EP1266828A1 - Method and apparatus for wrapping stacks of articles in a stretchable foil cover or sleeve - Google Patents

Abstract

Device for surrounding a load has a roller (14) arranged in a hook (1) in the horizontal moving path of the roller (13) on the upper edge section (17). Preferred Features: The roller is arranged in the known manner central to the hook and/or the roller (14). The roller (14) has the cross-section of the edge section of the hook. The roller (14) can be reversibly driven.

Description

The present invention relates to a method for partially enveloping unit loads, esp. (usually arranged on a flat pallet) i.w. cuboid or cube-shaped General cargo stacks, each with a plastic one, generally from a gusseted tube formed, hood or tubular stretch film wrapping, the scope smaller in the unstretched initial state (generally considerably) than in the stretched wrapping state is, in which the supplied lower edge portion of the wrapping film of several (generally four) bow-shaped (hereinafter also referred to as "bow") Multifunctional elements are picked up and spread (at least largely without stretching), the film is thrown onto the brackets by reversible drivable reefing rollers is cross-stretched, and in the cross-stretched (working) state over the respectively to be wrapped General cargo unit is pulled.

The present invention further relates to a device for partially enveloping General cargo units, especially (usually arranged on a flat pallet) i.w. cuboid or cube-shaped General cargo stacks, each with a plastic one, generally from a gusseted tube formed, hood or tubular stretch film wrapping, the The circumference in the unstretched initial state (generally considerably) is smaller than in the cross-stretched state Wrapping condition is, with several (usually four) arranged on a common lifting frame, relative to each other from an approximated exposure position biaxially horizontally (= diagonal) in a pull-over position, bow-shaped Multifunctional elements ("ironing") for the respective recording and i.w. unstretched Spreading open the lower edge section of the tubular wrapping film fed to the brackets, to hold the concentric to the hood or hose longitudinal center axis running folds of hood-shaped or tubular wrapping foil torn up on the brackets, for horizontal stretching of the wrapping foil torn up on the brackets, and for covering the cross-stretch wrapping film over the piece goods unit to be wrapped, the brackets in a top view from above each (generally isosceles) Have an L-shape with a rounded central (temple) apex area on which an i.w. straight outer side section connects, whereby continues from I. W. horizontal upper edge of each bracket, which is held / supported on the lifting frame L-shape of its upper edge i.w. the following, i.w. flat (bracket) support section extends downward, and finally each bracket has an arranged on the lifting frame, horizontally movable reef unit with a reversibly drivable reef roller is assigned, the outside rest position moved away from the assigned bracket to the outside the bracket assigned to it is to be brought up, in particular to carry out the aforementioned Process.

When a "partial" wrapping is mentioned above or below, it refers to this is due to the fact that when using a hood-shaped stretch film covering, for only five of the six stacking surfaces are encased in a cube-shaped piece of goods (namely the four stack side faces), and when using one tubular stretch film wrapping only the four stack side faces, making the stack in the finished wrapping state is therefore not completely wrapped in film. If you want the latter in a method of the type described above or by means of a device of reach the genus described above, so it must (and can) possibly on the (the) of the stretch film wrapping not (at least not completely) enveloped stack surface (s) a flat film be put on or put on. If, therefore, before or after a "wrapping" the What is said is only the (partial) wrapping that is to be understood with a hood or tubular stretch film wrapping can be achieved.

A hood-shaped stretch film wrapping, which a unit good not only on their Side surfaces, but also completely covered on their top, is then provided, in particular if a stack of general cargo is not just opposite one because of the stretch film wrapping its non-enveloped state can be given increased stack strength (dimensional stability) should prevent relative movement of general cargo parts or entire general cargo layers, but if the general cargo unit also provides protection against weather influences and / or pollution should / must be lent.

Such weather protection is regularly required by practice, but is in Exceptional cases can be dispensed with, for example if the unit goods to be wrapped are around palletized (wall) stone piles or the like. acts that neither against weather influences through rain or snow, also against dusting or other pollution are sensitive. In such cases, a cost is often used for reasons of cost no hood-shaped formation of the stretch film covering, and accepted, that on the top of the piece goods units, which is not or only partially covered by film when storing and transporting moisture and dirt particles under the film packaging of the general cargo units that are only completely encased on their side walls can, because if you do not have a hood-like design of the stretch film covering considerable savings are made in film material, and from an economic point of view Since time immemorial, efforts have been made to implement the required Packaging required amount of relatively expensive plastic film on the absolutely reduce required measure. That is why they work in film packaging technology also with the thinnest possible films and a relatively large horizontal cross stretch.

The (ironing) problem underlying the present invention, discussed below is largely independent of whether general cargo units with a stretch film hood or should only be wrapped with a tubular stretch film section. The present Invention is therefore intended and suitable for both ways of working. If so before or after a "stretch film wrapping" is mentioned without expressly is placed on a hood-shaped or tubular stretch film covering, so can therefore be one or the other form of stretch film wrapping.

Furthermore, there are problems with the (ironing) problem on which the present invention is based less dependent on whether the stretch film wrappings (e.g. the film hoods) are outside prefabricated the wrapping device and then assembled it in a suitable manner are supplied, or whether in the wrapping device a hood forming device or a device for providing lengthwise formatted tube sections is integrated, as is the case with automatic stretch film wrapping devices nowadays is the case regularly. In such a case, a generic wrapping device for a hood-shaped stretch film wrapping, a hood forming device, by means of which a stretch film tube, in particular a gusseted tube, Hose material from an i.a. hose reel is to be fed into a roll, and therein a welding and cutting device, by means of which before wrapping the General cargo is to be formed a hood. In the case of a provided tubular The welding device is omitted from stretch film wrapping, or it becomes available with changing working methods not used.

The method and apparatus of the type (s) described in the introduction have been in existence for over a decade known (see e.g. EP 0 399 540 or EP 0 460 681), and differ fundamentally hardly from each other.

An early forerunner of today's hood stretcher is the FR-A-2 in the early 1970s 230 549 has been disclosed, but that device does not include any of the brackets of the above (and in Preamble of claim 4) had the type and number described, but only two each other opposite sides of the piece goods unit to be wrapped i.w. about the entire depth of the receiving sheet to be wrapped / packaged (with a bar-shaped head section), which the supplied Pick up the film tube and pull the hood formed from it over the enveloping piece goods should allow, so that an impact of the film only two (of the four) pages took place, as was later also provided in US Pat. No. 4,050,219, but where instead of the laterally continuous receiving plates horizontally movable stand up to four corners of a lifting frame.

Already in the device known from FR-A-2 230 549 is in another embodiment for threading and bellows-like folding (reefing) of the film tube (or a hood made from a hose section) in each of the two mounting plates a (abutment) role provided, each at the same height as an assigned drivable reef roller, which is at a vertical distance from the top of the concerned Receiving plate in the area of the (abutment) rollers can be pivoted towards them is.

Especially for loading units that are packed (wrapped) using a stretch film hood it is generally advisable to format the hood with regard to its length so that it is just before the end of the wrapping process up to the bottom of the general cargo or pallet extends downwards so that the lower hood edge section, which yes - like the hood side walls overall - during the pulling process i.a. considerably stretched, so is stretched by at least 10% (generally considerably more) after sliding off the brackets with elastic contraction with a so-called "understretch" to the piece goods or Pallet underside created. This is not only extremely useful, but even indispensable, if the stretch film hood not only in the horizontal direction during the wrapping process stretched across, but also stretched lengthways in the vertical longitudinal direction, thus also subjected to a biaxial stress state overall in the hood side walls (see EP 0 344 815). Because if it is not or only to an insufficient understretch comes, the film usually pulls at least between the piece edges due to the internal vertical longitudinal stresses impressed by the vertical longitudinal stretch upwards (so-called crescent or sickle formation), so that the desired longitudinal stretch again (at least partially) is lost.

In order to prevent this, EP 0 633 186, already mentioned above, and the EP 0 461 667 measures have been proposed which ensure a secure understretch, namely a reduction in the pulling speed in the final pulling phase or / and moving the brackets inwards in the final pulling phase - the latter preferred until underneath the general cargo or the pallet supporting it - creating a fixed system the hood side walls with considerable static friction on the general cargo side walls is achieved before the lower edge section held by the brackets under transverse stretch the hood slides off the brackets, so that with this measure (s) in a simple manner and effective way a safe understretch (without other possibly complex further measures) can be achieved.

