Patent Publication Number: US-7721509-B2

Title: Device for packing items in a box, and a method for the same

Description:
BACKGROUND OF THE INVENTION 
   The invention relates to a device for packing items in a box, which device is provided with a conveyor for supplying items in a conveyance direction, a pushing device comprising a pressure plate, which pressure plate is movable in a horizontal pushing direction extending transversely to the conveyance direction, for moving at least one item onto a flap that is movable from a closed position to an open position and vice versa, a box being positionable below the flap, which device is additionally provided with two guide plates situated on either side of the flap, which guide plates extend transversely to the pressure plate. 
   The invention also relates to a method for packing items in a box by means of such a device. 
   Items are, for example, bags, small boxes, bottles, jars, packets etc. 
   In such a device and method disclosed by American patent U.S. Pat. No. 4,864,801, items such as bags are conveyed in a virtually lying position by means of a conveyor until the bags are pressed against a stop plate positioned at an angle and are set substantially upright. A number of bags are then positioned simultaneously by means of a pressure plate on a flap in a pushing direction extending transversely to the conveyance direction. Guide plates are disposed on either side of the flap, a guide plate being situated at the same angle as the stop plate. After that, the guide plate positioned at an angle is tilted to a vertically extending position. The flap is then opened, and the bags standing on the flap fall into a box standing ready below the flap. 
   A disadvantage of a guide plate positioned at an angle is that the bags standing on the flap shift relatively easily in relation to each other, for example if a following row of bags is pressed against a row of bags already standing on the flap. There is then a risk that the rows will be disturbed and will not be positioned in the correct configuration on the flap. This upsets the placing of the bags in the box. 
   SUMMARY OF THE INVENTION 
   The object of the invention is to provide a device by means of which items can be placed accurately in a box. 
   This object is achieved with the device according to the invention in that the device is provided with a retaining plate extending parallel to the pressure plate and movable in the pushing direction, which device is further provided with a stop situated between the retaining plate and the pushing device, which stop is situated at a distance above the flap that is less than the height of the item, the item and/or the stop being deformable during the movement of the item on the flap. 
   By providing the retaining plate which is movable in the pushing direction, it is ensured that items cannot accidentally shift in the pushing direction. The retaining plate is preferably moved simultaneously with the items in the pushing direction, the items being situated firmly between the retaining plate and the pressure plate. In this way it is ensured that the items positioned on the flap are in a compact orientation resting against each other. 
   The stop retains items standing on the flap that have a tendency to fall over in the direction of the pressure plate. When items are being moved by means of the pressure plate from the conveyance direction, the items are pushed past the stop and are moved in the pushing direction onto the flap. The stop must be flexible and deformable here and/or the items themselves must be capable of being temporarily deformed. 
   It has to be noticed that U.S. Pat. No. 4,398,383 discloses a device for packing items in a box. This device is provided with a pressure plate which can tilt about a pivot and is not movable in a horizontal direction transversely to a conveyance direction of the items. The device according to this American patent is provided with a stop that pivots by means of a drive. A disadvantage of such a pivoting stop is that a separate drive is needed for it, the control of which drive must be synchronised with the movement of the pressure plate. 
   One embodiment of the device according to the invention is characterized in that the pressure plate can be passed underneath the stop. 
   Such a movement is possible, for example, if the height of the pressure plate is less than the distance between the stop and the flap, so that the pressure plate can be passed underneath the stop without any hindrance. 
   The stop can be a strip extending transversely to the guide plate, a bar extending transversely to the guide plate, or a bar extending parallel to the guide plate, it being so that in each embodiment of the stop, said stop in an easy and efficient manner prevents the article from accidentally swinging or falling in the direction of the pressure plate. 
   Another embodiment of the device according to the invention is characterised in that the pushing device is provided with a stop plate connected to the pressure plate and extending transversely to the pressure plate. 
   The stop plate connected to the pressure plate ensures that during the movement of items on the flap, following items moving in the conveyance direction are retained. During the return movement of the stop plate to the initial position, these items are moved further in the conveyance direction by the conveyor until said items are situated opposite the pressure plate. Through the combination of the pressure plate and the stop plate, a simple, reliable device is obtained. 
   Yet another embodiment of the device according to the invention is characterised in that the conveyor is provided with guides for guiding upright bags having a top seam, the top seam extending virtually parallel to the conveyance direction. 
