EP0241680B1 - Method and apparatus for closing containers - Google Patents

Abstract

The present invention relates to a method and an apparatus for closing containers with a cover foil. In the method and with the apparatus of the invention, the containers are conveyed without change in vertical position and without stopping between rotation systems bearing the closure tools and rotating above and below the plane of the conveyor belt, and provided with covers.

Description

The invention relates to a method for closing containers, in which the containers are conveyed on a feed conveyor one behind the other in a horizontal plane to a closing station, in which closing tools rotating periodically in a circular rotational movement move towards the containers and then the container with continuously continued movement be provided with a cover film.

The invention also relates to a device for closing containers with a lid film, with a conveyor belt, on which the containers are conveyed in a horizontal plane to the inlet side of a closing station, which comprises an upper, rotating closing tool carrier, which guides at least one closing tool in a circular path and periodically lowering the closing tool onto containers conveyed under the closing tool carrier for fastening the cover film.

A method and a device of this type is known, for example, from British patent specification 923 741. Closure systems of this type have the advantage over other systems, for example those described in DE-PS 29 13 026, that they work continuously, ie that in generic systems the containers do not have to be stopped in order to compress the cover film with the usual edge flanges of the containers perform.

These continuously operating capping systems not only have the advantage over the intermittently operating systems that larger capping capacities (containers per unit of time) are possible, but are also advantageous because the containers can be braked, which leads to the intermittently operating systems that generally complicated brake controls must be present, so that in particular liquid container contents do not spill over when braking.

There is therefore no risk of it spilling out with the continuous closure systems.

In continuous systems, as is shown in GB-PS 923 741, it is known to arrange a rotation system above the transport path on which the containers are conveyed to the closing station, which rotates around a number of closing tools in a rotational movement and closes the successively conveyed containers. The containers are loosely covered in front of the rotation system with a cover film cut at a cutting station, which is then molded onto the container by the tools in the rotation system. After the rotating tools have released the containers again, the conveyor belt conveys them further into a heat treatment zone, so that a seal takes place between the cover film and the container.

However, this known locking system is disadvantageous in many ways. A major disadvantage results from the fact that the containers to be closed pass on the conveyor belt at the uniform conveyor belt speed under the rotation system. In order to bring the conveyor belt container into engagement with the rotating tools, these are raised from their form-fitting receptacles in which they are conveyed on the conveyor belt by a cam-controlled lifting element and inserted into an incoming tool.

However, since the tool moves at a constantly changing horizontal speed due to the rotational movement, while the horizontal speed of the conveyor belt always remains constant, coordination problems arise when transferring the containers to the rotating closing tool and when reinserting them into the container holder on the conveyor belt. Although the rotation system can rotate at such a rotation speed that the horizontal speed of a closing tool corresponds to the conveyor belt speed when passing through the vertical speed zero point, this only achieves a speed adjustment over a very small range, so that the closing tool only over very small distances, in particular at relatively high throughputs can act on the container without causing excessive divergence between the container and the associated container receptacle in the conveyor belt.

Since the rotating tool can only work in a coordinated manner with the containers over short distances, the number of steps that can be carried out with it and required for closing is limited. Therefore, in this known system, the cover foils are previously placed in a separate station on the containers and the sealing is also carried out in a separate station in the transport direction behind the rotation system.

This known system is therefore unsuitable in particular if the lid film is to be fastened to the container by a crimp closure, for which purpose it is necessary to exert a high pressing pressure with the aid of precisely aligned upper and lower tools. The same applies to high quality sealed closures e.g. for sterilizable containers.

A closing device is known from FR-A 2 229 612, in which the containers to be closed are received between jaws which move horizontally with the containers on a belt through the closing station. The actual closing process takes place through the interaction of the horizontally moving clamping jaws and the upper tool during a horizontal guidance of the upper tool over a certain distance.

From US-A 3 850 780 it is known to work with devices for welding foils, for example for the production of plastic bags, with a circular upper and lower tool. However, in order to be able to adapt the rotational speed to the speed of the film web passed through, it is necessary that the rotational movement of the top and bottom Lower tool is controlled via a corresponding cam control.

The invention has for its object to improve the method and the device of the type mentioned in such a way that large total throughputs (containers per unit of time) can be reliably achieved with a small footprint and simple structure.

To achieve this object, the method mentioned at the outset is characterized in that the containers are transferred to a circularly rotating lower tool carrier when they enter the closing station for further transport and are aligned by the latter to the closing tool at a speed which corresponds to the respective horizontal speed of the rotating closing tool. can be transported through the locking station without changing the vertical position.

