Abstract:
A single sheet collecting device for stacking sheets of paper or plastic has at least one transport element and at least one stop unit arranged in a transport path of the sheets. First and second deflecting parts are arranged along the transport path of the sheets for moving the sheets during transport for a moment out of a transport plane of the sheets. The first and second deflecting parts are adjustable from a first position for top stacking the sheets into a second position for bottom stacking the sheets and vice versa.

Description:
BACKGROUND OF INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The invention relates to a single sheet collecting device for stacking sheets of paper, plastic or the like, wherein the collecting device comprises at least one, preferably several, transport elements, especially transport belts, at least one-stop unit positioned in the transport path of the sheets, and at least one first deflecting part with which the sheets during transport can be briefly lifted or moved out of their transport plane.  
           [0003]    2. Description of the Related Art  
           [0004]    In order to stack sheets, they must be stacked, depending on the feeding devices, underneath or on top of the already formed stack or of the first sheet for starting the stack. When performing a top stacking process, sequentially supplied sheets are stacked on top one another to form a set or stack of sheets. When performing a bottom stacking process, the following sheet is pushed underneath the bottom sheet of the already stack or the first sheet for starting the stack. In both situations, the sheets must be moved (lifted or lowered) out of the transport path or plane. For this purpose, deflecting parts in the form of wedge-shaped ramps are used. Depending on the stacking sequence, the ramps must be removed and mounted at a different location. The required retooling process is complex and difficult.  
         SUMMARY OF INVENTION  
         [0005]    It is an object of the present invention to configure a device of the aforementioned kind such that the device can be retooled for top stacking or bottom stacking of sheets in a simple way and in a very short period of time.  
           [0006]    In accordance with the present invention, this is achieved in that the first deflecting part has at least one second deflecting part correlated therewith and in that the first and second deflecting parts are adjustable from a position for top stacking of the sheets into a position for bottom stacking of the sheets and vice versa.  
           [0007]    In the collecting device according to the present intention, the two deflecting parts can be simply adjusted into the required position for top stacking or bottom stacking. Removal or demounting of a deflecting part is not required for retooling so that the collecting device can be retooled within a very short period of time. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0008]    [0008]FIG. 1 illustrates schematically in a side view a collecting device according to the invention for collecting sheets of paper, plastic, or the like, comprising a deflecting device for the sheets for top stacking.  
         [0009]    [0009]FIG. 2 shows the device of FIG. 1 in a view in direction of arrow II of FIG. 1.  
         [0010]    [0010]FIG. 3 shows the device according to FIG. 1 in a position where a second sheet is guided onto a first sheet.  
         [0011]    [0011]FIG. 4 illustrates schematically the collecting device according to FIG. 1 wherein the deflecting device is positioned for carrying out bottom stacking.  
         [0012]    [0012]FIG. 5 is a view analog to FIG. 2 but illustrating the deflecting device in a position for bottom stacking.  
         [0013]    [0013]FIG. 6 is a view analog to FIG. 3 but showing a position where a second sheet is guided underneath a first sheet (bottom stacking). 
     
    
     DETAILED DESCRIPTION  
       [0014]    With the collecting device  1  according to FIG. 1, individual sheets A, B, preferably paper sheets, are collected to form stacks or sets and are subsequently fed to a further processing device. The collecting device  1  is an accumulator which at the intake side and at the exit side comprises two shafts (not illustrated), respectively. Transport belts  2  to  5  extend about these shafts and have a round cross-section. In the embodiment according to FIG. 1, two transport belts  2  and  4  are positioned underneath the transport plane farther outwardly than the two transport belts  3  and  5 . The belts  3 ,  5  are positioned inwardly relative to the transport belts  2  and  4  (between the transport belts  2  and  4 ) and are spaced relative to one another by a much greater spacing than the spacing to the neighboring transport belts  2  and  4 , respectively.  
         [0015]    By means of the transport belts  2  to  5 , the paper sheets A, B are transported in a way known in the art by the device  1  in the transport direction P. The paper sheets A, B are positioned between the transport belts  2  to  5  and entrained by them. In the area between the forward and rearward shafts of the transport belts  2  to  5 , viewed in the transport direction P, a stop unit  6 ,  7  is provided which is preferably adjustable relative to the transport direction P. Such stop units are comprised of rollers  6  and  7  stacked atop one another and operated in opposite rotational directions. The rollers  6 ,  7  stand still during stacking of the paper sheets A, B. The first paper sheet A is positioned with its leading edge in the transport direction P in the gap between the stacked rollers  6 ,  7  and is positioned with its rearward portion between the transport belts  2  to  5 . When viewed in the transport direction P, a deflecting device  8  is arranged behind the shafts for the transport belts  2  to  5  at the intake side and in front of the stop unit  6 ,  7 ; it serves as a ramp for top stacking or bottom stacking of the paper sheets A, B.  
