Device and method for wrapping pallets

Abstract

The invention relates to a rotary-arm winding system for wrapping pallets (P) loaded with articles with a film which can be pulled off a film reel (F). The rotary-arm winding system comprises a changing device (2) for automatically changing the film reel (F). The rotary-arm winding system has at least one supporting frame with a winding arm (4) which is arranged rotatably thereon and has an unwinding unit (5), wherein the unwinding unit of the rotatable winding arm has at least one reel chuck (6) for holding the film reel (F) in a supporting manner and at least one roller arrangement (7) for guiding the film during winding. The changing device has at least one carriage (11) which can be moved in a feed direction (8) between a loading region (9) and a changing region (10), wherein the movable carriage has at least one first reel holder (12) for holding an empty film reel (F) and at least one second reel holder (13) for holding a full film reel (F). Furthermore, the movable carriage has a movably arranged guide unit (14) for guiding the film. Provided on the movable carriage is a clip arm (15) which is arranged movably in the feed direction and has a retaining clip (16), fastened on the free end side, for retaining a film end, and the changing device also has a receiving and fixing unit (17).

Description

[0001] Device and method for wrapping pallets

[0002] The invention relates to a device or a system for wrapping pallets loaded with articles with a film, in particular to a rotary arm wrapping device or a rotary arm wrapping system for wrapping pallets with stretch film. Furthermore, the invention also relates to a method for wrapping pallets loaded with articles with a film.

[0003] Devices for wrapping pallets, which are generally also referred to as film wrapping machines, film wrappers, or pallet wrapping machines or pallet wrappers, are known in a wide variety of designs and are used in particular for wrapping loaded pallets in order to secure the load on the pallet. The film is usually provided as a film web wound on a roll or spool, namely in the form of a film reel or film roll, or as a wound roll. During the wrapping process, the film is pulled from the roll or spool by the film wrapping machine and wrapped around the pallet.

[0004] In contrast to so-called turntable machines, in which the loaded pallet rotates on a turntable during the wrapping process, film wrapping machines of the type concerned by the invention are essentially rotor machines, in particular rotary arm wrapping machines with a rotating rotary arm or wrapping arm designed as a rotor element. In these rotary arm wrapping machines, the loaded pallet, which is at least temporarily stationary, is encircled by the rotary arm for wrapping with film and is thereby wrapped with film.

[0005] For this purpose, the rotating arm carries an unwinding unit, which usually has a holder for holding the film spool or reel, this holder is also referred to as a spool or reel chuck or spool or reel holder, as well as several interacting rollers over which the film can be pulled off and applied to the pallet while maintaining a predetermined film tension. With these known devices and systems, the film spools must be changed when the film is pulled off and used up. This means that the emptied spool must be replaced or exchanged with a new, full film spool. This exchange is generally carried out manually by one or more operators. For this purpose, the device must be switched from normal operation to a changeover state and stopped so that the device or system is at a standstill for the duration of the change.

[0006] Since, when changing the film reel, it is necessary to detach a free end of the film web from the film reel and to pull off a beginning of the film web in order to guide and keep this web beginning in the rollers of the unwinding unit in the desired and required manner, the changing process is time-consuming and labor-intensive and requires long downtimes of the device, so that there are efforts to facilitate and improve the changing of the film reels.

[0007] However, previous attempts at improvement have proven to be very difficult, particularly in rotary arm winding systems, since inserting or threading the beginning of the film web and fixing the end of the film is difficult with rotating rotary arms.

[0008] The object of the invention is therefore to provide a rotary arm winding system that allows a reliable and safe changing of film reels with reduced time and effort and, in particular, with the shortest possible downtime of the system.

[0009] This object is achieved by a rotary arm wrapping system according to the features of independent patent claim 1. Furthermore, a method according to the features of independent patent claim 16 is proposed to achieve the object. The subclaims relate to particularly advantageous developments of the invention. The present invention provides a rotary arm wrapping system for wrapping pallets loaded with articles with a film that can be pulled off a film reel. According to the invention, the rotary arm wrapping system has a changing device for automatically changing the film reel. The rotary arm wrapping system comprises at least one support frame with a winding arm rotatably arranged thereon, having an unwinding unit that has at least one reel chuck for supporting the film reel and at least one roller arrangement for guiding the film during wrapping.The changing device of the rotary arm winding system has at least one carriage movable in a feed direction between a loading area and a changing area, which carriage has at least one first reel holder for receiving an empty film reel and at least one second reel holder for receiving a full film reel. The movable carriage further has a movably arranged guide unit for guiding the film. A clamp arm, which is movably arranged in the feed direction and has a holding clamp attached to the free end for holding a film end, is provided on the movable carriage. The changing device further has a takeover and fixing unit, which is designed to take over and fix the film end from the holding clamp and has a clamping device, which can be controlled between an open and closed position, for clamping the film end from the holding clamp.

