Abstract:
The invention concerns a four-lane tray sealer, which has two double lanes for sealing trays with a cover film, wherein the double lanes can be operated independently from one another.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This Application claims priority to German Application Number 102011119858.3 filed Nov. 30, 2011, to Alireza Taghipour, Bernd Jokele and Lars Ickert entitled “Multi-Lane Tray Sealer,” currently pending, the entire disclosure of which is incorporated herein by reference. 
       FIELD OF THE INVENTION 
       [0002]    The invention relates to a multi-lane tray sealer for sealing trays with a cover film in two double lanes. 
       BACKGROUND OF THE INVENTION 
       [0003]    From DE 10 2008 030 510 A1 of the applicant, a tray sealer is known in which the trays to be sealed are taken from an infeed belt by a pair of grippers and transported to a sealing die. During this process, the pair of grippers grips the trays by two gripper arms approaching one another from the sides of the trays until the trays are securely grasped and can be conveyed independently of the motion of the infeed belt. 
         [0004]    Furthermore, in unpublished DE 10 2011 108 919, also from the applicant&#39;s firm, a two-lane tray sealer is described that likewise has a pair of grippers to transport trays from an infeed belt to a sealing die. In this design, a vertical arrangement is provided between the two lanes. The pair of grippers grips the trays on the infeed belt by means of one gripper arm provided on each side of the trays by pressing each of the trays against the vertical arrangement, and the gripper arms push the gripped trays along the arrangement into the sealing station. 
         [0005]    So as to provide high capacity (trays to be processed per minute), two-lane tray sealers with sealing dies that are large in the direction of production are frequently employed. The size of these dies is limited, however, since the weight of the dies no longer permits ergonomic handling or the capacity of the lifting device is no longer sufficient in terms of closing force and speed of motion. 
         [0006]    From DE 199 12 491 A1 of the applicant, a multi-lane tray sealer is known, for example with four lanes. The transport of trays is accomplished neither by means of grippers nor by means of conveyor belts. Tray carriers that are guided from the side by means of a chain are provided for the transport of trays, wherein a drive of the chain provides for the feed of the tray carriers. The tray carrier can be provided with one row and for four lanes, for example, with four trays located adjacent to one another being transported as a group. Such tray sealers require a small amount of installation space in a production facility, especially with regard to width, and have high capacity on account of their multi-lane design. Capacity is defined as the number of packages that can be produced per unit time. Because of the large number of tray carriers, which must match the shape of the trays in order to accommodate the trays, when a batch change occurs during production to a tray with a different dimension, a very time-consuming and labor-intensive changeover is the adverse consequence. Complicated and expensive production facilities and conveyor systems are placed before and after such high-capacity, multi-lane tray sealers, and the desire is to retain them unchanged when the tray sealer is replaced. When replacing the tray sealer, it is important to take the existing installation circumstances into account, since the existing installation area does not permit a greatly increased space requirement for a new tray sealer. 
       SUMMARY OF THE INVENTION 
       [0007]    The object of the present invention is to be able to replace a tray sealer, preferably a four-lane tray sealer, having tray carriers for tray transport, with a tray sealer having gripper arms and the identical number of lanes and equal capacity, with the intended result of increasing flexibility and reducing down time for changeover to different tray dimensions. 
         [0008]    The tray sealer according to the invention for sealing trays with a cover film in two double lanes comprises a controller, a first and a second gripper, and a first and a second workstation, wherein the first workstation and the first gripper work together with a first double lane, and the second workstation and the second gripper work together with a second double lane, in such a manner that trays on the first double lane can be processed independently from trays on the second double lane. Such a tray sealer with four lanes not only has a capacity that is approximately twice as great as that of a single two-lane tray sealer, but also has a space requirement that is considerably smaller than that of two two-lane tray sealers. A reduction in the space requirement of such a high-capacity, four-lane tray sealer makes it possible to exchange or replace an existing tray sealer that has tray carriers in an existing production facility. 
         [0009]    The user is provided with the advantage of processing trays on one double lane while the other double lane, including the dies of the workstation, is being cleaned, maintained, or changed over. This may be the case during a film replacement of the cover film, for example, in order to replace an empty roll with a new, full roll. 
         [0010]    The controller may be designed to separately control the grippers, workstation, and conveyor belts of each double lane. This makes it possible to process trays on one double lane while the other double lane is stopped. In this way, it is also possible to dimension a device such as a vacuum pump to be smaller and thus more energy-efficient, since the controller can control the processing of the two double lanes in a manner staggered in time such that the vacuum pump is not needed for evacuation at both workstations at the same time. 
         [0011]    In one embodiment, at least two operating terminals are provided for independently processing trays on the first and second double lanes. This makes parallel operation possible for the two double lanes, and also operation of both double lanes from one of the two operating sides of the tray sealer. 
         [0012]    Another advantage of the invention is achieved when a film dispenser and a film trim rewinder are provided for each of the two double lanes, for example in order to seal trays with different cover films. The cover films here can have different designs, for example for different customers. 
         [0013]    A partition can be provided between the first and second double lanes in order to ensure that work, for example a film change or die change, can be carried out on a first double lane by the operating personnel without danger even though the second double lane remains in operation. 
         [0014]    In this design, it is advantageous for the partition to extend in the direction of production from the start of a transport region of the gripper arms along the workstation to the end of the transport region of the gripper arms in order to prevent operator access to power-driven elements of the double lane on the other side of the partition, and thus preclude injuries. 
         [0015]    In one embodiment, an upper die part and a lower die part of the first workstation and an upper die part and a lower die part of the second workstation can be removed from the tray sealer in opposite directions from one another with respect to the double lanes and perpendicular to the direction of production. In this way, it is possible to change dies, and analogously gripper arms, without the need to provide space between the double lanes for the operating personnel and in order to be able to keep the space requirement of the tray sealer to a minimum despite maximum performance. 
         [0016]    The tray sealer may include distribution boxes for electrical and/or pneumatic components located below infeed devices or outfeed devices, wherein the distribution boxes have accessibility perpendicular to the direction of production for an operator or service technician for maintenance purposes. This makes it possible to minimize the spacing between the first and second workstations for each double lane, since accessibility between the workstations is no longer necessary. 
         [0017]    A spacing between the first double lane and the second double lane can be smaller than a width of the first or second double lane, in order to keep the space requirement of the tray sealer to a minimum. 
         [0018]    Other and further objects of the invention, together with the features of novelty appurtenant thereto, will appear in the course of the following description. 
     
    
     
       DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         [0019]    In the accompanying drawing, which forms a part of the specification and is to be read in conjunction therewith in which like reference numerals are used to indicate like or similar parts in the various views: 
           [0020]      FIG. 1  is a schematic view of a tray sealer in accordance with one embodiment of the present invention; and 
           [0021]      FIG. 2  is a schematic top view of the tray sealer in accordance with one embodiment of the present invention. 
       
    
    
       [0022]    Identical components in the figures are labeled with identical reference symbols through-out. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0023]    The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. For purposes of clarity in illustrating the characteristics of the present invention, proportional relationships of the elements have not necessarily been maintained in the drawing figures. 
         [0024]    The following detailed description of the invention references specific embodiments in which the invention can be practiced. The embodiments are intended to describe aspects of the invention in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments can be utilized and changes can be made without departing from the scope of the present invention. The present invention is defined by the appended claims and the description is, therefore, not to be taken in a limiting sense and shall not limit the scope of equivalents to which such claims are entitled. 
         [0025]      FIG. 1  shows a perspective view of a tray sealer  1  according to the invention. Located on a frame  2  are a first workstation  3   a  and a second workstation  3   b,  in the present case a gas flushing, sealing and cutting station. The workstations may each have a lower die part  20  and an upper die part  21 . A first infeed conveyor  4   a  and a second infeed conveyor  4   b,  implemented as conveyor belts, and a subsequent first collecting conveyor  5   a  and second collecting conveyor  5   b  (hidden in this view), implemented as conveyor belts, transport filled trays  6  to the workstations  3   a,    3   b.  A first gripper  7   a  and a second gripper  7   b,  each with two gripper arms  8 , grip the trays  6  and convey them into the workstations  3   a,    3   b.  A first cover film  10   a  and a second cover film  10   b  can be drawn from a first film dispenser  9   a  and a second film dispenser  9   b  and are likewise guided into the workstations  3   a,    3   b.  After evacuation and/or gas flushing of the trays  6  with an exchange gas (MAP), the trays  6  can be sealed airtight with the cover film  10   a,    10   b  drawn from the film dispensers  9   a,    9   b.  Afterwards, simultaneously, or beforehand, a cutting tool cuts the cover film  10   a,    10   b.  The residual film trim from the film  10   a,    10   b  may be wound onto a first film trim rewinder  11   a  and a second film trim rewinder  11   b.  The sealed and singulated packages  12  are placed on a first outfeed belt  13   a  or on a second outfeed belt  13   b,  implemented as conveyor belts, and are thus transported out of the workstations  3   a,    3   b  and out of the tray sealer  1  in the direction of production P. Two operating terminals  14   a,    14   b  may be provided to visually display the operation and the operational state of the tray sealer  1  and make it possible for one operator to operate the tray sealer  1 . Control cabinets  30 , for example for a service technician, can be located below the infeed belts  4   a,    4   b  and the outfeed belts  13   a,    13   b,  which control cabinets can be opened, and are thus accessible, perpendicular to the direction of production P and facing away from the machine. 
