EP4291343A1

EP4291343A1 - Folding shaft device for a closer, and method for fastening a can lid to a can body

Info

Publication number: EP4291343A1
Application number: EP21705462.6A
Authority: EP
Inventors: Marco Siegrist
Original assignee: Ferrum Packaging AG
Current assignee: Ferrum Packaging AG
Priority date: 2021-02-11
Filing date: 2021-02-11
Publication date: 2023-12-20
Also published as: US20240082903A1; WO2022171279A1; CA3210907A1

Abstract

The invention relates to a folding shaft device for a closer (1000) for fastening a can lid (101) to a can body (100), comprising a folding shaft (3, 3A) rotatable about a folding axis (X); a folding means (2, 10) arranged at an end of the folding shaft (3, 3A); and a sensor (4, 40, 41) for monitoring a folding process when fastening the can lid (101) to the can body (100). The sensor (4, 40, 41) is here arranged to the folding shaft (3, 3A) in such a way that the folding process (3, 3A) can be monitored by the sensor (4, 40, 41) on the basis of a measurement of a deflection of the folding shaft (3, 3A) relative to the folding axis (X) and/or of a measurement of a torsion of the folding shaft (3, 3A).

Description

SEAM SHAFT DEVICE FOR A SEAMER AND METHOD OF ATTACHING A CAN LID TO A CAN BODY

The invention relates to a folding shaft device for a seamer and a sensor for the folding shaft device according to the invention. The invention further relates to a seamer and a seaming station with a seaming shaft device according to the invention, as well as a method for fastening a can end to a can body.

When filling beverage cans or food cans, cans pass through a can seamer after being filled with a beverage or food, with the filled can bodies entering via a feed path and can lids (including lids) entering via a further feed path. The can seamer usually has a plurality of stations of the same type arranged in the form of a carousel (hereinafter also referred to as carousel), in each of which a can body is closed with a can end. The can lids are guided onto the can body and held on the can body with an ejection head arranged on a seaming head. This holding by the ejection head occurs only while the can is rising (combination of can body and can lid). The can is then clamped in the seaming head for sealing. In the can seamer, the can body with the can end is seamed at the edge using a seaming roller and thus sealed. As a rule, the can body with the can end is additionally rotated around its own axis of symmetry by the seaming head. The folding rollers and folding heads are arranged on a respective folding shaft for rotation. A generic can seamer is described in DE 749636 and DE4234115 A1. The can seamer comprises a clamping device for receiving a can to be seamed. In the operating state, the can to be sealed is placed in the clamping device and secured by it in the axial direction and radially at an upper end (by the seaming head). A can lid is also centered over the can opening of the can body to be closed. In the region of the can opening, the can body has a circumferential can flange and the can lid has a circumferential can lid flange. To close the can opening with the can end, the can seamer additionally comprises two seaming rollers, each mounted rotatably about an axis, which press the can flange and the can end flange together by means of a force that acts essentially radially, with the pressing taking place by continuous rolling in the circumferential direction of the can opening.

In the prior art, units consisting of a seaming head and, as a rule, two seaming rollers are arranged on a circumference of the carousel. The sealer usually includes a large number of these units. As the carousel rotates, the can lid is placed on the can body, the filled can body is lifted with the lid against the seaming head and sealed. Thereafter, the sealed can is lowered again and removed from the seaming head.

Errors can occur during the entire can seaming process due to adjustments, worn seaming devices or defects on the can. However, a high seam quality of the filled cans has a very high priority. A "bad fold" can include defects such as scratches on the can end, a macro-leakage, a micro-leakage or cut can parts in the product. These errors can not only result in defective products, but also lead to machine failure.

In order to detect such errors, information is collected and analyzed in the prior art by monitoring the folding process in order to prevent machine downtime or excessive rejects.

A device for monitoring a double seam closing process is known from WO 2006/125680 A1. The device comprises a lifting mechanism for lifting the can body, a closing tool for a first and a second operation. The closing process can be monitored by sensors for detecting a strain and/or a force that is exerted on a flexing mechanism for the can, by analyzing a change in the basic load and shifts in the measured force. For this purpose, the sensors are mounted on a part of a flex cam of the flex mechanism.

