Transport arrangement for transporting containers, and forming system

Abstract

The invention relates to a transport arrangement for transporting containers, comprising a separating device (4) which has a conveyor lane (7) formed from two conveyor rollers (6) spaced apart from one another in a transverse direction (Q) and designed to be rotatable in opposite directions, and a metering device (8) connected upstream of the conveyor lane (7). According to the invention, the metering device (8) is designed to transfer a predefined number of containers to the separating device (4) in a weight-based manner.

Description

[0001] Transport arrangement for the transport of containers and forming plant

[0002] Description:

[0003] The invention relates to a transport arrangement for transporting containers, comprising a singulation device which has a conveying lane formed by two conveyor rollers spaced apart from each other in a transverse direction and arranged to rotate in opposite directions, and a metering device upstream of the conveying lane. In this context, reference is made to the intended transport path of the transport arrangement, such that a metering device is arranged upstream of the singulation device along the transport path.

[0004] Such transport arrangements are generally known from the prior art and serve to align containers from an initially disordered state and arrange them one behind the other so that they can be fed to a downstream processing machine. For this purpose, the transport arrangement includes a singulation device, which is usually also referred to as a roller sorter, since the rotary movement of the conveyor rollers allows for both singulation and sorting of the containers during their movement along the conveyor lane.

[0005] The invention relates in particular to transport arrangements from the beverage industry, such that the containers are primarily preforms, which are formed into beverage containers using blow molding machines or stretch blow molding machines. This formation typically occurs through plastic deformation of the preforms, resulting in a material of thermoplastic, particularly polyethylene terephthalate (PET), which can then be heated, softened, and subsequently expanded into a beverage container, for example, by applying internal pressure. The beverage containers are primarily beverage bottles.

[0006] To ensure an uninterrupted manufacturing process, the forming machine must be continuously fed with preforms. These are usually pre-manufactured and must first be separated and aligned from a collection container before being fed to the forming machine.

[0007] Against this background, the transport arrangement typically includes a so-called inclined conveyor, via which the preforms are removed from the collection container and transported upwards in a vertical direction. From there, the preforms then enter the conveyor lane of the singulation device via a hopper inlet, the width of which is defined by the distance between the two conveyor rollers of the corresponding pair of conveyor rollers.

[0008] It is important to note that the preforms, in a singulated and sorted state, rest on the conveyor rollers with their so-called neck rings and are continuously thrown upwards by the counter-rotating conveyor rollers. The neck ring is a section of the preform located below the opening of the preform and protrudes radially outwards. An external thread is typically provided above the neck ring, allowing a cap to be screwed onto the preform or the resulting container. Accordingly, the opening of the container is a section of the preform that does not undergo plastic deformation. The area below the neck ring is the section that is subjected to plastic deformation.

[0009] The conveyor rollers are arranged essentially parallel to each other, whereby "essentially parallel" within the scope of the invention means that the axes of rotation of the conveyor rollers may only deviate from each other by a maximum of 5°. Due to the upward throwing motion of the conveyor rollers, the preforms align themselves such that the container opening points upwards, while the area of ​​the preforms to be subsequently formed is located between the conveyor rollers in the conveying lane. Furthermore, by tilting the conveyor rollers with respect to a vertical axis, transport in the conveying direction is effected.

[0010] Corresponding designs are known, for example, from EP 2 892 661 A1 or from WO 2011 / 069268 A1.

[0011] The inclined conveyor, responsible for feeding the preforms into the singulation unit, typically has several pockets through which the preforms are taken from the collection container and fed into the singulation unit. Accordingly, the feeding usually occurs in batches, meaning that within the singulation unit, the preforms must be arranged in a row, starting from this essentially unsorted state. Since this can lead to jamming or jamming of the preforms, or to individual preforms not being sorted and thus having to be removed from the singulation unit again, a so-called dosing device, arranged between the inclined conveyor and the singulation unit, has proven advantageous in practice.This essentially consists of a circulating conveyor belt on which the preforms initially rest and can align themselves somewhat towards each other.

