Abstract:
A robotic carton erector and method of use is provided by the present invention. The robotic apparatus has a pair of movable jaws with grippers mounted thereto. The apparatus has a rail and a pair of platforms, the platforms positioned downstream of the rail. The robotic apparatus grips and opens a carton and the carton is moved into contact with the rail to close the bottom minor flaps. The carton is moved in a first direction onto a first platform to close a first bottom major flap and in a second direction onto a second platform to close a second bottom major flap. The carton bottom is then sealed.

Description:
FIELD OF THE INVENTION 
     The present invention relates to the field of corrugated carton handling equipment and method of use, and more particularly to an apparatus with a robotic arm drive component for erecting cartons from a flat condition to an open setup condition. 
     BACKGROUND OF THE INVENTION 
     Corrugated cartons are used in various manufacturing and distributing plants for packing and shipping goods. The cartons are supplied in flat condition and must be erected, i.e. reconfigured to become open three dimensional containers. The first step in the erecting process is to expand the flat carton to form a tubular three dimensional shape. The second step is to fold the bottom flaps of the carton to hold the intended contents, the first flaps folded being termed minor flaps and the later flaps folded being termed major flaps. The bottom of the erected carton is then fastened closed, e.g. by application of a tape, glue or staples. 
     Automated equipment for erecting cartons has been available for years. Examples of carton erecting equipment are shown in U.S. Pat. No. 5,156,582 for a Box Erector and U.S. Pat. No. 6,764,436 for a Method And Apparatus For Squaring Cases. Known carton erecting equipment such as these two examples are able to readily erect cartons of singular size and shape. However, the known carton erecting equipment requires time consuming adjustments to be able to handle various carton sizes or styles. In some cases, this modification may be beyond the capability of the machine. It is therefore recognized that a need exists for an automatic apparatus able to erect cartons of various sizes and styles without the need to convert the apparatus. 
     In a prior response to the need for a size adaptable automatic carton erecting apparatus, U.S. patent application Ser. No. 13/747,880 owned by the same assignee was filed on Jan. 23, 2013. The invention disclosed herein provides a further improvement of the design concepts described and claimed in this prior patent application. 
     SUMMARY OF THE INVENTION 
     The robotic carton erector of the present invention is adapted for handling a variety of carton sizes with no need for mechanical adjustments or tool changes. A controllably articulated robotic arm grasps a carton in flat condition and pulls the carton open to a rectangular shape. The robotic arm places the open carton over a curved rail and presses the carton downward to fold the bottom minor flaps into closed condition. The carton is moved laterally with the minor flaps in contact with the rail to move a first of the major flaps across a closing platform, closing the major flap and holding the closed minor flaps in position. The carton is next moved laterally in an opposite direction with the closed major flap and minor flaps held closed to then close the second major flap. Finally, the carton is moved forward across a taping head to seal the carton bottom closed. The carton is now fully erected and ready for being loaded with product. 
    
    
     
       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 perspective view of the robotic carton erector of the present invention, the carton being shown in dashed lines with score lines shown dotted. 
         FIG. 2  is a top plan view of a carton in flat condition being gripped by a pair of jaws as utilized herein. 
         FIG. 3  is a top plan view of the carton of  FIG. 2  having been opened by action of the jaws and with an outline of a larger carton shown in dash-dot lines. 
         FIG. 4  is a side elevation view of the apparatus of  FIG. 1  with a carton in opened condition with the minor flaps partially closed. 
         FIG. 5  is a front elevation view of the apparatus of  FIG. 1  with the opened carton shown with the minor flaps closed and positioned for closing a first major flap. 
         FIG. 6  is a front elevation view of the apparatus of  FIG. 1  with the opened carton shown with the minor flaps and a first major flap closed and positioned for closing the second major flap. 
         FIG. 7  is a front elevation view of the apparatus of  FIG. 1  with the opened carton with the minor and major flaps closed. 
