EP0328876A2 - Device for unfolding tubes lying flat - Google Patents

Abstract

A device is described for unfolding paper tubes (2) lying flat and having a longitudinal sealing seam (4), which are to be made into packages for liquids, comprising a transport means for seizing the tube (2) lying flat and guiding it into an axially aligned position between a mandrel and an ejector. <??>So that the tube can be held open reliably in a high work cycle to give a shape having a square cross-section, the longitudinal sealing seam always coming to lie at a defined point, the invention provides that the transport means comprises a distributing rocker having sheet metal holding plate (51) and centring web (56) which can be swivelled approximately about a semi-circle, the folding stop (10) which lies opposite the centring web (56) and has receiving faces arranged in a V-shape being provided in a stationary manner, that swivel levers (13) having vacuum openings (24) are provided swivellably on both sides next to the folding stop (10) in such a way that two bearing planes (14) in each case bounding a swivel lever (13) hold open a V-shaped roof corresponding to two side faces (72) of the unfolded tube (2) lying next to one another, and that the ejector is provided at its front with a square plate, has a stroke which is greater than the length of the swivel levers (13) and which can be moved back and forth along the bearing planes (14) which have been set in a V-shape, in a manner which is controlled synchronously with respect to the swivel movement of the distributing rocker (51, 56, 57). <IMAGE>

Description

The invention relates to a device for unfolding flat-lying sleeves made of paper, cardboard or the like with longitudinal sealing seam, in particular for the production of liquid packs, with a transport device for gripping the flat-lying sleeve and introducing it into a position axially aligned between a mandrel and an ejector.

The invention is directed to all types of sleeves, which are used in particular for the production of superplasticizers, and is described for the purposes of illustration and better understanding with the aid of liquid packs.

Packaging for milk, juices and the like is known which has a sleeve made of paper with a plastic coating, one end of the sleeve being closed by folds with a square bottom and the other, opposite end of the sleeve having a molded-on cover without a carrier material, i.e. is made of pure plastic. Sleeves in the form of a tube with an essentially circular cross section are known here. Machines constructed for the production of such packs have at least one mandrel wheel with a plurality of mandrels, the sleeve first being formed from a paper web (with a plastic coating) to form a longitudinal sealing seam and then being pushed onto the mandrel so that at one end the later cover, on which the pouring device is included, is injected. The mandrel on which the sleeve is pushed practically represents the inner shape, around which a two-part outer shape is placed in order to connect the end of the sleeve to the injected plastic in such a way that the package has been sprayed liquid-tight on its cover.

Liquid packs of this type and also other designs of liquid packs are known as disposable packs in increasingly used by the end consumer and therefore put on the market. The corresponding filling machines and also pack-making machines have to have a higher output, ie more packs have to be produced per unit of time and thus more sleeves have to be pushed onto mandrels and provided with end walls.

From the point of view of saving material, it has become common practice to make the sleeve walls thinner, which certainly does not simplify the handling and processing of the sleeve in the packaging production machine.

In the above-mentioned round pack with a square base and a round lid, the production is carried out in a machine in which the sleeve is first made flat and then passed between the mandrel and an ejector via a transport device, the sleeve coming from the flat in the round cross section is opened. As a result of the round cross section, it does not matter at which point on the circumference the longitudinal sealing seam, through which the flat web is formed to form the sleeve, is arranged.

In the meantime, attempts have also been made to produce square liquid packs in cross-section, sleeves also being used which are produced by attaching a longitudinal sealing seam, preferably a sealing seam with overlapping end regions.

In the manufacture of this cuboidal liquid pack, the base is made of the paper material itself by folding, while the cover is also molded on the opposite side and has the pouring device. The latter is arranged so that it shows with its pouring tip when looking at the top of the package from the lid to a corner thereof and is arranged in the vicinity thereof. For reasons of strength and so that the end user can grasp and handle the pack well, it also has to be partially highlighted when the longitudinal sealing seam is arranged on the adjacent side folding edge relative to the pouring opening. It can be easily imagined that the packing becomes stiffer due to the double-layered edge strips in the area of the longitudinal sealing seam. If you now use this stiff side folding edge as a point of attack for the end user, then the pack bends the least at this point, or dents or damage when gripping and pinching the pack between the thumb and the other four fingers of the hand are least to be feared here. Since the greatest pressure (greater than the four fingers) is applied to the package via the thumb, it is expedient if the side edge of the package sleeve comes to lie with the longitudinal sealing seam in such a way that the pouring device is arranged transversely to the top of the lid in such a way that that when pouring out the plane of the pouring jet runs through those two side folding edges, in one vicinity of which the tip of the pouring opening is arranged and in the other vicinity the four fingers of the user attack during pouring out, while the thumb sticks to the crosswise and stiffened by the longitudinal sealing seam Side folding edge of the sleeve attacks.