[0010] The rotary arm winding system according to the invention can also be referred to here as a rotary arm winding device or rotary arm winding machine and is designed as a rotor machine, wherein the rotating winding arm or rotary arm forming a rotor element is mounted so as to be rotatable about a vertical axis of rotation or rotation, such that it orbits a pallet for wrapping. The winding arm comprises, in a known manner, a horizontally extending arm section, via which the winding arm is rotatably attached to the support frame. A vertically extending arm section adjoins this horizontally extending arm section essentially at a right angle and provides a free end for receiving the unwinding unit.The rotary arm winding system can, for example, be designed with one arm or two arms, and can, for example, have exactly one vertically extending arm section or two vertically extending arm sections opposite one another with respect to the horizontally extending arm section.

[0011] The unwinding unit provided at the free end of the winding arm is arranged on the vertically extending arm section of the winding arm so that it can be lifted and lowered and can be moved in the vertical direction, i.e. in the direction of the rotational axis of the winding arm, by means of a provided drive. The unwinding unit with the roller arrangement is designed in a manner known to those skilled in the art. The roller arrangement for guiding the film during winding can also be referred to here as a roller arrangement or spindle arrangement and is designed in the present sense both for guiding and, in particular, for pulling off the film, for stretching, tensioning and the like. For this purpose, the roller or roller arrangement comprises several interacting rollers or rollers, including, for example, pre-stretching and / or idle rollers, tensioning rollers, unwinding rollers and the like.

[0012] In the operating position of the rotary arm winding system, namely in the ready-to-use state, in particular in the ready-to-use state of the unwinding unit of the winding arm, the film web to be pulled off or pulled off the film reel is guided in a predetermined, specific manner between the rollers or cylinders of the roller arrangement, in particular "threaded" in a defined course between the rollers or cylinders.

[0013] In the changeover state or in the changeover position, the unwinding unit, in particular the roll arrangement for receiving a new, full film reel, is moved vertically downwards into the changeover position, wherein in this stage the film web is transferred or transferred to the roll arrangement in the predetermined, defined guided manner.

[0014] According to the invention, the film reel can be changed automatically, in particular fully automatically, thanks to the provided changing device, with manual intervention by an operator being reduced to a minimum. Thus, the present rotary arm winding system enables a film reel to be replaced with minimal manual intervention and in a relatively short time.

[0015] Further advantages arise in the rotary arm winding system according to the invention due to the provided changing device in that such, in particular all, preparatory steps to be carried out manually by an operator when preparing the film reel can be carried out outside the working area of ​​the winding arm.

[0016] For this purpose, the changing device has a loading area located outside the working area of ​​the winding arm. The movable carriage of the changing device is positioned in the loading area during normal operation, or during the working operation of the winding arm, and can be prepared for a later changeover process for inserting a new, full film reel by placing a new film reel onto the second reel holder of the movable carriage in the loading area.

[0017] The loading area is therefore located outside the machine room of the wrapping arm and away from the transport devices for feeding and removing the pallets to be wrapped. It is insulated and located outside of an enclosure or protective space of the rotating arm so that the loading area is safely accessible to an operator. For example, the loading area can be accommodated in its own protective housing. In this case, the loading area can also be understood as the home position, starting position, base position or zero position of the movable carriage and thus forms a so-called “home position” for the movable carriage, in which the movable carriage is located during normal operation of the rotating arm wrapping system. Only in alternating operation orIn the changeover state, the movable carriage is moved out of its home position and in the feed direction towards the take-over and fixing unit, where the changeover area is located, in particular adjacent to the take-over and fixing unit. The feed direction extends essentially perpendicular to a basic transport direction of the pallets to be wrapped. In preparation for an upcoming changeover process, the operator can advantageously carry out all the necessary steps to prepare the new, full film spool in the loading area and thus in the home position of the movable carriage, which is away from the machine room of the wrapping arm. After placing a full film spool on the second spool holder of the carriage, the operator can remove the film end, namely the edge or end of the wound film.Detach the film web from the film reel, thus providing a beginning or web start for pulling the film from the film reel. The pulled-off web start can be manually placed or guided around the guide unit provided on the movable carriage, in particular "threaded" into it, by the operator in a predetermined, defined manner. The film end, which can also be understood as the free end of the film, can be temporarily secured by inserting it into the retaining clamp of the clamp arm movably mounted on the carriage.

