Abstract:
The invention relates to a device ( 1 ) and a method for conveying flexible, two-dimensional objects ( 100, 100 ), in particular printed products, with a plurality of conveyor elements ( 10 ) which are movable in a conveyor direction (F) by a conveyor member ( 20 ) drivable along a closed revolving path (U) and which are capable of receiving and conveying at least one object ( 100, 100′ ). A stabilisation device ( 30 ) with at least one stabilisation member ( 32, 33, 36 ) is present for stabilising the objects ( 100, 100′ ), in particular in regions (B) of the revolving path (U), in which large accelerations occur. The stabilisation device ( 30 ) forms a compliant stabilisation line ( 34′ ) or stabilisation surface ( 34 ) and presses the objects ( 100, 100′ ) against the conveyor element ( 10 ) at least in a part of the revolving path. By way of this, one prevents the objects from being displaced relative to the conveyor element ( 10 ), which may lead to problems with the further processing.

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
       [0001]    The invention lies in the field of conveyor technology and relates to a device as well as to a method for conveying and simultaneous stabilisation of flexible, two-dimensional objects, in particular printed products. 
         [0002]    Conveyor systems with conveyor elements, e.g. grippers or pockets, which are moved along a closed revolving path, necessarily have regions in which the orientation of the revolving path and thus the momentary conveyor direction changes. If flexible objects are received and conveyed by the conveyor elements, then in curved sections of the revolving path, it may occur that held products are upset to the front or rear due to gravity and/or accelerations in the conveyor direction. This is disadvantageous above all in those cases, in which the objects are to be fed by the conveyor elements to a further processing step, which requires a defined object position in or relative to the conveyor element. 
         [0003]    The outlined problem may occur, for example, in a device as is described in the CH patent application No. 1724/08 which has no prior application. This device serves for collecting printed products in grippers along a part of the revolving path, which acts as a collection path. The grippers have an extended gripper jaw which in particular when collecting (in the opened condition of the gripper) acts as a support surface. If the collection procedure has been carried out in a correct manner, the objects are released to a further-processing station, e.g. inserted into folded printed products. This release, as a rule, is effected at a location which lies above the collection path. If an error has been ascertained, in particular the absence of a product, the objects are not released, but are conveyed back to the collection path in a repair run-through, where the missing product may be added. In the dropping part of the revolving path, it may occur that the objects are upset to the front due to gravity and, thus, no longer lie on the support surfaces orientated opposite to the conveyor direction. This however leads to the fact that the repair procedure may no longer be carried out, in particular since missing products may not be correctly applied, if the objects lying therebelow are folded over to the front. 
         [0004]    An undesired positional change of the received objects may also occur with other applications. Sharp curves, however, may often not be avoided for reasons of space (limited space). 
       BRIEF SUMMARY OF THE INVENTION 
       [0005]    It is, therefore, the object of the invention to avoid the disadvantages of the state of the art and to provide a conveyor device and a corresponding conveyor method, with which an undesired positional change of the conveyed objects may be avoided, even with larger accelerations. 
         [0006]    The conveyor device according to the invention serves for conveying flexible, two-dimensional, i.e. flat, objects, in particular printed products. It comprises a plurality of conveyor elements which are movable in a conveyor direction by way of a conveyor member drivable along a closed revolving path, and which are capable of receiving and conveying at least one object. It is particularly the case of grippers which receive the objects and fix them in a clamping manner. The conveyor elements may, however, also be pockets or other receiver compartments, in which objects are held in a non-clamped manner. The conveyor member, for example, is a chain, which is guided in a channel, by way of whose shape the revolving path is also set. According to the invention, at least one stabilisation device with at least one stabilisation member is present, which is capable of acting on the object at least in a part of the revolving path. The stabilisation member forms a compliant, flexible stabilisation surface or stabilisation line for the objects, which preferably runs essentially parallel to the revolving path. Said stabilisation surface or stabilisation line is preferably resilient. It is, thus, not the case of a rigid guide surface, but the stabilisation force on account of its compliance may adapt flexibly to different objects, without the objects jamming or having too much play. The stabilisation member presses the objects against the conveyor element and, thus, realises a defined position relative to the conveyor element. 
