Abstract:
A multi-modal package handling tool and system uses a robot carrying an end of arm tool incorporating several package handling devices such as vacuum carrying units, extensible package grippers, and a slideably deployable package platform. Each these package handling devices may be used singly, or in combination with each other.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a tool which may be mounted upon a prime mover, such an industrial robot, for the purpose of handling a variety of different size and shape packages, such as those commonly used for consumer and pre-consumer packaging of various beverages.  
         [0003]     2. Disclosure Information  
         [0004]     The distribution of various packages of food items, particularly beverages, is rendered more difficult by the fact that beverage containers come in a variety of sizes and shapes. For example, beverages are marketed in 12 ounce cans, one liter bottles, smaller bottles, and larger containers having all sorts of sizes and shapes. Moreover, the packages used to hold such beverage containers come in a scarcely fewer number of sizes and shapes. It is often necessary for beverage distributors to break down pallets or subdivide pallets of beverages at a distribution point, because frequently the beverage retailer whose order is being filled does not desire to take delivery of a full pallet of one particular type of beverage. Thus, a full pallet having but one type of beverage packaged in a single type of package, will need to be broken down. Unfortunately, use of picker and packer employees to handle such packages results in considerable expense for labor.  
         [0005]     The present invention uses an end of arm tool mounted on a robot, with the robot preferably mounted on a track, to pick a variety of different types of packages, for the purpose of loading the packages on a pallet for shipment to, for example, a retailer of packaged goods.  
       SUMMARY OF THE INVENTION  
       [0006]     The present multi-modal package handling tool includes a tool platform with a plurality of package-carrying vacuum units arranged in a generally planar array, with the vacuum units being attached to a first portion of the tool platform. A plurality of extensible package grippers is mounted to the tool platform, with extensible grippers having at least a retracted position and an extended position. The tool platform may also have a slidingly deployable package platform mounted thereto, with the package platform having at least a retracted position and an extended position.  
         [0007]     Each of the vacuum units mounted to the tool platform has a vacuum head powered by a dedicated vacuum generator. This offers the advantage that in the event that a vacuum leak occurs within any of the vacuum units, vacuum to will not be lost with respect to the remaining units because each of the vacuum heads has an independent source of vacuum. Moreover minor air leaks will not cause the vacuum power of any of the vacuum heads to be lost. Each of the vacuum heads extends through a port formed in a surface plate which is also attached to the tool platform, such that a package engaged by one or more of the vacuum heads will be drawn into contact with the surface plate. This advantageous result occurs because the vacuum units contract axially when the vacuum is applied and this causes the package being secured by the vacuum units to be pulled into contact with the surface plate, thereby stabilizing the package being carried.  
         [0008]     Each of the previously mentioned extensible grippers comprises a package engaging tool mounted to the tool platform by means of a slidable carrier. The extensible grippers may include either hook-like members for engaging handholds formed in a tray of goods, or pincher members for engaging a tray of goods, whether the tray be of cardboard, plastics, metal, or other materials known to those skilled in the art and suggested by this disclosure.  
         [0009]     Smooth-sided packages, such as closed cardboard cartons may be picked by the plurality of package-carrying vacuum units which are arranged in a generally planar array at one end of a space frame comprising the tool platform. Package grippers are mounted within space frame adjacent to the generally planar array, with the package grippers having at least a retracted position inboard of the planar array and extended position outboard of the planar array. Similarly, the package platform has at least a retracted position inboard of the planar array and an extended position outboard of the planar array.  
         [0010]     According to another aspect of the present invention, a machine vision unit is operatively connected with a controller which operates not only the robot to which the end of arm tool is attached, but also the vacuum units, package grippers, and sliding package platform. Using techniques which are known to those skilled in the art and beyond the scope of this inventions, the machine vision unit provides the controller with an image of a package being handled, so as to permit the controller to select the use of either the vacuum units or package grippers or a combination of the vacuum units and the package platform. In the event that both the package platform and the vacuum units are used, the end of arm tool will be oriented such that the surface plate through which the vacuum units erupt will be situated in a generally vertical orientation, with the sequence of attaching the package to the end of arm tool following the steps of using the vacuum units and the robot to lift the package while deploying the sliding package platform under the lifted package. In this manner, the sliding package platform may be positioned under the package without pushing the package from its position on a supply pallet.  
