Abstract:
For converting a stream of flat articles from transverse conveyance to parallel conveyance, two continuously operated conveyors are provided, a transverse conveyor having a direction (FQ) of transverse conveyance and serving as supplying conveyor and a parallel conveyor having a direction (FP) of parallel conveyance and serving as removing conveyor. The direction (FQ) of transverse conveyance and the direction (FP) of parallel conveyance encompass an angle. The articles are pushed one after the other out of an outlet of the supplying conveyor towards an entrance of the removing conveyor. Before a trailing zone of the article has left the supplying conveyor, a leading zone of the article is grasped by an alignment device and is conveyed onwards with the speed of the parallel conveyor in the direction (FP) of parallel conveyance and is thereby aligned to the entrance ( 21 ) of the removing conveyor, while the trailing zone is bent between the alignment device and the outlet of the supplying conveyor. The stream conversion can also be operated in the reverse sense and again with continuously operated conveyors and nonetheless the articles are at all times during conversion safely guided.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The invention is situated in the field of materials handling technology and concerns a method and a device which serve for the conversion of a stream of flat articles being bendable to at least a limited degree, wherein the articles, prior to the conversion, are aligned essentially transverse to the conveying direction and, following the conversion, parallel to it or wherein the articles, prior to the conversion, are aligned parallel to the conveying direction and, following the conversion, transverse to it and wherein the flat articles, when aligned parallel to the conveying direction, are conveyed one after the other, i.e., not overlapping one another. The flat articles are in particular rectangular or square shaped; they are, for example, printed products or stack-shaped groups of component parts of multi-page printed products.  
         [0002]     In a stream in which flat articles are arranged parallel to the conveying direction and one behind the other, significantly higher conveying speeds are necessary to achieve equivalent conveying capacities than is the case for a stream, in which the articles are arranged transverse to the conveying direction. Therefore, it is a concern of materials handling technology to convey the flat articles, whenever possible, with an alignment transverse to the conveying direction or parallel to the conveying direction and overlapping one another. Such concern acquires more importance the higher conveying capacities become. However, it is frequently necessary, in particular for processing steps to be carried out on continuously conveyed articles, to align the articles one behind the other and parallel to the conveying direction. If for such cases conveyance in parallel and one behind the other is to be restricted to a necessary minimum, the article stream needs to be converted in the manner described above.  
         [0003]     The mentioned stream conversions are known to be implemented, for example, by redirecting the articles by 90°, the redirection being carried out together with a transfer from a supplying conveyor to a removing conveyor. For keeping the devices required for such conversion within a tolerable limit and for still being able to move the articles in a controlled manner during transfer and redirection, usually two conveyors are used, one of which (in most cases the supplying conveyor) is operated alternatingly. If two continuously operating conveyors are used, an at least partially uncontrolled article movement during the transfer is to be accepted.  
         [0004]     Publication U.S. Pat. No. 1,760,030 describes a transfer of glue-bound books from a binding machine to a drying machine, wherein the books are conveyed one behind the other and parallel to a first conveying direction in the binding machine and transverse to a second conveying direction in the drying machine, wherein the two conveying directions are essentially horizontal and encompass an angle of 90°, and wherein the outlet from the binding machine is located above the entrance to the drying machine. For the deviation, the books are released from holding means of the binding machine in order to drop into conveying compartments of the drying machine in an uncontrolled manner.  
       BRIEF SUMMARY OF THE INVENTION  
       [0005]     It is the objective of the invention to create a method and a device to be used for stream conversions as mentioned above, wherein the method and the device are to make it possible to implement the stream conversions with continuously operating conveying means but to move the articles in a held manner during the whole conversion and to nonetheless use simple means only.  
         [0006]     According to the invention, a continuously operating transverse conveyor having a direction of transverse conveyance is used for transverse conveyance, i.e. for conveyance with the articles being arranged transverse to the conveying direction. The transverse conveyor comprises e.g. a plurality of circulating conveying compartments being arranged essentially transverse to the direction of transverse conveyance, the flat articles being held in the compartments, for example, by gravity. Such a transverse conveyor comprises a plurality of outlets or entrances respectively, which move in the direction and with the speed of transverse conveyance. Auxiliary conveying means assigned to the transverse conveyor are e.g. arranged inside the conveying compartments and serve for displacing an article transverse to the direction of transverse conveyance while being transported by the transverse conveyor in the direction of transverse conveyance.  