[0018] At the time of inserting and temporarily securing the free film end in the holding clamp attached to the free end of the clamp arm, the movable clamp arm is preferably positioned in its retracted home or starting position. In this retracted state, the clamp arm is retracted to the side of the movable carriage remote from or opposite the transfer and securing unit. The new, full film reel is ready in this position for an upcoming changeover process.

[0019] In changeover operation or changeover state, the movable carriage is moved out of the loading area, towards the take-over and fixing unit in the changeover area and an empty film spool is replaced by a full film spool in the unwinding unit of the winding arm. In the present understanding, an “empty film spool” is the used or emptied, i.e. “old” spool to be replaced, which is ejected or released from the spool chuck of the unwinding unit. The “full film spool”, on the other hand, is a new or fresh film spool that is to be made available and inserted or fed into the unwinding unit. During the changeover, the empty film spool ejected or released from the spool chuck of the unwinding unit is first transferred to or pushed onto the first spool holder of the movable carriage located in the changeover area.Conversely, the full film reel prepared in the loading area and placed by an operator on the second reel holder is then transferred from the second reel holder to the reel chuck of the unwinding unit or pushed onto it.

[0020] When the full film reel is transferred from the movable carriage to the unwinding unit of the winding arm, the removed web lead, guided in the guide unit of the movable carriage, is transferred or transferred to the rollers or cylinders of the roll arrangement of the unwinding unit while maintaining the "threaded" configuration, so that the removed web lead is guided or "threaded" in the specified manner in the roll arrangement of the unwinding unit. The film end is moved further in the feed direction toward the take-over and fixing unit by extending the clamping arm, thereby feeding it to the take-over and fixing unit. The extension of the clamping arm can therefore also be understood as a feed movement.

[0021] When the clamping arm is extended or in the feed position, it projects beyond the movable carriage on the side facing the transfer and fixing unit, so that in this position of the clamping arm the clamping device of the transfer and fixing unit can safely take over the end of the film from the holding clamp of the clamping arm arranged on the carriage.

[0022] In addition to the advantages of the rotary arm winding system according to the invention already mentioned above, namely that a film reel can be replaced with minimal manual intervention and short operating times and that changing the film reels is particularly safe for the operating personnel, further advantages of the rotary arm winding system according to the invention arise from the fact that the changing process is particularly precise and the downtime of the rotary arm winding system required for the change is reduced to a minimum. The precision of the changing process results in particular from the inventive design of the changing device and its interacting components, in particular the holding clamp interacting with the clamping device, specifically when transferring the film end temporarily fixed in the holding clamp on the movable carriage to the clamping device of the transfer and fixing unit.In alternating operation, i.e., when the movable carriage is positioned in the changing area and its clamp arm is in the extended feed position, the holding clamp and the stationary transfer and fixing unit are always aligned relative to each other in the required, correct position, in which the transfer of the film end can take place effectively, smoothly, and safely. The secure, always precise positioning of the holding clamp relative to the transfer and fixing unit is independent of the exact positioning, in particular the rotational position, of the winding arm. Due to the exact relative positioning of the holding clamp relative to the transfer and fixing unit, the transfer of the film end always takes place in the same configuration.The end of the film reel transferred to the unwinding unit and located on the reel chuck can thus be taken over and fixed effectively, safely and quickly by the clamping device without the need to set an exact rotational position of the winding arm.

[0023] According to a preferred embodiment of the present invention, the changing device further comprises a carriage guide for the guided movement of the movable carriage, wherein the movable carriage can be moved in a guided manner between the loading area and the changing area by means of the carriage guide. The carriage guide, which in the present case can also be understood as a track or guideway or as a transport track for the carriage, has a longitudinal extent in the direction of the feed direction and thus extends along its length essentially perpendicular to a basic transport direction during the feeding and removal or during the transport to and from of the pallets to be wrapped. Preferably, the changing device further comprises a drive, in particular a motor drive, for driving the movable carriage. For example, this can be an electric motor drive or an electromagnetic drive or the like.

[0024] Particularly preferably, at least one first position that can be assumed by the movable carriage and at least one second position that can be assumed by the movable carriage are provided within the changing area. In this case, the movable carriage can be positioned in a fixed position, in particular in each of the two positions. By means of these two positions, in which the movable carriage can be held exactly and precisely fixed, the changing process can be carried out in a particularly safe and trouble-free manner. The assumption and maintenance of the two positions is carried out in a particularly controlled and / or regulated manner by means of a control and / or regulating unit that is connected in a communicating manner, for example, to the motor drive, and can be additionally secured, for example, with appropriately suitable locking and / or securing means.