[0012] While this design has proven effective, it only partially mitigates the problem. It is still possible that at certain intervals, too many or too few preforms are fed into the transport system of the singulation unit, making continuous feeding and singulation problematic, especially with high machine outputs. Particularly with machine outputs exceeding 80,000 preforms per hour, the existing solution has proven to offer only partially satisfactory results.

[0013] Against this background, the invention is based on the objective of providing a transport arrangement which enables a continuous and reliable supply of containers, in particular of preforms, into a forming machine, even with high machine outputs.

[0014] The subject and solution of this problem is a transport arrangement according to claim 1. According to the invention, the dosing device is configured to transfer a predefined number of containers to the singulation device based on their weight. Accordingly, the dosing device is designed as a so-called weighing system, whereby, within the scope of the invention, a weighing system does not necessarily mean that active measurement of the containers' weight is required. Rather, the dosing device is configured to transfer a number of containers to the singulation device solely based on a predefined weight. The number of containers can be determined from the weight, since the containers generally have a fixed weight.In the case of preforms, the weight is typically between 5 and 50 g, so even slight deviations still provide a reliable indication of the number of containers within the dosing unit. Once a certain number of containers is reached, they can be released and transferred to the singulation unit.

[0015] According to a preferred embodiment of the invention, the predefined number of containers is between 6 and 14, in particular between 8 and 12. Such an embodiment is particularly advantageous when the containers are preforms.

[0016] According to a preferred embodiment of the invention, the dosing device comprises at least one dosing chamber for receiving containers, wherein the dosing chamber has an actuating section movable between an open and closed position. Thus, the containers initially enter the dosing chamber of the dosing device from, for example, an inclined conveyor and accumulate there until the predefined number of containers is reached. As soon as this number is reached, the actuating section opens, or rather, the actuating section is moved from the closed state to the open state. This then allows the containers to enter the singulation device, whereby the predetermined quantity of containers ensures that they can be sorted reliably and with as few disruptions as possible between the conveyor rollers.

[0017] The actuating section can be a pivoting flap. In the simplest case, this flap, or actuating section, is connected to one or more spring elements designed to support the weight of a predefined number of containers. As the weight increases, the spring element deforms, and when the predefined number is reached, the actuating section is released to the point where the containers can be emptied into the conveyor lane of the singulation unit. It is essential, however, to ensure that the containers are emptied as completely as possible from the dosing chamber before the actuating section returns to its closed position. Of course, other designs are also conceivable; for example, the actuating section could also be a linearly adjustable slide.

[0018] According to a further development of the invention, the dosing device has at least three, preferably at least four, and particularly preferably at least five, dosing chambers. It should be noted that while the inclusion of a weight-based releasing dosing chamber can limit the number of containers fed, this feeding still occurs in a more or less discontinuous manner, making it desirable to enable the feeding process to be as continuous as possible. Against this background, a plurality of dosing chambers can now be provided, each configured to hold a predefined number of containers. Accordingly, it is not necessary to wait after moving a dosing chamber from the open to the closed position until the predefined number of containers is reached again within the dosing chamber.Rather, the individual dosing chambers can release the containers either freely from one another or in a defined manner relative to each other, so that a large number of transfers of the dosing chambers into an open position can take place within a certain period of time.

[0019] According to a preferred embodiment, each metering chamber has an actuating section that connects to a common discharge section. The underlying idea is that the conveying lane formed by the conveyor rollers is relatively narrow, so theoretically the metering chambers would have to be arranged longitudinally one behind the other to allow them to be fed into the conveying lane of the singulation device. However, this would require a relatively long conveying lane to properly align and sort all the containers. Therefore, it is advantageous to arrange the metering chambers either transversely to the conveying lane or along a circumference relative to each other. Such an arrangement is only practical if a certain number of metering chambers are required.The control sections are arranged in such a way that they are connected to each other via a common discharge section. Accordingly, the containers from the metering chamber first enter the discharge section, which is preferably located above the conveying lane and always allows entry into the conveying lane, regardless of whether the metering chamber is in the open position.

