EP0414081B1 - Method and device for filling and closing cans - Google Patents

Description

The invention relates to a method according to the preamble of claim 1 and a device according to the preamble of claim 4.

Filling cans with a liquid, such as a still or carbonated drink, is done in a can filler to which the cans are fed in a row. The liquid is filled from a supply into the cans by means of filling heads, which are then conveyed on to a closing unit, where they are closed with a lid. In this way, still liquids are treated as well as liquids containing CO₂, such as lemonades or beer. The conveyor section between the can filler and the sealing unit is particularly critical, as it can be very long, especially in systems with high performance, and can therefore cause malfunctions and loss of quality due to foaming or spilling liquid. If the system is interrupted, the filled cans may remain unsealed in the conveyor line for a long time, which can also lead to a deterioration in the quality of the filled liquid due to foaming and access to atmospheric oxygen. There is therefore a desire to make this conveyor route as short as possible, but this is only possible to a limited extent for design reasons.

In order to prevent or limit the spilling of the liquid in the filled containers due to changes in speed or by shaking on the conveying path between the filler and the capper, it is known from US-A 3,314,519 known to put a lid on the filled container soon after filling. This happens in the conveyor line connecting the filler to the capper after the filled containers have left the filler. The lids are only loosely placed on the opening of the container and are only pressed on and tightly closed in the capper. This procedure is not very suitable for the transfer of carbonated liquids under pressure because a pressure developing inside the container lifts the lid before the container has reached the capper. In addition, the filled containers on the conveying path section from the filler to the placement of the lids are open and accessible to the atmosphere with the consequences described above.

The invention is based on the object of specifying a further method and a further device of the type described at the outset, with which the spilling and foaming of the liquid filled into the cans is avoided even at high production speeds and the air access to the liquid is largely prevented.

This object is achieved according to the invention in a method of the type mentioned at the outset in that the lids are axially offset from the cans and introduced into a section of the can web which the cans in the filling device has filled after and are placed on the filled cans in this can web section and the lids are pressed onto the can opening with a predetermined force on the way from the filling device into the closing device.

In a device of the type specified in the introduction, the object is achieved in that the cover feed has a cover conveyor which conveys the covers along a cover path, that the cover path overlaps the path of movement of the filled cans in a union zone lying in the can filler, that means for placing the covers on the filled cans in the merging zone and means for holding down the lids placed on the filled cans are provided at least during the conveying of the cans in the transfer direction from the can filler to the closing device.

Features of independently inventive developments and advantageous and expedient refinements of the invention are contained in the subclaims.

According to the invention, the filled cans are covered immediately after filling, so that the oxygen access is interrupted long before the actual sealing. Particularly favorable conditions result from the invention, because the lid is placed in the can filler immediately after the filling process has ended. As a result, the time of air access to the filled liquid is kept extremely short, which prevents negative effects on the quality of the liquid in the cans and means a largely aseptic treatment of the liquid. By holding the lid down on the filled cans with a correspondingly predetermined force, the foaming of the liquid on the way to the closing device is largely suppressed, so that malfunctions with longer downtimes remain without any significant negative consequences for the quality of the can filling. The filled cans can be straight from the can filler to Closing device are promoted, although longer conveying routes can be tolerated because the cans are covered early. However, the embodiments of the invention are regarded as particularly advantageous according to which the filled cans are conveyed along a curved path from the can filler to the closing device. This is preferably achieved with the features of the claims which relate to the design of the lid conveyor as a circular conveyor. Even with a high conveying capacity, that is to say at a high web speed of the filled cans between the can filler and the closing device, leakage or spillage of the liquid is reliably ruled out because of the covers placed on them. In addition, this measure has the advantage that the curved guidance of the conveyor track between the can filler and the closing device results in a short conveying path, which enables the units to be assigned to one another in a compact manner.

The circular design of the lid conveyor also means that the lids have short feed paths to the union zone in the can filler. The design of the lid conveyor is also considered to be particularly successful in terms of design and function, as a can conveyor to the closing device, the filled cans conveying the lid into the closing device. This multiple function of the lid conveyor results in a structurally compact, functionally sensible and reliable and economically efficient solution to the problem of closing the filled cans.