         [0016]    In the illustrated embodiment, the device  8  has two first and two second deflecting parts in the form of deflecting rollers  9 ,  10  and  11 ,  12  which have circumferential grooves  13 ,  14  and  15 ,  16  (FIG. 2) for the transport belts  2  to  5 . The circumferential grooves  13 - 16  in the illustrated embodiment have a depth which corresponds approximately two twice the diameter of the transport belts  2  to  5 .  
         [0017]    The first rollers  9 ,  10  and the second rollers  11 ,  12  are seated on an axle  17  and  18 , respectively, having ends are supported on an arm  19 ,  20  of the deflecting device  8 . The arms  19 ,  20  are preferably identical and formed by rectangular plates. The first rollers  9 ,  10  are seated on the axle  17  at a spacing from one another which is slightly greater than the spacing of the rollers  9 ,  10  from the arms  19  and  20 . The spacing of the rollers  11  and  12  from the neighboring arms  19  and  20  is somewhat smaller than that of the rollers  9 ,  10  relative to these arms  19 ,  20 . The arms  19 ,  20  are supported to be pivotable about an axis  21  in the collecting device  1  and arranged approximately at the level of the transport plane for the paper sheets A, B. The pivot axis  21  is positioned approximately at half the length of the arms and approximately at half the width of the arms between the longitudinal center plane L of the arms  19 ,  20  and a neighboring longitudinal edge  22  of the arms  19 ,  20  (FIGS. 1, 4).  
         [0018]    The two arms  19 ,  20  are positioned on opposite sides of the transport belts  2  to  5  at a spacing to the transport belts  2  to  5 . The axles  17 ,  18  and the pivot axis  21  are positioned parallel to one another and perpendicular to the parallel extending transport belts  2  to  5 . The axles  17 ,  18  are positioned in an area above and underneath the transport belts  2  to  5 . The deflecting device  8  is pivoted about the axis  21  for top stacking (FIGS.  1  to  3 ) of the paper sheets A, B such that, viewed in the transport direction P, the upper rollers  11 ,  12  are moved forwardly relative to the lower transport rollers  9 ,  10  in the transport direction P. The arms  19 ,  20  are accordingly forwardly and upwardly slanted in the transport direction P.  
         [0019]    The upper rollers  11 ,  12  are positioned at the level of the lower transport belts  2 ,  4  and are arranged such that the paper sheets A, B are positioned tangentially relative to the rollers  2 ,  4 . The lower rollers  9 ,  10  are positioned at the level of the upper transport belts  3 ,  5  and are arranged such that the transport belts  3 ,  5  engage completely the grooves  13 ,  14  of the rollers  9 ,  10 .  
         [0020]    When the paper sheets A, B are to be bottom stacked, the deflecting device  8  is pivoted in the clockwise direction about the axis  21  into the position illustrated in FIG. 4 in solid lines. Now the lower rollers  9 ,  10  are forwardly moved relative to the upper rollers  11 ,  12  in the transport direction P of the paper sheets A, B. The arms  19 ,  20  are slanted upwardly to the rear when viewed in the transport direction P. The upper transport belts  3 ,  5  are arranged relative to the lower rollers  9 ,  10  such that the paper sheets A, B rest tangentially against the rollers  9 ,  10 . The upper rollers  11 ,  12  have been lowered such that the lower transport belts  2 ,  4  engage completely the grooves  15 ,  16  of the rollers  11 ,  12 .  
         [0021]    Depending on whether the device is to be used for bottom stacking or top stacking of the paper sheets A, B, the arms  19 ,  20 , neighboring one another and connected to one another by means of the bearing axles  17 ,  18 , can be pivoted such that they can be moved from the position according to FIGS.  1  to  3  into the position according to FIGS.  4  to  6 . The pivot movement of the deflecting device  8  is performed preferably by means of a motor operator (not illustrated) with which a shaft comprising the pivot axis  21  is rotatably driven. The deflecting device  8  is adjustable in and counter to the transport direction P for adjustment to different lengths of the paper sheets A, B. Advantageously, a motor operator is used also for this purpose with which the deflecting device  8  is movable along a guide (not illustrated).  
         [0022]    The paper sheets A, B are laterally guided through stops (not illustrated). In order to be able to reliably transport paper sheets of different widths, these stops are advantageously adjustable automatically by means of motor operators in a direction transverse to the transport direction.  
         [0023]    The different motor operators are connected to a control device and are actuated by program control. The precise position of the deflecting device  8  is controlled advantageously such that the actual position of the deflecting device  8  is compared by means of potentiometers with the predetermined nominal position. As soon as the deflecting device  8  has reached its nominal position, the corresponding motor operators are switched off.  
         [0024]    Advantageously, the adjusting data, such as length and width of the paper sheets A and/or B, bottom stacking and top stacking actions of the sheets, are saved in a data storage device (memory). These data can be easily retrieved so that the deflecting device  8  can be adjusted automatically into the required position.  
