EP2634100A1 - Tray sealer and method for transporting trays - Google Patents

Abstract

The tray sealing machine (1) comprises a sealing station (2) for sealing trays (3) with a cover film (4), and a conveyor system (14) for conveying the trays along a conveying path (13). The conveying system comprises multiple pushers (21), which are configured for carrying the tray and is moved along an endless pusher path (15). The pushers are movable independently of one another along the pusher path. Each pusher is movable along the pusher path with an individual speed profile. The pusher path has a conveying section (16) assigned to the conveying path and a return section (17). The pushers are movable on the return section at a higher speed than on the conveying section. An independent claim is included for a method for conveying trays by a conveyor system up to, into or from a tray sealing machine sealing the trays with a cover film.

Description

The invention relates to a tray sealing machine with a sealing station according to the preamble of claim 1, and to a method for transporting trays by means of a transport system to, in and / or from a tray sealing machine which seals the trays with a cover film.

In the tray sealing machines known from practice, trays are generally transported by means of a transport system up to a sealing station. In this sealing station, the shells previously filled with a product are sealed by means of a cover film and thus sealed. Optionally, the trays may be previously evacuated and / or gassed with a replacement gas or gas mixture. For transferring the shells from a feed belt in the sealing station, a gripper system is often used, as for example from the DE 10 2010 027 211.6 evident.

In another, generic type of shell sealing machines, the shells are on a transport route and are detected there by carriers and transported forward. These drivers are often transverse rods extending across the transport path and each being clamped at their two ends in a transport chain. As a result, they necessarily have a constant distance from each other, which is greater than the length of a shell in the transport direction.

Circulating transfer systems for transporting products, but not for use in a tray sealing machine, are known from WO 00/48908 A1 , of the DE 10 2009 003 080 A1 or the DE 10 2010 028 333 A1 known.

The object of the present invention is to improve a tray sealing machine and a method for transporting trays in terms of their efficiency.

This object is achieved by a tray sealing machine with the features of claim 1 and by a method having the features of claim 11. Advantageous developments of the invention are specified in the subclaims.

The tray sealing machine according to the invention is characterized in that the carriers configured to take along at least one tray are movable independently of one another along the carrier path. In other words Thus, any two drivers no longer necessarily have a constant distance from each other and the same speed. Rather, the distances and speeds between any, especially adjacent drivers may differ. Surprisingly, this significantly increases the efficiency of the tray sealing machine. Because this way, it is possible, for example, even without the use of elaborately synchronized conveyor belts to vary the distances of the shells along their transport path to adjust these distances, for example, along the transport route changing requirements. For example, the trays could be given a slower speed along a fill line to be better filled while being quickly transported to a sealing station. The variable distances between adjacent drivers make it possible to adjust the distances between the shells particularly well to the dimensions of a sealing tool.

In a comparatively simple variant, the speed profiles of the different drivers along the driving path are the same, even if different drivers are at different points in their speed profiles at any given time. However, in a more elegant embodiment, each driver with an individual velocity profile is movable along the driver track to further enhance the flexibility of the tray sealer application. For example, the tray closure machine's transport system can respond to irregularly arriving trays and even create a regular array of trays from irregularly arrived trays.

Usually, the driving track will have a transport section for the shells associated transport section and a return section. It is favorable if the drivers are movable on the return section at a higher speed, at least at a higher average speed, than on the transport section. This makes it possible to quickly return the released after the transport of a shell driver back to the starting point of the transport section, so that a total of a smaller number of carriers is needed.

Preferably, at least one linear motor for driving the drivers is provided along the driving path. Such a linear motor is known in practice. He has a sequence of electromagnets along the endless, ie closed Mitnehmerbahn are arranged. The driver itself or a carriage to which the driver is attached, serve as a rotor of the linear motor and are movable along the path of the linear motor by changing magnetic fields. In order to create a distance between the windings of the electromagnets and the rotor, wheels, airbags or an electromagnetically generated floating effect could be used.

It is conceivable that at least one position sensor for detecting the position of a shell and / or the position of a driver is provided. Such a position sensor further enhances the efficiency of the tray sealing machine. By means of the signal of the position sensor can be ensured that a shell is reliably detected by a driver, and that even with irregularly arriving trays in each case a driver is available at a suitable time.

In a development of the invention, a buffer section for buffering a plurality of shells can be provided along the transport path. Such a buffer section is characterized in that the shells have a lower speed there on average and / or have smaller distances from one another. The buffer section allows subsequent stations, such as the sealing station of the tray sealing machine, to be supplied as evenly as possible with a stream of trays so as to ensure uniform operation of the tray closing machine.

