EP0111446B1 - Method for packing tubular bags in boxes, and device for carrying out the method - Google Patents

Abstract

The present invention is directed to a method and apparatus for packing tubular bags into boxes by machinery. The tubular bags to be packed are conveyed over various conveyor belts to a positioning belt and from the positioning belt to a positioning table. Layers of tubular bags are then moved onto a rake-like main base that is lowered in a stepwise fashion to receive consecutive layers of tubular bags. When the desired number of tubular bag layers is positioned on the main base, the main base is lowered to deposit the tubular bags onto an intermediate base which together with side walls makes up an intermediate container. Once the intermediate container is in a lower position, a box is pushed over the intermediate container and the intermediate container is swung through a 90 DEG arc onto a conveyor belt. The intermediate container is then removed from the box and by this process the tubular bags which were previously in the intermediate container are transferred into the box. The intermediate container then swings back to its lower position.

Description

The present invention relates to a method for packaging tubular bags in boxes, and to a device for performing the method according to the invention.

Tubular bags are packaging made from an endless, welded flexible tube. Such bags can have different cross-sectional shapes depending on the content. The tube is closed at the bottom in a first cycle, filled with the material to be packaged in a second cycle and finally sealed and separated from the tube in a further cycle. Such packaging is particularly suitable for packaging liquid and pasty substances.

Both the soft packaging, the tubular bag and its flowable content result in a non-dimensionally stable unit that is extremely difficult to machine. It is therefore not surprising that previously the filled tubular bags could only be packed by hand.

Devices for the mechanical packaging of such bags filled with a liquid or paste have hitherto not been disclosed.

US Pat. No. 3,748,797 (yours) describes a device for packaging bags which are filled with french fries. These are first shaken in the device so that the content is oriented somewhat flat. This would be inadmissible for sensitive bags filled with liquid. Then the bags are individually pushed onto trays which are arranged one above the other on levels. If there is a bag on each of the trays, the trays are brought closer to one another, the bags being pressed together. The bags combined in this way are then pushed from the side of the trays by pushers and pushed into a box.

U.S. Patent No. 3,745,740 (Williams) describes a method and apparatus for packaging Berliner pancakes. The pancakes fall from a conveyor belt into a tube on a slowly descending tray so that the fall height remains about the same. When the tube is filled, the tray lowers further until the stack of pancakes is exposed so that it can be pushed into a box by a pusher.

CH-PS-337 442 (Sapal) relates to a device for packaging rectangular, relatively rigid bags in boxes. Such a device can naturally be of relatively simple construction.

However, it is an object of the present invention to provide a method for mechanically packaging sensitive tubular bags with liquid or pasty content and to provide an apparatus for carrying out the method.

The tubular bags should be stacked in several layers, with a large number of bags in each layer.

• a) die Schlauchbeutel schichtweise,, zwischen zwei seitlichen und einer, die Tiefe begrenzenden Wand, auf einen schrittweise absenkbaren, rechenartigen Hauptboden gefördert werden ;
• b) sobald die gewünschte Zahl Schichten von Schlauchbeuteln erreicht ist, der Hauptboden abgesenkt wird und die Schlauchbeutel auf einen ebenfalls rechenartigen Zwischenboden mit Seitenwänden, die in der oberen Ausgangslage aussen an den stationären Seitenwänden anliegen, abgelegt werden ;
• c) sobald der Zwischenboden in eine untere Endlage abgesenkt worden ist, wobei sich der Hauptboden in einer tieferen Endlage als der Zwischenboden befindet, eine Schachtel über das Sammelbehältnis aus Zwischenboden mit Seitenwänden geschoben wird, die Schlauchbeutel hierin abgelegt werden und die Schachtel mit den abgepackten Schlauchbeuteln abtransportiert wird.

The method according to the invention is characterized in that

• a) the tubular bags are conveyed in layers, between two side walls and a wall that limits the depth, onto a step-by-step lowerable, rake-like main floor;
• b) as soon as the desired number of layers of tubular bags has been reached, the main base is lowered and the tubular bags are placed on a likewise rake-like intermediate base with side walls which in the upper starting position lie against the outside of the stationary side walls;
• c) as soon as the intermediate floor has been lowered into a lower end position, the main floor being in a lower end position than the intermediate floor, a box is pushed over the collecting container from the intermediate floor with side walls, the tubular bags are placed therein and the box with the packaged tubular bags is transported away.

Suitable for carrying out the above-mentioned method is a device which is characterized in that at least two height-adjustable, rake-like floors, namely the main and intermediate floors, are guided between two columns in which means for height adjustment are arranged, and that in the upper area the columns two fixed, side walls and an end wall together with the height-adjustable main floor form an intermediate container, which is partially surrounded by the collecting container, formed from the intermediate floor and two attached side walls, which are somewhat further apart, such as the aforementioned fixed side walls, so that when the main floor is lowered below the level of the intermediate floor, the contents of the intermediate containers are placed in the collecting container, over which a box can be pushed.

The method according to the invention and a device operating according to the method are explained below with reference to the accompanying drawings.

• Figur 1 die Zufuhreinheit für die abzupackenden Schlauchbeutel der erfindungsgemässen Vorrichtung im Aufriss, und
• Figur 2 dieselbe Einheit im Grundriss, in der weitere Teile der Vorrichtung ersichtlich sind, in
• Figur 3 ist die Sammel- und vertikale Transport-Einheit im Aufriss und in
• Figur 4 im Seitenriss dargestellt.
• Figur 5 . dient insbesondere zur Veranschaulichung der Uebergabe der abzupackenden Schlauchbeutel vom Sammelbehältnis in die Schachtel.

The drawing shows:

• Figure 1 shows the feed unit for the tubular bag to be packed of the device according to the invention in elevation, and
• Figure 2 shows the same unit in plan, in which further parts of the device can be seen in
• Figure 3 is the collection and vertical transport unit in elevation and in
• Figure 4 shown in side view.
• Figure 5. serves in particular to illustrate the transfer of the tubular bags to be packaged from the collecting container into the box.

All of the figures represent highly simplified schematic diagrams, leaving out all the details that are obvious to a person skilled in the art. To simplify matters, different units are shown separately, which together only give the device according to the invention.

The description speaks uniformly of “pneumatic cylinder / piston units”, but these can of course also be hydraulic, although equivalent electromechanical means should not be excluded.

The tubular bags 1 to be packed are initially conveyed up from a lower level to a higher level by a conveyor belt 2 (FIG. 2) arranged in a ramp-like manner. Here the tubular bags reach a horizontal conveyor belt 3 controlled by light barriers. The light barriers, not shown, determine when a tubular bag lies in front of the sliding plate 4 and immediately stop the conveyor belt 3. A slightly time-shifted signal controls a pneumatic cylinder / piston unit 5, which moves the plate 4 running parallel to the conveyor belt 3 transversely to its direction of travel over the belt 3. The tubular bag located in front of the plate 4 is thus pushed off the conveyor belt 3 and slips over a ramp 6 onto the positioning belt 8 underneath. A stop 7 prevents the tubular bags 1 from sloping or sliding too far forward onto the positioning belt 8. The positioning belt 8 is profiled accordingly in order to guarantee an exact positioning of the tubular bags on it.

In the present example, the positioning belt is formed from a chain of plastic rollers 9, the length of which corresponds at least to the length of the tubular bag to be packed. The recess between two adjacent rollers 9 exactly define the position of the tubular bag 1. As soon as a tubular bag has fallen onto the positioning belt 8, it is moved by the distance between the axes of two adjacent rollers 9. A comb-like rake 10 is attached approximately in the middle of the belt 8 parallel to its plane and direction of travel. The tooth shape of the rake 10 corresponds to the profile of the positioning belt 8. If the foremost tubular bag 1 in the direction of movement of the positioning belt 8 is in front of the last tooth of the rake 10, which in turn can be scanned opto-electrically, the belt stops. Now a pneumatic piston / cylinder unit 11 of the rake 10 is moved transversely to the conveying direction of the positioning belt 8 and all tubular bags lying in front of the rake are pushed onto a positioning table 12 by the positioning belt 8.

The positioning table 12 is approximately at the level at which the tubular bags 1 lie on the positioning belt 8, or just above it. Two pneumatic actuatable slides 13 located on both sides of the positioning table 12, after the table has been pushed up to beyond the loading surface of the main floor 23, collide the tubular bags lying on the table. The tubular bags lying on the positioning table 12 remain in this position until a pivoting plate 14 which is articulated above the positioning table 12 holds back the pushed-together tubular bags and the table is pulled back into its starting position. As a result, the tubular bag layer reaches a height-adjustable main or auxiliary floor or an already existing tubular bag layer. The tubular bags were pushed slightly closer together by the slides 13 than the distance between the fixed side walls, which will be described below. Then both the slider 13 and the swivel plate 14 return to their starting position.

