Device and method for forming a packaging film gusset in a 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) which is formed in a tubular-bag packaging machine. The folding device has two gusset folding apparatuses (100; 200; 300), wherein in each case one gusset folding apparatus (100; 200; 300) is arranged outside a side face (S) of the packaging unit (V) to be formed in the region of the transverse sealing seam (Q) to be formed. Each of the two gusset folding apparatuses (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, engages laterally from the outside into the side face (S) of the packaging unit (V) to be formed, and presses the side face (S) inwards perpendicularly to the feed direction (F) at least partially in the direction of the transverse sealing seam (Q) to be formed, in order to thus form a packaging film gusset (Z); and at least two coupling mechanisms (110, 120; 220, 230; 320, 330), wherein each coupling mechanism (110, 120; 220, 230; 320, 330) has a movable first coupling element, in particular a crank element (111, 121; 221, 231; 321, 331), a movable second coupling element, in particular a swing element (112, 122; 222, 232; 322, 332), and a connection element (113, 123; 223, 233; 323, 333) which connects the first and the second coupling element to one another. In each case, one folding finger (114, 124; 224, 234; 324, 334) is attached to one of the connection elements (113, 123; 223, 233; 323, 333) of the at least two coupling mechanisms (110, 120; 220, 230; 320, 330). The invention also relates to a tubular-bag packaging machine comprising a folding device according to the invention, and to a packaging unit which is formed by means of such a folding device and / or by means of such a tubular-bag packaging machine and / or using a method according to the invention.

Description

[0001] Device and method for forming a packaging film gusset in a tubular bag packaging

[0002] 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 also 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 using a method according to the invention.

[0003] The invention fundamentally relates to the packaging of products in a packaging film using a flow-wrap packaging machine, in particular a horizontal flow-wrap packaging machine. Here, pieced products or unit loads are inserted into a film tube, which is then divided into individual packaging units and sealed. Within the scope of the invention, in principle, all conceivable packaging materials can be used as packaging film, including, for example, plastic films, but also paper packaging. In such a flow-wrap packaging machine, the packaging film is fed as an endless belt and wrapped or folded and sealed around the product to be packaged. The subsequently separated individual packaging units are then removed.This method enables a fast and continuous process in which only a single packaging material (packaging film) is required and in which the resulting packaging units are generally more or less tightly sealed, preferably hermetically sealed depending on the application. Hermetic sealing can be achieved particularly with so-called heat-sealing machines. Such flow-wrap packaging machines are used, for example, in the packaging of confectionery, such as chocolate bars, chocolate bars, muesli bars, and the like, which typically have a rectangular or cuboid shape. In addition to such products from the confectionery industry, other products, such as industrial or technical products, are also conceivable.

[0004] Using such flow-wrapping machines, a longitudinal seal is generally first created. This seal runs in the conveying direction of the machine and is used to connect, in particular seal, the two lateral edges of the fed film tube wrapped around the product. The individual products are thus successively inserted into this film tube and are then arranged in the film tube at regular intervals from one another in the conveying direction. Using suitable transverse sealing devices or a transverse sealing station, a transverse seal is then formed in the film tube between each two consecutive products, running transversely to the conveying direction of the machine. The transverse sealing station typically has a knife device, by means of which the individual packaging units are separated from one another along the transverse seal.Here, the transverse seal is divided into two parallel transverse seals, namely a rear transverse seal of a first, leading packaging unit (as seen in the conveying direction) and a front transverse seal of a subsequent, second packaging unit (as seen in the conveying direction). By means of these closed transverse seals and the longitudinal seal, the respective packaging unit with the product contained therein is then completely formed and, in particular, tightly sealed.

[0005] Such a packaging unit V is shown in a plan view in Fig. 1 a. In this packaging unit V, the length LQ of the transverse sealing seam Q, i.e. the extension of the transverse sealing seam Q transversely to the conveying direction F, is typically greater than the width BV of the actual packaging unit V, i.e. the extension of the packaging unit V transversely to the conveying direction. In this case, the width BV of the packaging unit V essentially corresponds to the actual width of the packaged product, since the packaging film is usually wrapped tightly around the product. In particular, the length LQ of the transverse sealing seam Q here typically corresponds to the sum of the width BV of the product or the packaging unit V and the height of the product or the packaging unit V, whereby the height of the product extends perpendicular to the conveying plane.This length LQ of the transverse sealing seam Q results from the fact that when the film is folded around the product and when the transverse sealing seam Q is formed, excess film material in the area of ​​the two lateral ends of the transverse sealing seam Q or in the area of ​​the transition from the respective lateral end of the transverse sealing seam Q to the respective side surface S of the packaging unit V escapes laterally or outwards and then protrudes laterally (cf. Fig. 1 a).

[0006] Fig. 1 b shows the packaging unit V in a schematic sectional view along the line AA from Fig. 1 a. The section AA therefore extends along the transverse sealing seam Q. In Fig. 1 b it can therefore be seen that in the transverse sealing seam Q essentially two layers of the packaging film lie on top of one another (cf. areas (a) and (b) in Fig. 1 b). In contrast, in the area of ​​the longitudinal sealing seam L, i.e. in an area (c) in Fig. 1 b, in which the longitudinal sealing seam L and the transverse sealing seam Q intersect, essentially four layers of the packaging film lie on top of one another in the transverse sealing seam Q.

[0007] The lateral overhang of the excess film material in the area of ​​the two lateral ends of the transverse sealing seam Q described above is generally undesirable, as it can lead to disruptions in further processing and / or conveying and / or packaging of the formed packaging units. The lateral film overhang can lead to disadvantages or problems, particularly with products or packaging units to be cartoned, as these can only be stacked or layered in a space-saving manner to a limited extent, which is undesirable with regard to the formation of the most compact secondary or outer packaging possible. In addition, the products to be stacked, for example, in a cardboard outer packaging can catch on one another during conveying and become tangled, which prevents an orderly arrangement in the packaging carton.Finally, the lateral overhang of the excess film material is also disadvantageous from the perspective of an attractive product design or aesthetic product presentation.

[0008] In order to avoid the above disadvantages and problems, it is known to avoid the above-described lateral overhang of the excess film material in the area of ​​the transverse sealing seam Q when producing a packaging unit in a flow-wrapping machine. For this purpose, an additional fold of the packaging material or the packaging film is provided in the area of ​​the two lateral ends of the transverse sealing seam Q before the transverse sealing seam Q is sealed. In this case, 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. including the front and rear transverse sealing seams Q. In other words, the length LQ of the transverse sealing seam Q running transversely to the conveying direction F of the flow-wrapping machine after sealing the transverse sealing seam Q, i.e.In a finished packaging unit V, the width BV of the packaging unit V running transversely to the conveying direction F or the actual width of the product packaged therein is substantially equal. Such a packaging unit V is shown in a plan view in Fig. 2a and in a perspective view in Fig. 3.

[0009] Fig. 2b shows this packaging unit V in a schematic sectional view along the line BB from Fig. 2a. Analogous to Fig. 1b, the section BB therefore extends along the transverse sealing seam Q. In Fig. 2b it can therefore be seen that in the transverse sealing seam Q essentially two layers of the packaging film lie on top of one another (cf. area (a) in Fig. 2b). As in Fig. 1b, here too in the area of ​​the longitudinal sealing seam L, i.e. in an area (c) in Fig. 2b in which the longitudinal sealing seam L and the transverse sealing seam Q intersect, essentially four layers of the packaging film lie on top of one another in the transverse sealing seam Q. Unlike in Fig. 1b, however, in the packaging unit V in Fig. 2b essentially four layers of the packaging film lie on top of one another at the lateral ends of the transverse sealing seam Q, i.e. in areas (d) and (e) in Fig. 2b.