However, the devices known in the prior art can only detect coarser defects such as so-called "skidders", which lead in particular to macro-leakage. In addition, the prior art methods only analyze the seaming process during the last can rotation.

The object of the invention is therefore to provide a folding shaft device for a closer and a folding station, in particular a method, which avoids the disadvantageous effects known from the prior art. In particular, a folding shaft device is to be provided which enables the folding process to be monitored more precisely. In particular, hemming forces should be recorded continuously and in real time during the hemming process be able. In particular, it should also be possible to analyze the entire folding process with all folding operations.

The object is achieved by a folding shaft device according to the invention, a seamer and a folding station with the folding shaft device according to the invention and by the method according to the invention.

According to the invention, a seaming shaft device for a seamer for fastening a can end to a can body is provided, comprising a seaming shaft which can be rotated about a seaming axis, a seaming means arranged at one end of the seaming shaft, and a sensor for monitoring a seaming process when the can end is fastened to the can body (or in the case of the Closing the can lid with the can body), suggested. The folding shaft device according to the invention is characterized in that the sensor is arranged on the folding shaft in such a way that the folding process can be monitored by the sensor by measuring a deflection of the folding shaft relative to the folding axis and/or by measuring a torsion of the folding shaft.

During the folding process, the folding shaft is compressed and bent. The fold means is pushed away from the fold by the acting forces, resulting in a compression / bending of the fold shaft.

These forces can be detected by the sensor arranged on the folding shaft according to the invention as a deflection of the folding shaft relative to the folding axis or as torsion of the folding shaft. Errors during closure can be detected through deviations in compression and bending or the measured forces and consequently through deviations in deflection and / or torsion (defects usually have a larger deflection / torsion because the seaming means is pushed further away from the seam) . Torsion is the rotation of the fold shaft perpendicular to the fold axis. To measure the torsion, the sensor is preferably arranged in the circumferential direction of the folding shaft or the folding means. To measure the deflection, the sensor is preferably arranged along the folding shaft.

Thus, compared to WO 2006/125680 A1 and the other devices of the prior art, a better detection of errors is made possible, since measurements are taken directly on the folding shaft and not indirectly on a curve which is only involved in the folding process over several parts and bundles . The delays, damping and translations between machine parts that occur in this way can consequently be avoided by the device according to the invention. In addition, not only one end of a last hemming operation is considered, but the whole hemming process can be analyzed.

With the invention, folding forces can thus be detected in real time, which can be done in particular by measuring the force and/or strain on the folding shaft. Fold defects (such as «skidders», something jammed in the fold, missing lid, ...) lead to a «conspicuous» force curve and/or strain curve during folding and can be detected on the basis of this. In addition, not only fold defects can be monitored, but in particular wear and tear of the fold means can also be monitored (e.g. via a force/compression decreasing over time and thus deflection).

In an embodiment of the invention, the sensor for measuring the deflection and/or the torsion of the folding shaft can be arranged on a casing of the folding shaft. In addition, the sensor can be arranged on an inner lateral surface of the folding shaft and/or on an outer lateral surface of the folding shaft. If the sensor is arranged on the outer lateral surface, in particular on the outer lateral surface and thus on the surface of the folding shaft device, the deflection and/or the torsion can a surface expansion of the folding shaft can be determined. In addition, the sensor can be arranged on the folding means, so that the sensor is arranged on the folding shaft via the folding means. The sensor can also be arranged in the folding means or on the folding means (eg printed on the folding means).

The folding means is preferably arranged detachably at one end of the folding shaft, i.e. it can be attached to the folding shaft via a fastening mechanism and can thus be exchanged (e.g. for a tool change).

The seaming shaft can be designed as a seaming head shaft and the seaming means as a seaming head for fixing the can end on the can body. The fold axis is then the axis about which the fold head shaft or the fold head rotate in the operating state.

Alternatively or additionally, the seaming shaft can be designed as a seaming roller shaft and the seaming means can be designed as a seaming roller for seaming the can end onto the can body. The folding axis is then (alternatively or additionally) the axis about which the folding roller shaft or the folding roller rotates in the operating state.

