EP0328876B1 - Device for unfolding tubes lying flat - Google Patents

Description

The invention relates to a device for unfolding flat-lying sleeves made of paper, cardboard or the like with a longitudinal sealed seam, in particular for the production of liquid packs, with a transport device for gripping the flat-lying sleeves and inserting them into a sliding guide axially in alignment between a mandrel and a slide, the transport device a rocker which can be pivoted about an axis parallel to the linear direction of movement of the pusher, the sliding guide has a stationary fixed folding stop with V-shaped receiving surfaces and the pusher is provided on the front with a plate, has a stroke which is greater than the length of the sliding guide and controlled synchronously with the pivoting movement of the rocker, can be moved back and forth.

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 are known which have 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, ie thus 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 used as disposable packs to an ever greater extent by the end user and are therefore brought onto the market. The corresponding filling machines and also packaging production machines must have a higher performance, i.e. more packages 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 of the sleeve and its processing in the packaging 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 production of this cuboid liquid pack, the base is made of the paper material itself by folding, while on the opposite side the cover is also injection molded into a square shape and has the pouring device. The latter is arranged in such a way that with its pouring tip, when the plan view is viewed from above, from the lid to a corner shows the same and is arranged in the vicinity. For reasons of strength and thus the end user can grasp and handle the pack well, it has also proven to be advantageous if the longitudinal sealing seam is arranged on the adjacent side folding edge relative to the pouring opening. It is easy to imagine that the packing becomes stiffer due to the double-layered edge strips in the area of the longitudinal seal. If you now use this stiff side folding edge as a point of attack for the end user, then the package bends the least at this point, or dents or damage when the package is gripped and clamped 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 in 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 rest on the mandrel at the desired location.

This consideration becomes particularly problematic when using two mandrel gears simultaneously, if on two different ones Thorns are pushed onto the sleeves one after the other. After the plastic cover has been molded on, they are brought into a row, filled, sealed and transported away. Even with packs produced in this way, the longitudinal sealing seams must always be in the same position.

From US-A-2,357,535 a folding device of the type mentioned above in the introductory part is known. There, paper tubes lying flat are removed from a magazine by means of air suction devices attached to two rockers and guided around a quarter-circle arc to form a kind of sliding guide in the form of two mutually perpendicular walls. The corner between the two walls can be seen as a kind of folding stop with V-shaped receiving surfaces, because in this sliding guide the paper sleeve then unfolded is held by the suction cups until the pusher engages. On the way from the position under the magazine to the sliding guide, the paper sleeves run against stops, with the help of which the free end of the paper sleeves, which is opposite the holder with the suction cups, is grasped and folded and folded over with the air suction cups when the rocker is piled up is that the fold is overstretched from the original flattened position with the purpose that after the springback it is expected that the paper tube will then be approximately in the desired erected position.

This unfolding process does not succeed with perfect reliability without errors and can only be carried out with paper cores in which the longitudinal sealing seam is located directly next to a folding edge. The material of the paper sleeves also plays a role, because there is a risk in the known unfolding device that the paper sleeve is not folded but folded over with double walls.

This danger had already been recognized in the unfolding of paper sleeves, because a folding device is known from DE-B-1,124,799, in which paper sleeves, in turn, are drawn off from a magazine via suction cups and guided straight to a folding device transversely to the suction movement. There, the paper sleeve, which is still lying together, is guided with its front edge against a folding stop which lies in the articulation axis of a pivotable double arm. Each of the two arms in turn carries suction cups, which move synchronously under control to the opposite sides of the folded paper sleeve and not only unfold them but overstretch them similarly to the previously known device, so that the paper sleeve assumes a folded state again, but this time with the other two Opposing surfaces, i.e. in the transverse direction. In a third station, the paper sleeve, which is thus kept overstretched, must again be used be transported straight to the corner of a trolley, where it is hoped that the paper tube will then spring open properly and be held in the trolley on the moving conveyor belt for further processing. The latter device is complex and also not designed with the desired reliability,

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

This object is achieved in that the rocker has a centering jaw at its end engaging the sleeve and can be pivoted along a stationary, part-cylinder jacket-shaped guide, that the pivoted end position of the centering jaw is attached opposite the folding stop, next to which swivel levers with vacuum openings are pivotally provided on both sides are that two respective planes delimiting a swivel lever span a V-shaped roof corresponding to two adjacent side faces of the unfolded sleeve, and that the plate of the pusher designed as a square plate is movable along the V-shaped planes.

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 the pusher. When the sleeve is unfolded into its completely square shape in this position, the pusher is switched on and pushes the sleeve on the thorn.

