Abstract:
An apparatus and method is provided for loading objects having a first degree of hardness onto a tray having a different degree of hardness where sliding contact between the objects and the tray would cause damage. The tray loading is accomplished by engaging and holding objects in a carrier. The carrier carries the objects to a position over the tray and lowers the objects onto the tray surface, avoiding abrasion between the objects and the tray. The carrier includes sensors for verifying the presence of the objects.

Description:
FIELD OF THE INVENTION 
     The present invention relates to the field of packing equipment, and more particularly to equipment for placing pharmaceutical vials onto trays without sliding contact in order to avoid tray abrasion. 
     BACKGROUND OF THE INVENTION 
     For reasons of maintaining a sanitary environment for the manufacture of pharmaceutical products, processing and handling equipment have been traditionally made of stainless steel. As is well understood, stainless steel will not oxidize and may be cleaned repeatedly in an autoclave. Many pharmaceutical products, e.g. serums, vaccines, and other injectable medications are packaged in glass vials. The glass vials are typically sealed with a metal band holding an elastomeric membrane over the vial opening. 
     These glass vials are generally loaded onto stainless steel trays during the manufacturing process, e.g. for autoclaving, filling, or transporting. Depending on the stage of processing, the glass vials may be either empty or full when loaded onto trays. In all known tray loading machinery, the vials are pushed onto the trays causing the bottom of the vial to rub across the surface of the tray. It is well known that glass is very hard, on the order of 68-72 on the Rockwell C Hardness Scale. By comparison, stainless steel has a hardness of approximately 17 on the same scale, being much softer than glass. Therefore, rubbing glass on stainless steel will scratch the stainless steel surface and generate a fine particulate metallic dust. Federal Food And Drug Administration regulations prohibit any particulate in pharmaceutical clean environments as a potential source of contamination. With existing tray loading machinery this problem cannot be avoided and must be corrected by either periodically refinishing the tray surface or by replacing badly abraded trays. In addition to the danger of product contamination, tray remediation or replacement is expensive. In current pharmaceutical processing some equipment, e.g. handling trays, may be made of a plastic resin that can withstand the autoclaving process. Plastic resin will be readily scratched by abrasion with a glass vial being pushed over the plastic surface, in some cases producing unacceptable particulate. 
     An alternate type of equipment for loading parts into cartons or onto trays is known in the packaging industry. This loading equipment operates by engaging the bottle, box or other piece for packing from above, therefore exposing the top of the piece to contamination. Because of the potential for contamination, this equipment is not considered to be acceptable for use in loading pharmaceutical vials onto trays. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes the problems outlined above by providing a tray loader apparatus and method that places the vials on the trays effectively without rubbing or abrasion of the contacting surfaces. The tray loader of the invention simultaneously engages a number of vials at and below the level of the vial neck with no part overriding the top of the vials. The engaging vial carrier utilizes nesting fingers for holding the vials in a linear array, grasping components for ensuring that the vials do not disengage from the carrier, and sensors to verify that the proper number of vials are engaged and are delivered to the tray. The apparatus then lifts the vials and places the vials onto the surface of a tray. The tray loader disclosed is programmable to place the vials onto the trays in either rectilinear alignment or with successive rows of vials staggered to create a nested pattern. Programming counts the total number of vials loaded to signal when the instant tray is full. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention is best understood in conjunction with the accompanying drawing figures in which like elements are identified by similar reference numerals and wherein: 
         FIG. 1  is a schematic plan view of a tray conveyor and a vial conveyor with a tray loader apparatus of the invention with a vial carrier positioned for engaging a row of vials to be loaded onto a tray. 
         FIG. 2  is the plan view of  FIG. 1  wherein the tray loader apparatus has carried the vials into alignment with a tray being loaded. 
         FIG. 3  is the plan view of  FIG. 2  wherein the tray loader apparatus is holding the row of vials over the tray in position for placement. 
         FIG. 4  is the plan view of  FIG. 3  wherein the tray loader apparatus has placed the row of vials onto the tray and retreated to a position for moving laterally and engaging another row of vials. 
