Abstract:
A race track conveyor having at least two conveyor belts. Each conveyor belt includes a separate drive allowing each conveyor belt to independently transport a group of products from a first end to a second end of the race track conveyor. Each conveyor belt may include two belts, each belt being driven by the respective drive of the conveyor belt. The present race track conveyor may include three conveyor belts. The present race track conveyor may be configured to process different formats when loading and unloading product onto the race track conveyor allowing the race track conveyor to move product machines that have different work cycles.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This Application claims priority to European Patent Application Number 13170642.6 filed Jun. 5, 2013, to Peter Bergler entitled “Race Track Conveyor and Packaging Facility,” currently pending, the entire disclosure of which is incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The invention relates to a race track conveyor and a packaging facility including the race track conveyor. 
     BACKGROUND OF THE INVENTION 
     Race track conveyors are known to comprise up to three race tracks that are each drivable separately from each other so that each race track can transport a group of products. Such triple belt conveyors comprise three axles with drive wheels and deflection rollers, where a respective drive is attached to each axle in order to separately/independently drive each conveyor belt using the drive wheel and drive associated with that drive axle. Current race track conveyors have a significant drawback in that the conveyor belt that is driven by the axle disposed at the beginning of the transport path is operated in a pushing manner, which is unfavorable from a perspective of drive technology, in particular driving belts having long transport distances. The arrangement of three axles for three race tracks leads to an angle of wrap of only 90° for at least one axle. This brings about the drawback or reducing the number of teeth which engage the belt at the drive roller and, thereby, either limits the transfer of power to the belt or requires an increase in the diameter of the drive roller. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to provide a race track conveyor for a packaging facility that does not have the drawbacks mentioned above. 
     The race track conveyor according to the invention may comprise at least two, preferably at least three, conveyor belts and may have a separate drive for each conveyor belt. All drives may be arranged at the end of the race track conveyor in a direction of transport to drive all conveyor belts in a pulling manner and to allow for the use of driving pulleys having small diameters and an angle of wrap around the belt pulleys of almost 180° despite high drive performance. This allows the race track conveyor to have a low-profile design and reduces the costs to manufacture. 
     One embodiment may be particularly space-saving, wherein at least one drive wheel or belt pulley may be provided for each conveyor belt, and where the drive wheels or belt pulleys of several or all conveyor belts may be rotatable about a common axis of rotation. This common axis of rotation may be a deflection axle of the conveyor belts at the downstream end of the race track conveyor. 
     Preferably, two belts are provided for each conveyor belt in order to be able to process a plurality of tracks with products and thereby enhance performance. The two belts of each conveyor belt are preferably disposed on the right and the left of the track of products on this embodiment of the conveyor belt. 
     In this, it may be particularly advantageous if an angle of wrap of the belts of the conveyor belts on all driven belt pulleys is at least 160°, preferably at least 170°, or almost 180° to transmit high drive power at the smallest possible diameters of the belt pulleys. Additional tension rollers are not to be interpreted as being belt pulleys within the meaning of the present invention. 
     A first format at the time of reception of products on the race track conveyor may preferably have a number of tracks and/or rows that differs from a second format at the time of removal of products from the race track conveyor. The race track conveyor may be configured to perform a format change during transportation of the products, i.e., to change the spatial arrangement of the products of the format. A group of products that is placed on the race track conveyor may differ in format from a group of products that is removed from the race track conveyor. 
     In a particularly advantageous embodiment, a load capacity of one respective conveyor belt may correspond to a multiple of both the first and the second format. 
     Each race track conveyor may preferably comprise two belts which are connected to advance bars, the advance bars being oriented transversely to the direction of transport. The advance bars may assume the function of pushing or transporting the products, respectively. 
     A gear device may be preferably provided for at least one of the at least two conveyor belts between the drive and the belt pulleys in order to be able to drive two belts of each one conveyor belt with one drive. The gear device may be preferably a toothed belt gear with toothed belts. 
     A packaging facility according to the invention may comprise a packaging machine, preferably a thermoforming packaging machine, and an embodiment of the present race track conveyor. 
