EP0116351B1 - Device for strapping a quadrangular package - Google Patents

Description

The invention relates to a device for strapping a cuboid packaged product, by means of two strapping tapes spanning the packaged product in mutually perpendicular cross-sectional planes, with two strap guide frames which, with respect to their frame plane, extend perpendicularly to a horizontal conveying plane which extends in their clear frame opening and serves to transport the packaged product are arranged and in which the strapping can be guided around the clear frame opening, and with a device assigned to each strap guide frame for inserting the strapping into the strap guide frame and for tensioning, closing and cutting the strapping wrapped around the packaged goods.

In a device of this type known from DE-A-2245505, two strapping machines, seen in the transport direction, are arranged one behind the other and with their frame planes parallel to one another and perpendicular to the transport direction. There is a turntable between the two strapping machines at the same height as the conveyor level. The quadratic packaged goods to be strapped are first fed to the first strapping machine in the transport direction and stopped. The cuboid is oriented in such a way that its central cross-sectional plane lies precisely in the frame plane of the tape guide frame. In this position, the strapping that is ready in the first strap guide frame is pulled out of the strap guide channel by means of an automatic sequence control, thereby laying it around the cuboid in this cross-sectional plane and tensioning, closing and cutting it off. After this first work cycle, the cuboid now provided with a strapping band is conveyed on to the turntable, where in a further work cycle the cuboid is rotated by 90 °. The cuboid rotated in this way finally arrives at the conveyor level of the second strapping machine, where it is provided with a further strapping band in a third work cycle analogous to the process that took place in the first strapping machine. The cuboid finally leaving the second strapping machine is provided in this way with two cross-strapping straps.

In this known device, a multi-stage workflow is therefore required to carry out the strapping process, in which the 90 ° rotation on the turntable as well as the multiple deceleration and re-acceleration of the packaged goods are extremely disadvantageous for the processing speed. In addition, the turntable with its associated drive forms both a cost and a possible disruption factor. Finally, the rotary table arranged between the two strapping machines also results in an increased space requirement for the device.

Furthermore, from the magazine _" Packing Revue", October 1959, p. 81, Fig. 4, an angular arrangement of two individual strapping machines is known. In this case, a turntable is replaced by a conveyor which stops the packaged goods and conveys them in a direction perpendicular to the previous direction of transport. The frame level of the strapping machine located on this second conveyor section is perpendicular to the frame level of the first strapping machine.

The space requirement of such a known angular arrangement is usually even greater than that of a straight-line machine arrangement. The other disadvantages are the same. The effort of a corner conveyor corresponds approximately to that of a turntable and the packaged goods have to be delayed three times and accelerated again until the two straps running crosswise are attached.

FR-PS 14 98 021 describes a device for cross-wise tying up parcels or stacks of paper, which works sequentially, without rotating the stack. Rotating strapping arms are arranged at two stations one behind the other in a transport direction, the axes of rotation of which run parallel to the conveying plane, specifically with one strapping arm in the transport direction and with the other transversely to the transport direction. Since the wire strand has to be twisted and deflected several times through 90 °, such an arrangement is not suitable for attaching strapping tapes. The space requirement of the device is considerable, continuous conveyor belts cannot be used because the rotating arms intersect the conveyor plane several times, and the packaged goods must be stopped at least twice and accelerated again.

Finally, from DE-AS 24 03 26T a device with only a single strapping machine is known, with which the two mutually perpendicular strapping processes are carried out. Here, the packaged goods also remain in one place during the processes. However, there are no stationary strap guide frames, but the strap guide frame is pivoted one after the other into the different strapping levels and the strap loop is guided perpendicularly to the loop plane above the packaged goods. The throughput required is considerably reduced due to the time required for this, because after all, both strapping processes must take place in succession. In addition, this device is not suitable for paper stacks or the like because one of the two strapping levels is parallel to the conveying level.

The invention has for its object to avoid a 90 ° rotation and a repeated stopping and accelerating of the packaged goods within the system and to increase the processing speed in a device for strapping a cuboid packaged goods of the type mentioned.

According to the invention, this object is achieved in that the frame planes of the two belt guide frames intersect perpendicularly along a common vertical center line.

It is therefore not necessary to turn the packaged goods when the strapping straps cross each other, because the orthogonal strapping directions are given automatically because of the perpendicular arrangement of the two frame levels. The entire cross strapping takes place in a one-step process. The packaged goods are only stopped once to put on both straps at the same time. This results in a particularly high processing speed. In addition, the device is simpler and shorter and therefore less prone to failure than the known devices.

