Patent Publication Number: US-2005137072-A1

Title: Box-erecting machine

Description:
FIELD OF THE INVENTION  
      This invention relates to a box-erecting machine and more particularly to such a machine that operates semi-automatically.  
      The type of box or crate (hereinafter referred to as a box) which the machine of the invention is used to erect, has a rectangular configuration and is made from a diecut and creased blank of sheet material. The blank could be made of cardboard or of a polymeric material such as polyethylene. The box is further characterized in that it has an elongate upright corner post at each of its four corners, providing the essential strength of the box at its corners. Such a box is useful for stacking, one upon another. Each corner post consists of an inner part located in the inside of the box and an outer part located on its outside, the two parts being joined so as to trap and hold the walls of the box in position and generally providing rigidity to the box.  
      The invention is therefore concerned with a machine for semi-automatically erecting a rectangular box of this kind.  
     BACKGROUND TO THE INVENTION  
      The design and operation of packaging machinery are as diverse as the numerous types of packaging encountered in the packaging industry.  
      In the case of the present invention, the applicant is not aware of a box-erecting machine, semi-automatic or otherwise, which is capable of carrying out the erection of a box of the kind described above. Hitherto, the applicant has used certain jigs and tools operated by hand in order to install the four corner posts in the corners of a box of the type in question. This has proved to be laborious and time consuming and, indeed, the applicant believes that such manual erection of boxes will not meet the requirements of modern pack-houses where agricultural produce, for example, is packed in large quantities in relatively short periods of time.  
     OBJECT OF THE INVENTION  
      It is accordingly an object of the invention to provide a semi-automatic box-erecting machine which is capable of efficiently erecting boxes of the type described above at a rate in the order of 360 boxes per hour or more.  
     SUMMARY OF THE INVENTION  
      A box-erecting machine according to the invention comprises a support structure and a rotatable head mounted on the support structure for rotation about an axis, the rotatable head carrying a plurality of four-cornered mandrels, means for displacing each mandrel away from and towards the rotatable head, and means for rotating the rotatable head in discrete steps so as to locate each mandrel at consecutive erecting stations of the machine and thereby to permit progressive erection of a rectangular box through the erecting stations from a blank of sheet-like material with corner posts located and connected in each of the four corners of the box.  
      Each mandrel may comprise a plurality of displaceable parts defining the corners of the mandrel, each mandrel being expandable to an expanded configuration in which the corners are located in a pre-determined expanded formation, and contractable to a contracted configuration in which the corners are located in a pre-determined contracted formation.  
      More particularly, the plurality of erecting stations of the machine may comprise; 
          a first erecting station at which an inner part of a corner post is locatable on each of the four corners of a mandrel;     a second erecting station including a platform surrounding a blank-folding cavity, the mandrel being displaceable into the cavity to fold a blank located on the platform into a rectangular box consisting of a base, two opposed side walls and two opposed end walls, the mandrel being expandable within the cavity to its expanded configuration to locate the inner parts of the corner posts in the four inner corners of the rectangular box, the mandrel, with the box, being displaceable from the box-folding cavity;     a third erecting station including four post-holding devices, an outer part of a corner post being locatable in each post-holding device, the mandrel, carrying the box, being displaceable into alignment with the post-holding devices, the post-holding devices being simultaneously displaceable towards the mandrel to connect each outer part of each post with its respective inner part located in the box and thereby to trap and hold the walls of the box by means of the corner posts, the post-holding devices being retractable and the mandrel being displaceable from its position adjacent the post-holding devices; and     a fourth erecting station including a receiving platform, the mandrel being displaceable to locate the box on the receiving platform, the mandrel being contractable to its contracted configuration, thereby releasing it from the box, the mandrel being displaceable from the receiving platform, and box-ejecting means being provided for ejecting the box from the receiving platform onto a conveyor or the like.        