According to these features, the containers are conveyed through the closing station without vertical movement in a constant horizontal plane, which also corresponds to the transport plane, and at a speed which corresponds in each case to the horizontal speed component of the closing tools then acting on the container. Thus, the horizontal speed of the container as it passes through the closing station is adapted to the horizontal speed of the closing tool, and the closing tool can thus act on the container over a relatively long distance despite the rotary drive. This opens up the possibility of being able to carry out various process steps required depending on the desired type of closure at a single closing station and thus to save space. Because the containers are conveyed through the closing station without a vertical change in position and a continuous horizontal movement is thereby guaranteed, there is no danger that any filled liquids spill over during the passage through the sealing machine.

In a very advantageous development of the method it is provided that the containers are closed with the aid of upper and lower tool halves, which are periodically moved towards one another by upper and lower tool carriers rotating in circular paths and center the containers in a coupling phase, provided with a cover film, fold the lid around a container flange to produce a crimp closure and press it with the lid, the maximum closing pressure being generated when the vertical movement component of the rotational movement is zero. With these features, all the steps necessary for locking are carried out when the upper and lower tools are in full synchronization during the coupling phase. In the coupling phase, in particular all the steps necessary for a firm crimp closure can be carried out, including pressing. The interaction of upper and lower tools in connection with two rotating upper and lower tool carriers also has the advantage that "soft" movements are achieved for the tool halves, which counteracts tool wear. The stacking of the tool halves in a circular motion further enables the containers to be closed in a flowing, shock-free process. Since the correct interaction of the upper and lower tools can always be guaranteed in the coupling phase when the two rotation systems run in sync, it is possible to operate at different, freely selectable speeds and thus different flow rates.

A device of the type mentioned achieves this task in that the closing station comprises a lower, rotating tool carrier, which has at least one container carrier (as a tool), which is periodically guided by the tool carrier on the inlet side into the conveyor belt level and that a positive guide for the When reaching the conveyor belt level, the container carrier is provided relative to the tool carrier in such a way that the container carrier moves through the closing station in this plane with the respective horizontal speed of the tool carrier at the attachment location of the container carrier without vertical change in position with respect to the conveyor belt plane, and that the upper closing tool carrier and the lower tool carrier move with the same Rotate speed of rotation and have their axes on a common vertical plane.

Characterized in that a lower rotating tool holder is assigned to the upper rotating capping tool carrier, which takes over the transport of the containers through the sealing station thus formed with the container carrier assigned to it, the conveying speed of the containers in the horizontal direction is controlled so that it corresponds to the horizontal speed component of the rotating Tool carrier corresponds. There is therefore no horizontal relative speed between the container and the closing tools. This synchronous speed is essentially achieved by the horizontal positive guidance of the container carrier plate attached to the rotating tool carrier, which takes over the containers from the conveyor belt. The container is thus conveyed from this plate through the closing station without any vertical change in position.

A further development of the invention provides that the upper closing tool carrier and the lower tool carrier each have two double-armed rotating vanes, between each of which traverses, on each of which a closing tool or a container carrier is fastened. This configuration of the upper and lower tool carriers creates light, simply constructed rotation systems. The rotary blades are advantageously driven via central shafts, and the crossbeams are mounted in the rotary blades and a synchronous planetary gear system is arranged between the central shafts and the crossbeams. The synchronous planetary gear system causes the crossbeams to move them on them, despite the rotational movement of the rotating blades Always keep tools or container carriers in a horizontal orientation.

A further embodiment of the invention provides that the container carrier is designed as a support plate which is held at a vertical distance from the associated cross member via a guide pin and a spring supported on the cross member, the guide pin extending through a vertical bore in the cross member and ends in a truss plate. The container carrier arrives relatively early in the transport path plane through a distance to the truss plate brought about by the guide pin and takes over the conveyed containers, so that the coordination of the horizontal speed of the container and closing tools takes place over a relatively large distance. This configuration also opens up the possibility of simply carrying out the horizontal guidance of the support plate by bringing the cross-member plate into contact with a horizontally extending, stationary guide rail. In a very advantageous further development of the invention it is provided that upper parts of the closing tool carrier and upper parts of the closing tool holder are fastened, which periodically move towards one another due to the rotation of their carriers and work together in a coupling phase for fastening the cover film.