[0025] Particularly preferably, the movable carriage is positioned in the first position relative to the reel chuck of the unwinding unit of the rotatable winding arm in such a way that the empty film reel can be transferred from the reel chuck to the first reel receptacle of the movable carriage, in particular such that the empty film reel ejected from the reel chuck can be pushed or transferred directly and immediately from the reel chuck to the first reel receptacle. The elongated first reel receptacle, designed as a mandrel or spindle or pin or bolt, and extending substantially vertically along its length, in particular parallel to the rotational or turning axis of the winding arm, is arranged in this first position of the movable carriage substantially coaxially with the likewise elongated reel chuck, which extends substantially vertically along its length, in particular parallel to the rotational or turning axis of the winding arm.

[0026] Furthermore, the movable carriage is preferably positioned in the second position relative to the reel chuck of the unwinding unit of the rotatable winding arm in such a way that the full film reel can be transferred from the second reel holder of the movable carriage to the reel chuck, in particular such that the film reel can be pushed or transferred directly and immediately from the second reel holder onto the reel chuck. The second reel holder, which is also designed as a mandrel or spindle or pin or bolt, is elongated and extends lengthwise essentially vertically, in particular parallel to the rotational axis of the winding arm, and is arranged essentially coaxially to the reel chuck in this second position of the movable carriage.

[0027] Particular advantages also arise from the fact that the guide unit arranged on the movable carriage for guiding the film is designed to be liftable and lowerable. In particular, the guide unit can be retracted into a carriage housing of the movable carriage, preferably in such a way that the guide unit can be lowered into an upper side of the carriage extending along a horizontal plane. When the unwinding unit is positioned for the changing process, namely in its lowered state when it is brought into engagement with the movable carriage, the guide unit can be lowered into the carriage housing if or as soon as the roller arrangement of the unwinding unit has come into engagement or contact with the guide unit. By lowering the guide unit, the beginning of the film web guided on it is transferred to the rollers or cylinders of the roller arrangement and continues to be guided and held by them.

[0028] In this preferred embodiment, the drawn-off web beginning guided in the guide unit of the movable carriage can be transferred or transferred to the rollers or cylinders of the roller arrangement of the unwinding unit particularly easily, quickly, safely, smoothly and unhindered while maintaining the "threaded" configuration, in particular while safely maintaining the "threaded" configuration.

[0029] Furthermore, recesses are advantageously provided in the carriage housing on the top side of the carriage for engagement of the roller assembly, in particular for immersing engagement of the rollers or cylinders of the roller assembly into the housing. In this way, by lowering the guide unit of the movable carriage, the film can be transferred to the roller assembly of the unwinding unit of the rotatable winding arm, in particular to a respective defined roller section or cylinder section of the rollers or cylinders, which roller section has at least a predetermined distance from the respective free ends of the rollers or cylinders, thereby further increasing the reliability of the transfer.

[0030] Particular advantages also arise from the fact that the guide unit has a plurality of guide surfaces for guiding the film, wherein the guide surfaces are arranged in particular so as to be countersunk in the recesses on the upper side of the carriage and are designed to correspond to the roller arrangement, in particular to the rollers of the roller arrangement. The film preferably lies against the guide surfaces. A configuration “corresponding to the roller arrangement” is understood here to mean that the guide surfaces of the guide unit are designed such that they provide respective, in particular curved, contact surfaces on the side opposite the guide surface for the film to rest on, which contact surfaces at least in sections come into contact with the rollers of the roller arrangement and bear against them, in particular in sections on the circumference of the respective rollers. The guide surfaces orThe contact surfaces thus, in the broadest sense, at least partially describe the contours of the rollers of the roller assembly. The guide surfaces are particularly preferably designed as curved guide plates that can be retracted synchronously.

[0031] According to a preferred embodiment of the invention, the holding clamp arranged on the movable clamp arm of the movable carriage, which is intended to temporarily hold the film end of a film reel to be prepared, has two elongated clamp bolts arranged parallel to one another, each extending horizontally in the longitudinal direction, in particular perpendicular to the feed direction. The clamp bolts, which can also be referred to as clamp pins in this case, are perpendicular to the feed direction and thus parallel to the general transport direction of the pallets and parallel to the axial direction of a main axis of the transfer and fixing unit away from the clamp arm. In this way, the film end can be transferred to the clamping device particularly securely and without obstruction.

[0032] Particularly preferably, the two clamping bolts are arranged in superimposed horizontal planes and, in particular, form a lower and an upper clamping bolt, with both clamping bolts being arranged in a common vertical plane running perpendicular to the superimposed horizontal planes. This facilitates, on the one hand, the temporary fixation of the film end in the retaining clamp and, on the other hand, also makes it easier for the clamping device to take over the film end.