      The rotating head preferably comprises four equally spaced radial arms each carrying a mandrel in dependent fashion. Each mandrel may be mounted on its associated arm by means of a pair of vertical shafts for vertical displacement relative to the support structure of the machine and may comprise a hub carried by the vertical shafts and a pair of opposed cheek plates defining the four corners of the mandrel, the cheek plates being mounted for horizontal displacement away from and towards the central part to permit expansion and contraction of the mandrel respectively.  
      The means for displacing each mandrel may comprise a pneumatic piston and cylinder assembly mounted between each pair of shafts.  
      The means for rotating the rotating head may comprise electric drive means arranged to rotate the rotatable head through consecutive 90° steps in an indexing fashion to locate each mandrel consecutively at each erecting station of the machine.  
      The invention also contemplates a method of erecting a box comprising, 
          providing a box-erecting machine having a support structure and a rotatable head mounted on the support structure for rotation about an axis, the rotatable head carrying a plurality of four-cornered mandrels, means for displacing each mandrel away from and towards the rotatable head, and means for rotating the rotatable head,     rotating the head in discrete steps so as to locate each mandrel at consecutive erecting stations of the machine, and     progressively erecting the box through the erecting stations from a blank of sheet-like material to provide corner posts located and connected in each of the four corners of the box.       

    
    
      A preferred embodiment of the invention will now be described by way of example only, with reference to the accompanying drawings in which;  
       FIGS. 1 and 2  are perspective views from opposite sides respectively of a box-erecting machine showing its main components;  
       FIGS. 3-6  are side views of the machine showing each one of four erecting stations of the machine;  
       FIGS. 7 . 1 - 7 . 2  illustrate the operations at a first erecting station of the machine;  
       FIGS. 8 . 1 - 8 . 5  illustrate the operations at a second erecting station of the machine;  
       FIGS. 9 . 1 - 9 . 8  illustrate the operations at a third erection station of the machine;  
       FIGS. 10 . 1 - 10 . 5  illustrate the operations at a fourth erecting station of the machine;  
       FIG. 11  is a perspective view of the inner and outer parts of an upright corner post used at each of the four corners of a box erected with the use of the machine of the invention;  
       FIG. 12 . 1  is a similar view of the two parts of the corner post connected together at the corner of such a box;  
       FIG. 12 . 2  is an enlarged cross-section taken on lines A-A of  FIG. 12 . 1 ; and  
       FIG. 13  is a perspective view of a box erected using the machine of invention. 
    
    
      Referring firstly to  FIGS. 11-13  of the accompanying drawings, there is shown a rectangular box  80  and its constituent parts. Typically, the box has a base  81 , opposed side walls  82 , opposed end walls  83  and a pair of openable lids  84 , all made from a single blank of sheet material such as polyethylene. The box is held together by four upright corner posts  85 , each of which comprises an inner part  86  and an outer part  87 . The inner and outer parts  86 ,  87  are held together by a snap fit in which lugs  88  on the inner part are snap fitted into apertures  89  in the outer part  87 . When the inner and outer parts  86 ,  87  are thus engaged, they trap and hold the ends of the side walls and end walls  82 ,  83  respectively at each corner of the box  80 . As will be most evident from  FIG. 12 . 2 , the lugs  88  of the inner part  86  of a post  85  are accommodated in apertures  90  in the side walls and end walls  82 ,  83  of the box, which apertures are provided along the height of the walls at positions corresponding to the lugs  88  and apertures  89  of the posts  85 .  
      It is for the step-wise erection of a box  80  described above that the box-erecting machine of the present invention is intended.  
      One embodiment of such a machine, designated by numeral  50  and showing its principal components, is illustrated in  FIGS. 1-6 .  
      In this embodiment of the invention, the box-erecting machine  50  comprises a support structure  51  on which is mounted a pillar  52  carrying a rotating head  53  rotatable about a vertical axis  54 . The rotating head comprises four equally spaced radial arms  55  each carrying a mandrel  56  in dependent fashion at its free end. Each mandrel  56  is mounted on its associated arm  55  by means of a pair of vertical shafts  58  for vertical displacement relative to the support structure  51 . Means are provided for displacing each mandrel by lowering and raising each mandrel, in the form of a pneumatic piston and cylinder assembly  59  located between each pair of vertical shafts  58 .  