Taking these considerations into account in the manufacturing machine, difficulties arise, in particular in the case of a package with a quadrangular shape in cross section, in that the longitudinal sealing seam of the sleeve always wants to be guided to a certain edge of the mandrel even when the package manufacturing machine is performing well. In other words, the transport device for gripping the flat-lying sleeve and also the measures and devices for unfolding this sleeve must be designed in such a way that the longitudinal sealing seam always comes to lie at the desired location on the mandrel.

This consideration becomes particularly problematic when using two mandrel wheels at the same time, when sleeves are pushed onto two different mandrels one after the other, which are brought into a row after filling the plastic cover, filled, closed and transported away.

Even with packs produced in this way, the longitudinal sealing seams must always be in the same position.

The inventor has therefore set itself the task of improving the device for folding flat-lying sleeves of the type mentioned in such a way that it is possible with the new device to reliably clamp the flat-lying sleeve in a high cycle to a shape with a square cross-section, the The longitudinal seal seam always comes to a certain point.

This object is achieved according to the invention in that the transport device has a pivoting rocker arm which can be pivoted about an axis parallel to the linear movement direction of the ejector and has a centering web which can be pivoted about the axis by at least a quarter arc, the pivoted end position of which fixedly fastens a folding stop with V-shaped receiving surfaces is that in addition to the folding stop on both sides swivel levers with vacuum openings are pivotally provided such that two contact planes each delimiting a swivel lever span a V-shaped roof corresponding to two adjacent side faces of the unfolded sleeve, and that the ejector is provided on the front with a square plate and has a stroke , which is greater than the length of the pivoting lever, and which can be moved back and forth along the V-shaped contact planes, controlled synchronously with the pivoting movement of the distributor rocker. Surprisingly new is the design of the transport device as a pivotable distributor rocker which can be pivoted about an axis which runs parallel to the longitudinal direction of the mandrel on which the sleeve is to be pushed. This pushing on takes place via the linear movement of the ejector, which is why the pivot axis of the distributor rocker is arranged parallel to this linear direction of movement. The transport device transports a lower sleeve, which is moved out, for example, next to a magazine with a stack of flat-lying sleeves, along a quarter-circle arc into the position between the mandrel and ejector fer. When the sleeve is unfolded to its full square shape in this position, the ejector is switched on and pushes the sleeve onto the mandrel.

This unfolding of the sleeve from the initially almost flat-lying state into the quadrangular and preferably square state in cross-section now takes place according to the invention via a stationary folding stop which has V-shaped receiving surfaces in such a way that the wide opening of the V of the curved path of the distributor rocker is aligned .

One has to imagine the sleeve-shaped blank lying under the magazine so that the sleeve is flattened along two opposite folding edges, the longitudinal sealing seam in the cross section of the flat sleeve being arranged practically in the middle above it, so that the further folding line located next to the longitudinal sealing seam is practical unfolded is almost flat. The position of the longitudinal seal seam in the case of a horizontal, flat cut in the middle "above" between two "first" longitudinal folding edges is important. It has already been mentioned that in order to unfold the sleeve, fill and close the package by means of a mandrel and other stations in the packaging machine, the sleeve must always lie in the same position on the mandrel. If you look at the end face of the mandrel when the cut is initially lying flat in the horizontal plane, the quarter-round arc, ie the movement of the distributor rocker and the transport of the sleeve, bring the longitudinal sealing seam from the initially "upper" position to the "left""Position because the center of the quarter-circle arc, ie also the pivot axis of the distributor arm z. B. above the lowest flat-lying sleeve and - in this embodiment shown - to the left of the ready-to-use, considered mandrel. The quarter-circle arc is therefore practically a path that is comparable to the position of six to three in the clock. In the three o'clock position it is already slightly open cracked sleeve thus moved against the folding stop, so that its front of the two "first" longitudinal folding edges moved into the "downward" open V of the receiving surfaces of the folding stop and came to a stop.

So that not only the folding stop positions the sleeve and thus also supports the initially slightly cracked sleeve when it is unfolded into the cuboid final state, swivel levers are provided on both sides next to the folding stop, which can pivot about axes that are also parallel to the pivot axis of the Distribution rocker, parallel to the elongated folding stop and, for example, at its height next to it. Each pivoting lever has a bearing plane that points towards the space where the sleeve is to be unfolded, in which vacuum openings open in order to engage and possibly engage with the two side walls of the sleeve that lie next to the front "first" side folding edge To support unfolding by the respective plant level pulling up the adjacent side wall of the sleeve while spreading open. The two pivot levers with their contact levels are arranged next to the folding stop so that the contact levels, like the V-shaped receiving surfaces of the folding stop, also span a roof in a V-shape. As will be described later, this roof shape, again seen in a direction parallel to the pivot axis of the distributor rocker, is designed like a very pointed roof, and by pivoting open, e.g. of the left swivel lever clockwise from the seven to eight o'clock position and correspondingly on the opposite side of the other swivel lever from the five to four o'clock position, the V-shape of the roof spreads while the sleeve is unfolded. When spreading, the two side surfaces of the unfolded sleeve, which are separated by the foremost of the "first" longitudinal folding edges, are sucked onto the respective contact plane of the pivoting lever (and this on each pivoting lever).

