EP3520924A1 - Spring biased knockout pad - Google Patents

Abstract

The invention relates to a folding arrangement for folding a can lid to a can body with a chuck and a relative to the chuck in an axial direction of the chuck movable ejector block, wherein the ejection block comprises a resiliently arranged holding element. Furthermore, the invention relates to a method for folding a can lid to a can body with the device according to the invention.

Description

Field of the invention

The invention relates to a folding arrangement for folding a can lid to a can body.

State of the art

Because in the field of can closure also in the German-speaking countries the terms from the English-speaking area are often used, the respective corresponding English terms are also given in parentheses in the following or they are used synonymously in the text.

When filling beverage cans, the cans, after filling, pass through a can seamer in the form of a seammer, the filled can bodies entering via a feed path and entering through a further feed path. The folding device usually has a plurality of similar stations arranged in the form of a carousel, so-called folding stations (also referred to below as folding arrangement), in each of which a can is closed with a lid. The lids are guided on the cans and held with an ejector block (knockout pad) of a folding chuck on it. This ejection block is designed such that a holding element (for example a plate) is formed in the region which comes into contact with the can lid. This holding also serves to fix the cans against breaking out of the circular path traversed by the cans in the capper due to the centrifugal force. In the case of the capper, the cans with the lid are folded at the edge by means of capping rollers and thus closed. As a rule, the can with the lid also rotates around its own symmetry axis.

The knockout pads are located inside the chuck and are vertically movable relative to the chuck. When folding a can lid to a can body (also referred to as flanging a lid with a can body) The cans in the carousel-shaped machine area run around an axis of rotation. On the perimeter, the units are made of Chuck (including Knockout Pad) and 2 locking rollers. Depending on the design of the capper usually between 4 and 12 units are arranged. When revolving the carousel, the lid is placed on the can body, the filled can body with the lid raised against the chuck, the flanging successively performed by first and second locking roller. At the end of the cycle, the filled can is lowered again and removed from the chuck. Depending on the operating speed, relatively high centrifugal forces arise, which can throw the can outwards and possibly lead to interruptions in operation. To avoid this, the aforementioned knockout pads are used, which perform the lowering movement of the filled can with and counteract by constant light pressure, for example, on the central portion of the can lid, during lowering the centrifugal forces. For problem-free operation, however, a very accurate design and adjustment of the knockout pads is required.

The applied force is thereby defined over a predetermined, set stroke of the knockout pad (in cooperation with the elastic properties of the lid and the can), which already at small deviations of the can or lid dimensions of the dimensions used for the set stroke on dimensions Damage may result, for example, if the pressure is too great, or it may cause disturbances of the closing due to poor localization of the can when the pressure is too low. If the stroke of the holding plate, which presses from above onto the lid, is too short, only an insufficient fixing of the can takes place. If the stroke is too large, there is a bending of the lid, which is also undesirable. In certain types of covers, it may even lead to the destruction of opening arranged in the lid opening means for opening the can.

For larger deviation from a set type of cans due to different types of cans or lids to be folded, time-consuming conversion and / or adjustment work is necessary for setting the stroke distance of the knockout pads. As a result of product innovation in the meantime many different designs of the can lids, in particular in relation to the Height of the contact points or contact surfaces of the lid where the knockout pad attaches.

Description of the invention

The object of the invention is to overcome the disadvantages mentioned at least partially.

This object is achieved by a folding arrangement for folding a can lid to a can body according to claim 1.

The folding arrangement according to the invention for folding a can lid onto a can body comprises a seam chuck and an ejection block movable relative to the chuck in an axial direction of the seam chuck, the ejection block comprising a resiliently arranged holding element.

The folding arrangement according to the invention has the advantage over the prior art that a force determined by the spring force of the arrangement is exerted on the can lid (and the force exerted is not determined by the fixed stroke as in the prior art). The contact with the can lid is carried out in the resilient region (ie, not until the end of the spring travel with a hard stop), so that the force exerted on the lid force is defined by the suspension, for example by the spring constant of a spring and by the through set stroke fixed rest position / bias on contacting.

