Patent Publication Number: US-2004052615-A1

Title: Wire comb binding element method and device

Description:
[0001] The invention relates to a methods and devices for bending wire binding elements that are used in a wire comb binding.  
       [0002] Methods for production of booklets, which use so-called Wire-O® wire binding elements in various sizes, are known, for example, from the European Patent application s 0 095 243 A1 and 0 095 245-B1.  
       [0003] Wire-O® binding elements are defined as wire loops that are spaced parallel to each other and have a loop length L, a loop spacing A and a wire diameter D, as depicted in FIG. 2 a,  and are shaped into a ring using appropriate closure devices.  
       [0004] The binding devices for the patent applications indicated above are thus configured so that it is possible to process pre-formed Wire-O® wire binding elements with different loop intervals and lengths. The pre-formed Wire-O® wire binding elements thus consist of wire loops that form a C-shaped or ω-shaped structure. The C-shaped or ω-shaped structure is closed after the sheet-form printing materials have been threaded into the wire binding element through their holes in such a manner that a circular ring binding is produced. The ω-shaped structure is produced if a bead was incorporated in the center of the loop of the wire binding element. A bead of this type can ease the closing operation of the pre-formed Wire-O® wire binding element.  
       [0005] Generally, there exists the disadvantage in the aforementioned devices that, for the binding of booklets of varying format and thickness, the needed wire binding elements must be made available to the binding device in the form of several already formed binding element stocks, e.g. as reel-fed material or as elements cut to binding length. In order to be able to bind these varying booklet formats and thicknesses, a considerable number of stocks is necessary.  
       [0006] Moreover, for a size change of the booklets to be produced, the devices, which are suited for transport and for processing, must be adapted to the requirements of the different wire binding elements. This retooling requires complicated designs of the transport and binding devices and makes it so the binding process only remains economical if greater piece counts of a particular booklet thickness are produced in one format. Smaller runs are therefore uneconomical to produce and, due to the machine adaptation, require a greater amount of time.  
       [0007] From German Patent 28 47 700 A1, a method is known for producing a wire binding for books in sheets, etc. in which a wire that is continuously drawn from a stock is shaped into a wavy structure by bending back and forth, the wavy structure wire structure then being bent into a C-shaped form, transverse to the plane of the waves. Forming rollers having specified diameters are used for bending, so that it is only possible to produce wire binding elements having unalterable loop spacing and lengths.  
       [0008] Using a device for producing booklets of varying format and thickness via wire comb binding, with which the wire binding elements can be produced directly in the binding process corresponding to its requirement and the particular format and thickness of the booklets to be bound, each wire loop of the wire comb must be bent together into a ring. In so doing, one must take into account that the radius of the resulting ring is a function of the stack thickness of the sheet-form printing materials and, thus, of the particular wire loop length.  
       SUMMARY OF THE INVENTION  
       [0009] According to various aspects of the invention, methods and devices are provided for bending wire binding elements that are adapted in particular to varying thicknesses of stacks of sheet-form printing materials, preferably without retooling.  
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0010]FIG. 1 presents a schematic diagram of the structure of an embodiment of a device according to one aspect of the invention.  
     [0011]FIG. 2 a  presents an illustration of a flat, looped wire binding element.  
     [0012]FIG. 2 b  presents an illustration of a looped wire binding element in a C-shape.  
     [0013]FIG. 3 presents an embodiment of a booklet bound via a looped wire binding element that is bent overall in an O-shape.  
     [0014]FIG. 4 a  presents an embodiment of a booklet bound using a plurality of individual wire binding elements.  
     [0015]FIG. 4 b  presents an embodiment of a bound booklet using a plurality of individual wire binding elements that are spaced apart from each other.  
     [0016]FIG. 5 presents a diagrammatic illustration of the C-formers during centering of the points of the wire binding element.  
     [0017]FIG. 6 presents a diagrammatic illustration of the C-formers during centering of the base side of the wire binding element.  
     [0018]FIG. 7 presents a diagrammatic illustration of the C-formers with a wire binding element inserted in the tabs.  