If you continue to follow the path of the sleeve, it will become this sleeve fully unfolded into a cuboid pushed onto the square plate of the ejector on one side in that the ejector moves in the direction of its movement already mentioned, namely in the direction of the ready-to-shoot mandrel. During this movement of the ejector, the square plate first hits the square, rear edge of the sleeve, forms it and holds it. During this continuous movement of the ejector, the full stroke is traversed after the sleeve has been pushed onto the square plate, the sleeve passing under the V-shaped contact planes of the swivel levers, parallel to the longitudinal direction of the swivel levers and to the folding stop from the space under the folding stop and next to the swivel levers, is pushed onto the mandrel.

Finally, it is also mentioned above that the pivoting movement of the distributor rocker is controlled synchronously with this movement of the ejector. In a preferred embodiment of the unfolding device, namely after the front of the "first" side folding edges of the sleeve abuts against the folding stop, the distributor rocker supports the unfolding process by first delaying its movement in a controlled manner in synchronization with the movement of the pivoting levers (when the pivoting levers Have taken the clock or seven o'clock position and after opening the roof, ie moving the swivel lever to the four o'clock or eight o'clock position) and then moving a little further towards the folding stop, until the lower rear of the two "first" side fold edges of the sleeve is in its unfolded end position. When the ejector begins its pushing motion, the sleeve is held in the swivel levers by the vacuum, and the distributor arm can move the quarter-circle arc back to the starting position in order to take up the next isolated, flat-lying sleeve.

From the above brief description of the movement of the swinging arm, swivel levers and ejector you can see the simple structure and sequence of movements, so that the isolated, flat-lying sleeve is more reliable Can be stretched to a shape with a square cross-section, with the requirement that the longitudinal sealing seam always comes to lie at a certain point, for example in the exemplary embodiment considered, if you look at the end face of the ready-to-receive mandrel, to the left edge of the mandrel. It is provided that the parallelepiped mandrel is arranged diagonally, so to speak, that is, the planes through its longitudinal outer edges lie horizontally and vertically (in contrast to the "straight" arrangement of a cuboid, in which the diagonals running through the cross-sections spanning the cross-section are not horizontal and vertical but lie diagonally to it.)

The invention is further advantageously embodied in that the distributor rocker arm has an arm and at the radially outer end thereof a part-cylindrical holding plate, that a centering web with a V-shaped upwardly projecting receiving surface is attached to at least one straight end edge of the holding plate, and that a part-cylinder-shaped one Basket is attached stationary next to the path of movement of the holding plate. The arm of the distributor rocker is to be thought of as a connecting element between its pivot axis on the one hand and at arm's length spaced therefrom, on the other hand the holding plate. The retaining plate is curved in the direction of the pivot axis of the distributor rocker, with one straight end edge at one end of the curve and the other edge at the other end of the curve. An elongated centering bar with the mentioned receiving surfaces is arranged on at least one end channel, because in the sense of the above-mentioned exemplary embodiment, the rear of the two "first" longitudinal folding edges of the still-lying sleeve is received by this centering bar in one position, for example, when it is an eight o'clock Has taken position and then runs through its quarter-circle arc to the four o'clock or three o'clock position in order to move the flat-lying sleeve from the position under the magazine into the position against the folding stop in an arc. This movement slides the more or less flat sleeve on the part-cylinder-shaped basket, which is arranged close to the path of movement of the centering bar.

It is expedient according to the invention if the stationary folding stop is in the form of a strip which is longer than the sleeve to be unfolded and approximately as long as the pivot lever in the axial direction. The V-shaped receiving surfaces of the folding stop can thus accommodate the entire front of the "first" longitudinal folding edges of the sleeve, which makes the guidance particularly reliable both before and during the receiving of the sleeve and during the unfolding process.

In an expedient embodiment of the invention, the contact plane of the respective pivot lever has recesses in which stationary rollers can be received. The rollers serve to guide the unfolded sleeve when the ejector moves outward. The rollers are rotatable about their longitudinal axes, but are otherwise immovably stationary on both sides under the folding stop in such a way that they each form a tangentially arranged guide plane. Both management levels then in turn span the desired V-shaped roof corresponding to the two side faces of the unfolded sleeve lying next to one another. The swivel levers are movable in relation to the stationary rollers, i.e. the recesses move like gates over the rollers when the swivel levers move. In cross-section, the contact levels of the swivel levers can span a much more pointed V in the starting position and a blunt or flatter V in their end position than the V that the rollers span. The latter is generally rectangular.