In practice, the fold shaft device according to the invention can comprise an ejector device with an ejector rod, a slide profile and an ejector head, the ejector rod being movably arranged in the fold head shaft and the ejector head being arranged at a second end of the ejector rod in such a way that the ejector head can be moved along the slide profile is arranged between the seaming head shaft and the sliding profile. Such ejection devices with a folding cam are already known from the prior art. The sensor is particularly preferably a force sensor and/or a strain sensor, so that the deflection and/or the torsion of the folding shaft can be determined via a force measurement and/or a strain measurement on the folding shaft (and thus as a force curve and/or a strain curve). In this case, the sensor can be a strain gauge and/or a piezo force sensor. In addition, such sensors can be applied directly by printing nanoinks.

The strain gauge is suitable for detecting expanding and compressing deformations of the folding shaft. The strain gauge changes its electrical resistance even with small deformations and can thus record the deflection or torsion of the folding shaft. In principle, the strain gauge can be arranged on the surface of the folding shaft (e.g. with special adhesive). The strain gauge can be, for example, a foil, wire, and semiconductor strain gauge as well as a multiple strain gauge.

The piezo force sensor comprises a piezoelectric crystal (such as

Quartz). If a force acts on the piezoelectric crystal, this results in a charge change. The charge is proportional to the force acting on it. The charge is converted into a volt signal via a charge amplifier, via which the deflection and/or torsion of the folding shaft, in particular as an expansion curve or force curve, can be recorded.

Of course, other force and strain sensors or other sensor types such as distance sensors can also be used to detect the deflection and/or torsion of the folding shaft.

The sensor can also include a first sensor, a second sensor, and a third sensor. Here, the first sensor, the second sensor and the third sensor at different points along a Be arranged on the circumference of the folding shaft and also, in particular, be arranged at a height of the folding axis. They can be arranged at a uniform distance from one another, in particular at a distance of 120° from one another. In principle, any number of sensors can be used, which are preferably distributed evenly along the circumference of the folding shaft.

In a particularly preferred embodiment, the seaming head shaft comprises three strain gauges as sensors, which are attached at a distance of 120° from one another along the circumference of the seaming head shaft at the same height. However, more sensors, for example four or five sensors, can be used. In this way, a failure of a sensor can be compensated for, or measurement results from a sensor can be checked.

As a result, the elongation can be measured as a function of the force very close to "the place of action", a force profile can be measured over the entire hemming process and force can be recorded in three spatial directions.

According to the invention, a seaming station with a seaming shaft device according to the invention is also proposed, the seaming station comprising a lifting element and the can body with the can end being arranged as the first seaming means during the seaming process between the lifting element and the seaming head.

The seaming station preferably further comprises as seaming means a first seaming roller and in particular a second seaming roller for fastening the can end to the can body.

According to the invention, a closer, comprising a carousel with a large number of folding shaft devices according to the invention (or one Variety inventive folding stations) proposed. The seamer is therefore preferably a can seamer. The seamer according to the invention can further comprise a first feed for can bodies, in particular can bodies filled with a product, to the carousel and a second feed for can ends to the carousel.

In addition, the seamer may include an outlet for seamed cans from the carousel.

The can seamer (or the seaming shaft device) preferably comprises one or more seaming rollers (as known from the prior art) for seaming the can. In the operating state, the seaming rollers are brought into contact with their respective seaming profile with the can end flange of the can end and the can end flange of the can body. By rotating the can, the seaming roller is then rotated in the circumferential direction of the can, with the can flange being seamed to the can end flange. To rotate the can, the can is preferably clamped between the seaming head and a support (in particular the lifting element), the seaming head being rotated with the seaming shaft about the seaming axis. In the case of two or more symmetrically acting seaming rolls, the balance of power is different than with a single seaming roll, since an opposing seaming roll always supports the seaming head.

Within the scope of the invention, the can can be understood to mean a container which is closed by means of the can seamer and the associated seaming roller. A can can preferably comprise plastic, cardboard or a metal, in particular aluminum or steel.