[0010] In order to obtain this shape of the transverse seal seam Q, the film tube is pressed laterally or inwards before sealing the transverse seal seam Q in the area of ​​each lateral end of the transverse seal seam Q and / or in the area of ​​the transition of the respective lateral end of the transverse seal seam Q to the respective side surface S of the packaging unit V. In this process, suitable devices or tools are used to engage or pierce the film tube from the outside, but without penetrating or otherwise damaging the film tube.The film tube is formed and / or folded in such a way that, after sealing the transverse sealing seam Q, a packaging film gusset Z is formed in the region of each lateral end of the transverse sealing seam Q or in the region of the transition from the respective lateral end of the transverse sealing seam Q to the respective lateral surface S of the packaging unit V. Such that the packaging film is folded in the region of each lateral end of the transverse sealing seam Q so that it lies four layers on top of one another (cf. regions (d) and (e) in Fig. 2b). The packaging film gusset Z particularly forms the region in which the film transitions from the lateral four-layer end of the transverse sealing seam Q to the respective, essentially vertically oriented lateral surface S of the packaging unit V, the film running essentially in a single layer and flat or level on the lateral surface S (see Fig. 3).

[0011] In this way, the excess film material described above in connection with Figs. 1 a and 1 b, which arises when the film is folded around the product and when the transverse sealing seam Q is formed, is at least partially pressed laterally into the transverse sealing seam Q and / or the packaging film gusset Z and, to a certain extent, stowed therein.

[0012] The process of forming the packaging film gusset Z described above is also referred to as gusset folding. In a (horizontal) flow-wrapping machine, this process is an additional process step for forming a "gusseted" packaging unit V, in which the packaging width BV is continuously adapted to the product width (i.e., along the entire length of the packaging unit V in the conveying direction F, including the transverse sealing seams Q) (see Figs. 2a and 3). Based on the geometric relationships, it becomes clear that the penetration depth of the gusset fold typically corresponds essentially to half the height of the product or packaging unit V, with the product height extending perpendicular to the conveying plane.

[0013] For the sake of clarity, the gusset fold and the associated elements are generally shown and described below only on one side, i.e., on one side of the packaging unit V. However, it is understood that this is a symmetrical process and that the gusset fold and the associated components in a real packaging machine are provided on both sides, i.e., on both sides of the packaging unit V. In practice, the components of the gusset fold on one side of the packaging unit V are therefore typically located in a mirrored arrangement and design on the other side of the packaging unit V.

[0014] Various devices and methods are known for producing the "twisted" packaging unit V described above.

[0015] In a pneumatic gusset folder, nozzles arranged on both sides are controlled in a timed manner to compress the film tube on both sides using compressed air before the cross-sealing station. However, at high cycle rates, this approach leads to undefined folds and / or additional folds, thus resulting in imperfect gusset folds and overall packaging shapes. In addition to the adverse visual impact of the resulting packaging unit and limited process speed and cycle times, the use of compressed air is fundamentally costly and therefore disadvantageous.

[0016] Alternative devices for producing a "gusseted" packaging unit V are achieved by mechanical gusset folding devices, with which the packaging film is mechanically pressed in. First, a double-crank or parallel-crank gusset folding mechanism 10 is described, which is schematically illustrated in Figs. 4 and 5a to 5c. This four-link coupling mechanism or gusset folding mechanism 10 essentially consists of a first crank element 11 mounted on a first bearing 11a for 360° rotation, a second crank element 12 mounted on a second bearing 12a for 360° rotation, and a coupling element 13 that connects the two crank elements 11, 12. Attached to the coupling element 13 is a folding plate, folding finger, or insertion finger 14, which has a tip 15, also referred to as a coupling point.When the two crank elements 11, 12 are driven by a suitable drive 16 or so-called overdrive, the tip 15 consequently moves on a circular path or coupling point path 17. During this circular movement, the tip 15 alternately engages the packaging film (or pierces it without, however, penetrating the film) in order to press the film in to form the packaging film gusset Z, or is withdrawn from engagement with the packaging film, as will be described in more detail below. As Fig. 4 shows, in the gusset folding mechanism 10 described above, the guide gear is implemented by a parallel crank, with the folding finger 14 being fixed to the coupling 13. In this case, the two cranks 11, 12 must generally be driven identically. This is often implemented by a belt drive (overdrive 16).The corresponding coupling point path 17, along which the tip 15 of the folding finger 14 moves, is therefore always circular. Since the theoretically exact penetration depth of the folding finger 14 into the packaging film corresponds to half the product height, the gusset folding mechanism 10 must be adjustable depending on the respective product width and height. This is often achieved by interchangeable folding fingers 14.

[0017] Figs. 5a to 5c schematically show the movement sequence of the parallel crank gusset folding mechanism 10 of Fig. 4, and in particular the engagement and disengagement of the folding finger 14 with the packaging film between two consecutive products P, which are conveyed from left to right in Figs. 5a to 5c. The drawing plane corresponds to the conveying plane of the packaging machine. Fig. 5a shows, in particular, the insertion of the folding finger 14 into the film tube, Fig. 5b shows, in particular, the synchronous movement of the folding finger 14 with the film tube, and Fig. 5c shows, in particular, the removal of the folding finger 14 from the film tube.

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

[0019] To create the gusset fold, the folding plate or folding finger 14 is controlled in such a way that the packaging material (packaging film) is pressed between the fed-in products P (see Fig. 5a). The actual process of folding the film ends when the maximum penetration depth of the folding finger 14 is reached (see Fig. 5b). While the gusset fold is being created, the tip 15 (coupling point K) of the folding finger 14 moves essentially synchronously with the film web. The movement of the tip 15 thus results essentially from a superposition or combination of a speed component VN of the tip 15 perpendicular to the conveying direction F of the products P or the packaging film, which runs from left to right in Figs. 5a to 5c, and a speed component VF of the tip 15 in or parallel to the conveying direction F, i.e. the speed at which the film web moves in the conveying direction F.5a and 5b thus show the following velocity vectors: VF = film velocity; VK = crosspoint velocity; VN = normal velocity. Fig. 5b shows the time of maximum penetration depth of tip 15 or crosspoint K into the packaging film.

[0020] If the tip 15 disengages from the packaging film or is retracted or leaves the film tube during its further movement on the circular path 17 (see transition from Fig. 5b to Fig. 5c), a collision with the products P must be ruled out. The subsequent range of movement (transition from Fig. 5c to Fig. 5a) concerns the return of the tip 15 of the folding finger 14 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 travel. This range of movement is generally irrelevant for the actual gusset folding process. However, it must be ensured that the tip 15 of the gusset folding mechanism is available again in the position shown in Fig. 5a in time to be able to pierce between the next two products P.

[0021] Due to the mechanical contact between the folding plate or folding finger 14 and the packaging material during piercing, undesirable damage to the packaging material can occur at higher process speeds. For example, the packaging material can be punctured or torn. This problem is caused in particular by the normal speed VN of the folding finger 14 when engaging or piercing the film tube (see Fig. 5a). The normal speed VN refers to the speed component of the folding finger 14 perpendicular to the conveying direction F of the products P or the packaging film, which runs from left to right in Figs. 5a to 5c. Accordingly, performance can be increased by adapting the coupling point path 17, in particular by changing the coupling point path 17 such that the component of the normal speed VN is reduced, resulting in the folding finger 14 piercing the product more gently.This is achieved, for example, by the mechanism described below.

[0022] Since the parallel crank gusset folding mechanism 10, as described above, only allows circular coupling point paths 17, a crank-swing gusset folding mechanism 20, as shown schematically in Fig. 6, is described below as an alternative coupling mechanism. As before, in this known mechanical gusset folding device, the packaging film is mechanically pressed in to form a packaging film gusset Z.

[0023] As Fig. 6 shows, this four-link crank-and-rocker gusset folding mechanism 20 basically consists of a crank element 21 mounted on a first bearing 21a for 360° rotation, and a rocker element 22 mounted on a second bearing 22a for rotation. The rocker element 22 does not rotate a full 360°, but rather oscillates or swings back and forth between two end positions within a specific angular range. The mechanism further comprises a coupling element or connecting element 23 that connects the crank element 21 and the rocker element 22. Attached to the coupling element 23 is a folding plate, folding finger, or insertion finger 24 that has a tip 25, also referred to as a coupling point. In this mechanism, typically only the crank element 21 is driven by a suitable drive 26 and, in particular, rotated 360°.This causes the swing element 22 to perform a pendulum movement over a predetermined angular range due to the coupling via the coupling element 23. Consequently, the tip 25 of the folding finger 24 moves on a path (coupling point path) 27, which is generally no longer a circular path. The actual resulting shape of this path can be modified by selecting the dimensions (e.g. lengths) of the components or elements as appropriate. It should be noted that the paths in the drawings are shown only qualitatively or as examples and not to scale. During this movement, the tip 25 alternately engages or pierces the packaging film in order to press the film in to form the packaging film gusset Z, or is withdrawn from engagement with the packaging film. In the embodiment shown in Fig. 6, the crank element 21 rotates clockwise, for example, in the direction of the arrow shown.However, a counterclockwise direction of rotation is also conceivable. This causes the swinging element 22 to swing back and forth according to the double arrow shown. Due to this systematic movement, the tip 25 of the folding finger 24 moves along the coupling point path 27 shown. It is understood that a suitable reversal or change of the mentioned or shown directions of movement is also conceivable. As mentioned, the drawings are to be understood only qualitatively and / or schematically.

