices 226, 236 are preferably controlled so that the tips 225, 235 of the two folding fingers 224, 234 move on the connection point paths 227, 237, so that the tips 225, 235 are finally engaged in the packaging film at substantially the same position in the conveying path with a phase offset of 180 °. For this reason, it is not absolutely required that the two tips 225, 235 move continuously at the same and / or constant speed and / or at the same angular distance from each other on the connection point paths 227, 237. The only important thing is that the tips 225, 235 are each used alternately at substantially the same position in a time-accurate and position-accurate manner to be engaged in the packaging film.

[0089] It goes without saying that the two independent transmissions 226, 236 can also be flexibly controlled individually as required, so that the tips 225, 235 move on the coupling point paths 227, 237 at alternating individual speeds and / or not with a phase shift of 180° but with another asymmetrical or irregular phase shift or also with a variable phase shift. This may be necessary, for example, if the successive products in the conveying path of the packaging machine have different forms and / or sizes.

[0090] Fig. 9A hem folding device 200 is shown, which corresponds substantially to Figure 8 The hem folding device 200 shown is formed by a combination of two identical crank rocker hem folding mechanisms 220 and 230. For the individual components of the two hem folding mechanisms 220 and 230 and their basic functions, please refer to Figure 8 and the related description above.

[0091] However, Fig. 9 Examples and Figure 8 The embodiment of the present invention differs in that now only a single transmission device 246, for example a servomotor, is provided, which drives and actuates the first crank element 221 and the second crank element 231 together. To this end, the first crank element 221 and the second crank element 231 are coupled to each other, preferably fixedly connected to each other. Fig. 9 As shown, the two crank elements 221 and 231 are preferably connected to each other in a line, i.e. at an angle of 180° relative to their longitudinal extension. Thus, the tips 225, 235 of the two folding fingers 224, 234 move continuously on the same connection point path 227, 237 at the same speed and at the same fixed angular distance from each other, due to the drive of the common transmission 246. Fig. 9 In the case of the two crank elements 221, 231 shown in a linear arrangement at an angle of 180° relative to each other, the tips 225, 235 therefore move on the connection point paths 227, 237 with a phase offset of 180° and thus each engages in the packaging film alternately at essentially the same position in the conveying path in a time- and position-accurate manner.

[0092] In this embodiment of the coupled actuation of the two hem folding mechanisms 220 and 230, the tips 225, 235 are therefore not able to move on the coupling point paths 227, 237 at alternating and / or individual speeds and / or at alternating phase offsets relative to each other. However, it is conceivable that the two crank elements 221 and 231 are connected to each other in a non-linear manner, i.e., at an angle other than 180° relative to their longitudinal extension. The two tips 225, 235 then move on the coupling point paths 227, 237 at unequal, asymmetrical but fixed phase offsets that alternately correspond to the larger and smaller angles at which the two crank elements 221 and 231 are connected to each other.

[0093] Fig.10 Shows Fig. 9 An exemplary construction embodiment of a combination of two crank-rocker hem folding mechanisms actuated by coupling. Fig. 9 The two four-component hem folding mechanisms 220 , 230 are here structurally expanded by a common crankshaft 341 with a crank to form a six-component mechanism of the hem folding device 300 .

[0094] The crankshaft 341 with crank includes a first crank element 321 of the first crank rocker hem folding mechanism 320 and a second crank element 331 of the second crank rocker hem folding mechanism 330. Therefore, the first crank element 321 and the second crank element 331 are linearly fixedly connected to each other at an angle of 180°. The first crank rocker hem folding mechanism 320 also includes a first coupling element or connecting element 323 and a first rocker element 322. The second crank rocker hem folding mechanism 330 also includes a second coupling element or connecting element 333 and a second rocker element 332. A first folding finger 324 having a tip 325 is attached to the first coupling element 323. A second folding finger 334 having a tip 335 is attached to the second coupling element 333.

[0095] The crankshaft 341 with crank is rotatably mounted on the bearing 341a and driven and actuated by a transmission device 346 (e.g., a servo motor), in particular, rotates 360° around the bearing 341a. Due to the rotation of the crankshaft 341 and the connection via the coupling elements 323, 333, the first rocker element 322 and the second rocker element 332 mounted on the common bearings 322a, 332a move back and forth in an oscillating manner. Due to the movement of the two coupling elements 323, 333, the two folding fingers 324, 334 move so that their tips 325, 335 eventually engage in the packaging film at substantially the same position in the conveying path of the packaging machine alternately with a phase offset of 180° so as to form a packaging film hem each therein.

