Method for wrapping bands around objects, and corresponding machines

Abstract

In a method for wrapping a band around at least one object of at least one object, in which the at least one object is wrapped with a band, wherein the band in the form of an object-band loop is arranged around the at least one object in such a manner that at least two sections of the band are made to overlap and are connected together, wherein in an area in which the at least two band sections are made to overlap, a counter-pressure plate is introduced between the at least one object and the band, and the at least two overlapping band sections are pressed against the counter-pressure plate to connect them, prior to the introduction of the counter-pressure plate the band is passed through a band guiding device and/or positioned such that a defined free space is created for introducing the counter-pressure plate.

Claims

1. A device for introducing a counter-pressure plate between a band and a conveyor level in a banding and/or strapping machine, comprising: a) A rear holding device which can hold a beginning of the band and b) the conveyor level with an opening which is located above the rear holding device and on which an object can be moved in a conveying direction, wherein in the movement of the object on the conveyor level in the conveying direction the band, the beginning of which is held by the rear holding device and which projects through the opening into the conveyor level is drawn in the conveying direction through the opening in the conveyor level, wherein c) a band guiding device is present, which is movable in the conveying direction in a region between the band and the conveyor level and positions or guides the band beneath the conveyor level, creating a free space for inserting the counter-pressure plate between the band and conveyor level.

2. A device for wrapping bands around an object, comprising the following parts: a) A device for introducing a counter-pressure plate according to claim 1 b) A lowerable band guide which can be located in a level above the objects and which may be located below a conveying level and in both positions can guide the band and in a starting position tensions the band between the lowerable band guide in the level above the objects and the rear holding device c) A counter-pressure plate that can be brought below the conveyor level between the band and the underside of the object and removed again d) A front holding device that can fix the band at a point in front of the rear holding device e) A loop puller that can pull the band from the band guide, in the position beneath the conveyor level, starting in the conveying direction, into a loop f) A severing device that can sever the band, preferably directly behind the rear holding device, and g) A joining device that can connect the band to the band in an overlapping region.

3. The device for wrapping a band around at least one object according to claim 2, which comprises also a band tensioner which regulates the band tension.

4. The device for wrapping a band around at least one object according to claim 3, wherein the band tensioner is electrically controllable.

5. The device for wrapping a band around at least one object according to claim 2, wherein the device comprises several supply rolls for bands.

6. The device for wrapping a band around at least one object according to claim 5, wherein the supply rolls are coordinated with one another by a supply roll controller in such a manner that a supply roll can be changed in each case while bands are being drawn off of another supply roll.

7. The device for wrapping a band around at least one object according to claim 6, wherein the supply roll controller and the band storage unit controller are coordinated with one another or integrated into a mutual control unit.

8. The device for wrapping a band around at least one object according to claim 6, wherein the connecting device and the supply roll controller are coordinated with one another in such a manner that upon welding of one end of a band with the beginning of a band, the one end of a band and the beginning of a band overlap by less than 1 cm.

9. The device for wrapping a band around at least one object according to claim 2, which comprises a band storage unit which allows the banding process to continue running for a certain time without braking or only slowing, without the band on the other side of the band storage unit moving because of the banding process.

10. The device for wrapping a band around at least one object according to claim 9, wherein the band storage unit is controlled by a band storage unit controller.

11. The device for wrapping a band around at least one object according to claim 2, which comprises a connecting device with which a band end of one band on a first supply roll can be connected to the beginning of a band on a second supply roll.

12. The device for wrapping a band around at least one object according to claim 11, wherein the connecting device involves a welding device.

13. The device for wrapping a band around at least one object according to claim 2, wherein the device comprises a printer unit for imprinting the band before and/or during the banding or strapping process, wherein the printer unit is preferably a thermal transfer printer.

14. The device for wrapping a band around at least one object according to claim 13, wherein the printer unit is mounted after a band storage unit in a band movement direction.