[0033] Particularly advantageously, the clamping device, which can be adjusted in a controlled manner between the open and closed positions, comprises two elongated clamping elements, which can also be understood as clamping jaws. At least one of the two clamping elements, preferably both clamping elements, is / are designed to be pivotable about a respective pivot axis, wherein the respective pivot axis extends in particular substantially parallel to the feed direction and perpendicular to the main axis of the transfer and fixing unit. In this embodiment, the clamping elements are adjusted between the open and closed positions in a controlled manner by pivoting. To assume the closed position, the clamping elements are moved towards one another or brought together by pivoting. To return from the closed position to the open position, the clamping elements are moved away from one another or moved apart by pivoting.

[0034] In the closed position of the clamping device, both clamping elements preferably extend vertically along their respective lengths and, in particular, protrude beyond the transfer and fixing unit at the top. In this configuration, the fixed film end can be held securely and reliably in the specified and desired manner and, in particular, for the specified and desired or required period of time. Most preferably, at least one of the clamping elements, preferably both clamping elements, can be pivoted into a horizontal orientation over a respective pivot angle range of approximately 90° and can thus be retracted into the transfer and fixing unit. In this way, the clamping elements can be retracted below a working level during normal operation of the rotary arm winding system and do not represent any spatial obstruction or disruption to the rotating winding arm.

[0035] The present invention also relates to a method for automatically changing film reels in a rotary arm winding system according to one of the preceding claims. The key advantages of the method have already been described above in connection with the rotary arm winding system, as well as a basic process sequence, so reference can be made here to the description of the rotary arm winding system.

[0036] The invention is explained in more detail below with reference to exemplary embodiments and the figures. They show:

[0037] Fig. 1 is a simplified and schematic partial representation of a

[0038] Embodiment of a rotary arm winding system in a perspective view (wherein only parts or components of the rotary arm winding system relevant to the present invention are shown);

[0039] Fig. 2 simplified and schematically shown in more detail a

[0040] Detail of Figure 1 ;

[0041] Fig. 2a shows an enlarged section of Figure 2 in the area of ​​a

[0042] clamp arm;

[0043] Fig. 3 shows a simplified and schematic perspective

[0044] View of the changing device of the rotary arm winding system with the housing partially removed and Fig. 4a and 4b show a simplified and schematic perspective, top-side partial view of an embodiment of the movable carriage with a guide unit provided on the top side of the carriage, which is recessed in the carriage housing in Fig. 4b and is therefore only visible in Fig. 4a.

[0045] Identical reference numerals are used in the figures for identical or equivalently functioning elements of the invention. Furthermore, for the sake of clarity, only those reference numerals are shown in the individual figures that are necessary for the description of the respective figure. Furthermore, the invention is shown in the figures only as a schematic view to explain its operation. In particular, the representations in the figures serve only to explain the basic principle of the invention. For reasons of clarity, all components of the present system have been omitted.

[0046] Figure 1 shows a simplified and schematic partial representation of an embodiment of a rotary arm winding system 1 in a perspective view. In particular, only those parts or components of the rotary arm winding system 1 are shown and specified in the figure that are relevant in connection with the explanation of the present invention. It is understood that the rotary arm winding system 1 comprises further components that have been omitted solely for the sake of simplicity.

[0047] The rotary arm wrapping system 1 is essentially designed as a rotating wrapping device with a wrapping arm 4 that is rotatably arranged on a support frame 3 or can be driven about a vertical axis of rotation or axis of rotation RA, and is used to wrap pallets P loaded with articles with a film that is pulled off a film reel F while the pallet P is being wrapped. The film for wrapping is, for example, an extensible film made of a plastic material, in particular a so-called stretch film, which is wrapped around the pallet P with a predetermined tension in order to thereby stabilize the articles on the pallet.The pallets P loaded with articles are, for example, pallets P with multiple layers of containers assembled and / or grouped in a respective layer arrangement, in particular containers filled with beverages, such as cans, bottles, or the like. Within a respective layer, the containers can be loose or in container bundles. The present rotary arm wrapping system 1 can thus be understood as part or component of a packaging system, particularly in the beverage industry, and as such forms a packaging machine.

[0048] The loaded pallets P are conveyed into and removed from a working area of ​​the rotary arm wrapping system 1 for wrapping by means of a dedicated transport or conveyor device, for example, a belt conveyor such as a roller belt or chain belt, in a general transport direction TR or conveying direction. In the working area, in particular in a space within the support frame 3, the pallet P remains stationary during wrapping and is encircled by the rotating wrapping arm 4 for wrapping with the film.