Nevertheless, there have been recent developments in generic methods and devices Especially in the final pull-over phase there are certain difficulties that arise - especially with relatively large vertical longitudinal stretch and / or relatively low horizontal transverse stretch - can also have a negative impact on the understretch. Among other things, the fact that one of several Reasons (e.g. the least possible use of material for packaging with the aim of high dimensional stability even after a long storage period or several relocations etc.) increasingly works with larger transverse stretch of 50% and more after the film manufacturer provide appropriate stretch films, the stretch of 70% and endured more harmless. Such high strains now call - i.w. same other film properties provided - correspondingly higher internal tensions emerge in the film, with the result that the film in the overcoating state with a correspondingly high pressure on the Ironing is present, so that not only the static friction is large, but also the (Sliding) frictional forces that are impressed on the film as it slides off the brackets. However, these cause an uneven sliding of the film when covering over the respective too enveloping general cargo unit.

Now you could, for example, the coefficient of friction between the brackets and the film. by polishing the ironing surface coming into contact with the film or its sliding coating For example, reduce with tetrafluoroethylene, like this in a relatively early stage Phase of the stretch film packaging technology (1982) proposed in EP 0 092 922 such a measure (apart from the fact that it is even more extreme Elongation conditions should hardly suffice, the difficulties mentioned here Avoid safely) especially when creating loading units with biaxially stretched Hood (see EP 0 344 815) is extremely unsuitable because of a vertical longitudinal stretch of the hood The easiest way (without other additional devices) is to pull through Friction is to be imprinted, so that a planned reduction in the coefficient of friction insofar as it would be counterproductive.

The present invention has for its object the method of the above Genus (see also preamble of claim 1) or the device of the above Genus (see also preamble of claim 4) in particular to improve that Foil during the entire coating process including the final coating phase itself with relatively high pressure on the brackets properly (i.e. generally evenly) from the brackets slides, so that i.a. a satisfactory understretch can also be achieved.

The procedural part of the above object is achieved according to the invention in that the stretches stretched from the temples and those in the opposite direction to meet driven reef rollers i.w. wrapping film pressed in the middle of the bracket at Covering over the piece goods unit to be wrapped in each case, that is to say when it is removed from the Iron, controlled in alignment above each reef roll - preferably free of sliding friction - to is moved to the upper edge of the bracket, at which it leaves the respective bracket, the pressure force exerted by a reef roller on the film and / or the speed of the Reef roller is preferably adjustable to the sliding process with respect to the controlled film movement to be able to control in the middle area above the reef roll.

The solution of the device part of the above object is according to the invention in that each bracket in its central (crown) area with a (foil conveyor) device is provided, by means of which the cross-stretched wrapping film, which is gathered onto the brackets in the pull-over position of the stirrups during the pull-over operation above the in doing so - mostly by pinching the film - i.w. in the middle of the bracket and in the opposite direction to the direction of rotation when reef is driven, until you leave of the upper edge of the frame is controllably moved over the frame, preferably free of sliding friction, as explained further below in various configurations becomes.

The present invention is inter alia and especially the knowledge that when used the one already above and bracket described in more detail below as multifunctional elements in the implementation of the entire wrapping process on the one hand, it is necessary for the film to come up in the middle of the bracket when the film hits it Reef rollers should act on the temples with a vertical distance from the upper edge of the temple leave so that the foil picked up by the brackets (mostly without stretching) when it hits from the reef rollers (due to friction between reef roller and film) at the respective contact point between reef roller and film due to friction between reef roller and the (outside the) film is to impress a downward tensile force that is able to the film also downwards on the side bracket areas not acted on by the reefing roller to pull on / over the respective bracket. Instead, the reef roles are instead adjacent to the upper temple edge or even in the area of the upper temple edge section when reefing the frame, the foil to be torn off is in the side area of the frame not impress a sufficiently large vertical tensile force (component), so that in the side bracket areas no problem can be achieved. This applies in particular if the upper bracket edge section bulges over the adjoining it downwards Protrudes, as has been practiced for a long time, in this way when the film is subsequently pulled off the brackets on account of such Edge formation to achieve an undercut, with which the film to achieve a larger vertical longitudinal stretches during the pulling process greater vertical tensile forces have it stamped.

On the other hand, a film section in the central temple area when pulling off the Ironing is no longer exposed to uncontrolled sliding friction during the pulling process after the contact point between reef roller and bracket up has left, if he successively evenly from the upper edge of the temple should slide the bracket, as in EP-B-0 564 971 or DE 93 07 716 U1 Case is. There are in each bracket at a considerable distance below the upper edge of the bracket provided, central recess each two immediately adjacent, arranged one above the other with a horizontal axis of rotation to which the reefing roller of the assigned reefing unit is to be moved from the outside so that it in the middle between the two bracket abutment rollers. The may be - as stated - useful when hitting film on the bracket (especially the impact in the two temple side areas running laterally to the middle temple area is still supported by friction-reducing measures), however not helpful when pulling the film off the brackets during the pulling process. Because as soon as a film section the reef roll or the upper of the two abutment rolls left when pulling upwards, it gets above the upper abutment roller again inevitably (as already below the lower abutment roller) on the bracket below uncontrolled sliding friction, and must also the undercut area between the bead-shaped upper bracket edge section projecting outward toward the bracket support section overcome. This is particularly problematic for the lower edge section of the film hood, when the free lower edge of the film comes up to the two abutment rollers Reef roller or left the upper abutment roller upwards. Because then the free lower edge section of the film, which is still on the brackets, is subject to the yes, the stirrup is even more stretched in the pull-over position than in the later system condition on the general cargo unit, uncontrolled considerable sliding friction forces, and this in general For an understretched and therefore - as stated - particularly critical film section behaves exactly the same as in earlier generic methods and devices, where the brackets do not have any kind of roller arrangement at all were provided.

In order to solve the problem already described, the lower one in particular must also be used Edge section of the stretch film wrapping as free of sliding friction as possible up to the upper edge of the frame be moved. So there are for the impact of the film on the one hand and peeling film from the temples, on the other hand, seemingly conflicting conditions, which are reconciled by the present invention.

In a generic device in which the upper edge of the bracket (at least is rounded in its middle area, and there at least on its upper side), and which of the i.w. flat temple support section in its central area below its upper edge section is provided with a window-like recess is gem. a preferred embodiment of the present invention provided that in the middle A reversible drivable, vertical (small) belt conveyor with one in itself closed flat belt is arranged as a conveyor belt, which at its upper end from upper bracket edge section and at its lower end by a lower deflecting element is deflected, its outer one strand ("upper strand") on the outside and its inner another run ("lower run") runs on the inside of the flat bracket support section.

This is not only a preferred one, but also a particularly simple one device-like solution, which - even if one of the assigned to each bracket Reef role - role-free can be designed, and still taking into account the above findings in the problematic removal of the film during the coating process gives significantly better results than a device with brackets, the one have known one or two-roller arrangement.

Because if the window-like central recess arranged at a distance from the upper edge of the bracket each bracket has a width that is at least as large (preferably somewhat larger) is like the width of the flat belt, as well as a height that is at least as big as that Thickness of the flat belt (preferably slightly larger) and the upper edge of the window-like Bow recess runs horizontally and is rounded down, it can form the lower deflection element for the flat belt (see also embodiment according to 2 and 3) without the bracket need to be provided with a roller assembly, the desired goal of a perfect meeting on the one hand and a perfect one On the other hand to achieve sliding of the film when covering. Because if the one Bracket each assigned reef roller in the area of the lower belt deflection Top edge of the window-like bracket recess when the film hits the The bracket is moved to the assigned bracket under pressure, and the film between the reef roller and the outside of the belt, practice the reef rollers in each case at a distance from the upper edge of the temple in the middle of the temple due to friction pointing downwards Tensile forces on the film, which also in the side bracket areas to hit impress sufficient (friction) tensile forces, especially since the film still (at least i.w.) is not cross-stretched, and therefore not significantly outside of the reef role Pressure is applied to the flat belt, which - especially if it is pretensioned in the longitudinal direction - remains at rest because the friction between the inside of the flat belt and the Flat belt deflections at the upper edge of the frame and at the upper edge of the window-like Recess i.a. is significantly larger than between the reef roller and the film.

