Abstract:
A “pick-and-place” package marshalling system uses multiple pneumatic transfer units synchronized with a packaging conveyor to marshal packets into a single-file array for shipping and to cull out empty and defective packets. The system can be employed in a blister packaging operation in place of a standard marshalling system. A pick-and-place module, comprising one or more pairs of pneumatic transfer units, lifts packets off the conveyor at a pick station, marshalls them into a single-file array, carries the packets above the conveyor to a downstream place station, and pneumatically deposits the packets there.

Description:
REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of the filing date of Provisional Patent Application No. 61/663,963, filed Jun. 25, 2012. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to the field of devices and methods for marshalling packaged products, and more particularly to systems for marshalling small packages, such as blister-packaged pharmaceuticals. 
     Pharmaceutical tablets and pills are often individually packaged in formed plastic “blisters,” which are sealed with a foil backing. In order to expedite the packaging process, blister packets are formed, filled and sealed in multiple laterally-disposed lanes.  FIG. 1  is a schematic diagram of a standard blister packaging process, comprising a forming station  101 , a feeding station  102 , a vision station  103 , a sealing station  104 , a punching station  105 , a transfer station  114  and marshalling station  106 . 
     Blisters are formed out of a continuous web  108  of plastic material at the forming station  101 . Blisters are filled with the appropriate quantity of product at the feeding station  102 , and the blisters are sealed at the sealing station  104 , using a continuous sheet of foil material. The web  108  is controlled by an indexing station  115 , which moves stepwise with an established index distance  109 . Between the feeding station  102  and the sealing station  104 , a vision station  103  determines whether the appropriate quantity of product is present in each packet and whether there is any defective product. At the punching station  105 , individual packets  107  are punched out of the continuous formed and sealed web  108 . Through the punching station  105  the packets  107  are transferred at the transfer station  114  downstream to the marshalling station  106 . The longitudinal centerline of the web  108  establishes the web axis  110 . Each of the packets  107  has a longitudinal packet axis  111 , which is parallel to the web axis  110 . 
     Individual packets  107  are typically punched out in an in-line array  112  at the punching station  105 , as shown in  FIG. 1 . For convenience, we will refer to them as packets #1, #2, #3 and #4. 
     At the transfer station  114 , defective packets are rejected and only the non-defective packets are transferred in a multi-lane array to the marshalling station  106 . The reject verification station  116 —comprising an array of photo-sensors connected to the vision station  103  through the machine processor—ensure that all the packets  107  being transferred are in good condition and filled with the right amount of products. If a non-defective packet is rejected or a defective packet is transferred, the reject verification station  116  sends a signal to the processor and the machine automatically stops. In this way, the machine operator can recover the non-defective packet or remove the defective packet from the line. 
     At the transfer station  114 , after defective packets are removed, the in-line array  112  of packets  107  is transferred to a marshaling station  106 , where it is rearranged in a pattern amenable to stacking in a shipping container—which is typically a single-file arrangement. In prior art marshalling systems currently in use in the pharmaceutical packaging industry, the multi-lane packet pattern  117  is merged into a single file  118  by converging guide rails  113 , as depicted in  FIG. 1 . This system has the distinct disadvantage, however, that packets—particularly those that are small and lightweight—will often flip over when they contact the guide rail  113  and jam up the marshalling process. 
     The present invention addresses this problem by providing a “pick &amp; place” marshalling system, which performs the functions of: (a) rejecting empty and defective packets, (b) rearranging the staggered packet array into a single file, and (c) transferring the non-empty, non-defective packets from the indexed conveyor to a single-file marshalling conveyor, which ultimately empties into a shipping container, and (d) making sure that only the non-empty, non-defective packages are transferred and only the empty and defective packages are rejected. 