         [0007]     For conveying the articles arranged parallel to the conveying direction and one behind the other (parallel conveyance), a continuously driven parallel conveyor with a direction and a speed of parallel conveyance is utilised, for example, a pair of conveyor belts, between which the articles are clamped. Such a parallel conveyor comprises one stationary entrance or stationary outlet respectively.  
         [0008]     The transverse conveyor and the parallel conveyor are both operated continuously and with the same conveying cycle (same conveying capacity). The direction of transverse conveyance and the direction of parallel conveyance are matched to one another in such a manner, that in parallel conveyance, there is a pre-defined distance between successive articles. Depending on the direction of the stream conversion (transverse conveyance to parallel conveyance or parallel conveyance to transverse conveyance), the transverse conveyor is the supplying conveyor or the removing conveyor or the parallel conveyor is the removing conveyor or the supplying conveyor respectively. In every conveying cycle there is a moment, in which an outlet or entrance of the transverse conveyor is aligned with the entrance or outlet of the parallel conveyor.  
         [0009]     The transverse conveyor, the auxiliary conveying means and the parallel conveyor are arranged in such a manner, that the conveying direction of the auxiliary conveying means is aligned parallel to the direction of parallel conveyance and that the direction of transverse conveyance encompasses an angle of, for example, 90° with the direction of parallel conveyance. During stream conversion, the auxiliary conveying means accelerates each article in the direction of parallel conveyance from standstill to the speed of parallel conveyance or decelerates it correspondingly.  
         [0010]     An alignment means is provided between the transverse conveyor and the parallel conveyor, the alignment means being aligned with the entrance of the removing conveyor and being equipped for grasping and moving articles during stream conversion in such a manner, that their leading edge is precisely aligned with the entrance of the removing conveyor and their trailing portion is bent transverse to their moving direction between the outlet of the supplying conveyor and the alignment means. For stream conversion from transverse conveyance to parallel conveyance, the alignment means is stationary and is aligned with the stationary entrance of the parallel conveyor. For stream conversion from parallel conveyance to transverse conveyance, a single means of alignment may be provided, which, in each conveying cycle, accompanies one entrance of the transverse conveyor in the direction of transverse conveyance and returns to its starting point (alternating alignment means). It is also possible to provide a plurality of correspondingly circulating alignment means or to provide one alignment means at every entrance of the transverse conveyor.  
         [0011]     The alignment means, for example, comprises a pair of alignment rollers being driven to rotate in opposite directions and having, in a part of their circumference a constant maximum radius and in the remaining part of the circumference a smaller radius. The rotation axes of the alignment rollers are aligned parallel to one another and perpendicular to the direction of parallel conveyance. The driving speed of the alignment rollers is such, that their surface speed in the zone of the maximum radius is essentially the same as the speed of parallel conveyance and that the zones of the maximum radius of both rollers are facing each other in synchronism with the conveying cycle of the transverse and the parallel conveyor. In this holding configuration the alignment rollers hold an article positioned between them and move it with the speed of parallel conveyance.  
         [0012]     The distances between the entrance or outlet of the parallel conveyor and the alignment means and the distance between the outlet or entrance of the transverse conveyor currently participating in the stream conversion and the alignment means are as small as possible and always such that, during conversion, every article is always simultaneously held either by the supplying conveyor and the alignment means or by the alignment means and the removing conveyor. This means that during the whole of the conversion, the articles are safely guided, although the supply and the removing conveyor are operated continuously and in different directions. The above mentioned distances are to be adapted to the flexibility or bendability respectively of the articles and to their expanse in the direction of parallel conveyance. 