[0096] from Fig.10 As can be seen in the figure, the two crank rocker hem folding mechanisms 320, 330 are arranged so that their respective components are essentially in different planes or layers or are arranged in layers and move essentially in these different planes. As a result, the components of the two crank rocker hem folding mechanisms 320, 330 are prevented from colliding during their movement. Therein, the two folding fingers 324, 334 and / or their tips 325, 335 are configured, for example, in a curved manner, so that the tips 325, 335 alternately engage in the packaging film in essentially the same position and / or plane in the conveying path of the packaging machine.

[0097] Figures 11a to 11f The combined crank rocker hem folding mechanism 220, 230 is shown. Figure 8 or Fig. 9 An exemplary movement sequence of the hem folding device 200 is shown. Figures 11a to 11f The reference numerals used in Figure 8 or Fig. 9 The reference numerals used in the drawings are the same and therefore refer to the same components. The first crank rocker hem folding mechanism 220 is Figures 11a to 11f2 and 3. The second crank rocker hem folding mechanism 230 is shown in solid lines in the figures, while the second crank rocker hem folding mechanism 230 is shown in dotted lines in these figures.

[0098] exist Figures 11a to 11f In the embodiment of the present invention, products P1, P2, P3, etc. are conveyed from right to left along the conveying direction F. The first folding finger 224 and the second folding finger 234 are in principle moved cyclically here, so that one folding finger 224, 234 from the lower right respectively engages with its respective tip 225, 235 upwards in the gap existing between two consecutive products P1, P2, P3, moves further along the conveying direction F with the product flow, and then exits from the product flow to the lower left, in order to then return to its starting position to the right again for the next cycle. Therefore, the two folding fingers 224, 234 are preferably moved here, so that they engage alternately between two consecutive products with a phase offset of 180° relative to each other into the packaging film.

[0099] The first crank element 221 is connected here in a linear manner (i.e. at an angle of 180°) to the second crank element 231. The two crank elements 221, 231 rotate counterclockwise around the common bearing point 221a, 231a by means of one or more suitable transmission devices. As a result, the first rocker element 222 and the second rocker element 232 mounted on the common bearing point 222a, 232a oscillate back and forth. Fig.11a It can be seen that the first folding finger 224 engages here from below into the gap between the products P1 and P2 .

[0100] By continuing to rotate the two crank elements 221, 231, the first folding finger 225 reaches its maximum engagement depth or penetration depth in the gap between the products P1 and P2 (see Fig.11b ). When the two crank elements 221, 231 are further rotated counterclockwise, the first folding finger 224 withdraws downward from the conveying path, while the second folding finger 234 from the lower right approaches the conveying path (see Fig.11c ) in order to join into the gap between product P2 and subsequent product P3 (see Fig.11d ). This position of the second folding finger 234 and of the components of the second hem folding mechanism 230 assigned thereto corresponds substantially to Fig.11a 2 and 3. The positions of the first folding finger 224 and the components of the first hem folding mechanism 220 assigned thereto are shown in FIG.

[0101] By continuing the rotation of the two crank elements 221, 231, the second folding finger 234 reaches its maximum engagement depth in the gap between the products P2 and P3 (see Fig.11e ). This position of the second folding finger 234 and of the components of the second hem folding mechanism 230 assigned thereto corresponds substantially to Fig.11b2 and 3. The positions of the first folding finger 224 and the components of the first hem folding mechanism 220 assigned thereto are shown in FIG.

[0102] When the two crank elements 221, 231 rotate further counterclockwise, the second folding finger 234 withdraws downward from the product flow, while the first folding finger 224 from the lower right approaches the conveying path again (see Fig.11f ) so as to engage in the gap between product P3 and the subsequent product. Fig.11f The position of the second folding finger 234 and the components of the second hem folding mechanism 230 assigned thereto substantially corresponds to Fig.11c 2 and 3. The positions of the first folding finger 224 and the components of the first hem folding mechanism 220 assigned thereto are shown in FIG.

