EP4214008A1

EP4214008A1 - Folding shaft assembly for a closing apparatus

Info

Publication number: EP4214008A1
Application number: EP20780123.4A
Authority: EP
Inventors: Pascal Hirt; Alex NIEDERBERGER
Original assignee: Ferrum Packaging AG
Current assignee: Ferrum Packaging AG
Priority date: 2020-09-21
Filing date: 2020-09-21
Publication date: 2023-07-26
Also published as: BR112023000545A2; CA3188750A1; CN116033981A; US20240024944A1; WO2022058032A1

Abstract

The invention relates to a folding shaft assembly (1) for a closing apparatus (1000) for securing a can lid (101) to a can body (100). The folding shaft assembly (1) comprises a folding head (2) for fixing the can lid (101) on the can body (100), and an ejector rod (3) and also an ejector head (4), which is arranged on the ejector rod (3) and is movable with the ejector rod (3) relative to the folding head (2) in an axial direction (X) of the ejector rod (3). The folding shaft assembly (1) also comprises a spring set (5), by means of which the ejector head (4) is spring-mounted on the ejector rod (3). The spring set (5) comprises a slider (6), which is arranged on the ejector rod (3) so as to be movable in the axial direction (X), and a first elastic element (51) arranged between a first contact face (61) of the slider (6) and a first support face (31) of the ejector rod (3) and a second elastic element (52) arranged between a second contact face (62) of the slider (6) and a second support face (42) of the ejector head (4). The slider (6) can be supported on the ejector head (4) in such a way that the ejector head (4) is spring-mounted on the ejector rod (3) by means of the first elastic element (51).

Description

Folding shaft arrangement for a seamer

The invention relates to a folding shaft arrangement for a seamer. The invention further relates to a seamer and a seaming station with a seaming shaft arrangement according to the invention, a spring assembly for a seaming shaft arrangement according to the invention, and a method for closing a can.

When filling beverage cans or food cans, the cans pass through a can seamer after being filled with the 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 several 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). After the can has been clamped in the seaming head, the ejection head is no longer engaged. 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 means of 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 area of the can opening, the can body has a circumferential can flange and the can lid has a circumferential can lid flange. In order to close the can opening with the can end, the can seamer additionally comprises two seaming rollers, each rotatably mounted about an axis, which press the can flange and the can end flange together by means of a force that acts essentially radially, the pressing being carried out by continuous rolling in the circumferential direction along the circumference of the can opening he follows.

In the prior art sealers, the ejection plate may be at least partially located within the seaming head and is movable in a vertical direction relative to the seaming head. When the can end is seamed onto the can body, the cans generally run in the carousel of the seamer around an axis of rotation. The units consisting of the 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.

Depending on the working speed, relatively high centrifugal forces are generated which can throw the can outwards and lead to interruptions in machine operation. This is due to the ejection heads avoided, which follow the raising movement and / or the lowering movement of the can and, through the effect of a force on the can, preferably on the can lid, during the raising / lowering, generate a frictional force which (between the can and a folding plate, which is generated via the Hold-down force (of an ejection head) and then effected with a lifting spring) counteracts the centrifugal force.

This force is preferably defined over a predetermined, set stroke distance of the ejection head (e.g. over a cam-controlled position of the lifting station and the ejection head). The lid and body are held down in a controlled manner before, during and/or after the hemming process.

Even small deviations in the dimensions of the can or lid from the dimensions used as a basis for the set lifting path can cause damage, since the can can buckle if it is not centered precisely when entering/climbing into the seaming head (i.e. if the force on the can is too great because the can is not properly centered). If the force exerted by the ejection head is too small, the result can be insufficient fixation of the can, which can result in imprecise centering. Thus, the cans tend to collapse if not adequately supported by the ejection head as they rise.

EP 3 520 924 A1 discloses a seaming shaft arrangement for a seamer for seaming a can end onto a can body, which includes a seaming head for fixing the can end on the can body. In addition, the folding shaft arrangement includes an ejection bar and an ejection head arranged on the ejection bar. Here, the ejector head with the ejector rod is movable relative to the seaming head in an axial direction of the ejector rod. The ejection head includes a spring assembly, via which the ejection head is spring-mounted on the ejector rod. As a result, a force determined by a spring force of the spring assembly is exerted on the can lid.