With the delivery of the tubular bags from the positioning table 12 to the main floor, the tubular bags are located in the vertically movable collecting transport unit shown in FIGS. 3 and 4. The height of the entire unit is shown shortened for reasons of space. The unit comprises two vertical columns 20 in which there are two closed chains 21, 22 arranged one behind the other for height adjustment. The outer pair of chains is driven, for example, by an electric motor M ″, the inner pair of chains 22 by an electric motor M _2. A pair of chains, for example the inner 22, serves to adjust the height of the main floor 23 already mentioned. The main floor, which opens up between the two columns 20 is movable downwards, is in a first phase approximately at the level of the positioning table 12. After a first layer of tubular bag 1 is pushed from the positioning table onto the main floor 23, it is moved by the motor M ₂ by means of its chain pair 22 by the height of a layer of tubular bag The exact position of the tubular bags is defined laterally by two side walls 24 which are fixedly mounted in the unit 24. The tubular bags are defined in the insertion depth by the rear wall 25. This wall 25 consists of several flat bars lying in one plane round bars, which together form a rake-like grate, slides up and down between the fixed walls 24 as described above. The bars of the main floor 23 reach into this area between the flat bars of the rear wall 25.

As soon as a layer of tubular bags lies on the main base 23, a pneumatically driven plunger 26, which corresponds approximately to the size of the main base 23, lowers and presses on the tubular bags. Now the main floor is lowered by the height of a layer of tubular bags. This cycle is repeated until the desired number of layers are on the main floor 23. As soon as this number is reached, the Motor M ₂ controlled and the main floor 23 lowers further.

The main base 23 and the fixed side walls 24 and the rear wall 25 together form an intermediate container. This intermediate container is surrounded by a collecting container, which consists of a rake-like intermediate base 27 with two side walls 28 and a rear wall 29, which in turn is formed from flat bars. The bars of the rake-like intermediate floor 27 are arranged offset with respect to the bars of the main floor 23. When the main floor 23 is lowered, its bars slide between the bars of the intermediate floor so that the content of the intermediate tank comes to rest on the intermediate floor 27 of the collecting tank. The intermediate floor is also adjustable in height by means of a pneumatic piston / cylinder unit 30.

So that the machine works fast enough on the one hand, but on the other hand the content of the intermediate container is not lowered too abruptly onto the intermediate floor, both the main and intermediate floor slide down at the same time, but the main floor at a higher speed. The intermediate floor 27 slides into a lower basic position 27 ', while the main floor 23 leading it moves into a lower lower basic positions 23'.

While the main floor 23 is in the lower basic position 23 ', an auxiliary floor 31 takes over its task. The auxiliary floor 31 is pushed hydraulically from its horizontal retracted position forward into a carriage 32 into the area between the fixed side walls 24. The entire carriage 32 with the auxiliary floor is suspended from the outer chains 21 and can be moved in height above the motor M ₁ . The other mode of operation corresponds completely to that of the main floor, until the time that the main floor 23 comes up again, takes over the content already in the intermediate container and the auxiliary floor can retract back into its original length. The auxiliary floor thus ensures continuous operation.

The last step of the packaging process is shown with reference to FIG. 5, in which the transfer unit is illustrated. Briefly recapitulated you can see on the figure the tubular bag conveyor section 2, 3, 4, and the vertical transport unit illustrated by the columns 20. The collecting container 27, 28 is shown in its lower position. The machine frame is generally designated 33. The feed unit 34 for the boxes 40 is only partially recognizable. A box 40 is shown lying on a platform 35. The platform 35 is mounted together with a piston / cylinder unit 36 so as to be pivotable about an axis 37 mounted in the frame 33. The pivoting movement of the platform 35 takes place via a pneumatic piston / cylinder unit 38 which engages an angled arm 39. By acting on the unit 38, the platform is first pivoted about the axis 37 by 90 °. After this pivoting, the box lying with its opening upward on the platform 35 lies on the side with the opening towards the collecting container. The lower edge of the box is located slightly lower than the level of the intermediate floor 27 '. The box 40 is then pushed over the collecting container by means of the pneumatic unit 36.

The pneumatic piston / cylinder unit 30, which controls the vertical movement of the intermediate container, is supported between two fork-shaped arms 41 which are connected to one another. The two arms 41 are in turn rotatably supported about the axis 37 and can be pivoted about that axis 37 by means of a pneumatic piston / cylinder unit 42 which engages the arms 41.

If the box 40 has been pushed over the collecting container, the piston / cylinder unit 42 is actuated and the arms 41 begin a rotary movement by 90 °. At the same time, in addition to the arms 41, the collecting container 27, 28 with the contents of stacked tubular bags as well as the box and the extended platform 35 swivel including content, too. The now pressureless piston / cylinder unit 36 is thus pushed in and the box 40 gently lowers back into the starting position on the conveying path of the feed unit 34.

As soon as the collecting container is pivoted out of the area between the columns 20, the main base 23 is moved up again, takes over the tubular bags already stacked on the auxiliary base 31 and the auxiliary base is pulled back into the slide 32 and raised to its starting position.

Finally, the empty intermediate container is swung back and raised to the upper position. Now the whole process cycle can start again.

If no continuous operation is required, the device can also be designed without an auxiliary floor 31.

