EP2484613B1 - Winder for winding film remnants - Google Patents

Description

The invention relates to a rewinder for winding film residues for packaging machines according to the preamble of claim 1.

A winding device of a thermoforming packaging machine for winding up waste strips such as edge strips and center strips goes out of the DE 1922848 out. The winding device has a shaft driven by a cutter on which rest one or more tubular winding body with its inner diameter. During winding arises between the winding bodies and the driven shaft slippage, which may be different, for example, due to differently wound waste strips for the winding body. A disadvantage is the undefined, significantly changing during winding slip, and that the winding body must be disposed of together with the wound waste strips.

Thermoforming packaging machines are also known, which in each case have an edge strip winder on both sides in a region in which a foil feed releases a foil web to be transported. Each Randstreifenwickler is driven with its own motor and turned on for a certain period for winding. Similarly, tray sealing machines are known which wrap a residual foil grid of the lid foil by means of a rewinder.

From the EP 1 655 258 A2 is a friction element for transmitting a certain torque to a winding core for winding tape-shaped materials such as adhesive tape known.

The EP 0 437 751 A2 discloses a winding shaft for simultaneously winding a plurality of web strips side by side with the same web tension with an adjustable torque.

The JP 60 204552 A discloses a winding shaft for sheet material with a very high winding force.

From the EP 0 994 54 A2 a winding device is known, which provides two torque adjustment discs, both of which have a plurality of permanent magnets and which are mutually adjustable in distance and thus the torque is variable.

The object of the present invention is to improve a rewinder for a packaging machine with regard to its use for winding waste strips and / or residual foil lattices.

This object is achieved by a rewinder for packaging machines with the features of claim 1. Advantageous developments of the invention are specified in the subclaims.

The rewinder according to the invention for winding film residues for packaging machines, preferably for thermoforming packaging machines, comprises a drive, a mandrel and at least two winding rollers and has an adjustment for adjusting a torque threshold, above which a slip between the individual winding rollers and the winding mandrel and / or between the Winding rollers occurs to each other. The adjusting device comprises coupling elements via which the mandrel transmits a torque to the winding rollers, and provides a machine operator according to the invention the ability to increase or decrease the torque threshold.

The advantage here is, on the one hand, that a common drive is provided for several winding rollers, which transmits its torque to the winding mandrel and the winding mandrel transmits the torque to the winding rollers via coupling elements. Above the set torque limit, slip may occur on the winding rollers independently of each other. The torque limit limits the maximum tensile force acting on a waste strip or a residual foil grid. When the drive is running and the feed of the packaging machine is stationary, the waste strips or the residual foil grid can no longer be wound up and the winding rollers can stop, even at different times, since the torque threshold is exceeded and the desired slip occurs without having to shut down the drive at this moment. The winding rollers can also rotate differently during winding. The adjustment of the torque threshold and thus the tensile force on the waste strip or the residual foil grid allows an adaptation to the material properties of the waste strip or the residual foil grid and leads to an improved process reliability during winding.

The adjusting device further comprises at least two cooperating permanent magnets. Such a magnetic coupling works wear-free even when running in continuous operation drive. Another advantage is that permanent magnets do not need to be powered.

The permanent magnets according to the invention in the axial direction of the winding mandrel relative to each other adjustable to adjust the torque threshold of the winding rollers to the winding mandrel.

Preferably, the adjustment device has a plurality of coupling rings, which are arranged laterally and / or between the winding rollers. This allows a simple and inexpensive construction.

The coupling rings are preferably made of the approved in the food industry material POM (polyoxymethylene).

Preferably, a dial for axially compressing the coupling rings and the winding rollers is provided on the winding mandrel to adjust the slippage continuously and in a simple manner by the operator of the packaging machine can.

It is particularly favorable if the setting wheel is attached to an end of the winding mandrel opposite the drive, since it is then located on the operating side of the packaging machine and is thus very easily accessible.