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 separate stationary folding stop which bears V-shaped receiving surfaces in such a way that the wide opening of the V aligns the arch path of the rocker is.

One has to imagine the sleeve-shaped blank so isolated under the magazine that the sleeve along two opposite folding edges is flattened, 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 practically still unfolded. 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 blank is initially lying in a horizontal plane, the quarter-round arc, ie the movement of the rocker arm 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, ie also the pivot axis of the
Swing arm is arranged, for example, over the lowest, flat-lying sleeve and - in this exemplary embodiment presented - to the left of the mandrel that is just ready to be taken into consideration. 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, the sleeve, which has already cracked open, has thus moved against the folding stop, so that its front of the two "first" longitudinal folding edges has entered the open "downward" V of the receiving surfaces of the folding stop and has come to a stop.

So that not only the folding stop is responsible for the positioning of the sleeve and thus also a support for the initially slightly cracked sleeve when it is unfolded into the cuboid end state, swivel levers are provided on both sides next to the folding stop, which can pivot about axes which are also parallel to the pivot axis of the Swing arm, lying parallel to the elongated folding stop and, for example, at its height next to it. Each pivot lever has one facing the space where the sleeve to be unfolded, a contact plane, in which vacuum openings open, in order to come into engagement with the two side walls of the sleeve, which lie next to the front "first" side folding edge and, if necessary, to support unfolding by the respective contact plane the adjacent side wall of the Pull up the sleeve while spreading. 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 rocker, is designed like a very pointed roof, and by pivoting open, e.g. the left pivot lever clockwise from the position 7 a.m. to 8 a.m. and accordingly on the Opposite side of the other swivel lever from the five o'clock 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, this sleeve, which has been completely folded into a cuboid, is now pushed onto the square plate of the pusher on one side in that the pusher moves in the direction of its aforementioned movement, namely in the direction of the ready-to-take-up mandrel. During this movement of the pusher, the square plate first hits the square, rear edge of the sleeve, forms it and holds it. During this continuous movement of the pusher, 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 pivoting levers, namely parallel to the longitudinal direction of the pivoting 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 rocker is also controlled synchronously with this movement of the pusher. In a preferred embodiment of the unfolding device, the rocker supports the unfolding process after the front of the "first" side folding edges of the sleeve abuts against the folding stop by first delaying its movement in a manner controlled by the movement of the pivoting levers (when the pivoting lever Have taken the clock or seven o'clock position and after opening the roof, ie moving the swivel lever into 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 pusher begins its pushing motion, the sleeve is held in the swivel levers by the vacuum, and the rocker can move the quarter-circle arc back to the starting position in order to pick up the next isolated, flat-lying sleeve.

From the above brief description of the movement of the swing arm, swivel levers and pushers you can see the simple structure and sequence of movements, so that the initially isolated, flat-lying sleeve can be reliably stretched to a shape with a square cross-section, with the requirement that the longitudinal seal seam always comes to a certain point, for example, in the exemplary embodiment considered, when 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 rocker arm has an arm and at the radially outer end thereof a part-cylindrical holding plate, that a centering mouth with V-shaped receiving surfaces projecting outwards in cross section is fastened to at least one straight end edge of the holding plate and that the part-cylinder-shaped Sliding guide designed as a basket and stationary next to the path of movement of the retaining plate is attached. The arm of the rocker is to be thought of as a connecting element between its pivot axis on the one hand and at arm's length from it, the holding plate on the other. The retaining plate is curved in the direction of the pivot axis of the 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 jaw with the receiving surfaces mentioned 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 in one position by this centering jaw when, for example, 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. During this movement, the more or less flat sleeve slides on the part-cylinder-shaped basket, which is arranged close to the path of movement of the centering jaw.

According to one embodiment of the invention, it is expedient if the stationary folding stop has the shape of a strip which is longer than the sleeve to be unfolded and is approximately as long as the pivoting 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 a further 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 side by side. 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 planes 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.

According to a further embodiment of the invention, it is also advantageous 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 out of the space under the folding stop onto the mandrel by the pusher. The particular advantage of this leadership is its leadership function, as the name says. If the pusher has received and held the rear end of the unfolded sleeve with its square plate, then the front end of the square-unfolded sleeve comes into the guide after a short time during the movement of the pusher and is held by it. In this way, the sleeve is already supported at the front and rear at its square edges at the beginning of the sliding movement, namely on the one hand by the guide just mentioned and on the other hand the square plate of the pushing device. The swivel levers can then advantageously be used to form the very open or open the 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 slide 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 in 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 sleeve edge to the square plate when the pusher begins its outward movement. The resilient mounting of the square plate on the other hand has the advantage that the slide can move up to the front 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 farthest from the pusher and therefore first with the End face of the mandrel comes into contact; after encountering 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.