   The bags are held in the upright position by the guides, so that the bags cannot accidentally fall over. 
   It is pointed out that in the case of the device according to the abovementioned American patent U.S. Pat. No. 4,864,801 the bags first fall over and are then moved back into a substantially upright position by the plate disposed at an angle. There is a risk here of a bag falling under another bag and ultimately being, as it were, upside down, which is, of course, undesirable. This also makes the reliability and accuracy of this device limited. 
   Yet another embodiment of the device according to the invention is characterised in that the guide plates extend virtually parallel to each other. 
   Owing to the fact that the guide plates extend virtually parallel to each other, items once placed on the flap will have virtually no space to shift in relation to each other, so that good positioning of the objects relative to each other is ensured. 
   Another embodiment of the device according to the invention is characterised in that the guide plates, at least near the pushing device, can be moved away from and towards each other. 
   For movement of items between the guide plates, the guide plates are preferably moved away from each other at least near the pushing device, so that the items can be positioned between the guide plates in a simple manner. On a side facing away from the pushing device, the guide plates do not need to be moved away from each other, and can be at the ultimate desired distance from each other, the items being moved a little more towards each other while they are being moved in the pushing direction by the guide plates. After all items have been placed on the flap, the guide plates are moved towards each other, with the result that the items are pressed firmly against each other by the guide plate. In the process, the items are also pressed against each other between the pressure plate and the retaining plate, with the result that a good configuration of items is obtained, which items, simply by opening the flap, will then fall into a box standing below the flap. 
   Yet another embodiment of the device according to the invention is characterised in that one of the guide plates forms a stop for a bag supplied by means of the conveyor. 
   In this way the guide plate forms both a stop for items moving in the conveyance direction and a guide for items moving in the pushing direction. This makes the construction of the device relatively simple. 
   Yet another embodiment of the device according to the invention is characterised in that the flap comprises at least two supporting plates that are movable in a plane away from and towards each other. 
   Having supporting plates moving away from each other means that the box can be situated a relatively short distance below the flap, with the result that the distance that the items standing ready on the flap have to be moved into the box is relatively short. 
   With fully pivoting supporting plates, such as those used according to the abovementioned American patent U.S. Pat. No. 4,864,801, the items have to be moved a relatively great distance because of the space required for pivoting the supporting plates. Because of the relatively great distance, there is a risk here of damage to the products present in the items. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be explained in greater detail with reference to the drawings, in which: 
       FIG. 1  is a perspective view of a first embodiment of a device according to the invention; 
       FIG. 2  shows the device illustrated in  FIG. 1  at a different phase of the filling of a box with bags; 
       FIG. 3  is a perspective view of the device illustrated in  FIG. 1  in yet another phase of the filling of a box with bags; 
       FIG. 4  is a perspective view of a second embodiment of a device according to the invention; 
       FIG. 5  shows the device illustrated in  FIG. 4  during a different phase of the filling of a box; 
       FIG. 6  is a perspective view of the device illustrated in  FIG. 4  during yet another phase of the filling of a box with bags. 
   

   Corresponding parts are provided with the same reference numeral in the figures. 
   DETAILED DESCRIPTION OF THE DRAWINGS 
     FIG. 1  shows a first embodiment of a device  1  according to the invention, which is provided with a conveyor  2  comprising an endless conveyor belt  3  and also two guides  4  extending parallel to each other. Situated opposite one end of the conveyor  2  is a guide plate  5  extending transversely to said conveyor. A second guide plate  6  extends parallel to the guide plate  5 . The guide plates  5 ,  6  extend transversely to two supporting plates  7 ,  8 , which are movable in a plane away from and towards each other. The supporting plates  7 ,  8  form a flap  9 , which can be moved from a closed position shown in  FIG. 1  to an open position shown in  FIG. 3 . Disposed below the flap  9  is a further conveyor  10 , which extends transversely to the conveyor  2 , which conveyor  10  comprises an endless belt  11  and two guides  12  extending parallel to the endless belt  11 . The device  1  furthermore comprises a pushing device  13 , which comprises a pressure plate  14  extending transversely to the guide plates  5 ,  6 , and a stop plate  15  extending parallel to the guide plates. The pressure plate  14  together with the stop plate  15  can be moved by means of a pneumatic device  16  in a direction opposite to the direction indicated by arrow P 1 . The device  1  additionally comprises a retaining plate  17  situated between the guide plates  5 ,  6 , which retaining plate at the side facing away from the flap  9  is connected to a slide  18 , which can be moved along a rail  19  by means of a drive (not shown) in a direction opposite to the direction indicated by arrow P 2 . A bar (not shown) extends between the guide plates  5 ,  6 , which bar acts as a stop and is situated at a distance above the flap  9  that is less than the height of the bags  20  to be packed. 
