Abstract:
A method and a device for the conveyance of planar products ( 10, 10′, 20, 20 ′), in particular printed products, are provided wherein a product group ( 100 ) composed of at least two products ( 10, 10′, 20, 20 ′) is gripped by a gripper ( 42 ) in the area of a product edge ( 12, 12′, 22, 22 ′) and conveyed in a direction of conveyance (F 2 ). At least one of the products ( 10, 10′, 20, 20 ′) is displaced relative to the other product or products ( 10, 10′, 20, 20 ′) in the product group ( 100 ) in a direction of displacement (A) defined by the gripped product edge ( 12, 12′, 22, 22 ′), such that in each case a projection ( 14, 24 ) is formed in the direction of displacement (A). Thus a first projection ( 14 ) is associated with at least one displaced product ( 10, 10′, 20, 20 ′) and a second projection ( 24 ) is associated with the remaining product or products ( 10, 10′, 20, 20 ′) of the product group ( 100 ). Thus, it is easy to increase the carrying capacity of a gripper conveyor and, when applicable, to easily separate the products that are gripped in groups.

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention pertains to the field of conveyance technology for planar products, in particular to the field of handling printed products. 
     The capacity of rotary printing presses has steadily increased in recent years. At present, an output on the order of about 170,000 copies per hour is possible. This places higher demands on the post-processing operations. In order to convey the products to a post-processing operation, for example the insertion of supplements, addressing, etc., it is necessary to convey the products in an imbricated stream by means of a conveyor belt, and/or to transfer them singly to a gripping device and thereby transport them further. Intermediary steps such as buffering in a storage winding roll or the arrangement of the product into stacks or piles can be interposed. 
     At present, gripper conveyors still have difficulty achieving the conveying rates described above. Yet, it is often desired to convey the product with a gripper conveyor, as the gripper conveyor makes possible precise, defined handling and is more appropriate than a conveyor belt for conveying products at higher speeds and over longer distances. A gripper conveyor also makes possible the individual selection of products, for example for the introduction of supplementary materials, or the application of address labels, or also in order to alter the formation of an original imbricated formation. The latter is above all of interest if an existing imbricated formation does not have the appropriate configuration for the post-processing operations, e.g. with the leading edges underneath rather than on top of a trailing product, folded edges trailing rather than leading. 
     It is disclosed in e.g. DE-A 2417614 or CH 634 530 that rotary printing presses deliver folded products in pairs in an imbricated stream with folded edges leading, wherein in each case a product of a pair of products is arranged within the other product, however in each case with a lateral displacement with respect to this other product in the direction of their respective folded edges. The pairs are subsequently pulled apart from each other in the direction of displacement, being gripped in each case in the area of the product which projects laterally past the respective other product (hereafter referred to as the projection). This creates two imbricated streams, each with half of the original conveying rate. In general, these can without difficulty be further conveyed by means of a conventional gripper conveyor. 
     It is disclosed in EP-A 0 936 169 how a simple imbricated stream may be converted, by means of a deflection transverse to its direction of conveyance, into an imbricated stream in which in each case two products lie side by side and overlap. In each case two conveyed products which originally are situated one in front of the other come to be situated side by side in the outgoing imbricated stream, wherein the previously leading product is oriented sideways. The pair are subsequently separated, again by their products being gripped on the projections. Again, two imbricated streams result, each with half of the original conveying rate. 
     It is disclosed in WO 00/24660, EP-A 1 321 410 or EP-A 0 330 868, that a gripper of a gripper conveyor grips and conveys two products together. The products have a displacement in a direction that runs transversely to the edge being gripped. As a consequence, the conveyance rate is doubled with the same speed of the gripper. The separation of the products in a following work step presupposes, however, that once again a conveyor with the original delivery rate is employed. EP-A 1 321 410 describes, for example, that the initially pairwise gripped products are transferred individually into the grippers of a single further conveyor. This must again have the original conveying rate, which in the event of the high rate counts described initially above is not feasible. 