     In a particularly advantageous embodiment, the race track conveyor may be disposed downstream of the packaging machine to supply separated packages for further processing. This configuration provides the ability to perform a format change from the format created by the packaging machine (corresponding to a group of packages) to a required other format depending on the device downstream of the race track conveyor. In this, the packaging machine and the downstream device may have different work cycles. 
     Preferably, a first and a second transfer device may be provided at the race track conveyor in order to receive separated packages onto the race track conveyor as well as to again transfer them to a downstream device, both in a fully automated manner. The transfer devices preferably comprise at least one robot that can be configured, for example, as a two-axle robot or as a delta robot. 
     A design of the race track conveyor may also be conceivable in which the packages may also laterally approach (move towards) each other during the movement in the direction of transport, for example, in order to save volume for downstream carton loading as the final packaging. 
     Other aspects and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments and the accompanying drawing figures. 
    
    
     
       DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
       The accompanying drawings form a part of the specification and are to be read in conjunction therewith, in which like reference numerals are employed to indicate like or similar parts in the various views. 
         FIG. 1  is a schematic side view of a prior art triple belt conveyor; 
         FIG. 2  is a schematic side view of one embodiment of a race track conveyor as a triple belt conveyor in accordance with the teachings of the present invention; 
         FIG. 3   a  is a schematic top plan view of one embodiment of a race track conveyor as a triple belt conveyor in accordance with the teachings of the present invention; 
         FIG. 3   b  is a schematic sectional side view onto a respective one belt in the race track conveyor of  FIG. 3   a;    
         FIG. 4  is a top perspective view of one embodiment of a race track conveyor in accordance with the teachings of the present invention; 
         FIG. 5  is a top perspective view of one embodiment of a drive unit of the race track conveyor of  FIG. 4 ; and 
         FIG. 6  is a schematic view of a packaging facility including one embodiment of a race track conveyor in accordance with the teachings of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following detailed description of the present invention references the accompanying drawing figures that illustrate specific embodiments in which the invention can be practiced. The embodiments are intended to describe aspects of the present 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 spirit and scope of the present invention. The present invention is defined by the appended claims and, therefore, the description is not to be taken in a limiting sense and shall not limit the scope of equivalents to which such claims are entitled. 
       FIG. 1  shows a triple belt conveyor  1  according to prior art in a side view. The triple belt conveyor  1  is configured to transport products in a direction of transport T. Three conveyor belts  2 ,  3 ,  4  are provided that are arranged in the drawing plane one behind the other. A first conveyor belt  2  is driven at a first axle  5  that is provided at the front end of the triple belt conveyor  1 , the first axle  5  being driven by a first drive  6 , for example, a servo motor. The second conveyor belt  3  is driven at a second axle  7  that provided at the rear end of the triple belt conveyor  1 , the second axle  7  being driven by a second drive  8 . The third conveyor belt  4  is driven at a third axle  9  disposed below the second axle  7  by a third drive  10 . All three conveyor belts  2 ,  3 ,  4  are therefore driven independently of one another, where only the second  3  and the third  4  conveyor belt are operated in a pulling manner. The first conveyor belt  2  is operated in a pushing manner. The angle of wrap β, at which the second conveyor belt  3  is driven via a belt pulley  11  on the second axle  7  by drive  8 , is 90°. The angle of wrap β of the third conveyor belt  3  on a further belt pulley  12  is only slightly greater, and the angle of wrap β of the first conveyor belt  2  at a front belt pulley  13  is significantly smaller than 180°. 
     In direct comparison to  FIG. 1 ,  FIG. 2  shows a race track conveyor  20  according to one embodiment of the invention being provided with only two axles  21 ,  22 . Only deflection wheels  19  for belts  26 ,  27 ,  28  of conveyor belts  2 ,  3 ,  4  are provided on the axle  21  disposed at the beginning of the race track conveyor  20  located at the right as shown. The belt pulleys  23 ,  24 ,  25  for driving belts  26 ,  27 ,  28  of the three conveyor belts  2 ,  3 ,  4  are all arranged in the direction of transport T at the downstream end of the race track conveyor  29 . The embodiment of the respective drives is shown in more detail in  FIG. 5 . In contrast to the prior art shown in  FIG. 1 , it can be clearly seen in  FIG. 2  that by arranging only two axles  21 ,  22 , the angles of wrap (β) are uniformly 180° thereby enabling smaller diameters of wheels and pulleys while having the same power transmission. The space required to house the conveyor is also reduced. 
