Level reader device, level reader system, and package manufacturing machine equipped with a level reader system

Abstract

Disclosed herein is a level reader apparatus (60) for a packaging machine. The level reader apparatus (60) comprises a housing (62) extending in a longitudinal direction substantially parallel to a fill direction (44) of a tube of packaging material (24), and a plurality of sensors (64) distributed within the housing (62) along the longitudinal direction and configured to provide one or more sensor readings (65). The level reader apparatus (60) further comprises a processing unit (66) configured to determine a level (80) of liquid within the tube of packaging material (24) based on the one or more sensor readings (65).

Description

[Technical Field]

[0001] The present invention relates to a level reader device for package manufacturing machines. The present invention also relates to a level reader device and a package manufacturing machine including the level reader device. [Background Art]

[0002] When manufacturing packaging containers for liquid foods such as milk, mineral water, tea, juice, soup, and drinks, web-shaped laminated packaging materials are sometimes used. The packaging container is manufactured by initially sealing the web-shaped laminated packaging material in the longitudinal direction via heat sealing, ultrasonic sealing, or the like. Therefore, a seal strip can be attached to the end of the web-shaped laminated packaging material. Next, the laminated packaging material is formed into a tube shape, the opposite ends of the laminated packaging material are brought into contact and sealed in the longitudinal direction (vertical direction), so that the tube can be closed in the longitudinal direction.

[0003] A filling pipe is usually arranged inside the tube of packaging material, and the desired liquid content is discharged through the filling pipe. During continuous production, the amount of liquid inside the tube is kept relatively constant, so that a partially filled tube is maintained. The partially filled tube is transversely sealed at regular intervals, thereby forming a series of pillow-shaped preform containers. The preform container is formed into a predetermined shape and separated from the upstream tube, completing the manufacture of the packaging material container.

[0004] Precise control of the amount of liquid content in a tube is particularly important in sealing and molding operations for providing containers for packaging materials. When a tube is filled with too much liquid, the resistance to the clamping action of the lateral sealing jaws increases. This increased resistance can damage the packaging material container during the final molding and shaping of the container. Examples of damage that may result from increased resistance include cracking or breakage in the sealed portion of the packaging material. Furthermore, if the amount of liquid in the tube exceeds a certain level, there is a risk of overfilling. Overfilling can lead to leakage, potentially resulting in production stoppages or damage to related components. Since production stoppages are costly, reducing the risk of damage to packaging materials during the filling and molding of packaging containers is extremely important. Even if leakage does not occur, overfilling results in the undesirable waste of the filled food. Therefore, monitoring the liquid level in the packaging manufacturing machine is desirable.

[0005] In light of the above observations, there is a need for improved control of the liquid content level within the tube of the packaging material. Accordingly, the inventors have identified both the need and the advantages of robustly and accurately measuring the liquid content level. [Overview of the project] [Problems that the invention aims to solve]

[0006] The object of the present invention is to solve, eliminate, mitigate, reduce or reduce at least some of the problems and drawbacks mentioned above. [Means for solving the problem]

[0007] This disclosure proposes solutions to the above-mentioned problems. The proposed solutions describe level reader devices, level reader systems, and package manufacturing machines.

[0008] In a first embodiment, a level reader device for a packaging manufacturing machine is provided. The level reader device comprises a housing extending in a longitudinal direction substantially parallel to the filling direction of a tube of packaging material; a plurality of sensors distributed within the housing along the longitudinal direction and configured to provide one or more sensor readings; and a processing unit configured to determine the level of liquid in the tube of packaging material based on one or more sensor readings.

[0009] The advantage of the present invention lies in the fact that, due to the very high density of sensors, the level reader device can provide extremely accurate liquid level signals. Furthermore, since the overall length of the level reader device is substantially larger than that known in the art, maintaining liquid level control can be done in a larger space. Consequently, the package manufacturing machine becomes more robust and versatile for different package sizes, and the risk of overfilling the machine with liquid (and thus stopping machine production) is greatly reduced. The topology of multiple sensors further simplifies the installation of the level reader device and related components in the package manufacturing machine. In addition, the improved sensitivity of the multiple sensors in the level reader device allows for compatibility with various related magnetic devices that cannot generate strong magnetic fields. As a result, the risk of misinterpretation can be minimized.