      Each mandrel comprises a hub  60  carried by the vertical shafts  58  and a pair of opposed cheek plates  61  mounted on the hub  60  for horizontal displacement away from and towards the hub. Each cheek plate  61  defines a pair of corners  61   a  of the mandrel, with the two cheek plates  61  defining four corners of the mandrel ( FIGS. 1, 7 . 1 ).  
      Displacement of the cheek plates  61  away from a hub  60  results in a mandrel  56  being expanded to an expanded configuration in which the corners  61   a  are located in a pre-determined expanded formation, as may be seen, for example in  FIGS. 1, 2  and  5 ,  6 . Such displacement may be effected by means of hydraulically or pneumatically actuated rods  56   a . Displacement of the cheek plates towards the hub  60  results in a mandrel being contracted to a contracted configuration in which the corners  61   a  are located in a pre-determined contracted formation, as may be seen, for example, in  FIGS. 1, 2  and  3 ,  4 . Such displacement is, in this embodiment of the invention, effected by mandrel contracting means  42  as hereinafter described.  
      Means are provided for rotating the rotating head  53  about the axis  54  in discrete consecutive steps of 90° each, in an indexing fashion. Thus, each mandrel  56  is consecutively located at one of four box-erecting stations designated generally by numerals  10 ,  20 ,  30  and  40 , to which reference will be made more fully hereunder.  
      In this embodiment of the invention, the means for rotating the rotating head  53  comprise a chain  70  riding on a cog  71  mounted on the rotating head at its underside. The chain  70  is driven by a gear  72  which itself is driven by an electrical motor  73  ( FIG. 3 ).  
      The electric motor  73  is controlled by a sensor  74  mounted on an arm  75  located beneath the rotating head  53  ( FIG. 4 ). The sensor  74  functions in conjunction with sensors (not shown) located on the radial arms  53  to ensure step-wise rotation of the rotating head  53  as described above.  
      The operation of the box-erecting machine  50  through its four box-erecting stations  10 ,  20 ,  30  and  40  will now be described with reference to  FIGS. 7-10 .  
      Box-Erecting Station  10   
      The first box-erecting station is station  10  shown in  FIGS. 7 . 1 - 7 . 2 . At this station the inner part  86  of a corner post  85  is manually located on each of four corners  61   a  of a mandrel  56 . For this purpose the corners of the mandrel  56  are suitably shaped to receive the inner parts  86 . In  FIG. 7 . 1  the inner parts  86  are shown separate from the mandrel and in  FIG. 7 . 2 , they are shown located on the four corners of the mandrel.  
      Box-Erecting Station  20   
      The second box-erecting station is shown in  FIGS. 8 . 1 - 8 . 5 . At this box-erecting station a platform  21  is provided surrounding a blank-folding cavity  22 . In operation, upon rotation of the rotating head  53 , the mandrel  56  from box-erecting station  10  comes to rest above the blank-folding cavity  22  ( FIG. 8 . 1 ). A diecut and creased blank  23  from which the box  50  is to be formed is located on the platform  21  against stop members  24  ( FIG. 8 . 2 ). The mandrel  56  is thereupon displaced downwardly into the blank-folding cavity  22 , thereby folding the blank  23  into opposed sidewalls  82  and end walls  83  rising from the base  81  of the box  80  ( FIGS. 8 . 3 ,  12 . 1 ).  
      Next, the mandrel whilst located in the blank-folding cavity is expanded by outward displacement of its cheek plates  61  to its expanded configuration ( FIG. 8 . 4 ) which serves firmly to locate the inner parts  86  of the corner posts  85  in the four corners of the box  80 .  