         [0011]     According to another aspect of the present invention, a method for picking up a package includes the steps of determining at least one characteristic of a package being picked up, communicating the determined characteristic to a controller, and using the controller to select from a plurality of package attachment systems carried upon an end of arm tool, with the controller making the selection based upon the previously described characteristic. Then, at least one selected package attachment system is presented to a package by means of a robot having the end of arm tool attached thereto, with the robot being operated by the controller. The ultimate step is attachment of the package to the end of arm tool by means of the selected package attachment system.  
         [0012]     It is an advantage of the present invention that a single end of arm tool may accommodate a large number of packages having different sizes, shapes, construction and configuration, ranging from plastic trays having multiple packages of bottles contained therein, to smooth sided cardboard or plastic packages, to cardboard tray packages.  
         [0013]     It is a further advantage of the present invention that this invention allows the breaking down of homogeneous package pallets into mixed pallets without the need for human operators.  
         [0014]     Other advantages, as well as features and objects of the present invention will become apparent to the reader of this specification. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]      FIG. 1  is a perspective view of a multi-modal package handling system according to the present invention.  
         [0016]      FIG. 2  is a perspective view of a portion of the system in  FIG. 1 , showing the present handling system picking up a smooth-sided cardboard carton.  
         [0017]      FIG. 3  is a segment of the illustration of  FIG. 2 , albeit from a different perspective, showing additional design elements of an end of arm tool according to the present invention.  
         [0018]      FIG. 4  illustrates the present multi-modal package handling system picking up a tray of beverage bottles.  
         [0019]      FIG. 5  is an enlarged portion of  FIG. 4 , showing additional details of construction of the present end of arm tool.  
         [0020]      FIG. 6  is similar to  FIG. 5 , but depicts pincer type package grippers mounted to the end of arm tool.  
         [0021]      FIG. 7  is similar to  FIG. 1  but illustrates two end of arm tools mounted to a single robot arm.  
         [0022]      FIG. 8  is a block diagram of a portion of a control system according to one aspect of the present invention.  
         [0023]      FIG. 9  illustrates a multi-modal package pickup operation involving not only vacuum units, but also a sliding package platform. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0024]     As shown in  FIG. 1 , the present multi-modal package handling system is preferably used in conjunction with guideway  14 , which is situated between adjacent rows of supply pallets  20 . Robot  32  has robot arm  34 , to which multi-modal package handling tool  36  is mounted. In turn, robot  32  is mounted upon carriage  38 , which also transports shipping pallet  24 , which is ultimately filled with goods  26  removed from pallets  20 . System  10  traverses guideway  14 , picking various items or packages  26  from pallets  20 , depositing them on shipping pallet  24 . When shipping pallet  24  is full, pallet  24  is removed from carriage  38  and placed in line for transport from the storage facility.  
         [0025]      FIG. 2  shows certain details of a portion of a system according to present invention. Multi-modal package handling tool  36  includes end plates  46 , between which a four columns  48  are mounted. End plates  46  and columns  48  define a space frame to which various other components are mounted. The space frame is mounted to robot arm  34 .  FIG. 2  illustrates end of arm tool  36  picking up a smooth sided cardboard carton,  26 . This carton is being picked by means of vacuum units,  76 , which are described in greater detail later in this specification.  
