Abstract:
A packing method and system are disclosed which system includes a first platform having a product support surface for supporting a product and a second platform for supporting a box into which the product is to be packed. After a box is received on and secured to the second platform, the second platform is rotated so that the open top of the box faces the first platform and moved toward the first platform until the box substantially surrounds the product on the product support surface. The first and second platforms are then rotated simultaneously so that the product is transferred from the product support to the box, and the full box is discharged to a discharge conveyor.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS AND CLAIM TO PRIORITY 
     The present application claims the benefit of U.S. provisional patent application serial No. 60/290,342, filed May 14, 2001, the disclosure of which is incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention is directed to a method and apparatus for packaging a product, and, more specifically, toward a method and apparatus for transferring a plurality of stacks of discrete objects supported by a platform from the platform to a box while maintaining the integrity and arrangement of the stacks. 
     BACKGROUND OF THE INVENTION 
     Various packing or packaging machines are known for placing a product into a box, carton, or other container. However, special problems are encountered when the product to be packaged comprises stacks of discrete objects. These stacks, for example, may have previously been formed by a stacking machine and set on a support surface for further processing. Such stacks can be lifted manually and placed into a box, but if multiple stacks have to be placed in the same box, it can be difficult to maintain the integrity of the stacks as they are moved; this leads to the occasional need for a manual restacking step. Furthermore, it is difficult to lift multiple adjacent stacks of objects at the same time by hand, and therefore a person would normally be limited to lifting the stacks one at a time when placing them in a box. However, if the stacks are to be packed tightly in the box, that is, if they are to be packed with a minimal amount of space between the stacks themselves and between the stacks and the inner walls of the box, it may be difficult to manually position the stacks that are adjacent a sidewall, and especially difficult to place the last stack into a box, which stack will be bounded on four sides by box sidewalls or other stacks of products. 
     Stacks of products such as those discussed above can be moved by gripping the top and bottom of the stack and applying pressure to hold the stack together while it is moved. An apparatus for gripping and moving stacks in this manner is disclosed in a co-pending application entitled “Stack Transfer Device” filed concurrently herewith and assigned to the assignee of this application, the disclosure of which is hereby incorporated by reference. However, gripping a stack from the top and bottom makes it difficult to insert the stack into a previously formed box having an open top. To package a stack that is gripped in this manner, either a box must be formed around the stacks of objects while they are being gripped, or the objects must be deposited on a surface and moved again from the surface to a box. 
     When using a stack transfer device, such as the one disclosed in the above application, the stacks are often placed on a device called a matrix former before they are packaged. A matrix former comprises a horizontal platform and two or three upstanding, movable sidewalls forming a structure that resembles a cube with an open top and no front wall. The purpose of the matrix former is to consolidate several stacks by sliding them toward one another and removing the spaces therebetween, to make them easier to fit into a box. The upstanding walls of the matrix former, however, make it even more difficult to transfer the stacks from the matrix former to a preformed box or case. It would therefore be desirable to provide a method and apparatus for automatically, simultaneously, transferring a plurality of stacks of discrete objects from a support platform, such as a matrix former, to a box in a manner that preserves the integrity and arrangement of the stacks. 
     SUMMARY OF THE INVENTION 
     These problems and others are addressed by the present invention which comprises a method and apparatus for transferring objects, and especially multiple stacks of discrete objects, from a support surface to an open-topped box. While the present invention could be used in a number of environments, it finds particular use in transferring stacks of frozen hamburger patties from a support surface having upstanding walls to an open-topped cardboard box and will be described in terms of such as system, it being understood that the invention is by no means limited to use in such environments. 
     The preferred embodiment of the invention comprises a first generally horizontal platform, which forms a part of a matrix former, on which a plurality of stacks of discrete objects are to placed, and a second platform for supporting a box into which the stacks are to be packed. The second platform is movable vertically and can also be pivoted about an axis parallel to its box-contacting surface. The second platform includes at least one gripper for holding the bottom of the box securely against the box-contacting surface and, preferably, also includes a plurality of fingers for engaging the top edges of the box to control the movement of the box and to hold down flaps extending from the top edge of the box. The box-contacting surface of the second platform also preferably includes a plurality of rollers that allow an empty box to roll on and off the platform when the platform is inclined. 