On the other hand, should later pull off the cross-stretched film which has been torn up on the brackets during the covering process, the film gradually slides off the brackets Foil already due to the considerable horizontal stretch under accordingly high pressure also on the flat belts of the (small) belt conveyors. This proof will by pressing against the flat belts or between the flat belts and The reef roll-running film at the contact point between reef roll and film is still noteworthy increased so that when pulling in the opposite direction of rotation as when reefing Driven reef rollers only act on the film with rolling friction, and thereby the Drive the flat belt of the (small) belt conveyor over the film firmly attached to it. Everyone Foil section is without significant relative movement to the flat belt of this carried along without sliding friction until he has left the upper edge of the frame. This also applies to the lower free edge portion of the stretch film wrap. Because as soon as the bottom free The flat belt becomes the edge of the contact point between the reef roller and the flat belt no longer via the film, but driven directly by the reef roller, see above that the lower free edge portion of the film the bracket - from the flat belt or from the controlled with this reefing roller engaged in friction - leaves controlled.

Since - as already stated - the upper edge section of the bracket has been around for a long time expediently protrudes in a bead-like manner over the bracket support section in order to so that an undercut between the upper bracket edge section and To achieve support section, by means of which the film is particularly when pulling off the brackets have large frictional forces impressed, and this measure is generally zweickmäßigerweise by realizing that the upper bracket edge section with a circular Cross-section forms, the diameter of which is greater than the thickness of the support section by one on the support section formed as a bent sheet metal a correspondingly shaped Round rod section welded, creating the upper deflection point for the flat belt therefore takes place on a larger diameter than at the lower deflection point, which is therefore at the previously treated design allows only relatively thin flat belts, is functional in one Similar variant provided that the window-like recess (more precisely whose upper edge) the bracket does not itself serve as the lower deflecting element, but an in Recessed, cylindrical deflection element with horizontal longitudinal central axis, which prefers i.w. has the same diameter as the rounding at the top Ironing edge portion.

Such a cylindrical lower deflection element per bracket can in a further embodiment of the present invention as a roller rotatable about its longitudinal central axis (“lower roller”) be formed, but it can also be non-rotatable in another embodiment be arranged in the bracket (in its recess), so that it is basically has the same (deflection) function as in the embodiment described above, in which the flat belt on the rounded horizontal top edge of the window-like Recess is deflected.

However, such a configuration can also take on a further function, in particular when the cylindrical lower deflection element is not on it Longitudinal central axis is attached to the bracket support section, but each on an eccentric to its longitudinal central axis extending eccentric axis, and when doing so for the purpose of tension of the flat belt can be pivoted about its eccentric axis in the unlocked state, as well as in the selected clamping position can in turn be locked on the support section during operation (See also training according to Fig. 4, 5).

A variant of the embodiment described above is that between the cylindrical lower deflecting element and the upper edge of the bracket around its longitudinal central axis rotatable abutment roller is arranged with a horizontal axis of rotation, to which the reefing role of the assigned reefing unit (when reefing and pulling off film from the brackets) is to be moved under pressure. This configuration (see also FIG. 5a) has the opposite the previously described the significant advantage that the flat belt, because of its "external drive" not to be biased nearly as much by the reef roller needs like belt conveyors with drum or roller belt friction drive so that it when pulling the film off the brackets, it is actually no problem via its deflection points no one slides at the point of greatest pressure (through the reef roller) on the inside Sliding friction, but rolling friction is subjected because it is there on the rotatable abutment roller is supported.

In a further variant of the present invention, the upper edge section can in each case a bracket in the middle bracket area of a roll rotatable about its longitudinal central axis ("Top roller") be formed, the length of which is expediently at least as long as that Width of the reef roll. This top roller therefore forms the upper flat belt deflection, the lower deflection can take place in the manner already described, preferably but by means of a lower roller (see also Fig. 6 - 18).

Such a design, in which in each bracket (at least) two arranged one above the other Rollers are arranged, one of which (top roller) is a central section of the upper bracket edge section, opens the possibility, if necessary, even without (small) belt conveyor get along, taking into account the findings explained above - Then, when the reef rollers (at least) with each time the film hits the bracket the lower roller are engaged, and when pulling the film off the brackets (at least) with the top roller (if necessary, of course, with the interposition of the film), e.g. if the reef units are designed or arranged so that their reef role each optionally to the Lower roll or the upper roll of a bracket is to be moved up. This can be achieved if the Reefing roller of a reefing unit can be swiveled between two positions or moved in height (see e.g. Fig. 8 - 18).

In addition, it has been found that i.a. is more convenient if the diameter of the Reef roller is significantly larger than the diameter of the ironing roller (s), and / or if one Two-roller arrangement per bracket the diameter of the lower bracket roll significantly larger than is the diameter of the top bracket roll.

Furthermore, it has proven to be extremely advantageous if the reef rollers (and / or possibly the bow rollers) are spherical, because in this way a possible lack Compensate or parallel axis parallelism in a simple and effective manner can eliminate their negative influence.

Finally, it should be pointed out that in principle at least one can also be seen Bow roller can be designed as a reversibly drivable (small) drum motor, and regardless of whether with flat belt training or without (small) belt conveyor (and instead, a height-adjustable reefing roller) is used, but such a configuration is obviously much more complex, so that i.a. will refrain from doing so, especially since desired effects can also be achieved with considerably simpler means.

Preferred embodiments of the present invention are in the subclaims described.

Fig. 1

eine etwas schematisierte Teildraufsicht auf wesentliche Bestandteile (bügelförmige Multifunktionselemente; zugeordnete Reffeinheiten) einer Stretchfolien-Verpackungsmaschine in Richtung des Pfeiles I in Fig. 2 gesehen;

Fig. 2

eine gegenüber Fig. 1 erheblich vergrößerte Teildarstellung eines Bügels in einer Seitenansicht von außen gem. dem Pfeil II in Fig. 1 gesehen;

Fig. 3

einen mittleren vertikalen Teilschnitt durch die Darstellung gem. Fig. 2 in Richtung der Schnittlinie III-III gesehen;

Fig. 4

eine Bügel-Variante in einer Darstellung gem. Fig. 2;

Fig. 5

einen mittleren vertikalen Teilschnitt durch die Darstellung gem. Fig. 4 in Richtung der Schnittlinie V-V gesehen;

Fig. 5a

eine weitere Bügel-Variante in einer Darstellung gem. Fig. 3 bzw. Fig. 5;

Fig. 6

eine weitere Bügel-Variante in einer Darstellung gem. Fig. 2 bzw. Fig. 4;

Fig. 7

einen vertikalen Mittelschnitt gem. der Schnittlinie VII-VII in Fig. 6 durch einen Teil des Bügels gem. Fig. 6, jedoch in einer gegenüber Fig. 6 verkleinerten und vereinfachten schematische Darstellung;

Fig. 8

die Anordnung gem. Fig. 7 mit einer modifizierten zugeordneten Reffeinheit, die zwischen einer abgesenkten ersten Betriebsstellung und einer gegenüber dieser angehobenen zweiten Betriebsstellung vertikal verfahrbar ist;

Fig. 9

eine Anordnung gem. Fig. 7 in der Aufreff-Arbeitsstellung, bei welcher die Reffrolle der Reffeinheit in einer vertikalen Ebene begrenzt schwenkbar ist;

Fig. 10

die Anordnung gem. Fig. 9, wobei sich die Reffrolle in ihrer hochgeschwenkten Abgleitstellung befindet;

Fig. 11

eine Anordnung gem. den Fig. 9 und 10 in weniger schematisierter Darstellung, bei welcher sich die Reffeinheit in ihrer Ruhestellung außer Eingriff mit dem ihr zugeordneten Bügel befindet, und eine Reffrolle aufweist, deren Durchmesser erheblich größer als der Durchmesser der beiden übereinander angeordneten Bügel-Rollen ist;

Fig. 12

die Anordnung gem. Fig. 11 in einer ersten Arbeitsstellung der Reffeinheit, in welcher die Reffrolle beim Aufreffen von Folie auf den Bügel - unter gleitbarem Einklemmen der Folie - im Eingriff mit der unteren Rolle des Bügels ist;

Fig. 13

die Anordnung gem. den Fig. 11 und 12, wobei sich die Reffeinheit in einer hochgeschwenkten zweiten Arbeitsstellung befindet, in welcher sich ihre Reffrolle - unter Einklemmen von Folie - im Eingriff mit der im oberen Randbereich des Bügels angeordneten Oberrolle befindet;