     SUMMARY OF THE INVENTION 
     The “pick-and-place” blister packet marshalling system of the present invention comprises a pick-and-place module operating along a packet conveyor between a pick station and a place station. The pick-and-place module communicates electronically with an upstream packet sensor and central processing unit. The pick-and-place module comprises one or more pairs of pneumatic transfer units, which pneumatically lift the packets off the conveyor at the pick station, marshall the packets into a single-file array, carry the packets downstream above the conveyor to the place station, and pneumatically deposit the packets in the single-file array at the place station. From the place station, the packets are carried by a single-file marshalling conveyor to a shipping container. 
     The timing of the system&#39;s operations at the pick station and the place station is synchronized with the motion of the conveyor by the central processing unit. The packet sensor identifies packets that are either empty or filled with defective product. The sensor signals the pneumatic transfer units to bypass the empty packets, so that the conveyor carries them into a first reject receptacle, and to deposit the defective parcels in a second reject receptacle. Alternately, the sensor can signal the module to bypass the defective parcels to the first reject receptacle and deposit the empty parcels in the second reject receptacle. 
     The marshalling of the packets into a single-file array is performed by the pick-and-place module by differentially displacing the packets to that they align with the central longitudinal conveyor axis. Pairs of distal packets, which are farther removed from the conveyor axis, are given a greater displacement by the pneumatic transfer units, while pairs of proximal packets, which are closer to the conveyor axis, are given a lesser displacement. 
     The foregoing summarizes the general design features of the present invention. In the following sections, a specific embodiment of the present invention will be described in some detail. This specific embodiment is intended to demonstrate the feasibility of implementing the present invention in accordance with the general design features discussed above. Therefore, the detailed description of this embodiment is offered for illustrative and exemplary purposes only, and it is not intended to limit the scope either of the foregoing summary description or of the claims which follow. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of a standard prior art blister packaging process; 
         FIG. 2A  is a schematic diagram of the blister packaging process of the present invention; 
         FIG. 2B  is a top plan view of the blister packaging process of the present invention; 
         FIG. 2C  is side profile view of the blister packaging process of the present invention; 
         FIG. 3A  is a perspective view of a pneumatic transfer unit of the preferred embodiment of the present invention in the “pick” position; 
         FIG. 3B  is a front profile view of a pneumatic transfer unit of the preferred embodiment of the present invention in the “pick” position; 
         FIG. 3C  is a side profile view of a pneumatic transfer unit of the preferred embodiment of the present invention in the “pick” position; 
         FIG. 3D  is a top plan view of a pneumatic transfer unit of the preferred embodiment of the present invention in the “pick” position; 
         FIG. 4A  is a perspective view of a pneumatic transfer unit of the preferred embodiment of the present invention in the “place” position; 
         FIG. 4B  is a front profile view of a pneumatic transfer unit of the preferred embodiment of the present invention in the “place” position; 
         FIG. 4C  is a side profile view of a pneumatic transfer unit of the preferred embodiment of the present invention in the “place” position; 
         FIG. 4D  is a top plan view of a pneumatic transfer unit of the preferred embodiment of the present invention in the “place” position; 
         FIG. 5A  is a side profile view of a pick-and-place module of the preferred embodiment of the present invention in the “pick” position; 
         FIG. 5B  is a top plan view of a pick-and-place module of the preferred embodiment of the present invention in the “pick” position; 
         FIG. 5C  is a side profile view of a pick-and-place module of the preferred embodiment of the present invention in the inline marshalling position; 
         FIG. 5D  is a top plan view of a pick-and-place module of the preferred embodiment of the present invention in the inline marshalling position; 
         FIG. 5E  is a side profile view of a pick-and-place module of the preferred embodiment of the present invention in the “place” position; and 
         FIG. 5F  is a perspective view of a pick-and-place module of the preferred embodiment of the present invention in the “place” position. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As shown schematically in  FIG. 2A , the pick-and-place marshalling system of the present invention performs downstream of a forming station  201 , a feeding station  202 , a vision station  203 , a sealing station  204  and a punching station  205 , similar to the standard prior art transferring and marshalling system depicted in  FIG. 1 . In the present invention, however, the standard transfer ( FIG. 1 ,  114 ), reject verification ( FIG. 1 ,  116 ) and marshalling stations ( FIG. 1 ,  106 ) are replaced by a compact pick-and-place module  200  capable of rejecting, controlling, marshalling and transferring all together. The pick-and-place module  200  comprises multiple pneumatic transfer units  270 , and it operates between a pick station  206  and a place station  207 . The pick station  206  has a pick centerline  208 , which aligns perpendicular to the longitudinal axis  209  of the conveyor  210 . Contrary to the prior art, the individual packets  211  emerge from the punching station  205  in a multi-lane staggered array  212 . The staggered array  212  has a transverse array midpoint  213  that is parallel to the pick centerline  208 . In the example depicted in  FIG. 2A , the array midpoint  213  is located between packet # 2  and packet # 3  and makes a right angle with the conveyor axis  209 . 