     In operation, the second platform is aligned with a conveyor that feeds empty boxes one at a time. A box rolls onto the second platform and is gripped by at least one gripper on the second platform to hold it in place, with its bottom on rollers and its open top facing away from the rollers. The second platform is then pivoted 180 degrees to an inverted position, with the open box top positioned over and facing down towards the first platform above the stacks of objects on the first platform. The second platform is next lowered over the stacked objects, until the first platform is about even with or slightly inside the top opening of the box so that the stacks of objects are disposed completely within the box. The orientation of the stacked objects is maintained by the walls of the box and the platform. The first and second platforms are pivoted together, until the top opening of the box is again facing upwardly and the objects are supported on the closed bottom of the box rather than by the first platform. The second platform and box are moved away from the first support, so the first support may return to its original orientation. The second support is then moved to a discharge location where it tilts to slide the fully loaded box onto a conveyor for further processing, and finally the second support returns to its original position to receive another empty box from the feeding conveyor to start the process again. 
     It is therefore a principal object of the present invention to provide an apparatus for packing a plurality of stacks of discrete objects in a container. 
     It is another object of the invention to provide an apparatus for transferring a plurality of stacks of discrete objects from a platform to a box while maintaining the integrity and mutual relationship of the stacks. 
     It is a further object of the invention to provide a method for packing a plurality of stacks of discrete objects in a box. 
     It is still another object of the invention to provide a method of packing stacks of discrete objects supported by a platform having at least one upstanding sidewall taller than the stacks of objects. 
     It is yet another object of the invention to provide an apparatus for simultaneously boxing a matrix of discrete objects. 
     In furtherance of these objects, a packing apparatus is provided that includes a first platform having a product contact surface. The first platform is pivotable about an axis parallel to and spaced from the product contact surface between a first position, wherein the product contact surface faces in a first direction, and a second position, wherein the product contact surface faces in a second direction. The apparatus also includes a second platform comprising a box support having a box contact side and a box holder for holding a box on the box support. The second platform is movable between a first position and a second position, and the box support is pivotable between a first angular orientation and a second angular orientation. 
     Another aspect of the invention comprises a method of packing a product that involves providing a first platform having a product support surface facing in a first direction and placing a product to be packaged on the product support surface. A second platform including a box support having a box contact surface is aligned with a first conveyor and receives a box having a closed bottom and an open top. The box is secured to the box support with the closed bottom in contact with the box contact surface. The box support is pivoted so that the box contact surface faces the first platform product support surface and the box open top faces the product. The second platform is moved towards the first platform until the product passes through the box top opening, and the first platform and the box support platform are pivoted until the box open top faces in the first direction. The second platform is moved away from the first platform, and the first platform is pivoted until the product support surface faces in the first direction. The second platform is aligned with a second conveyor, and the box is released onto the second conveyor. 
     Another aspect of the invention comprises a packing apparatus that includes a first platform having a product contact surface that is pivotable, via an actuator, about an axis parallel to and spaced from the product contact surface between a first position, wherein the product contact surface faces in a first direction, and a second position, wherein the product contact surface faces in a second direction. The apparatus also includes a second platform that includes a box support having a first wall and a box contact side and a positioning device for positioning and holding a box on the box support. The positioning device includes a second, movable, wall and an actuator for moving the movable wall with respect to the first wall. At least one gripper is also provided for gripping an edge of a box having a closed bottom and open top on the box support. The second platform is movable between a first position and a second position, and the box support is pivotable between a first angular orientation and a second angular orientation with respect to said first platform. The apparatus also includes at least one guide track for guiding the movement of the second platform between the first position and the second position, a drive belt extending between a first wheel and a second wheel, and a drive operably coupled to the drive belt. The second platform is coupled to the drive belt. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other objects and other objects and advantages of the invention will be better understood after a reading of the following detailed description of the invention together with the following drawings. 
     FIG. 1 is a perspective view of the packing system of the present invention which system includes a feeding conveyor, a discharge conveyor, a lift apparatus and a matrix former. 
     FIG. 2 is an assembly diagram of the lift apparatus of the packing system shown in FIG.  1 . 