15. The device for wrapping a band around at least one object according to claim 14, wherein the printer unit is freely accessible.

16. The device for wrapping a band around at least one object according to claim 2, wherein at least one of the drives used is realized as at least one servomotor.

17. The device for wrapping a band around at least one object according to claim 16, wherein at least one servomotor that drives the band can also be used as an abrasion-free brake.

18. The device for wrapping a band around at least one object according to claim 16, wherein the servomotor can be controlled by remote access.

19. The device for wrapping a band around at least one object according to claim 2, wherein the device comprises at least one sensor.

20. The device for wrapping a band around at least one object according to claim 19, wherein the sensor data can be read by remote access.

21. The device for wrapping a band around at least one object according to claim 19, wherein the sensor can measure the pressure on the packets and/or the tension on the band and/or the presence of supply rolls and/or the quality of the imprinting and/or another property of the device, the packet and/or the band.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) The drawings used for explaining the exemplified embodiments show:

(2) FIG. 1 Starting situation of the banding process as an example of a method for wrapping a band around an object.

(3) FIG. 2 Protuberance of the band due to an object

(4) FIG. 3 Introduction of the counter-pressure plate

(5) FIG. 4 Release of the beginning of the band

(6) FIG. 5 Starting position of the loop puller

(7) FIG. 6 Fixation and severing of the loop

(8) FIG. 7 Spreading out of the loop

(9) FIG. 8 Connecting

(10) FIG. 9 Release and transport away of the object

(11) FIG. 10 Possible resting positions of various components

(12) FIG. 11 A device for wrapping a band around at least one object

(13) Basically in the figures the same parts are provided with the same reference symbols.

METHODS OF EXECUTING THE INVENTION

(14) FIG. 1 shows the initial situation of a banding method according to the invention as an example of a method for wrapping a band around an object. The method can also be performed analogously as a strapping method. An object 6, e.g., a stack of paper or cardboard, moves on a conveyor level 1. A band 3 is held in a rear holding device 2 lying below the conveyor level 1. From there it moves to a point in a level above the object, where in this case a band tensioner 5 is installed. In this example a band guide 4 is located without contact with the band in the horizontal direction between the band tensioner 5 and the rear holding device 2 and on a similar level as the band tensioner 5. In another embodiment, contact exists between the band guide 4 and the band 3 in this situation. If this is the case, the band guide 4 can hold the band in the level above the object. It is also possible that instead of the band tensioner 5 a deflector roller or another component that can hold the band in the level above the object 6 may be used. The band comes from a band source which is not shown and which is preferably a supply roll. From there the band is guided over the band tensioner 5, possibly over the band guide 4, to the rear holding device 2. In between, guide rollers and additional components can be used to guide and handle the band in the desired way. For example, it could also be imprinted.

(15) The band tensioner creates or maintains a band tension lower than that which the closed, finished band loop, which in the case of banding is the banderole, shall finally have (target tension).

(16) FIG. 2 shows the situation at a time shortly after the situation in FIG. 1. The object 6 has reached the band, tightened between the rear holding device 2 and the band tensioner 5, and has bulged it out because of its movement in the conveying direction. A band guiding device 7 was brought into the band plane and also moves in the conveying direction. Since the object 6 has passed the position of the band guide 4 in the horizontal direction, the band guide 4 now lowers.

(17) FIG. 3 shows the result of these movements. This is the situation at a time after that shown situation in FIG. 2. The band guide 4 has now pressed or guided the band 3 behind the object 6 below the conveyor level 1. The band guiding device 7 has guided the band beneath the conveyor level 1 such that a free space 17 has formed between the band 3 and the conveyor level 1 respectively the object 6. The counter-pressure plate 9 was introduced into this free space. After this has been done, the band guiding device 7 can be removed again. For this purpose the front holding device 8 now moves upward to clamp the band 3 tightly between itself and the counter-pressure plate 9.