According to one embodiment of the invention, it is also expedient if a raised ring made of elastomeric material is embedded in the front end plane of the square plate. The opening of the pusher and in particular its square plate on the end face of the mandrel is damped by such a raised 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 pushing device.

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 practically the individual sleeve located under the magazine is practically only on one side of the 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. A machine has therefore been made more powerful in that the filling and closing stations of the packaging machine are supplied by two mandrels. However, this also entails placing sleeves on two mandrels in such a way that, after the sleeves have been inserted, e.g. from the additional, second "left" mandrel into the row of sleeves still provided with gaps from the "right" mandrel already described above, the sleeves are always arranged in the same position with respect to their longitudinal sealing seam.

In order to meet these conditions, it is proposed according to one exemplary embodiment to arrange the two mandrels on opposite sides with respect to the 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 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 right-most 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. The swing arm has now been given a distribution function.

For this purpose, it is advantageous if the rocker is designed as a distributor rocker and has two opposing centering jaws and is arranged to be pivotable approximately semicircularly approximately between two folding stops with a pivoting lever and if the basket-shaped sliding guide is preferably designed in the shape of a semi-cylinder. In operation, the distributor rocker with its centering jaw, which is attached to the other straight end edge of the retaining plate, for example, pushes the next isolated, almost still lying sleeve clockwise on a further four-part arc into the position between the one when it returns from the position of the first right mandrel in a clockwise direction second left mandrel and a second pusher. After the sleeve has been applied to the first right mandrel in the end position and the cover has already been molded on, the pusher on the second left mandrel is just working and pushes the next sleeve in the correct position onto 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 Schwinge der Hülse und in Draufsicht des Überschiebers, 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 ähnliche 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 Überschiebers 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 Überschieber und ohne Schwenkhebel.

Further advantages and possible uses of the present invention result from the following description of preferred exemplary embodiments in conjunction with the attached drawings. Show it:

Figure 1

3 shows a vertical cross-sectional view through the folding device with swivel levers, stationary rollers, a part of the rocker arm of the sleeve shown broken away, and a top view of the pusher, in a first position shortly after insertion of the sleeve, which has only partially opened,

Figure 2

a representation similar to Figure 1, but with the sleeve already shown in its fully unfolded state,

Figure 3

2 shows a longitudinal section through the folding device, for example through the vertical center line of FIG. 2 with the drive for the swivel levers,

Figure 4

2 shows a view similar to FIG. 1, but showing another embodiment with pivot levers without stationary rollers,

Figure 5

3 shows a view corresponding to FIG. 3, but in the embodiment of FIG. 4 without the stationary rollers,

Figure 6

a view of the distributor rocker in the direction of its pivot axis,

Figure 7

6 shows a view of the distributor rocker along the line VII-VII in FIG. 6,

Figure 8

3 shows a plan view of the arched basket, which is only broken off in FIG. 6 and is indicated at the bottom right,

Figure 9

8 shows a plan view of the basket of FIG. 8,

Figure 10

a side view of the pusher with broken drive lever,

Figure 11

a plan view of the end face of the square plate with the raised ring made of rubber,

Figure 12

a plan view of the guide, which is shown in Figures 3 and 5 left in the side view, and

Figure 13

a cross-sectional view through the frame of the folding device without a slide and without a pivot lever.

In the embodiment described in the following it is assumed that the rocker 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. 13, which is connected in a stationary manner to the floor below by means of the screws, which are not described in any more detail, but are shown. To simplify the drawings, only the right-hand work station seen in the push-on direction of the sleeves 2 is shown, the person skilled in the art but a left station must also think of itself 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 slider 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 these in the axial direction of the mandrel 9 (shown at the top right in FIG. 8) of the push-over element 7.

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 '(Figure 8) also runs parallel to the axis of rotation 12 of the pivoting lever 13 and also the linear direction of movement of the pusher 7 running along the axis 22, namely in the direction of the rails 6. In this 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 middle part of the folding space is shown under the folding stop 10 with the contact plane 14 and the rollers 16, in the right third in frame 5 the push-button 7 is indicated and on the opposite side of the folding space the one generally designated 23 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 pusher 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 pusher 7 connected.

With reference to FIG. 10, it can be seen that the steel housing 30 has the shape of a cup with cylinder-wall-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 push-button 7 being 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 Figure 7 right and left or in Figure 6 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 jaws 56 are attached to both straight end edges 55 of the holding plate 51 and are provided with receiving surfaces 57 which are V-shaped in cross-section and project outwards (right and left). The centering jaws 56 have the length of the straight end edge 55 and thus also a strip 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 jaw 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 next to one another by the pivot levers 13 are kept sucked.