The radial mobility of the lid receptacles of the lid conveyor allows the union zone between the filling device and the lid conveyor to be extended upstream from the discharge end of the can path of the filler. This stands for hanging up the A longer conveyor path section is available on the cans in the union zone, which benefits the process of placing the lid on. The inclined support surfaces in the can receptacles of the lid conveyor cause the cans to be lifted slightly when they are transferred to the lid conveyor and lifted from the can carrier of the filler. This results in extensive freedom from friction at the bottom of the can. The filled cans are held securely in the can holders with suction air. The suction air and the support surfaces also allow the lids to be pressed on without the cans being tipped out of the receptacles or being pressed downwards. This ensures that the cans are transported safely from the filler to the capper without damaging the can or losing liquid from the can.

The arrangement proposed according to the invention of all units of the device on a common machine bed enables a modular construction which allows the combination of several such devices to form large high-performance filling plants, each module itself being optimally designed with regard to can throughput and filler dimensions. By combining several modules with an optimal performance / dimension ratio, high-performance filling systems can be put together whose space requirements are far below that of a single filling device with the same performance. It is therefore advantageous to distribute the filling capacity over several such optimally designed modules when a high filling capacity is required, instead of providing a single filling device with a correspondingly large capacity, which depends on the capacity and therefore on the number of filling elements Dimensions have disproportionate spatial dimensions. The distribution of a required large filling performance over several modules with an optimal performance / dimension ratio requires the same Overall performance requires less space. In addition, power reserves can be kept readily available in the form of such filling modules. In addition, such a filling system composed of modules can be easily adjusted to different power requirements by switching individual modules on or off. Another advantage of the modular design is that each module can be encapsulated from the environment with little effort, which reduces environmental influences on the filling process and the quality of the liquid in the open cans and reduces noise pollution in the environment.

Fig. 1

ein Ausführungsbeispiel der Erfindung in einer perspektivischen Ansicht,

Fig. 2

eine Draufsicht auf die für das Verständnis der Erfindung wesentlichen Teile der Vorrichtung nach der Fig. 1 in schematischer Darstellung,

Fig. 3

einen Schnitt durch die Vorrichtung nach der Erfindung entlang der Linie III-III in Fig. 2,

Fig. 4

die Darstellung einer Einzelheit der Vorrichtung nach der Fig. 2 in einem Schnitt entlang der Linie IV-IV,

Fig. 5

eine weitere Einzelheit der Vorrichtung nach Fig. 2 in der Ansicht in Richtung des Pfeiles V in Fig. 2 und

Fig. 6

eine abgewandelte Ausführungsform der Erfindung in vereinfachter schematischer Draufsicht.

The invention will now be explained in more detail with reference to the drawing. Show it:

Fig. 1

an embodiment of the invention in a perspective view,

Fig. 2

2 shows a plan view of the parts of the device according to FIG. 1 which are essential for understanding the invention, in a schematic illustration,

Fig. 3

3 shows a section through the device according to the invention along the line III-III in FIG. 2,

Fig. 4

2 shows a detail of the device according to FIG. 2 in a section along the line IV-IV,

Fig. 5

a further detail of the device of FIG. 2 in the view in the direction of arrow V in Fig. 2 and

Fig. 6

a modified embodiment of the invention in a simplified schematic plan view.

In Fig. 1 an embodiment of a device for filling liquids into cans, in particular for filling a CO₂-containing liquid under pressure according to the invention is shown in perspective. This device consists of a can filler 1, a closing device 2, a lid feed 3 and can conveying means 4 and 6 for feeding in and out the empty and the filled cans 7, 8 and. The can filler 1 has, in a known manner, an annular bowl 9 which rotates in the direction of the arrow 9a and which contains the liquid to be filled supplied via the connecting lines 9b. The ring bowl is rotatably mounted on a central base 10. The feeds of the liquid to be filled and the gas also run in the base 10. Both are not the subject of the invention and are therefore not shown. The empty cans 7 are successively transferred individually by means of a screw conveyor 4a and a feed star 4b into the can receptacles 11 of the can filler, which are schematically indicated in FIG. 1 as a carrier ring. The can receptacles 11 are assigned in the circumferential direction side by side axially aligned filling elements 12, the structure and function of which, like that of the can filler itself, are known per se and therefore do not require any further description here. Such a filling element is described, for example, in German patent application P 39 28 009.8 from August 24, 1989 by the applicant. To fill the cans 7 with a carbonated, pressurized liquid, the cans are first pretensioned by applying pressure in the peripheral section A after placing the respective filling head 12, then filled in the peripheral section B and finally relieved of the pressure in the peripheral section C before they filled can be removed from the can filler. In the circumferential section D, metering containers which are possibly assigned to the filling elements and are not shown in the drawing can be filled for the next filling cycle.

The can conveyor 6 for conveying the filled and closed cans 8 has a conveyor star 6a and a conveyor section 6b.