         [0026]      FIG. 2  shows that the tray sealer  1 , which can process four lanes S of trays  6 , can be divided in the direction of production P into a right part la and a left part  1   b,  which process a first double lane DS 1  and a second double lane DS 2 . A spacing B perpendicular to the direction of production P between the first double lane DS 1  and the second double lane DS 2  in the region of the collecting conveyors  5   a,    5   b  or in the region of the workstations  3   a,    3   b  may be smaller than a width A of the first double lane DS 1  or the second double lane DS 2 . The spacing A is defined by the width of two trays placed one beside the other on a double lane DS 1 , DS 2  of an infeed belt  4   a,    4   b  or outfeed belt  13   a,    13   b.  The right part la of the tray sealer  1  can be operated via the operating terminal  14   a  and the left part  1   b  of the tray sealer  1  can be operated via the operating terminal  14   b.  It is also possible for only one common operating terminal to be provided for both parts  1   a  and  1   b.  In this design, this terminal can be attached to a pivoting arm  15  so that the tray sealer  1  can be operated from both sides. A common controller  16  can be provided in the control cabinet, which can be located in or on the tray sealer  1 . It is likewise possible for two separate controllers to be provided for the two parts  1   a  and  1   b.  The controller  16  may be connected to the operating terminals  14   a,    14   b  for data exchange. 
         [0027]    The two parts  1   a  and  1   b  of the tray sealer  1  can each have a workstation  3   a,    3   b,  a collecting conveyor  5   a,    5   b,  an outfeed conveyor  13   a,    13   b,  a gripper  7   a,    7   b  with two gripper arms  8 , a film dispenser  9   a,    9   b,  a cover film  10   a,    10   b,  and a film trim rewinder  11   a,    11   b.  A partition  17  between the two parts  1   a  and  1   b  provides safety separation of the two parts  1   a,    1   b  of the tray sealer  1 . The partition  17  ensures that no operator of the part  1   a  can reach into the operating region of the part  1   b,  and vice versa, with parts of his body. While the part  1   a  seals trays  6  with a cover film  10 , the part  1   b  can be cleaned or maintained. A die change at the workstations  3   a,    3   b  is also possible. Depending on the quantity of trays  6  supplied, the two parts  1   a  and  1   b  can be operated with different capacities. 
         [0028]    For reasons of clarity, covers on the sides and top of the workstations  3   a,    3   b  and in the region of the collecting conveyor  5   a,    5   b  and the outfeed belts  13   a,    13   b  are not shown in the drawings. 
         [0029]    From the foregoing, it will be seen that this invention is one well adapted to attain all the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure. It will be understood that certain features and sub combinations are of utility and may be employed without reference to other features and sub combinations. This is contemplated by and is within the scope of the claims. Since many possible embodiments of the invention may be made without departing from the scope thereof, it is also to be understood that all matters herein set forth or shown in the accompanying drawings are to be interpreted as illustrative and not limiting. 
         [0030]    The constructions and methods described above and illustrated in the drawings are presented by way of example only and are not intended to limit the concepts and principles of the present invention. Thus, there has been shown and described several embodiments of a novel invention. As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. The terms “having” and “including” and similar terms as used in the foregoing specification are used in the sense of “optional” or “may include” and not as “required”. Many changes, modifications, variations and other uses and applications of the present construction will, however, become apparent to those skilled in the art after considering the specification and the accompanying drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow.