EP0085399B1 - Method and apparatus for automatically introducing square-shaped bags - Google Patents

Description

The invention relates to methods and devices for automatically inserting box-shaped sacks made of flexible packaging material into box-shaped large containers, according to the preamble of claims 1 and 4 (known from US-A-4 083 293).

It is known to pour bulk goods into box-shaped containers e.g. pack out of cardboard or metal. To protect the packaged goods, e.g. in the case of cardboard packaging, a protective wrapping with a plastic material is also carried out. This additional wrapping made of flexible packaging material is generally carried out on the outside of the box-shaped containers and only in special cases by inserting bags made of flexible packaging material, which have either a round or a square cross-section. Such forms of packaging are used in particular when the goods to be packaged must not come into contact with the shaping material of the packaging container used. For the insertion of such bags into small containers, which are suitable for packaging from gram to kilogram quantities, a number of automatic packaging machines have been designed which allow a large number of such packaging containers with inserted bags to be produced automatically from flexible packaging material. Such devices are very expensive due to their high throughput per unit time.

Examples of such packaging machines which enable the automatic insertion of bags into containers are described in US-A-41 42 453 and US-A-40 83 293. The plastic bags intended as inlays are inserted into the containers with the aid of rigid molded bodies or can be clamped in the direction of 2 opposite sides, and at the same time the edges of the bags are placed over the container walls in order to ensure perfect reception e.g. allow perishable foods.

The use of such packaging machines for inserting large box-shaped sacks made of flexible packaging material into box-shaped large containers is practically not possible since, for example, damage to the box sacks must be expected under these conditions. Large box-shaped containers are understood to mean those which have a packaging volume of more than 100, preferably more than 200 l. A preferred area of use for such box-shaped large containers is e.g. given in the filing and pressing of thread cables, as described in DE-OS 27 36 316. In the method according to the aforementioned literature, it is necessary to use box-shaped bags made of flexible packaging material in metallic support containers of the same size. Thread cables can be stored and pre-pressed in the support containers equipped in this way. After the filled support container has been transported to a final press, the support container is pulled off and the cable material pre-pressed in the box-shaped bag is then subjected to a final compression in the form of a bale. Large containers are also suitable for packaging cable tapes and fiber flakes, which must be lined with box-shaped bags made of flexible packaging material to protect the packed material against contamination on the container walls.

An automatic insertion device and a suitable automatic method have not been proposed for such fields of application. The assembled box-shaped sacks are usually inserted into these large containers by hand and, if necessary, spread out in the containers using the simplest mechanical aids. However, such methods are very labor-intensive and hinder known packaging processes which usually take place continuously. For example, when using a device for pressing and packing thread cables, it is necessary to line the support containers with box-shaped sacks in the late and night shifts in uninterrupted continuous operation.

It was already known from US-A-34 31 704 to provide folded bags on a magazine track for collecting waste from a garbage chute. Here, the sacks, which have a folding mechanism that can be snapped open and closed at their upper open edge, are connected to each other with the aid of 2 clamps of the telescopic frames and simultaneously guided in the magazine path. The snap mechanism can be triggered for the filling of the sack by appropriate tensile forces, i.e. be opened. A disadvantage of this system is the complex fastening of the bags in the folding mechanism. Inserting box-shaped bags into appropriate containers is not described.

There was therefore still a need to find a method and a suitable device which would allow large box-shaped sacks made of flexible packaging material to be inserted into large box-shaped containers, the individual work steps no longer being able to be carried out manually, but one after the other, fully automatically.

An operationally reliable solution to the described task has now been found. According to the invention, it is necessary to carry out a specific packaging process using novel devices. They are the subject of claims 1 and 4, while particularly preferred embodiments were set out in the subclaims.

To explain the invention, the method will first be described with reference to FIGS. 1 to 12, while special features of the device according to the invention are only to be described thereafter.

The method according to the invention is aimed at automatically inserting box-shaped sacks made of flexible packaging material into box-shaped large containers. Corresponding clothing sets made of foils, jute fabrics or the like can be used as flexible packaging material. For many purposes, the use of plastic film, which is laminated with a plastic film ribbon fabric, has proven itself, since such a material can be easily cut and sewn into box bags, glued or welded, but on the other hand has a much better tear resistance than usual Foils.