[0010] According to one embodiment, a plurality of sensors are configured to simultaneously provide one or more sensor readings that represent defined values ​​separated from zero, wherein one of the sensor readings represents a higher value than the other sensor readings.

[0011] According to one embodiment, the processing unit is configured to determine the level of liquid in the tube of the packaging material from one sensor reading that shows a higher value than other sensor readings.

[0012] According to one embodiment, one of the sensor readings, one of which is lower than the other sensor readings, is configured to determine the liquid level in the tube of the packaging material from the average value of the sensor reading that is higher than the other sensor readings and the sensor reading that is lower than the other sensor readings.

[0013] According to one embodiment, the processing unit is configured to determine the level of liquid in a tube of packaging material from a moving average of a predetermined number of previously provided sensor readings.

[0014] According to one embodiment, the processing unit is configured to determine the liquid level in the tube of the packaging material by selecting one of the readings of the one sensor that shows a higher value than the readings of the other sensors, the average value, or the moving average.

[0015] According to one embodiment, the number of sensors is in the range of 15 to 45, preferably in the range of 20 to 40, and most preferably in the range of 25 to 35.

[0016] According to one embodiment, each of the multiple sensors is a magnetoresistive sensor.

[0017] According to one embodiment, the magnetoresistance sensitivity of each sensor is in the range of 5 to 15 G, preferably in the range of 7 to 11 G.

[0018] According to one embodiment, the magnetoresistance sensitivity of each sensor is in the range of 10 to 25 G, preferably in the range of 14 to 20 G.

[0019] In a second embodiment, a level reader system is provided for determining the level of liquid in a tube of packaging material. The level reader system comprises a magnetic float and a level reader device according to any of the first embodiment and related embodiments.

[0020] According to one embodiment, the magnetic float comprises a cylinder and a ring-shaped holder disposed inside the cylinder, the ring-shaped holder comprising a plurality of magnets dispersed around the holder.

[0021] According to one embodiment, the longitudinal extension of the housing is substantially greater than the vertical extension of the ring-shaped holder.

[0022] In a third embodiment, a package manufacturing machine is provided. The package manufacturing machine comprises a level reader system according to either the second embodiment or an embodiment related thereto.

[0023] Where used herein, the term “comprises / comprising” is used to specify the presence of a described feature, integer, step, or component, but it should be emphasized that it does not exclude the presence or addition of one or more other features, integers, steps, components, or groups thereof. All terms used in the claims shall be construed in accordance with their ordinary meaning in the art unless expressly defined otherwise herein. All references to a / an / the “element, device, component, means, step, etc.” shall be openly construed as referring to at least one example of an element, device, component, means, step, etc., unless expressly stated otherwise. The steps of any method disclosed herein do not need to be performed in the exact order disclosed unless expressly stated otherwise.

[0024] The above will become clear from the following more detailed description of the exemplary embodiments shown in the attached drawings, where the same reference letters refer to the same parts across different figures. The drawings are not necessarily to scale and are primarily intended to illustrate the exemplary embodiments. [Brief explanation of the drawing]

[0025] [Figure 1] This is a schematic diagram showing one embodiment of a package manufacturing apparatus. [Figure 2a] It is a schematic block diagram of one embodiment of a level reader system. [Figure 2b] It is a schematic diagram of a level reader system according to one embodiment. [Figure 3a] It is a schematic block diagram showing one embodiment of a level reader system. [Figure 3b] It is a schematic diagram of a level reader system according to one embodiment. [Figure 4a] It is a perspective view of a level reader system according to an embodiment. [Figure 4b] It is a cross-sectional view showing an embodiment of a level reader device. [Figure 4c] It is a cross-sectional view showing an embodiment of a level reader device. MODE FOR CARRYING OUT THE INVENTION

[0026] Next, embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and should not be construed as limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. The terminology used in the detailed description of the particular embodiments illustrated in the accompanying drawings is not intended to limit the present invention. In the drawings, the same reference numerals refer to the same elements.

[0027] Referring to Figure 1, an illustrated package manufacturing machine 10 according to one embodiment is shown. The illustrated package manufacturing machine 10 can be used in the food packaging industry to produce packaged containers 30 filled with liquid foods such as milk, mineral water, tea, juice, soup, and drinks. The production of the packaged containers 30 involves several steps, processes, or techniques, some of which are shown in Figure 1. The illustrative images merely illustrate one possible embodiment of the package manufacturing machine 10 as disclosed herein and should not be construed as limiting the scope of this disclosure. The package manufacturing machine 10 may include any number of additional or fewer steps, processes, or techniques, provided that the inventive aspects of this disclosure are possible.