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0013]     Exemplary embodiments of the invention are described in detail in conjunction with the following Figs., wherein:  
         [0014]     FIGS.  1  to  4  show top views of a stream conversion from transverse to parallel conveyance according to the invention;  
         [0015]     FIGS.  5  to  8  show top views of a stream conversion from parallel to transverse conveyance according the invention;  
         [0016]      FIG. 9  shows a schematic view from above of an exemplary application of a stream conversion according to FIGS.  1  to  4  for the supply of stack-shaped groups of signatures or individual sheets to a glue-binding machine;  
         [0017]      FIG. 10  shows a three dimensional partial illustration of an exemplary application of a stream conversion according to FIGS.  1  to  4  for the supply of stack-shaped groups of signatures or individual sheets to a glue-binding machine;  
         [0018]      FIG. 11  shows an exemplary embodiment of transverse conveyor and auxiliary conveying means, applicable in the method according to the invention;  
         [0019]      FIG. 12  shows a further, exemplary embodiment of an auxiliary conveying means for a transverse conveyor comprising conveying compartments. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]     FIGS.  1  to  4  illustrate an exemplary embodiment of the method according to the invention on the basis of a very schematically depicted embodiment of the device according to the invention. The illustrated method is a stream conversion from transverse conveyance to parallel conveyance. The illustrated device comprises a transverse conveyor  1  as supplying conveyor with a direction FQ of transverse conveyance. The transverse conveyor  1  comprises a row of conveying compartments  11  having lateral outlets  13  and being aligned transverse to the direction FQ of transverse conveyance. The device further comprises a parallel conveyor  2  as removing conveyor, having a direction FP of parallel conveyance and being, for example, a stationary pair of band conveyors with a stationary entrance  21  or a simple conveyor belt. Between the transverse conveyor  1  and the parallel conveyor  2  a stationary alignment means  3  is oriented towards the entrance  21  of the parallel conveyor  2 . The alignment means  3  comprises two alignment rollers  31  and  32  of the form already described further above. An auxiliary conveying means (not shown) is assigned to each compartment  11  of the transverse conveyor  1 , for example, a slider whose effect on the articles within the compartments  11  is illustrated by arrows  12 .  
         [0021]     FIGS.  1  to  4  show the device, for example, from above, in such a manner, that the direction FQ of transverse conveyance and the direction FP of parallel conveyance are situated in a horizontal plane and encompass an angle of 90°. If the device according to the invention is oriented in this manner, the conveying compartments  11  of the transverse conveyor may be open on top and on both sides, in particular if the handled articles are relatively heavy and are held in the compartments by gravity. The auxiliary conveying means may comprise one slider in each one of the compartments.  
         [0022]     The mentioned device orientation, however, is not a prerequisite for the method in accordance with the invention. FIGS.  1  to  4 , for example, may also be understood as side views, wherein the direction FQ of transverse conveyance runs vertically and the direction FP of parallel conveyance runs horizontally. In this case, the sides of the conveying compartments  11  directed towards the viewer may need to be equipped with suitable means for keeping the articles in the compartments. It is also not a prerequisite for the method according to the invention, that the angle between the direction FQ of transverse conveyance and the direction FP of parallel conveyance is a right angle. If this angle should differ from 90° the compartments  11  need to be arranged relative to the direction of transverse conveyance such that the conveying direction of the auxiliary conveying means is still parallel to the direction of parallel conveyance.  
         [0023]     FIGS.  1  to  4  illustrate the stream conversion according to the invention essentially on the basis of the transfer of article  5 , which is supplied in the conveying compartment  11 . 1  of the transverse conveyor and is delivered to the parallel conveyor by the alignment means  3 .  
         [0024]     In  FIG. 1 , the conveying compartment  11 . 1  containing article  5  is approaching alignment with the entrance  21  of the parallel conveyor  2  and an edge  5 . 1  of article  5  which is the leading edge in the direction FP of parallel conveyance has left the conveying compartment  11 . 1  and, driven by the auxiliary conveying means is already moving into the action range of the alignment means  3 . The accelerating effect of the auxiliary conveying means is visible from the positions of the articles in compartments  11 . 2  to  11 . 4  upstream of compartment  11 . 1 .  
         [0025]      FIG. 2  illustrates the moment, in which outlet  13  of compartment  11 . 1  is precisely aligned to the entrance  21  of the parallel conveyor. At this moment the article has a speed corresponding to the speed of parallel conveyance and the alignment means starts to act on article  5  by gripping it in a clamping manner between the leading ends of the roller zones of constant maximum radius. From this moment, the leading edge of article  5  is precisely aligned to the entrance  21  of the parallel conveyor  2  and is guided into it by alignment means  3 . After this moment, the trailing zone of article  5  is bent by the relative movement of compartment  11 . 1  and alignment means  3 .  