Prefabricated box bags (1) must first be entered into the device. Trolleys (2), which are provided with at least four clamping points (3, 3 ', 4, 4'), are used for this purpose. These clamping points must be so far apart in pairs that two opposite side surfaces of a sack can be clamped in at the upper edge, while the other two side surfaces and the bottom of the sack remain folded together. FIG. 1 shows such trolleys (2) equipped with box bags (1). The trolleys (2) are stored on a first magazine track (5) and brought up to a stop (6) with the help of a pushing device (not shown). A pulling device (7) is then extended from the opposite side of the stop (6) and is equipped with at least two grippers (8, 8 ') which are approximately as far apart from one another as a side surface of the sack is wide. The grippers (8, 8 ') can be actuated e.g. via a small servo motor with lever system or via a pneumatic drive (not shown). The grippers (8, 8 ') can be raised above the edge of the closest side surface of the box sack (1) and then lowered to the edge of the sack, this side surface being clamped resiliently into the grippers (8, 8'). The pulling device (7) is then moved back with the grippers (8, 8 '). The clamping connection of the clamping points (4, 4 ') of this side of the bag (1) is pulled out of the trolley (2) and the bag is shown as shown in FIGS. 1 to 3, at least spread out at its upper end.

A spreading device (9), the spreading elements (10, 10 ') of which are folded in, is then inserted into the open sack and then the spreading elements (10, 10') are extended, the sack being stretched. FIG. 4 shows this insertion of the expanding device (9) in the folded state. The spreading elements are expediently designed as a fourfold lever frame system which can be moved, for example, by a pneumatic drive system (11). The spreading elements (10) are aligned along the four longitudinal edges of the box bag. By extending the spreading device (9), the sack is completely spread out and stretched between the spreading elements (10, 10 '), so that it is no longer possible for the sack to fall off, at least when the spreading device (9) is in a stretched state.

The sack edge is released from the clamping points (3, 3 ') on the trolley (2) and from the resilient grippers (8, 8') of the pulling device (7) by simply lowering the spreading device (9) further beyond the transfer point.

On the individual spreading elements (10) of the spreading device (9) there are clamps (12) which can be actuated in the vicinity of the edges of the bag and which are actuated by the spreading device at the latest after the stretched bag has been finally taken over. The actuatable clamps (12) are arranged at such a height that they can hold the sack (1) stretched out on the expansion device (9) after tensioning and smoothing at its upper edge. After actuation of the clamps (12), the spreading device (9) can be retracted or folded up. The tensioned state of the sack after it has been removed from the clamping points (3,3 ') and the resilient grippers (8, 8') of the pulling device (7) is shown in Fig. 5, while in Fig. 6 the state of the sack and the spreader are shown in Fig. 6 Folding in of the expansion device (9) can be seen. In this state, the spreading device can be moved into a box-shaped large container (14) with the aid of a movement device (13) and lowered there.

In Figure 6 the trolley (2) and the pulling device (7) with the grippers (8, 8 ') can no longer be seen. The trolley has been lifted onto a second magazine path (16) with the aid of a lifting device (15), on which the trolley (2) can be guided back onto the first magazine path (5). The details of the arrangement of the lifting device (15) and the second magazine track (16) will be discussed later in connection with the device; they are shown in Figure 11.

The pulling device (7) has been removed from the effective range of the expansion frame (9) and thus from the vicinity of the open jaw (1) by moving back with the aid of a movement device, not shown.

After lowering the spreading device (9) fitted with the box bag (1) into the the large container (14) which is to be fitted, the expansion device (9) is slowly extended, the box sack being applied to the entire surface of the container walls. The position of the box bag (1) in the large container (14) can be fixed in various ways. For example, the inner wall of the large container (14) can have absorbent or adhesive points which allow the position of the sack to be fixed in the large container (14). Preferred embodiments of fixing the position of the box bag (1) in the large container will be described below. If the position of the sack is ensured by one of these measures, the clamps (12) can be released, the spreading device (9) folded in and the entire spreading device can be moved out of the large container (14). The large container is then equipped on its inner surfaces with the box bag (1) of the appropriate size.

FIGS. 7 to 12 show preferred embodiments of the method according to the invention and the device required therefor.

In these preferred process variants, the upper edge of the box sack is cut into a length (a) and the foldable strips that are formed on the upper edge of the box sack (1) are connected to holding devices (17) on the upper edge of the large container. For this it is necessary that the box sack (1) is held at the upper ends of the longitudinal edges by two clamps (12 ', 12 "), which are located near the sack edge. A corresponding schematic representation in a top view is shown in FIG 12. Between the two brackets (12 ', 12 ") of each edge of the box sack, an actuatable knife (18) acts, which can be swung in and out by a movement device, not shown. By swiveling out the knives in the edge of the box bag (1), the edges of the box bag are cut open over a predetermined length (a) (FIG. 7).

After the upper edges of the box bag (1) have been cut open by the knives (18), the expansion device (9) is usually folded in, the box bag (1) is then sunk into a large container with the help of the expansion device (9) and the expansion device (9 ) clamped in the container (14). After loosening the clamps (12) or (12 ', 12 "), foldable edges of the box sack (1) are now available, which can be connected to the upper edge of the large container (14) Fixing the position of the box bag in the large container (14) results, for example, by gluing, acting by suction heads, attaching or clamping.

The operation of the knives (18) is shown schematically in FIG. 7, while FIG. 8 shows a preferred form of fixing the position of the box bag 1 in the large container (14). The upper edges of the sack (1), which have become freely movable as a result of the action of the knives (18), are pushed into the resilient holding devices (17) of the large container (14) with the aid of a transfer device (19). According to FIG. 8, the transfer device (19) consists of a pneumatic drive (20) whose piston rod sets lever systems (21) in motion, which change the position of sword-like plates (22). In FIG. 8 only two of the four lever systems and transfer swords (22) are shown. The transfer takes place in such a way that when the pneumatic drive (20) is extended, the sword-like transfer devices (22) act on the upper edge of the bag (1). After loosening the clips (12) or (12 ', 12 "), it is possible to push the upper edge of the box bag (1), which has been cut into the edges, under the holding devices (17) of the large container (14). In FIG. 9 the transfer of the box sack to the holding device (17) is carried out, the spreading device is retracted and is removed from the inside of the large container with the aid of the movement device (13) .The large container is now ready for packaging, for example according to the method of DE-OS 27 36 316 can be used for storing thread cables.

Figure 10 shows a cross section along the line X..X of Figure 8. From this figure it can be seen that the expansion frame (10) fit into the edges of the box bag and the large container. It is thus possible to insert the box bag (1) into the large container (14) largely without wrinkles.

An embodiment of the device required according to the invention is shown schematically in FIG. The box bags (1) used are inserted into the brackets (3, 3 ', 4, 4') of the trolley (2). These trolleys (2) are guided on a first magazine track (5). The brackets (3, 3 ') and (4,4') are each so far apart that at least one side of the box bag (1) can be clamped spread out between them. The clamping points (3 and 3 ') consist of a fixed part (23, 23') which is rigidly connected to the linkage of the trolley (2) and a resilient part (24, 24 ') that allows the clamping of packaging material . The clamping points (4,4 ') are designed in a similar way. In contrast to the fixed parts (23, 23 '), the fixed parts (25, 25') are, however, movable about the pivot points (38, 38,), the resilient parts (26, 26 ') correspond to the springs (24, 24') .

The trolleys (2) must be able to be easily moved back and forth on the magazine track (5), for example by means of rollers or sliders or the like. The shape of the magazine track can be that of an open one Railroad. The use of so-called C-rails for guiding the rollers of the carriage (2) has proven itself, for example.

The trolleys (2) are moved using a pushing device (27) which has a reciprocating drive (28). The trolleys (2) are moved on the first magazine track (5) by actuating the drive (28) to which a ratchet (29) is connected, which can interact with the trolleys (2). By actuating the pushing device (27), the trolleys (2) are transported on the magazine track (5) until the first carriage reaches the stop (6) of the first magazine track (5).

After the sack (1) has been handed over to the spreading device (9), the now empty trolley (2) must be lifted onto a second magazine track (16). This can be done, for example, by a lifting device (15) which can raise the end piece (30) of the magazine track (5) including the stop (6) up to the height of the second magazine track (16). A pneumatic drive (31) in turn serves to drive the lifting device (15). The empty trolley (2) then continues on the inclined magazine path (16) up to an actuatable stop (32) if there are no further empty trolleys (2) on the magazine path (16). The connection between the first magazine path (5) and the second magazine path (16) is established by a movable path part (33) which can be pivoted about the axis (34) with the aid of a movement device (35). The empty trolleys can continue to roll up to a stop (36) with the part (33) raised and the stop (32) open. After closing the stop (32), the web part (33) can then be lowered to the height of the first magazine web (5) and the trolleys (2) can be transferred from the movable web part (33) to the first magazine web (5).

The pulling device (7) is indicated opposite the stop (6) and can be advanced with its gripper arms (8, 8 ') with the aid of a device (not shown) up to the vicinity of the stop (6). The grippers (8, 8 ') are actuated via an actuator (37). When the piston of the actuator (37) extends, the gripper arms (8, 8 ') swivel upwards and can thus be lifted over the first edge of the sack, which is located in the trolley, which is at the stop (6). After lowering the gripper device (8, 8 '), the edge of the bag is held resiliently by the grippers.

When the traction device (7) moves back with closed grippers (8, 8 '), the gripped sack can be pulled out of the clamping points (4, 4') of the trolley without the clamping in the grippers (8, 8 ') changing . The clamping points (4, 4 ') pivot about their axes (38, 38'). The grippers (8, 8 ') are also intended to hold a side of the clamped sack (1) in a spread out position, so it is necessary for the grippers (8, 8') to be almost as far apart as one side of the box sack is wide.

In order to be able to transfer the sack that is spread out between the clamping points (3, 3 ') and the grippers (8, 8') into a large container (14), it is necessary to transfer the sack out to a spreading device (9). This spreading device (9) preferably consists of four spreading elements (10, 10 '), which can be moved via a drive system (11). The spreading device (9) is fastened to a movement device (13) which allows the spreading device (9) to be moved at least in the vertical direction, but possibly also in the horizontal direction. The spreading elements (10) are movably attached to the movement device (13) via axle bolts (39) and are movably connected on their lower side to spreading elements (10 ') which are movably connected to the piston of the drive (11). The position of the expansion elements (10) can be changed by moving the drive (11). The position of the expansion elements (10) in the retracted state can be seen from FIG. 4, in FIG. 5, with the piston rod of the drive (11) extended, the position of the expansion elements (10 and 10 ') in the tensioned state. The four spreading elements (10) act along the edges of the box sack, as was shown in the schematic view in FIG. 10. In Figure 10, the expansion elements (10 and 10 ') have a circular cross section. However, the cross section of these elements does not have to be circular, for example in FIG. 12 a spreading element (10) is shown which was made from an angular profile.

Actuable clamps (12) are attached to the expansion elements (10). It is actuated via a lever system (40) by a drive (41), which was shown again in FIG. 11 as a pneumatic drive.

In a preferred embodiment of the device according to the invention, the edge of the sack is held in the vicinity of each edge of the sack (1) by two actuatable clamps (12 ', 12 ") which are connected to the lever system (40) via an angle piece (42) such an embodiment is shown as a detail in Figure 12. The actuatable clamps (12) or (12 ', 12 ") are attached to the expansion elements (10) at such a height that they just clamp the upper edge of the bag (1) can. In order to ensure that the sack is held in the clamps (12) or (12 ', 12 ") even when the spreading device (9) is moving, it is expedient for the drives (41) and the fixed points of the lever system (40) with the spreading elements Otherwise there is a risk that the clamping property of the clamps (12) could be canceled if the expansion device (9) is folded in. Furthermore, it is necessary that the Spreading elements (10) are longer than the height of the bags used. This is the only way that when the spreader device is retracted, the later insertion of the box bag spanned in the spreader device (9) into the large container (14) can be carried out without difficulty.