         FIG. 5  is an enlarged side elevation view of the carrier assembly for engaging and carrying vials. 
         FIG. 6  is a block diagram of the tray loader system of the invention. 
         FIG. 7  is a process listing of the method steps of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIG. 1 , a tray conveyor  10  is provided for conveying a series of trays  12 ,  12 ′ in the direction indicated by arrow A. A pair of side rails  14 ,  14 ′ are mounted adjacent to tray conveyor  10  to maintain trays  12 ,  12 ′ in linear alignment along a defined path. A tray locator  18  is movably mounted to be positioned across tray conveyor  10  as each new tray  12 ,  12 ′ is located for being loaded with vials. When first tray  12  is filled, tray locator  18  is moved out of position to allow tray  12  to move downstream and to bring second tray  12 ′ into position for loading. Additional trays (not shown) are serially loaded onto the upstream end of tray conveyor  10  by automated or manual means. Two rows of objects, for example vials  24 , are depicted as having previously been loaded onto tray  12 . Whereas the invention is described generally as an apparatus and method for loading vials onto trays, it is understood that loading any object having a first degree of hardness onto a tray having a different degree of hardness would benefit from the present invention. 
     Referring further to  FIG. 1 , a vial conveyor  20  is positioned adjacent to tray conveyor  10 , e.g. in parallel orientation thereto. A full row of vials  24  is positioned in vial conveyor  20  with the leading vial in contact with a fixed stop  26  to hold vials  24  in a positive location. In the illustrated embodiment of the present invention, a full row of vials  24  equals eighteen vials. Different numbers of vials per row is considered to be within the scope of the invention. A partial row of vials  24 ′ is held upstream in vial conveyor  20  by a controllable escapement  28 . The side rails of vial conveyor  20  are preferably separated by a distance sufficient to allow vials  24  to slide or be conveyed therebetween in substantially linear alignment. Vial conveyor  20  may optionally be a mechanically driven belt, a gravity fed chute, or another type conveyor for placing vials  24  in position for being engaged by vial carrier  34 . Whereas the diameter of each vial  24  is e.g. nominally 0.750 inches, manufacturing tolerances allow a difference of e.g. +/−0.010 inches. It is important to maintain a desired distance from the centerline of each vial to adjacent vials to avoid misalignment. Misalignment would result in vial carrier  34  rubbing against the neck of the off-center vials, possibly resulting in scratching or damage of the vial carrier. This rubbing and possible damage would likely produce particulate contaminate and necessitate repair or replacement of vial carrier parts. To minimize this problem, an alignment comb  32  is positioned adjacent to vial conveyor  20  and is brought into contact with vials  24  first, after which vial carrier  34  is brought into contact with vials  24 . Alignment comb  32  is formed as a planar member having a scalloped leading edge, each concavity of the scallop configured similar to the radius of the body portion of vial  24  and being an arc of less than 180°. Alignment comb  32  engages the exposed lower segment of vials  24  without interfering with contact between adjacent vials  24 . Alignment comb  32  is oriented at a slight angle K with relation to vial conveyor  20  and carrier  34  to capture vials  24  sequentially, thus allowing a low stress repositioning of the vials to the desired spacing. In this way, alignment comb  32  holds each vial  24  with its centerline at a position one nominal diameter from the centerline of the adjacent vials  24 . 
     Referring further to  FIG. 1 , a vial carrier  34  is positioned adjacent to vial conveyor  20  and juxtaposed to the full row of vials  24 . Carrier  34  is mounted to the outer end of an arm  30 , the inner end of arm  30  being operatively connected to a multi-axis driver mechanism, such as a multi-axis servo mechanical system (not shown). The servo system is operated by a microprocessor that is programmable through a human-machine interface as will be described below. The outer edge of carrier  34  (the left edge as illustrated) is configured as a linear array of fixed width scalloped cavities spaced a fixed distance from one another, each cavity configured for engaging the neck portion of a vial  24 . It is contemplated that the present invention tray loader may be used for loading different size vials by replacing a current vial carrier with a different vial carrier adapted to conform thereto. Arm  30  now moves in the direction indicated by arrow B, i.e. in the negative X direction according to the axis reference shown at the bottom right hand section of the drawing. This movement of arm  30  brings carrier  34  into engagement with the full row of vials  24  in a manner to contact the neck of each vial  24  and have no portion of carrier  34  above the top of vials  24 . When carrier  34  is in contact with vials  24 , a securing mechanism holds vials  24  in carrier  34  and a sensor array acts to confirm that each of the full row of vials  24  is in position, as will be described below. Arm  30  and carrier  34  next lift vials  24  out of vial conveyor  20  and move in the negative Y direction to arrive at a position in alignment with tray  12 . 