[0024] In such a crank-rocker gusset folding mechanism, the possible coupling point paths are generally described by sixth-order tricircular functions, so that the shape of the coupling point path can be adapted in a variety of ways when designing the mechanism. This enables a significant reduction in the normal speed VN of the folding finger 24 and a related increase in performance. Overall, it should be noted that the kinematics of the coupling mechanism must be taken into account to control the position of the folding finger 24 or its tip 25. Furthermore, the rotating movement of the crank element 21 is generally not uniform, i.e., the rotational movement of the crank element 21 can be accelerated or decelerated in phases.This also serves, in particular, to ensure that the tip 25 of the folding finger 24, after engaging the packaging film between two products P, returns to a position in which it can then engage the film again between the next two products P (which essentially corresponds to the position shown in Fig. 5a). The same applies to the parallel crank gusset folding mechanism 10 described above.

[0025] For the two gusset folding mechanisms 10, 20 described above, the basic principle is that the product width and product height are essentially decisive for the actual process for creating the gusset fold (see the corresponding sequence from Fig. 5a to Fig. 5b to Fig. 5c). With regard to continuous operation of the flow pack machine, however, the return travel of the folding finger to the position in which it can engage the film between the next two products (see the corresponding sequence from Fig. 5c to Fig. 5a) and thus also the product length must be taken into account. Here, the product length refers to the extension of the product in the conveying direction of the packaging machine. For long products, a slow return travel of the folding finger is possible or necessary, which can also be achieved by an additional pause (i.e. phased standstill of the folding finger).For short products, however, a rapid return movement of the folding finger is generally required to ensure that it is available at the starting or starting position (as shown in Fig. 5a) in time for the next insertion into the film. This represents a limiting factor for the performance of conventional packaging machines with gusset folding.

[0026] The variable and sometimes high speeds associated with the aforementioned movement sequences of the coupling mechanism, with correspondingly large accelerations or decelerations at certain times, place a corresponding load on the drive or drive motor driving the respective components of the coupling mechanism. This significantly limits the possible cycle rate for generating the gusset fold and thus the overall performance of known packaging machines.

[0027] It is therefore an object of the present invention to overcome the disadvantages described above. In particular, the invention is intended to increase the speed or cycle rate of generating a gusset fold in a tubular bag packaging unit, especially with comparatively short products to be packaged, and thus the performance of a packaging machine with gusset folding. In particular, the invention is intended to make it possible to avoid the phase-wise large accelerations and / or large decelerations in the movement of the components of a gusset folding coupling mechanism, which cause a correspondingly heavy load on the drive driving the relevant components, as is known in the prior art.

[0028] 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 to be formed in a tubular bag packaging machine according to claim 1 and by a corresponding method according to claim 16. The stated object is also achieved by a tubular bag packaging machine according to claim 17 and by a packaging unit formed from a packaging film according to claim 18.

[0029] The invention thus provides a folding device for folding a packaging film in the region 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 runs essentially in the conveying plane and perpendicular to the conveying direction of the tubular bag packaging machine, wherein the packaging unit to be formed has two side surfaces which run essentially in the conveying direction and perpendicular to the conveying plane of the tubular bag packaging machine, and wherein the folding device has two gusset folding devices, wherein in each case one gusset folding device is arranged essentially outside in each case a side surface of the packaging unit to be formed in the region of the transverse sealing seam to be formed.In the folding device according to the invention, each of the two gusset folding devices further comprises the following features: at least one folding finger which is designed and movable in such a way that it engages laterally from the outside into the side surface of the packaging unit to be formed in the region of the transverse sealing seam to be formed and presses the side surface at least partially inwards essentially in the direction of the transverse sealing seam to be formed, perpendicular to the conveying direction; and at least two coupling mechanisms, wherein each coupling mechanism has a movable first coupling element, a movable second coupling element and a connecting element which is designed such that it connects the first coupling element and the second coupling element to one another; wherein in each case one folding finger is attached to one of the connecting elements of the at least two coupling mechanisms.

[0030] While the known mechanical gusset folding mechanisms 10 and 20 described above (cf. Figs. 5a to 5c and Fig. 6) each have exactly one coupling mechanism, each with two movable coupling elements and a connecting element connecting them, as well as exactly one folding finger attached to the connecting element, the invention provides that a gusset folding mechanism or a gusset folding device has at least one folding finger and at least two coupling mechanisms. Thus, according to the invention, in principle, any number of folding fingers and any number of two or more coupling mechanisms can be provided in a gusset folding mechanism, with one folding finger being attached to each of the coupling mechanisms.According to the invention, it is therefore also possible in principle 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.

[0031] If more than one folding finger is present, the movement of the coupling mechanisms causes the folding fingers to engage the packaging film one after the other and alternately between each two consecutive packaging units to be formed in the flow-wrapping machine, pressing the film inward in the direction of the transverse seal seam to be formed. The transverse seal seam is then sealed, thereby closing the respective packaging unit. This ultimately creates a packaging film gusset essentially at each of the four corners of a finished, essentially cuboid-shaped packaging unit, each of which is separated from the supplied packaging film tube.

[0032] In a preferred embodiment of the folding device according to the invention, each gusset folding device has two folding fingers and two coupling mechanisms, wherein one folding finger is attached to one coupling mechanism in each case.

[0033] In contrast to the known gusset folding mechanisms 10 and 20 described above (cf. Figs. 5a to 5c and Fig. 6), which each have a coupling mechanism with a folding finger, this embodiment of the gusset folding device according to the invention provides two interacting coupling mechanisms, preferably arranged in principle parallel to one another, each with a folding finger. As a result, only every second gusset fold is carried out by one or the same of the two coupling mechanisms, i.e. the two coupling mechanisms with their respective folding fingers alternate in the successive formation of the gusset folds. In this way, the cycle rate of each individual coupling mechanism is halved, while the gusset folding device as a whole achieves the full cycle rate desired for the successive formation of the individual packaging units.

[0034] This avoids or at least reduces the high speeds described above, or the phased, alternating large accelerations and decelerations of the components of the coupling mechanisms, as well as the resulting loads on the drive devices, which are present in the prior art. This ultimately eliminates the need for a highly dynamic or rapid return of the individual folding finger to its starting position for the next folding process, as is otherwise the case in the prior art, particularly for short products. This can be achieved by dispensing with this, or by implementing a correspondingly slower and thus more gentle return movement, since the presence of the second coupling mechanism allows more time for each individual folding finger to return to its starting position.

[0035] As already mentioned above, this approach can in principle be extended according to the invention to any number of coupling mechanisms, each with an associated folding finger per gusset folding device. Depending on the number of coupling mechanisms, the individual folding fingers engage the packaging film one after the other with a phase shift, whereby each individual folding finger must be available less frequently for the film engagement process. This reduces the cycle rate of each individual coupling mechanism, while the gusset folding device as a whole achieves the full cycle rate required for the successive formation of the individual packaging units. As a result, the performance of the gusset folding device and thus of the tubular bag packaging machine as a whole can be increased, since due to the multiple coupling mechanisms in the gusset folding device, the cycle rate and / orthe speed of the gusset folds to be created can be increased accordingly.

[0036] With the folding device according to the invention, higher cycle rates can be achieved across the entire format range for both short and long products. The format range generally refers to the permissible dimensions of the products to be packaged, i.e., the minimum and / or maximum length / height / width of the products.