     The continuous or indexed stepwise movement of the conveyor  210  and the pick-and-place module  200  are synchronized: when the array midpoint  213  coincides with the pick centerline  208 , a programmable system processor activates a plurality of pneumatic transfer units  270 , as depicted in  FIG. 2B . The pneumatic transfer units  270  contain multiple vacuum cylinders  215 , as shown in  FIG. 2C , which engage each of the packets  211  that have not been detected as empty by the upstream vision system  203 . 
     As depicted in  FIGS. 3A-C  and  4 A-C, each of the vacuum cylinders  215  has a telescoping distal end  216  terminating in a suction cup  217 . The proximal end  218  of each vacuum cylinder  215  comprises a plenum  219 , into which either pressurized air or a partial vacuum is introduced through an air hose  226  by the action of a solenoid valve  220  (see  FIGS. 5B , D and F). As shown in  FIGS. 3A-B , at the pick station  206 , each of the activated vacuum cylinders  215  is in the vacuum mode, such that, upon its suction cup  217  engaging a packet  211 , negative vacuum pressure causes the telescoping distal end  216  to retract upward, thereby lifting the packet  211  up off the conveyor  210 . 
     Once lifted from the conveyor  210  at the pick center line  208 , each of the packets  211  is displaced by the pneumatic transfer units  270  so that its longitudinal packet axis  221  aligns with the longitudinal conveyor axis  209 . As depicted in  FIG. 2A , the centripetal displacement of the packets  211  is symmetrical about the conveyor axis  209 . The distal packets  222 , i.e., those in the lanes furthest from the conveyor axis  209 —in this example packet #1 and packet #4—are given a greater displacement d 1 . The proximal packets  223 , i.e., those in the lanes closest to the conveyor axis  209 —in this example packet #2 and packet #3—are given a lesser displacement d 2 . As shown in  FIG. 3D , the vacuum cylinders  215  that engage and lift the distal packets  222  are designated as distal vacuum cylinders  224 , while those that engage and lift proximal packets  223  are proximal vacuum cylinders  225 . 
     This differential centripetal displacement is accomplished by a series of paired, oppositely disposed pneumatically driven pusher rods  230  in the pneumatic transfer unit  270 , as depicted in  FIGS. 3A-D  and  4 A-D. The distal end  231  of each pusher rod  230  is attached to a pusher bar  232 , which slides along an upper guide rail  233 . The pusher bar  232  has an outer side  234  and an inner side  235 . The outer side  234  of the pusher bar  232  is directly connected to one of the distal vacuum cylinders  224 , while the inner side  235  comprises two pusher flanges  236 , a rear pusher flange  237  and a forward pusher flange  238 , which alternately engage a slide block  239  attached to one of the proximal vacuum cylinders  225 . The slide block  239  slides along a lower guide rail  240 , between a forward stop  241  and a rear stop  242 . 
