Abstract:
A crossing between two transport lines is configured for the horizontal transport of planar articles, preferably in the form of an imbricated stream, of which one transport line is led away at a crossing over the other transport line. Controllable means for transferring the transported articles from one of the transport lines to the other are provided, which, in a first setting, freely admit the transport of the articles on one of the transport lines and, in a second setting, divert the transported articles from one of the transport lines to the other. A transfer apparatus may include a flexible diversion line, which describes a space curve and which with a movable free end, in the first setting, maintains a distance to one of the transport lines and, in the second setting, engages with the free end in one of the transport lines to effect a diversion.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     Swiss Patent Reference 00671/11, filed 14 Apr. 2011, the priority document corresponding to this invention, and its teachings are incorporated, by reference, into this specification. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to the field of transport technology, as is used, in particular, within print finishing. It relates to a crossing between two transport lines, according to the preamble to claim  1 . 
     2. Discussion of Related Art 
     In print finishing, also know as print further processing, but not just in this sphere, planar articles, for example folded printed sheets, newspapers, brochures, flyers or the like, are frequently transported in compressed form as an imbricated stream between the various treatment and/or storage stations. It is here often necessary to divert imbricated streams from one transport line to another, intersecting transport line, this diversion being intended to be realized by switchable means. In a first setting, the articles are forwarded on one transport line without further obstacle. In a switchable second setting, the imbricated stream is diverted from one transport line to the intersecting other transport line. The imbricated stream formation as such is here intended to remain as far as possible unchanged. 
     Printed publication DE 33 02 935 discloses an apparatus for turning partial imbricated streams of given length, consisting of printed sheets or the like, about their vertical centre axis, in which printed sheets in the form of an imbricated stream are directed via a right-angled diverter to a points switch, and from this onto a winding station belt. The printed sheets are spooled with a winding tape onto a core to form a reel and are temporarily stored in this form. If the printed sheets are to be fed to the finishing facility, then the winding tape is unrolled from the reel and rolled back on from a tape supply roll. As the winding tape is unrolled from the reel, a points switch is pivoted into a lower position, whereby the printed sheets make their way onto a lower, right-angled diverter, and from this onto a part of a conveying line (see  FIGS. 1 and 2  of this publication). The diversion between the individual lines is here realized by fixed 90° deflectors, the free ends of which are arranged one above the other and can be freely selected by a points switch. 
     Printed publication DE 33 04 219 discloses an apparatus for stacking printed sheets, having a hub rotatably mounted in a machine stand, having a tape which is led up to the hub along a predefined path and can be spooled onto or Unspooled from this, a first transfer point being provided on the path of the tape. The tape is guided over a plurality of diverting rollers and can selectively be spooled on one of two hubs and forms on its path a first transfer point and a second transfer point. A points switch arrangement connects, on the one hand, the second transfer point to a feeder conveying line and to the first transfer point. It further connects the first transfer point to an evacuation line. The points switch arrangement has a fixedly mounted conveyor belt, which can be driven in two directions, as well as two parallel conveyor belts, whose ends facing one conveyor belt can be swung up and down. If, on the feeder conveyor line, a multiplicity of printed sheets which are joined together into a partial imbricated stream are advanced and the printed sheets are ejected from there onto one conveyor belt, then these printed sheets, once again in the form of a partial imbricated stream, are transferred from the lowered end of the conveyor belt onto the other conveyor belt, and from there onto a further belt (see  FIGS. 1-3 ). In this case, too, the switchable diversion is effected solely by pivotable switch points. 
     The same also applies to the device for processing print products according to printed publication WO 94/02398. 
     In all cases known from the prior art, actively driven points switches are used to achieve switchability, whereby a more complex drive mechanism and control system is demanded. Moreover, the imbricated stream formation is frequently changed or influenced. 
     SUMMARY OF THE INVENTION 
     One object of the invention is therefore to configure a crossing of the generic type such that these drawbacks are avoided and that, in particular, a simplified switchover is possible. 
     These and other objects are achieved by the features of claim  1 . 