[0103] Figures 8 to 11f The hem folding device shown in always comprises, for example, two coupling mechanisms and two folding fingers, which are preferably moved relative to each other with a phase offset of 180° and alternately engage in the packaging film to form the hem. However, as explained above, in principle more than two interacting coupling mechanisms can also be provided. In principle, there can also be only one folding finger or more than two folding fingers. However, more than two coupling mechanisms and more than two folding fingers mean correspondingly higher costs in terms of construction and control technology compared to the variant with two coupling mechanisms and two folding fingers.

Claims

1. A folding device for folding a packaging film in a tubular bag packaging machine in the region of a transverse sealing seam (Q) to be formed of a packaging unit (V) to be formed, wherein the transverse sealing seam (Q) extends substantially in a conveying plane and perpendicularly to the conveying direction (F) of the tubular bag packaging machine, wherein the packaging unit (V) to be formed has two side surfaces (S) extending substantially along the conveying direction (F) and perpendicular to the conveying plane of the tubular bag packaging machine, The folding device comprises two hem folding devices (100; 200; 300), wherein in the region of the transverse sealing seam (Q) to be formed, substantially on the outside of each side surface (S) of the packaging unit (V) to be formed, a respective hem folding device (100; 200; 300) is arranged, It is characterized in that Each of the two hem folding devices (100; 200; 300) comprises the following features: - at least one folding finger (114, 124; 224, 234; 324, 334), which is configured and movable so that it engages laterally from the outside into the side surface (S) of the packaging unit (V) to be formed in the region of the transverse sealing seam (Q) to be formed and presses the side surface (S) inwardly, at least partially and substantially in the direction of the transverse sealing seam (Q) to be formed, perpendicularly to the conveying direction (F); and - at least two coupling mechanisms (110, 120; 220, 230; 320, 330), wherein each coupling mechanism (110, 120; 220, 230; 320, 330) comprises the following features: . A movable first coupling element (111, 121; 221, 231; 321, 331), . A movable second coupling element (112, 122; 222, 232; 322, 332), a connecting element (113, 123; 223, 233; 323, 333) configured such that it connects the first coupling element (111, 121; 221, 231; 321, 331) and the second coupling element (112, 122; 222, 232; 322, 332) to each other; - wherein one folding finger (114, 124; 224, 234; 324, 334) is attached to the connecting elements (113, 123; 223, 330) of the at least two coupling mechanisms (110, 120; 220, 230; 320, 330) 233; 323, 333).

2. A folding device according to claim 1, wherein each of the two hem folding devices (100; 200; 300) has two folding fingers (114, 124; 224, 234; 324, 334) and two connecting mechanisms (110, 120; 220, 230; 320, 330), wherein each one folding finger (114, 124; 224, 234; 324, 334) is attached to a connecting element (113, 123; 223, 233; 323, 333) of each connecting mechanism (110, 120; 220, 230; 320, 330) of each hem folding device (100; 200; 300).

3. The folding device according to claim 1 or 2, wherein at least one of the at least two coupling mechanisms (110, 120) is configured so that the first coupling element (111) and the second coupling element (112) are each a crank element, and the crank element is configured so that it can rotate 360° around an axis, The axes of the first crank element and the second crank element (111, 112) are substantially parallel to each other and extend perpendicularly to the conveying plane and perpendicularly to the conveying direction (F) of the tubular bag packaging machine.

4. The folding device according to claim 1 , wherein at least one of the at least two coupling mechanisms ( 110 , 120 , 220 , 230 , 320 , 330 ) is configured so that the first coupling element ( 121 , 221 , 231 , 321 , 331 ) is a crank element, the crank element being configured so that it can rotate 360° around an axis, and The second coupling element (122; 222, 232; 322, 332) is a rocker element configured such that it can rotate about an axis and oscillate back and forth between two end positions, The axis of the crank element (121; 221, 231; 321, 331) and the axis of the rocker element (122; 222, 232; 322, 332) are substantially parallel to each other and extend perpendicularly to the conveying plane and perpendicularly to the conveying direction (F) of the tubular bag packaging machine.