[0020] A further development of the invention provides that, upon reaching the predefined number of containers in each dosing chamber, or at least the control sections of at least two dosing chambers upon reaching the predefined number of containers simultaneously, are moved into the open position. Accordingly, the dosing chambers can be operated in two different ways. In the first variant, the predefined number of containers always refers to the dosing chambers, so that a certain number of containers must be present in each dosing chamber before they can be transferred to the singulation device. This can be achieved, for example, by the embodiment already described above, in which the control sections of the dosing chamber, for example,The containers are held in the closed position by spring tension, and the actuating section moves to the open position solely based on weight, determined by the predefined number of containers. According to this design, the containers are released into the dosing chambers as independently as possible, or a dosing chamber is held in place. Alternatively, the dosing chambers can be arranged such that only one dosing chamber can be released at a time, while the other dosing chambers remain in the closed position.

[0021] According to a second variant, several dosing chambers can also be moved into the open position simultaneously, provided that the total number of containers in the dosing chambers corresponds to the predefined number of containers. For example, if the predefined number of containers is ten, and there are four containers in one dosing chamber and six in another, both dosing chambers can be moved into the open position at the same time, thus releasing the predefined number of containers.

[0022] Preferably, the invention provides that the dosing device comprises a control unit and a weighing unit connected to the control unit and assigned to each dosing chamber(s), wherein the control unit is configured to determine the number of containers arranged in the dosing chamber(s) based on the weight determined by the weighing unit and to move the respective actuating section to an open position based on the determined number. Accordingly, release is thus based on a measurement of the weight in the dosing chambers. The actuating sections can then be connected to corresponding actuators, which effect the fastest possible actuating movement between the open and closed positions or vice versa.This design has the advantage that the number of predefined containers can be changed as easily as possible without any mechanical changes to the dosing chambers or the dosing device.

[0023] According to a further development of the invention, the metering device has a particularly common inlet section which connects to the outlet of an inclined conveyor. The metering device is then preferably arranged vertically between the highest point of the inclined conveyor and the singulation device, the inclined conveyor accordingly defining the highest point of the transport device.

[0024] According to further training, the containers are preforms, in particular plastic preforms.

[0025] A further development of the invention provides that the singulation device includes a container separator which is connected via a return device to the metering device, in particular to the feed section of the metering device. Thus, if individual containers cannot be sorted into the conveyor lane in a suitable manner within the singulation device, it is possible to remove these containers from the transport path by means of the container separator and then feed them back to the metering device.

[0026] The invention further relates to a forming system comprising a forming machine for the plastic forming of plastic preforms into beverage containers and a transport arrangement according to the invention upstream of the forming machine. The forming machine is preferably a blow molding machine, in particular a stretch blow molding machine.

[0027] The blow molding machine, or stretch blow molding machine, preferably has a rotatable carrier with a plurality of circumferentially arranged blow molds in which the plastic preforms can be formed into beverage containers. A heating device is preferably located upstream of the rotatable carrier, in which the containers are heated by radiation so that they can then be easily plastically deformed. The transport arrangement then preferably connects directly to an infeed assembly of the heating device. For this purpose, the transport arrangement, following the singulation device, has either an air-controlled linear guide or a feed chute, which connects to a sawtooth star of the infeed assembly. The sawtooth star positions the containers at a predetermined division, through which they can then be fed to the heating device.Accordingly, the containers within the transport arrangement are without a defined division, while the sawtooth star of the inlet arrangement ensures a predefined division throughout the entire manufacturing process and usually also in the subsequent filling process.

[0028] The invention further relates to a method for operating a transport arrangement and / or a forming plant according to the invention, wherein containers, in particular preforms, are fed to the metering device and, based on weight, transferred to the singulation device after reaching a predefined number. In principle, all features described in connection with the transport arrangement or forming plant can also be adopted for the method.

[0029] Preferably, the containers are weighed and the number of containers is determined based on the weight. If the predefined number of containers is reached or exceeded, the containers can then be transferred to the singulation device, particularly by means of the measures described above.