Fig. 14

eine Anordnung mit einer Reffeinheit gem. den Fig. 11 - 13, bei welcher die untere Rolle des Bügels einen größeren Durchmesser als dessen Oberrolle aufweist, wobei sich die Reffeinheit gem. Fig. 11 in ihrer Ruhestellung außer Eingriff mit dem ihr zugeordneten Bügel befindet;

Fig. 15

eine Anordnung gem. Fig. 14 in einem Betriebszustand gem. Fig. 12;

Fig. 16

eine Anordnung gem. den Fig. 14 und 15 in einen Betriebszustand gem. Fig. 13;

Fig. 17

eine Anordnung gem. den Fig. 11 - 13 in einem Betriebszustand gem. Fig. 13, bei welcher die Reffrolle (abweichend von der zylindrisch ausgebildeten Reffrolle bei dem Ausführungsbeispiel gem. den Fig. 11 - 13) ballig ausgebildet ist, in einer Seitenansicht gem. dem Pfeil XVII in Fig. 18;

Fig. 18

eine Draufsicht auf die Anordnung gem. Fig. 17 in Richtung des Pfeils XVIII in Fig. 17 gesehen;

Fig. 19

eine Draufsicht von oben den Bügel gem. den Fig. 2 und 3 in Richtung des Pfeiles XIX in Fig. 2 gesehen;

Fig. 20

den Bügel gem Fig. 6 in einer Darstellung gem. Fig. 19; und

Fig. 21

den Bügel gem. den Fig. 9 und 10 (d.h. eine Zwei-Rollen-Anordnung ohne Flachriemen) in einer Darstellung gem. den Fig. 19 und 20.

The invention is explained in more detail below using exemplary embodiments with reference to a drawing, the notes given in some cases not being only example-specific, but in some cases recognizable also generally refer to the present invention. It shows:

Fig. 1

a somewhat schematic partial top view of essential components (bow-shaped multifunctional elements; assigned reefing units) of a stretch film packaging machine in the direction of arrow I in FIG. 2;

Fig. 2

a considerably enlarged partial view of a bracket in a side view from the outside according to FIG. the arrow II seen in Fig. 1;

Fig. 3

a medium vertical section through the representation acc. Figure 2 seen in the direction of section line III-III.

Fig. 4

a bracket variant in a representation acc. Fig. 2;

Fig. 5

a medium vertical section through the representation acc. 4 seen in the direction of section line VV;

Fig. 5a

another bracket variant in a representation acc. Fig. 3 and Fig. 5;

Fig. 6

another bracket variant in a representation acc. Fig. 2 and Fig. 4;

Fig. 7

a vertical middle section acc. the section line VII-VII in Fig. 6 by part of the bracket acc. FIG. 6, but in a simplified and simplified schematic illustration compared to FIG. 6;

Fig. 8

the arrangement acc. 7 with a modified assigned reefing unit, which can be moved vertically between a lowered first operating position and a second operating position raised relative to this;

Fig. 9

an arrangement according to Fig. 7 in the working position, in which the reefing roller of the reefing unit can be pivoted to a limited extent in a vertical plane;

Fig. 10

the arrangement acc. Fig. 9, wherein the reefing roller is in its swiveled sliding position;

Fig. 11

an arrangement according to Figures 9 and 10 in a less schematic representation, in which the reefing unit is in its rest position out of engagement with the bracket assigned to it, and has a reefing roller, the diameter of which is considerably larger than the diameter of the two stirrup rollers arranged one above the other;

Fig. 12

the arrangement acc. 11 in a first working position of the reefing unit, in which the reefing roller is in engagement with the lower roller of the hoop when the film hits the bracket - with the film being slidably clamped in;

Fig. 13

the arrangement acc. 11 and 12, wherein the reefing unit is in a swung-up second working position, in which its reefing roller is in engagement with the upper roller arranged in the upper edge region of the bracket, with the film being clamped in;

Fig. 14

an arrangement with a reef unit acc. 11-13, in which the lower roll of the bracket has a larger diameter than its upper roll, the reefing unit according to FIG. 11 is in its rest position out of engagement with the bracket assigned to it;

Fig. 15

an arrangement according to 14 in an operating state according to Fig. 12;

Fig. 16

an arrangement according to 14 and 15 in an operating state according to. Fig. 13;

Fig. 17

an arrangement according to 11-13 in an operating state acc. 13, in which the reefing roller (deviating from the cylindrical reefing roller in the exemplary embodiment according to FIGS. 11-13) is spherical, in a side view according to FIG. arrow XVII in Fig. 18;

Fig. 18

a top view of the arrangement acc. 17 seen in the direction of arrow XVIII in FIG. 17;

Fig. 19

a top view of the bracket acc. Figures 2 and 3 seen in the direction of arrow XIX in Fig. 2.

Fig. 20

6 according to a representation of the bracket. Fig. 19; and

Fig. 21

the bracket acc. 9 and 10 (ie a two-roller arrangement without flat belt) in a representation acc. 19 and 20.

1 shows a simplified partial top view of exemplary components of a Device for wrapping unit loads 1, namely cuboid or cube-shaped General cargo stacks with a square cross-section, with one made of plastic (e.g. / especially polyethylene) existing, hood-shaped stretch film wrapping 2, which wrapped a finished (Packaged) general cargo unit 1 on its four side surfaces below it by transverse expansion stamped inner circumferential tension completely wrapped around the unit 1 the underside of which underpins from the edges with a so-called understretch, and therefore also this is partially enveloped, and due to the hood-like design of the stretch film envelope also completely covers the top of the piece goods unit 1.

For this purpose, the device is designed with a gusseted tube (not shown) Hose supply made of plastic stretch film provided in the flat folded Supply state is coiled up to a hose reel, from which in each case if necessary Tubular film is fed. The device therefore has a (not shown) i.w. out Support and deflection rollers on existing feed device, by means of which each for wrapping a piece of unit 1 fed to the device, a hose section from Hose supply is withdrawn and fed to the piece goods unit 1 to be wrapped so that at the beginning of a packaging cycle, the free end section of the film tube above the hanging freely to each enveloping unit 1.

Since the hose material is folded flat in the state of storage, and the same "sticking" to adjacent hose layers due to adhesive forces, the film tube must first be suitably opened at its free end section so that it can then be picked up by recording elements and continue can be treated so that it is finally pulled as a hood over the unit 1 can be. This pre-opening can, for example, by suction heads or the like. happen by are approached from the outside to the free hose end section, and / or e.g. by wedge-shaped, sword-like pre-opening elements in the feed movement path of the film tube and when pulling the hose over these elements ensure that that it is opened so far at least at its free end section that suitable receiving elements can be inserted into the free hose end.

Several four i.a. arranged on a common drivable lifting frame 14, bracket-shaped receiving elements ("bracket") 3, however, during the further process flow have several other functions, and therefore as "multifunction elements" can be designated. They are not just for recording of the free hose end section, for which it is in a diagonal to the longitudinal axis of symmetry collapsed recording state can be moved into the free hose end, but afterwards also for the expansion-free spreading of the free hose end section, whereby from its recording position (generally synchronous) horizontally into a Spread position be moved apart.

This spreading position also forms the reefing position of the bracket 3, in which Hose material in required length in i.w. concentric folds to the longitudinal axis of the hose is reefed by means of reefing rollers 7 on the brackets, which act as abutments and holding means serve. This impact occurs through so-called reefing units 5, each of which has a bracket 3 are assigned a reversible at their end section facing the relevant bracket 3 have drivable reef roller 7, and from an external rest position so horizontally the stirrups 3 are to be moved up so that the reefing roller 7 is each under an adjustable pressure abuts on the outside of the bracket 3 assigned to it. In this case, the unexpanded spread film 2 between the outside of each bracket 3 and the reefing roller 7 of the reefing unit 5 associated therewith arranged / clamped, so that the in Impact direction 8 driven reef roller 7 each with frictional film on the associated one Bracket 3 can hit. The reefing rollers 7 expediently have an elastic one Coat 7 '.