   By means of the conveyor  2 , bags  20  are movable in the direction indicated by arrow P 3 , in the direction of the guide plate  5 . The bags  20  are in an upright position, longitudinal sides  21  of the bags resting against the guides  4 . A top longitudinal seam  22  of the bag extends parallel to the conveyance direction indicated by arrow P 3 . Owing to the fact that the bags  20  rest with both longitudinal sides  21  against the guides  4 , the bags  20  are well supported and have no tendency to fall over. 
   By means of the conveyor  10 , boxes are moved in the direction indicated by arrow P 4 . 
   In the situation shown in  FIG. 1  an empty box  23  is present below the flap  9 , a number of rows of bags  20  having to be placed in the box  23 . 
   The device  1  works as follows: 
     FIG. 1  shows the situation in which no bag  20  at all is yet on the flap  9 . A bag  20  is moved in the direction indicated by arrow P 3 , until the bag  20  is resting against the guide plate  5 . The retaining plate  17  here is in a position virtually parallel to the guide  4  and near an end of the guide plate  6  situated opposite the pressure plate  14 . The pressure plate  14  here is in a position parallel to the other guide  4 . Through these positions of the pressure plate  14  and the retaining plate  17 , the bag  20  is positioned accurately resting against the guide plate  5 , without risk of falling over or tilting. A second bag is then conveyed by means of the conveyor  2  in the direction indicated by arrow P 3 , until said second bag is resting against the first bag. A row of bags comprising two bags has now been formed. By means of a control unit, the pressure plate  14  is then moved by the device  16  in the direction indicated by arrow P 1 , so that the bags resting against the pressure plate  14  are also moved in the direction indicated by arrow P 1 . Simultaneously with the movement of the pressure plate  14 , the retaining plate  17  is moved in the direction indicated by arrow P 2 . The row of bags is held firmly between the retaining plate  17  and the pressure plate  14  here, so that the bags  20  cannot fall over. The bags  20  are passed underneath the bar here, during which the upper side of the bags  20  is elastically deformed. At the head end of the bags, the bags  20  are guided by the guide plates  5 ,  6 . In this way the orientation of the bags  20  is clearly determined by the retaining plate  17 , the pressure plate  14  and the guide plates  5 ,  6 . Once the pressure plate  14  is in a position near the guide plate  6 , the stop plate  15  extends virtually in line with the guide plate  6  (see  FIG. 2 ), and following bags  20  that are being transported in the direction indicated by arrow P 3  are retained by stop plate  15 . After the pressure plate  14  has moved in the direction indicated by arrow P 1  over a distance that virtually corresponds to the width of the bags  20 , the pressure plate  14  is moved in a direction opposite to arrow P 1  until the pressure plate  14  again assumes the position shown in  FIG. 1 . The bar prevents the bags  20  from falling over in the direction opposite to arrow P 1 . 
   Two new bags are then conveyed in the direction indicated by arrow P 3  until the front bag is resting against the guide plate  5 . After that, the pressure plate  14  is again conveyed in the direction indicated by arrow P 1 , so that a row of two bags is again placed on the flap  9 . The retaining plate  17  is moved simultaneously with the movement of the pressure plate  14 , so that the row placed earlier is also moved in the direction indicated by arrow P 1 . 
   After a desired number of rows of bags has been placed on the flap  9 , the rows of bags are pressed firmly against each other by the pressure plate  14  (see  FIG. 2 ). While they are being pressed against each other, following bags  20  moving in the direction indicated by arrow P 3  are retained by the stop plate  15 . 
   Subsequently, as shown in  FIG. 3 , the supporting plates  7 ,  8  are moved away from each other in the directions indicated by arrows P 5 , P 6 , with the result that the bags  20  are no longer supported and, under the influence of gravity, fall in the direction indicated by arrow P 7  into the box  23  standing ready below the flap. Owing to the fact that the box  23  is situated directly below the supporting plates  7 ,  8  that are moving away from each other, the distance over which the bags  20  are moved in the direction indicated by arrow P 7  is relatively short. 