The folding arrangement according to the invention can thus be developed to the effect that the holding element is provided for exerting a force determined by a spring force of the resilient arrangement on a can lid. Preferably, the stroke of the ejection block is adjusted so that the contacting of the holding element and the can lid takes place in a central region of the available spring travel. Accordingly, the applied spring force is in a central region of the available spring force range. In order to There is in both directions of the central position an adjustment or evasive margin, so a "soft" force application in contrast to the "hard" force application according to the prior art.

The ejection block may be disposed on an ejection rod, and the ejection rod may be movable together with the ejection block in the axial direction relative to the chuck. This provides a simple way to move the spring-loaded holding element relative to the chuck.

The folding arrangement according to the invention can be further developed in that the ejection block further comprises a fastening element, wherein the fastening element is attached to the ejection rod. The ejection block can be firmly connected in this way with the ejector rod.

This can in turn be further developed in that the retaining element is mounted resiliently relative to the fastening element. The resilient arrangement of the retaining element according to the invention is thus realized between the fixedly connected to the ejector rod fastener and the retaining element.

According to another embodiment, the holding element can be arranged rotatable about an axis of rotation extending in the axial direction relative to the fastening element. In this way, a necessary during the closure rotation relative to the fastener or the ejector rod can be done. According to the prior art, such a rotation is effected only by rotation of the ejection rod together with the knockout pad.

Furthermore, a lifting element may be provided, wherein the can body is arranged with the can lid between the lifting element and the chuck during a folding operation. With the lifting element, the can body (possibly together with the can lid) raised and pressed against the chuck.

During the folding operation, the spring force of the resilient arrangement of upper can be exerted on the can lid with the holding element of the ejection block to locate this on the can body.

According to another embodiment, the ejection block and / or the ejection rod can be moved synchronously with the lifting element during an ejection operation, with the holding element of the ejection block, the spring force of the resilient arrangement on the can lid is exercised from above and with the lifting element an equal counterforce on the Can body is exercisable from below. In this way, the can body can be moved with the can lid on a defined path to the chuck and / or moved away from the chuck after folding.

Another development consists in that at least one spring, in particular at least one spiral spring, is provided between the retaining element and the ejection rod or between the retaining element and the fastening element. One or more springs (coil springs) can provide the resilient arrangement. For example, a spiral spring can be used, which contacts the fastening element at one end and the retaining element in a respective circumferential region at an end opposite thereto. Alternatively or additionally, an elastomer spring (for example in the form of a rubber ring) or a leg spring may be provided for providing the spring arrangement of the retaining element.

According to another embodiment, the spring force of the resilient arrangement of the holding element between 10 and 50 N and / or is a spring travel of the resiliently arranged holding element between 0.2 and 2.0 mm. These are preferred values, on the one hand provide a secure support of the can lid or the folded box and on the other avoid damage to the lid or the box.

Another development consists in that the folding arrangement further comprises at least one folding roller, in particular two folding rollers.

The invention further provides a folding device comprising: a carousel having a plurality of folding arrangements according to the invention or according to one of the further developments; a first inlet for can bodies, in particular can bodies filled with a product, to the carousel; a second inlet for can lid to the carousel; and a spout for folded cans from the carousel.

The above object is further achieved by a method for folding a can lid to a can body according to claim 14.

The inventive method for folding a can lid to a can body comprises the steps of: supplying the can lid and the can body to a folding arrangement of a folding device; Positioning the can lid on the can body; Positioning the can body on a lifting element; Exerting a spring force on the can lid with a resiliently arranged holding element of an ejection block movable relative to a chuck in an axial direction of the chuck; Folding the can lid to the can body by means of at least one folding roller, in particular with two folding rollers, and the folded chuck; synchronous lowering of the ejection block and the lifting element while maintaining the spring force on the can lid; Lifting the ejector block from the can lid; and discharging the folded can from the folder.

Furthermore, the invention thus relates to a method for folding a can lid to a can body with the device according to the invention.

The cited developments can be used individually or combined as claimed suitable.

Further features and exemplary embodiments and advantages of the present invention will be explained in more detail with reference to the drawings. It is understood that the embodiments do not exhaust the scope of the present invention. It is further understood that some or all of the features described below may be combined with each other in other ways.