5. The folding device according to claim 4, wherein each of the two hem folding devices (200; 300) has two coupling mechanisms (220, 230; 320, 330), wherein each of the two coupling mechanisms (220, 230; 320, 330) is configured such that The first coupling element is a crank element (221, 231; 321, 331) configured so that it can rotate 360° around an axis, and The second coupling element is a rocker element (222, 232; 322, 332) configured such that it can rotate about an axis and oscillate back and forth between two end positions, The axis of the crank element (221, 231; 321, 331) and the axis of the rocker element (222, 232; 322, 332) are substantially parallel to each other and extend perpendicularly to the conveying plane and perpendicularly to the conveying direction (F) of the tubular bag packaging machine.

6. The folding device according to claim 5, - wherein the crank element (221; 321) of the first coupling mechanism (220; 320) has substantially the same dimensions as the crank element (231; 331) of the second coupling mechanism (230; 330), in particular of the same length, and wherein the axis of rotation of the crank element (221; 321) of the first coupling mechanism (220; 320) is identical to the axis of rotation of the crank element (231; 331) of the second coupling mechanism (230; 330); - wherein the rocker element (222; 322) of the first coupling mechanism (220; 320) has substantially the same dimensions as the rocker element (232; 332) of the second coupling mechanism (230; 330), in particular the same length, and wherein the axis of rotation of the rocker element (222; 322) of the first coupling mechanism (220; 320) is the same as the axis of rotation of the rocker element (232; 332) of the second coupling mechanism (230; 330); and - wherein the folding finger (224; 324) of the first coupling mechanism (220; 320) has substantially the same size, in particular the same length, as the folding finger (234; 334) of the second coupling mechanism (230; 330).

7. A folding device according to any one of claims 3 to 6, wherein it respectively has a transmission device (226, 236) for each crank element (221, 231), wherein the transmission device (226, 236) is configured to control the rotational movement of the crank element (221, 231), in particular to control the rotational movement in phase with a predetermined speed curve so as to accelerate and / or brake the crank element (221, 231) and / or move it at a constant speed.

8. The folding device according to claim 7, wherein the hem folding device (200) comprises the same number of folding fingers (224, 234) and coupling mechanisms (220, 230), and The transmission devices (226, 236) of the crank elements (221, 231) respectively assigned to the connecting mechanisms (220, 230) are configured and synchronized with each other so that the crank elements (221, 231) rotate at the predetermined speed curve, so that the folding fingers (224, 234) respectively assigned to the connecting mechanisms (220, 230) are each successively engaged in the packaging film in the area of ​​the transverse sealing seam (Q) formed by the continuous packaging units (V) with respect to each other at a regular phase offset corresponding to the number of the connecting mechanisms (220, 230).

9. A folding device according to any one of claims 3 to 6, wherein it has a transmission device (246; 346), which is configured to control the rotational movement of all crank elements (221, 231; 321, 331), in particular to control the rotational movement in phase with a predetermined identical speed curve so that all crank elements (221, 231; 321, 331) are accelerated and / or braked simultaneously and / or moved at a constant speed.

10. The folding device according to claim 9, wherein the hem folding device (200; 300) comprises the same number of folding fingers (224, 234; 324, 334) and coupling mechanisms (220, 230; 320, 330), and The crank elements (221, 231; 321, 331) of the connecting mechanism (220, 230; 320, 330) are arranged at equal angular distances relative to each other, so that the crank elements (221, 231; 321, 331) rotate at the predetermined speed curve, so that the folding fingers (224, 234; 324; 334) respectively assigned to the connecting mechanism (220, 230; 320; 330) are each successively engaged in the packaging film in the area of ​​the transverse sealing seam (Q) formed by the continuous packaging unit (V) with respect to each other at a regular phase offset corresponding to the number of the connecting mechanisms (220, 230; 320; 330).

11. A folding device according to claim 8 or 10, wherein the folding device comprises two connecting mechanisms (220, 230; 320, 330), wherein each folding finger (224, 234; 324, 334) is attached to the connecting element (223, 233; 323, 333) of each connecting mechanism (220, 230; 320, 330), so that when the crank element (221, 231; 321, 331) of the connecting mechanism (220, 230; 320, 330) rotates, the folding fingers (224, 234; 324, 334) respectively assigned to the two connecting mechanisms (220, 230; 320, 330) are successively engaged in the packaging film with a phase offset of 180° relative to each other.