It is furthermore advantageous according to the invention if a guide spanning a square corresponding to the cross-section of the sleeve is stationary on the side of the folding stop facing the mandrel of the machine. This guide can be formed, for example, by four elongated rollers or alternatively also stationary sliding bodies on which the unfolded sleeve is pushed by the ejector out of the room under the folding stop onto the mandrel. The particular advantage of this leadership is its leadership function, as the name says. If the ejector has received and held the rear end of the unfolded sleeve with its square plate, the front end of the square unfolded sleeve already comes into the guide after a short time during the movement of the ejector and is held by it. In this way, the sleeve is held at the beginning and the back of the ejector movement on its square edges, namely on the one hand by the guide just mentioned and on the other hand the square plate of the ejector. Advantageously, the pivot levers can then be opened to form the very open or blunt V, so that the sleeve is only guided by the rollers as it continues to advance under the stationary folding stop. Rolling friction prevents damage to the outer surface of the sleeve when it is pushed out.

The invention is further advantageously configured in that the ejector has a cup-shaped housing in which the square plate is resiliently biased against the cup base and is arranged such that it can be moved linearly and at a distance from it, and that the edge of the square plate corresponding to the circumferential contour of the unfolded sleeve is slanted inside. The latter feature, like a cone, promotes the attachment of the rear edge of the sleeve to the square plate when the ejector begins its outward movement. The resilient mounting of the square plate, on the other hand, has the advantage that the ejector can move up to the face of the mandrel without damage and, moreover, can even push the sleeve far enough onto the mandrel. The square plate, which can be made of plastic, for example, preferably moves within the cup-shaped housing, which is preferably made of steel, so that in one position the square plate protrudes the most from the ejector to the front and therefore first with the End face of the mandrel comes into contact; after belching on the end face of the mandrel, however remains relative to the cup-shaped housing. This housing and in particular its cylindrical side walls (of the cup) then move relative to the square plate seated on the end face of the mandrel and, during this relative movement, push the sleeve which has already been partially pushed onto the mandrel even further onto the mandrel, so that the trailing edge of the sleeve is practical comes to lie at a distance from the end edge of the mandrel. This is desirable and serves for the correct positioning of this rear sleeve edge, on which the plastic cover on the mandrel is then to be injection molded later.

It is also advantageous according to the invention if a raised ring made of elastomeric material is embedded in the front end plane of the square plate. The opening of the ejector and in particular its square plate on the end face of the mandrel is raised by such. Damped ring, which can preferably be made of rubber. Its ring surface can form a substantial part of the cross-sectional area of the sleeve and therefore form good storage and shock absorption for the ejector.

In the imaginary exemplary embodiment described above, it has so far only ever been assumed that only one mandrel is to be loaded with sleeves and that the individual sleeve located under the magazine is practically only on one side of the distributor rocker, namely via a quarter-circle arc between the seven O'clock to the three o'clock position. In order to increase the performance and the work cycle of a packaging manufacturing machine, two mandrel wheels can also be arranged and plastic lids can be injected onto two mandrels at the same time in order to make better use of the processing time in the packaging machine. It takes more time to inject the lid onto the sleeve (until the lid has hardened) than to fill and close the base by folding. So a machine has been made more powerful in that the filling and closing stations of the packing machine have two mandrels be worried. However, this also entails placing sleeves on two mandrels in such a way that after the sleeves have been inserted, for example, from the additional, second "left" mandrel into the row of sleeves still provided with gaps from the "right" mandrel already described above Sleeves are always arranged in the same position with respect to their longitudinal sealing seam.

To meet these conditions, it is proposed according to the invention to arrange the two mandrels on opposite sides with respect to the distributor rocker and thus also with respect to the sleeve magazine on opposite sides and to feed the sleeves to the left mandrel in a position shifted by 180 °, so that on the first or right one Mandrel the longitudinal folding edge comes to rest, for example, on the left most edge, while on the second or left mandrel this longitudinal sealing seam of the sleeve comes to rest on the rightmost edge of the mandrel. This rotation by 180 ° is necessary because the packing of the packs from the second or left mandrel takes place in an arc-shaped movement, in which the sleeve or sleeve with the lid is rotated by 180 °, so that after the packing actually all sleeves both of the first and that of the second mandrel all have the longitudinal sealing seam on the same side.

For this purpose, it is advantageous according to the invention if the distributor rocker arm has two opposing centering webs and is arranged to be pivotable approximately semicircularly approximately centrally between two folding stops with pivoting levers. During operation, the distributor rocker with its centering bar, which is attached to the other straight end edge of the retaining plate, for example, pushes the next isolated, almost flat-lying sleeve clockwise on a further four-part circular arc into the position between the one on the return stroke from the position of the first right mandrel second left mandrel and a second ejector. After the sleeve has been applied to the first right mandrel in the end position and the cover has already been molded there, work on the second Left mandrel just the ejector and pushes the next sleeve in the correct position on the second mandrel. The work cycle when the machine is doubled is clearly improved by the arrangement of two mandrel gears.