Fig. 1 shows in its middle part over one indicated by dash-dotted lines General cargo unit 1, the longitudinal center axis of which is designated by M, four such bow-shaped Multifunctional elements (bracket) 3 in their spread or reef position. With regard on the cube-shaped configuration of the piece goods stack 1 with a square cross-sectional area the brackets 3 are symmetrical to the longitudinal central axis in each working position M arranged, namely in their in Fig. 1 with solid lines Spread and Aufstellstellung each in a corner area of the one they recorded and unexpanded expanded film tube, which as a film hood 4 over each enveloping general cargo stack 1 is to be pulled. Because the film hood 4 is supposed to be finished Wrapping condition with considerable horizontal (circumferential) transverse expansion on the side surfaces of the stack 1, so that they are accordingly in the still unexpanded expansion state must have a correspondingly smaller scope than the stack 1.

Before the stirrups 3, in particular with reference to FIGS. 2-6 and 19-21, continue in detail are explained with reference to FIG. 1 that the reefing units 5, itself when the film tube is picked up and spread apart in its outward direction Rest position, as shown in Fig. 1 bottom left, according to there indicated double arrow 6 are translationally horizontally back and forth, namely from the rest position in which its reefing roller 7 has a distance a from the respectively assigned one Has bracket 3, in a reef position (= spread position), as shown in Fig. 1 below is shown as an example on the right. All four reef units 5 are in this reef position with their reef roller 7 on the outside of the film tube / film hood 4, and this again with its inside on the outside of the respective bracket 3 Refrollen 7 driven in the direction of rotation indicated by an arrow 8, so is Hose material withdrawn from the hose supply and concentric with the longitudinal central axis M running folds up on the bracket 3. The investment site is located here each reef roller 7 at a distance f below the upper edge of the bracket 15 'because the film 2 otherwise not by those generated by the reefing rollers 7 centrally on the respective bracket 3 Frictional forces could be pulled over the side portions 3 '' of the bracket 3, which is on both sides to the central temple-apex region 3 '(see in particular FIGS. 1 and 19-21): it would are already caught on the outer edge regions of the curved central apex region 3 '.

As soon as a sufficient amount of film material has been thrown onto the bracket 3, two drive Welding jaws (not shown) of a stack (not shown) above the piece goods stack 1 arranged welding device together with pinching the film tube, and weld this with a transverse seam 11, since in the embodiment shown in FIG. 1 the piece goods stack 1 not only wrapped with a wrapping hose section which is not the top of the stack in the finished wrapping state (at most partially) covered, but with a film hood 4 closed at one end.

To form them, the tube section provided with a cross weld 11 is above the previously formed cross weld 11 with a cutting device (not shown) separated from the hose supply, so that the closed hood end between the four brackets 3 falls down, and there hangs down like a bag. Because it is often not only extremely useful to create optimal loading units, but also i.a. indispensable that the closed hood end 10 (generally referred to as "hood cover") in the finished wrapping condition not stretched or even in folds on the top of the General cargo stack 1 rests, but - like the hood side walls - is biaxially taut, After detaching the hood 4 from the hose supply, a so-called follow-up takes place of the reefing rollers 7 driven in the reefing direction raised until the hood cover 10 is (at least i.w.) tightened, and the bracket 3 are then from their spread and reef position acc. arrows 9 (also synchronous) diagonally move to the longitudinal center axis M outwards into a pull-over position in which they each a safety distance s of i.a. about 10 - 15 cm to the piece goods stack 1 to them When pulling over the film hood 4, lower it collision-free by means of the lifting frame 14 to be able to. This pull-over condition is shown in FIG. 1 at the top on one of the four brackets 3 shown in the cutout.

When pulling over, the hood cover 10 therefore lies on the top 39 of the piece goods stack 1 and thus forms an abutment against which the hood 4 when lowering the Bracket 3 can slide / be pulled off the bracket 3 successively.

If the hose material as in the embodiment shown in Fig. 1 there is a gusseted tube, the transverse seam formed during welding is 11 in its middle region 11 'in two layers and in each of its two outer regions 11 " four layers. The hood cover 10 has two mirror-symmetrically opposite one another V-shaped or triangular multilayer film areas 12, which are also used as film pockets can be referred to because they each have their baselines of rectangular Triangle-forming edge 13 are open.

In the following, the brackets 3 are exemplified, in particular, with reference to FIGS. 2-6 and 19-21 described. All four brackets 3 are attached to a common lifting frame 14, which is in an upper end position (starting position) at the beginning of each packaging cycle is located, and can be lowered from this in a controlled manner. The bracket 3, which in the pioneering era of Stretch hood packaging technology i.a. were finger-shaped, are in their middle (apex) area 3 'curved, and point on both sides to the curved middle section 3 'then an i.w. stretched or in plan view i.w. linear side section 3 ". The upper edge section 15 of each bracket 3 has one circular cross section with a diameter d. It is centered on one in the top view I. W. welded in the same way bow-shaped support section 17 with welds 18. Since the thickness b of the support section 17 is smaller than the diameter d of the upper one Edge section 15 of each bracket 3, the upper edge section 15 is therefore inward and in particular also outwards via the support section 17, so that each on the outside Bracket 3 created an undercut 19 below its upper edge portion 15 is because the hood 4 when pulled over the stack 1 in addition to the horizontal Querstretch a vertical longitudinal stretch to be embossed by means of the bracket 3, for which the mentioned undercut 19 in order to increase the frictional force between the film and the brackets 3 is highly useful.

Because the stretch film packaging technology increasingly works with larger transverse stretch is because the film manufacturers are now making films available that do not further tolerate an elongation of 50% and in part significantly more harmless Working with such a high transverse stretch in the system state to a still clear leads to higher transverse expansion in the covering state, but the film in the covering position of the Bracket 3 should slide off the brackets 3 successively during the pulling process, and this with such high strains leads to considerable problems if the film in the curved slide the middle vertex areas of the bracket 3 with sliding friction from them must, according to the invention, special measures are provided to solve these problems.

The bracket designated as a whole with 3. 2, 3 and 19, which is in a plan view of above (Fig. 19) an isosceles L-shape with a rounded central apex area 3 ', on each of which an i.w. straight outer side section 3 ″ connects, and of its upper compared to the bracket support section 17 thickened Edge section 15 an i.w. flat support section 17 is directed downwards, on the Lifting frame 14 (horizontally movable) is held in its central (apex) area 3 'with a - according to the exemplary embodiment. Fig. 2 by no means over the entire curved apex region 3 'extending - designated overall with 50 (foil conveyor) device provided, by means of which (in cooperation with the assigned Reef roller 7) is not only to be dropped onto the respective bracket 3, but by means of which in particular also includes the cross-stretched wrapping film, which is gathered onto the brackets 3 in the Pull-over position of the stirrups 3 during the pull-over process above the center of the respective Drive bracket 3 up and driven in the opposite direction to the direction of rotation when reefing Reef roller 7 can be controlled via the bracket 3 until it leaves the upper bracket edge 15 ' is to be moved.

For this purpose, the bracket 3 according to 2 and 3 below its upper edge 15 'and also still clearly below the upper edge section 15 in its from the assigned reef roll 7 actable, central area a reversibly drivable, vertical (Small) belt conveyor 51 with a self-contained flat belt 52 as a conveyor belt, that at its upper end from the upper bracket edge portion 15 and at its lower end is deflected by a lower deflection element 53, so that its outer one strand ("upper strand") 54 on the outside and his inner different run ("lower run") 55 on the inside of the flat bracket support section 17 extends.

The endless flat belt 52 is by a below the upper bracket edge portion 15 in Supporting section 17 provided centrally, window-like recess 56 (and only after that made endless), whose downward rounded upper edge is the lower deflecting element 53 for forms the flat belt 52. That provided with a greater distance f 'to the upper edge of the bracket 15' window-like recess 56 has a width g that is slightly larger than the width h of the flat belt 52, and a height j which is slightly larger than the thickness k of the flat belt 52, the rest of Fig. 3 (in relation to the other dimensions) for better For the sake of clarity, it is thicker than is actually shown.

For / when hitting film on the bracket 3 by means of a program-controlled Overall control device the reefing units 5 synchronously in accordance. the arrow 27 in Fig. 3 against moved the bracket 3 assigned to them so that their reefing roller 7 with a predetermined set pressure is applied to the assigned bracket 3. The reef rollers 7, which according to the arrow 8 are driven in the pickup direction, but not directly against the bracket support section 17, since its axis of rotation 28 is at a distance f below of the upper bracket edge 15 ', which is slightly smaller than the distance f' of the window-like Recess 56 to the upper edge 15 '. Because the outer end of the bracket 3 facing the Ref roller 7 is still in the height range of the belt 52, but is also not immediate pressed to this, but to the free of the brackets 3 before reefing fed end section and stretched-free stretched film.