(18) While the band guide 4 presses the band below the conveyor level 1, the band tension is controlled to be the target tension or an even higher tension by the band tensioner 5.

(19) The situation at a later time point is shown in FIG. 4. The band 3 is held by the front holding device 8. Therefore the rear holding device 2 can release the band. Thereby, the two jaws of the rear holding device 2 divide into an upper jaw 2b and a lower jaw 2a. A band start holding device 10 moves upward and leads thereby the beginning of the band, which is free at this stage, towards the counter-pressure plate 9.

(20) In FIG. 5 the band 3 is pressed against the counter-pressure plate 9 by the band start holding device 10 and the front holding device 8 at this stage. However, the band section fixed in this way is only the beginning of the band. Another part of the band travels over or through the band guide 4. In a suitable cutout of the band guide 4, a loop puller 11 is introduced, now located between the band guide 4 and the band 3. It moves in the conveying direction and thus draws the band 3 along with it. The band tension is kept at or somewhat above the high target tension value by the band tensioner 5.

(21) FIG. 6 shows the loop formed by the movement of the loop puller 11. The upper jaw 2b of the rear holding device is introduced into the loop and moves upward. The lower jaw 2a of the rear holding device also moves upward. The band 3 is now clamped twice in the area of the loop: Once at a point at the upper side of the loop between the counter-pressure plate 9 and the upper jaw 2b. This is the additional holding device. A second time, the band 3 is clamped in the area of the lower side of the loop between the upper jaw 2b and the lower jaw 2a. This is the rear holding device. A severing device 12, which may be a knife, for example, severs the band shortly in front of the rear holding device. (Front and back are defined relative to the conveying direction).

(22) The following steps are shown in FIG. 7. After the loop was opened by the severing of the band 3, the loop puller 11 moves on in the conveying direction and thus stretches out the loop. A joining device 13 is brought to the band 3 in the area of the counter-pressure plate 9. The band 3 now overlaps with itself in this area. The band guide 4 can be raised again at this stage and returns to the position in a level above the object 6. At this stage, the band tension is reduced again by the band tensioner 5.

(23) In FIG. 8 the connection between the overlapping band sections is just being produced by the joining device 13. The band 3 no longer needs to be held against the counter-pressure plate 9 and therefore the front holding device 8 releases it, the band start holding device 10 and the rear holding device 2 move, both jaws 2a and 2b pressed together and thereby holding the new beginning of the band, away from the counter-pressure plate 9, which releases the additional holding device. The counter-pressure plate 9 can be removed in the following, too.

(24) FIG. 9 shows the result: The object 6 with the band wrapped around it, i.e. the banded object in the case of banding, is transported away. Here, this takes place in the conveying direction, too. The mechanism for wrapping a band around an object (e.g., a banding or strapping mechanism) is in the same configuration as in FIG. 1. An additional object 6 moves in the conveying direction toward the tightened band 3 and the process can start from the beginning.

(25) FIG. 10 shows possible resting positions of the components, which move into the band plane and which are removed from it again over the course of the process. A resting position here is defined as the position in which the components are not performing any task or not their primary task. Naturally other components may be making such movements. FIG. 10 is a sketch of the top view on the conveyor level 1. The conveyor level 1 and all components shown are illustrated as transparent. Only their outlines are shown.

(26) The conveyor level 1 has an opening 14, and this has a front edge 15. The conveying direction 16, which defines the direction for front and back, is shown by an arrow. On the right-hand side of the opening 14, the counter-pressure plate 9 is shown in its resting position. Below the counter-pressure plate 9, parts of the different holding devices are located: The front holding device 8, the upper jaw of the rear holding device 2b and the band start holding device 10.

(27) During the process, all of these components are never in the resting position simultaneously: The upper jaw of the rear holding device 2b is moved into a situation in the resting position in which at least the front holding device 8 and the counter-pressure plate 9 are being used. At the time when the counter-pressure plate 9 is removed, the upper jaw of the rear holding device 2b is again in use for holding the next beginning of the band.