[0028] In Figure 1, the web of the packaging material 20 is supplied, for example, on a reel 22 and continuously fed through the packaging machine 10, where it passes through several different stations during operation. Figure 1 specifically shows the sterile chamber 15, the filling station 40, and the sealing and molding station 50, but other related stations are also feasible.

[0029] The web of the packaging material enters the sterile chamber 15 and passes through a sterilization unit 150 in the form of one or more electron beam emitters 152. After being exposed to electron beam irradiation, the web of the packaging material 20 exits the sterile chamber 15. The sterilization unit 150 does not necessarily have to rely on electron beam irradiation, as it can use other sterilization techniques such as H2O2.

[0030] In the filling station 40, the web of the packaging material 20 is formed on a tube 24 of the packaging material, hereinafter simply referred to as the “tube”. The tube 24 is filled with a desired liquid content, preferably a liquid food, via a filling pipe 42. The filling station 40 includes a level reader system 200 configured to monitor the amount of liquid content in the tube 24, which will be described in more detail with reference to the remaining figures of this disclosure.

[0031] Downstream of the filling station 40 is a sealing and molding section 50. The sealing and molding section 50 is configured to apply a lateral seal to the tube 24, cut the leading portion of the tube 24 from the upstream tube 24 at the lateral seal location, and mold the separated packaging container 30 into a desired shape. Multiple sealing jaws (not shown) may be provided, which are configured to provide a lateral seal to the tube 24 by engaging with the tube 24. These lateral seals can be formed, for example, by induction heating, which means that the sealing jaws must engage with the tube 24 for a certain period of time in order to form a high-quality lateral seal. The tube 24 is then cut along the lateral seal into the packaging container 30 by a cutting means.

[0032] The processes performed in the sealing and molding unit 50 typically affect the liquid level 80 within the tube 24. For example, each time the tube 24 is given its lateral seal, the contact caused by applying the seal jaw reduces the total volume of space within the tube 24. Consequently, the liquid level 80 within the tube 24 will rise. The volume within the tube 24 is also affected by the shape of the tube 24, and since the sealing and molding unit 50 typically shapes the tube 24 from a circular cross-section to a rectangular cross-section, the area enclosed by the tube 24 decreases. As can be understood from the above, repeated operation of the sealing and molding unit 50 results in fluctuations in the liquid level 80 within the tube 24. Furthermore, for example, the energy generated by giving the tube 24 a lateral seal using induction heating can affect the kinetic energy, and as a result, may also affect the liquid level 80 within the tube 24. There are countless other examples of external influences, production changes, material selections, etc., and because various situations can occur, it is difficult to accurately determine how much the liquid level 80 within the packaging material will change. Those skilled in the art can realize additional such situations.

[0033] In a high-performance packaging manufacturing machine 10 capable of producing a large number of packaging containers 30 per second, controlling the liquid level 80 is particularly difficult. If the liquid level 80 in the tube 24 is not precisely controlled, problems similar to those presented in the prior art may arise. Therefore, it is of paramount importance that the level reader system 200 be able to read the liquid level 80 in the tube 24 with extreme accuracy.

[0034] Next, referring to Figures 2a and 2b, one embodiment of the level leader system 200 is shown.

[0035] In a preferred embodiment of the present invention, the level reader system 200 comprises a level reader device 60 and a magnetic float 70 (see also Figure 1). In Figure 2a, the squares with dashed lines indicate features of a more arbitrary nature, but nevertheless represent a preferred embodiment of the present invention. Those skilled in the art can realize additional embodiments of these features to enable precise monitoring of the liquid level 80 in the tube 24.

[0036] The magnetic float 70 may be positioned inside or within the tube 24 so that at least a portion of the magnetic float 70 can float on the surface of the liquid in the tube 24. This is visualized in Figure 2b. At least one portion of the magnetic float 70 is capable of floating in both high-density and low-density liquids. The magnetic float 70 may comprise one or more buoyancy materials. In different embodiments of the present invention, the magnetic float 70 may comprise different buoyancy materials, which can be interchanged as needed. Desirable properties of the buoyancy material may include excellent buoyancy, a high strength-to-weight ratio, a large operating temperature range, high pressure resistance, etc.