The lower parts of the closing tool are advantageously arranged on the crossbars concentrically to the support plate, so that they can easily grip and process the containers placed on the support plates. The closing tool lower parts can comprise a pressure frame and a centering basket. Print frame and centering basket can be formed in one piece. As an alternative to this, the centering cage can also be mounted so as to be vertically displaceable relative to the printing frame. The centering basket primarily serves for the exact alignment of the container located on the support plate and, together with the pressure frame during pressing, forms the counter-pressure bearing when the two tool halves in the bearing closest to the traverses press the container edge with the foil with their tool-mating surfaces.

The vertical movement of the centering basket with respect to the printing frame can be controlled via a cam roller running in a guide groove. The centering basket can thus also be used in the manufacture of crimp closures by a suitable design of the guide groove even when the cover film folded around the edge flange of a container is formed.

The guide groove is advantageously introduced into a fixed cam strip, the horizontally running lower edge of which forms the guide rail for the support plates. The cam bar thus takes over both the control of the centering cage and the control of the support plate. If the curve bar extends symmetrically to the vertical center plane on both sides by half a radius of the rotating wing, this gives the possibility of controlling the support plate and the movements of the centering basket over a correspondingly large conveying path, so that the necessary work processes such as Centering, flanging and pressing the lid can be carried out.

A further embodiment in this context provides that the cam strip is designed as part of a standing hollow shaft mounted on the central shaft between the rotating blades. The standstill of the hollow shaft can be achieved, for example, in that the hollow shaft is connected to an inner sun gear which is held at a standstill via inner planet gears, which are driven by common planetary shafts with outer planet gears rotating around the outer sun gear belonging to the synchronous planetary gear. In this way, it is easily possible to keep the guide rail between the rotating blades at a standstill without having to provide a fixed connection to the housing, which would be difficult to attach without obstructing the cross-member rotations.

A further embodiment of the invention provides a locking device which prevents a sudden acceleration of the rotary wing after passing through the vertical central plane by relief forces. The locking device balances play and load for the upper and lower tool carriers. The locking device can be designed in the manner of a snap-in thrust bearing. This is achieved, for example, in that the locking device 'on the periphery of the rotating wing of the lower tool carrier has opposing engagement rollers and a locking disk of smaller diameter than the rotating wing, the axis of which lies with the axis of the rotating wing in a common vertical central plane which offset two by 180 _° Has recesses for receiving the engagement rollers and which is driven in the opposite direction to the rotary blades with a gear ratio with the same peripheral speed as the rotary blades. In addition, recesses can be made in the periphery of the rotary wing of the upper tool carrier, into which recesses the engagement rollers of the rotary wing of the lower tool carrier likewise engage.

In a further embodiment of the invention, an intermediate transport device is provided which takes over the containers from the conveyor belt by means of transport drivers which run around a chain and point transversely to the transport direction, and pushes transitional curves extending in the transport plane onto the container carriers which are guided horizontally in the transport plane. After the containers have been transferred to the container carriers, the transport drivers are preferably pivoted backwards away from the containers by means of a roller cam control in the transport plane. The transport drivers can be swiveled back into the transport path by a roller / curve control behind the then closed containers and thus push the containers from the container carriers over transition skids onto a conveyor belt. It was designed like this tated intermediate transport system, the continuous transfer of the containers onto the container carriers promotes the removal to a subsequent conveyor belt.

In a further embodiment of the invention, the sealing tool upper parts are designed such that they each place the lid foils on the containers and, in cooperation with the tool lower parts, produce a crimp closure, the sealing tool upper part itself having known slides which, in a closing movement, the lid foil under the edge flange of the container wrinkles. The movement of the slide is advantageously carried out using the relative movement between the cross members and the rotating wings of the closing tool carrier. For this purpose, control cams can be attached to at least one of the two rotary wings, which act on rollers, pendulum arms and coupling rods on a control disc arranged on the crossmember, which transmit their pivoting movement via tabs to the slide.

Finally, another embodiment of the invention provides that the upper and lower parts of the closing tool are designed as tools with which the cover film is attached to the containers to form a sealing closure.

• Figur 1 zeigt die Seitenansicht der Gesamtvorrichtung,
• Figur 2 eine Seitenansicht des unteren Werkzeugträgers,
• Figur 3 einen Schnitt entlang der Linie 111-111 der Figur 2, bei einer Position des Behälterträgers in der Mittelebene ME,
• Figur 4 einen Querschnitt durch den unteren und oberen Werkzeugträger und die Sperrscheibe,
• Figur 5 einen Querschnitt durch die oberen und unteren Verschließwerkzeughälften,
• Figur 6 eine Draufsicht auf die Verschließwerkzeuge,
• Figur 7 eine Seitenansicht des Antriebsschemas der rotierenden Werkzeugträger des Transportbandes und der Sperreinrichtung,
• Figur 8 eine Draufsicht auf das Behältertransportsystem und
• Figur 9 einen Querschnitt durch die Übergangskufen und den Zwischentransport.