Claims (10)

1. A method of packaging tubular bags in boxes, characterised in that

a) the tubular bags (1) are conveyed in layers between two lateral walls (24) and one wall (25) which defines the depth on to a rack-like main tray (23) which is lowerable in step-wise manner ;

b) as soon as the desired number of layers of tubular bags (1) is reached, the main tray (23) is lowered and the tubular bags are placed on to an intermediate tray (27) which is also rack-like with lateral walls (28) which rest externally on the stationary lateral walls (24) in the upper starting position ;

c) and as soon as the intermediate tray (27) has been lowered into a lower end position (27'), the main tray (23) being located in a lower end position (23') than the intermediate tray (27), a box (40) is pushed over the collecting case composed of intermediate tray (27) with lateral walls (28), the tubular bags are deposited herein and the box (40) with the packaged tubular bags is conveyed off.

2. A method according to claim 1, characterised in that the box to be filled is supplied with the open side uppermost, is then pivoted about 90°, the lower lateral wall lying just below the plane of the intermediate tray, is subsequently pushed over the collecting case comprising intermediate tray (27) and lateral wall (28) and is pivoted back into the starting position with the collecting case.

3. A method according to claim 1, characterised in that as soon as the main tray (23) and the intermediate tray (27) have left the loading position, a rack-like auxiliary tray ₍₃1 ) is pushed in horizontally, the auxiliary tray assuming the function of the main tray (23) and being lowered in layers until the desired number of layers or until the main tray (23) can assume its function again and the auxiliary tray (31) can travel back into its starting position.

4. A method according to claim 1, characterised in that the tubular bags are pushed from a conveyor belt (3) on to a cyclically moving positioning belt (8) and, from here, after reaching the number of tubular bags (1) required for a layer are pushed by a rack (10) from the positioning belt (8) on to a positioning table (2) and are pushed together laterally here, whereupon the table is advanced, a retaining pivoting plate (14) ensuring that a layer passes on to the main tray or auxiliary tray (23, 31) or on the uppermost layer of tubular bags already lying thereon respectively during retraction of the positioning table (12).

5. A method according to claim 1, characterised in that after each new layer of tubular bags, which has been pushed on to the main or auxiliary tray (23, 31), the tubular bags are compressed from above by means of a ram (26).

6. An apparatus for carrying out the method according to claim 1, characterised in that at least two vertically adjustable rack-like trays, namely the main tray (23) and the intermediate tray (27) are guided between two columns (20) in which means (21, 22) for vertical adjustment are arranged, and in that in the upper region of the columns (20) two stationary lateral walls (24) and one rear wall (25) together with the vertically adjustable main tray (23) form an intermediate case which is partially surrounded by the collecting case formed by the intermediate tray (27) and two lateral walls (28) fixed thereon which lie somewhat further apart than the above-mentioned stationary lateral walls (24), so that when the main tray (23) is lowered below the level of the intermediate tray (27) the content of the intermediate cases is deposited into the collecting case over which a box (40) can be pushed.

7. An apparatus according to claim 6 for carrying out the method according to claim 2, characterised in that the apparatus has a supply line (34) for the boxes (40) in which a platform (35) is pneumatically pivotal and movable, by means of which a box which is pushed on the platform (35) and serves for packaging tubular bags (1) is pivoted about 90° and can be pushed over the collecting case and in that the collecting case is fixed with its vertical adjustment means (30) on two arms (41), which arms (41) are pivotal about an axis (37) lying parallel to the connecting plane of the two columns (20) as close as possible to the supply line (34).

8. An apparatus according to claim 6 for carrying out the method according to claim 3, characterised in that an auxiliary tray (31) which is horizontally movable via a cylinder-piston unit and temporarily assumes the function of the main tray (23) is provided between the two columns (20) on vertical adjustment means (21, 22) arranged in them.

9. An apparatus according to claim 6 for carrying out the method according to claim 4, characterised in that the apparatus has an opto-electrically scanned conveyor belt (3) for supplying the tubular bags (1) to be packaged from which the tubular bags (1) are pushed by a piston-cylinder unit (5) on to a positioning belt (8) which is controlled in step-wise manner and thence can be pushed by a comb-like rack (10) on to a positioning table (12) running in the plane of the positioning belt (8), in that two lateral sliders (13) push the tubular bags to be packaged together on the positioning table (12), in that the positioning table (12) has means for pushing forwards and backwards, and in that a pivoting plate (14) holds back the layer of tubular bags when the table is advanced so that the tubular bags passon to the auxiliary tray (23) or main tray (31) when the table (12) is retracted.

10. An apparatus according to claim 6 for carrying out the method according to claim 5, characterised in that a vertically movable ram (26), by means of which each layer of the tubular bags to be packaged can be compressed, is arranged between the two columns (20) above the highest position of the main tray (23) or auxiliary tray (31).

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