   The guide plates  5 ,  6 , the retaining plate  17  and the pressure plate  14  are preferably relatively smooth, so as to limit friction between the plates and the bags. 
     FIGS. 4-6  show a detail of a second embodiment of a device  31  according to the invention, which is provided with a conveyor  32  comprising an endless conveyor belt  33  and two guides  4  extending parallel to the conveyor belt  33 . 
   The device  31  is additionally provided with a drive  36 , by means of which one end of the guide plate  6  situated opposite the pressure plate  14  can be moved in a direction opposite to the direction indicated by arrow P 8 . 
   The device  31  is provided with a stop  37  extending transversely to the guide plate  5 . The stop  37  extends up to the guide plate  6 . The stop  37  is made of a flexible deformable material such as, for example, a brush connected to a metal strip. The brush prevents bags on either side of the stop  37  from falling over. The distance of the brushes from the flap is less than the height of the bag here. A force is exerted upon the brush by the bags  20  while the pressure plate  14  is being moved in the direction indicated by arrow P 1 , with the result that the brush is deformed and the bags can be moved from one side of the stop  37  to the other side of the stop  37  without damage occurring to the bags in the process. During this process the pressure plate  14  is passed underneath the stop  37 . 
   The mode of operation of the device  31  is largely similar to that of the device  1  described above. One difference is that during the formation of a number of rows on the flap  9  the end  38  of the guide plate  6  is moved away from the guide plate  5  in a direction opposite to that of arrow P 8 , with the result that the distance between the guide plates  5 ,  6  is relatively great near the end  38 , so that a row of bags can easily be pressed in between the guide plates  5 ,  6 . The distance between the guide plates  5 ,  6  on a side facing away from the pressure plate  14  is preferably equal to the desired distance. During the movement in the direction indicated by arrow P 1  the bags are also pressed towards each other here. As soon as the desired number of rows is formed on the flap  9 , the end  38  of the guide plate  6  is moved in the direction indicated by arrow P 8 , so that all bags are positioned in the same way on flap  9 . As shown in  FIG. 6 , the flap  9  is then opened, and the bags fall in the direction indicated by arrow P 7  into the box  23  standing ready below the flap  9 . 
   It is also possible to move the entire plate  6  in and opposite to the direction indicated by arrow P 8 . 
   It is also possible to provide the guide plates  5 ,  6  with special coatings or materials in order to reduce the friction between the bags and the guide plates. 
   It is also possible not only to place the bags in the boxes under the influence of gravity, but also to push the bags into the box by means of a plate pressing upon the bag from the upper side. 
   It is also possible to provide the flap  9  with hinged supporting plates. However, this means that the distance that the bags have to cover in the direction indicated by arrow P 7  is greater. 
   It is also possible to form rows of more than two bags, or to form a ‘row’ of only a single bag. 
   It is also possible to supply the bags separated, in which case the stop plate may be dispensed with, if desired. 
   In the case of relatively flexible bags it is also possible to make the stop rigid, in which case the bags themselves are deformed briefly while they are being moved past the stop. 
   It is also possible to make the stop in the form of a tensioned elastic wire extending parallel to or transversely to the pressure plate, or having another orientation relative to the pressure plate, the wire or wires resting against the upper side of the bags, with the result that the bags are prevented in a simple manner from falling over. 
   It is also possible to move the bags in the conveyance direction, in which case the top seam, for example, is positioned transversely to the conveyance direction. 
   The guide plates can also be in the form of endless conveyor belts extending in the direction of the box to be filled. The guide plates can also comprise air bearings, balls or rollers. In the case of such guide plates the friction between the guide plates and the items to be packed is relatively low. 
   It is also possible to make the supporting plates  7 ,  8  pivoting, or to make them undergo another type of movement in order to open the flap. 
   The retaining plate, the pressure plate and the guide plates can be disposed in a slightly conical arrangement, so that when the items fall into the box contact with the plates is reduced relatively rapidly. 
   The retaining plate is moved simultaneously with an item in the pushing direction. The speed can be the same here as that of the item, or it can be slightly slower, so that the item is compressed slightly.