The invention is further explained and described below with reference to an embodiment shown in the drawing for a conveyor closing machine working with upper and lower tools.

• FIG. 1 shows the side view of the overall device,
• FIG. 2 shows a side view of the lower tool carrier,
• FIG. 3 shows a section along the line 111-111 of FIG. 2, with the container carrier in a position in the central plane ME,
• FIG. 4 shows a cross section through the lower and upper tool carriers and the locking disk,
• FIG. 5 shows a cross section through the upper and lower halves of the closing tool,
• FIG. 6 shows a top view of the closing tools,
• FIG. 7 shows a side view of the drive diagram of the rotating tool carriers of the conveyor belt and the locking device,
• Figure 8 is a plan view of the container transport system and
• Figure 9 shows a cross section through the transition skids and the intermediate transport.

A device according to the invention is shown in an overall view in FIG. Columns 11 are attached to a machine frame 1, on which the central shafts 2 and 3 of a lower and upper tool carrier 4, 5 are mounted in a common vertical center plane. The tool carriers are also referred to below as rotation systems.

The rotation systems 4 and 5 have rotating vanes 410 and 510, each driven at a constant rotational speed, about the central shafts 2 and 3, between which traverses 210, 220 and 310, 320 extend. The traverses serve as carriers for the closing tool parts 211, 221 and 311, 321, which rotate periodically therewith. These tool parts are periodically moved towards one another during the rotating movement of the rotation systems 4 and 5 and act via a coupling phase for closing the containers conveyed between the closing station thus formed together.

The upper rotation system 5 is supplied with a cover film from a cover film supply roll 7 in a manner not to be explained in more detail here, and is then carried on to the containers by the upper closing tool parts 311, 321.

The sectional side view of FIG. 2 shows the structure of the lower rotation system in detail. The rotary wing 410 is driven around the central shaft 2 in the arrow direction P _R at a constant rotational speed. The crossbeam 210 is mounted in the rotary wing (the crossbar with lower tool parts, which is formed in an identical manner on the other rotary wing arm, is not shown for reasons of clarity). The traverse is positively guided with the help of a synchronous planetary gear system so that the traverse surface T _o remains horizontally aligned during the entire revolution. The lower tool, designated as a whole by 430, is attached to the crossmember. In the exemplary embodiment shown, the lower tool consists of a pressure frame 456, a centering cage 450 which is guided so as to be vertically displaceable relative to the pressure frame, and the support plate 431 for the containers B. The support plate is connected to a guide pin 432. The guide pin extends through the centering cage 450, the pressure frame 455 and a bore 442 of the cross member and ends in a cross member plate 433. The container support plate 431 is supported on the cross member by means of the counter bearing 444 via a spring 443.

A guide bar 434, which extends symmetrically to the center plane ME on both sides and is attached in a fixed position between the rotating wings, carries the guide bar 434 along with a cam bar 435 with a guide groove 455 to be explained in more detail, with the lower edge of the crossbar plate 433 for positive guidance of the support plate 431 in the horizontal plane HE cooperates.

As can be seen in connection with FIGS. 3 and 4, the cam strip 435 is carried by a standing hollow shaft 201, which is mounted on the rotating central shaft 2 between the rotating vanes 410 and 420. In order to keep the hollow shaft 201 stationary and thus the cam bar 435 stationary, a flange plate 13 is attached to the column 11 of the machine frame 1 via an anchor bolt 12 (see FIG. 4), to which the outer sun gear 436 of the synchronous planetary gear is screwed.

This sun gear is supported on the central shaft 2 via a bearing 437. It becomes via the outer stationary sun gear 436 and the outer planet gears 438 rotating around this sun gear and with these planet gears on common planet shafts 439 inner planet gears 441 is sufficient for an inner sun gear 440 to stand still. The hollow shaft 201, which in turn carries the cam strip 435, is fastened to this.