In principle, the seamer according to the invention can be analogous to the can seamers already known from the prior art, but differs in the folding shaft device or in the sensors (in particular their arrangement). This results in the advantage of the well-known can seamer / seamer with the folding shaft device according to the invention can be modified in order to avoid the disadvantages of the prior art.

In principle, the seamer (or the seaming shaft device) can preferably comprise at least two seaming rollers, preferably with different seaming profiles, so that cans can be seamed according to a double-seam principle, in which the cans are generally seamed in two stages. Each seaming roller is responsible for one step.

According to the invention, a method for fastening a can lid to a can body is also proposed. Here, a folding shaft device according to the invention is provided. The can end and can body are fed to the seaming shaft device. The can lid is positioned on the can body and the can body is positioned on the flow element. The can lid is then seamed with the can body, in particular by means of at least one seaming roller, in particular with two seaming rollers and the seaming head. In particular, the deflection and/or the torsion of the seaming shaft is then detected during the seaming process by means of the sensors in order to monitor the attachment of the can end to the can body and to detect errors. This can also make it possible, for example, to sort out faulty cans.

If the method according to the invention is carried out with a seamer according to the invention, the can end and can body can be brought together at a defined point before the actual seaming process. The can lids are preferably fed in by a gassing rotor on which the can lids lie. The can bodies are fed by a hopper feeder. The can bodies go from the container infeed onto one of the respective flow elements (which are integrated into the carousel). On one revolution of the carousel, the flow elements preferably execute a cam-controlled flow movement in order to Can bodies from below to the can ends and later the seaming head.

The invention is explained in more detail below using exemplary embodiments with reference to the drawings. They show: FIG. 1 a top view of a closure device according to the invention;

Figure 2 is a side view of a folding station;

3 shows a sectional representation of a device according to the invention

folding shaft device;

4A shows a section of a folding shaft device according to the invention without folding means;

4B shows a section of a further folding shaft device according to the invention without folding means;

5 shows an ejection head for a device according to the invention

folding shaft device; 6 shows a folding shaft device according to the invention with an ejection head.

1 shows a plan view of a sealer 1000 according to the invention.

The seamer 1000 for seaming a can comprises a lid feeder 11 for feeding a can lid 101 to a can body 100, a gassing rotor 15 for supplying gas to the can body 100 and a seaming station 14 for closing the can body 100 with the can lid 101. In the operating state, the can end 101 is introduced into the closer 1000 along the arrow C through the end feeder 11 . Here the can lids 101 are arranged on the gassing rotor 15 . The can lids 101 are transported further by rotating the gassing rotor 15 . Then the can bodies 100 are introduced through the container feed 12 into the container receptacles 17 of the gassing rotor 15 . There, the can body 100 is gassed with a gas such as carbon dioxide or nitrogen in the area D and combined with the can lid 101 at 110 .

The gassing takes place along the arrow B with the gas supply 16. After the gassing, the can body 100 with the lid 101 is passed through the container outlet 13 from the gassing rotor 15 to the seaming station 14 and sealed there.

Before the actual seaming process, the can end 101 and the can body 100 are combined as previously described. The can bodies 100 are linearly fed via the container feeder 12 . The can bodies pass from the container feed 12 to one of the respective lifting elements 22 of the folding station 14, which is designed as a carousel (preferably arranged in the form of a vertical shaft). During one rotation of the carousel, the lifting elements 22 carry out a cam-controlled lifting movement, with the can bodies 100 being guided onto the can lids 101 from below. After a certain lifting distance, the can body 100 and the can lid 101 touch and can then be closed.

A seaming shaft device according to the invention in the seaming station 14 allows a seaming process to be monitored when the can body is being closed with the can lid and errors to be detected.

Fig. 2 shows a side view of a seaming station 14 according to the invention with a can body 100 to be closed and a can lid 101. According to FIG. 2 , the folding station 14 includes a clamping device, which includes the flow element 22 and a folding head 2 , the folding head 2 being fastened via the folding head shaft 3 . In addition, the folding station 14 includes at least one folding roller 10 with a folding roller profile 111, which is rotatably mounted on a folding roller shaft 3A. The can lid 101 is centered over the opening of the can body 100 . In the region of the can opening, the can body 100 has a circumferential can flange and the can lid 101 has a circumferential can lid flange.