      At the same time that the mandrel  56  is displaced downwardly into the blank-folding cavity, pneumatic suction is applied through ports  26  in the cheek plates  61  of the mandrel  56  to facilitate the retention of the now folded blank on the mandrel. The last step at station  20  is withdrawal of the mandrel by means of the piston and cylinder assembly  59  to the former position of the mandrel above the blank-folding cavity  22  ( FIG. 8 . 5 ). Rotatable rollers  25  are provided in each corner of the blank-folding cavity  22  ( FIG. 8 . 5 ). The rollers  25  are located at right angles to one another in each corner of the blank-folding cavity to facilitate sliding displacement of the box  80  along each corner when the mandrel is withdrawn form the blank-folding cavity.  
      Box-Erecting Station  30   
      The third box-erecting station is shown in  FIGS. 9 . 1 - 9 . 8 . At this box-erecting station four post-holding devices  31  are provided on the support structure  51 , each capable of forward and rearward displacement by means of a pneumatic piston and cylinder assembly  32  ( FIG. 9 . 1 ). Additionally, a pair of flap-folding devices  33  is provided on a peripheral shelf  34  located above the post-holding devices  31 . Each flap-folding device  33  is capable of forward and rearward displacement by means of a pneumatic piston and cylinder assembly  35  ( FIG. 9 . 1 ).  
      An outer part  87  of a corner post  85  is manually placed in each of the post-holding devices  31 . In  FIG. 9 . 1  the outer parts  87  are shown at the post-holding devices but spaced therefrom and in  FIG. 9 . 2  they are shown as placed in position in the post-holding devices.  
      In operation, upon rotation of the rotating head  33 , the mandrel  56  from the box-erecting station  20  comes to rest at box-erecting station  30  ( FIG. 9 . 3 ). The mandrel is then displaced downwardly into alignment with the post-holding devices  31  ( FIG. 9 . 4 ), whereupon the flap-folding devices  33  are operated to fold each of the short flaps  83   a  of the box  80  inwardly over the mandrel  56  ( FIG. 9 . 5 ). The post-holding devices  31  are next activated to connect the outer parts  87  of the upright posts  85  to their respective inner parts  86  to complete the construction of the box  80  ( FIG. 9 . 6 ). The flap-folding devices  33  and post-holding devices  31  are thereupon retracted ( FIG. 9 . 7 ) and the mandrel is raised to its former position ( FIG. 9 . 8 ).  
      Box-Erecting Station  40   
      The fourth and final box-erecting station  40  is shown in  FIGS. 10 . 1 - 10 . 5 . At this station a receiving platform  41  is provided between a pair of mandrel collapsing means  42 . Each mandrel collapsing means  42  comprises a rod  43  operated by a pneumatic piston and cylinder assembly  44  mounted on a housing  45 . Additionally, box-ejecting means  46  are provided comprising an ejecting plate  47  carried on shafts  48  operated by a pneumatic piston and cylinder assembly  49 .  
      In operation, upon rotation of the rotating head  53 , the mandrel  56  with its now erected box  80  comes to rest above the receiving platform  41  ( FIG. 10 . 1 ). The mandrel is lowered on to the receiving platform  41  and the mandrel contracting means  42  are activated which causes each of the rods  43  to advance through an aperture in the end panels  83  of the box  80  and to collapse the cheek plates of the mandrel into its contracted configuration ( FIG. 10 . 3 ). The rods  43  are withdrawn and the mandrel is raised out of the box  80  to its former position above the receiving platform  41  ( FIG. 10 . 4 ). The box-ejecting means  46  are activated causing the ejecting plate  47  to eject the box  80  from the receiving platform  41  ( FIG. 10 . 5 ) on to a conveyor or the like (not shown).  
      In its operation, manual participation of operators is required for operating the box-erecting-machine  50  described above. Typically, two operators could be positioned at each of the first and third stations  10 ,  30  and one operator at the second station  20 . Safeguards can be included in the machine to prevent accidental or untimely rotation of the rotating head  53 . For example, if there are two operators at station  30  inserting outer parts of the corner posts  85 , dual switches (not shown) can be provided requiring that both operators press a switch before the rotating head is rotated. So too, a stop switch  76  is provided on each radial arm  55  which can be pressed by any operator ay any time to stop all operations of the machine.  
      Other embodiments of the invention may be made differing in matters of detail and without departing from the scope of the invention as described in the appended claims.