The guide groove 455 already mentioned is also introduced on the cam strip 435. With this guide groove 455, cam rollers 454, which are attached to centering basket guide columns 453, work together. The guide groove 455 extends, like the guide bar 434 for the crossbar plates 433, far behind the vertical central plane ME of the rotation systems 4 and 5 and thus causes the centering cage to make the corresponding lifting and lowering movements relative to the central shaft necessary for the closing process. Details of the upper rotation system are explained below with reference to FIGS. 5 and 6. The closure system shown here is used to close the containers that are being conveyed using crimp closures. The two upper tools 311, 321 (cf. FIG. 1) are rotatably mounted on their cross members 310, 320, but are likewise held in their horizontal position during the rotation of the system via the synchronous planetary gear (cf. FIG. 4). For the production of crimp closures, it is known per se to work with sliders 334, which fold over a cover film part projecting downward over the edge flange of the containers onto the container wall. For this folding process of the cover film under the edge flange of the container, the slide must carry out a closing movement. To control the slide, use is made of the fact that the crossbeams are always held in a horizontal position during the rotation of the overall system, while the rotary blades 510 and 520 rotate about the central shaft 3 of the upper tool. This creates a relative movement between the horizontal crossbeams and the rotating blades. In order to utilize this relative movement to the slide control, swivel plates 331 are arranged on the cross members 310, 320, which transmit the oscillating swivel movement generated via form-fitting central central bolts 332 to the slide 334 via tabs 333. The slides are guided in guides 335 and guide pins 336. The slip frame 337 also assumes a management function. This slip frame is fixedly mounted on the upper plate 338 of the upper tool. The top plate is spring-loaded and supported on the crossbar. The slip frame forms, together with the support skids 339, the support guides 322 for a cover film section 730, with which the upper tool has been loaded. The support runners 339 could also be attached directly to the spacers 340 so that the slip frame could then be dispensed with.

The lid film guide could then be taken over by sliders 334 with a stronger design in connection with the carrying skids 339.

The swivel movement for generating the slide movement is transmitted to the swivel plates 331 via coupling rods 341. This movement is generated by control cams 342, 343 attached to the rotary wings 510 and / or 520, which drive the coupling rods via rollers 344 and pendulum arms 345. It would also be possible to perform the forced control of the slide movement only in one direction, the movement in the other direction then e.g. could be done with the help of springs.

To generate the necessary closing pressure, we press the pressure frame of the lower tool half together with the pressure plate 338 of the upper tool half, the greatest pressure being generated when the two tools pass through the vertical center plane ME of the rotation systems. The springs, by means of which the pressure plate of the upper tool is supported in the traverse, are compressed. Since other compression and tension springs of the rotation systems have their highest tension in this position, means are provided which prevent the upper and / or lower rotation system from jumping when these springs are relieved after the center plane ME has been exceeded. These means are explained further below with reference to FIGS. 4 and 7. In these figures it can be seen that a locking disc 460 is arranged below the lower rotation system 4 on the same vertical central plane ME, on which the central shafts of the rotation systems are also located, which rotates counter to the lower rotation system and has a smaller diameter than the rotation systems . In this locking disk 460, two recesses 462 offset by 180 ° are provided for receiving engagement rollers 461 located on the rotary wings 410 and / or 420. These engagement rollers engage in the recess 462 in a form-fitting manner every 180 _° rotation of the rotary blades. The step-by-step acceleration of the rotary systems when the pressure is released from the closing pressure is weakened by a translation, in that the rotating blades follow the rotational movement of the locking disk. A gear ratio ensures the same circumferential speed of the smaller locking disk to the larger rotating blades. The engaging rollers 461 located opposite one another on the periphery of the lower rotary wings 410, 420 engage on the one hand in the locking disk 460 and also in recesses on the periphery of the upper rotary wings 510, 520. This also brings about a play compensation of the drive elements of the upper and lower rotary systems during the Engagement of the opposing tool halves with each other.

From FIG. 7 in particular, it can also be seen that the main drive 15 of the rotation systems is also connected to the conveyor belt drive shaft, so that the rotational movements of the rotation systems are coordinated with the movement of the conveyor belt 601.