     FIG. 3 is an exploded perspective view of matrix former of FIG.  1 . 
     FIG. 4 is a rear elevational view of the motor of the matrix former of FIG.  1 . 
     FIG. 5 is a fragmentary perspective view of the box holding portion of the lift apparatus in an inverted position. 
     FIG. 6 is an elevational view of the matrix former of FIG.  1 . 
     FIG. 7 is a side elevational view of the packing system of FIG. 1 in a first configuration with the lift positioned to receive an empty box from the feeding conveyor. 
     FIG. 8 is a side elevational view of the packing system of FIG. 1 in a second configuration with an empty box gripped on a platform of the lift apparatus. 
     FIG. 9 is a side elevational view of the packing system of FIG. 1 in a third configuration with the platform and box positioned over the matrix former. 
     FIG. 10 is a side elevational view of the packing system of FIG. 1 in a fourth configuration with the platform held near the matrix former so that the matrix former is substantially covered by the box. 
     FIG. 11 is a side elevational view of the packing system of FIG. 1 in a fifth configuration with the platform and matrix former rotated 180 degrees from the position shown in FIG.  8 . 
     FIG. 12 is a side elevational view of the packing system of FIG. 1 in a sixth configuration with the platform moved away from the matrix former. 
     FIG. 13 is a side elevational view of the packing system of FIG. 1 in a seventh configuration showing the matrix former pivoted 180 degrees from the position shown in FIG.  10 . 
     FIG. 14 is a side elevational view of the packing system of FIG. 1 in an eighth configuration with the platform and box raised to the level of the discharge conveyor. 
     FIG. 15 is a side elevational view of the packing system of FIG. 1 in a ninth configuration showing a full box that has been released from the platform to the discharge conveyor and a new empty box in position on the feeding conveyor. 
     FIG. 16 is a side elevational view, partly in section, of the lift apparatus and the matrix former in a position similar to that shown in FIG.  8 . 
     FIG. 17 is a side elevational view, partly in section, of the lift apparatus and the matrix former in a position similar to that shown in FIG.  9 . 
     FIG. 18 is a side elevational view, partly in section, of the lift apparatus and the matrix former in a position similar to that shown in FIG.  10 . 
     FIG. 19 is a side elevational view, partly in section, of the lift apparatus and the matrix former in a position similar to that shown in FIG.  11 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only, and not for the purpose of limiting same, FIG. 1 shows a packing apparatus designated generally by the numeral  110  which includes an empty-box feeding conveyor  12 , a packed-box discharge conveyor  14 , a lift mechanism  16 , and a matrix former  18 . 
     Lift mechanism  16 , as best shown in FIG. 2, includes a reversible motor  20  for turning a drive shaft  22  which is supported on one end by motor  20  and on the other by a bearing  24  mounted on a support (not shown). First and second flanged wheels  26  are mounted on shaft  22  for rotation therewith, and a second shaft  28  is rotatably supported by first and second bearing plates  30  mounted to supports (not shown) parallel to the drive shaft  22 . First and second flanged wheels  32  are mounted on second shaft  28  and aligned with the flanged wheels  26  on the drive shaft  22 . First and second belts  34  extend between aligned pairs of flanged wheels  26  and  32  on the shafts  22  and  28  such that shafts  22  and  28  are rotated simultaneously when motor  20  turns drive shaft  22 . Parallel guide tracks  36  are mounted adjacent the belts  34 , each track  36  defining a channel facing toward the channel of the other track  36 . 
     Lift platform  40  includes a first sidewall  42 , a second sidewall  43 , a top support  44 , and a bottom support  46  supported for rolling movement along the guide tracks  36  by wheels  48 , as best shown in FIG. 7, and is clamped to belts  34  by clamps  50 . Thus, motor  20  moves lift platform  40  between raised and lowered positions on guide tracks  36  by rotating shaft  22 . Motor controller  51  controls the operation of motor  20 , and thus the position of lift platform  40  with respect to the guide tracks  36  and the matrix former  18 . 