If one of the two belt guide frames is arranged with its frame plane in the transport direction and the other transversely to it, the parts of the belt guide frame arranged in the transport direction that extend upward from the conveying plane stand in the way of the packaged goods during its transport. These parts therefore have to be temporarily moved to a funding release position.

In contrast, it is hereby proposed that the tape guide frames are arranged at an angle of 45 ° to the transport direction. This has the advantage that no parts of the belt guide frame protrude into the transport path of the packaged goods. A special conveyor can be installed upstream of the device to align the packaged goods in the necessary 45 ° position. This has the effect that the packaged goods initially aligned with the rectangular side surfaces parallel to the direction of transport run onto two conveyor belts conveying at different speeds and are thereby rotated by 45 ° before entering the device. However, the 45 ° rotation can also be carried out in the device itself, for example simply by providing stops on which the packaged goods run up and are thereby thrown around.

Since the strap guide frames are nested crosswise and penetrate each other, it is proposed for the mutual undisturbed guidance of the two strapping straps that strap guide channels are formed in the strap guide frames that cross each other at the interface of the frame levels, and that the respective inner strap guide channel closer to the packaged goods has separation points. In the simplest case, these are stationary gaps.

However, if these gaps are too wide, malfunctions can occur when the tape is inserted into the relevant tape guide channel. In order to avoid such difficulties, it is further proposed that at least a part of the inner tape guide channel adjoining a separation point be between a closed position in which the channel ends located on both sides of the separation point are flush with one another and an open position in which one between the two channel ends Gap is formed, are designed to be movable in the frame plane.

In any case, the separation points serve to unhinderedly pass the outer strapping across the inner strap guide channel when it is placed on the packaged goods. A pneumatic cylinder, for example, is suitable as a drive for a movement producing the passage opening. Since the width of the gap is usually small compared to the overall dimensions of the tape guide frame, the material elasticity of the tape guide frame is sufficient to allow this longitudinal movement, so that no separate joints are required on the tape guide frame.

• Fig.1 eine Vorrichtung zum Umreifen eines quaderförmigen Gegenstandes mit unter 45° zur Transportrichtung des Gegenstandes angeordneten Bandführungsrahmen,
• Fig. 2 eine schematische Darstellung sich kreuzender Bandführungskanäle mit Trennstellen des inneren Bandführungskanals im Kreuzungsbereich.

An embodiment of the invention is explained below with reference to the drawing. In detail shows

• 1 shows a device for strapping a cuboid-shaped object with a belt guide frame arranged at 45 ° to the transport direction of the object,
• Fig. 2 is a schematic representation of intersecting tape guide channels with separation points of the inner tape guide channel in the intersection area.

1, a device 1 for strapping a cuboid packaged product, namely a stack of newsprint 2, each has band guide frames 3, 3 'extending in a vertical frame plane. The two frame planes intersect along an imaginary vertical center line 4, through which the clear frame opening enclosed by the two tape guide frames 3, 3 'is divided into two parts of equal size. The horizontal angle enclosed between the two intersecting frame planes is 90 °.

In the clear frame opening of the two belt guide frames 3, 3 'extends a horizontal conveyor plane 5, which is formed by the surface of a table 6 carrying the two vertical belt guide frames 3, 3'.

The straight-line transport direction indicated by an arrow 7 runs from the front left to the rear right in the perspective illustration of FIG. 1. The frame planes of the two belt guide frames 3, 3 'are each arranged at an angle of 45 ° to this transport direction.

A press 8 is arranged above the belt guide frames 3, 3 '. It is provided with four press rams which can be extended vertically downward beyond the band guide frames 3, 3 'in the region of the free corners of the cross formed by the band guide frames 3 and 3'. These press punches engage the upper horizontal cuboid surface of the stack 2 in its strapping position in order to compress it if desired.

The two tape guide frames 3, 3 'are essentially in the form of a rectangle with rounded corner areas, the rectangular legs 9 and 10 of which are horizontal or extend vertically. The vertical rectangular legs 10 pass through the four corners of the square conveyor plane 5. The entire clear cross-section of the device 1 perpendicular to the direction of transport is therefore in the vertical direction due to the vertical length of the recutting leg 10 projecting above the conveying plane 5 and in the horizontal direction by the horizontal distance between the belt guide frame 3 on the one hand and the belt guide frame 3 'On the other hand belonging vertical rectangle leg 10 determined.