The can filler 1, the closing device 2, the lid feed 3 and the can conveying means 4 and 6 and possibly other necessary units are arranged on a common machine bed 13 and surrounded by a common housing 14. A can filling and closing module 16 is thus designed, which can be optimized with regard to performance and dimensions and can be combined with other such modules 16a to form a filling system of any desired power, the ratio of power to dimensions to higher performance of the system compared to a single filling device of equally high performance is getting better.

FIG. 2 shows the parts of the device shown in FIG. 1 necessary for understanding the invention in a plan view of a section along the line II-II of FIG. 3.

In Fig. 2 it can be seen that the lid feeder 3 has a lid store 17 for holding a supply 17a of lids 18, a lid feeder 19 and a lid conveyor 21. The lid store 17 contains the lid supply 17a in the form of a stack of lids 18, which are removed individually by means of known separating means, not shown in the drawing, and taken over by the lid feeder 19 one after the other. The lid feeder has a curved guideway 19a for the lid 18 and a drive element 22 rotating in the direction of the arrow 22a, which moves the lid 18 from the store 17 to the lid conveyor 21 with drivers 22b engaging in the lid guideway 19a.

The cover conveyor 21 is designed as a circular conveyor which has drivers 21a on its circumference at a predetermined distance from one another. With the drivers 21a, the lid conveyor 21 engages from below in a guide track 21b which connects essentially horizontally to the guide track 19a of the lid feeder 19 and leads the lid 18 to the can filler 1. The movement path of the lids predetermined by the guideway 21b overlaps the movement path of the filled cans 8 on the can filler 1 rotating in the direction of the arrow 1a in a union zone 23 in which the respective filling member 12 is lifted from the relevant can and the lids 18 successively onto successive cans 8 be put on. The lid 18 are introduced by the lid conveyor 21 approximately horizontally between the can opening and the filling element 12 just lifted into the union zone 23, so that each filled can 8 is covered with a lid 18 immediately after the filling process and the lifting of the filling element. The union zone 23 can extend over more than one division in the filler. This is achieved, for example, in that the cover web 21b in the illustration in FIG. 2 is guided radially away from the cover conveyor 21 to the filler 1 and in that the hold-down devices 24 of the cover conveyor 21 are correspondingly radially movable. This can take place, for example, in that the pressure levers 27, as indicated by dashed lines in FIG. 3, are mounted on a slide 51 which can be moved radially by means of a control cam 49. The extension of the union zone makes it easier and easier to put the lids on the filled cans. This course of the cover sheet is indicated in FIG. 2 by a dashed line 21c.

The lid conveyor 21 is provided on its circumference with can receptacles 24, into which the filled cans pass during the placement of the lid 18 in the union zone 23 and are conveyed to the closing device 2 together with the lids.

In order to hold the lid 18 on the cans during the movement to the closing device, hold-down devices 26 in the form of fork-shaped pressure levers 27 are provided in the embodiment shown in FIGS. 2 to 5, the fingers 27a of which press the lid onto the can opening in opposite edge sections. In this way, the lids are reliably held on the cans during transport into the closing device 2 and pressed so tightly that the foaming of the liquid and spillage during movement on the curved path are prevented even at high speed.

Each can receptacle 24 of the lid conveyor 21 is assigned a rotating pressure lever 27. Details of this arrangement can be found in FIG. 3, which represents a section along the line III-III of FIG. 2. According to this, the lid conveyor 21 is designed as a rotating conveyor star, which holds the filled cans 8 in the receptacles on its circumference. Each can receptacle 24 has an inclined support surface 52 at its lower edge. If a can 8 is pressed into the receptacle 24 during the transfer in the union zone, the inclined support surface 52 causes the can to be lifted slightly from its previous base 53 in the filler. This prevents the can base from being ground over the support 53 during the transfer. In its raised position in the can receptacle 24, the can 8 is held by suction air which is applied to the can receptacle via a suction air line 54. The suction air line is connected to a vacuum source 57 via a rotary connection 56. A valve 58 closes the suction air line 54 when there is no can in the receptacle. By pressing a can 8 by means of the counter pressure stops 59 in the filler during Transfer in the union zone, the valve 58 is opened so that the suction becomes effective. The suction through the suction air line 54 and the inclined support surface 52 prevent the can from being pressed down out of its receptacle under the pressing force of the hold-down device or pressure lever 27 or from tipping radially outward while it is being conveyed to the closer. The cover conveyor 21 is driven by a shaft 28 which is rotatably supported at the top in a stationary housing 29 and is driven by a drive (not shown). On the outside of the fixed housing part, a bearing point 29a is provided, at which a carrier disk 31 is axially offset from the cover conveyor 21 and rotatable synchronously with it. The carrier disk 31 carries the pressure levers 27 arranged in a star shape, which are pivoted axially to the cans 8 against the force of a compression spring 32. The movement of the pressure lever 27 axially to the cans is controlled by a control cam 33 which concentrically surrounds the shaft 28 and is carried by a star-shaped holder 34 attached to the housing 29. Each pressure lever 27 carries a freely rotatably mounted control roller 36 which rolls on the control cam when the cover conveyor and the carrier disk 31 rotate. The control cam 33 is designed and arranged in such a way that the pressure levers 27 in the union zone 23 are lowered onto the lid 18 and press it with the force of the spring 32 onto the can opening. Instead of the spring 32, other force elements are of course also conceivable. In the closing device 2, the pressure levers 27 are lifted again from the covers by the control cam 33 as soon as a counterpressure stamp, which is not shown in the drawing and has been known per se, has been lowered onto the covers and the cans with the covers have been delivered to the closing device, where they are closed, for example, by flanging the edge of the lid.