[0037] It is understood that with an increase in the number of coupling mechanisms and folding fingers per gusset folding device, the mechanical design, spatial arrangement, and control and / or regulation of the (gear) components become correspondingly more complex. Due to the systematic movement and / or combined movement sequences of the components, and given that the multiple folding fingers must always engage the packaging film at essentially the same position and / or in the same plane along the conveyor line, it is necessary to prevent penetrations or overlaps of the movement paths and / or collisions between the components during their movement.

[0038] In a first embodiment of the folding device according to the invention, at least one coupling mechanism of the at least two coupling mechanisms in each of the gusset folding devices is designed such that the first coupling element and the second coupling element are each a crank element which is designed such that it can be rotated about an axis by 360°, wherein the axes of the first and second crank elements run substantially parallel to one another and perpendicular to the conveying plane and perpendicular to the conveying direction of the tubular bag packaging machine. The at least one coupling mechanism thus corresponds to the parallel crank gusset folding mechanism / coupling mechanism 10 described above in connection with Fig. 4 and Fig. 5a to 5c. Depending on the number of cooperating coupling mechanisms in each gusset folding device, in this embodiment one, several or all coupling mechanisms can be as described above, i.e.be designed as a parallel crank mechanism.

[0039] 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 gusset folding devices is designed such that the first coupling element is a crank element configured to be rotatable by 360° about an axis, and the second coupling element is a rocker element configured to be rotatable about an axis and to 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 one another and perpendicular to the conveying plane and perpendicular to the conveying direction of the tubular bag packaging machine. The at least one coupling mechanism thus corresponds to the crank-rocker gusset folding mechanism / coupling mechanism 20 described above in connection with Fig. 6.Depending on the number of cooperating coupling mechanisms in each gusset folding device, in this embodiment one, several or all coupling mechanisms can be designed as described above, ie as a crank rocker mechanism.

[0040] In a combination of the above-described first and second embodiments of the folding device according to the invention, it is thus also possible for at least one coupling mechanism in a gusset folding device to be designed as a parallel crank mechanism and at least one coupling mechanism as a crank-and-rocker mechanism. With exactly two coupling mechanisms in the gusset folding device, a parallel crank mechanism is thus combined with a crank-and-rocker mechanism. If more than two coupling mechanisms are provided in the gusset folding device, one or more parallel crank mechanisms can be combined with one or more crank-and-rocker mechanisms in any desired number.

[0041] In a preferred variant of the above-described second embodiment of the folding device according to the invention, each of the two gusset folding devices has exactly two coupling mechanisms, wherein each of the two coupling mechanisms is designed such that the first coupling element is a crank element configured to be rotatable by 360° about an axis, and the second coupling element is a rocker element configured to be rotatable about an axis and to 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 one another and perpendicular to the conveying plane and perpendicular to the conveying direction of the tubular bag packaging machine. Each of the two coupling mechanisms thus corresponds to the crank-rocker gusset folding mechanism / coupling mechanism 20 described above in connection with Fig. 6.

[0042] Preferably, this variant further provides 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 dimensions, in particular the same length, and that the axis for the rotation of the crank element of the first coupling mechanism is identical or coincides with the axis for the rotation of the crank element of the second coupling mechanism. Furthermore, this variant preferably provides that the swing element of the first coupling mechanism is substantially identical to the swing element of the second coupling mechanism, i.e.,that both swing elements have substantially the same dimensions, in particular the same length, and that the axis for the rotation of the swing element of the first coupling mechanism is identical to or coincides with the axis for the rotation of the swing element of the second coupling mechanism. Furthermore, in this variant, it is preferably provided that the folding finger of the first coupling mechanism is substantially identical to the folding finger of the second coupling mechanism, i.e., that both folding fingers have substantially the same dimensions, in particular the same length.

[0043] In this way, it is ensured that the tips or coupling points of the two folding fingers move on the same or identical path (coupling point path). As described above in connection with the crank-and-rocker gusset folding mechanism / coupling mechanism 20 shown in Fig. 6, this path can have various shapes, whereby the actual resulting shape of the path can be modified in a suitable manner by selecting the dimensions (e.g. lengths) of the components or elements of the coupling mechanism. The two folding fingers can thus engage in the packaging film one after the other or alternately and, according to their, preferably regular, angular spacing, phase-shifted essentially at the same position. For this to happen, however, the components of the coupling mechanisms must also be designed such that they do not collide with one another during their movements and that their movement paths do not penetrate each other.

[0044] The description above for two coupling mechanisms applies accordingly if each of the two gusset folding devices has more than two coupling mechanisms. In this case, the crank elements of all coupling mechanisms are essentially identical to one another, the rocker elements of all coupling mechanisms are essentially identical to one another, and the folding fingers of all coupling mechanisms are essentially identical to one another. The tips or coupling points of all folding fingers then move, in turn, out of phase with their angular spacing, on the same or identical path (coupling point path) and, in turn, engage in the packaging film at essentially the same position. Various forms of drive are possible for bringing about the movement of the components of the coupling mechanisms described above. In a first embodiment, a separate drive device is provided for each crank element of each coupling mechanism.The drive device is designed to control the rotational movement of the crank element, in particular to accelerate and / or decelerate the crank element in phases with a predetermined speed profile and / or to move it at a constant speed.

[0045] This drive variant is particularly relevant when the coupling mechanism is formed by a rocker arm mechanism, in which the crank element is thus driven, while the rocker arm element is only driven indirectly via the connecting element by means of the movement of the crank element, as explained above, for example, in connection with Fig. 6. If, on the other hand, the coupling mechanism is formed by a parallel crank mechanism, as described above, for example, in connection with Fig. 4, generally only one of the two crank elements is driven, while the other crank element is only driven indirectly via an overdrive (e.g. belt drive) and / or the connecting element by means of the movement of the first crank element.

[0046] In the aforementioned embodiment, in which a separate drive device is provided for each crank element of each coupling mechanism, and in the case that the same number of folding fingers and coupling mechanisms (consisting of a crank element and / or rocker element) is provided in the gusset folding device, the drive devices respectively assigned to the crank elements of the coupling mechanisms are preferably designed and synchronized with one another in such a way that the crank elements rotate with the predetermined speed profile in such a way that the folding fingers respectively assigned to the coupling mechanisms engage in the packaging film one after the other with a regular phase offset from one another corresponding to the number of coupling mechanisms.

[0047] If, for example, the gusset folding device has two folding fingers, these engage the film with a phase offset of 180°. Specifically, two coupling mechanisms are provided, with one folding finger each attached to the connecting element of each coupling mechanism in such a way that when the crank elements of the coupling mechanisms are rotated, the folding fingers assigned to the two coupling mechanisms engage the packaging film one after the other with a phase offset of 180°. Similarly, if the gusset folding device has three folding fingers, these engage the film with a phase offset of 120°. If the gusset folding device has even more folding fingers, the value of the phase offset changes as a quotient of 360° according to the number of folding fingers.

[0048] In a second, alternative embodiment of the drive, a single drive device can be provided which is designed to control the rotational movement of all crank elements of the coupling mechanisms, in particular to accelerate and / or decelerate all crank elements simultaneously with a predetermined, equal speed profile in phases and / or to move them at a constant speed

[0049] This drive variant is particularly relevant when the coupling mechanism is formed by a rocker arm mechanism, in which the crank element is thus driven, while the rocker arm element is not directly driven by the drive device. If, on the other hand, the coupling mechanism is formed by a parallel crank mechanism, usually only one of the two crank elements is driven by the drive device, while the other crank element is driven only indirectly via an overdrive and / or the connecting element by means of the movement of the first crank element.

[0050] In the second embodiment mentioned above, in which a single drive device is provided that controls all crank elements uniformly or simultaneously, and again in the case where the same number of folding fingers and coupling mechanisms (consisting of a crank element and / or rocker element) are provided in the gusset folding device, the crank elements of the coupling mechanisms are preferably arranged at equal angular distances from one another. The crank elements then rotate at the predetermined speed profile such that the folding fingers assigned to the coupling mechanisms engage the packaging film one after the other with a regular phase offset from one another corresponding to the number of coupling mechanisms.

[0051] Here too, as above, the following applies: if the gusset folding device has, for example, two folding fingers, these engage in the film with a phase offset of 180°; if the gusset folding device has three folding fingers, these engage in the film with a phase offset of 120°; etc.