[0049] The rotating wrapping arm 4 is rotatably mounted with a horizontally extending arm section on an upper side of the support frame 3, in particular on a horizontal support strut, and points vertically downwards with a vertically extending arm section having a free end and adjoining the horizontally extending arm section at a right angle. An unwinding unit 5, which is vertically movable in height in the vertical direction, is arranged on the vertically extending arm section of the rotating wrapping arm 4. A film reel F is carried over said unwinding unit and, when wrapping the pallet P, pulls the film from the film reel F and applies it to the pallet P.

[0050] The unwinding unit 5 of the rotating winding arm 4 has at least one reel chuck 6 for supporting the film reel F and at least one reel assembly 7 equipped with a plurality of rollers or cylinders for guiding the film during winding. The unwinding unit 5 with the reel assembly 7 can, for example, be designed in a manner known to those skilled in the art. The present rotating arm winding system 1 has a changing device 2 for automatically changing the film reel F, so that an empty film reel F can be replaced with a new, full film reel F in a short time, with the shortest possible downtime of the rotating arm winding system 1 and with minimal manual effort.

[0051] The changing device 2 comprises a movable carriage 11, which can be moved towards the winding arm 4 or to its working area and away from it again in order to deliver a full film reel F there and in turn discharge an empty film reel F. The movable carriage 11 can be moved in a feed direction 8 between a loading area 9 and a changing area 10. The loading area 9, which can also be understood as the "home position" of the carriage 11, lies outside the working area of ​​the winding arm 4 and is therefore safely accessible to an operator for manually loading the carriage 11 with a new, full film reel F. The changing area 10, on the other hand, lies within the working area of ​​the winding arm 4, but does not require access by an operator, since all processes for changing the film reel F that take place within the changing area 10 are carried out automatically, in particular fully automatically.be performed.

[0052] In the example shown, the movable carriage 11 can be guided along a carriage guide 19 which extends lengthwise in the feed direction 8 and perpendicular to the transport direction TR and is driven in a controlled manner by a motor drive 22 (not visible in Figure 1, see Figure 3). The movable carriage 11 carries at least one essentially pin-, stud-, or bolt-shaped first spool holder 12 for supporting and holding an empty film spool F to be discharged, as well as at least one likewise essentially pin-, stud-, or bolt-shaped second spool holder 13 for supporting and holding a new, full film spool F to be inserted or made available. When loading the carriage 11 with a new, full film spool F, that is to say after placing a full film spool F on the second spool holder 13 of the carriage 11, the operator can cut the film end, namely the edge ordetach the end of the wound film or film web from the film reel F and thus provide a beginning or web start for pulling the film off the film reel F. The pulled-off web start can be placed or guided manually by the operator in a predetermined, defined manner around a guide unit 14 provided on the movable carriage 11, in particular "threaded" into it.

[0053] In the example shown, the movably arranged guide unit 14 is provided on a carriage upper side 11a and is designed to be movable in lifting / lowering directions and can be retracted into a carriage housing 21 of the movable carriage 11, in particular in such a way that the guide unit 14 can be lowered into the carriage housing 21 in the carriage upper side 11a extending along a horizontal plane, as is illustrated in Figures 4a and 4b.

[0054] The exemplary guide unit 14 has a plurality of guide surfaces 14', each designed as curved guide plates, which are arranged or received in corresponding recesses 20 or through openings in the carriage housing 21 on the carriage top side 11a and can be lowered synchronously in a controlled manner. A pneumatic cylinder 23 is provided for the lifting and lowering movement of the guide unit 14, in particular the guide plates.

[0055] The recesses 20 or through openings in the carriage housing 21 and in particular the shape and geometry of the guide surfaces 14' are such that the guide surfaces 14' are designed and arranged to correspond to the roller arrangement 7 of the unwinding unit 5, so that during the changeover process in the changeover area, the rollers of the roller arrangement 7 engage in the recesses 20 in the carriage housing 21 and can immerse themselves over a predetermined immersion path and, in the process, come into contact with the guide plates in such a way that the guide plates partially surround the rollers and bear against them. The contact surfaces or contact surfaces of the guide plates are opposite the surfaces against which the film rests and is guided, so that when the guide plates 14 are drawn in, namely sunk, in the carriage housing 21, the film guided on the guide plates 14 transfers to the rollers of the roller arrangement 7 orand is then held and guided by the rollers of roller arrangement 7 in the specified configuration.

[0056] The film end, which is released by the operator when the new, full film reel F is provided in the loading area 9 and which can also be understood as the free end of the film, is temporarily fixed by appropriate insertion into a holding clamp 16 of a clamp arm 15 movably arranged on the carriage 11 and is transferred to a clamping device 18 of a transfer and fixing unit 17 during the change process in the change area 10.