Because the friction between the inside of the flat belt 52 and the upper bracket edge portion 15 or the upper edge 53 of the recess serving as the lower deflection 56 is significantly greater than the friction between the inside of the film and the outside of the flat belt, the film slides on / from the outside of the belt during the reefing process in the middle of the frame (in folds) down on the bracket support section 17 when its on its outside a downward frictional force is impressed by the reefing rollers 7. It is also the impact of the film on the bracket side sections located on both sides of the flat belt 52 3 "without any problems, since the foil is embossed by a reef roller 7 Frictional force with a considerable distance f to the upper edge of the bracket 15 'is generated, so that vertical tensile force components also in the bow areas lying on both sides of the flat belt 52 result in a problem-free impact on the bracket 3 without further ado guarantee if no friction-reducing measures have been taken there.

When the film is subsequently pulled off the brackets 3 during the pulling-on process, they are Relationships - as already explained above - are completely different: since the subtraction of the Film from the brackets 3 in the pull-over position of the bracket 3, in which the film on strongest horizontally stretched, it is then already due to its large inner Circumferential tensions with considerable pressure on the brackets 3 - and thus also on the Flat belt 52 of their (small) belt conveyor 51 - on. The counter during the pulling process the reef rotation direction (counter to the arrows 8) driven reef rollers 7 shape the the flat belt 52 tightly fitting film in turn under pressure - now vertically upward - frictional force on. But since the friction between the film and Flat belt 52 correspondingly because of the considerably higher pressing force in the pull-over position is larger than when reefing, the flat belts 52 of the (small) belt conveyors 51 become driven and moved by the reef rollers 7 (as it were by "external drive") over the film according to the arrows 57 around their deflection points 15 and 53, each section of film, who has left the contact area with the reef roller 7 upwards, without relative movement to the belt 52 is taken from the upper run 54 and the bracket 3 on leaves upper temple edge 15 'free of sliding friction. This also applies to the tubular one lower edge section of the film when the free lower film edge is away from the contact point has moved up with the reef roller 7. Because even then he stays in close contact with the friction with the flat belt 52, which is gradually free of sliding friction above the reefing roller 7 moved upwards until finally the lower edge of the foil 15 'the upper bracket edge after completely controlled sliding movement.

Simply because in the design according to 2 and 3 only relatively thin straps 52 are used Since the lower deflection 53 is relatively narrow, it is generally expediently (and also not significantly more complex), also the lower deflection of the flat belt 52 similar to the upper deflection, namely in the window-like recess 56, which is then only a little larger, also a cylindrical lower deflection element 53 ', as shown in FIGS. 4 and 5. It can also be a such cylindrical lower deflection element 53 ', which is preferably approximately the same Has diameter d as the upper bracket edge portion 15, as in the bracket gem. 2 and 3 to be fixed. It then works i.w. just like the temple training according to 2 and 3, but due to the cheaper Umlenl (but thicker ratios Flat belt 52 can be used.

If you provide such training, it expediently points to the cylindrical lower deflection element 53 'at the same time a tensioning function for the flat belt 52. As has already been explained above, the tension force for the flat belt 52 not to be particularly big in each case, but there is a certain preload possibility for the Flat belt 52 proved to be extremely useful. This is easy to do achieve that you do not have a cylindrically shaped lower deflection element 53 ' Longitudinal central axis 58 attached to the support portion 17 of the bracket 3, but via eccentric protruding from the longitudinal central axis 58 on the end faces of the cylindrical deflection element 52 ' Axle stub 59. If you provide a lockable and unlockable attachment, it can the cylindrical deflection element 53 'thus under tension of the flat belt 52 about the eccentric axis 16 pivoted in the unlocked state and then locked again.

Instead, however, a cylindrically shaped lower deflection element 53 'can also be attached its longitudinal central axis 58 to be attached to the support section 17 of each bracket 3, if necessary also freely rotatable. This has the advantage that the flat belt 52 at the contact point Ref roller 7, on which the highest pressure prevails, not with sliding friction over the as Abutment serving role 53 'needs to slide. However, the (simple) option is possible a belt tension lost.

However, this is not the case if one provides for both of the aforementioned measures, namely a stationary lower cylindrical deflection element 53 'during operation, which unlockable with stub axles 59 arranged eccentrically to its longitudinal center axis 58 is attached to the support portion 17 to tension the flat belt 52 in this simple manner to be able to, and additionally a "center roller" freely rotatable about its longitudinal center axis 61 62 (which is the only rotatable "roller" during operation, since the cylindrical lower one Deflection element 53 'is then arranged in a rotationally fixed manner as the upper bracket edge section 15). Such an arrangement is shown schematically in Fig. 5a.

When training the stirrups acc. Fig. 6 (as well as Figs. 7-18) is the lower deflection 53 ' Straps 52 each like the center roller 61 in the configuration according to Fig. 5a formed and arranged. But then in the upper edge region 15 of each bracket 3 in the up to Upper bracket edge 15 'extending recess 50 of each bracket 3 a second (upper) role ("Top roller") 20 is provided, which according to the embodiment. Fig. 6 the same Has diameter d as the lower roller 53 ', and with a center distance e so aligned above the lower roller 53 'is arranged so that there is a significant distance between the two Rollers 20, 53 'is present.

In this embodiment, too, the two rollers arranged vertically one above the other form 20, 53 'of each bracket 3 with the endless flat belt 52 in turn a "passive belt conveyor", whose "deflection drums" are formed by the two rollers 20 and 53. As These (small) belt conveyors 52 are to be called “passive” because neither of the two "Drums" 20 or 53 'is directly driven, as is the case with a normal belt conveyor is the case, the drive drum of the (drive) torque introduced into it transfers frictionally to the conveyor belt. With the "passive belt conveyors" 20, 52, 53 'the Bracket 3 acc. 6 ff. The drive is provided in reverse: namely two rollers 20, 53 'driven by the belt 52, and this in turn by the reefing roller 7 the respective reefing unit 5 (if necessary via the film 2), as will be explained in more detail below is described.

FIG. 7 shows one in a highly schematic and reduced representation compared to FIG Section through part of a bracket 3 acc. the section line VII-VII in Fig. 6 to the Interaction with the associated reefing unit 5 or its reefing roller 7, for example clarify. The reef roller 7 is dash-dotted in the right part of FIG. 7 in its rest position located. You can from this according to arrow 27 in a with solid lines Working position shown on the roller assembly 20, 53 'or its belt (flat belt) 52 are brought up, first by clamping the film 2.

If foil is to be thrown onto the bracket 3 during the impact process, then that rotates in each case Reef roller 7 in the direction of arrow 8. Should, however, already foil on the bracket 3 are controlled in sections or completely "removed", and each under controlled intervention of the reef roller 7 in question slide from the bracket 3, the reef rollers 7 are thereby in Driven in the opposite direction to arrow 8.

It has now been shown in the course of the development on which the invention is based that it is neither necessary nor always expedient if the reefing roller 7 both when it hits of film 2 on the bracket 3, as well as when hitting or sliding off film 2 of the brackets 3 is always in engagement with both rollers 20, 53 ', as is the case with the arrangement gem. Fig. 7 is the case in which the axis of rotation 28 of the reefing roller 7 in the middle between the axes of rotation of the two rollers 20, 53 ', and both rollers 20, 53' the same Have diameter d. Rather, it is more appropriate if the reef roller 7 is one Bracket 3 assigned reefing unit 5 when hitting film on the bracket 3 only with the lower roller 53 'of each bracket 3 is engaged, and in the coming off (sliding) of film the brackets 3, so when pulling over when the film is under considerable transverse expansion, only with the upper roller 20.

8 shows an arrangement for such a mode of operation in a highly schematic representation, in which the reefing unit 5 is in turn initially in one with dash-dotted lines shown rest position is out of engagement with the bracket 3 assigned to it which according to arrow 29 when approaching the lower roller 53 ' and then / thereby the arrow 8 is to be driven.