[0052] The approach of the second embodiment of the drive described above is advantageous in terms of both process technology, design and cost. This embodiment uses a single drive device, e.g. a servo motor, which drives two identical, coupled crank-and-rocker mechanisms. The phase offset of the cranks and the folding fingers assigned to them is 180°. As already mentioned, the actual movement, e.g. the speed profile, during the return travel of the folding finger to its starting or starting position for the next folding process is irrelevant for the process as a whole. The only important thing is that the folding finger reaches its starting position again in a timely manner, i.e. with precise timing and position, during the return travel.Accordingly, the servo motor can control the gusset folding by the folding finger of the second crank mechanism during the return movement of the folding finger of the first crank mechanism. In other words, both folding fingers move at the same speed profile, which is controlled by the servo motor. This profile is only relevant and coordinated for the gusset folding process by one folding finger, while this profile is irrelevant for the simultaneous return movement of the other folding finger.

[0053] This embodiment, in which a single drive device drives two identical, coupled crank-rocker mechanisms, has the particular advantage, compared to the other embodiment described above, in which each crank-rocker mechanism is controlled by a separate drive device, of a smaller space requirement due to only one drive motor and its simpler spatial arrangement compared to several separate drive motors. In contrast, the advantage of several separate drive motors is that the individual crank mechanisms can be controlled individually and independently of one another if necessary.

[0054] As already mentioned above, in the gusset folding device, each of the at least two coupling mechanisms is designed and arranged in such a way that the first coupling elements (i.e. crank elements), the second coupling elements (i.e. crank elements or rocker elements) and the connecting elements of the at least two coupling mechanisms and / or the folding fingers respectively assigned to the coupling mechanisms do not collide with one another during their movement. In particular, collisions between the folding fingers and / or the other components of the gusset folding device can be ruled out by a somewhat layered or layer-like structure of the gusset folding device. In this case, the first coupling elements, second coupling elements, connecting elements and folding fingers respectively assigned to a coupling mechanism of the at least two coupling mechanisms are arranged ormove in a plane that is arranged essentially parallel to the conveying plane of the flow-wrapping machine. This plane differs from a corresponding plane of another coupling mechanism of the at least two coupling mechanisms, relative to the conveying plane of the flow-wrapping machine.

[0055] Thus, if, for example, two coupling mechanisms are provided, a first plane in which the components of the first coupling mechanism move can be parallel to and, for example, substantially below the conveying plane of the tubular-wrapping machine, while a second plane in which the components of the second coupling mechanism move can be arranged parallel to and, for example, substantially above the conveying plane of the tubular-wrapping machine. It is understood, as explained above, that the actual regions in which the coupling mechanisms move lie laterally outside the conveying path of the products and the film tube, i.e., outside the packaging unit to be formed.Furthermore, it is understood that the folding fingers of the at least two coupling mechanisms must be designed and arranged such that their tips ultimately engage with the packaging film from the outside at essentially the same position in the conveyor line in order to form the packaging film gusset. In the case described above, in which the gusset folding device has two or more coupling mechanisms, each designed as a crank-and-rocker mechanism, the crank elements of the coupling mechanisms can be connected to one another and / or designed such that they form a cranked crankshaft. If two crank-and-rocker coupling mechanisms are provided and interact, each representing a four-link mechanism, the two four-link mechanisms can thus be structurally expanded into a six-link mechanism by means of a common crankshaft.

[0056] With all the embodiments of the invention described above, a folding device is thus created which is designed and operates in such a way that it folds the packaging film in the region of the two side surfaces of the packaging unit to be formed before sealing the transverse sealing seam and separating the film tube into the individual packaging units in such a way that the length of the transverse sealing seam after its sealing essentially corresponds to the width of a product packaged in the packaging unit running transversely to the conveying direction of the tubular bag packaging machine.In this case, after the sealing of the transverse sealing seam and after its separation into a rear transverse sealing seam of a first, preceding packaging unit and a front transverse sealing seam of a second, subsequent packaging unit, a packaging film gusset is formed in the region of each lateral end of each (partial) transverse sealing seam thus formed or in the region of the transition of the respective lateral end of the (partial) transverse sealing seam to the respective side surface of the finished individual packaging unit, which gusset is designed such that the packaging film is folded in the region of each lateral end of each transverse sealing seam such that it lies four layers on top of one another.

[0057] As described above, according to the invention, a folding device is created which comprises at least one folding finger and at least two cooperating coupling mechanisms, wherein each coupling mechanism has a movable first coupling element (crank element), a movable second coupling element (crank element or rocker element) and a connecting element connecting them. The at least one folding finger is attached to one of the connecting elements of the at least two coupling mechanisms. The folding device according to the invention can therefore, in principle, also be operated with only a single folding finger and two or more coupling mechanisms, without removing gear members or components of the coupling mechanisms. The additional gear members of the coupling mechanism which does not have a folding finger (e.g.Crank element, connecting element, swing element, cranked crankshaft) are advantageous from a dynamic perspective, as they achieve mass balancing, i.e., process-related vibrations due to the movement of the entire gusset folder, for example, are significantly reduced. This allows for inertial force balancing through the additional gear elements (which are not combined with a folding finger), thus reducing vibration transmission to the frame or substructure of the flow-wrapping machine, or to the flow-wrapping machine as a whole.

[0058] The invention further provides a method for folding a packaging film in the region of a transverse sealing seam of a packaging unit to be formed in a tubular bag packaging machine, wherein the method is characterized in that it is carried out with a folding device according to the invention as described above.

[0059] The invention further provides a tubular bag packaging machine for forming a packaging unit containing a product from a packaging film, the machine comprising the following features: a transverse sealing device for forming a transverse sealing seam running transversely to the conveying direction of the tubular bag packaging machine in the film tube or on the packaging unit; and a folding device according to the invention, as described above, for folding the packaging film in the region of the transverse sealing seam to be formed. The folding device is arranged upstream of the transverse sealing device in the conveying direction of the tubular bag packaging machine, in particular such that the folding device and the transverse sealing device or their components do not collide with one another during their respective movements.The cross-sealing device typically also includes a knife device, with which the individual packaging units are successively separated from the film tube during the formation of the respective cross-sealing seam. The knife device divides the cross-sealing seam initially formed in the continuous film tube into two partial cross-sealing seams, namely a rear cross-sealing seam of a first, preceding packaging unit and a front cross-sealing seam of a second, subsequent packaging unit.

[0060] Finally, the invention provides a packaging unit which is formed from a packaging film and contains a product, wherein the packaging unit is formed with a folding device according to the invention and / or with a tubular bag packaging machine according to the invention and / or using a method according to the invention, as each has been described above.The finished packaging unit according to the invention has, at its front end and rear end in the conveying direction of the tubular bag packaging machine, a transverse sealing seam running transversely to the conveying direction, wherein the length of each transverse sealing seam substantially corresponds to the width running transversely to the conveying direction of a product packaged in the packaging unit, and wherein in the region of each lateral end of each transverse sealing seam or in the region of the transition of the respective lateral end of the transverse sealing seam to the respective side surface of the packaging unit, a packaging film gusset is formed, which is designed such that the packaging film is folded in the region of each lateral end of each transverse sealing seam such that it lies one on top of the other in four layers.

[0061] Further details and advantages of the invention will become apparent from the following more detailed description of embodiments of the invention with reference to the accompanying drawings.

[0062] Fig. 1 a shows a packaging unit from the prior art in a plan view.

[0063] Fig. 1 b shows the packaging unit from Fig. 1 a in a sectional view along the line AA from Fig. 1a.

[0064] Fig. 2a shows a packaging unit according to the invention in a plan view.

[0065] Fig. 2b shows the packaging unit from Fig. 2a in a sectional view along the line BB from Fig. 2a. Fig. 3 shows the packaging unit from Figs. 2a and 2b in a perspective view.

[0066] Fig. 4 shows a prior art parallel crank gusset folding mechanism.

[0067] Fig. 5a to 5c show the sequence of movements of the parallel crank gusset folding mechanism from Fig. 4.

[0068] Fig. 6 shows a prior art crank-and-swing gusset folding mechanism.

