Patent Publication Number: US-6699165-B1

Title: Apparatus for removing and transferring folding boxes

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a 35 USC 371 application of PCT/DE 00/00081 filed on Jan. 12, 2000. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to an apparatus for removing and transferring folding box blanks in a folding box erecting apparatus. 
     2. Description of the Prior Art 
     German Patent DE 27 20 902 C2 discloses apparatus for removing and transferring folding boxes in which the pivotable suction cups that pull the folding box blank out of the folding box magazine engage a lower folding box wall, in terms of the erected folding box, that is parallel to the feeding direction. Since the folding box inserted between the drivers of the conveyor system which is in continuous motion is located above the suction cups, the suction cups, in order to remove the next folding box blank from the folding box magazine as soon as possible, must be moved backward horizontally by a certain distance, while at the same time the erected folding box is moved onward by the conveyor system. To attain high output in a conveyor system operating incrementally, a very long horizontal return stroke of the suction cups, which can be achieved only with relative difficulty, would be necessary if the withdrawal of the next folding box blank is to take place during the standstill phase of the conveyor system. Moreover, because of the disposition of its fixed erecting shunt, the known apparatus is suitable only for erected folding box blanks whose front upper edge (in terms of the erected folding box) is disposed at the front in the folding box magazine, in terms of the feeding direction. 
     From German Patent Disclosure DE 39 41 866 A1, a transfer apparatus is also known which has a suction rotor that moves along a cycloidal path. Such an apparatus is very complicated in design, because of the requisite complex paths of motion with planetary gears. 
     SUMMARY OF THE INVENTION 
     The apparatus according to the invention for removing and transferring folding boxes has the advantage over the prior art that even folding box blanks in which the lower, front edge, in terms of the erected folding box in the feeding direction, is disposed at the front in the folding box magazine can be handled. At the same time, the apparatus has a relatively high output, since regardless of the motion of the conveyor system, even with a conveyor system operated incrementally, the suction device can be pivoted immediately after the transfer of the folding box to between the drivers of the conveyor system, without a horizontal return stroke, for removal of the next folding box blank. 
     To facilitate the erection and to prevent shear forces from changing the position of the folding box blank at the suction cup, a support prong can be provided. 
     It is especially advantageous to provide additional suction cups, which are disposed in coincidence with a lower folding box wall, in terms of the erected folding box. This makes better, more secure removal of the folding box blanks from the folding box magazine possible. This is especially advantageous in the case of relatively large folding boxes, which as a result cannot open prematurely, making it possible to prevent the setting-up motion from allowing the folding boxes to press into the stack of folding box blanks in the folding box magazine. 
     The course of motion of the multi-bar linkage mechanism can be controlled especially exactly if the multi-bar linkage mechanism is driven by a servo motor. 
     An especially high output and uniform opening of the folding boxes is attained if the insertion takes place during the advancement phase of a conveyor system driven incrementally, and the leading edge of the folding box blank is operatively connected to a driver of the conveyor system. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     One exemplary embodiment of the invention is shown in the drawing and will be described in further detail below, with reference to the drawings, in which: 
     FIGS. 1-3 show an apparatus for removing and transferring folding boxes, in simplified side views during various phases of motion. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In FIG. 1, reference numeral  10  indicates an apparatus for removing folding box blanks  1 , lying flat, from a folding box magazine  11  and transferring them, while erecting them at the same time, between cleat-like drivers  12 ,  13  of a conveyor system  15  driven in increments. The conveyor system  15  is preferably constructed of rack profiles  16 , and the drivers  12 ,  13  are integrally connected to the rack profiles  16 . Because of the integral nature, the top side  17  of the rack profiles  16  forms a flat bearing face for the erected folding boxes  2 . The structure of this kind of conveyor system  15  is described in further detail in German Patent Disclosure DE 197 31 084 A1. 
     The folding box magazine  11 , disposed above the deflection region of the conveyor system  15 , has two side walls  18 ,  19  that are angled in the upper region. Retention baffles  21 , for the lowermost folding box blank  1  in each case, are disposed on the vertically erected, lower end  20  of the folding box magazine. The folding box blanks  1 , forming a stack one above the other in the folding box magazine  11 , have two wide side walls  22  and two narrow side walls  23 , which are variously joined together by way of edges  24 ,  25 ,  26 ,  27 . The folding box blanks  1  are all placed flat in the folding box magazine  11  in such a way that the front lower edge  27  of the folding box  2  in terms of the erected folding box  2  in the feeding direction  28 , contacts the front side wall  19  of the folding box magazine  11 . 
     Between the folding box magazine  11  and the deflection region of the conveyor system  15 , the apparatus  10  has a suction rotor  30 . The suction rotor  30  is embodied in the form of a multi-bar linkage mechanism, and in the exemplary embodiment shown as a four-bar mechanism  31 . To illustrate the component parts of the four-bar mechanism, a crank  32 , coupler  33  and connecting rod  34  are indicated schematically. The crank  32  is coupled to a servo motor  37  via a drive wheel  35  and a toothed belt  36 . While the crank  32  and the connecting rod  34  are embodied as shackles  38 , the coupler  33  has a bearer  39 , which is approximately triangular in side view and has an extension  40 . Two rows, preferably each with a plurality of suction cups  41 ,  42  located parallel to the plane of FIG. 1, are secured to the extension  40 . The suction cups  41  and the suction cups  42  are connected to at least one source of negative pressure, not shown, via connections  43 ,  44  disposed on the bearer  39 , in such a way that the suction cups  41 ,  42  can be subjected to negative pressure separately. What is essential is that one group of suction cups  41  engages one rear, narrow side wall  23  of the folding box blank  1 , while the other suction cups  42  engage one lower, wide side wall  22  of the folding box blank  1 . Also, the suction cups  41  at the narrow side wall  23  directly engage the edge  24 , which has the advantage that folding boxes  2  with narrow side walls  23  of different heights can be handled without adjusting the suction rotor  30 . 
     Also disposed on the bearer  39  is a stationary support prong  45  with a stop  46  for the folding box blank  1 ; it directly engages the upper, rear edge  25 , in terms of the erected folding box  2 . To facilitate the erecting of the folding box  2  and at the same time form a guide for the folding box  2 , a stationary erecting shunt  47  is disposed in the deflection region of the conveyor system  15 . The erecting shunt  47  has a curved guide path  48 , which extends up to the level of the top side  17  of the rack profiles  16  and forms a smooth transition from the guide path  48  to the rack profiles  16 . Finally, the drivers  12 ,  13  of the conveyor system  15  cooperate in the region of the upper feed path with a cover rail  50 . Together with the drivers  12 ,  13  and the top side  17  of the rack profiles  16 , the cover rail  50  that dips between the drivers  12 ,  13  forms a rectangular cross section in side view, within which cross section the erected folding box  2  is disposed with positive engagement. The cover rail  50  extends to approximately below one side wall  19  of the folding box magazine  11 , and on its end toward the suction rotor  30 , on the side toward the top sides  17  of the rack profiles  16 , it has a chamfer  51 . 
     The apparatus  10  described above functions as follows: For pulling the bottommost folding box blank  1  out of the folding box magazine  11 , the operative faces of the suction cups  41 ,  42  are oriented horizontally; one group of suction cups  41  engages the narrow side wall  23  of the folding box blank  1 , while the other suction cups  42  engage the wide side wall  22  of the folding box blank  1  (FIG.  1 ). Once the suction cups  41 ,  42  have been subjected to negative pressure, the suction cups  41 ,  42  are moved downward, because of the motion of the suction rotor  30 , and at the same time are pivoted clockwise, whereupon the folding box blank  1  is pulled out of the folding box magazine  11 . Next, the leading edge  27  of the folding box blank  1  enters into contact with the erecting shunt  47 . Because of the oblique position of the suction cups  41 , the folding box blank  1  thereupon begins to erect itself. If a force component occurs in the direction of the narrow side wall  23  resting on the suction cups  41 , then displacement of the folding box blank  1  on the suction cups  41  is prevented by the stop  46  of the support prong  45 , even if only relatively slight negative pressure is applied to the suction cups  41 . What is essential here is that during the erection, the suction cups  42  are no longer subjected to negative pressure, so that the wide side wall  22  can be folded out of the plane of the narrow side wall  23 . In the ensuing motion of the suction rotor  30 , during which the suction rotor moves partway between the rack profiles  16  and its drivers  12 ,  13 , the leading edge  27  moves along the guide path  48  and finally reaches the top side  17  of the rack profiles  16  (FIG.  2 ). It is also essential that the transfer or insertion of the folding box blank  1  to between the drivers  12 ,  13  occurs while the incrementally driven conveyor system  15  is just being moved onward by one feeding increment, and the rack profiles  16  are thus in motion at that time. The motion of the suction rotor  30  is adapted to the advancement of the rack profiles  16  in such a way that the front, lower edge  27  of the folding box blank  1  runs up against the leading driver  12 . As a result, the folding box blank  1  is diagonally fixed between the rack profiles  16  and the leading drivers  12  on the one hand and the support prong  45  on the other. In addition, the erection motion is generated via the pivoting suction cups  41 . 
     In FIG. 3, the situation is shown just before the folding box blank  1  has been completely erected. The front edge  27  rests on the leading drivers  12 , and the folding box blank  1  is moved by the suction rotor  30  at a speed corresponding to the speed of the rack profiles  16 . In addition, the upper, wide side wall  22  is guided by the cover rail  50 , and the trailing drivers  13  are located near the rear, narrow side wall  23 . 
     For the sake of security, the folding box blank  1  is retained by the suction cups  41  during the entire advancement motion of the rack profiles  16 . As soon as the conveyor system  15  is at a standstill, the trailing drivers  13  are also in contact with the rear, narrow side wall  23 , so that the folding box  2  is received by positive engagement by the conveyor system  15  and the cover rail  50 . Now the negative pressure at the suction cups  41  is shut off, and in order to pull out the next folding box blank  1  from the folding box magazine  11 , the suction rotor  30  is moved in the direction of the magazine. 
     The apparatus  10  can be modified in manifold ways. It is understood that it can also be used with conveyor systems that move continuously. In that case, the release of the folding box blank  1  can take place as soon as the folding box is located between the drivers  12 ,  13 . In addition, the suction cups  42  engaging the wide side wall  22  can be omitted, if the narrow side wall  23  is wide enough for one or more powerful suction cups  41 . 
     The foregoing relates to preferred exemplary embodiment of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims.