Mechanism for actuating tenter clips of a tenter chain which have flaps

Abstract

A description is given of a mechanism for actuating tenter clips (2) of a film-stretching installation, which have flaps (1) and run at the speed at which a tenter chain (3) moves, to transfer the clips from an open position, not clamping a film, into a closed position, clamping the film, in which mechanism the flaps (1) are made to collide with a flipping means (6), in the form of a belt loop (8), while they are running past the flipping means. The belt loop (8) is guided by deflecting rollers (7). The belt loop (8) is inclined at an angle to the path of movement of the tenter chain (3). The circulating speed of the belt loop (8) is synchronized with the speed of movement of the tenter clips (2). The speed of movement of the tenter chain (3) is 500 m / min to 750 m / min. As the flaps (1) in the open position collide with the belt loop (8), they each gently flip into the closed position.

Description

[0001] DEVICE FOR ACTUATING CLIPS OF A CLIP CHAIN ​​HAVING FLAPS

[0002] The invention relates to a device for actuating clips having flaps of a clip chain which is used in film stretching systems.

[0003] Such film stretching systems typically feature rotating clips arranged in clip chains that clamp the edges of the film to be stretched or treated. The clamping occurs as the film passes through the film stretching system. For the film to leave the stretching system, the clamping flap of the clip must be moved from the clamping position to the release position. When not clamped, the clips in the respective clip chain return to the film inlet into the system, where the flaps of the clip are moved back to the clamping position.

[0004] Various devices are known for moving the flaps of the clamps into the clamping position. For example, so-called clamp closer wheels are provided for this purpose. These have concave areas on their circumference. These interact with convex areas for engaging the concave areas of the clamp flaps in such a way that the flaps of the clamps slide in the concave areas and are moved from the open position into the clamping position against a spring force. Such clamp closer wheels are used for single-flap clamps as well as for double-flap clamps. Due to the geometry of the clamp closer wheel, the length of the sliding path of the respective flap on the concave area of ​​the clamp closer wheel is relatively short, resulting in high loads on the closer wheel due to the relatively high friction and pressure forces absorbed by the flaps.These loads and problems also occur with an opening wheel, where the clamps are moved from the clamping position to the release position. The high loads often lead to damage to the clamps, which may result in relatively high repair costs due to the need to replace these clamps. Such closing wheels or opening wheels perform the closing movement within a sliding path of the flaps on the closing wheel or opening wheel of 30 to 40 mm. Furthermore, so-called magnetic closers or openers are known, in which the closing or opening movement of the clamp flaps is effected by magnetic force. This requires that at least parts of the clamp flaps are ferromagnetic. With such magnetic closers or magnetic openers, relatively long travels of, for example, up to 250 to 350 mm can be achieved.

[0005] For lower film speeds significantly below 500 m / min, mechanical closers and openers can be used satisfactorily over extended periods. However, the trend toward higher film speeds of 700 m / min and more significantly exceeds the capabilities of reliable use of mechanical systems due to the resulting overloads and risk of breakage. While such high film speeds are possible with magnetic closers and openers, these systems are quite costly. Furthermore, magnetic closers and openers are not suitable for retrofitting existing systems without ferromagnetic flaps on the clamps.

[0006] DE 34 23 901 A1 describes a clamp for web tentering machines, enabling moderate movement speeds of up to 300 m / min. Higher movement speeds are not considered due to the high wear and tear. The described clamp is implemented using a pressing-down device with a constant movement path. The pressing-down device is designed as a continuously rotating, vertically acting closer. A spring-loaded locking device ensures that the clamp flaps are reliably held in their open position during the return travel from the tentering machine outlet to the tentering machine inlet. To ensure that a purely vertically directed pressing force can be exerted on the corresponding rocker arm to close the flap, the known clamp is designed to be very low.Due to acceptable noise levels, among other things, movement speeds of over 300 m / min are excluded from the outset.

[0007] The object of the present invention is therefore to provide a closing device or opening device for the flaps of the clamps, in which a relatively long travel path from the opening position or open position to the spring-loaded closed position in the range of 150 to 200 mm is possible and which also reliably enables high belt speeds up to, for example, 700 m / min or even more. Furthermore, the closing device or opening device according to the invention is intended to reduce the kinetic energy applied to the clamps or flaps for the purpose of closing, and thus the closing force or opening force, as well as the noise generation.

[0008] This object is achieved with a device having the features according to claim 1. Expedient further developments are defined in the appended claims.

[0009] According to the invention, a belt closer or belt opener is provided as a clip closer or clip opener, which is formed from a belt rotating around at least two deflection rollers, which device is arranged at an oblique angle in space and has a rotational speed which is synchronized with the movement speed of the clips, wherein the oblique angle arrangement in space enables the clips to be moved from the closed position to the open position or from the open position to the closed position over an adjustable movement path.

[0010] According to the invention, the device for actuating clips of a film stretching system, which clips have flaps and move at a movement speed of a clip chain, has a tilting device by means of which the flaps are moved from an open position, which does not clamp a film as it passes through a film stretching system, to a closed position, which clamps the film. As they pass the tilting device, the flaps collide with the tilting device, wherein the tilting device is arranged in the path of the clips in the region of the film entering the film stretching system. Likewise, in the region of the film exiting the film stretching system, it can be provided that, by means of said tilting device, the flaps of the clips are moved from the clamping position to the non-clamping open position, in which the film is no longer held by the clips.The tilting device, which tilts the flaps, is designed as a belt loop arranged at an oblique angle in space and guided by deflection rollers. Due to this design of the tilting device as a belt loop, the device according to the invention is also referred to as a belt closer, since the belt is designed as a belt, preferably a toothed belt. The design as a toothed belt has the advantage that the belt running around the deflection rollers engages in corresponding recesses on the deflection rollers, so that the belt is guided around the deflection rollers with essentially no slippage. As the flaps of the clamps collide, they run along with the belt loop on the outside and, after a set path of movement, are pressed from the open position towards the closed position until they pass a tipping point, after which the tilted flaps are in their closed position, i.e. in their position clamping the film.

[0011] According to the invention, the belt loop arranged at an oblique angle in space can be adjusted and arranged as the actual tilting device with regard to its angle to the flaps of the clips of the clip chain, so that the entry points of the flaps of the clips on the outside of the belt or belt of the belt loop and thus the length of contact of the flaps of the clips when running in contact with the outside of the belt can be adjusted. The adjustment of the length of contact of the flaps on the belt loop should be as large as possible, i.e. preferably in a range of 120 to 250 mm, in particular 150 to 200 mm, in particular 120 to 150 mm, so that loads resulting from the necessary exertion of the tilting forces of the flaps from the open position to the clamped position can be reliably maintained even at higher belt running speeds of well over 500 m / min, in particular 750 m / min or more."Reliably maintained" means that even during extended operation, no component damage due to overload occurs, especially on the clamp flaps. Preferably, the deflection rollers are adjustable in the direction of travel of the circulating belt between the deflection rollers, allowing the tension of the circulating belt to be adjusted.

[0012] With an embodiment according to the present invention, the flaps on the outside of the band run smoothly, ie without jerking, and execute a corresponding movement path in contact with the outside of the band, namely up to the tipping point of the flaps, at which they spring into the clamping positions.

[0013] Preferably, the flaps converge or collide with the belt loop at such an acute angle that the flaps hit the belt loop smoothly, at least where they meet. This not only reduces the loads on the flaps or clips, but also minimizes wear on the belt loop. According to the definition of mechanics, "smooth" means that the mathematical second derivative of the motion curve is continuous. Since such a motion curve can only be maintained theoretically, in this context it should be understood that the flaps hit the belt so gently that this occurs largely without jerking. The flaps therefore hit the outside of the belt tangentially.

[0014] Furthermore, the flaps preferably travel along the belt loop over a preferably adjustable contact length. "Contact length" is understood to be the length at which the flaps are in contact with the belt loop. When the tipping point is reached, the spring causes the flaps of the clamps to spring into the clamping position, in which the flaps no longer make contact with the outside of the belt loop.

[0015] Preferably, this contact length can be adjusted by adjusting the tilting device's inclination angle relative to the travel path of the flaps. The "inclination angle" refers to the angle of skew of the tilting device in space, which the tilting device forms relative to the travel path of the flaps.

[0016] The term “tilt angle” is understood to mean the angle of obliquity of the tilting device by which the longitudinal axis of its drive element is inclined from the vertical.

[0017] Preferably, the contact length is achieved by means of a first actuating cylinder via an eccentric, by means of which the spatial position of the tilting device can be adjusted or set. This adjustability of the contact length via the angle of inclination of the tilting device represents a particular advantage over the flap closing devices previously known in the prior art. In addition to adjusting the contact length via the angle of inclination of the tilting device, the contact length can be adjusted by displacing the tilting device via elongated holes provided in its holder. The additional arrangement of elongated holes offers the advantage of extending the contact path of the flaps on the outside of the belt loop without having to change the angle of inclination of the tilting device to the travel path of the flaps.Thus, if an optimal angle of inclination is available with regard to the load occurring, the contact path can still be extended or, if necessary, shortened by adjusting it via the elongated holes.

[0018] The first actuating cylinder adjusts the tilting mechanism to its tilt angle after the entire tilting mechanism has been pivoted into its operating position, i.e., into a position where the flaps collide with the tilting mechanism. The pivoting into and out of the operating position is performed by a second actuating cylinder.

[0019] Preferably, the band of the loop or belt is made of a material that exhibits at least a certain degree of elasticity, so that the loop inherently has a length reserve. This length reserve is capable of compensating for deviations in the impact points on the outside of the loop between the individual flaps of the clips, ensuring that the flaps of the clips impact the outer sides of the band with a substantially smooth impact, even despite the existing deviations.

[0020] Since a magnetic actuation of the flaps of the clamps is not required by the provision of a tilting device in the form of a belt loop or a belt closer, the flaps of the clamps are preferably made of inexpensive non-ferromagnetic material.

[0021] Preferably, the clips, i.e., the clip chain, run at a speed of at least 500 m / min. Even at clip chain speeds of, for example, 750 m / min or even more, the dynamics of the flap movement are reliably controlled by the belt closer according to the invention.

[0022] The inventive belt loop used as a tilting device is designed so that the flaps can be used both as single flaps or as double flaps. As the flaps move along the outside of the belt loop, the belt allows for a path of movement in the tilting direction of the flaps. This means that, by means of the tilting device, the flaps can be completely pivoted from their non-clamping position, which collides with the outside of the belt loop, into their clamping position.

[0023] It is particularly advantageous to design the belt loop as a toothed belt, the teeth of which point towards the interior of the belt loop and engage in corresponding recesses on the deflection rollers, so that the belt loop in the form of a toothed belt rotates essentially slip-free. In order to maintain the desired tension of the circulating belt loop, the distance between the deflection rollers can be adjusted in the direction of travel of the belt. It is also possible, however, to arrange an additional tensioning element in the form of another deflection roller inside the belt loop. All deflection rollers can be driven separately. It is also possible, however, for only one or some of the deflection rollers to be actively driven. This drive can preferably be a servo motor, which is synchronized with the speed of the clip chain via a control system.By synchronizing the speed of the belt loop with the speed of the clips and their flaps moved by the clip chain, the belt of the belt loop does not experience any significant wear when the flaps collide or move along on the outside of the belt loop, since the flaps and belt have the same speed while moving along.

[0024] Instead of a timing belt, the belt of the belt loop can also be a flat belt or a chain. In addition to the positive transmission of forces from the pulleys to the timing belt, it is also particularly well suited for the application according to the invention because the timing belt is generally lubrication-free and slip-free. A chain also provides essentially slip-free operation, but the chain must be lubricated, which is why a timing belt is the preferred belt for a belt loop.

[0025] In order to minimize wear, which may still occur to a certain extent due to frictional forces, it is preferably provided that a wear-resistant layer is provided on the outside of the tilting device, which is designed as a belt loop, on the side facing the flaps. It is sufficient if the wear-resistant layer is arranged only in the area of ​​the collision path or contact path of the flaps with the outside of the belt loop.

[0026] Instead of a wear-resistant layer, or in addition to it, it is preferably provided that the belt loop executes an oscillating movement of the belt or entirely in the vertical direction, so that the contact area of ​​the respective flaps on the outer surface of the belt of the belt loop varies. Due to the oscillation, the contact points of the flaps on the outer surface of the belt of the belt loop constantly change. This increases the service life of the belt of the belt loop because the flaps do not always hit the outer surface of the belt of the belt loop on the same contact line during their movement path. Further advantages, details, and exemplary embodiments are now described with reference to the following drawing. The drawing shows:

[0027] Figure 1: a plan view of the belt loop according to the invention, which is arranged at an angle of inclination with respect to the path of the clips of the clip chain;

[0028] Figure 2: a three-dimensional arrangement of the belt closer according to the invention according to Figure 1;

[0029] Figure 3: a graphic enlargement of the interaction between the belt closer and a flap of a clip of the clip chain, shown compared to Figure 2;

[0030] Figure 4: a three-dimensional detail view of the belt closer according to the invention with a tension roller inside the belt loop of the belt closer;

[0031] Figure 5: a three-dimensional representation of a toothed belt of the belt loop showing the engagement position of the flaps of the clips, the path of movement of the contact of the flaps with the belt loop and the tipping point of the clips;

[0032] Figure 6: a basic three-dimensional view of the entire tilting device according to the invention in the form of the belt closer;

[0033] Figure 7: a flap of the clasp showing the area of ​​the flap which touches the belt strand or the band strand in the path of movement;

[0034] Figure 8a: a plan view of the belt closer arranged at an angle to the track of the clip chain for presetting the distance of the belt from the flaps by means of elongated holes; and

[0035] Figure 8b: Detailed view with eccentric for adjusting the angle of inclination of the belt closer according to the invention by means of a first actuating cylinder. Figure 1 shows a plan view of the tilting device 6 according to the invention in the direction of the clip chain 3, on which flaps 1 of respective clips 2 are drawn. For better understanding, it is shown that the flap 1 of a clip 2 is pivotable, wherein with corresponding interaction of the belt loop 8 according to the invention, the flaps 1 are pivoted from the open position of the clip 2 to the tilting position, whereby the film to be stretched, which lies perpendicular to the plane of the drawing, is clamped in the clamping position. The tilting device 6 is in the form of a belt loop 8, which represents a belt closer and which is arranged obliquely in space with an angle of inclination and a tilt angle.The belt (not specifically identified by a reference number) circulates around the deflection rollers 7 at the respective ends of the belt loop 8, forming a closed, endless loop. Due to the movement of the clip chain 3, which moves at the speed of the film through the stretching system, the flaps 1 of the clips 2 come into tangential contact with the outer side of the belt or the belt of the belt closer, where they are moved from their open position to the tipping point, at which the flap 1 of the clip 2 is pivoted into the clamping position via respective intermediate positions due to the spring action.

[0036] In the middle upper part of Figure 1, a second actuating cylinder 10 is shown which is designed as a hydraulic cylinder and by means of which the entire tilting device 6 can be pivoted from a non-operating position into an operating position and back, for which purpose corresponding levers and stops are provided. After pivoting the belt closer into the operating position, its angle of inclination is adjusted by actuating a first actuating cylinder 16 (see also Figure 6). The set angle of inclination determines the contact length. Before pivoting into the operating position, the tilt angle of the entire tilting device 6 is preset to preferably 7° - 7.5° by means of a stop screw (not shown). With the set angle of inclination, the movement of the flaps 1 and 2 takes place.the clips 2 along the outside of the belt of the belt loop 8 facing the flaps 1, a tilting movement of the flaps 1 up to the tilting point, at which the flap 1 springs into the clamping position in which the film is grasped and clamped at the side edges. This clamping is not released again during the entire passage of the film through the stretching system. With such an arrangement, it is desirable to have the longest possible movement path of the flaps 1 of the clips 2 on the outside of the belt of the belt loop 8, whereby the loads on the clips 2 or flaps 1 are reduced. To avoid friction-related wear of the belt or belt strand, the running speed of the clips 2 and the peripheral speed of the belt strand within the belt loop 8 are synchronized with one another, namely synchronized so that both have the same speed.

[0037] Figure 2 shows the tilting device 6 according to the invention in the form of a belt closer with two deflection rollers 7, wherein the angle of inclination of the belt loop 8 to the running direction of the clip chain 3 with the flaps 1 or clips 2 is shown in a three-dimensional view by the oblique view from above. Again, the flaps 1 in contact with the outside of the belt loop 8 of the belt closer are shown in their contact with the outside of the belt loop 8 within the movement path, caused by the angle of inclination of the belt closer, from the beginning of the contact of the flap 1 with the outside of the belt up to the tilting point at which the flap 1 of the clip 2 springs into the clamping position due to the spring. At the end of the movement path, the contact of the flap 1 with the outside of the belt is terminated.Likewise, this movement path of flap 1 is shown, which occurred before the flap 1 came into contact with the outer side of the belt of the belt loop 8. This illustration clearly shows that the flap 1 of the clamp 2 is pivoted about a pivot axis (not designated in more detail, but shown). Due to the arrangement of the belt loop 8 at an angle of inclination to the track of the clamp chain 3, the flap 1 of the clamp 2 moves continuously during the movement path from the beginning of the contact of the flap 1 with the outer side of the belt of the belt loop 8 to the tipping point, at which the flap 1 springs into the clamping position.

[0038] This, of course, only takes place when the respective flap 1 of the clip 2 has come into contact with the outer side of the belt of the belt loop 8. A deflection roller 7 is designed as a toothed roller in order to transmit drive energy to the belt in the form of a toothed belt without slippage. Also shown in Figure 2 is the arrangement of the tilting device 6 at the inlet area of ​​the film into the stretching system, because from there the film must be clamped by the clips 2. In Figure 3, the conditions shown in Figure 2 are shown in a modified, i.e. lateral, view in three-dimensional manner. Clearly visible is the clip chain 3, which is only shown in principle by means of a complete clip and the associated chain links and a subsequent, only indicated second clip 2. Again, the tilting movement of the flap 1 of the clip 2 is caused by the contact of the flap 1 with the outer side of the belt of the belt loop 8 according to the invention, i.e.the tilting device 6. Also clearly visible is the angle of inclination of the belt loop 8 with respect to the movement path of the clip chain 3 in its running direction, whereby the tilting movement of the clip 1 is initiated in the movement path of the flap 1 on the outside of the belt of the belt loop 8 and is terminated when the tipping point is reached. Using the belt loop 8 according to the invention, a significantly longer movement path can be achieved than that which is possible, for example, using a clip closer wheel, which has already been described in the introduction to the description.

[0039] In Figure 4, according to a further exemplary embodiment, a clip 2 with its corresponding flap 1 is shown as a symbol of the clip chain 3. The tilting device 6 in the form of a belt loop 8 again has deflection rollers 7 at its ends, but has a tensioning wheel 14 arranged inside it in an intermediate region connecting the two deflection rollers 7, which can increase the tension of the band or belt of the belt loop 8 depending on the operating mode or decrease it by moving back into the interior. By adjusting the tension of the belt or band of the belt closer or the belt loop 8, the belt tension can be adjusted accordingly, so that the impact points of the respective flaps 1 are, if necessary, gentler without the need to change the angle of inclination of the belt closer.The tangential impact angle of the flaps 1 on the outside of the belt approaches zero, allowing the flaps to impact the belt even more gently. The basic structure corresponds to that shown in Figures 1 to 3.

[0040] Figure 5 shows a three-dimensional detail of a toothed belt 13 as a band of the belt loop 8 according to the invention. Shown is a section of the belt loop 8 with four flaps 1 of the respective clips 2 of the clip chain 3 in conjunction with their engagement with the outer side of the toothed belt 13, which forms the band of the belt loop 8 according to the invention. In the left section of the toothed belt 13 of the belt loop 8, the smaller double arrow indicates the area in which the flaps 1 of the clips 2 do not yet touch the outer side of the toothed belt. At the end of the section marked by the small double arrow, the larger and longer double arrow begins, at the left end of which the left middle flap 1 is just touching the outer side of the toothed belt. This represents the start of the contact and thus the left end of the contact length 9.The right middle flap 1 of the clamp 2, shown in the right third of Figure 5, is in contact with the outside of the toothed belt 13 and has just covered the middle length of its travel path with uninterrupted contact with the outside of the toothed belt 13. At the right end of the larger double arrow, which represents the contact path of the flaps 1 on the outside of the toothed belt 13, the right flap 1 then located there is pressed so far in the direction of the clamping position that, as a result of the spring in the clamp 2, upon reaching the tipping point, which is at the right end of the larger double arrow, it is tilted from the still open position into the closed, i.e. clamping, position. In the illustrated embodiment, the start-up path, during which there is still no contact between the flap 1 and the outside of the toothed belt 13, is approximately 50 mm long.In this example, the movement path of flap 1 with corresponding contact on the outside of the toothed belt 13 up to the tipping point is 200 mm as the length of contact of flap 1 on the outside of the toothed belt 13.

[0041] It can also be seen that the toothed belt 13 of the belt loop 8, i.e. the belt loop as a whole, is inclined in its alignment to the running direction of the clip chain 3, so that in the course of the movement of the flaps 1 of the clips 2 along the path of movement, these are inclined more and more, starting from the first contact on the outside of the toothed belt 13 up to the tipping point, so that ultimately at the tipping point, due to the effect of the spring built into the clip 2, the flap 1 tilts into the clamping position and the film in the film system is clamped on its side.

[0042] Figure 6 shows a three-dimensional view of the entire tilting device 6 in the form of a belt loop 8 of the belt closer according to the invention. The essential elements are the belt loop 8, by means of which the actual tilting process of the flaps 1 into their clamped position is realized, the drive unit 17, which drives the circulating belt via deflection rollers 7, the second actuating cylinder 10, by means of which the entire tilting device 6 pivots from the non-operating position into the operating position, the first actuating cylinder 16, by means of which the angle of inclination of the belt closer is adjusted, and the eccentric 11, by means of which the angle of inclination between the clamp chain and the belt loop is preset.

[0043] Figure 7 shows a flap 1 of the clamp 2 (not shown), in which the area of ​​the upper end of the flap 1 is marked with a square, which indicates the contact area 15 of the flap 1 on the belt strand. This clearly shows that only the upper area of ​​the flap 1 rests on the belt strand or on the outer side of the belt of the belt loop 8 during the movement path of the flap 1. The friction conditions between this upper part of the flap 1 and the outer side of the belt of the belt loop 8 are ultimately limited to the contact area 15 of the flap 1.

[0044] Figure 8a shows a top view of the belt closer arranged at an angle to the track of the clip chain 3. The belt closer features elongated holes 12 arranged transversely to the running direction of the film to be stretched in the system. The belt loop 8, also referred to as a clip closer or belt closer, is preset in the operating position via the elongated holes 12 and with regard to the distance of the belt from the flaps 1.

[0045] The length ratios of the belt closer are now selected such that the flap 1 only touches the outside of the belt of the belt loop 8 or the belt strand approximately 50 mm after the lower deflection roller 7 shown in the drawing. This contact-free section is represented by a lower short double arrow. The middle longer double arrow represents the area within which the flaps 1 touch the outside of the belt of the belt loop 8 over the entire contact path or over the entire contact length 9, i.e., are carried or run along. After reaching the tipping point, which lies at the upper end of the large double arrow representing the contact path 9, the corresponding clips 2 are clamped to the film to be stretched by the spring action within the clips 2. By adjusting the elongated holes 12, the start of the contact of the flaps 1 on the outside of the belt of the belt loop 8 can be varied, i.e.Ultimately, the contact length 9 can also be influenced. Finally, Figure 8b shows a detailed view with an eccentric 11 for adjusting the angle of inclination between flaps 1 and belt loop 8, and thus also for adjusting the contact length 9, as well as the first actuating cylinder 16. Figure 8b shows that the entire tilting device 6 has been pivoted into its operating position by means of the second actuating cylinder 10, in which position it can be adjusted to the desired angle of inclination by means of the first actuating cylinder 16. The eccentric 11 can be used to adjust the angle of inclination of the belt loop 8 with respect to the running direction of the clip chain 3, and thus the beginning of its contact on the outside of the belt strand. An adjustment scale 18 serves to visualize the set angle of inclination of the tilting device 6.

[0046] List of reference symbols

[0047] 1 flap

[0048] 2 cleats

[0049] 3 clip chain

[0050] 4 Open position

[0051] 5 Closing position

[0052] 6 Tilting device

[0053] 7 pulleys

[0054] 8 Belt loop / belt closer

[0055] 9 Contact length

[0056] 10 second actuating cylinder

[0057] 11 eccentric

[0058] 12 elongated holes

[0059] 13 Timing belt

[0060] 14 Tensioning wheel

[0061] 15 Contact area flap on belt strand

[0062] 16 first actuating cylinder

[0063] 17 Drive unit

[0064] 18 Setting scale

Claims

PATENT CLAIMS 1. Device for actuating clips (2) of a film stretching system, said clips having flaps (1) running at a speed of movement of a clip chain (3), from an open position (4) not clamping a film into a closed position (5) clamping the film, wherein the flaps (1) collide with a tilting device (6) as they pass by, which is arranged in the path of the clips (2) in the region of the film running into the film stretching system, wherein the tilting device (6) tilting the flaps (1) is designed as a belt loop (8) arranged at an oblique angle in space, guided by deflection rollers (7), rotating at a rotational speed, and the rotational speed of the belt loop (8) is synchronized with the movement speed of the clips (2), characterized in thatthat during the collision of the flaps (1) with the belt loop (8), these run along the outside of the belt loop (8) and, after a set movement path, are pressed from the open position (4) towards the closed position (5) until they exceed their tipping point, and the movement speed of the clip chain (3) is 500 m / min to 750 m / min., 2. Device according to claim 1, characterized in that the flaps (1) collide with the belt loop (8) at such an acute angle that the flaps (1) run smoothly onto the belt loop (8) at least at their points of impact.

3. Device according to claim 1 or 2, characterized in that the flaps (1) run along the belt loop (8) via the contact length (9) which can be adjusted via an angle of inclination of the tilting device (6) to the travel path of the flaps (1).

4. Device according to claim 3, characterized in that the contact length (9) is adjustable by means of a first adjusting cylinder (16) via an eccentric (11) for adjusting the spatial position of the tilting device (6).

5. Device according to claim 3, characterized in that the contact length (9) is adjustable by means of displacement of the tilting device (6) via elongated holes (12). Device according to one of claims 3 to 5, characterized in that the contact length (9) of the flaps (1) on the belt loop (8) is 120 to 250 mm, in particular 150 to 200 mm, in particular 120 to 150 mm. Device according to one of claims 1 to 6, characterized in that the belt loop (8) has a length reserve which compensates for deviations in the impact points of the flaps (1) on the belt loop (8) that exist between the individual flaps (1) of the clips (2). Device according to one of claims 1 to 7, characterized in that the flaps (1) of the clips (2) are made of non-ferromagnetic material. Device according to one of claims 1 to 8, characterized in that the flaps (1) of the clips (2) are designed as single flaps or double flaps.Device according to one of claims 1 to 9, characterized in that the tilting device (6) can be pivoted completely away from its position in collision with the flaps (1) by means of a second actuating cylinder (10). Device according to one of claims 1 to 10, characterized in that the tilting device (6) is a toothed belt (13). Device according to one of claims 1 to 10, characterized in that the tilting device (6) is a flat belt or a chain. Device according to one of claims 1 to 12, characterized in that the tilting device (6), designed as a belt loop (8), is driven by a drive unit (17), in particular by a servomotor, which is synchronized with the speed of the clip chain (3) via a controller.Device according to one of claims 1 to 13, characterized in that the tilting device (6) has a wear-resistant layer which is arranged on its side facing the flaps (1).

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