Problems with process security due to "undefined" conditions (especially an inconstant, undefined force, so that the can is not kept clean) are to be avoided. It is not possible to set a specific force, which means that the hold-down forces cannot be set correctly due to manufacturing, lid and can tolerances. Uneven hold-down forces are created, which means that the can cannot be held cleanly on the seaming plate while it is rising. In this way, the cans enter the seaming head restlessly/eccentrically and are "forced to be centered" by the seaming head. This creates high forces/stresses in the can body, which can lead to the can collapsing.

The object of the invention is therefore to provide a folding shaft arrangement for a closer and a folding station, in particular a spring assembly for a folding shaft arrangement according to the invention, which avoids the disadvantageous effects known from the prior art. In particular, a seaming shaft arrangement and a seamer are to be provided, by means of which damage to the cans is largely avoided.

The object is achieved by a folding shaft arrangement according to the invention, a spring pack for the folding shaft arrangement according to the invention, as well as a closer and a folding station with the folding shaft arrangement according to the invention and by the method according to the invention.

According to the invention, a seaming shaft arrangement for a seamer for fastening (in particular seaming) a can end to a can body is provided, comprising a seaming head for fixing the can end the can body. The folding shaft arrangement also includes an ejection bar and an ejection head arranged on the ejection bar. The ejector head can be moved with the ejector rod relative to the seaming head in an axial direction of the ejector rod. The folding shaft arrangement also includes a spring assembly via which the ejector head is resiliently mounted on the ejector rod.

The folding shaft arrangement according to the invention is characterized in that the spring assembly includes a slider which is arranged on the ejection rod so as to be movable in the axial direction. In addition, the spring assembly comprises a first elastic element arranged between a first contact surface of the slider and a first support surface of the ejector rod and a second elastic element arranged between a second contact surface of the slider and a second support surface of the ejector head. In this case, the slider can be supported on the ejection head in such a way that the ejection head can be resiliently mounted on the ejection rod via the first elastic element (or is mounted depending on an operating state).

The ejector head is preferably movably attached/arranged at one end of the ejector rod, with the spring assembly being arranged in particular first at the end of the ejector rod and then the ejector head, so that the ejector head is resiliently mounted via the spring assembly at the end of the ejector rod.

Due to the slider according to the invention with the two elastic elements, the folding shaft arrangement according to the invention has the particular advantage over the prior art that a staggered transmission of force is possible for centered fixing of the can lid and/or can body. The can lid can preferably first be acted upon by a second spring force of the second elastic element (which preferably serves to "guide" the can lid in the area of a lid guide with a slight force) and then subjected to a first spring force of the first elastic element, in order to hold the can in place when it rises, so that it remains centric until the can in retracts the folding head. The slider is supported on the ejection head (or part of the ejection head) in such a way that the ejection head is resiliently mounted on the ejection rod via the first elastic element (i.e. by moving the slider in the axial direction to the ejection head or by Movement of the ejector head in the axial direction to the slider, e.g. when the can is approached).

Thus, compared to EP 3 520 924 A1, in particular by the slider according to the invention, a better distribution of force is made possible (hold-down forces can therefore be defined correctly in order to enable uniform hold-down forces), which means that damage such as buckling of the can when it enters the seaming head due to a lack of centering of the box can be prevented. Furthermore, process reliability of the machine can be increased.

In an embodiment of the invention, the folding shaft arrangement can also comprise a folding shaft on which the folding head is arranged (and by which the folding head can be rotated). Both the ejector rod and the ejector head can be arranged at least partially in an interior of the seaming shaft and/or seaming head, where they are movable relative to the seaming head and/or the seaming shaft in the axial direction (and at least the ejection head also moves out of the interior can be). Here, the ejector head together with the ejector rod can also be resiliently mounted on the folding shaft (as is known in the prior art).