         [0007]    Brush strips or co-moved or stationary strips or belts or other elastic elements serve as a stabilisation member. The latter is given the desired shape by way of suitable guide elements or deflection elements as well as, as the case may be, by way of the cooperation with the conveyor elements. The mentioned stabilisation members are mechanically simple. A stabilisation may therefore be realised with little effort and inexpensively, and leads to a significantly reduced rejection. 
         [0008]    The stabilisation member preferably acts on the objects in a part of the revolving path, by way of the path direction changing and therefore by way of forces acting on the objects, which without stabilisation would lead to a position change relative to the conveyor element. Such parts, for example, are regions in which the path directions or path speed changes, the revolving path rises, falls and/or in which the conveyor elements change their orientation with respect to the revolving path, for example because the conveyor member or its guide is twisted (twisted here includes a winding about an axis). The invention also permits the use of an overhanging revolving path, i.e. upside down conveying, without the objects changing their general position to the conveyor element. In particular, the leading edge of the objects is always leading and the trailing edge always trailing. 
         [0009]    In a preferred variant, the conveyor elements comprise a support surface, which is inclined in or opposite to the conveyor direction, so that received objects bear on the support surface due to gravity, with a horizontal conveyor direction. The conveyor elements may thus particularly be applied for collection. The stabilisation members are preferably designed such that they press the objects against the support surface or towards the revolving path of the conveyor elements. The support surface is, therefore, flexible in this direction and preferably co-biased, so that it may exert pressure in the direction of the revolving path of the conveyor elements. This applies at least in the regions, in which forces act on the objects, which without stabilisation would lead to a lifting of the objects from the support surface. Alternatively, the stabilisation members may also be designed such that the stabilisation surface or stabilisation line has a distance to the support surface, so that no pressure is exerted onto the support surface, but an upset of the objects to the front or to the rear is prevented. 
         [0010]    Preferably, the support surface has at least one groove, into which the at least one stabilisation member is capable of engaging. The stabilisation member and support surface thus cooperate in a meshing manner. One may also reliably stabilise objects, which are shorter than the support surface, thus which do not project beyond the edge which is distant to the conveyor member, at this end, on account of this measure. 
         [0011]    The invention may advantageously be applied with the initially mentioned device according to CH patent application No. 1724/08. With this device, for the collection, one does not use pockets, but grippers with an extended or widened gripper jaw, which simultaneously serves as a support surface and collection rest. The extended gripper jaw is preferably designed in a two-part manner, wherein the two gripper jaw parts are pivotable relative to one another, in particular are controlled. 
         [0012]    Instead of a position, in which the held edge is leading, the held edges may also be trailing and the objects stabilised in this position. Moreover, an application with conveyor devices other than gripper conveyors, with which a position change of the objects is to be counteracted, is likewise conceivable. A gripping of the objects by the conveyor units is not absolutely necessary, and the objects for example may also be stabilised in pockets without any clamping function, by which means a clamping function may be done away with. 
         [0013]    Rigid guide elements, e.g. guide rails may be present additionally to the stabilisation device. These for example are arranged in front of the stabilisation device in the conveyor direction, and effect a pre-positioning of the objects. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    Examples of the invention are shown in the drawing and are described hereinafter. In a purely schematic manner, there are shown in: 
           [0015]      FIG. 1  a conveyor device with a stabilisation device, which comprises at least one brush strip; 
           [0016]      FIGS. 2   a - c  a conveyor device with a stabilisation device, which comprises at least one driven round belt; 
           [0017]      FIG. 3  a conveyor device with a stabilisation device, which comprises at least one elastic element; 
           [0018]      FIG. 4  a conveyor device with a stabilisation in an overhanging section of the movement path; 
           [0019]      FIG. 5  a conveyor device with a stabilisation in a twisted section of the movement path. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0020]      FIG. 1  shows a conveyor device  1  with a plurality of conveyor elements  10  and a first variant of a stabilisation device  30 . The conveyor means  1  here is shown merely by way of example. Basically, one may also use differently shaped conveyor elements  10 . 