         FIG. 8  is a side elevation view of the apparatus of  FIG. 1  with the minor and major flaps of the opened carton closed and the carton bottom being taped. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIG. 1 , an articulated robotic arm  10  is holding a rectangular carton  20  that has been opened into a rectangular tubular configuration. Carton  20  is shown in dashed lines with score lines shown in dotted lines for clarity. A pair of manipulating jaws  14   a ,  14   b  are mounted to an end of a pivoting member  12  and are seen positioned behind carton  20 . A first gripper  18   a  is mounted to first jaw  14   a  and a second gripper  18   b  is mounted to second jaw  14   b , grippers  18   a ,  18   b  preferably being vacuum controllable suction cups. Jaws  14   a ,  14   b  with grippers  18   a ,  18   b  are oriented at an angle of substantially 90° to one another to hold carton  20  open. A front minor flap  22  and a front major flap  24  are seen at the lower end of carton  20 . According to conventional terminology, the minor flaps of a carton are folded toward the center first, and the major flaps are folded toward the center of the carton thereafter to cover the minor flaps. 
     Referring further to  FIG. 1 , a rail  30  is supported on a frame (not shown) in a position below carton  20  and adjacent to robotic arm  10 . Rail  30  has a straight vertical first portion and a straight horizontal last portion that are connected by a curved central portion. Alternately, a substantially straight rail may be provided in horizontal orientation. A platform  32  is supported parallel to rail  30  on one side thereof and a second platform  36  is supported parallel to rail  30  on the opposite side thereof. Platform  32  is positioned partially adjacent to the horizontal portion of rail  30 . Platform  36  is positioned beyond the end of rail  30 . Platforms  32 ,  36  are oriented substantially coplanar. A taping device  40  is mounted to reside between the downstream ends of platforms  32  and  36 . 
     Referring further to  FIG. 1 , robotic arm  10  holds open carton  20  in angular orientation. Subsequently, carton  20  will be moved to contact rail  30  in order to close minor flap  22  and an opposite minor flap (not seen in this view). Carton  20  may be either moved along a downward angle to press both minor flaps into contact with rail  30  substantially at the same time or be moved rearwardly to contact the vertical portion of rail  30  and then downwardly to contact the horizontal portion of rail  30 . 
     Referring now to  FIG. 2 , a detail top plan view is shown of jaws  14   a ,  14   b  pressing grippers  18   a ,  18   b  into contact with flat carton  20  prior to opening. As is known, cartons are stored in flat condition to conserve space. As an initial step in the process of carton erecting, and prior to filling, the carton  20  must be expanded to a rectangular tubular shape. Grippers  18   a ,  18   b  are activated. In the preferred embodiment, grippers  18   a ,  18   b  are suction cups and activation involves applying a vacuum to grip carton  20  on each side as shown. Once grippers  18   a ,  18   b  are actively gripping the opposite exterior surfaces of carton  20 , jaws  14   a ,  14   b  are extended, i.e. spread, in the directions indicated by arrows A. 
     Referring now to  FIG. 3 , jaws  14   a ,  14   b  are oriented substantially at a 90° angle to one another. Carton  20  has been expanded from the flat condition shown in  FIG. 2  to a substantially rectangular tube. Whereas conventional carton manufacture involves gluing an overlap portion to form the corrugated sheet into a tube, it is not uncommon for some adhesive to migrate and glue the opposite interior walls of carton  20  together, causing difficulty in opening. The illustrated positioning of jaws  14   a ,  14   b  and grippers  18   a ,  18   b  has been determined to effectively open most cartons, regardless of the two opposite interior walls being glued to one another. However, occasionally the carton interior walls are glued together to a degree that effectively prevents opening without damaging the corrugated board surface. The strength applied to extend jaws  14   a ,  14   b  is calibrated to be less than that which would damage carton  20 . Any carton  20  where the adhesion between interior walls is greater than the vacuum strength is automatically rejected and an alternate carton is picked for opening. 
     Referring further to  FIG. 3 , an additional benefit of the present invention is depicted. Grippers  18   a ,  18   b  grip the carton being opened at positions adjacent to a common corner, enabling the opening of a variety of carton sizes ranging from a relatively small carton  20  to a relatively large carton  20 ′, the outline of carton  20 ′ being shown in dash-dot lines. Practical limits of carton size handled effectively by the robotic carton erector of the present invention range from 4×4 inches to 24×24 inches. A microprocessor programmed with carton data enables the robotic carton erector to accommodate different size cartons automatically. 