When the impacting process has ended, the reefing unit 5 moves back against the arrow 29 move to the outside in their rest position, and then - or already during this reversing process - In a raised in Fig. 8 top right with dash-dotted lines Rest position, and that along a vertical guide 30, from which it at the appropriate time (at the latest shortly before the start of the pulling process) acc. the arrow 29 in turn on the bracket 3 is approached, but this time on its upper roller 20.

Such or a similar configuration, at least one such mode of operation, can be done with or done without strap 52. Since its mode of operation is evident in such a way of working compared to the working method. Fig. 7 resigns, can usually without loss of quality to be dispensed with the belt 52. Such an embodiment is shown in FIGS. 9 and 10, FIG. 9 again showing the impact process, and FIG. 10 the pulling process. The training acc. 9 and 10 differs from the training acc. the fig. 7 and 8 also in that the reefing roller 7 of each reefing unit 5 relative to it from its middle position acc. the arrow 31 limits down into a reef position, or acc. the To pivot arrow 32 in FIG. 10 upward into a stripping or film sliding position is.

11-13 give such a configuration of a reefing unit 5 in a less schematic manner Representation again. It differs from the training or presentations gem. 7-10, among others. in that the reefing roller 7 is already in the rest position of the reefing unit 5 has the height position for the pulling process, and from this for contacting Foil on the bracket 3 is pivoted up, and also in that the cylindrical, with an elastic jacket 7 'provided reef roller 7 has a considerably larger diameter has as the two rollers 20, 53 'of each bracket 3, and that the upper roller 20, the after as before has the same diameter d as the lower roller 53 ', to the latter to the outside is offset since the upper edge portion 15 of the bracket 3 with its support portion 17 a Undercut 19 forms, and the lower roller 53 'centrally in the wall of the support section 17 is stored.

The reefing units 5 are simultaneously made to hit film on the brackets 3 their rest position shown in Fig. 11 acc. arrow 27 translationally to each moved to assigned bracket 3, specifically so (see FIG. 12) that the reef roller 7 under "pinching" the film under the specified pressure and at the specified speed in the direction of rotation gem. the arrow 8 (only) has moved to the lower roller 53 'of the bracket 3 in order to Slide in i.w. auffeffen concentric folds on the support portions 17 of the bracket 3.

After the reeling process has ended, the reefing units 5 can again be in their rest position (see Fig. 11) can be retracted (but possibly also initially in their Impact position remain).

Should the film slide off the brackets 3 at a later time, i.e. when pulling over are controlled with successive sliding, so the Reefing units 5 each by means of a piston-cylinder unit 33 around an articulation point 34 on Lifting frame 14 pivoted so high that its reefing roller 7 is now under a predetermined pressure and with reversed direction of rotation (and possibly a different speed than when hitting) at the middle section of the upper edge section 15 of the bracket 3 upper roller 20 abuts so that now the previously ruffled film in the direction of the arrow 35 from the brackets 3 or pull off in a controlled manner during the pulling-on process.

14-16 show in representations acc. 11 - 13 a variant in which the lower roller 53 'of each bracket 3 has a considerably larger diameter than the upper one Roll 20, but the diameter is significantly smaller than the diameter of the reef roll 7. The other relationships are i.w. as in the arrangement according to 11-13.

The training acc. 17 and 18 in turn corresponds to i.w. the training acc. the Fig. 11 - 13, with the essential difference that the jacket 7 'of the reef roller 7 each is spherical, as in the top view of the arrangement acc. 17 in FIG. 18 is recognizable. Compared to only cylindrical rollers 7, 20, 53 ', this variant has the great advantage that edge pressure should be avoided if the axes of rotation 36 (the Ref roller 7), 37 (the upper roller 20) and 38 (the one under roller 53 ') are not exactly parallel to each other run. But that is even with careful production with a three-roller arrangement esp. with a portable role (here: the reef role 7), the alternating (horizontal) movable and also about a pivot axis 34 arranged at a distance from it is pivotable on a vertical plane, and alternately on two with mutual Roll-up rollers 20, 53 '(with a still considerably smaller diameter) are brought up must not be easily adhered to with usual manufacturing tolerances. comes it then leads to a relative inclination of the axes 36 and 37 or the axes 36 and 38, the desired goal is not - at least not in - with only cylindrical rollers the desired ideal way - to achieve.

Instead of this, the two rollers 20, 53 'can be spherical, or all three rollers 7, 20, 53' could have a certain crown have, especially since the jacket 7 'of the reefing rollers 7 expediently made of an elastic Material exists, and compensate for certain irregularities in the axis parallelism can.

Finally, FIGS. 19-21 show again in a greatly enlarged manner compared to FIG. 1 Representation of top views of the bracket 3 recognizable at the bottom left in FIG. 1. The other three Brackets 3 are each formed in the same way.

Fig. 19 corresponds to the bracket designs acc. 2 to 5a, Fig. 20 the bracket designs gem. 6 - 8, and Fig. 21 the bracket designs acc. Figures 9-18. It is recognizable in each case that the width h of the flat belt 52 is not nearly over the entire curved middle apex region 3 'of the bracket 3 extends with a middle Radius of curvature r is curved like a quarter arc, but only a fraction of the entire central bracket area 3 '.

Accordingly, even if the upper bracket edge section 15 is designed as a roller 20 whose length 1 in relation to that of the entire curved central vertex region 3 'arc must be relatively small in order to achieve the desired effects, regardless of whether a flat belt 52 is used (FIG. 20) or without (Small) belt conveyor 51 (Fig. 21). Only the realization that a relatively narrow "active" central apex section to achieve the effects sought according to the invention sufficient, it made it evidently possible, possibly in the middle of the upper edge section 15 to work with a roller 20 rotatable about its longitudinal central axis, since this may be on its Coat can be spherical, but not - like the rest of the curved middle Vertex area 3 '- curved in plan view.

As can already be seen from the exemplary embodiments discussed above, result there are numerous variants for the method of operation provided according to the invention. All of the invention Embodiments in common is that the driven in the direction of reef Reefing rollers 7 when film hits the bracket 3, each with a given pressure to the film 2 resting on the brackets 3 in a manner known per se with a vertical spacing to the middle of the upper temple edge 15 'of the film 2 in the middle temple-vertex region 3' Imprint such a vertically downward tensile force (component) that the Film also on both sides adjacent to the engagement area of the respective reef roller 7 without any problems aufpfeffen on the respective bracket 3, and that when removing the film during the Pull-over process in the pull-over position of the stirrups 3, strongly horizontally cross-stretched film when it slides off the brackets 3 by means of the then reversely driven for reefing, likewise under predetermined pressure on the reef rollers 7 moved up to the upper bracket edge 15 'is controlled / controlled over the middle bracket sections (with the foil sections on both sides of the reef roller engagement area necessarily takes controlled), including the lower edge of the film. Even if the free lower edge of the film already has the reef roller engagement area has left upwards, but is still on the brackets 3, he should / must still (in the central temple-vertex area) are moved upwards in a controlled manner and should / may not slide uncontrollably from the brackets 3, because just the free lower film edge section in With regard to the i.a. desired understretch is the most critical section of film that the The quality of the substretch that can be achieved plays a major role.

LIST OF REFERENCE NUMBERS

1

article unit

2

Stretch film wrapping; foil

3

hanger

3 '

mid-vertex area (out of 3)

3 ''

Side sections (of 3)

4

(Film) cover

4 '

Film wrapping tube section

4 ''

Haubendeckel

5

Reffeinheiten

6

double arrow

7

Reef roll (of 5)

7 '

elastic coat (from 7)

8th

arrow

9

arrow

10

Haubendeckel

11

cross seam

11 '

middle range (out of 11)

11 ''

outer areas (of 11)

12

Plastic bags

13

Rand (out of 12)

14

lifting frame

15

top edge section (of 3)

15 '

upper temple edge

17

Support section (of 3)

18

welds

19

undercut

20

Roll (in 15)

27

arrow

28

Axis of rotation (of 7)

29

arrow

30

guide

31

arrow

32

arrow

33

Piston-cylinder unit

34

articulation

35

arrow

36

Axis of rotation (of 7)

37

Axis of rotation (of 20)

38

Axis of rotation (of 25)

39

Top (of 1)

39 '

Edges (from 39)

50

(Film conveying) means

51

(Small) belt conveyors

52

Flat belt (from 51)

53, 53 '

lower deflection element (for 52)

54

Obertrum (of 52)

55

Lower strand of (52)

56

Recess (in 17)