• Figur 1 eine vertikale Querschnittsansicht durch die Auffalt­einrichtung mit Schwenkhebeln, stationären Rollen, einem abgebrochen dargestellten Teil der Verteiler­schwinge der Hülse und in Draufsicht des Auswerfers, und zwar in einer ersten Position kurz nach dem Ein­schieben der erst teilweise aufgesprungenen Hülse,
• Figur 2 eine ähnliche Darstellung wie Figur 1, wobei jedoch die Hülse bereits in ihrem vollständig aufgefalteten Zustand dargestellt ist,
• Figur 3 einen Längsschnitt durch die Auffalteinrichtung, etwa durch die vertikale Mittellinie der Figur 2 mit dem Antrieb für die Schwenkhebel,
• Figur 4 eine ähliche Ansicht wie Figur 1, wobei jedoch eine andere Ausführungsform mit Schwenkhebeln ohne statio­näre Rollen gezeigt ist,
• Figur 5 eine Ansicht entsprechend der Figur 3, jedoch bei der Ausführungsform der Figur 4 ohne die stationären Rol­len,
• Figur 6 eine Ansicht der Verteilerschwinge in Richtung ihrer Schwenkachse,
• Figur 7 eine Ansicht der Verteilerschwinge entlang der Linie VII-VII in Figur 6,
• Figur 8 eine Draufsicht auf den bogenförmig ausgestalteten Korb, der in Figur 6 lediglich abgebrochen unten rechts angedeutet ist,
• Figur 9 eine Draufsicht auf den Korb der Figur 8,
• Figur 10 eine Seitenansicht des Auswerfers mit abgebrochen angedeutetem Antriebshebel,
• Figur 11 eine Draufsicht auf die Stirnfläche der Vierkant­platte mit dem erhabenen Ring aus Gummi,
• Figur 12 eine Draufsicht auf die Führung, die in den Figuren 3 und 5 links in der Seitenansicht dargestellt ist, und
• Figur 13 eine Querschnittsansicht durch den Rahmen der Auf­falteinrichtung ohne Auswerfer und ohne Schwenkhe­bel.

Further advantages, features and possible applications of the present invention result from the following description of preferred exemplary embodiments in conjunction with the attached drawings.

• FIG. 1 shows a vertical cross-sectional view through the unfolding device with swivel levers, stationary rollers, a part of the distributor rocker of the sleeve shown broken away, and a top view of the ejector, in a first position shortly after the sleeve, which has only partially opened, is inserted,
• FIG. 2 shows a representation similar to FIG. 1, but with the sleeve already shown in its fully unfolded state,
• FIG. 3 shows a longitudinal section through the unfolding device, approximately through the vertical center line of FIG. 2 with the drive for the swivel levers,
• FIG. 4 shows a view similar to FIG. 1, but showing another embodiment with pivot levers without stationary rollers,
• 5 shows a view corresponding to FIG. 3, but in the embodiment of FIG. 4 without the stationary rollers,
• FIG. 6 shows a view of the distributor rocker in the direction of its pivot axis,
• FIG. 7 shows a view of the distributor rocker along the line VII-VII in FIG. 6,
• FIG. 8 shows a top view of the arched basket, which is indicated only broken off in FIG. 6 at the bottom right,
• FIG. 9 shows a top view of the basket of FIG. 8,
• FIG. 10 shows a side view of the ejector with the drive lever indicated broken off,
• FIG. 11 shows a plan view of the end face of the square plate with the raised ring made of rubber,
• Figure 12 is a plan view of the guide, which is shown in Figures 3 and 5 on the left in the side view, and
• Figure 13 is a cross-sectional view through the frame of the unfolding device without ejector and without pivoting lever.

In the embodiment described below, it is assumed that the distributor rocker arm is arranged “above” the basket and somewhat below and approximately in the middle between two mandrel gears, with “first right” the first mandrel gear and “above left” the second mandrel gear The flat-lying sleeve is pushed in an arc from the position in the middle "below" to "above" under the folding stop. Nevertheless, it is understood by the person skilled in the art that, with a correspondingly different arrangement, both the sides and the top and bottom are interchangeable. Reference is only made to "above" and "below" in the sense suggested above for easier description and better understanding.

In Figure 7, the magazine 1 is shown with flat-lying paper sleeves 2, which consist of paper material coated with plastic. One looks straight at the front right of the "first" longitudinal folding edges of the sleeve 2, which is denoted by 3 in the cross-sectional representations (FIGS. 6 and 8), while the longitudinal sealing seam of the sleeve 2 is denoted by 4.

In FIGS. 1, 2 and 4 one can see the frame 5 drawn out in detail in FIG. To simplify the drawings, only the right-hand work station seen in the push-on direction of the sleeves 2 is shown, the compartment but one also has to think of a left station as a mirror image of the main middle level. Therefore, in the right station shown here, the frame 5 has rails 6 on its left side, which serve to guide the ejector to be described later, which is generally designated 7 and is shown in more detail in connection with FIGS. 10 and 11.