         [0026]      FIG. 2  additionally shows slidingly deployable package platform  54 , which is mounted upon sliding mount  62 . Columns  48  each have a plurality of mortises  56  which are engaged by mount  62 . Slidingly deployable package platform  54  is positioned by means of cylinder  60 , which is has a fixed end mounted to the space frame defined by columns  48  and end plates  46 . Usage of sliding platform  54  is further described in connection with the discussion of  FIG. 9 .  FIG. 2  also shows gripper  70 , which is positioned by means of cylinder  72 . Gripper  70  is swung into deployment by means of a cylinder,  73 , which is shown with greater specificity in  FIG. 4 . Those skilled in the art will appreciate in view of this disclosure that, as used herein, the term “cylinder” means either a conventional pneumatic cylinder, or a hydraulic cylinder, or an electrically driven device, or yet other types of linear actuators used within various types of machinery.  
         [0027]      FIGS. 3 and 5  show the construction of surface plate  86 , which has a plurality of ports,  84 , formed therein. Each of vacuum units  76  includes a multi-ribbed cup which is fed vacuum by means of a dedicated vacuum generator,  82 . The present inventors have determined that a vacuum generator model VGS3010.AC.04.BH from the PIAB company is preferred for practicing the present invention. Vacuum generators  82  are shown with greater specificity in  FIG. 5 .  
         [0028]     When the multi-ribbed vacuum cups incorporated within vacuum devices  76  are activated by providing compressed air to vacuum generators  82 , the vacuum ribbed cups contract axially, causing the package being picked to be pulled up tightly to surface place  86 . This is shown specifically in  FIG. 2 . As noted above, each of vacuum generators  82  shown in  FIG. 5  is independently powered. In other words, compressed air is supplied to each of the vacuum generators  82 , but there is no manifolding for interconnecting the vacuum output side of vacuum generators  82 . Each vacuum generator  82  provides vacuum to a single vacuum unit  76 , and this is important because in the event that a vacuum cannot be pulled on any one or more of vacuum units  76 , vacuum may still be pulled on the remaining units.  
         [0029]     The drink bottles shown in  FIG. 5  are pulled up tightly against surface plate  86 , but this is due to the action of package grippers  70 , which pull upon tray  26  of  FIG. 5 . Vacuum units  76  are normally not employed to pick bottles such as those illustrated in  FIG. 5 .  FIG. 6  is similar to  FIG. 5 , but shows a pincer,  90 , which is used in a plurality of locations similar to the locations used with respect to package grippers  70 . Pincers  90  are particularly useful for gripping cardboard shipping trays, either at the ends of such trays, or in certain cases, at the center of the tray. Pincers  90  may be actuated either by hydraulic or pneumatic cylinders, or by other types of linear force/motion devices known to those skilled in the art and suggested by this disclosure. The application of such devices is beyond the scope of this specification.  
         [0030]      FIG. 7  is similar to  FIG. 1 , but shows two end of arm tools  36  mounted on a single robot arm  34 . This configuration may be pursued in an effort to increase the throughput of a system according to the present invention.  
         [0031]      FIG. 8  is a block diagram according to present invention, and shows controller  100  as receiving inputs from sensors  102 . A variety of different sensors such as regular, low light, or infrared cameras, radio frequency tagging, or other types of devices known to those skilled in the art and suggested by this disclosure may be employed for the purpose of determining a characteristic of the package being picked. This characteristic may, for example, be the amount of open area in the top surface of the package, which would indicated whether the package is a tray of bottles having a large amount of open area, or a smooth cardboard carton having little or no open areas. In any event, inputs from various sensors  1  of  2  are used by controller  100  to selectively operate vacuum units  76 , robot  32 , package grippers  70 , and sliding platform  54  to pick a package having a detected characteristic.  
         [0032]      FIG. 9  illustrates another multi-modal function according to the present invention in which end of arm tool  36  picks a package from one side by first attaching to the side of package  26  with at least one vacuum unit  76 . Then, package  26  will be lifted by robot  32  so that cylinder  60  is able to extend slidingly deployable package platform  54  under package  26  without pushing package  26  from its immediately previous location.  
         [0033]     Although the present invention has been described in connection with particular embodiments thereof, it is to be understood that various modifications, alterations, and adaptations may be made by those skilled in the art without departing from the spirit and scope of the invention set forth in the following claims.