The slider can preferably be supported on the ejector head in such a way that the ejector head is resiliently mounted on the ejector rod exclusively via the first elastic element, since a force between Can and folding shaft arrangement is transferred via the ejection head to the slider and then to the first elastic element (and no longer via the second elastic element to the slider and then to the first elastic element).

In a particularly preferred embodiment of the invention, the ejection head can comprise a fastening element and an ejection element. The ejector element is movably attached to the ejector rod via the fastening element. The ejector element and the fastening element are firmly screwed to one another, in particular via a thread. In principle, the ejector element can be designed as a block or preferably as an ejector plate which, in an operating state, comes into contact with the can body via the can lid. If the ejection head includes the fastening element, forces can be transmitted from/via the fastening element (in particular directly) to the slider, since the slider can then be supported on the ejection head via the fastening element (depending on the compression of the second elastic element).

Instead of an ejection block screwed directly onto the ejection rod, the ejection head is provided with a spring assembly as a resilient module and preferably with the ejection plate (also ejection pad) screwed on. The spring package mentioned does not have to be replaced when changing the format. In the case of format changes, in particular only the ejector plate screwed onto the lower end of the spring assembly (which can be made of stainless steel, for example) can be exchanged.

In practice, the first elastic element can be a first spring, in particular a first spiral field, and/or the second elastic element can be a second spring, in particular a second spiral spring. In addition, a first spring force of 70-160 N, in particular 80-150 N, can be transmitted to the ejection head by the first elastic element be (in the operating state). In addition, a second spring force of 5-30 N, in particular 10-20 N, can be transmitted to the ejection head (in the operating state) by the second elastic element. The spring assembly thus acts particularly preferably in two stages with different spring rates and preload forces. In a particularly preferred embodiment, the setting for different lid formats can be carried out with a first stage (second elastic element) with approx. 10-20N and a spring deflection of up to 1 mm. Due to a flat spring characteristic of only approx. 1 N/mm, the effective force changes only slightly over the defined spring deflection. This leads in particular to a predefined, uniform clamping force on the lid. A lid geometry no longer has any influence as long as a hold-down height is in the range of the spring deflection of the second elastic element.

As soon as the first stage has covered its full spring travel or until the first stage has covered a predeterminable spring travel (by compressing the second elastic element and by supporting the slider), the ejection head can transfer forces (in particular directly) to the slider, since the slider is then supported on the ejection head.

By supporting the slider, the first elastic element is then (in particular exclusively) active and presses against a lifting direction of the can. What was done in the prior art via a cam-controlled position of a lifting station and the ejection block should lead to a controlled and definable force when the can is clamped between the components mentioned by means of a spring assembly.

The first elastic element is preferably significantly more prestressed and acts in particular between 80-150N on a spring deflection of up to 2mm, depending on the element used. Thus, a reliable centering of the can can be achieved when climbing to the seaming head, so that the buckling of cans can be prevented by the seaming head, even with cans with a thinner can material.

The slider can particularly preferably be designed as a sleeve which is arranged around the second elastic element. Alternatively or additionally, the slider can be designed as a sleeve, which is arranged between the second elastic element and the ejection rod.

The first elastic element and the second elastic element are preferably arranged on different sides of the slider with respect to the axial direction, in particular on different sides of a circumferential projection of the slider. In this case, the first and second contact surfaces can be arranged essentially parallel to one another and, in particular, also orthogonally to the axial direction.

The attachment member may comprise an attachment sleeve which is (at least partially) arranged around the ejection rod, the slider, the first elastic element and the second elastic element, the attachment sleeve comprising a projection on which the slider is supportable such that the ejection head ( in particular exclusively) is resiliently mounted on the ejector rod via the first elastic element.

In practice, the fastening element can be arranged (fixed) on the ejector rod, in particular by means of a screw connection or clamp connection, the fastening element preferably being arranged movably in the axial direction via a sliding bush. A clamping screw is preferably used, which is introduced into a corresponding thread on the ejector rod for arranging. In this case, however, the fastening element is not firmly screwed to the ejector rod. This sliding bush, which is located between the ejector rod and the screw connection, can Travel spring deflection (of the first and second elastic element) on the sliding surface of the fastening element. This sliding surface is limited in particular by the screw connection on a first side and by the ejector rod and/or the preload sleeve on the other side, so that the movement of the fastening element is also limited. The ejector plate can then be screwed, clamped or bolted/pinned to the fastener.