         [0026]      FIG. 3  shows article  5  at a moment, at which its leading edge  5 . 1  is already held gripped in the parallel conveyor  2 , at which the effect of the alignment means  3  on the article  5  has ended but at which article  5  is still bent, namely between the entrance  21  of parallel conveyor  2  and the outlet  13  of compartment  11 . 1 .  
         [0027]      FIG. 4  finally illustrates how article  5  disappears in to entrance  21  of the parallel conveyor  2  and how a further article supplied in the next compartment  11 . 2  is moved in to the action range of the alignment means  3  by the auxiliary conveying means.  
         [0028]     From FIGS.  1  to  4  it is evident, that it is readily possible to supply two or more than two parallel conveyors with articles using one only transverse conveyor  1 . For such purpose, the entrances of the parallel conveyors  2  have to be aligned to one another in parallel, for example at a distance, which corresponds to a whole multiple of the distance between compartments. The auxiliary conveying means of groups of compartments  11  are then controlled in synchronism, every compartment of a group being assigned to one of the parallel conveyors.  
         [0029]     FIGS.  5  to  8  illustrate a stream conversion from parallel conveyance to transverse conveyance, using substantially the same device and the same method as shown in FIGS.  1  to  4 . The conveying directions FQ and FP and therewith the conveying direction of the not shown auxiliary conveying means (arrows  12 ) point in opposite directions compared with FIGS.  1  to  4  and the alignment rollers  31  and  32  rotate in the opposite direction. The auxiliary conveying means are e.g. designed as grippers being movable within the compartments  11  and gripping the articles by their inner edge (see also  FIG. 12 ). The alignment means  3  is aligned to the entrance  13 ′ of the conveying compartment  11 . 1 , by which the article currently to be transferred is to be taken over, i.e., it is, at least during its acting on article  5 , conveyed together with the compartment  11 . 1  in the direction of transverse conveyance.  
         [0030]      FIG. 5  shows the emergence of the leading edge  5 . 1  of article  5  from the outlet  21 ′ of the parallel conveyor  2  and  FIG. 6  shows the beginning of the action on the leading zone of article  5  by the alignment means  3 , at the moment, in which the entrance  13 ′ of the transverse conveyor  1  and together with it the alignment means  3  is aligned to outlet  21 ′ of parallel conveyor  2 .  FIG. 7  shows the article  5  bent between the outlet  21 ′ of parallel conveyor  2  and the entrance  13 ′ of compartment  11 . 1  after the end of action by the alignment means  3 .  FIG. 8  illustrates the last part of the pulling-in of article  5  in to the compartment  11 . 1  and the emergence of a next article from the outlet  21 ′ of parallel conveyor  2 .  
         [0031]     In the same manner as described further above for the method and the device according to the FIGS.  1  to  4 , it is possible with the method and the device in accordance with FIGS.  5  to  8  also to provide more than one parallel conveyor.  
         [0032]      FIG. 9  depicts an installation comprising a device  30  in accordance with the invention, such as is illustrated, for example, in FIGS.  1  to  4 . The installation serves for producing in a continuous manner (e.g., by collating) stack-shaped groups of partial products and for glue-binding the partial products of every stack. The installation is illustrated in  FIG. 9  as a schematic view from above and in  FIG. 10  as a three-dimensional partial view.  
         [0033]     The installation comprises a collating stretch  10  for producing a stream of stack-shaped groups, the collating stretch comprising a plurality of feed points  20  arranged one after another, wherein at each feed point one partial product is added to each stack. The product edges to be bound are the leading edges and within every stack they are already aligned to one another as accurately as possible.  
         [0034]     The stack-shaped groups being supplied by the collating stretch, are positioned in the compartments  11  of the transverse conveyor  1  of the device according to the invention in a per se known manner, by e.g. being pushed from a conveyor belt into the compartments  11 , which being deviated have an approximately horizontal position or a position being slightly declining towards the inside. The stack-like groups may also be introduced from above into the compartments being conveyed essentially horizontally. In the compartments the stack edges to be bound are facing towards the inside, i.e. downwards. From the compartments  11 , the stack-shaped groups are transferred to the parallel conveyor  2  in the manner described in conjunction with FIGS.  1  to  4 , to be conveyed in to the glue-binding machine  40  and having an orientation suitable for glue-binding (edge to be bound facing downwards and being aligned in conveying direction).  