It is also possible that the transport system has not one but two, three or generally several tracks for transporting a plurality of juxtaposed tracks of trays. Compared to a single-lane design of the tray sealer, this increases throughput, i. the number of shells transportable per unit of time along a particular section of track.

If the transport system has multiple tracks, it is possible that the carriers of different tracks are independently movable. This makes it possible to detect also irregularly arriving on adjacent tracks trays and to transport on.

In a further variant, it is possible that adjacent carriers of different tracks can be coupled in sections along the transport route in their speed. In particular, this coupling of speeds could occur If the carriers have taken exactly the same position along the transport route, so that the trays covered by them lie exactly next to each other. In this way, the shells can be processed particularly well, for example by a sealing tool.

Preferably, moreover, at least some or even all the drivers are each movably mounted on a carriage movable along the carrier path relative to this carriage. This makes it possible to remove the drivers from the area around a shell closing sealing tools, so that the sealing tools can form a hermetically sealed sealing chamber, without interfering with the driver.

For example, the driver could be provided pivotably and / or translationally movable on the carriage. For example, it could simply be moved horizontally and transversely to the transport direction of the shells to the outside. It would also be possible that the driver for this purpose has a variable length and is constructed, for example, telescopic.

The invention also relates to a method for transporting trays by means of a transport system. According to the invention, the carriers are moved independently along a Mitnehmerbahn the transport system in this method to allow the above-mentioned advantages.

It has already been explained that the carriers are preferably moved faster along a return section of the transport system than along a transport section of the transport system, and that the trays can optionally be transported along the transport route not only in one lane but in several adjacent lanes. Usually, these tracks will be arranged parallel to each other. It is possible in particular that adjacent carriers of different tracks are moved in sections along the transport route at the same speed.

In a variant of the method, at least some carriers are respectively mounted on a carriage which is movable along the carrier path, namely movable relative to this carriage, so that they can be moved out of the area of this sealing tool before closing a sealing tool.

Figur 1

ein Ausführungsbeispiel einer erfindungsgemäßen Schalenverschließmaschine in schematischer Darstellung,

Figuren 2 - 5, 6a, 6b und 6c

in schematischer Darstellung unterschiedliche Varianten des Transportsystems für die erfindungsgemäße Schalenverschließmaschine und

Figur 7

in Draufsicht eine weitere Variante des Transportsystems für die erfindungsgemäße Schalenverschließmaschine.

In the following, advantageous embodiments of the invention will be explained in more detail with reference to a drawing. In detail show:

FIG. 1

An embodiment of a Schalenverschließmaschine invention in a schematic representation,

Figures 2-5, 6a, 6b and 6c

in a schematic representation of different variants of the transport system for the peel sealer according to the invention and

FIG. 7

in plan view, a further variant of the transport system for the invention Schalenverschließmaschine.

The same components are provided throughout the figures with the same reference numerals.

FIG. 1 shows a schematic representation of a Schalenverschließmaschine invention 1 with a sealing station 2, in the shells 3, in particular plastic trays, can be closed with a cover sheet 4. The cover film 4 is unrolled from a film roll 5 and guided over a deflection roller 6 in the sealing station 2. On the other side of the sealing station 2, a further deflecting roller 7 deflects the remaining film grid of the cover film 4 onto a residual film winder 8.

The sealing station 2 has in the usual way a lower tool 9 and an upper tool 10. These tools 9, 10 of the sealing station 2 are in FIG. 1 shown in an open position. However, they may be transferred to a closed position in which they form between them a hermetically sealed sealing chamber 11 in which the trays 3 filled with a product 12 can be evacuated and / or fumigated before being sealed.

The tray sealing machine 1 has a transport path 13 along which the trays 3 are transported in a transport direction T to the sealing station 2, through the sealing station 2 and from the sealing station 2. The transport path 13 may be formed, for example in the form of a support or sliding plane on which rest the shells 3. In particular, it would be conceivable that the trained as a support transport section 13 has a slot or an interruption, so that a below the Transport path 13 arranged transport system 14, the shells 3 detect and can transport along the transport path 13.

Alternatively, it would be possible for the transport system 14 to laterally surround the transport path 13.