The flat-lying sleeve 2 is to be guided by the transport device, generally designated 8, into the position in which the sleeve 2 is arranged in the illustration in FIGS. 1 and 2. One looks at the ejector 7 in the axial direction of the mandrel 9 (shown at the top right in FIG. 8).

On the frame 5, a folding stop 10 with V-shaped receiving surfaces 11 is fastened in the form of a strip which is longer than the sleeve 2. On both sides at the level of the folding stop 10, there are the axes of rotation 12 of pivot levers 13. In a first embodiment, as shown in FIG. 3, one looks at a contact plane 14, in which recesses 15 are provided, in order to accommodate rollers 16 arranged in a stationary and rotatable manner. A sectional view of this arrangement is shown in Figures 1 and 2, on the right with a view of the rollers 16 according to section line II and the left on the lever 13 (next to the rollers) according to section line I'-I 'of Figure 3. The pivot lever 13 are driven via an air cylinder 17 and generally designated 18 drive levers pivotable about the axes 12. The air cylinder is only necessary for the separate control in the embodiment according to FIGS. 1 to 3, in the illustration of FIGS. 4 and 5 the air cylinder is omitted, but not the drive levers 18, which are controlled synchronously by the drive of the distributor rocker arm 20 in the second embodiment , which is shown in Figures 6 and 7 (transport device).

According to Figure 1, the pivot levers 13 are in a position in which the contact planes 14 form an acute V. and the sleeve 2 with the longitudinal sealing seam arranged on the left is only shown in a slightly popped-up state.

Parallel to the viewing direction of Figures 1 and 2, i.e. perpendicular to the plane of the paper, in addition to the longitudinal central axis 21 of the mandrels 9, 9 '(FIG. 8), the axis of rotation 12 of the pivoting levers 13 and the linear movement direction of the ejector 7 running along the axis 22 also run parallel, namely in the direction of the rails 6 The direction is also the longitudinal axis of the strip-shaped folding stop 10 and the longitudinal direction of the frame 5.

In FIG. 3, the larger, approximately left central part of the folding space is shown under the folding stop 10 with the contact plane 14 and the rollers 16, the ejector 7 is indicated in the right third in the frame 5 and the one generally designated 23 on the side of the folding space opposite this Guide, which is shown in Figure 12 in plan view.

One can also see in FIG. 3 the vacuum openings 24 and the vacuum pipe connections 25 in the part cut off at the top right and left as well as in FIGS. 1 and 2 the vacuum connecting pipes 26 between these vacuum lines 25 running parallel to the axes of rotation 12 and the openings 24 4 and 5, the vacuum openings 24 are visible with the only difference that the stationary rollers 16 are not present in FIGS. 4 and 5.

The ejector will now be described.

Its direction of movement thus runs according to line 22 in FIGS. 3 and 5 or point 22 in FIGS. 1, 2 and 4. This direction of movement 22 is predetermined by the rails 6, which run in the same direction. In these rails 6 run four rollers 28 rotatably mounted on a carriage 27. The carriage 27 is connected to the lever arm 29 with the Housing 30 of the ejector 7 connected.

With reference to FIG. 10, it can be seen that the steel housing 30 has the shape of a cup with cylindrical jacket-shaped side walls 31, an axial bearing at 32 and recesses 33 for springs 34 which, compared to the steel housing 30, have a square plate 35 made of plastic at a distance d from the bottom 36 keep the housing biased. The end face 37 of the square plate 35 has a raised ring 38 made of rubber. Along the circumferential contour, the edge 39 of the square plate 35 is inclined inwards. In the illustration in FIG. 4, the sleeve 2 can also be seen with its rear edge 40, which, in addition to the beveling of the edge 39 of the square plate 35, bears on the annular end face of the cylindrical jacket-shaped side wall 31 of the steel housing 30.

In the small broken sectional view under Figure 10 on the left you can see the front end of the mandrel 9 with its longitudinal axis 21 and end face 41 with the sleeve 2 pushed on, the rear edge 40 of the ejector 7 is pushed a little further back onto the mandrel 9 than it is without the resiliently mounted square plate 35 would be possible. The distance d in FIG. 10 also shows the distance in the broken representation in FIG. 10 at the bottom left again, by which the rear edge 40 of the sleeve 2 is pushed past the front end face 41 of the mandrel 9 backwards onto the mandrel.

The leadership 23

This guide 23 is shown in FIG. 12 and attached to the plate 42. In this illustration, there are four rollers 44 rotatably supported via bearings 43, which are arranged in the square so that the sleeve 2 is in contact with the respective inner line of the rollers 44 in the unfolded state and is thus held square. In the illustration of the figures, the cross section of the unfolded sleeve 2 is a square.