         [0035]     During conveyance in the compartments  11 , alignment of the part product edges to be bound may be improved by vibrating the compartments or the part products may be laterally aligned in any known manner. Equally during conveyance in the compartments—before they reach the entrance of the parallel conveyor—stack thickness may be measured and auxiliary conveying means in compartments containing too thin or too thick and therefore faulty stacks may not be activated such preventing faulty stacks from being conveyed in to the binding machine but being conveyed on and being e.g. during the next deviation of the conveying compartments  11  to be dropped from the compartment.  
         [0036]      FIG. 10  is a three-dimensional illustration of the one part of the installation according to  FIG. 9 , which comprises device  30  according to the invention. Same elements are designated with same reference numbers as in previous Figs. From  FIG. 10  it is evident, that the transverse conveyor  1  is designed as a circulating system with two deflection rollers. The compartments  11  protruding in radial direction, for example, are attached to two chains circulating in parallel, wherein the chains run over the deflection rollers.  
         [0037]     For stacks having a binding edge with a length of 425 mm, as is the case for magazines, and for a compartment spacing in the transverse conveyor 1 of 8 cm, for achieving a capacity of 15,000 copies per hour, a speed of transverse conveyance of 0.34 m/s and a speed of parallel conveyance of 1.7 m/s are required. For a capacity of 18,000 copies per hours, the speeds are correspondingly 0.42 and 2.13 m/s.  
         [0038]     It is particularly advantageous, if for producing the stack-shaped groups the method described in the patent application WO-03/053831 is used, i.e. the groups are produced not by collating, but rather by guiding imbricated streams of different part products to be superimposed. The part products in all imbricated streams are arranged in such a manner, that leading edges of the part products of each group are aligned to one another. From the leading end of the superimposed imbricated streams the groups are separated in succession by gripping the aligned part product edges and are advantageously directly transferred in to compartments  11  of the transverse conveyor  1 .  
         [0039]      FIG. 11  shows in more detail an exemplary embodiment of conveying compartments  11  for a transverse conveyor  1  as shown in the preceding Figs. Each conveying compartment  11  comprises an upstream wall  51  being rigidly connected to a compartment floor  50  and a downstream wall  52  being pivotally supported in the compartment floor. The downstream wall  52  is held in a closed position by a not illustrated resetting means and it is brought into an open position controlled, for example, by a cam  53 , on which a control roller  54  arranged at the lower end of the down-stream wall  52  rolls. The compartments are arranged on a circulating conveying organ, e.g., chains (dot-dash line  55 ), in such a manner that they follow one behind the other as closely as possible when being conveyed along a straight path and that they are capable of being opened sufficiently for introduction of the flat articles  5  or of the stack-shaped groups of part products in the area of the deflection wheel  56 .  
         [0040]      FIG. 11  shows an auxiliary conveying means in the form of a slider  60  being provided in each one of the compartments  11 . The slider  60  protrudes in to the compartment  11  through a corresponding slit in the upstream wall  51  and is supported outside of the upstream wall  51  by a longitudinal guide system  61 . The slider movement parallel to the axis of the deflection wheel  56  is controlled by a cam (not shown), on which control rollers  62  installed on the slider roll.  
         [0041]     For an adjustment of the compartments  11  to the thickness of the articles  5  or the stacks to be processed, it is advantageous to design the pivoting support of the downstream walls  52  to be displaceable in such a manner, that the width of the compartment floor  50  becomes adjustable.  
         [0042]     It is also possible to provide an external slider or an arrangement of a plurality of external sliders instead of the sliders according to  FIG. 11  which are arranged within every compartment  11  and to move the external slider into the compartments in a direction oblique to the direction of transverse conveyance. Such auxiliary conveying means is, for example, described in the publication U.S. Pat. No. 1,760,030 mentioned further above.  
         [0043]      FIG. 12  illustrates a further, exemplary embodiment of an auxiliary conveying means for a conveying compartment  11  of a transverse conveyor in accordance with the invention. The conveying compartment  11  which has no upstream wall is viewed perpendicular to the direction of transverse conveyance. The auxiliary conveying means comprises two jaw-like clamping parts  70  (one of them visible) being mounted on a slide  71  and being movable against each other and away from each other. Slide  71  is arranged near the compartment floor  50  and is displaceable transverse to the direction of transverse conveyance. The slide movement is controlled, for example, by a cam  73 , on which a control roller  74  arranged on a slide part protruding from the compartment  11  rolls.