     [0019]FIG. 8 presents schematic diagram of the insertion or clamping position of the C-formers.  
     [0020]FIG. 9 presents a diagrammatic illustration of the O-formers.  
     [0021]FIG. 10 presents a diagrammatic illustration of the pivot points of the C-formers and O-formers inside the looped wire binding elements.  
     [0022]FIG. 11 presents a diagrammatic illustration of the procedural sequence of the present invention. 
    
    
     DETAILED DESCRIPTION  
     [0023] Various aspects of the invention are presented with reference to FIGS.  1 - 11 , which are not drawn to any particular scale, and wherein like components in the numerous views are numbered alike. Referring now specifically to FIG. 1, the overall structure of an device of the present invention, of which, for the sake of simplified description, only the components that are essential to the invention are depicted or explained. Additional drive and/or guiding means as well as electrical/electronic circuits, which are generally known and required for the operation of the device, are not illustrated or are described only in general form.  
     [0024] The device according to one aspect of the present invention is essentially comprised of a pair of C-formers  50 ,  50 ′, which together bend a flat, looped wire binding element  41  into a preliminary C-shape  41   c  and a pair of O-formers that bend the looped wire binding element  41  that is bent into C-shape  41   c  into a closed O-shape  41   o  for the loose binding of sheet-form printing materials  11  into booklets  10 .  
     [0025] A stack of sheet-form printing materials  11 , which have a plurality of holes  12  and when laid one on top of the other with the outer edges in alignment form an essentially straight passage for loops S of flat wire binding element  41 , is clamped into a pincer  70 . The sheet-form printing materials could, for example, be delivered by pincers  70 , especially if the device of the present invention belongs to a higher order system. In another embodiment, pincers  70  are a fixed component of the device of the present invention, especially if the embodiment is a tabletop device for loose binding of booklets  10 .  
     [0026] C-formers  50 ,  50 ′ are each mounted on a shaft  51 ,  51 ′ and are driven, guided and controlled in such a manner that they can execute a rotary movement around the particular shaft  51 ,  51 ′, as is indicated by the corresponding arrows in FIG. 1. Also provided are stepper motors, guides and control means (not shown), which are known to the person of ordinary skill in the field, for both C-formers  50 ,  50 ′, so that C-formers  50 ,  50 ′ also travel in the X-direction and Y-direction in a controllable manner. The use of stepper motors permits an especially great flexibility in the drive and configuration of the movement of C-formers  50 ,  50 ′; the same is true for O-formers  60 ,  60 ′.  
     [0027] O-formers  60 ,  60 ′ also have corresponding drives, guiding devices and control means (not shown) that are known to the person of ordinary skill in the field for rotary movements around the particular shaft  61 ,  61 ′ and along the X-direction or Y-direction. Furthermore, drives, guiding means and control means for the O-formers  60 ,  60 ′ are provided that can be used to move O-formers  60 ,  60 ′ in the Z-direction. The Cartesian coordinates that are used in this context are indicated in the coordinate axes in FIG. 1.  
     [0028] C-formers  50 ,  50 ′ have a geometric shape that permits a centering and a gripping of the looped wire binding elements  41 . For this purpose, tabs  52  are provided for gripping, or clamping looped wire binding element  41  as well as centering elements  53 ,  53 ′ and centering funnels  54 ,  54 ′.  
     [0029] O-formers  60 ,  60 ′ also have tabs  62 ,  62 ′ that are used for clamping and bending looped wire binding element  41  into C-shape  41   c  and are described in greater detail below.  
     [0030] C-formers  50 ,  50 ′ positioned one below the other and respective O-formers  60 ,  60 ′, one below the other, are not substantially different in structure except for the mirror symmetry; however, in addition, especially for the description of the method of the present invention, one speaks of a first C-former  50  and a second C-former  50 ′ as well as a first O-former  60  and a second O-former  60 ′. In this context, first C-former  50  or first O-former  60  are each characterized in that they are arranged on the side of the sheet-form printing materials  11 , at which base side  41   k  of looped wire binding element  41  is situated. As a result it turns out that second C-former  50 ′ or second O-former  60 ′ are each characterized in that they are arranged on the side of the sheet-form printing materials  11 , at which points  41   s  of loops S of looped wire binding element  41  are situated.  