In the tape guide frame 3, 3 'laterally open (Fig. 2) or inward opening tape guide channels are formed. This allows the straps 12 and 12 'to emerge from the channels after the formation of a closed loop and to be retracted to narrow the loop. A device is arranged in the table 6 below the conveying plane 5, through which the strapping bands 12 and 12 'can be inserted into the band guide channels of the two band guide frames 3, 3'. This device also serves to pull the straps 12, 12 'out of the strap guide channel as soon as the stack 2 is in its strapping position provided on the conveying plane 5 and thereby to put it around the stack 2. In addition, the strapping is tensioned, closed and finally cut off by this device. For the passage of the strapping through the conveying plane 5 there are passage slots 13 arranged along the frame planes. In order to make this device, which contains two so-called sealing heads, easily accessible for maintenance purposes, the table 6 can be opened by means of a door on its side surface parallel to the direction of transport.

Conveyors 14 and 15 are connected to the two sides of the table 6 extending transversely to the transport direction, with the conveyor 14 transporting the stack 2 in the transport direction onto the conveying plane 5 into the strapping position 16 indicated by dash-dotted lines. Conversely, the conveyor 15 transports the strapped stack 2 out of the device 1. The stack 2 to be strapped must be fed to the device 1 with its vertical rectangular side faces 17 at an angle of 45 ° to the direction of transport, so that the strapping crosswise parallel to these rectangular side faces 17 can be done. However, if the stack 2 to be strapped is delivered from a possible previous processing stage with its rectangular side surfaces 17 parallel or perpendicular to the direction of transport, it is therefore necessary to rotate the object 2 by 45 ° before it enters the device 1. For this purpose, the conveyor 14 is provided in an area located upstream of the device 1 with two separate conveyor belts 18, 18 ', which move at such a different linear speed that the stack 2 is straight during its transport over the conveyor belts 18, 18' is rotated by 45 °.

Fig. 2 shows the special design of the tape guide channels. An outer band guide channel 20 is shown seen in the frame plane, the inner band guide channel 21, which is perpendicular thereto, lies in the plane of the drawing. Both channels are sunk into the conveyor plane 5 so far that the upper edge of the lower horizontal leg of the inner belt guide frame 21 is at the level of the conveyor plane 5. A feed channel 22 is additionally shown for the belt guide frame 21. Both tape guide channels 20 and 21 have a U-shaped cross section with the opening on the side.

While the outer band guide channel 20 can consist of one piece, the inner band guide channel 21 is divided into two U-shaped halves 21 a and 21 b, the leg ends lying directly against one another at a separation point 23 and forming a permanent gap 24 below. By means of a pneumatic cylinder 25, which engages the left half 21b of the inner band guide channel at the top left, this half 21b can be deformed in such a way that it assumes the position shown in broken lines, the separation point 23 expanding into a gap 26. The lower leg of the half 21 b is firm.

When the straps 12 and 12 'are pushed into the strap guide channels 21 and 20 during operation and have formed complete loops, actuators, not shown, push the straps laterally out of the channels. At the same time, the pneumatic cylinder 25 opens the gap 26, so that when the strapping is then simultaneously withdrawn, the strapping 12 'can cross the strap guide channel 21 freely above and below and, if the loop is further reduced, can lay against the packaged goods. To insert the strapping in the next operation, the gap 26 is closed again.

Claims (4)

1. Device (1) for banding a parallelepipedic package (2) by means of two mutually crossing banding tapes (12,12') binding around the package (2) in mutually perpendicular cross-sectional planes, with two tape-guide frames (3, 3') which are arranged, as regards their frame plane, perpendicularly of a horizontal conveyor plane (5) extending in their clear frame opening and serving for the transport of the package (2) and in each of which the banding tape (12,12') can be conducted around the clear frame opening, and with an apparatus allocated to each tape guide frame (3, 3') for pushing the banding tape into the tape guide frame and for tightening, sealing and cutting off the banding tape (12, 12') laid around the package (2), characterised in that the frame planes of the two tape guide frames (3, 3') intersect one another perpendicularly along a common vertical centre line (4).

2. Device according to Claim 1, characterised in that the tape guide frames (3, 3') are arranged at an angle of 45° to the direction of transport.

3. Device according to Claim 1, characterised in that in the tape guide frames (3, 3') there are formed tape guide passages (20, 21) which cross one another at the point of intersection of the frame planes, and in that the inner tape guide passage (21) lying closer to the package in each case comprises points (23) of separation.

4. Device according to Claim 3, characterised in that at least one part (21 b) of the inner tape guide passage (21) adjoining a point (23) of separation is made movable in the plane of the frame between a closed position in which the passage ends placed on the two sides of the point (23) of separation lie in alignment against one another and an open position in which a gap (26) is formed between the two passage ends.

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