Preferably, a spring element is provided on the winding mandrel between the drive and the winding rollers, wherein the adjusting wheel is movable against the spring element to increase the torque threshold. This allows a very accurate adjustment of the common torque threshold of the winding rollers, which can nevertheless lead to a different time to a slip on the winding rollers.

Also advantageous is a mounted on the outer diameter of the winding roller bevel for easy removal of a wound film residue.

The winding rollers preferably have a plurality of roller elements, which can be spread radially to the winding mandrel by laterally mounted and axially displaceable clamping elements. Thus, prior to winding, the roller elements can be adjusted to a maximum outer diameter of the winding roller and, after winding, to slightly pull down film residues, the roller elements are reduced to a smaller outer diameter.

It is particularly suitable if the clamping element which is furthest away from the drive can be removed from the winding mandrel in order to be able to axially remove a rolled-up film residue from the device.

Preferably, the drive by means of a control of the packaging machine temporarily switched off to save energy and to minimize wear when using coupling rings.

In the following, an advantageous embodiment of the invention is explained in detail with reference to a drawing.

• Figur 1 eine schematische Seitenansicht einer Tiefziehverpackungsmaschine mit einem erfindungsgemäßen Aufwickler,
• Figur 2 eine schematische Ansicht eines Aufwicklers,
• Figur 3 eine Schnittansicht eines Aufwicklers,
• Figur 4 eine Variante eines Aufwicklers.

In detail show:

• FIG. 1 a schematic side view of a thermoforming packaging machine with a rewinder according to the invention,
• FIG. 2 a schematic view of a winder,
• FIG. 3 a sectional view of a rewinder,
• FIG. 4 a variant of a rewinder.

The same components are provided throughout the figures with the same reference numerals.

FIG. 1 shows a schematic view of a packaging machine 1 in the form of a thermoforming packaging machine. This thermoforming packaging machine 1 has a forming station 2, a sealing station 3, a cross-cutting device 4 and a longitudinal cutting device 5, which are arranged in this working order in a working direction R on a machine frame 6.

On the input side is located on the machine frame 6, a feed roller 7, from which a first web-shaped material 8 is withdrawn. In the area of the sealing station 3, a material reservoir 9 is provided, from which a second web-shaped material 10 is withdrawn as a cover film. On the output side, a discharge device 13 in the form of a conveyor belt is provided on the packaging machine, are transported with the finished, isolated packaging. Furthermore, the packaging machine 1, a feed device, not shown, which engages the first web-shaped material 8 and transported in a main working cycle in cycles in the direction of R. The feed device can be realized for example by laterally arranged transport chains.

In the illustrated embodiment, the forming station 2 is formed as a thermoforming station in which containers 14 are formed by deep drawing in the first sheet material 8. In this case, the forming station 2 may be designed such that in the direction perpendicular to the working direction R a plurality of containers are formed side by side. In the working direction R behind the forming station 2, an insertion path 15 is provided, in which the containers 14 formed in the first web-shaped material 8 are filled with product 16.

The sealing station 3 has a closable chamber 17 in which the atmosphere in the container 14 can be replaced prior to sealing, for example, by gas purging with a replacement gas or with an exchange gas mixture.

The cross-cutting device 4 is designed as a punch that cuts through the first web-shaped material 8 and the second web-shaped material 10 in a direction transverse to the working direction R between adjacent containers 14. In this case, the cross-cutting device 4 operates such that the first web-shaped material 8 is not divided over the entire width, but at least in an edge region is not severed. This allows a controlled onward transport by the feed device.

The longitudinal cutting device 5 is formed in the illustrated embodiment as a knife assembly with which the first web-shaped material 8 and the second web-like material 10 between adjacent containers 14 and the lateral edge of the first web-shaped material 8 are severed, so that behind the longitudinal cutting device 5 individualized packages 21 present. In this case, the bilaterally released foil remnants of the feed device are wound up as marginal strips 23 by a rewinder 22 according to the invention.