         [0025]    In this way, with minimal construction expenditure an automation of the device  8  can be achieved so that the device provides optimal flexibility.  
         [0026]    At the beginning of top stacking of the paper sheets A, B (FIGS.  1  to  3 ), the first paper sheet A is transported by means of the transport belts  2  to  5  in the direction P to such an extent that its leading edge (in the transport direction P) contacts a stop unit  6 ,  7  whose rollers are standing still. The deflecting device  8  is adjusted such that the sheet A in its stop position is located with its rearward or trailing edge  24  (viewed in the transport direction P) in the area between the upper and lower rollers  11 ,  12  and  9 ,  10  (FIG. 3). Moreover, the rollers  9  through  12  are arranged such that the paper sheet A projects laterally past the rollers (FIG. 2). In the top stacking action, the two lower rollers  9 ,  10  have been lifted in the described way past the transport plane such that the transport belts  3 ,  5  are immersed in the grooves  13 ,  14 . This has the result that the paper sheets A, B move onto the arc-shaped curved edge  25  of the rollers  9 ,  10  and are deflected upwardly, as illustrated in the FIG. 3 for the paper sheet B. The upper transport belts  3 ,  5  are pushed elastically upwardly so that the paper sheet is transported across the rollers  9 ,  10 . The paper sheet is pushed by the elastically bent transport belts  3 ,  5  against the rollers  9 ,  10  and is thus reliably held in place.  
         [0027]    The rollers  9 ,  10  are arranged such that the upper transport belts  3 ,  5  are deflected to such an extent that in the transport direction P they are returned into the transport plane behind the rollers  11 ,  12 . The paper sheet B reaches with its leading edge  23  the paper sheet A (FIG. 3) at a spacing to the rearward edge  24  of sheet A.  
         [0028]    The upper and lower rollers  11 ,  12  and  9 ,  10  are displaced relative to another in the transport direction P such that the paper sheet B with its leading edge  23  reaches the area between the lower transport belts  3 ,  5  and the upper rollers  11 ,  12  as long as it is positioned with its rearward portion between the upper deflected transport belts  3 ,  5  and the lower rollers  9 ,  10 . The paper sheet is thus reliably held in place at anytime during its transport.  
         [0029]    In the described way, all paper sheets A, B are transported through the deflecting device  8 . As soon as the paper sheet set or stack has been completed, the rollers  6 ,  7  are driven and the set is transported farther between the rollers  6 ,  7  as is known in the art. As soon as the rollers  6 ,  7  are stopped again, the next set or stack of paper sheets can be produced by top stacking the paper sheets as described above.  
         [0030]    When the set of paper sheets is to be formed by bottom stacking, the deflecting device  8  is pivoted in the described way from the position according to FIGS.  1  to  3  into the position according to FIGS.  4  to  6 . The paper sheets A, B guided between the transport belts  2  to  5  move onto the edge  26  of the upper rollers  11 ,  12 . Since the lower transport belts  2 ,  4  engage the grooves  15 ,  16  of the upper rollers  11 ,  12 , the paper sheets A, B are deflected by the arc-shaped edge  26  of the upper rollers  11 ,  12  in the downward direction (FIG. 6). The lower transport belts  2 ,  4  are elastically bent downwardly such that they move into the grooves  15 ,  16  of the upper rollers  11 ,  12 .  
         [0031]    The paper sheet A is positioned on the rollers  6 ,  7 . Its rearward edge  24  is positioned in the area between the lower and the upper rollers  9 ,  10  and  11 ,  12  (FIG. 6). In this area, the lower transport belts  2 ,  4  are deflected downwardly such that the following paper sheet B with its forward edge  23  is moved underneath the paper sheet A. The paper sheet B is transported to the rollers  6 ,  7 . In this way, the paper sheets A, B can be transported sequentially underneath the already stacked set of paper sheets.  
         [0032]    As in the situation of top stacking (FIGS.  1  to  3 ), the paper sheets A, B are reliably held in their stack position at the rollers  6 ,  7  by the transport belts  2  to  5  which rest against the paper sheets A, B in the area between the rollers  6 ,  7  and the neighboring rollers  11 ,  12  (FIGS.  1  to  3 ) or rollers  9 ,  10  (FIGS.  4  to  6 ), respectively.  
         [0033]    In the situation of top stacking according to FIG. 1 to  3 , the upper rollers  11 ,  12  act as holding-down devices on the incoming sheet. In the situation of bottom stacking according to FIGS.  4  to  6 , the lower rollers  9 ,  10  serve as supports for the incoming sheet.  
         [0034]    In order to achieve a simple adjustment of the deflecting device  8 , it is pivoted against stops (not illustrated). The deflecting device  8  can also be retrofitted into already existing devices and can replace the ramps which are present in the devices to be retrofitted.  
         [0035]    While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.