     Referring now to  FIG. 2 , carrier  34  is holding the first row of vials  24  in alignment with tray  12  at a height above vial conveyor  20  and also above tray  12 . Arm  30  and carrier  34  next move in the direction indicated by arrow C, i.e. in the negative X direction, to bring vials  24  into tray  12  at a height above tray  12  in order to avoid contacting the surface thereof. Pursuant to vials  24  being lifted out of vial conveyor  20 , escapement  28  opens to allow a second full row of vials  24 ′ to move along vial conveyor  20 . Alignment comb  32  is now in the retracted position where it remains until the start of the next process cycle. 
     Referring now to  FIG. 3 , arm  30  and vial carrier  34  have moved horizontally over tray  12  to the desired position for placing the carried row of vials  24  adjacent to the two previously placed rows of vials. In this position, arm  30  lowers carrier  34  vertically to place the new row of vials  24  on the surface of tray  12  without horizontal movement and without abrasion between vials  24  and tray  12 . At the same time, a further row of vials  24 ′ has moved along vial conveyor  20  to be in contact with stop  26  for being accessible for subsequent pickup by carrier  34 . Escapement  28  has returned to the blocking position for receiving and holding another row of vials. Arm  30  and carrier  34  will now move in the direction indicated by arrow D, i.e. in the positive X direction. After releasing vials  24  and moving in the positive X direction, sensors in carrier  34  confirm that no vial remains held in contact with carrier  34 . 
     Referring now to  FIG. 4 , three rows of vials  24  are situated in a nested staggered row array in tray  12  with arm  30  and carrier  34  positioned out of tray  12  slightly beyond the distal edge of vial conveyor  20 . As noted above, alternate vial array geometric arrangements are possible, e.g. straight line rows, as may be programmed by the user of the disclosed tray loader apparatus. Arm  30  and carrier  34  next move in the direction indicated by arrow E, i.e. the positive Y direction. After this positive Y movement, carrier  34  is disposed as shown in  FIG. 1  to repeat the cycle. It is noted that carrier  34  remains at the height at which the last row of vials  24  were placed onto the surface of tray  12  to engage a next row of vials  24 ′ residing in vial conveyor  20 . 
     Referring now to  FIG. 5 , a view of carrier  34  and related apparatus is illustrated in enlarged side elevation view as vials  24  are supported on vial conveyor  20  and engaged by alignment comb  32  and by carrier  34 . A similar apparatus is provided at each position of vials  24  along vial conveyor  20 . Alignment comb  32  is configured with each scalloped shape (see  FIG. 1 ) slightly larger in radius than vial  24  for holding vial  24  with no pressure to enable vial carrier  34  to lift vial  24  without rubbing. Alignment comb  32  is seen as being engaged to hold vial  24  at a nominal center distance from vials  24  adjacent thereto. In the next process step, after vial carrier  34  lifts vials  24  out of vial conveyor  20 , alignment comb  32  pivots in the direction indicated by arrow F to a retracted position awaiting a further row of vials  24  to arrive in position for being engaged. Alternate movement modes for advancing and retracting alignment comb  32 , e.g. linear motion, are similarly effective. A frame  48  is provided to mount the various components to arm  30 . Carrier  34  is configured to slidingly engage the neck portion of vial  24  slightly below cap  26 . It is noted that no portion of carrier  34  or related apparatus overrides, i.e. is not positioned directly above, the top of vial  24 , therefore minimizing the possibility of contamination. A vacuum nozzle  38  contacts the body portion at approximately the same time as carrier  34  contacts the neck portion of vial  24  and applies a vacuum to hold vial  24 . Each vacuum nozzle  38  is connected to a vacuum source (not shown) through a vacuum manifold  40 . A sensor  44 , for example a photoelectric cell, is provided at a position to detect the presence of vial  24 , with power and signal wires being bundled in a chase  46 . Alternate types of sensors are considered to be adaptable to the present invention. Vacuum manifold  40  and wires from sensors  44  are connected to a microprocessor to be described below. Whereas sensors  44  are capable of detecting the presence of a vial  24 , programming in the microprocessor can be employed to detect if a vial  24  is missing. 