The container transport is explained in detail below in connection with FIGS. 8 and 9. The containers are conveyed on the conveyor belt 601 from left to right, as in FIG. 8, to the closing station formed by the rotation systems 4 and 5. The conveying at suitable intervals is ensured with the aid of conveyor belt drivers 602 fastened on the conveyor belt. The transfer from the conveyor belt 601 and the conveyor belt drivers 602 on the support plate 431 of the lower rotation system is done with the aid of an intermediate transport system 650. This intermediate transport system comprises drivers 651 which can be pivoted into the transport path of the containers from the side. The drivers 651 are fastened to driver carriers 653, which in turn are held on a double chain link of a single roller chain 655 running in guides 654. The drivers 651 are pivotably articulated with respect to the driver carriers. In addition, thrust rollers 656 are connected to the carrier carriers, which cooperate with cam bars 657 during the container transport. The catches 651 take over the containers from the conveyor belt catches 602 before they move out of the movement downward around the drive shaft 6 and push them over the transition skids 603 onto the support plate 431 attached, which allow the support plate 431 in the conveying direction in the horizontal transport plane to overlap with the transition skids 603 by a certain distance. Accordingly, the support plate can then convey the containers on the discharge side in a soft movement onto the transition skids 604 provided there. While the carrier plate takes over the transport of the container between the rotation system, the drivers 651 fold back (652) in a controlled manner by the thrust rollers (656) rolling along the cam strips 657 and are transported further in this position by the chain 655. Folding back the drivers ensures that they do not hinder the closing process when the closing tool halves interact. It is sufficient to fold the drivers back from their straight position by approx. 30 _° because the drivers run through the closing station at approximately the same speed as the container. On the discharge side, the thrust rollers 656 act on a control cam 658, which has the consequence that the drivers now again assume their position pointing transversely to the transport direction. The drivers then push the container over the transition skids 604 onto a discharge belt 670. The intermediate transport elements are then circulated on the chain through the machine frame 1 back to the inlet side.

The device now works by performing the method as follows:

A container abutting the carriers 602 on the conveyor belt 601 is pushed at the end of the conveyor belt via stationary transition runners 603 onto the support plate 431, which in the vertical direction precedes the lower tool 430, first by the length of the guide bolt 432. The lower rotation system 4 has reached the position shown in Figure 1. While the conveyor belt 601 is now deflected around the conveyor belt drive shaft 6, the conveyor belt drivers 602, which also run downward, push the container over the transition skids 603 in the direction of the support plate 431. The containers are gripped by the intermediate transport drivers 651 without stopping and continue via the transition skids onto the Support plate 431 pushed, the vertical movement of which has just been stopped by the stop of the cross plate 433 on the guide bar 434 and which now only moves horizontally, being accelerated to the summit point of the circular path 223 of the lower rotation system due to the increasing horizontal speed component of the rotational movement of the system, and then in same delay in this component. If the rotary movement is now continued from the position shown in FIG. 1, the lower tool (centering basket and pressure frame) moves up further from the position shown. After passing through a certain angle of rotation, the centering basket 450 takes over and centers the container B standing on the support plate with the aid of its inner wall 451. The inner container receptacle of the centering basket is expediently designed in coordination with the dimensions of the container B so that the upper edge 452 of the centering basket 450 up to below the horizontal edge flange BR of the container, with a slight (1 to 2 mm) lifting of the container for absolutely central centering of the same on the support plate 431 being possible. After centering, the centering basket is not moved higher with the help of the guide groove 455, but lowered again to make room for the lid edge which has now been put over the container edge flange by the upper tool. This edge of the lid is folded vertically downwards in a first phase and is then pushed under the container edge flange in a second phase with the aid of the sliders and partially brought up to the outer wall of the container which tapers downwards. Then the centering basket is raised again by control via the groove 455 in the direction of the container edge. During these processes, the rotation systems increasingly approach the position in which the traverses of the tool halves that are moving toward one another pass through the point of maximum approach (summit point 223 of the circular path). During this approach movement, the pressure frame 456 fastened on the cross member 210 is moved ever further upwards for pressing on the lid edge bent under the edge flange of the container. The final sealing pressure is achieved in cooperation with the pressure plate 338 of the upper tool with the pressure frame 456 when the upper and lower parts of the closing tool are located on the vertical central plane ME of the rotation systems.

The container, which is now provided with a crimp closure, is then conveyed to the discharge side, this further conveying moving further in the horizontal plane HE owing to the forced guidance of the container support plate 431 and the centering basket 450. When the tools run apart, the locking disc and the engagement rollers prevent the rotation systems from jumping.