     In the course of increasing the delivery capacity of rotary printing presses, a need has been created for a conveyance method using gripper conveyors that can cope with the increased rate counts and that preferentially is achievable with limited technical costs. It is an object of the invention to provide such a conveyance method and a device appropriate to the execution of that method. 
     BRIEF SUMMARY OF THE INVENTION 
     In method according to the invention for the conveyance of planar products, in particular printed products, a product group consisting of at least two gripped-together products is gripped by a gripper of a gripper conveyor and conveyed in a direction of conveyance. Usually it is applied to products that are rectangular in shape, wherein all product edges run parallel to one another or stand perpendicular to one another. The gripper grips the products together, such that all the products are held. The product edge that next comes to the gripper will be designated as the gripped product edge. According to the invention, at least one of the products within the product group is shifted in a direction of displacement relative to the other product or products of the product group, such that in each case an area of the outside-lying product protrudes past the other product or products. In what follows, this area of the product will be also called the projection. The direction of displacement corresponds to the direction of the gripped product edge or edges. It preferentially, though not necessarily, runs perpendicularly to the direction of conveyance of the gripper conveyor. 
     In the case of folded products, they are displaced relative to one another in the direction of the folded edge; in the case of products with multiple folds, in the direction of the outermost fold. The folded edge is preferentially, though not necessarily, gripped by the gripper. In this embodiment of the invention, the folded edge, thus, determines the direction of displacement. 
     The device according to the invention includes an incoming conveyor for the incoming conveyance of products as well as a gripper conveyor, which is capable of gripping and conveying each respective product group thereof in such a manner that at least one of the products of a product group is displaced relative to the other product or products of the product group in the direction of the gripped product edge or the folded edge. DE-A 292 2450 discloses an example of such a device. 
     The invention makes it possible to easily double or even multiply the conveying capacity of known gripper conveyors, in that groups of products are gripped together by one gripper. By being taken up by the gripper, the products can also be moved in a precise and controlled manner over large distances. Preferentially, the products are arranged in the group such that the edges of at least two products are aligned flush relative to one another. Preferentially, one of these edges is the gripped product edge. The products thereby occupy a defined space and can be held in an especially reliable way. The projections at the pairs or groups of products, which extend in the direction of displacement beyond the area in which the products overlap each other completely, make it possible to easily separate the products again by gripping the projections and moving, wherein a component of that movement is in the direction of displacement. Preferentially, this occurs after the products have been laid on a conveyor belt in imbricated formation or as separated pairs or, as the case may be, groups. At this juncture it is possible to compose a product formation that is customized to the requirements of a post-production process. 
     An example of such a separation step can be found as disclosed in DE-A 2417614, CH 634 530 or EP-A 0 936 169. It creates two imbricated streams, each respectively with half of the original delivery capacity. According to the device, there is preferentially an outgoing conveyor which is capable of taking the products from the gripper conveyor and conveying them in a continuous imbricated stream in an outgoing direction of conveyance. For the separation into two sub-streams the outgoing conveyor preferentially comprises a holding means that grips onto the projections, holds them and moves in a direction, wherein a component of this movement is in the direction of displacement. 
     The products within a product group can be identical to one another or variable, as well as also having different formats. This can, for example, be a matter of multiple magazines or kerfs, or one magazine with additional inserts. The products can be unfolded, however with printed products it is generally concerned with folded products. In this case, the direction of displacement preferentially corresponds to the direction of the folded edge. In the case of a product with multiple folds, the ‘folded edge’ is taken in each case to mean the last appropriate folded edge. In the case that multiple products in a product group are folded, the folded edges point preferentially, though not necessarily, in the same direction. 
     If there are only two products in a product group, the group may also be designated as a product pair. Preferentially a gripper grips two or more product pairs, in which the gripped product edges are arranged such that the products substantially overlap one another, or are displaced relative to one another in a direction transverse to the direction of displacement. Such a product group lends itself to easily being taken from an incoming imbricated formation and also being transferred again to an outgoing imbricated formation. 
     The invention makes it possible to capitalize on the fact that rotary printing presses often produce products as product pairs consisting of in each case two products that are offset relative to one another in a direction of displacement, folded in each other and aligned with one another with respect to their folded edges. Thus, according to the invention, a separation step after the printing press can be done away with, and these product pairs can be transferred immediately to the grippers. 
     However, the method according to the invention can also be used in cases in which the described product groups were manufactured in other ways. For example, the products that are to be taken up can be arranged in an imbricated formation that is composed upon their being taken out of an intermediate storage place which is used for intermediate storage. Moreover, it is possible that the product pairs are arranged in an imbricated formation wherein the product pairs consist of two products that lie on top of or inside of one other. Thus furthermore, it is possible to assemble the product groups by extracting products from a formation that corresponds to two or more imbricated streams that lie on top of one another, as disclosed in WO-A 03/0538131. 
     In a preferred embodiment of the invention, the products are conveyed in an imbricated formation to the gripper conveyor. As a preferred example, the imbricated stream already consists of product groups that are transferred to a gripper in a further step, e.g. of the above described pairs of products folded in each other with a predetermined product spacing. Alternatively, the product groups can be composed into a simple imbricated stream during the conveyance. Here may be considered the method according to EP-A 0 936 169, i.e. composition of product pairs out of an imbricated stream consisting of single products. 
     In a further preferred embodiment of this variant of the invention an imbricated formation consists of product pairs with a regular product spacing. These pairs are grouped into product groups in a further process step, which groups are respectively each transferred to a gripper. In particular, an imbricated formation is composed, which consists of such product groups composed of two or more product pairs, wherein the product groups comprise a regular group spacing under one another. Within a group of products, the product pairs can lie congruently or differentiated, i.e. lie on top of one another with a displacement that is greater than or equal to zero and smaller than the product spacing. Rather than pairs of products, units of more than two products can also be arranged in the described manner. 
     An imbricated stream of overlapping product groups is composed as disclosed for example for single products in EP-A 00139 20 or EP-A 1 321 410. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred embodiments of the invention are depicted in the figures and described thereafter. Showing in pure schematic: 
         FIGS. 1   a - h  several examples of product groups of several products; 
         FIGS. 1   i - m  examples of an imbricated formation consisting of multiple product groups; 
         FIG. 2   a  a device for the execution of the conveyance method according to the invention, wherein in each case two products are gripped by a gripper; 
         FIGS. 2   b - e  several possibilities for the arrangement of the products within a gripper in a view in the direction of displacement when performing a method according to  FIG. 2   a;    
         FIG. 3   a  a device for the execution of the conveyance method according to the invention, wherein in each case four products are gripped by a gripper; 
         FIGS. 3   b - e  several possibilities for the arrangement of products within a gripper in a view in the direction of displacement when performing a method according to  FIG. 3   a;    
         FIG. 4  the division of an imbricated stream consisting of a plurality of product groups into two sub-streams; 
         FIGS. 5   a+b  a further example of the execution of the method according to the invention in overview and, respectively, side view, wherein in each case two products are taken from an imbricated formation consisting of two imbricated sub-streams lying on top of one another; 
         FIG. 5   c  a modification of the method according to  FIG. 5   a+b;    
         FIGS. 6   a+b ,  7   a+b  further examples of the execution of the method according to the invention in overview and, respectively, side view, wherein in each case four products are taken from an imbricated formation consisting of two imbricated sub-streams lying on top of one another; 
         FIG. 8  a modification of the method according to  FIG. 6   a+b  or  7   a+b;    
         FIG. 9  an example of the composition of an outgoing imbricated formation consisting of two imbricated sub-formations. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1   a - h  give an exemplary view of several product groups  100  in the form of product pairs  30 ,  30 ′ ( FIGS. 1   a - f ) or pairs of pairs ( FIGS. 1   g+h ), which in the conveyance method according to the invention are conveyed together in one gripper. It is concerned with groups  100  of respectively two planar products  10 ,  10 ′,  20 ,  20 ′ with a basically rectangular shape in a defined spatial relationship with one another, i.e. with a minimum of overlap in an overlapping area  32  (represented with shading). In normal cases the product edges run parallel to one another. In the execution of the method according to the invention, in each case, one of the product edges  12 ,  22  of the product  10 ,  20  is arranged in spatial proximity to the gripper, which grips preferentially in the overlapping area  32 . These product edges  12 ,  22 ,  12 ′,  22 ′ will also be designated as gripped product edges. According to the invention the products of a product group  100  have a displacement relative to one another in a displacement direction A defined by the gripped product edges  12 ,  22 ,  12 ′,  22 ′, such that in each case a lateral projection  14 ,  24 ,  14 ′,  24 ′ of width d or as the case may be d′ is formed, wherein it is possible that d=d′. Within the product group  100  the products can have a displacement s perpendicular to the direction of displacement A ( FIG. 1   a ). In the case of two product pairs  30 ,  30 ′, between these a displacement s′ can exist (instead of or in addition to the displacement within the pairs) perpendicular to the direction of displacement A ( FIG. 1   g ,  1   h ). 
       FIG. 1   a  shows, in overview, the most general case of a product group  100  in the form of a pair  30  with two products  10 ,  20 , which are folded or unfolded. According to the  FIGS. 1   b - h  at least one product  10 ,  10 ′,  20 ,  20 ′ of a product group  100  is folded and comprises a folded edge  13 ,  13 ′,  23 ,  23 ′, which here corresponds to the gripped edge  12 ,  12 ′,  22 ,  22 ′. If within a group  100 , multiple folded products  10 ,  10 ′,  20 ,  20 ′ exist, the folded edges  13 ,  13 ′,  23 ,  23 ′ preferentially are parallel with one another. The displacement s within a pair is frequently zero, particularly if the products are aligned together with one another at their folded edges  13 ,  13 ′,  23 ,  23 ′. 
     In  FIG. 1   b  a product pair  30  is depicted of two similarly-sized products  10 ,  20  folded in with one another, whose gripped edges  12 ,  22 , which correspond to the folded edges  13 ,  23 , are aligned with one another. Projections  14 ,  24  are formed as shown in the direction of displacement A with substantially similar widths d as well as d′. Such a product group is produced by, for example, a rotary printing press as disclosed e.g. in DE-A 2417614 or CH 634 530. 
       FIG. 1   c  depicts a product group  100  of two folded products  10 ,  20  of substantially similar size which lay on top of one another with a lateral displacement d, d′ in the direction of displacement A. Thus, again projections  14 ,  24  of substantially similar widths d as well as d′ are formed. Such a product group can, for example, be produced by a method analogous to the method disclosed in EP-A 0 936 169 or through the consolidation of two imbricated streams. 
       FIGS. 1   d  and  1   e  depict a further product group  100  with products  10 ,  20  of dissimilar size. In  FIG. 1   d , the smaller product  20  is shown with its folded edge  23  flush against the folded edge  13  of the larger product  10  (i.e. s=0). 
       FIG. 1   f  largely corresponds to  FIG. 1   b  with the difference that the inside-lying product  20  is not folded. In a manner analogous to  FIG. 1   c , the non-folded product  20  can also lie on the folded product  10 . 
       FIGS. 1   g  and  1   h  depict product groups  100 , which in each case consist of two product pairs  30 ,  30 ′. In  FIG. 1   g , the product pairs  30 ,  30 ′ correspond to  FIG. 1   b  and lie on top of one another with a displacement of width s′ perpendicular to the direction of displacement A. In  FIG. 1   h , the product pairs  30 ,  30 ′ substantially correspond to  FIG. 1   c  with the difference that the gripped edges  12 ,  22 ,  12 ′,  22 ′ within a pair are spaced apart one in front of the other by the distance s. Between the product pairs  30 ,  30 ′ there is again a displacement of width s′ perpendicular to the direction of displacement A. In both cases the displacement s, s′ can also have a value of zero (see  FIG. 1   i ,  1   m ). The overlapping area  32  in which the gripper preferentially grips is again shown with shading. In order to separate, the lateral projections  14 ,  14 ′,  24 ,  24 ′ would be gripped. 