The ejector rod may include a biasing sleeve fixed to the ejector rod and including a projection by which a travel of the slider (particularly when the slider is the sleeve) is limited in the axial direction via the biasing sleeve. The spring deflection of the first elastic element can thus be limited by the pretensioning sleeve, so that the slider cannot be moved any further in the direction of the end of the ejector rod. A prestressing shoulder is thus formed by the prestressing sleeve, on which the slider can be supported.

According to another embodiment, the ejection element can be arranged such that it can rotate about an axis of rotation running in the axial direction relative to the fastening element. In this way, a rotation relative to the fastening element or relative to the ejection rod can take place during the closing.

The first support surface (on which the first elastic element is supported on the ejector rod) can be designed as a step, in particular as a disk arranged between the step and the first elastic element.

The seaming shaft arrangement according to the invention can also comprise a first seaming roller and in particular a second seaming roller for seaming the can end onto the can body. In addition, the seaming shaft assembly may include a lifting element, wherein the can body with the can lid is arranged during a seaming process between the lifting element and the seaming head, in particular between the lifting element and the ejection head.

According to the invention, a seamer for closing a can comprising a seaming shaft arrangement according to the invention is also proposed. The seamer is therefore particularly preferably a can seamer. The seamer according to the invention can include a carousel with a large number of folding shaft arrangements according to the invention, as well as 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 arrangement) 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 lid flange. To rotate the can, the can is preferably clamped between the seaming head (or ejection head) and a support (in particular the lifting element), with the seaming head being rotated with the seaming shaft about the seaming axis (which in particular runs parallel to the axial direction).

Within the scope of the invention, the can can be understood to mean a rotationally symmetrical 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 arrangement or the spring assembly. This results in the advantage that the known can seamer/sealer can be modified with the folding shaft arrangement according to the invention in order to avoid the disadvantages of the prior art.

In practice, the can seamer preferably comprises, as in the prior art, a clamping device made up of a seaming head and a lifting element, with which the can is fixed in the axial and radial direction for seaming and can be rotated in the circumferential direction.

In principle, the seamer can preferably comprise at least two seaming rollers, preferably with different seam 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. In the method according to the invention, a folded shaft arrangement according to the invention is provided. The can end and can body are fed to the seaming shaft assembly. The can lid is positioned on the can body and the can body is positioned on the lifting element. A spring force is exerted on the can end with the spring-loaded ejection head until the can is pressed into the seaming head together with the loosely attached end by the lifting movement of the lifting element (while maintaining the spring force). Then the can end is seamed to the can body by means of at least one seaming roller. During folding, the ejection head is not (or no longer) engaged. Finally, the can is removed from the seaming shaft arrangement. 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 lifting elements (which are integrated into the carousel). During one rotation of the carousel, the lifting elements preferably carry out a cam-controlled lifting movement in order to retract the can body from below onto the can end and later onto the seaming head.

After a certain lifting distance, the can body comes into contact with the can lid. The ejector heads (preferably the ejector elements) are used so that the combination of can body and can lid can make the rest of the ascent together.

The ejector head is fixed, for example by means of a thread, to the ejector rod, which makes a linear movement along the axial direction within a folding shaft (the folding head is fixed to the folding shaft). In the downward movement, preferably cam-controlled, the can end is first clamped in the end feed (by the second force of the second elastic element). As soon as the can body has entered the can end, the ejection head changes the direction of the stroke and moves up smoothly with the lifting element (whereby the can end is fixed centered on the can body by the first force of the first elastic element). The supporting function of the ejector element ends when the can body and can end enter the seaming head. From this moment on, the can is clamped between the lifting element and the seaming head. The actual folding process is then carried out. The invention and the prior art are explained in more detail below using exemplary embodiments with reference to the drawings.