     [0031] In FIG. 2 a  a looped wire binding element  41  is illustrated with four loops S. Loops S have a spacing A from peak  41   s  to peak  41   s,  and a wire diameter D, a loop length L and a quantity N of loops S. Moreover, the base sides are marked with reference number  41   k  and the loop points of wire binding element  41  are marked with reference number  41 s. Spacing A thus corresponds to spacing A′ of holes  12  in sheet-form printing materials  11  (see FIG. 4 b ). However, the number of holes N′ in sheet-form printing material does not necessarily correspond, as explained below, to the number N of loops S, but rather represents a maximum for the reasonable number N of loops S of wire binding element  41 .  
     [0032] The loop length L specifies the diameter of wire binding element  41  in closed O-shape  41   o  and can be made a function of the number of sheet-form printing materials  11 . The diameter of a wire binding element  41  that is bent into a O-shape  41   o  is selected so that the bound booklet  10  gets an aesthetic exterior, it is easy to turn its pages and is easy to stack. In FIG. 2 b,  a looped wire binding element  41  in C-shape  41   c  is shown. The looped wire binding element  41  in C-shape  41   c  represents an intermediate product, and it also can be purchased in a similar form for the production of Wire-O® bindings. However, in the device of the present invention and in the method of the present invention, in contrast to the prior art, a booklet that is to be bound is already located inside the loops if the wire binding element  41  obtains the C-shape  41   c.    
     [0033] Shown in FIG. 3 is a finished bound booklet  10  with a wire binding element  41  that is bent completely into an O-shape  41   o  and has a continuous binding. FIG. 4 a  shows a single binding that is comprised of wire binding elements  41 ′, which each have only a single loop, and for each hole  12  in the printing stock precisely one wire binding element  41 ′ is used. Illustrated in FIG. 4 b  is a wire comb binding that consists of several wire binding elements  41 ′, for example multi-loop ones, which are spaced from each other in such a manner that holes  12  remain open. Any other combination from the aforementioned possibilities is clear to the person of ordinary skill in the field.  
     [0034] Shown in FIG. 5 are details of the centering of a flat, looped wire binding element. This shows, on the one hand, centering funnels  54 ,  54 ′ into which the points  41   s  of the flat, looped wire binding element are inserted. On the other hand, it shows wedge-shaped centering elements  53  (see also FIG. 6) that push against the base side  41   k  of wire binding element  41  between the ends of loops S and thereby set the position of loops S on base side  41   k.  In this context, the width of the section of centering element  53 , which is pushed between the legs of loop S, is essentially such that the legs of loop S are parallel to each other. In this way, the parallelism of loops S to each other is supported.  
     [0035] As is recognizable in FIGS.  5  to  7 , tabs  52 ,  52 ′, which are used to grasp and clamp the looped wire binding element  41 , are continuous profiles for all loops S of wire binding element  41 , which on their part have no additional components. The position of the wire binding element within these tabs  52 ,  52 ′, as illustrated in FIG. 7, is secured solely by clamping, the clamping being achieved by a rotation of C-formers  50 ,  50 ′. Due to this structure with a continuous profile of tabs  52 ,  52 ′, an especially great stability of C-formers  50 ,  50 ′ can be achieved in this area. Moreover, the manufacturing effort is comparatively little.  
     [0036] The principle of clamping the wire binding element  41  is shown in detail in FIG. 8. Shown in FIG. 8 is first C-former  50  in an insertion position. Lower tab flank  56  and opposing clamp flank  55  are not yet in contact with wire binding element  41 . First C-former  50  is in this insertion position when approaching a flat wire binding element that is held by O-former  60 ,  60 ′ or a comb-threading device (not shown). Second C-former  50 ′ is shown in FIG. 8 already in a clamping position. To do this, second C-former  50 ′ is swung counterclockwise around a pivot point P 1 ′ (see FIG. 10) with respect to the insertion position, until bottom tab flank  66 ′ and clamp flank  65 ′ of second C-former  50 ′ first contact flat wire binding element  41  and when swung further, in this case in the counterclockwise direction, a great enough pressure is developed between flanks  65 ′,  66 ′ and the wire binding element that wire binding element  41  can no longer slip.  