[0037] The magnetic float 70 is not limited to having a specific shape, form, or dimensions, as long as it can fit within the tube 24 and perform the intended function described below.

[0038] As shown in Figures 2a-b, the magnetic float 70 may comprise a cylinder 72 and a ring-shaped holder 74 positioned within the cylinder 72. The cylinder 72 is preferably positioned on the outer circumference of the filling pipe 42, but other arrangements are also possible. The filling pipe 42 is fixedly positioned within the tube 24 and is configured such that the filling direction 44 is substantially perpendicular to the axis perpendicular to the ground. Therefore, the cylinder 72 is configured to be movable along the filling pipe 42 in the filling direction 44. The magnetic float 70 floats on the liquid in the tube 24, thereby allowing the cylinder 72 to move due to the upward or downward movement of the magnetic float 70 caused by the level 80 of the liquid in the tube 24. The magnetic float 70 may be positioned to rotate freely around the filling pipe 42. This is particularly beneficial because it minimizes or eliminates the risk that the level reader device 60 may not be able to pick up magnetic signals or magnetic fields such as those generated by the magnetic float 70.

[0039] As shown in Figures 2a and 2b, the cylinder 72 may include a ring-shaped holder 74. In one embodiment, the ring-shaped holder 74 is located inside the cylinder 72. The ring-shaped holder 74 may include a plurality of magnets 75 that are dispersed, arranged, or held around the holder 74. Figure 2b shows in detail how the plurality of magnets 75 are distributed around the ring-shaped holder 74. In this example, a total of 10 magnets are arranged around the holder 74. The number of magnets in the magnetic float 70 may vary depending on, for example, the dimensions, material, or other characteristics of the magnetic float 70, the filling pipe 42, and / or the magnetic reader 60.

[0040] In an alternative embodiment, the multiple magnets 75 may be arranged on either the magnetic float 70 or the cylinder 72 without requiring the assistance of the ring-shaped holder 74 and / or the cylinder 72.

[0041] As the magnetic float 70 moves along the filling direction 44 and, in some cases, rotates around the filling pipe 42, the multiple magnets 75 are configured to continuously generate magnetic signals or magnetic fields. A level reader device 60 is configured to read these signals to determine the current level 80 of the liquid in the tube 24.

[0042] Next, we will refer to Figures 3a and 3b, which show a level reader system 200 according to one embodiment. The level reader device 60 will be described in more detail with reference to these figures. The level reader device 60 comprises a housing 62, a plurality of sensors 64, and a processing device 66.

[0043] In different embodiments of the level reader device 60, the housing 62 is shaped, sized, molded and / or dimensional in any preferred manner. Preferably in this regard, the housing 62 is positioned in the package manufacturing machine 10 and adapted to accommodate the components of the level reader device 60. As shown in Figure 3b, the housing 62 extends longitudinally, substantially parallel to the filling direction 44 of the tube 24. The housing 62 may have an elongated shape that extends longitudinally. Preferably, the housing 62 is positioned close to the tube 24, i.e., the magnetic float 70, so that the level reader device 60 can read the magnetic signal or magnetic field generated from the magnetic float 70, even when the tube 24 is positioned between the level reader device 60 and the magnetic float 70.

[0044] Multiple sensors 64 are distributed along the longitudinal direction within the housing 62 and are configured to provide one or more sensor readings 65. Preferably, the multiple sensors 62 are distributed along the extending edge of the housing 62 facing the magnetic float 70 so that one or more sensor readings 65 can be provided more accurately. Alternatively, the multiple sensors 64 may be distributed anywhere within the housing 62, given that the sensor readings 65 can be provided accurately.

[0045] The multiple sensors 64 may be any number of sensors that can fit within the housing 62. In one embodiment, the number of multiple sensors 64 is 15 to 45. In a more preferred embodiment, the number of multiple sensors 64 is 20 to 40. In the most preferred embodiment, the number of multiple sensors 64 is 25 to 35. The multiple sensors are generally distributed along a specific length corresponding to the length of the side surface extending in the longitudinal direction of the housing. In one embodiment, the length is between 10 and 35 cm. In a more preferred embodiment, the length is between 15 and 30 cm. In the most preferred embodiment, the length is between 20 and 25 cm.