1 shows a plan view of a sealer according to the invention;

Figure 2 is a side view of a folding station;

3A shows a sectional illustration of a first embodiment of a folding shaft arrangement according to the invention under the influence of a second elastic element;

FIG. 3B shows a further sectional illustration of the embodiment according to FIG. 3A under the influence of a first elastic element;

4 shows an exploded view of an ejection head according to the invention, in which a spring assembly according to the invention is also shown;

5 shows a schematic representation of a second embodiment of a folding shaft arrangement according to the invention.

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

The seamer 1000 for seaming a can comprises a lid feed 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 . be 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 area D and combined with the can lid 101 .

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.

So that the rest of the stroke can take place together without disturbances, an ejection head according to the invention (not shown here) is used to clamp the can body 100 and the can lid 101 .

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 lifting element 22 and a folding head 2, the folding head 2 over the folding shaft 3' is fixed. In addition, the folding station 14 comprises at least one folding roller 10 with a folding roller profile 111, which is rotatably mounted via a 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 shaft 3' around the seaming axis X (corresponds to an axial direction).

3A and 3B show sectional views of a first embodiment of a folding shaft arrangement 1 according to the invention.

The folding shaft arrangement 1 comprises the folding head 2, which is arranged on the folding shaft 3', and an ejector rod 3 and arranged on the ejection rod 3 and with the ejection rod 3 relative to the folding head 2 (and the folding shaft 3') in an axial direction X of the Ejector bar 3 movable ejector head 4. The ejector bar 3 is movably arranged essentially in the interior of the folding head 2 (and folding shaft 3').

The folding shaft arrangement 1 further includes a spring assembly 5 via which the ejector head 4 is resiliently mounted on the ejector rod 3 . The spring assembly 5 comprises a slider 6 arranged on the ejector rod 3 so that it can move in the axial direction X, and a first elastic element 51 arranged between a first contact surface 61 of the slider 6 and a first support surface 31 of the ejector rod 3. The spring assembly 5 also comprises a second elastic element 52 arranged between a second contact surface 62 of the slider 6 and a second support surface 42 of the ejection head 4.

According to the invention, the slider 6 can be supported on the ejection head 4 (in an operating state) in such a way that the ejection head 4 is resiliently mounted on the ejection rod 3 exclusively via the first elastic element 51 .

In the embodiment shown, the first elastic element 51 is a first coil spring 51 and the second elastic element 52 is a second coil spring 52.

The ejection head 4 comprises a fastening element 43 and an ejection element 41 which form a coherent part. The ejector head 4 is movably arranged on the ejector rod 3 via the fastening element 43 (fastening not shown here).

The fastening element 43 has a sleeve 45 which is arranged around the ejection rod 3 , the slider 6 , the first spiral spring 51 and the second spiral spring 52 . The sleeve 45 has a projection 44 which is directed in the direction of the ejector rod 3 and on which the slider 6 can be supported (on a slider support surface). This projection 44 thus includes the slider support surface. This makes it possible for the ejector head 4 to be resiliently mounted on the ejector rod 3 via the first spiral spring 51 , since force is transmitted between the first spiral spring 51 and the ejector element 41 via the slider 6 . 50, a staggered transmission of force is made possible, since when the can 100, 101 is approached by the second spiral spring 52, first a second spring force of 10-20 N (to keep the can lid 101 in a lid guide), and then to fix the can lid 101 centered on a first spring force of 80-150 N can be exerted on the can body 100 by the first spiral spring 51 . Thus, the can lid 101 is held centered on the can body 100 by a defined, uniform force when it is moved up to the seaming head 2, so that any buckling when entering the seaming head 2 can be avoided.

3A shows the can end 101 held in a lid guide (not shown). In this case, the cover 101 is acted upon by the ejection element 41 with the second spring force of the second spring 52 . In this way, the lid 101 can be placed on the can body 100 in a centered manner.