     The invention is based on a crossing between two transport lines configured for the horizontal transport of planar articles, in particular print products, preferably in the form of an imbricated stream, of which one transport line is led away over the other transport line at a predefined distance apart and angle, wherein, in the region of the crossing, controllable means for transferring the transported articles from one of the transport lines to the other of the transport lines are provided, which controllable means, in a first setting, freely admit the transport of the articles on one of the transport lines and, in a second setting, divert the transported articles from one of the transport lines to the other. It is characterized in that the transfer means comprise a transfer apparatus having an adaptable diversion line, which describes a space curve and which with a movable free end, in the first setting, maintains a distance to one of the transport lines and, in the second setting, engages with the free end in one of the transport lines to effect a diversion. 
     One embodiment of the invention is distinguished by the fact that the other end of the diversion line is transport-connected to the other of the transport lines. This allows the adjustment mechanism to be simplified further. 
     The mechanism becomes particularly simple if, according to another embodiment, the diversion line has a constant length and, upon movement of the free end of the diversion line, the space curve of the diversion line changes. By movement is here understood, inter alia, a displacement and also a pivoting. 
     A further embodiment of the invention is characterized in that the diversion line has at least one supporting strip which tracks the space curve and on which the articles transported on the diversion line are guided in recumbent arrangement. 
     The supporting strip can consist of various materials, for example a plastic. In particular, the at least one supporting strip can be a metal or sheet-metal strip, which is particularly resistant during operation and, in combination with simultaneously high stability, adapts well to the space curve. 
     For the support of the articles, it is particularly advantageous if two mutually parallel running, spaced-apart supporting strips are provided, and a roller conveyer, tracking the space curve, is arranged between the supporting strips. 
     In particular, for the transport of the articles along the roller conveyor, a driven lower belt resting on the roller conveyor is provided. 
     For the fixing of the articles on the lower belt, an adjacent upper belt, which is passively moved together with the lower belt, is provided. 
     Another embodiment of the invention is distinguished by the fact that in one of the transport lines is provided a swing-out line portion, and that on the movable free end of the diversion line is arranged an actuating means, with which the diversion line, upon engagement in one of the transport lines, pivots the swing-out line portion out of one of the transport lines. 
     Preferably, for the movement of the free end of the diversion line, an adjusting apparatus is provided. 
     The adjusting apparatus advantageously works pneumatically or hydraulically or electrically. 
     Another embodiment is characterized in that the two transport lines intersect at an angle of substantially 90°, and in that the diversion line describes a space curve, which effects a diversion of substantially 90°, with simultaneous turning of the planar articles. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention shall be described in greater detail below with reference to illustrative embodiments in association with the drawing, wherein: 
         FIG. 1  shows in top view from above the layout of a crossing according to an illustrative embodiment of the invention, wherein the diversion is indicated by a dashed double arrow; 
         FIG. 2  shows in two sub- FIGS. 2(   a ) and  2 ( b ) the crossing from  FIG. 1  with disconnected diversion (a) and with connected diversion (b); 
         FIG. 3  shows in a perspective side view an illustrative embodiment for a dual transfer apparatus, as is used in a (double) crossing according to  FIG. 2 ; and 
         FIG. 4  shows the illustrative embodiment from  FIG. 3  in another perspective side view. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     In  FIG. 1 , the (heavily simplified) layout of a crossing according to an illustrative embodiment of the invention is represented in top view from above. The crossing  10  consists in this case of two transport lines  11  and  12 , which intersect at a right angle of α=90° and on which the planar articles  14 , here in the form of an imbricated stream  13 , can be transported in the longitudinal direction of the line. In principle, the transport on the transport lines  11 ,  12  can be realized in both directions. In the present example, the transport line  12  is configured as a solid continuous line, whilst the transport line  11  which leads away over it at a distance apart comprises a plurality of line portions  11   a - c . As becomes clear from  FIG. 2 , the middle line portion  11   b  is configured as a swing-out portion. 