     [0037] In FIG. 9, the structure of O-formers  60 ,  60 ′ is shown diagrammatically. O-formers  60 ,  60 ′ have a number of individual bending elements  64 ,  64 ′ that can each be attached to individual O-formers  60 ,  60 ′ along a groove  66 ,  66 ′. Each bending element  64 ,  64 ′ has a hooked tab  62 ,  62 ′ with a flat underside that is joined on one side to the bending element body of bending element  64 ,  64 ′. In this context hooked tabs  62 ,  62 ′ of the bending elements are symmetrically mounted on first O-former  60  so that all tabs of both O-formers  60 ,  60 ′ point in the same direction.  
     [0038] The length of tabs  62 ,  62 ′ is adapted to the loop shape of wire binding element  41 . On the one hand, tabs  62 ,  62 ′ on the inner side are longer than the width of loops S, so that each loop S can be securely grasped with a tab  62 ,  62 ′. On the other hand, tabs  62 ,  62 ′ are shorter in overall length than the distance between two loops S.  
     [0039] As described above, O-formers  60 ,  60 ′ are equipped with an additional drive in the Z-direction. Due to a combination of a movement in the Y-direction and Z-direction of O-formers  60 ,  60 ′, tabs  62 ,  62 ′ first dip between loops S of a wire binding element  41  that is inserted in the device of the present invention and then move in the Z-direction above the loops in order then to clamp and bend them by rotating O-formers  60 ,  60 ′ in a manner similar to the movement of C-formers  50 ,  50 ′ that is described above.  
     [0040] The clamping and bending mechanism runs in the X-Y plane as described above. The clamping of a wire binding element  41  by rotating C-formers  50 ,  50 ′ or O-formers  60 ,  60 ′ can thus be achieved by rotation both toward sheet-form printing materials  11  and away from sheet-form printing materials  11 .  
     [0041] In FIG. 10, the position of pivot points P 1 , P 1 ′, P 2 , P 2 ′ inside the wire binding element is shown in diagrammatic illustration. It should be pointed out that, although the pivot points are shown in FIG. 10 in reference to a flat wire binding element  41 , the inner pivot points P 2 , P 2 ′ are actually inside the wire binding element even if the wire binding element is not flat, for example, if it is C-shaped.  
     [0042] The tabs  62 ,  62 ′ of O-formers  60 ,  60 ′ have chamfers  67 ,  67 ′ on their sides facing away from loops S in the clamping position. These chamfers  67 ,  67 ′ facilitate the dipping of bending elements  64 ,  64 ′ between the loops.  
     [0043] The movement sequence of the device of the present invention during execution of the method of the present invention is explained in detail below in reference to FIGS.  11 - 1  to  11 - 17 . The movement sequences in this method are controlled by a controller (not shown) that is known from the prior art for the various stepper motors (also not shown) that are known to the person of ordinary skill in the field and are responsible for the movement of C-formers  50 ,  50 ′ or  60 ,  60 ′. In this context, the speed profiles that are required for this may, for example, be calculated or read from tables; the speed profiles of the movements of the individual drives are in particular a function of loop length L of looped wire binding element  41 .  
     [0044] In FIG. 11- 1  the device of the present invention is in a base position. A stack of sheet-form printing materials with aligned holes  12  are clamped in pincers  70  so that holes  12  of sheet-form printing material  11  are located in a comb-threading plane for wire binding element  41 . C-formers  50 ,  50 ′ are located above the comb-threading plane, O-formers  60 ,  60 ′ are located beneath the comb-threading plane and, depending the thickness of the booklets  10  to be bound, are spaced in such a manner that in the assumed position they act as fan-out inhibitors for sheet-form printing materials  11 , especially if pincers  70  swing sheet-form printing materials  11  from below into the planned position. In this way individual sheet-form printing materials  11  that have spread apart are aligned.  