The transport system 14 has an endless carrier track 15. This carrier track 15 in turn has a first, straight, the transport path 13 associated and located directly below this transport section 13 transport section 16, and also a rectilinear, located below or next to the transport section 16 return section 17 and two the two aforementioned sections 16, 17 connecting , Curved connecting portions 18, 19. On the driving track 15 is a finite number of carriages 20 which are movable along the driving path 15. Each carriage 20 has a driver 21, which is designed with respect to its size and stability to take away at least one shell 3 and protrudes in the present embodiment for this purpose from below through a slot in the transport path 13 so that the upward on the transport path 13 also protruding portion of the driver 21 can detect and take a shell 3. For example, the driver 21 may be designed for this purpose as a rod, as a plate or as a bracket.

To move the carriage 20 and thus the driver 21, the driving track 15 is formed as a whole linear motor 22. Thus, the Mitnehmerbahn 15 forms the stationary part of the linear motor 22, whose movable part or runners are formed by the carriage 20. The Mitnehmerbahn 15 is divided into fine sections 23, which are shown for clarity only in a short range. By means of a suitably programmed or programmable controller 24, a variable magnetic field can be applied to the individual sections 23 in such a way that this magnetic field moves the carriages 20 along the carrier track 15. In this case, located on the transport section 16 carriage 20 and driver 21 move in the transport direction T of the shells, while they move on the return section 17 in the reverse direction.

The sections 23 of the linear motor 22 are configured so that they can be controlled individually by the controller 24. This makes it possible according to the invention, the individual Driver 21 independently, in particular independently of the respective adjacent carriages and carriers 21 to move along the driving path 15. Thus, it is even possible that each driver 21 along the carrier track 15 receives its own, individual speed profile.

Position sensors 25, 26, for example in the form of light barriers or cameras, are used to detect a position of a shell 3 or a driver 21. A first position sensor 25 is arranged at the beginning of the transport path 13 to there the position and the presence of a shell 3 to capture. The position sensor 25 may be located above, below or next to the transport path 13. A second position sensor 26 is arranged at the end of the return section 17 of the carrier track 15 in order to detect there the presence and the position of a carriage 20 with a driver 21 and / or the condition and in particular possible defects of the driver 21. Independently of these position sensors 25, 26, the transport system 14 may have its own position detection system for real-time detection of the position of each individual carriage 20.

An embodiment of the method according to the invention or the operation of the tray sealing machine 1 will be explained below.

In an insertion region 28 of the transport path 13, trays 3 are made available to the transport system 14, for example manually or by a destacker. The arrangement of the shells 3 may be irregular in the insertion region 28. The position of each individual shell 3 is detected by the position sensor 25 and transmitted to the controller 24. This ensures by appropriate control of the linear motor 22 of the carrier track 15 that each tray 3, a carriage 20 is provided with a driver 21. This driver 21 detects the respective shell 3 and ensures their transport along the transport path 13.

The empty shells 3 reach along the transport path 13 to a filling line 29. Along the filling section 29, the shells 3 are filled with a product 12. This filling can be done automatically or manually. The individual control of the driver 21 allows that the driver 21 and the shells 3 covered by them the Reach equidistant filling line 29, even if they were originally used in an irregular arrangement.

The control of the driver 21 is further carried out so that the shells 3 occupy a minimum distance from each other along the filling section 29. This reduces the likelihood that a product passes between the trays 3 on the transport path 13. In addition, the small distances between the shells 3 facilitate the filling of the shells. The filling section 29 may be designed for this purpose as a buffer section of the transport path 13, which is designed to buffer a variable number of shells 3. However, the buffer section may also be formed separately from the filling section 29. Along the filling path 29, the speed of the carriage 20 and thus the driver 21 and the shells 3 is reduced.

In a subsequent section 30 of the transport path 13, the shells 3 are again accelerated to a higher speed and brought to mutual distances A from each other, which correspond to the distances of the shells 3 in a sealing tool 31 of the sealing station 2. The speed of the drivers 21 and the shells 3 along the portion 30 can be controlled precisely so that a suitable group of shells 3 enters the sealing station 2 immediately after the opening of the lower and upper tool 9, 10 of the sealing station 2.

In the sealing station 2, the carriages 20 and thus the trays 3 are stopped. If necessary, carriages 20 are moved back out of the sealing station 2 or the drivers 21 are removed from the region of the sealing station 2. Lower and upper tool 9, 10 of the sealing station 2 close. The sealing chamber 11 is evacuated and, if appropriate, fumigated before the sealing tool 31 seals the cover film 4 to the shells 3. After opening the sealing station 2, the closed trays 3 are transported out of the sealing station 2 and removed. The carriage 20 and catch 21 freed from the shells 3 are accelerated and moved along the return section 17 at a higher speed than on the transport section 16 until the end of the return section 17. There, the free and available carriers 21 accumulate in a storage area 32. The position of the foremost carrier 21 is monitored by means of the position sensor 26. As soon as the position sensor 25 gives a corresponding signal, the foremost driver 21 is accelerated via the connection section 19 in order to detect a new shell 3.