     Between the lower transport line  12  and the intersecting transport line  11  lying above it at a distance apart d is arranged a transfer apparatus  15 , which in  FIG. 1  is indicated merely by a dashed double arrow, yet in the side view of  FIG. 2  can be seen in schematic representation. The transfer apparatus  15  comprises a diversion line  25 , which tracks an intrinsically distorted space curve, so that the articles  14  transported on the diversion line  25  are diverted by 90° in the plane of the intersecting transport lines  11 ,  12  and, at the same time, turned. In addition, the articles  14  are raised or lowered in height by the distance d, depending on the transport direction. An intrinsically distorted space curve of this kind has the particular advantage of being adaptable. 
     This adaptability of the diversion line  25  is of particular importance for the present invention, since it enables a particularly simple design of the switchable transfer apparatus  15 . This can be illustrated in a simple manner with reference to  FIG. 2 : According to  FIG. 2   a , the diversion line  25  of the transfer apparatus  15  is arranged in such a way beneath the middle line portion  11   b  of the above-situated transport line  11  that, when the curved diversion line  25  is stretched (transition from  FIG. 2   a  to  FIG. 2   b ), the diversion line  25  presses with its free end or head  16 , via an actuating means  17 , from below against the pivotable or hinged middle line portion  11   b  and swings it out upwards ( FIG. 2   b ). At the same time, the diversion line  25  connects with the head  16  to the line portion  11   a , such that articles  14  which are advanced on this line portion can be transferred directly to diversion line  25 , or (in the case of the reverse transport direction) articles  14  led up via the diversion line  25  can be forwarded directly to the line portion  11   a . The swing-out of the middle line portion  11   b  can be realized—as described above—passively. It is also conceivable, however, to provide a dedicated drive mechanism for the swing-out. 
     If the engagement of the transfer apparatus  15  in the transport line  11  is to be terminated, the head  16  is relowered, whereby the middle line portion  11   b  falls back into the non-swung-out position of  FIG. 2   a  and recloses and opens up the transport line  11 . In this switching operation, the other end of the transfer apparatus  15  or diversion line  25  remains fixedly connected to the transport line  12 . In principle, however, it is conceivable for the transfer apparatus  15 . to  be configured on this side also such that it can be switched over analogously. Furthermore, in preferred embodiments it is provided (see also  FIG. 3 ) to configure the transfer apparatus  15  such that it is displaceable along the transport line  12  in order with the same transfer apparatus  15  to reach other crossings of the transport line  12  or more than one crossing with transport lines running transversely across it for the purpose of diversion. However, it is also conceivable to provide on the transport line  12  two oppositely diverting transfer apparatuses of the described type, which are selectively driven under the crossing  10  in order to divert an imbricated stream  13  arriving on the transport line  11  to the left or right onto the transport line  12 . 
     In  FIG. 3 , two parallel-working transfer apparatuses  15   a  and  15   b  are arranged next to each other, which transfer apparatuses are respectively displaceable on an associated transport line  18   a  and  18   b . On the transport lines  18   a,b  are provided conveyor belts  19   a,b , which circulate in the longitudinal direction of the line and with which the transport of the articles  14  from and to the transfer apparatuses  15   a,b  is realized. 
     In the transfer apparatuses  15   a,b  is respectively arranged a roller conveyor  21  having rollers which are placed one behind the other along a predefined space curve. Over the rollers of the roller conveyor runs a motor-driven lower belt  22 , on which the articles rest in imbricated stream formation. From above, an upper belt  23  nestles in the space curve against the lower belt  22 , so that the imbricated stream of the articles is held and transported between the two belts  22  and  23 . The upper belt  23  is here not itself driven, but run along by frictional engagement. 
     On both sides of the roller conveyor  21  are arranged wide supporting strips  20   a, b , which run parallel to the roller conveyor  21  through the predefined space curve. The supporting strips  20   a,b  can be configured as plastics strips, yet preferably consist of a bendable steel plate. This has the benefit, inter alia, that electrostatic charges are largely avoided. The shape of the space curve of the diversion line  25  is here materially jointly determined by the deformation behaviour of the supporting strips  20   a,b . As the name says, the supporting strips  20   a,b  support the planar articles held between the belts  22  and  23 . 
     On the head  16  of the transfer apparatuses  15   a,b , which head, upon switchover, is moved in the vertical direction, is arranged an actuating means  17 , which comprises an axle  26  mounted in an upwardly protruding frame. The upper belt  23  is guided divertingly about this axle  26  and forms together with the lower belt  22  an inlet for the articles which are to be accepted. 
     The head  16  with the actuating means  17  can be moved vertically by a hydraulically or pneumatically (or even electrically) operated adjusting apparatus  24  (operating cylinder), so that the actuating means  17  engages with or disengages from the middle line portion  11   b . As can be seen in  FIG. 4 , the roller conveyor  21  has in the region of the head  16  a pivotable portion  27 , which, by means of the adjusting apparatus  24 , can be pivoted upwards or downwards about a pivot axis  28  and hereupon moves the actuating means  17 . 
     When the portion  27  or the actuating means  17  is pivoted, the supporting strips  20   a,b  are geometrically deformed. By virtue of their elastic bendability, these can compensate the difference in height through which the head  16  passes in the lower and upper position. It is a particular advantage that, given point suspension of the supporting strips  20   a,b , the necessary geometric deformation can be equalized over the whole of the, or in any event over appreciable surface areas of the supporting strips  20   a,b . Self-evidently, in this operation, the roller conveyor  21  and the belts  22  and  23  are moved jointly in accordance with the height adjustment. Because of their flexibility, their three-dimensional compensation motion can be structurally achieved with known means. 
     In the embodiments which are shown here, the transport lines  11  and  12  are of flat and rectilinear configuration. In particular applications however, it may also be advantageous to arrange the transport lines, or the line portions  11   a - c  thereof, along spatial curves (for example in a flat curve or with a line which overcomes a plane offset). In such arrangements, the lead-in of the head  16  shall be chosen such that a homogeneous lead-in region is obtained. Of course, the transport line  12  can also, if required, have a plurality of line sections. 
     In preferred embodiments, furthermore, the lead-in region for the planar articles in the region of the head  16  can be realized, instead of in a hinged line portion, also in a closable opening between the line portions  11   a  and  11   b . In this case, a gap exists between the ends of the two line portions  11   a,b , which gap can preferably be bridged by a displaceable or movable intermediate element (not depicted). When the head  16  is raised, the intermediate element can be pushed away, for instance by a suitable lever system. This solution is advantageous when the raising of the line portion  11   b  (cf.  FIG. 2 ) can cause collisions with above-situated components. Here too, the clearance at the lead-in point is realized only by a drive which actuates the head  16 . 
     The diversion line  25 , as shown in  FIGS. 2   a  and  2   b , has the aforementioned distorted space curve. Within the scope of the inventive concept, it is possible to construct this space curve in various curve shapes, e.g. in the style of a loop, in order to guide the products from above onto the line portion  11  or away from this. 
     The products can be transported in a known manner in the form of an imbricated stream, but also in isolation or in multilayered arrangement. Furthermore, the angle which the transport lines  11  and  12  form with one another can be realized, apart from in the shown right angle, also in other arrangements, for instance with a 60° angular position. 
     If, with the described arrangement, the articles are transported and transferred in the form of imbricated streams, these can also be used, in suitable operation, either to condense the imbricated stream by shortening the distance between successive articles or extend it by lengthening this same distance. Such a change in imbricated stream density is achieved by virtue of the fact that the transport speed of the imbricated stream is chosen differently before and after the transfer between two lines: For stretching of the imbricated stream, the post-transfer transport speed is higher, for compression it is lower. By turning the imbricated stream in the transfer apparatus  15   a,b , it is here possible to ensure that the foremost article in the imbricated stream always comes to lie at the very bottom. 
     Typically, the invention makes use of a matrix-like 1:n or a m:n arrangement of the transport lines (i.e. for instance 1 transport line  11  crossed with n transport lines  12 , or m transport lines  11  crossed with n transport lines  12 ).