     [0045] If sheet-form printing materials  11  are in the planned position, second C-former  50 ′ moves downward into the centering position of the flat, looped wire binding element  41  as illustrated in FIG. 11- 2 . Second C-former is in the centering position if centering funnels  65 ′ of second C-former  50 ′ are aligned with holes  12  of sheet-form printing materials  11 . O-formers  60 ,  60 ′ run together beneath the comb-threading plane in the X-direction until sheet-form printing materials  11  are aligned. Next, a flat wire binding element  41  is threaded/combed into sheet-form printing materials  11  through holes  12 . Looped wire binding element  41  is pushed in up to the stop with points  41   s  in centering funnels  65 ′ of second C-former  50 ′. Advantageously, wire binding element  41  is held in this position with a comb-threading device, but a manual introduction of wire binding element  41  is also possible.  
     [0046] On the other hand, this can also involve a plurality of wire binding elements  41 ,  41 ′,  41 ″, as is described above and shown in FIGS. 4 a  and  4   b.  For the sake of simplicity, a single wire binding element  41  is assumed, although a plurality of wire binding elements  41 , 41 ′,  41 ″ does not represent a difference for the method of the present invention.  
     [0047] In the next step, which is illustrated in FIG. 11- 3 , O-formers  60 ,  60 ′ move up in the Y-direction and dip in between loops S of wire binding element  41 .  
     [0048] Next, O-formers  60 ,  60 ′ approach the correct mesh point for C-shape  41   c  to be produced. This C-shape  41   c  that is to be produced is in particular a function of loop length S and, consequently, the diameter of the finished O-shape and, thus, the thickness of booklet  10  that is to be bound. Then, O-formers  60 ,  60 ′ move in the Z-direction with their tabs  62 ,  62 ′ above loops S until tabs  62 ,  62 ′ cover the width of loops S.  
     [0049] As illustrated in FIG. 11- 4 , O-formers  60 ,  60 ′ then clamp wire binding element  41  by rotation around preliminary pivot points (not shown) toward booklet  10 . Up to this moment, flat, looped wire binding element  41  is in centering funnels  65 ′ of the second C-former with points  41  s against the stop. As soon as wire binding element  41  is clamped in this position by O-formers  60 ,  60 ′, a comb-threading device can be removed or wire binding element  41  can be released in another way, because for the remainder of the method of the present invention, except for the centering of wire binding element  41  with precise position within the device of the present invention, it is always located in precise position by C-formers  50 ,  50 ′ or O-formers  60 ,  60 ′.  
     [0050] Next, as illustrated in FIG. 11- 5 , first C-former  50  is moved into centering position in the Y-direction. First C-former  50  is located in a centering position if wedge-shaped centering element  53  on base side  41  k of wire binding element  41  is brought into the areas in between the legs of loops S of wire binding element  41 .  
     [0051] The centering, as shown in FIGS.  11 - 6 , is supported by O-formers  60 ,  60 ′ briefly releasing the clamping of wire binding element  41  so that a movement or alignment of wire binding element  41  can be achieved until base side  41   k  of wire binding element  41  comes to rest precisely in the centering element  53  of first C-former  50 , which is provided for this purpose. Then, wire binding element  41  is firmly clamped again by O-formers  60 ,  60 ′.  
     [0052] Then, C-formers  50 ,  50 ′, as shown in FIG. 11- 7  are positioned for bending in that both C-formers  50 ,  50 ′ movie into the insertion position illustrated in FIG. 8 using first C-former  50 .  
     [0053] Consequently, as illustrated in FIG. 11- 8 , C-formers  50 ,  50 ′ are rotated in relation to second C-former  50 ′ into the clamping position of wire binding element  41 , as shown in FIG. 8.  
     [0054] Next, as shown in FIG. 11- 9 , the bending operation of C-formers  50 ,  50 ′ begins by swinging first C-former  50  around fixed pivot point P 1  and second C-former  50 ′ around fixed pivot point P 1 ′ (see FIG. 10). In so doing, wire binding element  41  is over-bent in order to compensate for the elastic spring-back of the wire.  