[0069] Fig. 7 shows a combination of a parallel crank gusset folding mechanism with a crank swing gusset folding mechanism according to the invention.

[0070] Fig. 8 shows an embodiment of a combination of two crank-rocker gusset folding mechanisms with separate control according to the invention.

[0071] Fig. 9 shows an embodiment of a combination of two crank-rocker gusset folding mechanisms with coupled control according to the invention.

[0072] Fig. 10 shows an embodiment of the combination of two crank-rocker gusset folding mechanisms with coupled control from Fig. 9.

[0073] Fig. 11a to 11f show the sequence of movements of the combined crank-rocker gusset folding mechanisms from Fig. 8 or Fig. 9.

[0074] The objects shown in Fig. 1a to Fig. 6 were already explained at the beginning in connection with the discussion of the prior art. Insofar as the features of the invention discussed below correspond to the features of the objects shown in Fig. 1a to Fig. 6, reference is made to these previous drawings and the associated description above. As already mentioned above, the drawings (especially Figs. 4 to 9) are merely schematic principle sketches. The movement, drive or passage directions of the components of the coupling mechanisms shown are merely examples and are not to be understood as exhaustive or mandatory. The actual geometry of the coupling point path and its passage direction depend on the respective selected gear dimensions. The sketched coupling point paths of the crank rocker mechanisms are to be understood purely qualitatively and do not necessarily have the shapes shown in practice.

[0075] Fig. 7 shows a gusset folding device 100 formed from a combination of a parallel crank gusset folding mechanism 110 with a crank-and-rocker gusset folding mechanism 120. The parallel crank mechanism 110 shown here essentially corresponds to the known parallel crank mechanism 10 from Fig. 4 and Fig. 5a to 5c. The crank-and-rocker mechanism 120 shown here essentially corresponds to the known crank-and-rocker mechanism 20 from Fig. 6. The folding device 100 of Fig. 7 thus comprises two different and essentially separate gusset folding mechanisms 110, 120, each controlled separately via its own drive device 116, 126.The two gusset folding mechanisms 110, 120 have different coupling point paths 117, 127, namely essentially a circular path 117 in the case of the parallel crank mechanism 110 and essentially a non-circular path 127 in the case of the crank rocker mechanism 120, as described above in connection with Figs. 4 to 6.

[0076] Depending on a desired conveying direction F of the products in Fig. 7, the crank elements 111, 112 of the parallel crank mechanism 110 can rotate, for example, clockwise or counterclockwise. The illustrated crank element 121 of the crank-rocker mechanism 120 rotates, for example (but not necessarily) clockwise in the direction of the arrow shown. However, a counterclockwise direction of rotation is also conceivable. Due to the coupling with the crank element 121 via the connecting element 123, the rocker element 122 of the crank-rocker mechanism 120 swings back and forth in accordance with the double arrow shown. Consequently, 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 along their respective coupling point paths 117, 127.

[0077] It goes without saying that a suitable reversal or change of the aforementioned directions of movement is also conceivable. As already mentioned above, it should be noted that the representations of the crank mechanisms in the drawings are merely schematic, exemplary, and purely qualitative. Accordingly, the associated coupling point paths are also merely exemplary and schematically sketched. To the extent that specific directions of movement or rotation of the components are mentioned here, this is merely exemplary and not exhaustive.

[0078] Fig. 7 shows the two gusset folding mechanisms 110, 120 and thus their two coupling point paths 117, 127 spatially separated from one another. The tips 115, 125 of the two folding fingers 114, 124 thus engage the packaging film at different positions in the conveyor line of the packaging machine to form a packaging film gusset. However, a suitable superposition of the two gusset folding mechanisms 110, 120 and thus their coupling point paths 117, 127 is also conceivable such that the two tips 115, 125 engage the packaging film at essentially the same position in the conveyor line. The two gusset folding mechanisms 110, 120 can be driven and controlled such that the two tips 115, 125 engage the film alternately, with a phase shift.

[0079] Fig. 8 shows a gusset folding device 200 formed from a combination of two identical crank-and-rocker gusset folding mechanisms 220 and 230. The two crank-and-rocker mechanisms 220, 230, each taken individually, essentially correspond to the known crank-and-rocker mechanism 20 from Fig. 6.

[0080] The first crank-and-rocker gusset folding mechanism 220 thus consists of a first crank element 221 that can be rotated through 360°, and a rotatable first rocker element 222 that oscillates 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 having a tip 225 is attached to the coupling element 223. The crank element 221 is driven by a suitable first drive 226 and is thereby rotated, in particular, through 360°. Due to the coupling via the coupling element 223, the rocker element 222 thus performs a pendulum movement over a predetermined angular range (see the double arrow drawn in). Consequently, the tip 225 of the folding finger 224 moves on the coupling point path 227. In the embodiment shown in Fig. 8, the crank element 221 rotates according to the direction of the arrow shown, for example (but not necessarily) clockwise.However, a counterclockwise direction of rotation is also conceivable. This causes the pendulum movement of the swing element 222. Due to this systematic movement, the tip 225 of the folding finger 224 moves along the schematically shown coupling point path 227. During this movement, the tip 225 alternately engages the packaging film to form a packaging film gusset Z or is retracted from engagement with the packaging film. In principle, the direction of travel or movement of the mechanism or its components depends on the actual dimensions of the mechanism.

[0081] The second crank-and-rocker gusset folding mechanism 230 of the gusset folding device 200 (shown in Fig. 8 in a dashed-dotted line) is fundamentally identical to the first crank-and-rocker gusset folding mechanism 220 (shown in Fig. 8 in a solid line). The second crank-and-rocker mechanism 230 thus consists of a rotatable second crank element 231 and a rotatable second rocker element 232, which are connected to one another via a second coupling element or connecting element 233. A folding finger 234 having a tip 235 is attached to the coupling element 233. The second crank element 231 is driven by a suitable second drive 236 and is rotated, in particular, by 360°. Due to the coupling via the coupling element 233, the second rocker element 232 thus performs a pendulum movement over a predetermined angular range (see the double arrow drawn in).Consequently, the tip 235 of the folding finger 234 moves on the coupling point path 237. In the embodiment shown in Fig. 8, the second crank element 231 (like the first crank element 221) also rotates in the direction of the arrow shown, for example (but not necessarily) clockwise, and thus causes the pendulum movement of the second rocker element 232 and the movement of the tip 235 of the folding finger 234 on the coupling point path 237. In the course of this movement, the tip 235 alternately engages the packaging film to form a packaging film gusset Z or is withdrawn from engagement with the packaging film. Here, too, the relationships shown are only exemplary, to be understood schematically, and here, too, the direction of travel or movement of the mechanism or its components depends on the actual dimensions of the mechanism.

[0082] As Fig. 8 shows, the coupling point paths 227 and 237 of the two crank-rocker gusset folding mechanisms 220 and 230 are identical and congruent. This requires, in particular, that the corresponding components of the two folding mechanisms 220, 230 are essentially identical, particularly with regard to their dimensions and functionality. In addition, the two crank elements 221, 231 must, in principle, be mounted on an identical and co-located bearing 221a, 231a. Accordingly, the two rocker elements 222, 232 must, in principle, be mounted on an identical and co-located bearing 222a, 232a.

[0083] The two crank-and-rocker gusset folding mechanisms 220 and 230 of Fig. 8 are driven and controlled separately, i.e. each for itself and in principle independently of one another. For this purpose, a separate drive device 226, 236 is provided in each case, e.g. a servo motor. Preferably, however, the two drive devices 226, 236 are controlled such that the tips 225, 235 of the two folding fingers 224, 234 move on the coupling point path 227, 237 in such a way that the tips 225, 235 ultimately engage in the packaging film with a phase offset of 180°, essentially at the same position in the conveyor path. For this purpose, it is not absolutely necessary for the two tips 225, 235 to move continuously at the same and / or constant speed and / or at the same angular distance from one another on the coupling point path 227, 237.It is only essential that the tips 225, 235 are alternately available at essentially the same position for engagement in the packaging film in terms of time and location.