During the seaming process, the seaming roller 10 is brought into contact with the can flange and the can end flange via the seaming roller profile 111 . Here, the can flange and the can end flange are pressed together by means of a force that acts essentially radially via the seaming roller 10 . The pressing is carried out by a continuous rolling of the seaming roller 10 in the circumferential direction along the circumference of the can opening.

For closing, the can body 100 is rotated by the clamping device in that the seaming head 2 is rotated with the seaming head shaft 3 about the seaming axis X (corresponds to an axial direction).

A sensor according to the invention for monitoring the folding process by measuring a deflection and/or a torsion of the folding shaft can be arranged on the folding roller shaft 3A and/or the folding head shaft 3 . The sensor is particularly preferably arranged at least on the folding head shaft 3 .

Fig. 3 shows a sectional view of a folding shaft device 1 according to the invention. The folding shaft device 1 comprises the folding head shaft 3 rotatable about the folding axis X, a folding head 2 arranged at one end of the folding head shaft 3 and sensors 4 for monitoring the folding process.

The sensors 4 are arranged on the jacket 31 of the folding head shaft 3 in such a way that the folding process can be monitored by the sensors 4 by measuring the deflection of the folding head shaft 3 relative to the folding axis X.

In the operating state, the deflection of the folding head shaft 3 is detected by the sensors 4, preferably continuously. The sensors 4 are preferably force sensors and/or strain sensors, which determine the deflection of the seaming head shaft via a force measurement and/or strain measurement. At least three sensors are preferably arranged along a circumference of the folding head shaft on one side of the folding axis X.

4A shows a section of a folding shaft device 1 according to the invention. Three strain sensors 4 in the form of strain gauges 4 are distributed evenly along the circumference of the folding head shaft 3 and arranged above a fastening point for the folding head, not shown. The deflection can be detected as an elongation of the seaming head shaft 3 .

4B shows a section of a folding shaft device 1 according to the invention. Here, at least two strain sensors in the form of strain gauges 40, 41 are distributed along the circumference of the folding head shaft 3 and arranged at/above the fastening point for the folding head, not shown. In practice, however, the sensors can be located anywhere on the seaming head shaft, such as under and/or in the seaming head. The sensor 40 is arranged in the direction of the fold axis, so that the deflection of the fold head shaft 3 relative to the fold axis can be detected. The sensor 41, on the other hand, is arranged in the circumferential direction of the folding head shaft 3, so that the torsion of the folding head shaft 3 relative to the folding axis can be detected.

The torsion and the deflection can therefore be determined. However, the torsion can be determined by means of the sensor 41 independently of the deflection. Of course, a large number of sensors 40 and/or 41 can also be used.

5 shows an ejection head 18 for a folding shaft device according to the invention in operation. Such an ejection head 18 is known in principle from the prior art.

The ejection head 18 slides along a sliding profile of a folding curve 6. In order to achieve the two functions of holding down the container and ejecting the container, the sliding profile 6 has two sections with a raised level. One section with a higher level of the sliding profile 6 corresponds to the function of holding down the container, in which the container to be closed is held for the closing process by means of the ejection device and centered for the lid closure, and the other section with a higher level of the sliding profile 6 corresponds to the function of container ejection , in which the closed container is ejected from the closing machine by means of the ejection device. While the container is being held down and the container is being ejected, the ejection head 18 is moved along the slide profile 6 and can also rotate about the X axis in the process.

FIG. 6 shows the folding shaft device 1 with the ejection head 18 and an ejection rod 9 to which the ejection head 18 is detachably connected. The ejector rod 9 is movably arranged in the folding head shaft 3 and the ejector head 18 is arranged at a second end of the ejector rod 9 in such a way that the ejector head 18 is arranged between the folding head shaft 3 and the sliding profile for movement along the slide profile (not shown here). During operation, a force can be transmitted to the ejection rod 9 and thus to the can via the ejection head 18 .