The packaging machine 1 also has a controller 18. It has the task of controlling and monitoring the processes taking place in the packaging machine 1. A display device 19 with operating elements 20 serves to visualize or influence the process sequences in the packaging machine 1 for or by an operator.

FIG. 2 shows the winder 22 with its drive 24 and two winding rollers 25a, 25b. In this case, limiting discs 26 are attached to clamping elements 27 and a dial 28 is provided for adjusting the torque threshold.

In FIG. 3 the rewinder 22 is shown with its winding mandrel 29. An adjusting device 50 has a dial 28, a coupling ring 30 between two clamping elements 27 of the two winding rollers 25a and 25b, and two further coupling rings 30 are between the outer clamping elements 27 and Mitnehmerbuchsen 31 which are rotatably connected by means of feathers with the mandrel 29, respectively , The drive 24, for example, a servo motor, transmits its torque to the mandrel 29 and the rotatably mounted on the winding mandrel 29 clamping elements 27. About an axial bias the clamping elements 27, the coupling rings 30 and roller elements 32a, 32b, the torque is further transmitted to the winding rollers 25a, 25b.

The following describes the operation in detail. The dial 28 is screwed onto the winding mandrel 29 and presses the outer Mitnehmerbuchse 31 via the outer coupling ring 30 on the outer clamping element 27 and in consequence on the roller elements 32a of the outer winding roller 25a and the further clamping element 27. In this case, the roller elements 32a radially outward adjusted until they are limited by a stop 34. Analogously, this also happens with the roller elements 32b of the inner winding roller 25b. After the roller elements 32a and 32b were limited by stops 34, the dial 28 acts on the outer coupling ring 30 and the winding roller 25a on the middle coupling ring 30 and the winding roller 25b on the inner coupling ring 30 and an inner Mitnehmerbuchse 31 on a spring 33, which is compressed. By further adjusting the dial 28 in the direction of the drive 24, the spring 33 is further tensioned and the force that acts equally on the coupling rings 30, and thus increases the torque threshold and increases the maximum tensile force on the film remnant 23.

Should marginal strips 23 wind up differently on the winding rollers 25a, 25b, respectively, the existing slip ensures that the winding rollers 25a, 25b can rotate differently relative to the winding mandrel 29 or the drive 24.

The coupling rings 30 may consist of the food approved material POM or a material that has the ability to change the friction force largely proportionally by changing the axial contact force.

The embodiment of the winder 22 is not limited to two winding rollers 25a, 25b. For example, in 3-lane thermoforming packaging machines 1 with additional center strip cuts between the tracks, two edge strips 23 and two center strips for winding up, and thus preferably the winder 22 has four winding rollers 25a, 25b. The individual winding rollers 25a, 25b may be of different widths.

Regardless of the number of winding rollers 25a, 25b, instead of a plurality of edge strips 23, a residual film grid can also be wound up, without requiring a retooling of the rewinder 22.

FIG. 4 shows a variant of a winder 35 with two cantilevered winding rollers 25a, 25b and a centrally disposed drive 24. The winding rollers 25a, 25b are each mounted on the winding mandrel 29 via a bearing 36a, 36b. On the mandrel 29 is on both sides of the drive 24 is arranged depending on a tubular permanent magnet 37a, 37b mounted rotationally fixed. A counter magnet 38a, 38b is mounted in each case in a bushing 39a, 39b, which is mounted on the bearing 36a, 36b. The overlap S of the inner magnet 37a, 37b and the counter magnet 38a, 38b determines the torque threshold of the winding roller 25a, 25b with respect to the winding mandrel 29, above which a slip occurs. The overlap S is adjustable via an axial adjustment of the counter magnet 38a, 38b in the sleeve 39a, 39b. The greater the overlap S between the inner magnets 37a, 37b and the respective associated counter magnets 38a, 38b, the higher the torque threshold above which slippage occurs or the higher the achievable take-up forces - and vice versa.