     The mode of operation of the race track conveyor  20  shall be explained with reference to  FIGS. 3   a  and  3   b .  FIG. 3   a  schematically in plan view shows the first conveyor belt  2  and the second conveyor belt  3 , where conveyor belts  2 ,  3  each comprise two belts  26   a ,  26   b ,  27   a ,  27   b , which are respectively jointly driven. Accordingly, the third conveyor belt  4  also comprises two belts  28   a ,  28   b . It is shown in the example of the first conveyor belt  2  that the belts  26   a ,  26   b  on their outer side comprise a group of entraining members  29  (see  FIG. 3   b ) being spaced at a regular distance from each other. Products  31 , such as packages, can be transported using advance bars  30  which are aligned perpendicular to the direction of transport T and are attached onto entraining members  29  (see  FIG. 3   b ) of both belts  26   a ,  26   b . The advance bars  30  push a group of products  31  in the direction of transport T after they have been loaded at the front end of the race track conveyor  20 . The group of products  31  of each one conveyor belt  2 ,  3 ,  4  is defined as the load capacity. 
       FIG. 3   b  shows the second conveyor belt  3  in a loading position for receiving the products  31  in a first format F 1  from a robot  32 . The first conveyor belt  2  is meanwhile in a discharge position for removing the product  31  from the race track conveyor  20  in which a further robot  33  collects the products  31  in a second format F 2 . The third conveyor belt  4  is performing a movement in the direction towards the loading position. During the advance movement, the products  31  may rest with their underside on a transport plane E. 
       FIG. 4  shows a schematic partial view of an eight-track race track conveyor  20  with two belts  26   a ,  26   b  for a first conveyor belt  2  and two belts  27   a ,  27   b  for a second conveyor belt  3 . Both belts  26   a ,  26   b ,  27   a ,  27   b  of the respective conveyor belt  2 ,  3  are each connected to six advance bars  30  which together transport a load capacity “A” of 48 or 8×6 products  31 , respectively, as a common format. Tracks S of a format in the direction of transport T and rows R of a format are aligned orthogonally thereto. A “format” is formed from a group of products  31  in “n” tracks and “m” rows, where “n” and “m” are integers. Any number of tracks S and rows R is presently conceivable and thereby a variety of formats or loading capacities A, respectively. For better illustration of the conveyor belts  2 ,  3 , the belts  26   a ,  26   b ,  27   a ,  27   b  are shown only in the region of the advance bars  30 . Guides are also conceivable which are aligned in the direction of transport for guiding the products  31  in the respective track S. In this, adjacent tracks S can approach each other to reduce lateral spacing between adjacent products  31  (see  FIGS. 3   a  and  3   b ). For example, an overlap of respectively designed packages  31  can be created which are loaded in this position into a carton by another robot  33  (see  FIG. 3   b ). 
       FIG. 5  shows the arrangement of three drives  6 ,  8 ,  10  for the three conveyor belts  2 ,  3 ,  4 , respectively. All driven belt pulleys  23   a ,  23   b ,  24   a ,  24   b ,  25   a ,  25   b  are arranged on the second axle  22 . The two belt pulleys  25   a ,  25   b  for the third conveyor belt  4  are fixed onto the second axle  22  in a rotationally fixed manner and axle  22  is driven by the third drive  10 . The further belt pulleys  23   a ,  23   b ,  24   a ,  24   b  are rotatably mounted on the second axle  22 . The first drive  6  comprises a gear device, preferably a toothed belt gear, and drives a third axle  7  onto which two belt pulleys  6   a  are fixed that drive two further gear belt pulleys  6   a  via an intermediate belt  6   b . In this, these gear belt pulleys  6   a  are with the belt pulleys  23   a ,  23   b  for the first conveyor belt  2  fixedly connected to each other. 