In a preferred embodiment of the device according to the invention, knives (18) which can be actuated are provided on each expansion element (10) at the level of the upper edge of the clamped sack. A precise arrangement is shown in FIG. 12; here the knife (18) acts directly through a slot in the expansion element (10). The knives (18) are also connected to drives (44) via lever systems (43). These drives, via the lever systems, enable the knives (18) to be swung out and the upper edge of the sack to be cut into the edges at a predetermined length.

In FIG. 11, a transfer system (19) is also provided, which consists of a drive (20) and associated lever systems (21) as well as pivotable swords (22). For the sake of clarity, FIG. 11 shows only two of these lever systems and two of the swords which can act on the upper edge of the sack. The swords (22) are elongated, ruler-like structures which allow the film material to be transferred under the holding devices (17) of the large container (14). The large container (14) in FIG. 11 has holding devices in the form of long leaf springs (17) on its upper edge, which are capable of resiliently holding the cut edge of the box bag (1). The large container (14) can be used for transferring or receiving the box bag (1) by a movement device, not shown, such as a roller conveyor or the like can be transferred to the exact location of the handover. This exact location can e.g. be fixed by suitable stops or the like. It is not imperative that this transfer location, as shown in Figure 11, be within the actual device, i.e. between the rail track (5) and the pulling device (7) and below the spreading device (9). A handover location at another location would also be possible. It would only have to be ensured that the movement device (13) of the expansion device (9) can carry out corresponding movements to another transfer location.

The device shown and described has a number of drives. They have mostly been shown in the figures as pneumatically operated movement devices. Since they usually only have to perform a reciprocating movement, such a type of drive should be particularly simple and at least prone to failure. However, there is also the possibility of these movements, e.g. by electric servo motors e.g. to be carried out in connection with gears or tooth chains or the like.

For reasons of simplification, the pneumatic control lines to the drives and the required control system have not been shown. Such control systems are known in principle. They are to be specified or programmed without further ado according to the information given for the procedure. The same applies to measuring devices such as Light barriers or the like, which must ensure the sequence of the method and correct operation of the device.

Claims (8)

1. A process for the insertion of bags made of flexible packaging material (1) into large box- shaped containers (14), wherein the bags are automatically received, retained and inserted into the container by a spreading device (9) characterised in that box-shaped bags (1) are inserted in containers (14) with a capacity of more than 100 liters and that the clamping of a box-shaped bag (1) takes place at at least four clamping points (3,3', 4,4') of a rolling carriage (2) in such a way that two opposing side faces of the bag are extended, whilst the other two side faces and the bottom of the bag (1) remain folded together, the rolling carriage (2) equipped in this way with a bag is stored on a first magazine track (5) and transported by a pushing device (27) up against a stop (6), as a result of extension of a pulling device (7) from the opposite side of the stop (6) the next extended side of the bag (1) is received from the rolling carriage (2) by means of actuable grippers (8, 8') mounted on the pulling device (7), and the bag (1) is extended at its upper open end as a result of subsequent retraction of the pulling device (7), a frame-type spreading device (9) is lowered, in the folded-in state, into the opened bag (1) so that, during subsequent tensioning of the spreading device (9) along the longitudinal edges of the bag (1), the latter is completely unfolded, in the tensioned state the bag (1) is freed, as a result of further lowering of the spreading device (9), from the remaining clamping points (3, 3') of the rolling carriage (2) and from the resilient grippers (8, 8'), the upper edge of the bag (1) is retained by actuable clamps (12) on the spreading device (9), the empty rolling carriage (2) is transported by a lifting device (15) onto a second magazine track (16) which allows the rolling carriage (2) to return to the first magazine track (5), the spreading device (9) is folded in and the bag, (1) retained by the clamps (12), is introduced, as a result of movement of the spreading device (9), into a large boxshaped container (14) and is applied over its full surface to the container walls as a result of renewed tensioning of the spreading device (9), the clamps (12) are released, and the bag is transferred to retaining devices (17) of the large container (14) before the spreading device (9) is folded in and retracted from the large container (14).