FIG. 2 shows the embodiment according to FIG. 1 once again in a more abstract form. On the insertion area 28, the empty trays 3 are placed on the transport path 13 and detected there by free carriers 21. On the buffer section 29, the distances between adjacent shells 3 are minimized in order to be able to buffer as many shells 3 there as possible over the shortest possible distance. On the subsequent grouping section 30, the trays 3 are accelerated and their distances are adapted to the dimensions of the sealing tool 31.

FIG. 3 In a likewise abstracted form, a variant of the transport system 14 is shown. It differs from the first exemplary embodiment in that the trays 3 in the insertion region 28 are taken over by an upstream conveyor belt 33 onto the transport path 13. The position sensor 25 detects the position of the possibly irregularly arriving shells. 3

FIG. 4 shows an equally abstract representation of another variant of the transport system 14, but this time in plan view. In the insertion region 28, the shells 3 are placed on the transport path 13 and detected by the drivers 21. In the buffer area 29, the shells 3 are buffered and can be optionally filled there. In the grouping section 30, the distances between the shells 3 increase. In the present exemplary embodiment, groups of three shells each are formed there, which are fed together as a group to the sealing station 2. The sealing station 2 is configured to collectively seal a group of three trays 3 in this example. Beyond the sealing station 2, the transport path 13 comprises a separating section 34. By suitable, individual control of the driver 21, the distances between adjacent shells 3 are increased on the separating section 34 in order to separate the shells from each other. This facilitates individual removal of the filled and sealed trays 3 and also individual process steps such as weighing, checking and / or labeling of the finished trays 3.

FIG. 5 also shows in plan view and also in abstract form another embodiment of the transport system 14. In this case, the transport system along the transport path 13 has three adjacent tracks S1, S2, S3. Trays 3 can be transported on each of the parallel tracks S1, S2, S3. For this purpose, under each of the three tracks S1 to S3 each have their own carrier track 15 with its own drivers 21 as in FIG. 1 intended.

Along the insertion area 28, the trays 3 do not necessarily have to be inserted in a regular shape. The individual control of the driver 21 still makes it possible to move the trays 3 on the individual tracks S1 to S3 so that from a position 35 trays 3 on all three tracks S1 to S3 are directly adjacent to each other and at the same height.

The FIGS. 6a to 6c show different operating variants that result with a multi-lane transport system 14. FIG. 6 corresponds to the already on the basis of FIG. 5 described situation in which an irregular arrangement of shells 3 along the three tracks S1 to S3 in a regular arrangement with immediately adjacent and at the same height shells 3 is transferred. In each case, there is a shell 3 on each of the three tracks S1, S2, S3.

In FIG. 6b is a larger shell 3 ', which extends in the transverse direction over all three tracks S1 to S3, transported along the transport path 13. With such wide shells 3 ', it is sufficient if only two of the drivers 21 on the three tracks S1 to S3 on the shell 3' attack.

FIG. 6c shows another variant. In this, along the first track S1, a shell 3 having the same dimension as originally transported. However, a further shell 3 "is wider and is transported on the two other tracks S2, S3. With suitable stabilization of the shell 3", it is sufficient if only one of the two drivers 21 of the two tracks S2, S3 acts on the more ready shell 3 " ,

FIG. 7 schematically shows a plan view of a further variation possibility, which lends itself to all embodiments of the invention Schalenverschließmaschine 1, in which due to the dimensions of the sealing station 2 in the transport direction T consecutively several shells 3 seal at the same time. In this embodiment, the transport path 13 has two tracks S1, S2. The sealing station 2 or its sealing tool 31 are large enough to simultaneously detect and seal a group of four shells, ie in each case two shells 3 on each of the two parallel tracks S1, S2.

The Mitnehmerbahnen 15 for the carriage 20, on which the drivers 21 are mounted, are in this embodiment, in each case adjacent to the two tracks S1, S2. The drivers 21 protrude in a transport position on the transport path 13 so that they each detect a shell 3.

As soon as a group of four shells 3 has arrived in the sealing station 2 in this embodiment, they are stopped there. This is done by the propulsion of these carriages 20 is terminated by the individual control of the carriage 20 along the Mitnehmerbahnen 15. The carriages 20 and drivers 21 of the rear two shells 3 in the transport direction T can now leave their dashed position and be moved back a short distance Z until their drivers 21 are outside the region of the sealing station 2 and therefore a closing movement of the tools 9, 10 of the sealing station 2 no longer hinder.

For the carriage 20 and driver 21 of the front two shells 3, however, this is obviously impossible, because they would move the rear two shells 3 again in a backward movement Z. In the present embodiment, however, the drivers 21 are movably mounted on their associated carriage 20. Concretely, the dogs 21 are configured to move linearly, horizontally, outward through the carriages 20 until they are completely outside the area of the sealing station 2. Alternatively, it would be conceivable that the drivers 21 are formed telescopically and can shorten their length and / or that they are pivotally mounted on the carriage 20 and can thus be removed from the area of the sealing station 2. In this way, no one of the drivers 21 obstructs the sealing tools 9, 10, if they close to form the sealing chamber 11.

These possibilities for moving out of carriers from a sealing station 2 can also be generally provided and advantageous in tray sealing machines, independently of the forms of the transport system 14 according to the invention explained in this document.

Starting from the illustrated embodiments, the tray sealing machine 1 according to the invention and the method according to the invention can be modified in many ways. For example, it is conceivable to mount the drivers 21 movably on the associated carriages 20 even with single-track tray closing machines and transport systems 14.

It would also be conceivable for the sealing station 2 to have, per track S1, S2, S3, a group of lower tool 9, upper tool 10 and sealing tool 31 which can be operated independently of the other tracks. For each of these groups, a separate film roll 5 and a Restfolienaufwickler 8 may be provided.

Claims (15)

A tray sealing machine (1) with a sealing station (2) for closing trays (3) with a cover film (4), furthermore with a transport system (14) for transporting the trays (3) along a transport path (13), wherein the transport system (14 ) has a plurality of drivers (21) which are each designed to carry at least one shell (3) and are movable along an endless carrier path (15),
characterized in that the drivers (21) are independently movable along the carrier track (15). Cup closing machine according to claim 1, characterized in that each driver (21) with an individual speed profile along the driving path (15) is movable. Cup closing machine according to one of the preceding claims, characterized in that the driving track (15) has a transport section (13) associated transport section (16) and a return section (17), and in that the driver (21) on the return section (17) with higher Speed than on the transport section (16) are movable. Cup closing machine according to one of the preceding claims, characterized in that at least one linear motor (22) for driving the drivers (21) is provided along the carrier track (15). Cup closing machine according to one of the preceding claims, characterized in that at least one position sensor (25, 26) for detecting the position of a shell (3) and / or the position of a driver (21) is provided. Cup closing machine according to one of the preceding claims, characterized in that a buffer section (29) for buffering a plurality of trays (3) is provided along the transport path (13). Cup closing machine according to one of the preceding claims, characterized in that the transport system (14) has a plurality of tracks (S1, S2, S3) for transporting a plurality of adjacent tracks of trays (3). Cup closing machine according to claim 7, characterized in that the drivers (21) of different tracks (S1, S2, S3) of the transport system (14) are movable independently of each other. Cup closing machine according to one of claims 7 or 8, characterized in that adjacent carriers (21) of different tracks can be coupled in sections along the transport path (13) in their speed. Cup closing machine according to one of the preceding claims, characterized in that at least some carriers (21) are each movably mounted on a carriage (20) movable along the carrier path (15) relative to said carriage (20). Method for transporting trays (3) by means of a transport system (14) to, in and / or from a tray closing machine (1) which seals the trays (3) with a cover film (4),
wherein carriers (21) of the transport system (14) are movable along an endless carrier track (15), the trays (3) are captured by the drivers (21) and transported along a transport path (13),
characterized in that the drivers (21) are moved independently of each other along the driving path (15). A method according to claim 11, characterized in that the drivers (21) along a return section (17) of the transport system (14) are moved faster than along a transport section (16) of the transport system (14). Method according to one of claims 11 or 12, characterized in that the shells (3) along the transport path (13) in a plurality of adjacent tracks (S1, S2, S3) are transported. A method according to claim 13, characterized in that adjacent carriers (21) of different tracks are moved in sections along the transport path (13) at the same speed. Method according to one of claims 11 to 14, characterized in that at least some entrainment means (21) are each movably mounted on a carriage (20) movable along the driving path (15) relative to said carriage (20) and before closing a sealing tool ( 9, 10) are moved out of the area of this sealing tool (9, 10).

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