The distributor arm

The distributor rocker is shown in FIGS. 6 and 7 and designated 20. It has an arm 50 which carries a holding plate 51 via screws 52 and makes it pivotable about the axis 53 via the ball bearing 54 'shown at the top right in FIG. While the arm 50 of the distributor rocker 20 runs rectilinearly along a radius, surrounds the pivot axis 53 and pushes against the holding plate 51 and widens in an L-shape, as shown in FIG. 7, the holding plate 51 has the shape of a partial cylinder jacket surface with two curved ones Edges 54 ′ in FIG. 7 on the right and left or in FIG. 6 in front the curved double line; and two straight end edges 55, the end points on the right and left in FIG. 6 and the straight double line in FIG. 7. Centering webs 56 are provided on both straight end edges 55 of the holding plate 51 and are provided with receiving surfaces 57 which are V-shaped in cross-section to the outside (right and left). The centering webs 56 have the length of the straight end edge 55 and thus also last shape. Their length is approximately equal to the length of the sleeve 2 and thus also approximately equal to the length of the folding stop 10.

A partially cylindrical jacket-shaped basket 60 shown in FIGS. 8 and 9 in side view and plan view, which also belongs to the transport device 8, is formed from bent rods 61 and four support bolts 62 [arranged transverse to these parallel rods 60]. The basket stands firmly on the floor on the stationary supports 63 indicated in FIG. FIG. 7 also shows the rods 61 which are arranged in an arc and parallel and at a distance from one another and are square in cross section, which form the basket 60, which is also indicated in FIG. 6 on the right. Two small guide plates 63 ensure that the sleeve 2 shown on the right in FIG. 8 is in contact on the upper side in FIG. 9 as a guide for the movement path of the sleeve 2 during the four-part arc movement of the distributor rocker 20 according to FIG. 8 from the six o'clock to the three o'clock position. Clock position.

In operation, the sleeve 2 in the magazine 1 shown in FIG. 7 initially lies flat on the bottom on the arcuate square rods 61 of the basket 60, the longitudinal sealing seam 4 being arranged at the top. After separation, the flat-lying sleeve 2 has cracked slightly, so that its cross section has the shape of a rhombus. The so-called "first" side fold edges are strongly folded, and in FIG. 6 one can see the right front longitudinal fold edge 3, while the other two opposite fold edges, one of which is arranged next to the longitudinal sealing seam 4, are weakly or almost not folded. In this state, the V-shaped mounting surface 57 grips the left tip of the sleeve 2 when the arm 50 of the distributor rocker 20 has reached approximately an eight o'clock or seven o'clock position and its oscillating movement begins in the counterclockwise direction. If the distributor rocker 20 has reached its six o'clock position exactly, as shown in FIG. 6, then it has already pushed the sleeve 2, which is still partially flat, a bit in front of itself, and this movement continues until the state of FIG. 1 is reached.

In Figure 1, the two pivot levers 13 are still quite close together, so that their contact levels 14 span a very pointed roof, the V of which only encloses a small angle. The centering web 56 has now reached the position shown in FIG. 1 because the front side folding edge 3 of the sleeve 2 has just reached the tip of the V of the folding stop 10 between the receiving surfaces 11. The pivot levers 13 can, as is particularly clearly shown in FIG. 4, have funnel-shaped bevels 70 in their lower area, so that the front side folding edge 3 of the sleeve 2 can be pushed well into the V-shaped space as far as under the folding stop 10. At this moment, the contact planes 14 with the vacuum openings 13 bear against the two opposite side surfaces 71 and 72 of the sleeve 2, which are also connected to one another via the side folding edge 3. The control switches on the vacuum so that these side surfaces 71, 72 lying side by side from the swivel arm beln 13 are kept sucked.

Now the unfolding process is initiated, because with further arcuate movement of the distributor rocker 20 and thus its centering web 6 upwards in FIG. 1, the position of FIG. 1 is now left in order to maintain the position and unfolding shape according to FIG. The swivel levers 13 move apart by increasing the angle of the contact planes 14 between them until the centering web of the distributor rocker 20 has reached the position denoted by 56 'in FIG. 2. In this position, the sleeve 2 has also reached its square shape (in cross section). The sleeve 2 is now with its side wall 71 on the contact plane 14 of the left pivot lever 13, if you consider the section line I'-I 'of Figure 3 and on the opposite side of the stationary roller 16, if you take the section II of Figure 3 considered.

In the further pivoting of the pivot lever 13 in the sense of increasing the angle, which is included by their contact planes 14, the sleeve comes with its side surfaces 71 and 72 in contact with the rollers 16, while the centering web 56 from its position 56 'down again is moved and while the ejector 7 also begins its movement from the position shown on the right in FIG. 3 to the left.

The sleeve has a rear edge 40 which first comes into engagement with and is held by the square 35 of the ejector 7, as shown on the left in FIG.

As the ejector 7 moves further to the left in the illustration in FIG. 3, the front edge opposite the rear edge 40 of the sleeve 2 is understandably inserted into the guide 23, so that the sleeve 2 is now held in the front by the sleeve 23 and in the rear by the square plate 35 is. It is therefore no longer necessary to support the edge of the sleeve 2 opposite the side folding edge 3 by means of the centering web 56, which is why this is done when the Distributor arm 20 is moved clockwise in the other direction.