As soon as the can body 101 has entered the can lid 100, the ejector head 4 changes the direction of the stroke and moves evenly with the lifting element (below the can 100, 101, not shown) upwards, with the can lid 101 being held in place by the first force of the first elastic feather

51 is fixed centered on the can body 100. For this purpose, the lid 101 is acted upon by the ejection element 41 exclusively with the first spring force of the first spring 51 and can thus enter the seaming head 2 centered with the can body 100 . The slider 6 is supported on the projection 44 of the ejection head 4 so that only the first spring force acts.

3B shows the can lid 101 as it is arranged centered on the can body 100 and engaged by the seaming head 2 . From this moment the can 100 , 101 is clamped between the lifting element (not shown) and the seaming head 2 . The actual folding process is then carried out. FIG. 4 shows an exploded view of the individual elements of the ejection head 4 according to the invention according to FIGS. 3A and B, in which, in addition to the ejection head 4, the spring assembly according to the invention is shown. However, the ejector head 4 is not shown in its entirety, since parts such as the ejector element are not shown at the lower end.

The first contact surface 61 of the slider 6 and the second contact surface 62 of the slider 6 are located on opposite sides of a circumferential ring of the slider 6.

An O-ring seals a joint between the ejection element 41 and the fastening element 43 . A slide bush (or slide bearing) 92 is fastened with a screw 8 .

Thus, the fastening element 43 is not screwed to the ejector rod 3, but is movably arranged thereon (via the sliding bush 92, which is limited at the top and bottom, or on two sides with respect to the axial direction X). The movement of the fastening element 43 on the ejector rod 3 is limited by the preload sleeve 7 and the screw 8 . The fastening element 43 thus slides on the sliding bush 92.

The fastening element can travel the entire spring deflection (of the first and second elastic element) on a sliding surface of the sliding bush 92 . This sliding surface is delimited by the screw 8 on a first side and by the preload sleeve 7 on the other side.

The first support surface is on the disk 310 which, as shown in Figure 3, is supported on a step 311 of the ejector rod.

FIG. 5 shows a schematic representation of a second embodiment of a folding shaft arrangement 1 according to the invention 3A and B, but the slider 6 is a sleeve 6, which is arranged around the second spiral spring 52 and can transfer the first spring force directly to the ejector head 4, which is movably arranged on the ejector rod 3. The power can be transmitted from the first spring 51 when the sleeve 6 completely encloses the second spring 52 and is supported on the ejection element 41 .

Claims

patent claims

1 . Seaming shaft assembly for a seamer (1000) for attaching a can end (101) to a can body (100) comprising: a seaming head (2) for fixing the can end (101) on the can body (100), and an ejector rod (3) and an the ejection head (4) arranged on the ejection bar (3) and movable with the ejection bar (3) relative to the folding head (2) in an axial direction (X) of the ejection bar (3), the folding shaft arrangement (1) further comprising a spring assembly (5). , via which the ejector head (4) is resiliently mounted on the ejector rod (3), characterized in that the spring assembly (5) has a slider (6) arranged movably on the ejector rod (3) in the axial direction (X), and a between a first contact surface (61) of the slider (6) and a first support surface (31) of the ejector rod (3) arranged first elastic element (51) and between a second contact surface (62) of the slider (6) and a second support surface ( 42) des Ejection head (4) arranged second elastic element (52), wherein the slider (6) can be supported on the ejection head (4) in such a way that the ejection head (4) resiliently on the ejection rod (3) via the first elastic element (51). is stored.

2. Folding shaft arrangement according to claim 1, wherein the slider (6) can be supported on the ejection head (4) in such a way that the ejection head (4) is resiliently mounted on the ejection rod (3) exclusively via the first elastic element (51).

3. folding shaft arrangement according to claim 1 or 2, wherein the slider (6) is a sleeve (6) which is arranged around the second elastic member (52).

4. Folding shaft arrangement according to claim 1 or 2, wherein the slider (6) is a sleeve (6) which is arranged between the second elastic element (52) and the ejector rod (3).

The folding shaft assembly according to claim 4, wherein the ejector rod (3) comprises a bias sleeve (7) fixed to the ejector rod (3) and comprising a protrusion through which a travel of the slider (6) in the axial direction (X) is limited by the preload sleeve (7).