In Fig. 3, the filling member 12 is shown in its raised position which it occupies in the union zone 23.

FIG. 4 shows in detail a section along the line IV-IV of FIG. 2. The guideway 21b of the cover conveyor 21 can be seen there, on which a cover 18 is moved to the union zone. The pressure lever 27 is held here by the control cam at a distance above the lid. As shown in FIG. 4, the guideway is fastened to the holder 34, which also carries the control cam 33.

A further detail of the lid conveyor 21 is shown in a view in the direction of arrow V in FIG. 2 in FIG. 5. This figure shows the lid conveyor 21 with the drivers 21a and the can receptacles 24. Above the lid conveyor 21 there is the control cam 33, which the control rollers 36 the hold-down 26 leads. An upper control curve 37, which runs parallel to the control curve 33, causes the hold-down devices to be brought down to the lower control curve 33 even if the compression springs 32 should fail as a restoring force. This prevents the hold-down devices from running too high into the union zone 23 and colliding with the filling elements 12. The control curve 37 thus serves the operational safety of the device.

The carrier disk 31 is driven from the drive shaft 28 via gearwheels 39 and 41a, a transmission shaft 42 mounted in the housing and the gearwheels 41b and 38.

Fig. 6 shows a slightly modified embodiment of the invention in a simplified schematic plan view. It is essentially the same arrangement as in FIG. 2; the same reference numerals are therefore used for the same parts.

6 shows the cover store 17 on the left, from which the cover 18 is conveyed individually to the cover conveyor 21 by means of the cover feeder 19 along the guide path 19a indicated by two lines 43 and 43a. The cover conveyor 21 is basically constructed in the same way as that shown in FIGS. 2 to 5. In the exemplary embodiment in FIG. 6, however, the hold-down devices 26 are simultaneously designed as cover receptacles 44, which are provided with an additional radial possibility of movement. Each cover receptacle 44 has an approximately semicircular slot 46 which is adapted to the outer radius of the cover and into which a cover is inserted during the transfer from the cover feeder 19 and held during the further circulation. The cover guide 43 runs opposite the cover receptacles 44 and prevents the cover from falling out of its receptacles. The cover receptacles 44 can be moved radially in guides 48 by means of a control curve 47 and in height, that is to say axially to the axis of the cover conveyor 21, by means of a control curve 61 and control rollers 62. The radial movability of the lid receptacles 44 ensures that the union zone 23 in the can filler 1 extends upstream from the discharge end of the can path of the can filler. In this way, the union zone 23 can extend over more than one division, as a result of which more time is available for placing the lid 8 in the can filler.
The cans temporarily sealed with the lids are transferred to the can receptacles of the lid conveyor 21 at the discharge end of the can path of the filler 1, slightly raised and held with suction air (see FIG. 3) and conveyed to the closing device 2. The lid 8 with the lid receptacles are pressed onto the cans so that foaming and spilling of the liquid is reliably ruled out, even when working at high conveying speeds. A guide 63 running parallel to the conveying path of the cans prevents the cans from falling if there are any faults. In normal operation, the cans are held in the receptacles 24 with suction air or other suitable means and are not in contact with the guide 63.