[0057] For this purpose, the movable clamp arm 15, equipped with the holding clamp 16 on the free end, is provided on the movable carriage 11 of the changing device 2 and can be extended in the feed direction 8. When loading the carriage 11 with a new, full film reel F, the film end is inserted into the holding clamp 16 in such a way that it is temporarily fixed until it is transferred to the clamping device 18. A pneumatic cylinder, for example, is provided for moving the clamp arm 15.

[0058] As can be seen in particular from Figure 2a, the holding clamp 16 of the movable clamp arm 15 has two elongated clamp bolts 16.1, 16.2 arranged parallel to one another, which each extend horizontally in the longitudinal direction and perpendicular to the feed direction 8. The two clamp bolts 16.1, 16.2 are arranged in superimposed horizontal planes E1, E2 and form a lower clamp bolt 16.2 and an upper clamp bolt 16.1, wherein both clamp bolts 16.1, 16.2 are arranged in a common vertical plane running perpendicular to the superimposed horizontal planes E1, E2. The transfer and fixing unit 17 of the changing device 2 is arranged in a stationary manner and extends lengthwise along a main axis HA, which runs perpendicular to the feed direction 8.The transfer and fixing unit 17 is designed to transfer and fix the film end from the holding clamp 16 and, for this purpose, has a clamping device 18 that can be adjusted between an open and closed position in a controlled manner for clamping the film end from the holding clamp 16. In the figures, the clamping device 18 is shown in its closed position, in which it can clamp the film end.

[0059] In the example shown, the clamping device 18 comprises two elongated clamping elements which can be pivoted about a respective pivot axis and which can also be understood as clamping jaws. The pivot axes run perpendicular to the main axis HA of the transfer and fixing unit 17 and parallel to the feed direction 8. In the closed position of the clamping device 18, both clamping elements extend vertically in their respective longitudinal direction and protrude above the transfer and fixing unit 17. The clamping elements can be moved relative to one another by means of respective pivoting movements S1, S2 and can be pivoted into a horizontal orientation over a respective pivot angle range of approximately 90°, so that each of the clamping elements can be retractably received in the transfer and fixing unit 17.

[0060] To take over the film end from the holding clamp 16 of the carriage 11, during the changing process, the carriage 11 is first moved to the takeover and fixing unit 17 in the changing area 10, specifically into a second position in the changing area 10, in which the carriage 11 is positioned relative to the spool chuck 6 of the unwinding unit 5 of the rotatable winding arm 4 such that the full film spool F can be transferred from the second spool holder 13 of the movable carriage 11 onto the spool chuck 6. Upon reaching this second position, the clamping arm 15 is extended further in the feed direction 8 and the film end temporarily fixed in the holding clamp 16 is fed to the clamping device 18. At this stage, one of the clamping elements has already been pivoted into its vertical orientation and is thus in a waiting position.The second clamping element, still in a lowered, horizontal position, is pivoted with the clamping arm 15 extended, so that the clamping device 18 is brought into the closed position. During this pivoting movement, the clamping element pulls the film end out of the holding clamp 16, whereby the film end is carried along until it is clamped between the clamping elements.

[0061] List of reference symbols

[0062] Rotating arm winding system changing device support frame

[0063] Wrapping arm

[0064] Unwinding unit Reel chuck Roll arrangement Feed direction Loading area Change area Movable carriage

[0065] Carriage top first coil holder second coil holder guide unit guide surfaces clamp arm retaining clip

[0066] 16.1 , 16.2 Clamp bolts

[0067] 17 Transfer and fixing unit

[0068] 18 Clamping device 19 Slide guide

[0069] 20 recesses

[0070] 21 Slide housing

[0071] 22 motor drive

[0072] 23 pneumatic cylinder

[0073] E1 , E2 horizontal planes

[0074] F film spool

[0075] HA main axis of the transfer and fixing unit

[0076] P Palette R Rotation of the wrapping arm

[0077] RA rotation axis, rotation axis

[0078] S1 , S2 swivel movement

[0079] TR transport direction, conveying direction

Claims

Patent claims 1. A rotary arm wrapping system (1) for wrapping pallets (P) loaded with articles with a film that can be peeled off a film reel (F), comprising a changing device (2) for automatically changing the film reel (F), wherein the rotary arm wrapping system (1) comprises at least one support frame (3) with a winding arm (4) rotatably arranged thereon and having an unwinding unit (5), wherein the unwinding unit (5) of the rotatable winding arm (4) comprises at least one reel chuck (6) for supporting the film reel (F) and at least one roller arrangement (7) for guiding the film during wrapping, wherein the changing device (2) comprises at least one carriage (11) movable in a feed direction (8) between a loading area (9) and a changing area (10),wherein the movable carriage (11) has at least one first reel holder (12) for receiving an empty film reel (F) and at least one second reel holder (13) for receiving a full film reel (F), wherein the movable carriage (11) has a movably arranged guide unit (14) for guiding the film, wherein a clamp arm (15) movably arranged in the feed direction (8) is provided on the movable carriage (11) with a holding clamp (16) fastened at the free end for holding a film end, and wherein the changing device (2) further has a takeover and fixing unit (17) which is designed to take over and fix the film end from the holding clamp (16) and has a clamping device (18) which is adjustable in a controlled manner between an open and closed position for clamping the film end from the holding clamp (16).