Now the unfolding process is initiated, because with further curved movement of the distributor rocker 20 and thus its centering jaw 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 jaw 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 pusher 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 engages with and is held by the square 35 of the pusher 7, as shown on the left in FIG.

3, the front edge opposite the rear edge 40 of the sleeve 2 is 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 jaw 56, which is why this occurs when the Distributor arm 20 is moved clockwise in the other direction.

The pusher 7 has meanwhile already pushed the sleeve 2 onto the mandrel 9, and now the rubber ring 38 of the pusher 7 engages 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 pusher 7 has now carried out its forward stroke, which is longer than the length L of the pivot lever 13 in Figure 3.

In the meantime, the distributor rocker 20 with the left centering jaw 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 not shown pusher 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 pivoting levers are also controlled synchronously via not shown Drive devices 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. Apparatus for opening up casings (2), which are in a condition of lying flat, of paper, cardboard or the like having a longitudinal sealing seam (4), in particular for the production of liquid packs, comprising a transportation device (8) for gripping the casings (2) which are lying flat and introducing the into a sliding guide means (10, 13, 14) axially in alignment between a mandrel (9, 9') and a push-over means (7), wherein the transportation device (8) has a rocker member (20) pivotable about an axis (53) which is disposed parallel to the linear direction of movement (22) of the push-over means (7), the sliding guide means (10, 13, 14) has a stationarily fixed fold abutment (10) with receiving surfaces (11) which are arranged in a V-shape, and the push-over means (7) which is provided at its front end with a plate (35) has a stroke movement which is greater than the length (L) of the sliding guide means (10, 13, 14) and is reciprocatable controlledly synchronously with respect to the pivotal movement of the rocker member (20), characterised in that the rocker member is provided at its end which grips the casing (2) with a centering jaw (56) and is pivotable along a stationary guide means (60) in the form of part of a cylindrical surface, that the limit position of the centering jaw in which it is swung out is disposed in opposite relationship to the fold abutment (10), beside which and on both sides pivotal levers (13) with vacuum openings (24) are provided pivotably in such a way that two contact planes (14) each delimiting a respective pivotal lever (13) define a V-shaped roof corresponding to two juxtaposed side surfaces (71, 72) of the casing (2) which is opened up, and that the plate of the push-over means (7), which is in the form of a quadrangular plate (35), is movable along the contact planes (14) which are disposed in a V-shape.
2. Apparatus according to claim 1 characterised in that the rocker member (20) has an arm (50) and at the radially outward end thereof a holding plate (51) which is in the form of a part-cylindrical surface, that the centering jaw (56) is fixed to at least one straight end edge of the holding plate (51), the centering jaw having receiving surfaces (57) which open outwardly in a V-shape in cross-section, and that the sliding guide means (60) which is in the form of a part-cylindrical surface is in the form of a cage and is disposed stationarily beside the path of movement of the holding plate (51) (Figures 6 to 8).
3. Apparatus according to claim 1 or claim 2 characterised in that the stationary fold abutment (10) is in the form of a bar which is longer than the casing (2) to be opened and is approximately as long as the pivotal lever (13) in the axial direction (12).
4. Apparatus according to one of claims 1 to 3 characterised in that the contact plane (14) of the pivotal lever (13) has recesses (15) in which stationarily arranged rollers (16) are accommodated (Figure 3).
5. Apparatus according to one of claims 1 to 4 characterised in that a guide means (23) defining a quadrangle corresponding to the cross-section of the casing (2) is stationarily disposed on the side of the fold abutment (10), which is towards the mandrel (9, 9') of the machine (Figures 1 and 12).
6. Apparatus according to one of claims 1 to 5 characterised in that the push-over means (7) has a cup-shaped housing (30) in which the quadrangular plate (35) is resiliently biased relative to the cup bottom (36) and is arranged at a spacing (d) from same and linearly movably, and that the edge (39) of the quadrangular plate (35), which edge corresponds to the peripheral contour of the opened casing (2), extends inclinedly inwardly.
7. Apparatus according to one of claims 1 to 6 characterised in that a raised ring (38) of elastomeric material is let into the front face (37) of the quadrangular plate (35).
8. Apparatus according to one of claims 1 to 7 characterised in that the rocker member (20) is in the form of a distributor rocker member and has two oppositely disposed centering jaws (56) and is arranged pivotably almost in a semicircular configuration approximately centrally between two fold abutments (10) with pivotal levers (13), wherein the cage-like sliding guide means (60) is preferably in the form of a semicylindrical surface.

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