12. Folding device according to any one of claims 9 to 11, wherein the crank elements (321, 331) of the coupling mechanism (320, 330) are connected to each other so that they form a cranked crankshaft (341).

13. A folding device according to any one of the preceding claims, wherein each of the at least two connecting mechanisms (110, 120; 220, 230; 320, 330) is configured and arranged so that the first connecting element (111, 121; 221, 231; 321, 331), the second connecting element (112, 122; 222, 232; 322, 332) and the connecting element (113, 123; 223, 233; 323, 333) of the connecting mechanism (110, 120; 220, 230; 320, 330) and / or the folding fingers (114, 124; 224, 234; 324, 334) respectively assigned to the connecting mechanism (110, 120; 220, 230; 320, 330) do not collide with each other during their movement.

14. The folding device according to claim 13, wherein the first coupling element (111, 121; 221, 231; 321, 331), the second coupling element (112, 122; 222, 232; 322, 332), the connecting element (113, 123; 223, 233; 323, 333) and the folding fingers (114, 124; 224, 234; 324, 334) respectively assigned to one of the at least two coupling mechanisms (110, 120; 220, 230; 320, 330) are substantially arranged in a plane, which is arranged substantially parallel to the conveying plane of the tubular bag packaging machine and is different from the corresponding plane of the other coupling mechanism of the at least two coupling mechanisms (110, 120; 220, 230; 320, 330) relative to the conveying plane of the tubular bag packaging machine.

15. A folding device according to any one of the preceding claims, wherein the folding device is configured so that, before sealing the transverse sealing seam (Q), the packaging film is folded in the region of the two side faces (S) of the packaging unit (V) to be formed, so that the length (LQ) of the transverse sealing seam (Q) after sealing substantially corresponds to the width (BV) of the product (P) packaged in the packaging unit (V), the width extending transversely to the conveying direction (F) of the tubular bag packaging machine, And after sealing the transverse sealing seam (Q), a packaging film hem (Z) is formed in the area of ​​each side end of the transverse sealing seam (Q) or in the transition area from the corresponding side end of the transverse sealing seam (Q) to the corresponding side surface (S) of the packaging unit (V), and the packaging film hem is configured so that the packaging film is folded in the area of ​​each side end of the transverse sealing seam (Q) so that it overlaps each other in four layers.

16. A method for folding a packaging film in a tubular bag packaging machine in the region of a transverse sealing seam (Q) to be formed into a packaging unit (V), characterized in that The method is performed using a folding device according to any one of the preceding claims.

17. A tubular bag packaging machine for forming a packaging unit (V) containing a product (P) from a packaging film, characterized by the following features: - transverse sealing means for forming, on the packaging unit (V), a transverse sealing seam (Q) extending transversely to the conveying direction (F) of the tubular bag packaging machine; as well as - a folding device according to any one of claims 1 to 15, for folding the packaging film in the region where a transverse sealing seam (Q) is to be formed; - wherein the folding device is arranged upstream of the transverse sealing device in the conveying direction (F) of the tubular bag packaging machine.

18. A packaging unit (V) formed by a packaging film and containing a product (P), characterized in that The packaging unit (V) is formed by means of a folding device according to any one of claims 1 to 15 and / or a tubular bag packaging machine according to claim 17 and / or a method according to claim 16, The finished product packaging unit (V) has a transverse sealing seam (Q) at its front end and rear end in the conveying direction (F) of the tubular bag packaging machine, and the transverse sealing seam extends transversely to the conveying direction (F) of the tubular bag packaging machine. wherein the length (LQ) of each transverse sealing seam (Q) substantially corresponds to the width (BV) of the product (P) packaged in the packaging unit (V), the width (BV) extending transversely to the conveying direction (F) of the tubular bag packaging machine, and A packaging film hem (Z) is formed in the region of each side end of each transverse sealing seam (Q) or in the transition region from the corresponding side end of the transverse sealing seam (Q) to the corresponding side face (S) of the packaging unit (V), and the packaging film hem is configured so that the packaging film is folded in the region of each side end of each transverse sealing seam (Q) so that it is overlapped with each other in four layers.

Images