[0084] It is understood that the two independent drive devices 226, 236 can be flexibly and individually controlled as needed so that the tips 225, 235 move on the coupling point path 227, 237 at varying individual speeds and / or not with a phase shift of 180° but with a different, non-symmetrical or irregular phase shift, or even with a variable phase shift. This may be desirable, for example, if the successive products in the conveyor line of the packaging machine have different formats and / or sizes.

[0085] Fig. 9 shows a gusset folding device 200 that essentially corresponds to the gusset folding device 200 shown in Fig. 8, i.e., is formed from a combination of two identical crank-and-rocker gusset folding mechanisms 220 and 230. Regarding the individual components of these two gusset folding mechanisms 220 and 230 and their basic function, reference is made to Fig. 8 and the associated description above.

[0086] The embodiment of Fig. 9 differs from the embodiment of Fig. 8, however, in that now only a single drive device 246 is provided, e.g. a servo motor, which jointly drives and controls the first crank element 221 and the second crank element 231. For this purpose, the first crank element 221 and the second crank element 231 are coupled to one another, preferably fixedly connected to one another. As shown in Fig. 9, the two crank elements 221 and 231 are preferably connected to one another in a line with regard to their longitudinal extent, i.e. at an angle of 180°. Due to the drive by the common drive device 246, the tips 225, 235 of the two folding fingers 224, 234 thus move continuously at the same speed and at the same, fixed angular distance from one another on the identical coupling point path 227, 237. In the embodiment shown in Fig.9, the tips 225, 235 thus move with a phase offset of 180° on the coupling point path 227, 237 and thus alternately engage the packaging film at essentially the same position in the conveyor line with precise timing and location.

[0087] In this embodiment of a coupled control of the two gusset folding mechanisms 220 and 230, it is therefore not possible for the tips 225, 235 to move at changing and / or individual speeds and / or a changing phase offset from one another on the coupling point path 227, 237. However, it is conceivable that the two crank elements 221 and 231 are not connected to one another linearly with respect to their longitudinal extent, i.e. at an angle other than 180°. The two tips 225, 235 then move with an unequal, non-symmetrical, but fixed phase offset on the coupling point path 227, 237, which alternately corresponds to the larger and the smaller angle at which the two crank elements 221 and 231 are connected to one another.

[0088] Fig. 10 shows an exemplary structural embodiment of the combination of the two crank-rocker gusset folding mechanisms with coupled control from Fig. 9. The two four-link gusset folding mechanisms 220, 230 of Fig. 9 are structurally expanded here by a common cranked crankshaft 341 to form a six-link mechanism of a gusset folding device 300.

[0089] The cranked crankshaft 341 comprises the first crank element 321 of the first crank-rocker gusset folding mechanism 320 and the second crank element 331 of the second crank-rocker gusset folding mechanism 330. The first crank element 321 and the second crank element 331 are thus rigidly connected to one another at an angle of 180°. The first crank-rocker gusset folding mechanism 320 further comprises a first coupling element or connecting element 323 and a first rocker element 322. The second crank-rocker gusset folding mechanism 330 further comprises a second coupling element or connecting element 333 and a second rocker element 332. A first folding finger 324, which has a tip 325, is attached to the first coupling element 323. A second folding finger 334, which has a tip 335, is attached to the second coupling element 333.

[0090] The cranked crankshaft 341 is rotatably mounted on a bearing 341a and is driven and controlled by a drive device 346, e.g. a servo motor, in particular rotated 360° around the bearing 341a. Due to the rotation of the crankshaft 341 and the coupling via the coupling elements 323, 333, the first and second swing elements 322, 332, which are mounted on a common bearing 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 such that their tips 325, 335 ultimately engage the packaging film alternately at essentially the same position in the conveyor line of the packaging machine with a phase offset of 180°, in order to form a packaging film gusset therein. From Fig. 10 it can be seen that the two crank-rocker gusset folding mechanisms 320, 330 with their respective components are essentially in different planes or positions orare arranged in layers and move essentially in these different planes. This prevents a collision of the components of the two crank-and-rocker gusset folding mechanisms 320, 330 during their movements. The two folding fingers 324, 334 and / or their tips 325, 335 are designed, e.g., curved, such that the tips 325, 335 alternately engage the packaging film in essentially the same position and / or plane in the conveyor line of the packaging machine.

[0091] Figs. 11a to 11f show an exemplary movement sequence of the gusset folding device 200 of Fig. 8 or Fig. 9, formed from the combined crank-and-rocker gusset folding mechanisms 220, 230. The reference numerals used in Figs. 11a to 11f correspond to the reference numerals used in Figs. 8 or 9 and thus designate the same components. The first crank-and-rocker gusset folding mechanism 220 is shown in solid lines in Figs. 11a to 11f, while the second crank-and-rocker gusset folding mechanism 230 is shown in dashed lines in these figures.

[0092] 11 a to 11 f, the products P1, P2, P3, etc. are conveyed from right to left in the conveying direction F. The first and second folding fingers 224, 234 move here in principle cyclically in such a way that a folding finger 224, 234 alternately coming from the bottom right engages with its respective tip 225, 235 upwards into the gap existing between two consecutive products P1, P2, P3, moves further here with the product flow in the conveying direction F, and then exits the product flow to the bottom left, before subsequently returning to the right to its starting position for a next cycle. The two folding fingers 224, 234 therefore preferably move here in such a way that they engage in the packaging film alternately between two consecutive products with a phase offset of 180° to one another.

[0093] The first crank element 221 is connected linearly, i.e., at an angle of 180°, to the second crank element 231. The two crank elements 221, 231 rotate counterclockwise about a common bearing point 221a, 231a by means of one or more suitable drive devices. As a result, the first and second swing elements 222, 232, mounted on a common bearing point 222a, 232a, swing back and forth. As can be seen in Fig. 11a, the first folding finger 224 engages from below into the gap between the products P1 and P2.

[0094] As the two crank elements 221, 231 continue to rotate, the first folding finger 225 reaches its maximum engagement depth or penetration depth in the gap between the products P1 and P2 (see Fig. 11 b). Upon further rotation of the two crank elements 221, 231 counterclockwise, the first folding finger 224 exits downward from the conveyor line, while the second folding finger 234 approaches the conveyor line from the bottom right (see Fig. 11 c) to then engage in the gap between the product P2 and the following product P3 (see Fig. 11 d). This position of the second folding finger 234 and the components of the second gusset folding mechanism 230 assigned to it essentially corresponds to the position of the first folding finger 224 and the components of the first gusset folding mechanism 220 assigned to it shown in Fig. 11 a.

[0095] As the two crank elements 221, 231 continue to rotate, the second folding finger 234 reaches its maximum engagement depth in the gap between the products P2 and P3 (see Fig. 11 e). This position of the second folding finger 234 and the components of the second gusset folding mechanism 230 associated with it essentially corresponds to the position of the first folding finger 224 and the components of the first gusset folding mechanism 220 associated with it shown in Fig. 11 b.

[0096] Upon further counterclockwise rotation of the two crank elements 221, 231, the second folding finger 234 exits downward from the product stream, while the first folding finger 224 again approaches the conveyor line from the bottom right (see Fig. 11 f) to then engage in the gap between the product P3 and the following product. The position of the second folding finger 234 shown in Fig. 11 f and the components of the second gusset folding mechanism 230 assigned to it essentially corresponds to the position of the first folding finger 224 shown in Fig. 11 c and the components of the first gusset folding mechanism 220 assigned to it.

[0097] The gusset folding devices shown in Fig. 8 to Fig. 11f always comprise, by way of example, two coupling mechanisms and two folding fingers, which preferably move with a phase offset of 180° to one another and alternately engage the packaging film to form the gusset. As explained above, it is also possible in principle to provide more than two interacting coupling mechanisms. It is also possible in principle to have only a single folding finger or more than two folding fingers. However, compared to the variant with two coupling mechanisms and two folding fingers, more than two coupling mechanisms and more than two folding fingers entail a correspondingly greater design and control complexity.