The ejector 7 has meanwhile already pushed the sleeve 2 onto the mandrel 9, and now the rubber ring 38 of the ejector 7 comes into engagement with the end face 41 of the mandrel 9, so that the cylindrical side wall 31 of the steel housing 30 pushes the trailing edge 40 of the sleeve 2 forward while squeezing the springs 34, the square plate 35 remains in the housing 30 because it is supported by the front end face 41 of the mandrel 9. This pushing movement takes place along the distance d, as can be seen from FIG. 10 and the broken-off small view below.

The ejector 7 has now carried out its forward stroke, which is longer than the length L of the pivot levers 13 in FIG. 3.

In the meantime, the distributor rocker 20 with the left centering web 56 and the receiving surfaces 57 had taken hold of the next isolated, almost flat-lying sleeve 2, which, with the further rotational movement clockwise about the axis 53, moved in an arcuate manner to the left (FIG. 8) in the direction of the Position between the other ejector, not shown, and the mandrel 9 'takes place. In the meantime, the pivot levers 13 have moved from the position of the spread V back over the position of FIG. 2 to that of FIG. 1. While now, according to FIG. 8, the sleeve 2 is pushed onto the mandrel 9 'on the upper left side, the next isolated sleeve 2 is gripped again and pushed onto the right mandrel 9, so that the play described above from the position of FIG. 1 is repeated starting.

In the embodiment according to FIGS. 4 and 5, the operation is the same, except that to simplify the machine the stationary rollers 16 are omitted and the contact planes 14 of the pivot levers 13 are only interrupted by the vacuum openings 24, otherwise they are smooth, flat surfaces. The control of the swivel lever is carried out synchronously via not Darge provided drive means for pivoting the distributor rocker 20, so that the air cylinder 17 in the embodiment according to FIG. 3 is missing here in the embodiment in FIG. 5.

Claims (8)

1. Device for unfolding flat sleeves (2) made of paper, cardboard or the like, with longitudinal sealing seam (4), in particular for the production of liquid packs, with a transport device (8) for gripping the flat sleeve (2) and insertion into a position axially aligned between a mandrel (9, 9 ′) and an ejector (7), characterized in that the transport device (8) has a distributor rocker arm (53) which can be pivoted about an axis (53) lying parallel to the linear direction of movement (22) of the ejector (7). 20) with a centering web (56) which can be swiveled around the axis (53) at least by a quarter circular arc, the pivoted out end position of which is fixed in a stationary manner opposite a folding stop (10) with V-shaped receiving surfaces (11) which, in addition to the folding stop (10) Swivel levers (13) with vacuum openings (24) are pivotable on both sides such that two contact planes (14) which each delimit a swivel lever (13) n V-shaped roof according to two side surfaces (71, 72) of the unfolded sleeve (2), and that the ejector (7) is provided on the front with a square plate (35) has a stroke that is greater than the length (L ) the pivot lever (13), and which can be moved back and forth along the V-shaped bearing planes (14), synchronously with the pivoting movement of the distributor rocker (20). 2. Apparatus according to claim 1, characterized in that the distributor rocker (20) has an arm (50) and at its radially outer end a part-cylindrical holding plate (51) that on at least one straight end edge of the holding plate (51) has a centering web (56 ) with cross-sectionally V-shaped receiving surfaces (57) is fixed and that a part-cylinder-shaped basket (60) stationary next to the path of movement of the retaining plate ches (51) is attached (Figures 6 to 8). 3. Apparatus according to claim 1 or 2, characterized in that the stationary folding stop (10) has the shape of a bar which is longer than the sleeve to be unfolded (2) and approximately as long as the pivot lever (13) in the axial direction (12) is. 4. Device according to one of claims 1 to 3, characterized in that the contact plane (14) of the pivot lever (13) has recesses (15) in which stationary rollers (16) can be received (Figure 3). 5. Device according to one of claims 1 to 4, characterized in that on the mandrel (9, 9 ') facing the machine side of the folding stop (10) a square corresponding to the cross section of the sleeve (2) spanning guide (23) is stationary (Figures 1 and 12). 6. Device according to one of claims 1 to 5, characterized in that the ejector (7) has a cup-shaped housing (30) in which the square plate (35) against the cup base (36) is resiliently biased and at a distance (d) from this and is linearly movable, and that the peripheral contour of the unfolded sleeve (2) corresponding edge (39) of the square plate (35) is inclined inwards. 7. Device according to one of claims 1 to 6, characterized in that a raised ring (38) made of elastomeric material is embedded in the front end plane (37) of the square plate (35). 8. Device according to one of claims 1 to 7, characterized in that the distributor rocker (20) has two opposite centering webs (56) and approximately in the middle between two folding stops (10) with pivoting levers (13) is arranged to be pivotable almost semicircularly.

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