     [0055] As shown in FIG. 11- 10 , O-formers  60 ,  60 ′ next loosen the clamping of wire binding element  41 , which is henceforth present in C-shape  41   c,  approach bending positions corresponding to pivot points P 2 , P 2 ′ and there, in turn, clamp the wire binding element  41  (see FIG. 11- 11 ). The position of pivot point P 2 , P 2 ′ is in turn dependent on loop length L of the wire binding element and is predetermined by a controller (not shown).  
     [0056] Next, C-formers  50 ,  50 ′ go back into the position shown in FIG. 11- 12 , C-formers  50 ,  50 ′ running through the same curves as in the bending of wire binding element  41 , however, in the opposite direction until wire binding element  41 , which is bent into C-shape  41   c,  is present in the stress-free state. Then, C-formers  50 ,  50 ′ rotate around pivot points P 1  or P 1 ′, in order to release the clamping via clamp flanks  55 ,  55 ′ or tab flanks  56 ,  56 ′.  
     [0057] Next, C-formers  50 ,  50 ′ move out of wire binding element  41  in C-shape  41   c  and into a park position above the comb-threading plane, as shown in FIG. 11- 13 . At the same time, the park position is selected in such a manner that C-formers  50 ,  50 ′ lie outside the movement space of O-formers  60 ,  60 ′ with O-shapes.  
     [0058] After that, O-formers  60 ,  60 ′ bend wire binding element  41 , which is present at that moment in C-shape  41   c,  into a closed O-shape as shown in FIG. 11- 14 . At the same time, as during the C-forming, the wire binding element  41  is over-bent in order to compensate for the spring-back of the wire, so that wire binding element  41  in the stress-free state is in the desired shape.  
     [0059] Next, O-formers  60 ,  60 ′ go back into the position shown in FIG. 11- 15 , O-formers  60 ,  60 ′ passing through the same curves as with the bending of wire binding element  41 , but in the opposite direction, until wire binding element  41 , which is bent into O-shape  41   o,  is in the stress-free state. Then, O-formers  60 ,  60 ′ rotate around pivot points P 2  and P 2 ′, respectively, in order to release the clamping via bending elements  64 ,  64 ′.  
     [0060] Next, O-formers  60 ,  60 ′ first move in the Z-direction into the intermediate spaces between loops S and then in the Y-direction out of wire binding element  41 . Finally, O-formers  60 ,  60 ′ rotate into a horizontal position in order to release access to the now bound booklets  10  (see FIGS.  11 - 16 ).  
     [0061] Finally, the booklets, as shown in FIG. 11- 17 , can be driven out from device of the present invention or manually removed.  
     [0062] As is evident from the description of the method and the movement sequences, C-formers  50 ,  50 ′ or O-formers  60 ,  60 ′ are essentially not a function of loop length L, but only limited by the possibilities for movement on guides provided for this purpose. The adaptation to loop length L of wire binding element  41  is accomplished via the position and movement curves of C-formers  50 ,  50 ′ or O-formers  60 ,  60 ′. The size of tabs  62 ,  62 ′ of O-formers  60 ,  60 ′, which together with the spine must have space inside the wire binding element that is enclosed within O-shape  41   o,  represents a limitation of loop length L below. However, because sheet-form printing materials  11  in booklet  10  also must move in the bound state, this represents practically no technical limitation for the format of a booklet that is to be bound  10 .  
     [0063] By bending the flat, looped wire binding element into a continuous C-shape in the manner of a circular arc, an especially aesthetically pleasing look of the wire binding element may be achieved.  
     [0064] In an advantageous configuration of the device according to the invention, varying loop lengths may be bent without having to undertake a retooling of the device.  
     [0065] Advantageously, the C-formers may have clamp flanks and tabs, these tabs being equipped with a tab flank, tab flank and clamp flank cooperating to clamp the looped wire binding element. In this context the clamping of the looped wire binding element in C-formers may be advantageously created solely by the bending movement of the C-formers. As a result, the surface of the wire is protected, among other things. Moreover, no additional moving parts are required that would necessitate a clamping of the wire binding element.  