2. The process according to claim 1, characterised in that, after being received by clamps (12) or double-acting clamps (12', 12") of the spreading device (9), the bag (1) is incised at the upper ends of its edges as a result of the action of actuable knives (18) to the extent that foldable margins are obtained and that, after the bag has been introduced and tensioned in the large container (14) and after the clamps (12) or (12', 12") have been released, the foldable margins of the bag (1) are transferred to retaining devices (17) at the upper edges of the large container (14) by means of transfer devices (19).

3. The process according to claim 1 or 2, characterised in that, after being received by the clamps (12) of the spreading device (9), the bag (1) is lifted out of the receiving location as a result of movement of the spreading device (9), the upper ends of the edges are then severed in the tensioned state of the bag (1), the spreading device (9) is subsequently folded in and is then inserted into the large container (14) transported in the meantime into the effective range of the spreading device (9).

4. An apparatus for the insertion of bags (1) made of flexible packaging material into large box-shaped containers (14) by means of an spreading device (9) which automatically receives, retains and inserts the bags into the container comprising the following features:

a first magazine track (5) for guiding a plurality of rolling carriages (2), each rolling carriage having at least four clamping points (3,3', 4,4') which are at least so far apart from one another that two opposing sides of the bag (1) can be clamped, in the extendeded state, whilst the other two sides and the bottom can remain folded together,

a pushing device (27) for transporting the rolling carriages (2) on the first magazine track (5) up against a stop (6),

a lifting device (15) for transporting the rolling carriage (2), freed of the suspended bag, onto a second magazine track (16) on which the empty rolling carriages (2) can be guided back onto the first magazine track (5),

a pulling device (7) with actuable grippers (8, 8'), which is located opposite the magazine tracks (5, 16) on the other side of the stop (6) and which is capable by means of its grippers (8, 8') to receive the next extended side of a bag (1) from the rolling carriage (2) located against the stop (6) and of retaining it resiliently and, as a result of retraction, of extending the bag (1) at its upper edge,

a bag-spreading device (9), fastened to a moving device (13), with four spreading frames (10, 10') which are movable in joints and extend along the longitudinal edges of the tensioned bag (1) and which via a drive (11) can be tensioned and folded in so that the bag (1) hangs relaxed an actuable clamps (12) at least one of these clamps (12) being fastened to each frame part (10) of the spreading device,

as well as a rolling device which can bring the empty large containers (14) into the effective range of the moving device (13) of the spreading device (9) to a predetermined place

and, if appropriate, transfer devices (1) which can transfer the bag (1) extended in the larger container (14) to retaining devices (17) of the large container (14).

5. The apparatus according to claim 4, wherein two clamps (12', 12") are attached to each frame part (10) of the spreading device (9) in such a way that they can retain two longitudinal sides of the bag (1) in the vicinity of the common edge, and located in each case between them is a knife blade (18) which is attached to a moving device (43, 44) and which through a cutaway portion in the frame part (10) can incise the resulting longitudinal edge of the bag at its upper margin for a predetermined length.

6. The apparatus according to claim 5, wherein the large containers (14) have at their upper margin a plurality of retaining devices (17) which are capable of receiving from the transfer devices (19) and retaining the foldable edge strips of the box-shaped bag (1) which are produced as a result of use of the knife blades (18).

7. The apparatus according to claim 6, wherein the retaining devices (17) at the upper margins of the large container (14) have the form of leaf springs, and the transfer devices (19) fastened to the spreading device (9) have sword-like arms (22) which can press the foldable edge strips of the bag (1) under the leaf springs of the retaining device (17).

8. The apparatus according to one of claims 4 or 5, wherein by means of the moving device (13) the bag-spreading device (9) can be lifted so far above the insertion point of the bag that an empty large container (14) can be brought vertically underneath the bag-spreading device (9).

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