       FIGS. 1   i - m  depict several examples of an arrangement of products in an imbricated formation, in particular, though not necessarily, with the goal of transferring groups of several products to the gripper. 
     In  FIG. 1   i , the imbricated formation consists of product groups  100 , which in each case feature two product pairs  30 ,  30 ′ of in each case two products  10 ,  10 ′,  20 ,  20 ′. The product pairs  30 ,  30 ′ correspond to  FIG. 1   b . Within a group  100  they lie on top of one another without displacement relative to one another (s′=0). The group spacing a is constant between two groups that follow one another. This formation is preferentially produced as a simple imbricated formation, consisting of product pairs with the same spacing, composed, e.g. in the method according to EP-A 0013920. 
     The imbricated formation according to  FIG. 1   k  corresponds to  FIG. 1   i  with the difference that the product pairs  30 ,  30 ′ within a product group  100  are displaced relative to one another in a displacement s′ in the direction of conveyance F 1  (cf.  FIG. 1   g ). 
     The imbricated formation according to  FIG. 1   l  is a simple imbricated stream with group spacing a of product pairs  30 , which are assembled according to  FIG. 1   c .  FIG. 1   m  corresponds to  FIG. 1   i  with the difference that in each case two pairs  30 ,  30 ′, formed according to  FIG. 1   c , lie on top of one another. 
     The depicted imbricated streams can not only be used as the incoming formation for the method according to the invention, but also be generated as the outgoing formation by being laid down by the gripper. 
       FIG. 2   a  gives a schematic depiction of a device for the execution of the method of conveyance according to the invention. It features a gripper conveyor with a plurality of grippers  42  which move along the length of a conveyance line  44 . It again features an incoming conveyor  50  as well as an outgoing conveyor  60 . Both are designed with a conveyor belt  52 ,  62  and are thereby equipped to convey the products  10 ,  20 , which are consolidated together in product pairs  30 , in an incoming or as the case may be outgoing imbricated stream S, S′ in an incoming or as the case may be outgoing direction of conveyance F 1 , F 3 . The individually-controllable individual grippers  42  of the gripper conveyor  40  take up the product pairs  30  in a pre-determined way from the incoming imbricated formation S and lay them in the outgoing imbricated formation S′ on the conveyor belt  62  of the outgoing conveyor  60 . During the conveyance by the gripper conveyor  40 , further steps that are not depicted here may be performed. It can also be imagined that instead of an outgoing conveyance device  60  there can, for example, be a staple binding module or another mechanism for post-processing. 
     The incoming imbricated formation S already consists of product pairs  30  which are assembled for example as in  FIG. 1   a - c  or  1   e , i.e. laying within or upon one another with a lateral displacement whereby lateral projections  14 ,  24  are formed. The product pairs  30  have a constant group spacing a. The direction of displacement A is oriented perpendicularly to the incoming direction of conveyance F 1 . The folded edges  13 ,  23  here lie on top and oriented toward the incoming direction of conveyance and are to be gripped by the gripper. 
     The gripper  42  grips the product pairs  30  in each case in the area of the folded edge  13 ,  23 . The opening and closing movement is controlled in a known manner by controlling mechanisms. The product pairs  30 , here hanging, are conveyed in a further direction of conveyance F 2  by the gripper conveyor  40  wherein the gripper jaw points downward. The gripper  42  can, however, also have an orientation towards or away from the further direction of conveyance F 2 . The edges which are opposite from the folded edges  13 ,  23  of the product  10 ,  20  can hang freely downward or be supported by some further means not depicted here. 
     In the outgoing imbricated formation S,′ the product pairs  30  have a group spacing a′ which can be identical to or different from the original group spacing a. In the examples shown, the orientation of the product pairs  30  in the outgoing imbricated formation S′ corresponds to that of the incoming imbricated formation S. However, it is in principle possible that any arbitrary formation can be created, with e.g. with folded edges trailing. 
       FIGS. 2   b - e  depict views in the direction of displacement A of examples of product groups as well as pairs  100 ,  30  during transport by the grippers  42  according to  FIG. 2   a . Therefore, the projections  14 ,  24  are not visible. In each case, the gripper  42  grips in the overlapping area  32  (cf.  FIG. 1   a - e ). In  FIG. 2   b , a product pair  30  that is constructed as in  FIG. 1   b  or  1   d  is conveyed. In  FIG. 2   c  a product pair  30  that is constructed as in  FIG. 1   c  is conveyed. In  FIG. 2   d  a product pair  30  that is constructed as in  FIG. 1   f  is conveyed. In  FIG. 2   e  a product pair  30  that is constructed as in  FIG. 1   c , but with the difference that one of the products  20  is not folded, is conveyed. 
       FIG. 3   a  depicts the device of  FIG. 2   a  in the execution of a variation of the conveyance method according to the invention, in which a product group  100  of in each case four products  10 ,  10 ′,  20 ,  20 ′ (as the case may be two product pairs  30 ,  30 ′) is gripped by a gripper  42 . The incoming imbricated formation S is thereby initially constructed as in  FIG. 2   a  of product pairs  30 ,  30 ′ with a regular group spacing a. Through the action of a retarding means  54  the group spacing a is altered, such that the products are pushed together into groups  100  of two or more product pairs  30 ,  30 ′. Here two product pairs  30 ,  30 ′ are in each case dedicated to one group (the product pairs  30 ,  30 ′ can be either variable or identical). In each case, a product pair  30  has a spacing a 1  that is decreased relative to the following product pair  30 ′, and which can also be zero, as well as a spacing a 2  that is increased relative to the preceding product pair  30 ′ (a 1 +a 2  corresponds to the group spacing a). The above-mentioned retarding means  54  is for example an impulse that is timed to and brought to bear on the imbricated stream S and moves the product pairs  30 ,  30 ′ together by its action thereupon. However, other methods are possible in order that in each case two or more product pairs  30 ,  30 ′ are transferred into a gripper  42 . It is also possible that the assembly of the product groups  100  for this purpose is accomplished by the action of the gripper  42  itself, without necessitating that the product pairs  30 ,  30 ′ be pushed together beforehand (see e.g.  FIG. 5   b ). 
     Here the gripper  42  grips in each case two product pairs  30 ,  30 ′ in the area of the leading edges  12 ,  22 ,  12 ′,  22 ′, which here correspond to the folded edges  13 ,  23 ,  13 ′,  23 ′. The product pairs  30 ,  30 ′ in the gripper have a displacement relative to one another in a direction s perpendicular to the direction of displacement A, which may, but need not, correspond to the spacing a 1 . The displacement a can also be zero. 
     The gripper  42  lays the product pairs  30 ,  30 ′ in groups on the conveyor belt  62  of the outgoing conveyor  60 . The outgoing imbricated formation can already upon being laid down feature a regular group spacing a′, which corresponds, e.g. to the displacement s′. Alternatively, an alternative group spacing can be created here and either retained or later regularized. 
       FIG. 3   b - e  depict examples of product groups  100 , consisting in each case of two product pairs  30 ,  30 ′, shown in a view in the direction of displacement A during transportation in the gripper  42  of the device according to  FIG. 3   a . The product pairs  30 ,  30 ′ have in each case a displacement s in a direction perpendicular to the direction of displacement A. In  FIG. 3   b , two product pairs  30 ,  30 ′ corresponding to  FIG. 1   g  are held. In  FIG. 3   c , two product pairs corresponding to  FIG. 1   h  (with s=0 and s′&gt;0) are held.  FIGS. 3   d  and  3   e  correspond to  FIG. 3   b  as well as  3   c , with the difference that in each case one of the products  20 ,  20 ′ of the product pair  30 ,  30 ′ is not folded. 