         [0021]    The conveyor device  1  comprises a plurality of conveyor elements  10 , which here are designed as grippers  12  with a first gripper jaw  13  and with a second gripper jaw  14 . The first and second gripper jaw  13 ,  14  are pivotable about a pivot axis S between an open position and a clamping position. The grippers  12  are fastened on a conveyor member  20  in the form of a chain with several chain links  21 . The chain  20  is moved in a guide member  22 , here a channel. The revolving path U of the chain  20  and by way of this, also the path of the grippers  12 , is defined by way of the shape of the channel  22 . The trailing first gripper jaw  13  of the gripper  12  here consist of two gripper jaw parts  13   a ,  13   b  which are pivotably connected to one another via a joint  17 . The pivot position is controlled via a control element  18 . The control element  18  here is present in the form of a lever, which is pivotably connected to the trailing chain link  21 . The pivot position changes depending on the shape of the revolving path. 
         [0022]    The two gripper jaw parts  13   a ,  13   b  define a support surface  15  for the received objects  100 . The objects in a region of the revolving path, in which the grippers  12  are open and in which the support surface  15  points upwards or obliquely to the front or rear, may be introduced into the gripper  12  or applied onto the support surface  15 . Thereby, they are aligned on an abutment  16 , which is formed by the base of the gripper jaw. Objects  100  may be fed at several stations and, thus, may be collected in the open gripper  12 . The gripper  12  is subsequently closed. The objects  100  are fixed at their leading edge  100   a  and may, thus, be conveyed in a clamped manner along an infinitely shaped path U. This is described in the already motioned application CH 1724/2008. The two-part support surface  15  permits a good leading of the objects  100  with their release. This is described in the application CH 00553/2009 which has no prior publication. 
         [0023]    The stabilisation device  30  according to the invention, acts on the objects  100  or the conveyor elements  10  in a region B of the revolving path U, in which this revolving path U drops from a first level N 1  to a second level N 2 . The conveyor elements  100  here have a movement component in the downwards direction (thus towards the ground). Without a stabilisation device  30 , the objects  100  which are only fixed at their leading edge  100   a , under certain circumstances would release from the support surface  15 , so that their trailing edges  100   b  are upset to the front or to the rear. With the transition into a section of the revolving path with a reduced curvature or horizontal alignment, this folded-over position under certain circumstances is retained. The stabilisation device  30  counteracts this folding-over by way of it pressing the objects  100  gently and with a low force against the support surface  15  in the sloping region B. For this, according to the invention, it forms a compliant stabilisation surface or stabilisation line. 
         [0024]    Here, the stabilisation device  30  comprises at least one stabilisation member in the form of a brush strip  32 . The brush strip  32  is fastened on a holder  31 , which has somewhat the shape of the revolving path U in the region B, thus runs roughly parallel to the revolving path U. The bristles of the brush strip  32  are aligned roughly perpendicularly to the holder  31  or to the revolving path U. In the unloaded condition (i.e. without the presence of conveyor elements  10 ) they therefore define a bent stabilisation surface  34 , running parallel to the revolving path U and having a distance from this, which is smaller than the minimal distance of the non-held object edge  100   b  to the revolving path U. On moving the conveyor elements  10  through the region B, the bristles are deformed and brush along the support surface  15 . By way of this, the objects  100  are pressed softly against the support surface  15  and thus are well positioned. The stabilisation surface  34  which is formed by the envelope of the brush strip  32 , is elastically deformed by way of this and obtains a type of wave shape or saw-tooth shape. The pressure on the objects  100  is so small, that these are not compromised, and also no jamming occurs. 
         [0025]    Preferably, the support surface  15  in the second gripper jaw part  13   b  has at least one groove  19 , into which the stabilisation member may engage. This is shown in  FIG. 2   b  with regard to one variant of the stabilisation device  30 . The groove  19  permits one to also stabilise objects  100  which are shorter than the support surface  15 . 
         [0026]    Preferably two parallel brush strips  32  are present, which engage into two grooves  19 . Instead of brushes of natural material or plastic, one may also use surfaced, i.e. flat, flexible rubber elements. 