     Similarly thereto, the second drive  8  drives a fourth axle  9  onto which two gear belt pulleys  8   a  are fixed that drive two further gear belt pulleys  8   a  via an intermediate belt  8   b , preferably a toothed belt. In this, these gear belt pulleys  8   a  are with the belt pulleys  25   a ,  25   b  for the second conveyor belt  3  fixedly connected to each other. A gear device therefore comprises two gear belt pulleys  6   a  or  8   a , respectively, and a toothed belt, and in this embodiment is a toothed belt gear. 
     This design ensures that all three conveyor belts  2 ,  3 ,  4  are driven in a pulling manner at the end of the race track conveyor  20  thereby enabling a design with belt pulleys having small diameters and an angle of wrap β of 180° Similarly, two, four or more conveyor belts can in this manner be realized and are comprised by the invention. As shown in  FIG. 2 , the belts  26   a ,  26   b ,  27   a ,  27   b ,  28   a ,  28   b  are deflected by individual deflection rollers  19  at an axle  21  which is arranged at the beginning of the race track conveyor  20 . Belt tensioning can be performed by the deflection rollers  19  or by other known tension rollers provided. All belts are in this embodiment rotatable about the same axis of rotation  22 . 
       FIG. 6  shows a packaging facility  40  according to the invention comprising a thermo-forming packaging machine  41 , a first transfer device  42 , the race track conveyor  20  and a second transfer device  43 . The mode of operation of the packaging facility  40  shall below be illustrated in more detail. 
     The intermittently operating thermoforming packaging machine  40  in a forming station  41  forms trays  41   a  into a film web B. Products are loaded into these trays and in a sealing station  41   b  sealed with a further film web and in a cutting station  41   c  separated such that a first format F 1  or a group of packages  31 , respectively, is provided in every work cycle at the end of the thermoforming packaging machine  40  for the first transfer device. A format is composed, for example, of eight rows R and eight tracks S and thereby of sixty-four packages  31  (see  FIG. 3   b ) which are transferred by one or more robots  32  (see  FIG. 3   b ) of the first transfer device  42  onto a first conveyor belt  2  (see  FIGS. 3   a  and  3   b ). Each conveyor belt  2 ,  3 ,  4  of the race track conveyor  20  in this example has a loading capacity A of forty rows and eight tracks, and thereby of three hundred and twenty packages. Once the first conveyor belt  2  is completely filled with products  31  after several work cycles of the thermoforming packaging machine  41  and multiple transfers  31  of the packages from the thermoforming packaging machine  41  to the race track conveyor  20 , conveyor belt  2  is moved by the first drive  6  to the end of the race track conveyor  20 . 
     The packages  31  are there collected by the second transfer device  43  and loaded, for example, into a carton. As shown in  FIGS. 3   a  and  3   b , since the second format F 2  of a carton can comprise five rows R and eight tracks S, the second transfer device  43  operates in a work cycle differing from the first transfer device  42 . While the second transfer device  43  removes packages  31  of the first conveyor belt  2 , the first transfer device  42  can remove packages  31  newly produced by the thermoforming packaging machine  41  and load them onto the second conveyor belt  3 . The third conveyor belt  4  without packages is meanwhile on its way back from the second transfer device  43  to the first transfer device  42 . Such an arrangement allows continuous operation of the packaging facility  40  despite differing formats F 1 , F 2 , which are on the one hand provided by the thermoforming packaging machine  41  and are on the other hand the format desired for the packages  31  to be finally packed into the carton. This can achieve maximum performance and use to capacity of the individual facility components, in particular of the robots of the transfer devices  42 ,  43 . 
     Another embodiment is also conceivable in which a race track conveyor  20  may be disposed along a loading stretch of a thermoforming packaging machine  41  in order to load products with a transfer device from the race track conveyor  20  into the thermoforming packaging machine  41  or into the trays, respectively. 
     As is evident from the foregoing description, certain aspects of the present invention are not limited to the particular details of the examples illustrated herein. It is therefore contemplated that other modifications and applications using other similar or related features or techniques will occur to those skilled in the art. It is accordingly intended that all such modifications, variations, and other uses and applications which do not depart from the spirit and scope of the present invention are deemed to be covered by the present invention. 
     Other aspects, objects, and advantages of the present invention can be obtained from a study of the drawings, the disclosures, and the appended claims.