       FIG. 4  depicts a possibility for the further processing of the outgoing imbricated formation S′ that is appropriate in order to further separate the product pairs  30  into single products  10 ,  20 , which are respectively further transported in separated imbricated sub-streams T 1 , T 2 . To that end, a separation device  70  features two groups of holding elements  72 ,  74  which respectively are movable along the length of a first as well as a second movement line  76 ,  78 . These holding elements  72 ,  74  are able to grip onto the lateral projections  14 ,  24  and pull the products apart from each other by transporting them in the outgoing direction of conveyance F 3  with a component of movement perpendicular to the direction of displacement A. Instead of separate, movable holding elements  72 ,  74 , continuous belts or stationary conveyance rollers may be present. A design can be utilized as per DE-A 2417614, CH 634 530 or EP-A 0 936 169, which are incorporated by reference. 
     By these means, formations with irregular product spacing, products in imbricated formations here of product units of several products that are stacked congruently or stacked one on top of another or displaced relative to one another, or formations consisting of two or more imbricated sub-formations laying on top of one another can also be pulled apart into sub-formations in a direction transverse to the direction of conveyance. 
       FIGS. 5   a+b  depict an overview as well as a side view of a further example of the execution of the method according to the invention. An incoming imbricated formation S consists of two imbricated sub-streams S 1 , S 2  with in each case identical group spacing a, which lie on top of one another on a conveyor belt  52 . The imbricated sub-streams S 1 , S 2  consist of first as well as second products  10 ,  20 , which can be, but need not be, folded. The products  10 ,  20  can also feature sub-products (not shown here, but see  FIG. 6   b ). The leading edges  13 ,  23  of the products  10 ,  20 , which are later gripped, lie in each case on top of the preceding product. They define a direction of displacement A which lies perpendicular to the incoming direction of displacement F 1 . In this direction, the imbricated sub-streams S 1 , S 2  at hand have a displacement d which is composed as the products  10  of the upper imbricated sub-stream S 1  are laid upon the lower imbricated sub-stream S 2 . A method for this layering of imbricated streams is disclosed in WO 03/053831, which is incorporated by reference. 
     According to the invention, the gripper  42  here grips, in each case, two products from the resulting imbricated formation S, wherein a product  10  from the upper imbricated sub-stream S 1  as well as a product  20  from the lower imbricated sub-stream S 2  is grasped. Because of the displacement d of the imbricated sub-streams S 1 , S 2 , a product pair  30  is formed in the gripper  42 , in which the individual products  10 ,  20  lie on top of one another and again are displaced relative to one another to the extent of the displacement d. The product pair  30  is depicted in, e.g.  FIG. 1   c.    
     The imbricated sub-streams S 1 , S 2  can also be shifted out of phase, so that a product pair is formed with a displacement d in the direction of the product edge as well as a displacement s perpendicular thereto ( FIG. 1   a ,  FIG. 5   c ). 
       FIGS. 6   a+b ,  7   a+b  depict in side view ( FIG. 6   a ,  7   a ) as well as overview ( 6   b ,  7   b ) further examples of a method according to the invention, in which the incoming imbricated formation S consists of two imbricated sub-streams S 1 , S 2 , one lying on top of the other. The imbricated sub-streams S 1 , S 2  consist in each case of several product units, as here two sub-products, wherein the product units have a regular group spacing a between one another. The  FIGS. 6   b ,  7   b  depict two variants of how the imbricated sub-streams S 1  S 2  can appear, in order to reach the goal according to the invention that into the gripper  42  may be transferred the gripped edges of a product group  100  with a sideways displacement of at least two products perpendicularly to direction A. The side view  FIG. 6   a ,  7   a  is the same for both variants. 