(28) In this embodiment, on the left-hand side of the opening, the band guiding device 7 and the loop puller 11 are shown as hooks. These can be brought into the band plane by a pivoting movement and then pushed or pulled in the conveying direction.

(29) Naturally, it does not matter which of the components is arranged on which side of the opening. Also, the sizes of the objects and their relationships are selected only for purposes of illustration. It is only necessary to make sure that the various holding devices are suitably arranged, so that the counter-pressure plate can serve as the complement to a clamp if this solution is desired.

(30) FIG. 11 depicts a device for wrapping a band around at least one object.

(31) The device comprises two supply rolls 23a, 23b for bands which are coordinated with one another by a supply roll controller 21 in such a manner that a supply roll 23a, 23b can be changed in each case while bands are being drawn off of another supply roll 23b, 23a. The device comprises a band storage unit 19 which makes it possible for the banding process to continue running for a certain time without braking or only slowing, without the band on the other side of the band storage unit 19 moving because of the banding process. The band storage unit 19 is band guidance over three deflecting rollers, one of which is movable relative to the other two. The device comprises a welding device 22, which is an embodiment of a connecting device, with which a band end of one band on a first supply roll 23a can be connected to the beginning of a band on a second supply roll 23b.

(32) The device comprises a printer unit 20 for imprinting the band before and/or during the banding or strapping process. The printer unit 20 is preferably mounted after a band storage unit in the band travel direction.

(33) The band tensioner 5 comprises at least two elements between which the band moves. One of the elements is a roller that rotates at a certain speed. To produce and control the desired speed, a special motor is used. It is a servomotor 18 that drives the band.

(34) The device comprises a sensor 24. It can measure the presence of supply rolls.

(35) However, the method described in the preceding and the devices shown are to be understood as merely illustrative examples, which can be modified as needed within the scope of the present invention.

(36) For example, it is possible that the band guiding device 7 will initially guide the band 3 further in the conveying direction than the object 6 and the object 6 will only reach the position shown in FIG. 3 at a later time.

(37) The band guide 4 can already occupy a lower position at an earlier time. However, it should not collide with the object 6. The band guiding device 7 can be removed before or after pressing on the front holding device 8.

(38) The front holding device 8 need not necessarily use the counter-pressure plate 9 as a second clamping jaw, but could have a separate, second clamping jaw.

(39) The band holding device 10 may also be dispensed with. In this case the path along which the loop puller 11 moves can be adapted sufficiently.

(40) The band guide 11 can be designed such that the loop starts and ends at it. For this purpose the band 3 may be held on the band guide 4 with a suitable device. Alternatively, the loop may start at the band guide 4 and end at the corner of the object 6, the edge of the counter-pressure plate 9 or the edge of the band start holding device 10. The preferred solution is for the corner of the object 6 to delimit the loop, since in this case the band 3 will lie tightly against the object 6.

(41) In the embodiment shown, the additional holding device is formed by the upper jaw 2b of the rear holding device and the counter-pressure plate 9. However, the additional holding device may also consist of two jaws of its own or of one jaw and the counter-pressure plate 9.

(42) The placement of the band tensioner 5 is also variable. A deflecting roller can hold the band in the place above the object shown here. However, it is also possible for the band 3 to be guided through the band guide 4 in such a way that the band guide 4 can hold the band 3 up without further aids. The band tension could then be placed at any point whatsoever between the band source and the band guide 4. The band tensioner may also be integrated into the band source in that, for example, it controls the rotation of a supply roll.

(43) The device for introducing a counter-pressure plate according to the invention is shown in FIG. 3. Then in FIG. 4 it is clear how the band guiding device 7 fulfills its task of enabling the introduction of a counter-pressure plate 9. The band tensioner 5 and the band guide 4 are not part of this device, nor are the band 3 nor the object 6.