     Referring now to  FIG. 6 , a block diagram is shown to portray the primary functional components of the present invention in operational connected relationship. Function control of the tray loader apparatus resides in a microprocessor  60 . A human-machine interface (HMI)  62  is provided for establishing operating parameters of a production batch and for displaying output information. HMI  62  is, according to the preferred embodiment, a screen capable of displaying an image and of receiving instructions by touch, i.e. a “touch screen.” Among optional parameters available are the number of vials per row, the number of rows per tray, and whether the rows are to be packed in straight lines or in a staggered relationship. 
     Referring further to  FIG. 6 , each sensor  44  is connected to microprocessor  60 . Microprocessor  60  initiates a detection command to sensors  44  and microprocessor  60  reacts according to the signal received to either continue or stop operations. Vacuum manifold  40  is also connected to microprocessor  60  in which a control switch activates and deactivates the vacuum at appropriate times during the operating cycle to hold or release vials. 
     Referring again to  FIG. 6 , microprocessor  60  is operatively connected to a multi-axis servo mechanical system to control the motions described above. The multi-axis servo mechanical system is characterized as Y axis servo operator  70 , X axis servo operator  72  and Z axis servo operator  74 . According to conventional design, Y axis is for horizontally forward and backward movement, X axis is for horizontally left and right movement, and Z axis is for up and down movement. 
     Referring now to  FIG. 7 , a listing of the operational steps of the invention method is provided. In steps 1, 2 and 3, an operator of the invention apparatus selects a number of vials for each row, a number of rows for a full tray, whether the rows are to be placed in the tray in a straight line packing array or staggered, and any other variables set in the program. The various parameters may alternately be incorporated in a recorded program that is called up and activated for subsequent process batches. In step 4, a vial carrier is positioned adjacent to a row of vials held in a vial conveyor. In step 5, an alignment comb is brought into contact with the vials to set vial spacing. In step 6, the carrier is moved left (negative X) to engage the vials, and a vacuum is actuated to hold the vials in position in step 7. In step 8, sensors confirm the presence of all vials, the operation being stopped in step 9 if a vial is missing. If no vial is missing, the carrier is lifted (positive Z) in step 10, and the carrier is moved back (negative Y) in step 11. The alignment comb is moved away from the vial conveyor in step 12. An escapement is opened in step 13 to pass additional vials to the position for being engaged by the carrier. The carrier is moved left (negative X) in step 14 to the position for placing the row of vials held in the carrier onto the tray. The carrier is moved down (negative Z) in step 15 to place the vials on the tray without abrasion. The vacuum is deactivated in step 16, and the carrier is moved right (positive X) in step 17. Sensors are activated in step 18 to confirm that no vials remain in the carrier, and the operation is stopped in step 19 if any vial remains. If no vial remains, the carrier moves forward (positive Y) in step 20. In step 21, the microprocessor determines whether the tray is filled by comparing the number of vials loaded with the full tray quantity established. If the tray is filled, step 22 instructs the tray conveyor to move a new tray into position for loading. In step 23, if the tray is not filled, the apparatus will repeat steps 5 through 22. 
     Whereas the description of the invention above relates to an embodiment designed for loading pharmaceutical vials onto trays, the principals disclosed herein pertain to different items sensitive to abrasion between the item being loaded and the receiving container. 
     While the description above discloses preferred embodiments of the present invention, it is contemplated that numerous variations of the invention are possible and are considered to be within the scope of the claims that follow.