57

arrow

58

Longitudinal central axis (from 53 ')

59

Stub axle (from 53 ')

60

Eccentric axis (from 53 ')

61

Longitudinal center axis (of 62)

62

Central role

M

Longitudinal central axis

a

Distance (7/3)

s

safety distance

d

Diameter (from 15)

b

Thickness (out of 17)

e

Center distance (20/25)

f

Distance reef roller 7 / upper bracket edge 15 '

f '

Distance from recess 56 / upper edge of bracket 15 '

G

Width (from 56)

H

Width (from 52)

j

Height (from 56)

r

Radius (of 3)

1

Length (of 20)

Claims (24)

Method for wrapping piece goods units (1), in particular cuboid or cube-shaped piece goods stacks, each with a plastic or hood-like or tubular stretch-film wrapping (2), the circumference of which in the unexpanded initial state is smaller than that of the cross-stretched one If the free lower edge section of the wrapping film (2) supplied to the piece goods unit to be wrapped (1) is picked up by several bow-shaped multifunctional elements ("ironing") (3) and spread (at least mostly unexpanded), the film (2 ) is thrown onto the brackets (3) by reversible drivable reeling rollers (7), is horizontally stretched horizontally, and is pulled over the piece goods unit (1) in the cross-stretched (covering) state, characterized in that the brackets (3 ) cross-stretched and driven by the reefing rollers (7) in the opposite direction with iw The wrapping film (2), which is pressed onto the brackets (3) when pulled over the general cargo unit (1) (= when it is successively pulled off the brackets (3)), is moved in alignment above each reefing roller (7) in a controlled manner up to the upper bracket edge (15 ') becomes. Method according to Claim 1, characterized in that the film (2) is moved in alignment above the respective reefing roller (7) without sliding friction up to the upper edge of the bracket (15 '). Method according to claim 1 or 2, characterized in that the pressing force exerted by a reefing roller (7) on the film (2) and / or the speed of the reefing rollers (7) is adjustable. Device for wrapping piece goods units (1), in particular cuboid or cube-shaped stacks of pieces, each with a plastic or hood-shaped or tubular stretch film wrapping (2), the circumference of which in the unexpanded initial state is smaller than that in cross-stretched The wrapping condition is, with several (generally four) arranged on a common lifting frame (14), biaxially horizontal (= diagonally) into a pull-over position, bifurcated multifunctional elements (= "bows") (3) arranged relative to each other in relation to the respective one Picking up and expanding the tubular lower edge section of the wrapping film (2) fed to the brackets (3), Holding the wrapping film (2) which is torn onto the brackets (3) in the folds running concentrically to the longitudinal axis of the hood or hose (M), horizontal transverse stretching of the wrapping foil (2), and the Covering the cross-stretched wrapping film (2) over the piece goods unit (1) to be wrapped, The brackets (3) each have a (generally isosceles) L-shape in a plan view with a rounded central apex region (3 '), which is adjoined on both sides by a generally straight outer side section (3''), from the generally horizontal top Edge (15 ') of each bracket (3), supported on the lifting frame (14), the L-shape of its upper edge (15') iw downward, flat support section (17), and each bracket (3) one horizontally movable reefing unit (5), which is arranged on the lifting frame (14), is associated with a reversibly drivable reefing roller (7), which from a rest position with a vertical distance (f) to the upper bracket edge (15 ') to the outside of the bracket (3 ) is to be driven, in particular to carry out the method according to one or more of the preceding claims, characterized in that each bracket (3) in its central (apex) region (3 ') with a (film conveyor) device ( 50) is provided t, by means of which the cross-stretched wrapping film (2) in the pull-over position of the stirrups (3) is aligned during the pulling-up process above which - mainly with the film (2) being pinched - in the middle of the stirrup (3) and counter to the direction of rotation (8) during reefing, the reefing roller (7) can be moved in a controllable manner via the hoop (3) until it leaves the upper hoop edge (15 '). Apparatus according to claim 4, characterized in that the wrapping film (2) in each case in alignment above the reef roll (7) moved to the bracket (3) by means of the (film conveying) device (50) to move without sliding friction over the bracket (3) is. Apparatus according to claim 4 or 5, wherein the upper edge (15 ') or the upper edge portion (15) of the bracket (3) is rounded at least in its central region on its upper side, and wherein the support section (17) in its central Area below its upper edge (15 ') or edge section (15) is provided with a window-like recess (56), characterized in that a reversible drivable, vertical (small) belt conveyor (51) is provided in the central bracket area (3') a self-contained flat belt (52) is arranged as a conveyor belt, which is deflected at its upper end by the upper bracket edge section (15) and at its lower end by a lower deflecting element (53; 53 '), its outer one strand ( "Upper run") (54) on the outside and its other inner run ("lower run") (55) runs on the inside of the generally flat bracket support section (17). Apparatus according to claim 6, characterized in that the window-like recess (56) arranged at a distance (f ') from the upper bracket edge (15') has a width (g) which is at least as large as the width (h) of the flat belt (52) and a height (j) which is at least as large as the thickness (k) of the flat belt (52), the upper edge (53) of the recess (56) forming the lower deflection element for the flat belt (52) runs horizontally and is rounded down. Apparatus according to claim 5 or 6, characterized in that a cylindrical lower deflection element (53 ') with a horizontal longitudinal central axis (58) is arranged in the recess (56). Device according to claim 8, characterized in that the cylindrical lower deflection element (53 ') is designed as a roller which can be rotated about its longitudinal central axis (58). Device according to claim 7, characterized in that the cylindrical lower deflection element (53 ') for the flat belt (52) is arranged in a rotationally fixed manner during operation. Apparatus according to claim 10, characterized in that the cylindrical lower deflection element (53 ') is in each case attached to an eccentric axis (60) extending eccentrically to its longitudinal central axis (58) on the support section (17) of the bracket (3) and in the unlocked state for the purpose of tensioning of the flat belt (52) is pivotable about its eccentric axis (60). Apparatus according to claim 11, characterized in that between the lower deflection element (53 ') and the upper bracket edge (15') is arranged a (abutment) roller (62) with a horizontal axis of rotation (61) which can be rotated about its longitudinal central axis and to which the The reef roller (7) of the assigned reef unit (5) can be moved under pressure. Device according to one or more of claims 4 to 12, in particular according to claim 9, characterized in that the upper edge section (15) of the brackets (3) in the middle bracket area each of an (upper) roll (20) which can be rotated about its longitudinal central axis ) is formed. Apparatus according to claim 13, characterized in that the length of the top roller (20) is at least as large as the width of the reef roller (7) assigned to it. Apparatus according to claim 13 or 14, wherein the upper bracket edge section (15) is thickened relative to the bracket support section (17) and has an essentially circular cross section, characterized in that the (upper) roller (20) is essentially the same Has diameter (d) like the bow edge portion (15). Device according to one or more of the preceding claims 6-15, characterized in that the (small) belt conveyors (50) of the brackets (3) can each be driven by means of a drum motor which drives the lower deflection roller (53 ') or the abutment roller ( 62) or the upper roller (20). Device according to one or more of claims 6-15, characterized in that the flat belt (52) of the (small) belt conveyor (50) is to be driven in each case by the reefing roller (7) of the associated reefing unit (5) which is moved towards it. Device according to one or more of claims 13-17, characterized in that two rollers (20, 53 ') arranged one above the other are arranged in each bracket (3). Apparatus according to claim 18, characterized in that the reefing rollers (7) when film (2) strikes the brackets (3) (at least) on the lower roller (53 ') and when film (2) is pulled off the brackets ( 3) (at least) to be moved towards the upper roller (20). Apparatus according to claim 19, characterized in that the reefing unit (5) is designed or arranged in such a way that its reefing roller (7) in each case optionally on the lower roller (53 ') or on the upper roller (20) of a reefing unit (7 ) assigned bracket (3) is to be moved up. Apparatus according to claim 20, characterized in that the reefing roller (7) of a reefing unit (5) can be pivoted or moved in height between two working positions. Device according to one or more of claims 18-21, characterized in that the diameter of the reefing roller (7) is in each case significantly larger than the diameter of the ironing rollers (20, 53 '). Apparatus according to claim 22, characterized in that the diameter of the lower bracket roll (53 ') is significantly larger than the diameter of the upper bracket roll (20). Device according to one or more of claims 4-23, characterized in that the reefing rollers (7) are spherical.

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