[0046] Multiple sensors 64 may be magnetoresistive sensors, which are commonly known in the art. Magnetoresistive sensors are ultra-sensitive devices designed as durable and reliable speed or position sensors for small magnetic fields in power applications. The power supply voltage range for such applications may be in the range of 3Vdc to 24Vdc, and is typically around 12Vdc. The temperature range for magnetoresistive sensors may be -40°C to 85°C. Because magnetoresistive sensors do not require identification of magnet polarity, the installation process is simplified and system costs can be reduced. Advantages of magnetoresistive sensors include, for example, durability and reliability due to their magnetic solid state, non-contact and matte design, and cost-effectiveness and flexibility due to their ultra-high sensitivity.

[0047] The magnetoresistance sensitivities of the multiple sensors 64 may be typical values ​​for such magnetoresistance sensors. In one embodiment, the magnetoresistance sensitivities are in the range of 5G to 25G. The magnetoresistance sensors may be based on two different types of sensors. Of these, the first type has a magnetoresistance sensitivities in the range of 7G to 11G, where 7G is the typical operating sensitivity and 11G is the maximum operating sensitivity. The second type has a magnetoresistance sensitivities in the range of 14G to 20G, where 14G is the typical operating sensitivity and 11G is the maximum operating sensitivity. One or a combination of these two types may be used for the magnetic float 70. By providing a magnetoresistance sensor with higher magnetoresistance sensitivity, according to this description, the level reader device 60 can be positioned further away from the magnetic float 70 than conventionally, thereby simplifying the installation and operation processes.

[0048] The processing unit 66 may be configured as a single unit or as a group of controllers collectively configured to perform the operation of the processing unit 66. The processing unit 66 may include, but is not limited to, a microcontroller, a processor (e.g., PLC, CPU, DSP), FPGA, ASIC, or any other suitable digital and / or analog circuitry capable of performing the intended function, and may be implemented with any known controller technology. The processing unit 66 may include memory. The memory of the processing unit 66 may include, but is not limited to, ROM, RAM, SRAM, DRAM, CMOS, FLASH, DDR, SDRAM, or other memory technology, and may be implemented with any known memory technology. In some embodiments, the memory may be integrated with the processing unit 66 or built into the processing unit 66.

[0049] The processing unit 66 is configured to receive, analyze, and determine a decision based on one or more signal readings 65 provided from multiple sensors 64. The decision relates to determining the level 80 of the liquid in the tube 24.

[0050] In one embodiment, the processing unit 66 is located within the housing 62. Alternatively, the processing unit 66 is located as an external unit that communicates with the level reader device 60 by wire and / or wirelessly. In either of these two embodiments, the processing unit 66 is located so that a determination regarding the liquid level 80 in the tube 24 can be made in a very short time. In a preferred embodiment, the time required to provide a signal reading 65, analyze the signal reading 65, and accurately determine the liquid level 80 in the tube 24 is less than 1 ms.

[0051] If the processing unit 66 is configured as an external unit that communicates wirelessly with the level reader device 60, the level reader device 60 may further include any communication means known in the art to enable such communication. Such communication means may be based on short-range communication technologies such as WiFi or Bluetooth.

[0052] Regardless of where the processing unit 66 is located, the determination may be used to control the overall operation of the package manufacturing machine 10, particularly the operation of the filling pipe 42. For example, the determination may be used to control the discharge flow of liquid from the filling pipe 42, the operating speed of the package manufacturing machine 10, or any similar control operations that can be achieved by those skilled in the art. Such operations are preferably controlled automatically.

[0053] Figure 3b shows one embodiment of a level reader device 60. This particular level reader device 60 includes 15 sensors, each individually configured to provide a sensor reading 65. Since the multiple sensors 64 can operate independently, one or more sensor readings 65 may be provided simultaneously from different sensors 64. A sensor reading 65 indicates a defined value separated from zero. Here, “defined” means a correctly read signal indicating a value, i.e., not a misreading. Thus, a sensor reading 65 indicates that a magnetic object, such as a magnetic float 70, is close enough to one of the multiple sensors 64 to identify a magnetic signal. Since one or more sensor readings 65 can be provided simultaneously, and the individual sensors of the multiple sensors 64 are positioned at different locations along the side of the housing 62 and provide readings 65 for the same magnetic object, the values ​​are typically different from one another, for example, depending on the actual distance between a particular sensor 64 and the magnetic float 70.