         [0027]      FIGS. 2   a - c  show a conveyor device  1  as in  FIG. 1 , with a further embodiment of the stabilisation device  30 . This here comprises at least one stabilisation member in the form of a round belt  33 . Preferably, two parallel round belts  33  are present. The round belts  33  are guided via deflection rollers  35 , such that they may act on the conveyor elements  10  or the objects  100  held therein, in a part region T of their path U′ (T thus corresponds to the active section of the belt  33 ). This region T in the present example would be almost straight in the unloaded condition (without the presence of conveyor elements  10 ). With more or differently arranged deflection rollers  35 , one may realise other path curves U′. The round belt  33 , by way of the conveyor elements  10  which push the round belt  33  away from the revolving path U, is deformed such that the region T is roughly parallel to the revolving path U. The round belt  33  therefore in the region T defines a compliant stabilisation line  34 ′. A stabilisation surface  34  is set (see  FIG. 2   b ) if two parallel round belts  33  are present. The round belt  33  exerts a slight pressure directed towards the channel  22 , but is compliant (direction of the double arrow in  FIG. 2   b ), and may thus adapt to different object formats. 
         [0028]    The round belt  33  is preferably driven by way of a drive which is not represented in more detail here, with the same or with a reduced speed with regard to the conveyor elements  10 . 
         [0029]      FIGS. 2   b+c  show the stabilisation of the objects  100  with a different format. The object  100  has a length which is so large that its non-held edge  100   b  projects beyond the support surface  15 . The object  100 ′ has a smaller length, so that its non-held edge  100   b ′ does not project beyond the support surface  15 . The support surface  15  has two parallel grooves  19 . The round belts  33  are guided such that they may run in the grooves  19  and are compliant in the direction of the grooves  19 . This is indicated in  FIG. 2  by a double arrow. With a smaller format, the round belts  33  run in the grooves  19  and act on the free edge  100   b ′ (see also lateral view  FIG. 2   c ). With a larger format, the distance of the round belt  33  to the revolving path U is increased, and the round belts  33  run outside the conveyor surface  15 . In any case, the free edges  100   b ,  100   b ′ are reliably supported. The same effect occurs, when with regard to the stabilisation members, it is the case of other means, which may engage into the grooves, e.g. the brushes or brush strips shown in  FIG. 1 . 
         [0030]      FIG. 3  shows an example with a stabilisation device  30 , which as a stabilisation member comprises a stationary, elastically deformable element  36 . The element  36 , for example, is a leaf spring whose shape is adapted to the shape of the revolving path in the region B and which is arranged parallel to this. It may be mounted on one side. It may also be the case of a compliant steel wire, a rubber band or a spiral spring with a very narrow winding distance. In this case, the element  36  is preferably mounted on two sides, such that it spans the region B. Preferably, as with the above mentioned examples, two elements are present  36  which may engage into corresponding grooves  19  in the conveyor elements  10 . 
         [0031]      FIG. 4  shows an example, as to how the stabilisation device  30  may be applied with a conveyor path, with which the objects, for example, are conveyed upside down in regions. The revolving path U has a region bent in an S-shaped manner. The stabilisation device  30 , which here may be realised by way of each of the variants shown in  FIG. 1-3  (the brush strips according to  FIG. 1  are shown only by way of example), extends over the complete part region B by way of the inclination of the revolving path exceeding a predefined value and by way of conveying upside down. 
         [0032]    The conveying upside down, without the objects changing their position relative to the conveyor element  10  is only possible at all due to the stabilisation device. By way of this, it is possible to realise the conveyor path in a relatively restricted space, for example the overcoming of the height difference from the level N 1  to level N 2 , without enlarging the installation in the horizontal direction. 
         [0033]      FIG. 5  shows a further example, with which the revolving path U has a section U″ which is twisted (twisted here includes a winding about an axis). The conveyor elements  10  here undergo a rotation about 90° from a position, in which the pivot axis S of the gripper  12  lies perpendicular to the drawing plan, into a position, in which the pivot axis S lies in the plane of the drawing. Additionally, the revolving path U drops greatly in this section U″. The stabilisation device  30  is arranged such that its stabilisation surface  34  follows the course and the orientation of the revolving path U. The stabilisation surface is therefore firstly arranged perpendicular to the plane of the drawing, and in the section U″ is rotated into a position parallel to the plane of the drawing. 
         [0034]    Such twisted sections are only possible at all due to the stabilisation, since the accelerations which occur thereby are compensated by the stabilisation device  30 , such that the object  100  does not detach from the support surface  15 . It is possible by way of such twisted sections to design the revolving path and adjacent processing stations with greater flexibility with regard to space.