In the meantime, the drivers of the intermediate transport system are also in their pivoted position ge has been moved across the central plane ME. In the further movement, the support plate moves further horizontally, however, while the lower tool 430 dips downward on the crossmember, the horizontal component of the rotational speed becoming smaller and smaller. The drivers 651 now take over the container from the slowing support plate and push it further over the discharge runners 604 onto a discharge belt 670, while the transport plate then also dips. In the meantime, the complementarily arranged second lower tool emerges from below in the inlet area 600 of the containers and the processes run again in coordination with the second upper tool in the manner described. Since the motion sequences of the rotation systems, the transport systems and the closing tools are mechanically coupled, the speed at which the device works can be freely selected in a simple manner. The soft, alternating horizontal and vertical components of the movement sequences mean that the tools are not very susceptible even at high working speeds of the entire system. In contrast to stationary systems with a purely linear movement, the tool halves in the invention are not subject to wear as a result of violent, sudden closing movements. The air pockets between the container / lid / tool that frequently occur during fast closing movements and lead to bombing of the packaging are also avoided. All steps necessary for closing a container, including the placement of prefabricated or molded cover foils, can be carried out at one station due to the coordination of the conveying movement of the containers and the rotating tools, so that the overall device is very space-saving overall.

The described method and the device are suitable both for the manufacture of flared and sealed closures by using appropriate tools. Containers with a vertically upright sealing edge and with insert lids can also be closed according to the method of the device with a corresponding modification of the tools. In addition to the different types of tools used, the device can also be modified such that the crossbeams are not supported on both sides on rotating sashes with continuous axes, but only one-sided mounting is provided on only one rotating sash. Of course, you can also work with more than two tool units per rotation system.

Claims (28)

1. A method of closing containers, in which the containers are fed to a closing station on a feed conveyor disposed one after the other in a horizontal plane, in which closing station closing tools periodically rotating in a circular rotary movement move towards the containers and the containers are then closed with a lid foil as they continually move forward, characterised in that on entry into the closing station the containers are transferred for further transport to a rotating bottom tool carrier (4) and, aligned by the latter, are transported through the closing station without any change of vertical position to the closing tool at a speed corresponding to the horizontal speed of the rotation closing tool at any time.

2. A method according to claim 1, characterised in that the containers are closed by means of top and bottom tool halves which are periodically moved towards one another by top and bottom tool carriers rotating in circular paths, which top and bottom tool halves in a coupling phase centre the containers, provide them with a lid foil, fold the lid, in order to make a flanged closure, around an edge flange of the container and press it to the lid, the maximum closing pressure being generated when the vertical component of the rotary movement is zero.

3. Apparatus for closing containers with a lid foil, comprising a conveyor belt on which the containers are fed in a horizontal plane to the entry side of a closing station, which comprises a top rotating closing tool carrier (5) which guides at least one closing tool in a circular path and periodically lowers the closing tool on to containers fed beneath the closing tool carrier in order to fix the lid foil, characterised in that the closing station (4, 5) comprises a bottom rotating tool carrier (4) having at least one container carrier (431) (as a tool) which is periodically guided by the tool carrier (4) on the entry side into the plane of the conveyor belt and in that a positive guide (433, 434) is so provided for the cotnainer carrier (431) on reaching the conveyor belt plane (HE) opposite the tool carrier that the container carrier (431) moves through the closing station (4, 5) without any change of vertical position with respect to the conveyor belt plane (HE) in said plane at the horizontal speed of the tool carrier (4) at any time at the fixing place (210, 220) of the container carrier and in that the top closing tool carrier (5) and the bottom tool carrier (4) rotate at the same speed of rotation and have their axes (2, 3) on a common vertical plane (ME).

4. Apparatus according to claim 3, characterised in that the top closing tool carrier (5) and the bottom tool carrier (4) each comprise two double-armed rotary blades (510, 520; 410, 420), between each of which exgend cross-members (210, 220, 310,320) on each of which a closing tool (311, 321) and/or a container carrier (431) are secured.

5. Apparatus according to claim 4, characterised in that the rotary blades (510, 520; 410, 420) are driven via central shafts (3, 2), in that the cross-members (210, 220; 310, 320) are mountd in the rotary blades and in that a synchronous planetary gear system (230) is disposed between the central shafts and the cross-members.

6. Apparatus according to claim 4 or 5, characterised in that the container carrier is constructed in the form of a carrier plate (431) held via a guide bolt (432) and a spring (443) supported on the cross-member (210, 220) at a vertical distance from the associated cross-member, the guide bolt (432) extending through a vertical bore (442) in the cross-member and terminating in a cross-member plate (433).

7. Apparatus according to claim 6, characterised in that for horizontal positive guidance the cross-member plate (433) is moved in abutment with a horizontally extending stationary guide rail (434).

8. Apparatus according to at least one of claims 3 to 7, characterised in that closing tool top parts (334, 337, 338) are secured on the top closing tool carrier and closing tool bottom parts (450, 456) are fixed on the bottom tool carrier (4) and are periodically moved towards one another by the rotation of the tool carriers (4, 5) and in a coupling phase cooperate to fix the lid foil.