[0054] In the specific example shown in Figure 3b, a total of nine sensor readings 65 are read simultaneously, each indicating a defined value separated from zero. For simplicity, the values ​​are shown in the figure as positive integer values ​​from "1" to "4". However, in the case of an actual level reader device 60, these values ​​may be assumed to be any appropriate values. As can be seen from the figure, sensors 64 closer to the magnetic float 70 provide sensor readings 65 that indicate higher values ​​than sensors 64 further away from the magnetic float 70.

[0055] As shown in Figure 3b, one of the one or more sensor readings 65h shows a higher value than the other identified readings. In the illustrative figure, this value is "4". If one sensor reading shows exactly the same value as the other sensor readings, either or both of these two values ​​may be identified as sensor reading 65h as showing a higher value than the other readings. Therefore, the processing unit 66 may be configured to determine the liquid level 80 in the tube 24 from the one sensor reading 65h that shows a higher value than the other sensor readings.

[0056] In an alternative embodiment, one of the one or more sensor readings 65l shows a lower value than the other sensor readings. In Figure 3b, this value is "1", which can be seen in the reading 65 that is determined to be provided by the two separate sensors 64 furthest from the magnetic float 70. The processing unit 66 may be configured to determine the liquid level 80 in the tube 24 from the average value 65a of the sensor reading 65h that shows a higher value than the other sensor readings and the sensor reading 65l that shows a lower value than the other sensor readings.

[0057] In yet another embodiment, the processing unit 66 is configured to determine the liquid level 80 in the tube 24 from a moving average 65ma of a predetermined number of previously provided sensor readings 65. In one embodiment, the predetermined number is the total number of all sensors 64 combined. In another embodiment, the predetermined number is the number for each individual sensor 64. Typically, the number of previously provided sensor readings may be eight, but the number can also be fewer, more, or change during operation. Determining the liquid level 80 in the tube 24 from a moving average 65ma is particularly useful in cases of abrupt drops or increases in the liquid level 80, or to handle erroneous readings 65 provided by, for example, a defective sensor 64.

[0058] In one embodiment, the processing unit 66 may be configured to determine the liquid level 80 in the tube 24 by selecting one of the following: a sensor reading 65h that shows a higher value than other sensor readings, an average value 65a, or a moving average 65ma. This selection may be controlled automatically by the processing unit 66 or manually by an operator or technician. The selection may be based on a variety of different factors, such as what liquid, components, materials, or operating settings are used. The processing unit 66 may be configured to intelligently generate a decision based on the sensor reading 65, for example, by analyzing previously acquired data about the current operating settings. Such an intelligent decision may be generated by a self-learning algorithm that implements known supervised and / or unsupervised learning algorithms, such as exemplary regression algorithms, decision trees, K-means, K-nearest neighbors, neural networks, support vector machines, or principal component analysis.

[0059] Figures 4a to 4c are schematic diagrams of a level reader device 60 in accordance with the present disclosure.

[0060] In Figure 4a, the level reader device 60 can be seen in its arrangement with the magnetic float 70, i.e., in the level reader system 200. In the preferred embodiment shown in Figure 4a, the longitudinal extension of the level reader device 60 is substantially greater than the vertical extension of the magnetic float 70. In particular, the longitudinal extension of the housing 62 is substantially greater than the vertical extension of the ring-shaped holder 74. This allows for a very robust filling system, as the ring-shaped holder 74, which holds multiple magnets 75, can be correctly identified by the level reader device 60 even when it moves a distance several times longer than its own vertical extension. The length ratio between the housing 62 and the vertical extension of the ring-shaped holder 74 may be similar to the length ratio depicted in Figure 4a. Other length ratios may also be implemented.