Brief description of the drawings

Fig. 1 A, B

shows a folding arrangement according to the prior art.

Fig. 2 A, B, C

shows an embodiment of the folding arrangement according to the invention

embodiments

Fig. 1A . B shows a folding arrangement 100 according to the prior art.

The illustrated prior art seam assembly 100 (seamer) is for folding / flanging the edge of a metallic can lid 11 with the upper edge of a metallic can body 12 (in other words, folding the can lid 11 against the can body 12) to form a sealed can 10, for example, a beverage can to provide. The folding assembly 100 includes a chuck 20 and a knockout pad 50 movable relative to the chuck 20 in an axial direction of the chuck 20. The ejection block 50 is fixed to an ejection rod 40, and the ejection rod 40 can be moved together with the ejection block 50 in the axial direction relative to the chuck 20.

The can lid 11 is folded onto the can body 12 using the known double-seam method. The double folding operation is typically performed on a folding device having a plurality of folding assemblies 100. Each creasing assembly 100 includes such a (rotatable) creasing chuck 20 which serves as an anvil to support the can body 12 while two rotatable creasing rollers 30 perform creasing using a special groove geometry to produce a conventional double seam. The ejection of the folded can 10 is achieved through the use of the ejector block 50, which acts on the can lid 11 to bring the can 10 out of engagement with the chuck 20. The can is supported from below by a lifting element 60.

The disadvantage here is that a faulty adjustment of the stroke of the ejector rod 40 with the ejector block 50 on the one hand damage the lid or on the other hand may limit the function of the ejection block 50, which can lead to production disturbances. For example, opening elements 15 on the can lid 11, which serve to open the can to be opened by a user, may be damaged. In the case of conventional beverage cans, for example, the rivet with which the tab is attached to open, be damaged. Other types of damage can occur especially in resealable cans, as some plastic element are used. In addition, when changing between different types of covers - as already mentioned - by changing parts or due to the need to change settings changeover times incurred.

FIGS. 2A . B . C show a folding arrangement 200 according to the invention.

The folding arrangement 200 according to the invention for folding a can lid 11 against a can body 12 comprises a chuck 20 and an ejection block 50 movable relative to the chuck 20 in an axial direction of the chuck 20, the ejection block 50 comprising a resiliently arranged holding element 51. The ejection block 50 is disposed on an ejection rod 40, and the ejection rod 40 is movable together with the ejection block 50 in the axial direction relative to the chuck 20. The ejector block 50 further includes a fastener 52 with the fastener 52 attached to the ejector rod 40. The holding element 51 is resiliently mounted relative to the fastening element. The resilient arrangement of the retaining element according to the invention is thus realized between the fastening element 52 fixedly connected to the ejection rod 40 and the retaining element 51.

Between the retaining element 51 and the fastening element 52 at least one spring 55 is provided (alternatively between the retaining element 51 and the ejection rod 40). One or more springs (coil springs) can provide the resilient arrangement. For example, as in this embodiment, a coil spring 55 can be used which at one end of the fastener 52 and at an opposite end of the holding member 51 contacted in a respective edge region.

The spring force of the resilient arrangement of the holding member 51 may be between 10 and 50 N. The spring travel of the resiliently arranged holding element 51 can be between 0.2 and 2.0 mm. These are preferred values which on the one hand provide a secure holding of the can lid 11 or the folded can 10 and on the other hand avoid damage to the lid 11 or the can 10.

The contact of the holding member 51 with the can lid 11 is performed in a resilient region, so that the force exerted on the lid 11 force is defined by the suspension, in this embodiment, by the spring constant of a spring 55 and by the set stroke with the rest position / Preload when contacting. The retaining element 51 is provided for exerting a force determined by the spring force of the spring 55 on a can lid 11. The stroke of the ejection block 50 is set so that the contacting of the holding member 51 and the can lid 11 in a central region of the available spring travel (see double arrow) takes place. Accordingly, the applied spring force is in a central region of the available spring force range. Thus there is an adjustment or evasion margin in both directions from the middle position.