     Referring now to  FIG. 4 , the invention is illustrated in side elevation view with a carton  20  pressed angularly downward into rail  30  to cause bottom minor flaps  22   a ,  22   b  to be partially folded. Grippers  18   a ,  18   b  are shown holding carton  20  without showing further mechanics of the robotic arm for reasons of clarity. The robotic arm then moves carton  20  down along the central curved portion of rail  30  in the direction indicated by arrow B, causing bottom minor flaps  22   a ,  22   b  to be pressed upward by the horizontal portion of rail  30 , resulting in bottom minor flaps  22   a ,  22   b  becoming fully closed and coplanar. Carton  20  is then moved in a horizontal path of travel along the horizontal portion of rail  30  to engage bottom major flap  24  against platform  32  while rail  30  holds bottom minor flaps  22   a ,  22   b  closed. 
     Referring now to  FIG. 5 , the invention is illustrated in end elevation view with carton  20  having the bottom minor flaps coplanar, the bottom minor flaps now identified by numeral  22 , and bottom major flaps  24   a ,  24   b  extending vertically downward. Bottom major flap  24   a  resides between rail  30  and platform  32 . As shown in  FIG. 1 , platform  36  is spaced further from the end of rail  30  horizontal portion than platform  32 , therefore bottom major flap  24   b  resides behind platform  36 . With carton  20  adjacent to platform  32 , the robotic arm moves carton  20  in the direction indicated by arrow C to cause bottom major flap  24   a  to be folded into horizontal orientation to essentially lock bottom minor flaps  22  in position. The direction indicated by arrow C is substantially perpendicular to the horizontal portion of rail  30 . The top surface of platform  32  is at a height “h” below the bottom surface of rail  30  to allow bottom major flaps  24   a ,  24   b  to be folded upward. 
     Referring now to  FIG. 6 , carton  20  is shown in the condition effected affected by the action described above with bottom major flap  24   a  being in horizontal orientation and bottom major flap  24   b  in vertical orientation between rail  30  and platform  36 . Carton  20  has been moved forward to be beyond the end of rail  30  and adjacent to platform  36 . The robotic arm moves carton  20  in the direction indicated by arrow D to cause bottom major flap  24   b  to be folded up to a horizontal orientation on top of platform  36  while maintaining bottom major flap  24   a  in horizontal orientation. The direction indicated by arrow D is substantially perpendicular to the horizontal portion of rail  30  and substantially opposed to the direction indicated by arrow C (see  FIG. 5 ). 
     Referring now to  FIG. 7 , carton  20  is illustrated with bottom minor flaps  22  and bottom major flaps  24   a ,  24   b  in fully closed condition. Carton  20  is therefore ready for bottom major flaps  24   a ,  24   b  to be taped or stapled closed. 
     Referring now to  FIG. 8 , carton  20  is now supported on platform  32  and platform  36  (see  FIG. 7 ). The robotic arm, represented by grippers  18   a ,  18   b , moves carton  20  in the direction indicated by arrow E to ride over taping head  40  to seal the carton bottom. The upper flaps of carton  20  remain open. Carton  20  is moved further to a filling station or to intermediate storage. 
     A microprocessor with memory capabilities and an operator interface is built into the robotic carton erecting apparatus. Carton parameters, e.g. box dimensions, are entered into the memory with coded carton designations and motion requirements for full closure. At the start of a production run, an operator inputs a carton code via the interface with direct display on a screen. The robotic arm moves to a supply station where cartons are stacked. The robotic arm grippers descend to the carton stack from above to detect the height of the top box by means of a sensor. The sensor may be of the contact variety or electronic proximity variety. Having determined the height of the top carton and having the thickness of each carton in memory as an input dimension, the robotic arm returns for a second and subsequent cartons to the correct carton height based on calculation, not sensing. This capability allows the robotic carton erector to operate more efficiently. 
     Therefore, the operational steps for robotically erecting a carton according to the invention disclosed proceed as follows: 
     a. determining the height location of a first flat carton in a supply stack; 
     b. picking a flat carton from the supply stack with a pair of grippers; 
     c. extending the grippers to open the carton to a substantially rectangular tubular condition; 
     d. moving the open carton to press the bottom minor flaps against a rail, folding the bottom minor flaps upward; 
     e. moving the carton with bottom minor flaps folded to a first side, folding a first bottom major flap upward against the folded bottom minor flaps; 
     f. moving the carton with bottom minor flaps and the first bottom major flap folded to a second side, folding a second bottom major flap upward against the folded bottom minor flaps; and 
     g. moving the carton forward to seal the bottom major flaps in closed condition. 
     While the description above discloses a preferred embodiment of the present invention, it is contemplated that numerous variations and modifications of the invention are possible and are considered to be within the scope of the claims that follow.