[0061] Figure 4a further illustrates a fixing means 68 adapted to secure the level reader device 60 to other components of the packaging machine 10. In this example, the fixing means 68 is provided as an arm fixedly attached to the packaging machine 10. In other embodiments, the fixing means 68 may be any structure that is suitably attached to the packaging machine using one or a combination of screws, bolts and / or adhesive materials. Since the level reader device 60 is securely fixed and kept stationary during operation, its position can be calibrated and set, for example, in relation to the downstream sealing jaws, and as described above, it is possible to translate the actual sensors to the height above the sealing jaws by associating the reading indication values ​​65 with the respective sensors 64. Thus, the monitored level of the product in the tube 24 can be easily translated to the tube filling height in centimeters or millimeters.

[0062] Figure 4b is a schematic diagram of a level reader device 60 according to a preferred embodiment, and Figure 4c is an enlarged cross-sectional view of Figure 4b. The exemplary image generally shows how the housing 62, the multiple sensors 64, and the processing unit 66 may be arranged within the level reader device 60.

[0063] The present invention has been described above, primarily with reference to several embodiments. However, as will be readily apparent to those skilled in the art, other embodiments not disclosed above are also possible within the scope of the present invention as defined by the appended claims.

Claims

1. A level reader system (200) for determining the liquid level (80) inside a tube (24) of packaging material, wherein the level reader system (200) comprises a magnetic float (70) and a level reader device (60), The level leader device (60) is A housing (62) extending in a longitudinal direction substantially parallel to the filling direction (44) of the tube (24), A plurality of sensors (64) are distributed within the housing (62) along the longitudinal direction and are configured to provide one or more sensor readings (65), A processing unit (66) is configured to determine the liquid level (80) in the tube (24) based on the readings (65) of one or more sensors, and Equipped with, The magnetic float (70) comprises a cylinder (72) and a ring-shaped holder (74) disposed within the cylinder (72), the ring-shaped holder (74) comprises a plurality of magnets (75) dispersed around the ring-shaped holder (74). Level leader system (200).

2. The level reader system (200) according to claim 1, wherein the plurality of sensors (64) are configured to provide one or more sensor readings (65) indicating a defined value separated from zero, and one of the sensor readings (65h) indicates a value higher than the other sensor readings.

3. The level reader system (200) according to claim 2, wherein the processing unit (66) is configured to determine the level (80) of the liquid in the tube (24) from one sensor reading (65h) that is higher than the other sensor readings.

4. One of the one or more sensor readings (65) (65l) shows a lower value than the other sensor readings. The level reader system (200) according to claim 2 or 3, wherein the processing unit (66) is configured to determine the level (80) of the liquid in the tube (24) from the average value (65a) of the sensor reading (65h) which is higher than the other sensor readings and the sensor reading (65l) which is lower than the other sensor readings.

5. The level reader system (200) according to any one of claims 2 to 4, wherein the processing unit (66) is configured to determine the level (80) of the liquid in the tube (24) from a moving average (65ma) of a predetermined number of previously provided sensor readings (65).

6. The processing unit (66) controls the liquid level (80) in the tube (24), The one sensor reading (65h) that shows a higher value than the other sensor readings, The average value (65a) of the one sensor reading (65h) and the sensor reading (65l) that shows a lower value than the other sensor readings, A moving average (65ma) of a predetermined number of sensor readings (65) previously provided. A level leader system (200) according to any one of claims 3 to 5, configured to select and determine one of the following.

7. The level reader system (200) according to any one of claims 1 to 6, wherein the number of sensors (64) is 15 to 45 sensors.

8. The level reader system (200) according to any one of claims 1 to 7, wherein the plurality of sensors (64) are distributed along a length of 10 to 35 cm.

9. The level reader system (200) according to any one of claims 1 to 8, wherein the plurality of sensors (64) are magnetoresistive sensors.

10. The level reader system (200) according to claim 9, wherein the magnetoresistance sensitivity of the magnetoresistance sensor is in the range of 5 gauss to 15 gauss.

11. The level reader system (200) according to claim 9, wherein the magnetoresistive sensitivity of the magnetoresistive sensor is in the range of 10 gauss to 25 gauss.

12. The plurality of sensors (64) can operate individually, and the one or more sensor readings (65) are provided simultaneously from different sensors (64) of the plurality of sensors (64). A level leader system (200) according to any one of claims 1 to 11.

13. The level leader system (200) according to claim 1, wherein the length of the housing (62) along the longitudinal direction is greater than the length of the ring-shaped holder (74) along the longitudinal direction.

14. A package manufacturing machine (10) comprising a level reader system (200) according to any one of claims 1 to 13.

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