     In  FIG. 6   b , the product unit in each case consists of two sub-products  10   a ,  10   b  and as the case may be  20   a ,  20   b , which lie on one another without relative displacement and can in each case be identified with a product  10 ,  20  from the above examples. As in  FIGS. 5   a+b , the resulting products  10 ,  20  are arranged in separate imbricated sub-streams S 1 , S 2  and laid on top of each other with a lateral displacement d. A gripper  42  grips, in each case, two products  10 ,  20  consisting of the described sub-products  10   a ,  10   b  and as the case may be  20   a ,  20   b . The sub-products  10   a ,  10   b  from the upper imbricated sub-stream S 1  therefore have a displacement d relative to the sub-products  20   a ,  20   b  from the lower imbricated sub-stream S 2 , such that overall, a product group  100  with the desired characteristics can be composed. 
     In  FIG. 7   b , the product units consist of product pairs  30 ,  30 ′ with in each case two products  10 ,  20 ,  10 ′,  20 ′, which already feature a displacement d relative to one another. The product pairs  30 ,  30 ′ are, e.g., as featured in  FIG. 1   a - f . The imbricated sub-streams S 1 , S 2  are here laid on top of one another without a sideways displacement. The gripped product groups correspond to, e.g.,  FIG. 1   g  or  1   h  (with s′=0). 
     The concepts from  FIGS. 6   b  and  7   b  can also be combined, e.g. in that the imbricated sub-streams S 1 , S 2  may be laid on top of one another with an additional sideways displacement. It is also possible, in each case, that only one product or more than two products can exist in one product unit; furthermore the numbers of products per product unit in the imbricated sub-streams do not need to be the same. 
       FIG. 8  depicts, in a manner analogous to  FIG. 5   c , the composition of a product group  100 , in which in each case two products are situated with an additional displacement s perpendicular to the direction of displacement A, which is created by a phase shift of size s between the imbricated sub-streams S 1 , S 2 . 
     In the examples of  FIGS. 5   a - c ,  6   a+b ,  7   a+b ,  8 , there may also be more than two imbricated sub-streams with constant group spacing a laid on top of one another, to produce in the same manner with a gripper  42  product groups  100  consisting of more than two, or as the case may be more than four, products. 
       FIG. 9  depicts schematically a further example of the production of an outgoing imbricated formation S′, which can be further transported by an outgoing conveyor  60 . An outgoing imbricated sub-stream S 1 ′, consisting of single product pairs  30 ′, has already been formed on the conveyor belt  62  of the outgoing conveyor  60 . Through the laying thereon of further pairs of products  30  a second outgoing imbricated sub-stream S 2 ′ is created as the gripper  42  is opened at a common release point or, as the case may be, transfer point  80 . The first imbricated sub-stream S 1 ′ can have an arbitrary origin, e.g. from out of a storage place. 
     The examples depicted make clear that the invention makes possible a high degree of flexibility. In particular, product groups of nearly any arbitrary configuration, consisting of identical or also variable folded or unfolded products, can be transferred into the gripper. This occurs very simply because the products are taken in groups out of a simple imbricated formation or a more complex formation consisting of several imbricated sub-streams lying on top of one another. The conveyance capacity of the gripper conveyor is significantly increased thereby. If desired, the later whole or partial separation of the product groups into single products can be achieved by simple means, due to the sideways projections between at least two products in a product group. To this end, the product groups are preferably laid in an outgoing imbricated formation. 
     Besides by grippers, the product groups here depicted can be conveyed by another means of conveyance that allows a controlled and defined movement. Here may be considered a belt conveyor that preferentially clamps the products between two belts, preferably in an imbricated formation. The products can also be clamped at a product edge that runs in the direction of conveyance. In this case the displacement of the product in a product group or as the case may be a product pair is preferentially transverse to the gripped edge, i.e. transverse to the direction of conveyance. 
     In addition, also without a transfer to a gripper conveyor, forming an imbricated formation that consists of product groups which comprise two or more products, at least one of which comprises a displacement transverse to the direction of conveyance or transverse to the folded edge (direction of displacement), out of a simple imbricated formation has advantages. In particular in the case of a displacement transverse to the direction of conveyance, an extremely simple separation of the product groups ensues, in which the protruding product is pulled out in the direction of displacement.