     Lift platform  40 , as best shown in FIG. 2, further includes a pivoting platform  52  mounted on lift platform  40  for pivoting movement with respect to platform  40 . Platform  52  includes a base frame  54 , including a projecting arm  56  and a sidewall  58 . A first axle  60  extends from first sidewall  42  and connects to sidewall  58 , while a second axle  62  extends from second sidewall  43  and connects to projecting arm  56 . The axles  60  and  62  are coaxial. Under the influence of appropriate actuators, pivoting platform  52  may be pivoted between first and second positions with respect to lift platform  40 . 
     Pivot platform  52  further includes a guide track  64 , as best shown in FIG. 5, connected between sidewall  58  and sidewall  43 , a first fixed wall  65  adjacent track  64  and a second wall  66  slidingly connected to track  64 . An actuator  68 , shown in FIG. 5, is mounted adjacent track  64 , for moving sliding wall  66  toward and away from fixed wall  65  to grip a box placed therebetween. A roller support  70 , comprising a plurality of free-spinning rollers, is mounted on base frame  54  between sidewalls  43  and  58 . Four posts  72  extend from walls  65  and  66  which posts are mutually parallel and arranged generally in a square. The top of each post  72  includes a finger  74  pivotally attached thereto, and an actuator  76  connects each finger  74  to the top of sidewall  65  or sliding wall  66 , so that the fingers  74  can be pivoted between first and second positions with respect to the sliding walls by the actuators  76  and function as grippers for gripping the top edge of a box. 
     A crank arm  80 , as best shown in FIG. 1, is attached to the end of axle  60 , and a first cylinder and piston assembly  82  extends between crank arm  80  and sidewall  42  of lift platform  40 . A second cylinder and piston assembly  84  extends between pivot platform  52  and sidewall  42 . Operation of the first and second cylinder and piston assemblies  82  and  84  moves pivot platform  52  between first and second positions. 
     Referring now to FIGS. 3,  4  and  6 , matrix former  18  can be seen to comprise a reversible motor  90  for rotating a drive shaft  92  approximately 180 degrees between first and second positions. Plate  94 , having first and second ends  96 , is supported on shaft  92 , and first and second arms  98  are attached to the ends  96  of plate  94 . Arms  98  are connected to a shaft  100  by a triangular plate member  102 . One end of shaft  100  is connected to a first vertex of plate member  102 , while arms  98  are connected to the other two vertices of the triangular plate member  102 . Shaft  100  is securely supported by two bearing plates  104  fixedly mounted to a support structure  106 , as best shown in FIG.  1 . An L-shaped support  108  depends from shaft  100  and includes a projection  110  for supporting an actuating assembly  112 . Actuating assembly  112  comprises side plates  114  connected by telescoping cylinders  116  and an actuator  118 . The matrix former  18 , as best shown in FIG. 3, further includes a patty-receiving platform  120  having three slots  122  therein, a first sidewall  124  connected to one of the side plate  114 , and a second sidewall  126  connected to the other of the side plates  114 . (The slots  122  are narrower than the width of the patties to be placed thereover.) The sidewalls  124  and  126  are movable toward and away from each other by operation of the actuating assembly  112  which is attached to the two side plates  114 . FIG. 6 illustrates three stacks  128  of hamburger patties between the sidewalls  124 ,  126  of the matrix former  18  in a closely spaced relationship. 
     In operation, a first set of three stacks of hamburger patties is placed onto receiving platform  120 , one stack over each of slots  122 , by a stack placing device (not shown). A second set of three stacks is then placed on receiving platform  120  next to the first set of stacks by the stack placing device. The stacks are formed with a spacing between them, and are thus transferred to the receiving platform  120  with a spacing. To remove or substantially decrease this spacing, controller  51  operates actuator  118  to move side plates  114 , and thus first and second sidewalls  124  and  126  which are connected to side plates  114 , toward each other to slide the patties toward one another and form a tighter matrix of patties. 