[0030] Preferably, the containers are plastically deformed after singulation. This is achieved in particular by blow molding or stretch blow molding. Between singulation and deformation, the containers can also be heated, which softens the container material.

[0031] Furthermore, it is also conceivable that a conveying speed for transporting the containers in the singulation unit could be set based on the determined number of containers. For example, a simple control process could be implemented, establishing a relationship between the number of containers and the conveying speed. Of course, it is also possible to incorporate a more complex control process. This could involve, for instance, the inclined conveyor, allowing the number of containers fed to the dosing unit to be adjusted. In this context, a previously described control device could also be configured to control and / or regulate the conveying speed of the singulation unit based on the determined number of containers.

[0032] The invention is explained in more detail below using an exemplary embodiment. The figures show...

[0033] Fig. 1 shows a schematic representation of a transport arrangement according to the prior art.

[0034] Fig. 2 shows a schematic representation of a transport system according to the invention.

[0035] Figs. 3, 4 show a top view of a section of the transport system according to the invention in various states.

[0036] Fig. 1 shows a transport arrangement for transporting preforms 1, which are made of a thermoplastic material, in particular polyethylene terephthalate (PET), and which are formed into beverage bottles within a stretch blow molding machine (not shown). These preforms 1 are initially located within a collection container 2 and from there are conveyed via an inclined conveyor 3 to a singulation device 4, which, according to Fig. 1, is designed as a so-called roller sorter and aligns and arranges the preforms 1 one after the other along a transport path T so that they can be fed to the downstream stretch blow molding machine in a predetermined arrangement.

[0037] The basic principle of this roller sorter can be seen particularly in a comparative illustration with Fig. 3. Accordingly, the singulation device 4 has two counter-rotating conveyor rollers 6, whose axes of rotation D are arranged essentially parallel to each other and which are spaced apart from each other in the transverse direction Q such that a conveying lane 7 is formed between the two conveyor rollers 6. The preforms 1, with a neck ring (not shown in detail), rest on the conveyor rollers 6, so that the container body, which is later plastically formed during stretch blow molding, is located between the conveyor rollers 6 within the conveying lane 7. Due to the counter-rotating conveyor rollers 6, the preforms 1 are continuously thrown upwards and then, in combination with the slight inclination of the conveyor rollers 6, conveyed along the transport path T.

[0038] Starting from the singulation unit 4, the preforms 1 then enter an air conveying section 5 and from there into the actual stretch blow molding machine.

[0039] Since the inclined conveyor 3 feeds the preforms 1 from the collection container 2 to the singulation device 4 essentially in increments, a metering device 8 in the form of a circulating conveyor belt is also arranged between the inclined conveyor 3 and the singulation device 4, by means of which the individual preforms 1 can be spaced apart from each other. However, such a design is insufficient, especially for higher machine outputs, in particular for outputs of more than 80,000 preforms 1 per hour.

[0040] Against this background, Fig. 2 shows a transport arrangement according to the invention in which the dosing device 8 is designed as a weighing system, wherein the dosing device 8 is configured to transfer a predefined number of preforms 1 to the singulation device 4 on a weight basis.

[0041] The exact operating principle is shown in a comparative illustration in Figures 3 and 4. The metering device 8 has a total of six metering chambers 9a, 9b, 9c, 10a, 10b, 10c, wherein the metering chambers 9a, 9b, 9c of a first row and the metering chambers 10a, 10b, 10c of a second row are arranged one behind the other in the transport direction T. Furthermore, the first row of metering chambers 9a, 9b, 9c is spaced apart from the second row of metering chambers 10a, 10b, 10c in the transverse direction Q, with all metering chambers 9a, 9b, 9c, 10a, 10b, 10c having a common discharge section 11, which is arranged above the conveying lane 7 and enables the feeding of the preforms 1 into the conveying lane 7.

[0042] Figure 3 illustrates that different numbers of preforms 1 are present in the individual dosing chambers 9a, 9b, 9c, 10a, 10b, 10c. A weighing unit 12 records the weight of the preforms 1 in each dosing chamber, and a control device (not shown) determines the number of preforms 1 based on the recorded weight. If a predefined number of containers are arranged in the respective dosing chambers 9a, 9b, 9c, 10a, 10b, 10c, the control device can release an actuating section through which the preforms 1 pass via the discharge section 11 into the conveying lane 7.