For axial adjustment of the counter magnets 38a, 38b, a locking screw 51 can be provided in each case, which passes through a slot 52 in the respective bushing 39a, 39b and is screwed with a thread in the respective counter magnets 38a, 38b. After loosening the locking screw 51, this can be moved along the slot 52, wherein it carries the counter magnets 38a, 38b and moves in the axial direction. As a result, the overlap S between magnet 37a, 37b and counter magnet 38a, 38b changes. It is conceivable for intermediate disks 53 of variable number to be inserted in the space resulting in the axial direction between magnet 37a, 37b and counter magnet 38a, 38b in order to determine the maximum achievable overlap S. Alternatively, the washers 53 could be omitted. In a further alternative, a motorized mechanism could be provided for axially displacing the counter-magnets 38a, 38b.

To remove a wound film residue 23 from the rewinder 35, the winding roller 25a with a limiting disk 41 and a handle 40 can be removed axially from the winding mandrel 29 after a detent pin 43 has been released. This applies analogously to the winding roller 25b. About a slope 44 on the outer diameter of the winding roller 25a, 25b, the film residue 23 can be easily pulled down.

The permanent magnet 37a, 37b, 38a, 38b may alternatively be at least partially designed as electromagnets.

The invention relates not only to the variants shown in the figures, but also, for example, to the combination of magnets 37a, 37b, 38a, 38b in a winder 22 with two winding rollers 25a, 25b as in FIG FIG. 3 or arranged on the combination of coupling rings 30 in a winder 35 with winding rollers 25a, 25b on a central drive 24 as in FIG. 4 , As explained, moreover, two winding rollers 25a, 25b may be provided.

Claims (10)

1. A winder (22, 35) for winding film trims (23) for packaging machines (1), comprising a drive (24), a winding mandrel (29) and at least two winding rolls (25a, 25b), wherein the winder (22, 35) comprises an adjustment device (50) for adjusting a torque threshold above which slip occurs between the respective winding rolls (25a, 25b) and the winding mandrel (29) and/or between the individual winding rolls (25a, 25b), wherein the adjustment device (50) comprises at least two cooperating permanent magnets (37a, 37b, 38a, 38b, and the permanent magnets (37a, 37b and 38a, 38b) are adapted to be adjusted relative to one another in the axial direction of the winding mandrel (29).
2. A winder according to claim 1, characterized in that the adjustment device (50) comprises a plurality of coupling rings (30) arranged laterally and/or between the winding rolls (25a, 25b).
3. A winder according to claim 2, characterized in that the coupling rings (30) are made of POM.
4. A winder according to claim 2 or 3, characterized in that an adjustment wheel (28) for axially compressing the coupling rings (30) and the winding rolls (25a, 25b) is provided on the winding mandrel (29).
5. A winder according to claim 4, characterized in that the adjustment wheel (28) is arranged on an end of the winding mandrel (29) that is located opposite the drive (24).
6. A winder according to one of the preceding claims 2 to 5, characterized in that a spring element (33) is provided on the winding mandrel (29) between the drive (24) and the winding rolls (25a, 25b), the adjustment wheel (28) being movable against the spring element (33) so as to raise the torque threshold.
7. A winder according to one of the preceding claims, characterized in that the winding rolls (25a, 25b) are provided with a bevel (44) for removing a wound-up film trim (23).
8. A winder according to one of the preceding claims, characterized in that the winding rolls (25a, 25b) comprise a plurality of roll elements (32a, 32b), which can be forced apart radially to the winding mandrel (29) by means of laterally arranged and axially displaceable tensioning elements (27).
9. A winder according to claim 8, characterized in that that at least the tensioning element (27) which is most remote from the drive (24) is adapted to be removed from the winding mandrel (29) so that a wound-up film trim (23) can be removed axially from the winder (22, 35).
10. A winder according to one of the preceding claims, characterized in that the drive (24) can be switched off temporarily by means of a controller (18) of the packaging machine (1).

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