     The extension of each pusher rod  230  is controlled by a pneumatic cylinder  243 , to which compressed air is applied by a secondary solenoid valve  244  (see  FIG. 5F ). In the “pick” position  206 , as depicted in  FIGS. 3A-D , the pneumatic cylinder  243  is pressurized, the pusher rod  230  is fully extended, and it pushes the pusher bar  232  to the distal end of the upper guide rail  233 . In this extended position, the distal vacuum cylinder  224  connected to the outer side  234  of the pusher bar  232  is at the greater displacement d 1  from the conveyor axis  209 . In this extended position, the forward pusher flange  238  on the inner side  235  of the pusher bar  232  engages the slide block  239  to which the proximal vacuum cylinder  225  is attached and forces it against the forward stop  241 . At this point, the proximal vacuum cylinder  225  is at the lesser displacement d 2  from the conveyor axis  209 . 
     In the “place” position, as depicted in  FIGS. 4A-D , compressed air is applied to the pneumatic cylinder  243  by the secondary solenoid valve  244 , the pusher rod  230  is fully refracted, and it pulls the pusher bar  232  to the proximal end of the upper guide rail  233 . In this refracted position, the distal vacuum cylinder  224  on the outer side  234  of the pusher bar  232  is moved into alignment with the conveyor axis  209 . Simultaneously, the rear pusher flange  237  on the inner side  235  of the pusher bar  232  engages the slide block  239  to which the proximal vacuum cylinder  225  is attached on the inner side  235  of the pusher bar  232  and forces it against the rear stop  242 , which it is aligned with the conveyor axis  209 . 
     As shown in  FIGS. 5A-F , each pick-and-place module  200  comprises a pair of opposing pneumatic transfer units  270  with opposing pneumatic cylinders  243  having cooperating oppositely-disposed pusher rods  230 . A first pusher rod  255  controls the centripetal displacement of the leading vacuum cylinders  256 , which lift packets #1 and #2 in this example. A second pusher rod  257  controls the oppositely-directed centripetal displacement of the trailing vacuum cylinders  258 , which in this example lift packets #3 and #4. 
     Referring to  FIG. 2A-C , once marshalling of the packets  211  in line with the conveyor axis  209  is completed, the pick-and-place module  200  as a whole, with the lifted packets  211  attached to the vacuum cylinders  215 , shifts upstream from the pick centerline  208 , transferring the packets/blisters to the place centerline  227 . The inline packet array  228  is positioned with its midpoint aligned with the place centerline  227 , and the telescoping distal ends  216  of the vacuum cylinders  215  are lowered. The primary solenoid valves  220  switch the feed to the vacuum cylinder air hoses  226  from vacuum to compressed air, thereby causing the lifted packets  211  to be released from the suction cups  217  of the vacuum cylinders  215  and placed onto the marshalling conveyor  229 . 
     As for the non-filled/empty packets which are identified by the vision system  203 , since these are not picked up from the indexed conveyor  210 , they continue to travel to the end of the conveyor  210  and fall into a designated empty packet receptacle  259 . The defective and/or improperly filled packets containing product are considered medical waste, therefore they cannot be mixed with empty packets/blisters. The defective and/or improperly filled packets are lifted by the pneumatic transfer units  270  at the pick center line  208 , and rejected upstream into a designated reject packet receptacle  260  upstream of the place centerline  227 . 
     The reject verification, contrary to the prior art, is also included in the pick-and-place module  200 . As shown in  FIGS. 3A-B  and  4 A-B, each vacuum cylinder  215  has a reject control sensor  299 , attached to it. This sensor  299  detects if a defective or empty packet was transferred and/or a non-defective packet was rejected, and if so, it automatically stops the machine. 
     Although the preferred embodiment of the present invention has been disclosed for illustrative purposes, those skilled in the art will appreciate that many additions, modifications and substitutions are possible, without departing from the scope and spirit of the present invention as defined by the accompanying claims.