2. Rotary arm winding system (1) according to claim 1, characterized in that the changing device (2) further comprises a carriage guide (19) for the guided movement of the movable carriage (11), wherein the movable carriage (11) can be moved between the loading area (9) and the changing area (10) by means of the carriage guide (19).

3. Rotary arm winding system (1) according to claim 1 or 2, characterized in that the changing device (2) further comprises a motor drive (22) which drives the movable carriage (11).

4. Rotary arm winding system (1) according to one of the preceding claims, characterized in that at least one first position which can be occupied by the movable carriage (11) and at least one second position which can be occupied by the movable carriage (11) are provided within the changing area (10), wherein the movable carriage (11) can be positioned in a fixed position in particular in each of the two positions.

5. Rotary arm winding system (1) according to claim 4, characterized in that the movable carriage (11) is positioned in the first position relative to the reel chuck (6) of the unwinding unit (5) of the rotatable winding arm (4) such that the empty film reel (F) can be transferred from the reel chuck (6) to the first reel holder (12) of the movable carriage (11).

6. Rotary arm winding system (1) according to claim 4 or 5, characterized in that the movable carriage (11) is positioned in the second position relative to the reel chuck (6) of the unwinding unit (5) of the rotatable winding arm (4) in such a way that the full film reel (F) can be transferred from the second reel holder (13) of the movable carriage (11) to the reel chuck (6).

7. Rotary arm winding system (1) according to one of the preceding claims, characterized in that the guide unit (14) arranged on the movable carriage (11) for guiding the film is designed to be liftable / lowerable and in particular can be moved into a carriage housing (21) of the movable carriage (11), preferably in such a way that the guide unit (14) can be lowered into a carriage upper side (11a) extending along a horizontal plane.

8. Rotary arm winding system (1) according to claim 7, characterized in that by lowering the guide unit (14) of the movable carriage (11), the film can be transferred to the roller arrangement (7) of the unwinding unit (5) of the rotatable winding arm (4), wherein in particular in the carriage housing (21) on the carriage top side (11a) recesses (20) for engagement of the roller arrangement (7) are provided.

9. Rotary arm winding system (1) according to claim 7 or 8, characterized in that the guide unit (14) has a plurality of guide surfaces (14') for guiding the film, wherein the guide surfaces (14') are arranged in particular countersunk in the recesses (20) on the carriage top side (11a) and are designed to correspond to the roller arrangement (7).

10. Rotary arm winding system (1) according to claim 9, characterized in that the guide surfaces (14') are designed as curved guide plates which can be lowered synchronously.

11. Rotary arm winding system (1) according to one of the preceding claims, characterized in that the holding clamp (16) arranged on the movable clamp arm (15) of the movable carriage (11) has two elongated clamp bolts (16.1, 16.2) arranged parallel to one another, which each extend horizontally in the longitudinal direction, in particular perpendicular to the feed direction (8).

12. Rotary arm winding system (1) according to claim 11, characterized in that the two clamp bolts (16.1, 16.2) are arranged in superimposed horizontal planes (E1, E2) and in particular form a lower (16.2) and an upper clamp bolt (16.1), wherein both clamp bolts (16.1, 16.2) are arranged in a common vertical plane running perpendicular to the superimposed horizontal planes (E1, E2).

13. Rotary arm winding system (1) according to one of the preceding claims, characterized in that the clamping device (18) which can be adjusted in a controlled manner between an open and closed position comprises two elongate clamping elements, wherein at least one of the two clamping elements, preferably both clamping elements, is / are designed to be pivotable about a respective pivot axis, wherein the respective pivot axis extends in particular substantially parallel to the feed direction (8).

14. Rotary arm winding system (1) according to claim 13, characterized in that in the closed position of the clamping device (18) both clamping elements extend vertically in their respective longitudinal direction and in particular protrude above the transfer and fixing unit (17).

15. Rotary arm winding system (1) according to claim 13 or 14, characterized in that at least one of the clamping elements, preferably both clamping elements, can be pivoted into a horizontal orientation over a respective pivoting angle range of approximately 90° and can thereby be lowered into the transfer and fixing unit (17).

16. Method for automatically changing film reels (F) in a rotary winding system (1) according to one of the preceding claims.

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