[0043] As shown in Fig. 3, the metering chamber 9b indicates that a predefined number of containers has been reached. In this example, there are a total of five preforms 1, with preferably between six and fourteen preforms 1 constituting the predefined number. Then, as shown in Fig. 4, an actuating section of the metering chamber 9b is moved to the open position, so that the containers 1 can be fed to the discharge section 11. In principle, it is also conceivable that several metering chambers 9a, 9b, 9c,

[0044] 10a, 10b, 10c will be released if the total number of preforms corresponds to the predefined number of containers. For example, according to Fig. 3, a combination of dosing chambers 10a, 10b could also be released, or a combination of dosing chambers 9a, 10c.

[0045] Reference symbol list

[0046] 1 preform

[0047] 2 collection containers, 3 inclined conveyors

[0048] 4. Single-person access device

[0049] 5 Air conveying section

[0050] 6 conveyor rollers

[0051] 7 Conveyor lane 8 Dosing device

[0052] 9, 10 dosing chambers

[0053] 11 Outlet section

[0054] 12 weighing units

[0055] Q transverse direction T transport path

[0056] D axis of rotation

Claims

Patent claims:

1. Transport arrangement for transporting containers with a singulation device (4) which has a conveying lane (7) formed from two conveying rollers (6) spaced apart from each other in a transverse direction (Q) and arranged to rotate in opposite directions and a metering device (8) upstream of the conveying lane (7), characterized in that the metering device (8) is configured to transfer a predefined number of containers to the singulation device (4) based on weight.

2. Transport arrangement according to claim 1, characterized in that the predefined number of containers is between 6 and 14, in particular between 8 and 12, containers.

3. Transport arrangement according to one of the preceding claims, characterized in that the metering device (8) has at least one metering chamber (9, 10) for receiving containers and wherein the metering chamber (9, 10) has an actuating section movable between an open and closed position.

4. Transport arrangement according to claim 2, characterized in that the metering device (8) has at least three, preferably at least four, particularly preferably at least five, metering chambers (9, 10).

5. Transport arrangement according to claim 3, characterized in that the metering chambers (9, 10) each have an actuating section which connects to a common outlet section (11).

6. Transport arrangement according to one of claims 2 to 5, characterized in that a control section is moved into the open position when the predefined number of containers in each dosing chamber (9, 10) is reached, or at least the control sections of at least two dosing chambers (9, 10) are moved into the open position when the predefined number of containers is reached together.

7. Transport arrangement according to any one of claims 2 to 6, characterized in that the dosing device (8) has a control device and a weighing unit (12) connected to the control device and assigned to the dosing chamber (9, 10), wherein the The control device is designed to determine the number of containers arranged in the dosing chamber (9, 10) based on the weight determined by the weighing unit (12) and to move the actuating section to an open position based on the determined number.

8. Transport arrangement according to one of the preceding claims, characterized in that the metering device has an inlet section which connects to the outlet of an inclined conveyor.

9. Transport arrangement according to one of the preceding claims, characterized in that the containers are preforms (1 ).

10. Transport arrangement according to one of the preceding claims, characterized in that the singulation device (4) has a container separation which is connected via a return device to the metering device (8), in particular to the feed section.

11. Forming system comprising a forming machine for the plastic forming of preforms (1) into beverage containers and a transport arrangement upstream of the forming machine according to one of the preceding claims.

12. Forming system according to claim 11, characterized in that the forming machine is a blow molding machine, in particular a stretch blow molding machine.

13. Method for operating a transport arrangement according to one of claims 1 to 10 and / or a forming system according to claim 11 or 12, wherein containers, in particular preforms, are fed to the metering device (8) and, based on weight, are transferred to the singulation device (4) after reaching a predefined number.

14. Method according to claim 13, wherein the containers are weighed and the number of containers is determined based on the weight.

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