Claims (16)

1. Method of filling cans with a liquid, in particular with a carbonated liquid under increased pressure, and of closing the filled cans with a lid, wherein a series of cans in a filling apparatus are conveyed along a predetermined can path and are successively filled with a predetermined quantity of the liquid, after the filling process a lid is placed onto each filled can, the filled cans with the lids placed on top are conveyed into the closing device and the cans are firmly closed with their respective lid in the closing device, characterized in that the lids are introduced axially offset relative to the cans into a section of the can path, which the cans in the filling apparatus run through after filling, and are placed onto the filled cans in said can path section and that the lids, as they travel from the filling apparatus into the closing device, are pressed down with a predetermined force onto the can opening.
2. Method according to claim 1, characterized in that the cans, after filling and placing of a lid on top, are conveyed along a curved path into the closing device.
3. Method according to claim 1 or 2, characterized in that the lids, prior to being placed on top of the cans, are fed along a curved path.
4. Apparatus for filling cans with a liquid, in particular with a carbonated liquid under increased pressure, and for closing the filled cans with a lid, having a can filler (1) which has means (11, 12) of conveying the cans (7) to be filled along a predetermined can path and filling organs (12), which are movable along a path which at least in sections corresponds to the can path, for filling cans (7) which are successively conveyed along the can path, a closing device (2), a transfer device (3) for conveying the filled cans from the can filler to the closing device and a lid feed device (3), characterized in that the lid feed (3) has a lid conveyor (21) which conveys the lids (18) along a lid path (21b), that the lid path overlaps the path of movement of the filled cans (8) in an assembly zone (23) situated in the can filler, that means (21, 21a, 21b) of placing the lids (18) onto the filled cans (8) in the assembly zone (23) and means (26) of holding down the lids (18) placed onto the filled cans (8) at least while the cans (8) are being conveyed in the transfer device (3) from the can filler (1) to the closing device (2) are provided.
5. Apparatus according to claim 4, characterized in that the lid conveyor (21) takes the form of a revolving conveyor having means (21a, 21b) of conveying lids (18) and having receivers (24) for taking over the filled cans (8) from the discharge end of the can path of the can filler (1) and that said lid conveyor simultaneously takes the form of a can conveyor which conveys the filled cans (8), together with the lids (18) placed on top, from the can filler (1) to the closing device (2).
6. Apparatus according to claim 4 or 5, characterized in that the assembly zone (23) for bringing together cans (8) and lids (18) extends along the can path upstream of the discharge end of the can path of the can filler (1).
7. Apparatus according to one of claims 4 to 6, characterized in that a stationary lid guideway (21b) aligned towards the assembly zone (23) is associated with the lid conveyor (21) and that the lid conveyor (21) has drivers (21a) which engage into the guideway (21b) and successively move the lids (18) one at a time along the guideway into the assembly zone (23).
8. Apparatus according to one of claims 4 to 6, characterized in that the lid conveyor (21) has axially movable lid receivers (44) and that control means (47) are provided, by means of which the lid receivers, after taking over a lid (18), are moved outwards with a predominantly radial component towards the filling apparatus (1) and upon axial overlapping with a can (8) are restored again according to the course of the can path.
9. Apparatus according to one of claims 4 to 8, characterized in that pressure levers (27), which press the lids (18) in each case with a predetermined force onto the cans (8), are provided as holding-down devices (26).
10. Apparatus according to claim 9, characterized in that the pressure levers (27) are of a fork-like construction and press the lids (18) onto the cans (8) by means of pressure fingers (27a) on the lid edge.
11. Apparatus according to one of claims 4 to 10, characterized in that the holding-down devices (26) are disposed on a carrier element (31) concentric with and axially offset relative to the lid conveyor (21) and rotate in synchronism with the lid conveyor, and that the holding-down devices are movable in a controlled manner axially relative to the cans (8).
12. Apparatus according to one of claims 4 to 11, characterized in that the can filler (1), the closing device (2), the transfer devices (4, 6) and the lid feed device (3) are disposed on a common machine base (13).
13. Apparatus according to one of claims 4 to 12, characterized in that each can receiver (24) of the lid conveyor (21) has controllable suction air feeds (54, 58) which are connected to a vacuum source (57).
14. Apparatus according to claim 13, characterized in that each can receiver (24) of the lid conveyor (21) has, approximately at the level of the can carrier (53) of the filling apparatus (1), a supporting surface (52) which engages under at least the rim of the can base.
15. Apparatus according to claim 14, characterized in that the supporting surface (52) extends in a downward sloping manner from the locating face of the can receiver (24).
16. Apparatus according to claim 14 or 15, characterized in that the supporting surface (52) lies at least in the region adjacent to the locating face of the can receiver (24) above the can carrier level of the filling apparatus in the assembly zone.

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