     FIGS. 7 through 15 illustrate the interaction of the lift mechanism  16  and the matrix former  18  during one patty boxing operation. In FIG. 7, system  10  can be seen with an empty box  130 , having an opening  132 , that has been released to slide down box feed roller conveyor  12  toward and onto roller support  70  of lift platform  40 . At this stage, matrix former  18  already holds six stacks (two rows of three stacks each) of hamburger patties. Once box  130  is received on roller platform  70 , sliding side walls  66  are moved toward each other and toward box  130  by actuator  68 , until they engage the sidewalls of the box and hold box  130  securely on platform  70 . Actuators  76  pivot fingers  74  and move them into the opening  132  of box  130 , where they further secure the box to the roller platform  70  and help hold down any flaps that the box might have. Platform  70  is then pivoted to the position shown in FIG. 8, with its surface generally normal to guide tracks  36 . First cylinder and piston assembly  82 , with a first end connected to first sidewall  42 , presses against crank arm  80  on first axle  60 , which causes pivoting platform  52  to pivot about the axes of first axle  60  and second axle  62  from the position shown in FIG. 8 to the position shown in FIG. 9 so that roller platform  70  is positioned over matrix former  18  and with the opening  132  of box  130  facing the stacks of patties on the matrix former. Sliding sidewalls  66  and fingers  74 , held in place by actuators  76 , keep box  130  secured with its bottom wall against roller platform  70 . 
     Controller  51  next causes motor  20  to rotate shaft  22 , in order to move belts  34  and thus platform  70  toward matrix former  18  until the sidewalls  124 ,  126  of the matrix former  18  and the patties on the matrix former surface  120  are inside box  130 , as best shown in FIG.  10 . In this position, shaft  100  of the matrix former is coaxially aligned with axles  60  and  62  of the lift platform. 
     Next, matrix former motor  90  actuates to rotate plate  94  and move one of the arms  98  toward shaft  100  and the other of arms  98  away from the shaft  100 , thus rotating triangular plate  102  and shaft  100  connected thereto. This causes the receiving platform  120  to pivot about the axis of shaft  100 . Simultaneously, first cylinder and piston assembly  82  and second cylinder and piston assembly  84  contract to pivot roller support platform  70  about axles  60  and  62 , so that the box  130  on the roller support platform  70  and the patty support platform  120  of the matrix former remain essentially parallel as they rotate through 180 degrees to the position shown in FIG.  11 . The patties, which had been supported by receiving platform  120  and covered by box  130 , are in this new orientation supported by box  130  with the receiving platform  120  positioned thereover. 
     Motor  20  next rotates shaft  22  to move roller support platform  70  and box  130  thereon away from patty support platform  120  and away from shaft  22  until the patty support platform  120  is clear of the box  130 , as best shown in FIG.  12 . Motor  90  rotates shaft  100  to return the patty support platform  120  to its starting orientation as best shown in FIG.  13 . Roller support platform  70  is next raised to the position shown in FIG. 14, generally parallel to the surface of discharge conveyor  14 . Actuators  76  pivot fingers  74  out of top opening  132  of the box  130  and sliding sidewall  66  moves away from box  130 . The box  130  may then slide under the force of gravity off roller platform  70  and onto the adjacent discharge conveyor  14  as best shown in FIG.  15 . The lift platform  40  is then raised back toward the feed conveyor  12  to receive another box and start the cycle again. 
     FIGS. 16-19 show in more detail the transfer of the stacks of patties  128  from the matrix former  18  to the box  130 . FIG. 16 is a sectional view showing the inside of the box  130  and the matrix former  18  when the box  130  is held over the matrix former  18  as shown in FIG.  9 . As can be seen in FIG. 17, the support platform  120  of the matrix former fits within the inside of box  130 , with a small amount of clearance, and at about the level of opening  132 . FIG. 18 shows the inside of box  130  when the matrix former  18  and lift platform  40  are positioned as in FIG. 11, so that the stacks  128  of patties are now resting on the bottom of box  130 . FIG. 19 corresponds to the position of the matrix former  18  and lift platform  40  shown in FIG.  12 . 
     The present invention has been described herein in terms of a preferred embodiment. However, numerous changes and additions to this embodiment will become apparent to those skilled in the relevant arts upon a reading and understanding of the foregoing description. For example, while the matrix former of the present invention has been described as accommodating two rows of three stacks each, it can readily be adapted, by the use of larger or smaller components, have more or fewer slots in the bottom wall, to accommodate rows having a greater or lesser number of stacks and to accommodate a greater or lesser number of rows as well. It is intended that all such changes and additions be included within this invention to the extent that they are covered by scope of the several claims appended hereto.