Claims

patent claims

Claims 1. A seaming shaft device for a seamer (1000) for fastening a can end (101) to a can body (100), comprising: a seaming shaft (3, 3A) rotatable about a seaming axis (X); a folding means (2,

10); and a sensor (4, 40, 41) for monitoring a seaming process when the can end (101) is attached to the can body (100); characterized in that the sensor (4, 40, 41) is arranged on the folding shaft (3, 3A) in such a way that the folding process is measured by measuring a deflection of the folding shaft (3, 3A) relative to the folding axis (X) and/or via a measurement of a torsion of the folding shaft (3, 3A) can be monitored by the sensor (4, 40, 41).

2. folding shaft device according to claim 1, wherein the sensor (4, 40, 41) for measuring the deflection and / or the torsion of the folding shaft (3, 3A) on a jacket (31) of the folding shaft (3, 3A) is arranged.

3. folding shaft device according to claim 1 or 2, wherein the folding means (2,

10) is detachably arranged at one end of the folding shaft (3, 3A).

4. Folding shaft device according to one of the preceding claims, wherein the sensor (4, 40, 41) is arranged on an inner lateral surface of the folding shaft (3, 3A).

5. Folding shaft device according to one of the preceding claims, wherein the sensor (4, 40, 41) is arranged on an outer lateral surface (31) of the folding shaft (3, 3A).

The seaming shaft device according to any one of the preceding claims, wherein the seaming shaft (3, 3A) is a seaming head shaft (3) and the seaming means (2, 10) is a seaming head (2) for fixing the can end (101) onto the can body (100).

The seaming shaft device according to any one of claims 1 to 6, wherein the seaming shaft (3, 3A) is a seaming roller shaft (3A) and the seaming means (2, 10) is a seaming roller (2) for seaming the can end (101) to the can body (100). is.

8. Folding shaft device according to claim 6, comprising an ejection device with an ejection rod (9), a sliding profile (6) and an ejection head (18), the ejection rod (9) being movably arranged in the folding head shaft (3) and the ejection head (18) is arranged at a second end of the ejector rod (9) in such a way that the ejector head (18) is arranged for movement along the sliding profile (6) between the seaming head shaft (3) and the sliding profile (6).

9. folding shaft device according to one of the preceding claims, wherein the sensor (4, 40, 41) is a force sensor (4, 40, 41) and / or

Strain sensor (4, 40, 41), so that the deflection and/or the torsion of the folding shaft (3, 3A) can be determined by measuring the force and/or strain on the folding shaft (3, 3A).

10. folding shaft device according to claim 9, wherein the sensor (4, 40, 41) is a strain gauge (4, 40, 41) and / or a piezoelectric force sensor (4, 40, 41).

11. folding shaft device according to any one of the preceding claims, wherein the sensor (4, 40, 41) has a first sensor, a second

Sensor and a third sensor includes.

12. Folding shaft device according to claim 11, wherein the first sensor, the second sensor and the third sensor are arranged at different locations along a circumference of the folding shaft (3, 3A), in particular on a flea of the folding axis (X).

13. Folding shaft device according to one of the preceding claims, wherein the sensor (4, 40, 41) is arranged on the folding means (2, 10).

14. Seaming station comprising a seaming shaft device (1) according to one of the preceding claims and a flow element (22), wherein the can body (101) with the can lid (100) is arranged during a seaming process between the flow element (22) and a seaming head (2). .

15. Seaming station according to claim 14, comprising a first seaming roller (10) and in particular a second seaming roller for fastening the can lid (101) to the can body (100).

16. A sealer comprising: a carousel having a plurality of folding shaft devices (1) according to any one of claims 1 to 13; a first feed (12) for can bodies (100), in particular can bodies filled with a product, to the carousel; a second inlet (11) for can ends (101) to the carousel; and a seamed can exit from the carousel.

A method of attaching a can end (101) to a can body (100), comprising: providing a seaming shaft apparatus (1) according to any one of

claims 1 to 13; feeding the can end (101) and the can body (100) to the seaming shaft device (1);

positioning the can end (101) onto the can body (100); positioning the can body (100) on an elevator (22); Seaming the can lid (101) onto the can body (100), in particular by means of at least one seaming roller (10), in particular with two seaming rollers and the seaming head (2).

18. Sensor for a folding shaft device according to any one of claims 1 to 13.