9. Apparatus according to claim 4, 6 or 8, characterised in that the closing tool bottom parts (450, 456) are disposed on the cross-members (210, 220) concentrically of the carrier plate (431).

10. Apparatus according to claim 8 or 9, characterised in that the closing tool bottom parts comprise a pressure frame (456) and a centring cage (450).

11. Apparatus according to claim 10, characterised in that the pressure frame (456) and the centring cage (450) are of integral construction).

12. Apparatus according to claim 10, characterised in that the centring cage (450) is mounted for vertical displacement with respect to the pressure frame (456).

13. Apparatus according to claim 12, characterised in that the vertical movement of the centring cage (450) with respect to the pressure frame (456) is controlled via a cam roller (454) running in a guide groove (455).

14. Apparatus according to claim 13, characterised in that the guide groove (455) is mounted in a stationary cam strip (435), the horizontal bottom edge of said strip forming the guide rail (434) for the cross-member plate (433).

15. Apparatus according to claim 4, characterised in that the cam strip (435) extends symmetrically on either side of the vertical central plane (ME) in each case by approximately half the radius of the rotary blades (410, 420).

16. Apparatus according to claim 14 or 15, characterised in that the cam strip is constructed as part of an upright hollow shaft (201) mounted on the central shaft (2) between the rotary blades (410, 420).

17. Apparatus according to claim 16, characterised in that the hollow shaft (201) is connected to an inner sunwheel (440) which is held stationary via inner planetary gears (441) which are driven on common planetary shafts (439) by outer planetary gears (438) rotating about the outer sunwheel (436) belonging to the synchronus planetary gear.

18. Apparatus according to at least one of claims 4 to 17, characterised in that a locking device (460, 461) is provided to prevent abrupt acceleration of the rotary blades (410, 420; 510, 520) by relievig forces after said blades have traversed the vertical central plane (ME).

19. Apparatus according to claim 18, characterised in that the locking device (460, 461) comprises opposite engagement rollers (461) at the periphery of the rotary blades (410, 420) of the bottom tool carrier (4) and a locking disc (460) of smaller diameter than the rotary blades, the axis of which is situated in the vertical central plane (ME), which has two 180_° offset recesses to receive the engagement rollers (461) and which is driven at the same circumferential speed as the rotary blades (410, 420) but in the opposite direction thereto by a transmission gear.

20. Apparatus according to claim 19, characterised in that recesses are formed in the periphery of the rotary blades (510, 520) of the upper tool carrier (3), in which recesses engage the engagement rollers (461) of the rotary blades of the bottom tool carrier (4).

21. Apparatus according to at least one of claims 3 to 20, characterised in that an intermediate transport device (650) takes over the containers from the conveyor belt (601) by means of conveyor dogs (651) guided for rotation on a chain (655) and extending transversely of the direction of conveyance and pushes them, via transition skids (603) extending in the transport plane, on to the container carriers (431) guides horizontally in the transport plane (HE).

22. Apparatus according to claim 21, characterised in that the conveyor (651) are swung rear- wardlyaway from the containers in the transport plane by a roller cam control system (656, 657) after the containers have been transferred to the container carrier.

23. Apparatus according to claim 22, characterised in that the conveyor dogs (651) are swung back into the conveyor path by a raoller cam control system (656, 658) behind the closed containers after the latter have been closed and push the containers off the container carrier (431) via intermediate skids (604) on to a discharge conveyor belt (670).

24. Apparatus according to claim 8, charcterised in that the closing tool top and bottom parts (334, 337, 338; 450, 456) are constructed as tools by means of which the lid foil is fixed on the containers to form a flanged closure.

25. Apparatus according to calim 24, characterised in that the closing tool top part comprises slides (334) known per se which in a closing position fold the lid foil beneath the edge flange of the container.

26. Apparatus according to claim 25, characterised in that the slide movement is controlled by utilization of the relative movement between the cross-members (310, 320) and the rotary blades (510, 520) of the closing tool carrier (5).

27. Apparatus according to claim 26, characterised in that control cams (342, 343) are provided on at least one of the two rotary blades (510, 520) to control the slide movement and act, via rollers (344), rocker arms (345) and coupling rods, on a pivoting disc (331) disposed on the cross-member, which transmit the pivoting movement thereof to the slides (334) via links (333).

28. Apparatus according to claim 8, charcater- ised in that the closing tool top and bottom parts are constructed as tools be means of which lid foil is secured on the containers to form a seal closure.

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