6. Folding shaft arrangement according to one of the preceding claims, wherein the first support surface (31) is configured as a step (311), in particular as a disc (310) arranged between the step (311) and the first elastic element (51).

7. Folding shaft arrangement according to one of the preceding claims, wherein the ejection head (4) comprises a fastening element (43) and an ejection element (41) and the ejection element (41) is movably fastened to the ejection rod (3) via the fastening element (43).

8. Folding shaft arrangement according to claim 7, wherein the fastening element (43) comprises a fastening sleeve (45) which is arranged around the ejector rod (3), the slider (6), the first elastic element (31) and the second elastic element (52). , wherein the fastening sleeve (45) comprises a projection (44) on which the slider (6) can be supported in such a way that the ejection head (4) is resiliently mounted on the ejector rod (3) via the first elastic element (51). Folding shaft arrangement according to Claim 7 or 8, in which the fastening element (43) is fastened to the ejector rod (3), in particular is fastened to the ejector rod (3) by means of a screw connection (8). Folding shaft arrangement according to one of Claims 7 to 9, in which the ejection element (41) is arranged so as to be rotatable about an axis of rotation running along the axial direction (X) relative to the fastening element (43). Folding shaft arrangement according to one of Claims 7 to 10, in which the ejection element (41) is firmly connected and/or screwed and/or clamped to the fastening element (43). Folding shaft arrangement according to one of Claims 7 to 11, in which the fastening element (43) is arranged so as to be movable in the axial direction (X) on a sliding bush (92) arranged on the ejector rod (3). Folding shaft arrangement according to one of the preceding claims, wherein the first elastic element (51) is a first spring (51), in particular a first spiral field (51) and / or the second elastic element (52) is a second spring (52), in particular a second Spiral spring (52) is. Folding shaft arrangement according to one of the preceding claims, wherein a first spring force of 70-160 N, in particular 80-150 N, is exerted on the ejection head (4) by the first elastic element (51). is transferrable and wherein a second spring force of 5-30 N, in particular 10-20 N, can be transferred to the ejection head (4) by the second elastic element (52).

15. Seaming station comprising a seaming shaft arrangement (1) according to one of the preceding claims comprising a first seaming roller (10) and in particular a second seaming roller for fastening the can end (101) to the can body (100).

16. Seaming station according to claim 15 comprising a lifting element (22), wherein the can body (101) with the can lid (100) is arranged during a seaming process between the lifting element (22) and the seaming head (2), in particular between the lifting element (22) and the ejection head (4).

17. Sealer, comprising: a carousel with a plurality of folding shaft arrangements (1) according to any one of claims 1 to 14; 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.

18. A method of attaching a can end (101) to a can body (100), comprising:

Providing a folded shaft arrangement (1) according to any one of claims 1 to 14;

Feeding the can end (101) and the can body (100) to the seaming shaft assembly (1);

positioning the can lid (101) onto the can body (100); positioning the can body (100) on an elevator (22); Exerting a spring force on the can lid (101) with the resiliently arranged ejection head (4);

Seaming the can lid (101) onto the can body (100) by means of at least one seaming roller (10), in particular with two seaming rollers, and the seaming head (2); synchronous lowering of the ejection head (4) and the lifting element (22) while maintaining the spring force on the can lid (101); lifting the ejection head (4) from the can lid (101); and discharging the seamed can from the seaming shaft assembly (1). A method according to claim 18, wherein the can end (101) is guided in a portion of a end guide by means of the second spring force and is guided onto the can body (100), the can body

(100) and the can lid (101) are lifted with the lifting element (22) and when lifting the first spring force is exerted with the ejector head (4) on the can lid (101), with the lifting the first spring force on the can lid

(101) is exerted by supporting the slider (6) on the ejection head (4) in such a way that the ejection head (4) is resiliently mounted on the ejection rod (3) via the first elastic element (51). ederpaket for a folded shaft arrangement (1) according to any one of the claims

1-14 comprising: the slider (6) and the first elastic element (51) arranged on the first contact surface (61) of the slider (6) and the second elastic element arranged on the second contact surface (62) of the slider (6). (52).