Claims

Patent claims 1. Folding device for folding a packaging film in the region of a transverse sealing seam (Q) to be formed of a packaging unit (V) to be formed in a tubular bag packaging machine, wherein the transverse sealing seam (Q) runs essentially in the conveying plane and perpendicular to the conveying direction (F) of the tubular bag packaging machine, wherein the packaging unit (V) to be formed has two side surfaces (S) that run essentially in the conveying direction (F) and perpendicular to the conveying plane of the tubular bag packaging machine, wherein the folding device has two gusset folding devices (100; 200; 300), wherein each gusset folding device (100; 200; 300) is arranged essentially outside a respective side surface (S) of the packaging unit (V) to be formed in the region of the transverse sealing seam (Q) to be formed, characterized in that each of the two gusset folding devices (100; 200; 300) has the following features: - at least one folding finger (114, 124; 224, 234; 324, 334) which is designed and movable in such a way that it engages laterally from the outside in the region of the transverse sealing seam (Q) to be formed into the side surface (S) of the packaging unit (V) to be formed and presses the side surface (S) at least partially inwards essentially in the direction of the transverse sealing seam (Q) to be formed perpendicular 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) has the following features: o a movable first coupling element (111, 121; 221, 231; 321, 331), o a movable second coupling element (112, 122; 222, 232; 322, 332), o a connecting element (113, 123; 223, 233; 323, 333) which is designed 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) together; - wherein a folding finger (114, 124; 224, 234; 324, 334) is attached to one of the connecting elements (113, 123; 223, 233; 323, 333) of the at least two coupling mechanisms (110, 120; 220, 230; 320, 330).

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

3. Folding device according to claim 1 or 2, wherein at least one coupling mechanism (110) of the at least two coupling mechanisms (110, 120) is designed such that the first coupling element (111) and the second coupling element (112) is each a crank element which is designed such that it can be rotated about an axis by 360°, wherein the axes of the first and the second crank element (111, 112) run substantially parallel to one another and perpendicular to the conveying plane and perpendicular to the conveying direction (F) of the tubular bag packaging machine.

4. Folding device according to one of claims 1 to 3, wherein at least one coupling mechanism (120; 220, 230; 320, 330) of the at least two coupling mechanisms (110, 120; 220, 230; 320, 330) is designed such that the first coupling element (121; 221, 231; 321, 331) is a crank element which is designed such that it can be rotated about an axis by 360°, and that the second coupling element (122; 222, 232; 322, 332) is a swing element which is designed such that it can be rotated about an axis and swings back and forth between two end positions, wherein the axis of the crank element (121; 221, 231; 321, 331 ) and the axis of the swing element (122; 222, 232; 322, 332) run substantially parallel to each other and perpendicular to the conveying plane and perpendicular to the conveying direction (F) of the tubular bag packaging machine.

5. Folding device according to claim 4, wherein each of the two gusset folding devices (200; 300) has two coupling mechanisms (220, 230; 320, 330), wherein each of the two coupling mechanisms (220, 230; 320, 330) is designed such that the first coupling element is a crank element (221, 231; 321, 331) which is designed such that it is rotatable about an axis by 360°, and that the second coupling element is a swing element (222, 232; 322, 332) which is designed such that it is rotatable about an axis and oscillates back and forth between two end positions, wherein the axis of the crank element (221, 231; 321, 331) and the axis of the swing element (222, 232; 322, 332) run substantially parallel to one another and perpendicular to the conveying plane and perpendicular to the conveying direction (F) of the tubular bag packaging machine.

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

7. Folding device according to one of claims 3 to 6, wherein it has a drive device (226, 236) for each crank element (221, 231), wherein the drive device (226, 236) is designed to control the rotational movement of the crank element (221, 231), in particular to accelerate and / or decelerate the crank element (221, 231) in phases with a predetermined speed profile and / or to move it at a constant speed.

8. Folding device according to claim 7, wherein the gusset folding device (200) comprises the same number of folding fingers (224, 234) and coupling mechanisms (220, 230), and wherein the drive devices (226, 236) respectively assigned to the crank elements (221, 231) of the coupling mechanisms (220, 230) are designed and synchronized with one another in such a way that the crank elements (221, 231) rotate with the predetermined speed profile in such a way that the folding fingers (224, 234) respectively assigned to the coupling mechanisms (220, 230) engage in the packaging film one after the other with a regular phase offset from one another corresponding to the number of coupling mechanisms (220, 230) in the region of the transverse sealing seam (Q) to be formed of successive packaging units (V).

9. Folding device according to one of claims 3 to 6, wherein it comprises a drive device (246; 346) which is designed to control the rotational movement of all crank elements (221, 231; 321, 331), in particular to accelerate and / or decelerate all crank elements (221, 231; 321, 331) simultaneously with a predetermined, equal speed profile in phases and / or to move them at a constant speed.

10. Folding device according to claim 9, wherein the gusset folding device (200; 300) comprises the same number of folding fingers (224, 234; 324, 334) and coupling mechanisms (220, 230; 320, 330), and wherein the crank elements (221, 231; 321, 331) of the coupling mechanisms (220, 230; 320, 330) are arranged at equal angular distances from one another, so that the crank elements (221, 231; 321, 331) rotate with the predetermined speed profile in such a way that the folding fingers (224, 234; 324, 334) respectively assigned to the coupling mechanisms (220, 230; 320, 330) are successively rotated with one of the number of Coupling mechanisms (220, 230; 320, 330) engage in the packaging film with a corresponding regular phase offset to one another in the region of the transverse sealing seam (Q) to be formed of successive packaging units (V).

11. Folding device according to claim 8 or 10, wherein it comprises two coupling mechanisms (220, 230; 320, 330), wherein a folding finger (224, 234; 324, 334) is attached to the connecting element (223, 233; 323, 333) of each coupling mechanism (220, 230; 320, 330) in such a way that upon rotation of the crank elements (221, 231 ; 321 , 331 ) of the coupling mechanisms (220, 230; 320, 330), the folding fingers (224, 234; 324, 334) respectively assigned to the two coupling mechanisms (220, 230; 320, 330) engage in the packaging film one after the other with a phase offset of 180° to one another.

12. Folding device according to one of claims 9 to 11, wherein the crank elements (321, 331) of the coupling mechanisms (320, 330) are connected to one another in such a way that they form a cranked crankshaft (341).

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

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

15. Folding device according to one of the preceding claims, wherein it is designed such that it folds the packaging film in the region of the two side surfaces (S) of the packaging unit (V) to be formed before sealing the transverse sealing seam (Q) such that the length (LQ) of the transverse sealing seam (Q) after its sealing substantially corresponds to the length transverse to the conveying direction (F) of the tubular bag packaging machine. machine running width (BV) of a product (P) packed in the packaging unit (V), and that after sealing the transverse sealing seam (Q) in the region of each lateral end of the transverse sealing seam (Q) or in the region of the transition of the respective lateral end of the transverse sealing seam (Q) to the respective side surface (S) of the packaging unit (V), a packaging film gusset (Z) is formed, which is designed such that the packaging film in the region of each lateral end of the transverse sealing seam (Q) is folded such that it lies four layers on top of one another.

16. A method for folding a packaging film in the region of a transverse sealing seam (Q) of a packaging unit (V) to be formed in a tubular bag packaging machine, characterized in that it is carried out with a folding device according to 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: - a transverse sealing device for forming a transverse sealing seam (Q) on the packaging unit (V) running transversely to the conveying direction (F) of the tubular bag packaging machine; and - a folding device for folding the packaging film in the region of the transverse sealing seam (Q) to be formed according to one of claims 1 to 15; - wherein the folding device is arranged upstream of the transverse sealing device in the conveying direction (F) of the tubular bag packaging machine.

18. Packaging unit (V) which is formed from a packaging film and contains a product (P), characterized in that the packaging unit (V) is formed with a folding device according to one of claims 1 to 15 and / or with a tubular bag packaging machine according to claim 17 and / or using a method according to claim 16, wherein the finished packaging unit (V) has at its front end and rear end in the conveying direction (F) of the tubular bag packaging machine a transverse sealing seam (Q) running 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 a product (P) packaged in the packaging unit (V) running transversely to the conveying direction (F) of the tubular bag packaging machine, and wherein in the region of each lateral end of each transverse sealing seam (Q) or in the region of the transition of the respective lateral end of the transverse sealing seam (Q) to the respective side surface (S) of the packaging unit (V), a packaging film gusset (Z) is formed, which is designed such that the packaging film is folded in the region of each lateral end of each transverse sealing seam (Q) such that it lies four layers on top of one another.

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