Furthermore, a lifting element 60 is provided, wherein the can body 12 is arranged with the can lid 11 between the lifting element 60 and the chuck 20 during a folding operation. With the lifting element 60, the can body 12 (possibly together with the can lid 11) raised and pressed against the chuck 20. During the folding operation, the spring force of the resilient arrangement (by the spring 55) can be exerted on the can lid 11 from above with the holding element 51 of the ejection block 50 in order to hold the can lid 11 on the can body 12.

The ejection block 50 can be moved together with the ejection rod 40 during an ejection operation in synchronism with the lifting member 60, wherein with the holding member 51 of the ejection block 50, the spring force of the resilient arrangement of is exerted on top of the can lid 11 and with the lifting element 60 an equal amount of force is exerted on the can body 12 from below. In this way, the can body 12 can be moved with the can lid 11 on a defined path to the chuck 20 and are moved away after folding of the chuck 20 as a folded can 10 again (see Fig. 2B ). After the folded box 10 has been brought out of the chuck 20 in this way, the can 10 clamped between the holding member 51 and the lifting member 60 is released (by raising the ejection bar 40) by lifting the holding member 51 (see FIG Fig. 2C ) to then discharge them from the folding assembly 200 and then also from the folding device.

The illustrated embodiments are merely exemplary and the full scope of the present invention is defined by the claims.

Claims (15)

Folding arrangement for folding a can lid to a can body, comprising: a chuck; a discharge block movable relative to the chuck in an axial direction of the chuck; characterized in that the ejection block comprises a resiliently arranged holding element. Folding assembly according to claim 1, wherein the holding element is designed to exert a force determined by a spring force of the resilient force on a can lid. The folder assembly according to claim 1 or 2, wherein the ejection block is disposed on an ejection rod, and the ejection rod is movable together with the ejection block in the axial direction relative to the seam chuck. The folder assembly of claim 3, wherein the ejector block further comprises a fastener, the fastener attached to the ejector rod. Folding arrangement according to claim 4, wherein the retaining element is resiliently mounted relative to the fastening element. Folding arrangement according to claim 4 or 5, wherein the holding element is rotatably disposed about an axis of rotation extending in the axial direction relative to the fastening element. Folding arrangement according to one of claims 1 to 6, further comprising a lifting element, wherein during a folding operation, the can body is arranged with the can lid between the lifting element and the seaming chuck. Folding arrangement according to claim 7, wherein during the folding operation with the holding element of the ejection block, the spring force of the resilient arrangement can be exerted on the can lid from above. Folding arrangement according to claim 7 or 8, wherein the ejection block and / or the ejection rod during an ejection operation are movable in synchronism with the lifting element, wherein with the holding element of the ejection block, the spring force of the resilient arrangement on the can lid is exerted from above and with the lifting element of the same size Counterforce on the can body is exercised from below. Folding arrangement according to one of claims 1 to 9, wherein in combination with claim 2 between the holding element and the ejection rod or in combination with claim 3 between the holding element and the fastening element at least one spring, in particular at least one coil spring or an elastomer spring or a leg spring is provided , Folding arrangement according to one of claims 1 to 10, wherein the spring force of the resilient arrangement of the holding element is between 10 and 50 N. and / or wherein a spring travel of the resiliently arranged holding element is between 0.2 and 2.0 mm. Folding arrangement according to one of claims 1 to 11, further comprising at least one folding roller, in particular two folding rollers. Folding device, comprising: a carousel with a plurality of folding arrangements according to one of claims 1 to 12; a first inlet for can bodies, in particular can bodies filled with a product, to the carousel; a second inlet for can lid to the carousel; and a spout for folded cans from the carousel. A method of folding a can lid to a can body comprising the steps of: Feeding the can lid and the can body to a folding arrangement of a folding device; Positioning the can lid on the can body; Positioning the can body on a lifting element; Exerting a spring force on the can lid with a resiliently arranged holding element of an ejection block movable relative to a chuck in an axial direction of the chuck; Folding the can lid to the can body by means of at least one folding roller, in particular with two folding rollers, and the folded chuck; synchronous lowering of the ejection block and the lifting element while maintaining the spring force on the can lid; Lifting the ejector block from the can lid; and Discharging the folded can from the folder. Use of a folding arrangement according to one of claims 1 to 12 for folding a can lid to a can body.

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