     [0066] In a preferred embodiment, the C-formers have centering elements for the centering of the flat, looped wire binding element within the booklet. The flat looped wire binding element is manually inserted or inserted automatically using a wire binding device through holes in the sheet-form printing materials. In order to ensure that the C-formers and the O-formers receive the wire binding element for mounting in such a manner that an optimal aesthetic O-shape may be bent together, it is advantageous if the wire binding element is precisely positioned at the beginning of the bending operation. In accordance with one aspect of the present invention, this is achieved via a series of funnels and centering elements that are assigned to the loops of the wire binding element in the C-formers.  
     [0067] In an advantageous embodiment, the C-formers each have drives for a rotary movement and drives for movement in the X-direction and Y-direction as well as a controller for driving the movement of the C-formers. The controller in this context is advantageous in that it controls the drives of the C-formers when bending the flat looped wire binding element into a C-shape in such a manner that the pivot point of the movement of the two C-formers is within the looped wire binding element. In this way it may be achieved that the torque that clamps the wire binding element during bending and thereby holds it in a fixed position remains constant, and no additional forces arise in the longitudinal direction with respect to the looping direction that would lead to the displacement of the loop within the clamp. This prevents the loop from not being deformed and the wire from being scratched.  
     [0068] In an especially advantageous manner, a flat looped wire binding element can be bent into an O-shape if the movements of the two C-formers during the bending operation run synchronously with each other. In this way additional lateral forces are prevented and the wire binding element in the O-shape becomes rounder.  
     [0069] In an advantageous embodiment of the device according to the invention, the O-formers have tabs running perpendicular to the loop direction of the looped wire binding element, the tabs being shorter than the spacing between two loops of the looped wire binding element. The O-formers are advantageously used to ease the threading of the flat wire binding element in the sheet-form printing materials for stabilizing the printing materials and for that reason are arranged beneath the holes. At a later point in time, namely when the wire binding element is to be further bent into a C-shape, the tabs of the O-formers, which are open on one side, allow the O-formers to dip into the plane of the loop of the wire binding element in order then to grip the loop of the wire binding element by lateral movement.  
     [0070] Advantageously, the O-formers may each have drives for a rotary movement, drives for movement in the X-direction and Y-direction and a controller for driving the movement of the O-formers. In this context, the control of the drives of the O-formers during bending of the flat looped wire binding element into an O-shape may be such that the pivot point of the movement of the two O-formers lies within the looped wire binding element.  
     [0071] Advantageously, the movements of the O-formers during the bending operation may also run synchronously with each other.  
     [0072] In addition, the O-formers may each have a drive for the movement of the O-formers in the Z-direction and control means for control of the movement in the Z-direction. In this way, the above-described operation of the tabs of the O-former dipping into the loop plane may be carried out automatically.  
     [0073] Also the clamping of the -looped wire binding element during O-formation may be advantageously produced solely by the bending movement of the O-formers.  
     [0074] In an especially advantageous embodiment of the device of the present invention, a controller determines speed profiles for the movement of the C-formers and O-formers for different loop lengths of the flat, looped wire binding element, so that a wire binding element is bent together into an O-shape with a corresponding diameter. In so doing, the determination of the speed profiles may include a calculation of the speed profiles with respect to predetermined loop lengths or loop lengths determined via sensor technology. On the other hand, the loop length that is relevant for the movement of the C-forms or O-forms could also be transferred from a device and/or controller that is connected in series or at a higher level. Another possibility is that the speed profiles for the movement of the C-formers or O-formers only have to be stored in and read from reference tables. Advantageously, the speed profiles may be converted into control signals for the drives of the C-formers or O-formers. In this way different loop lengths and, thus, booklets having different thicknesses can be bound using the same tool, namely the C-formers or O-formers of the present invention.  
     [0075] Advantageously, the movement of the C-formers or O-formers may be configured in such a manner that the looped wire binding element is over-bent by the C-formers or O-formers so that the wire binding element is released into the desired shape when relaxed. During the wire bending, the elastic range of the wire must first be overcome in order to achieve a permanent deformation of the wire. Even when there is a permanent deformation, the wire springs back to the elastic range accordingly. In order to obtain a desired bending shape, bending must therefore be carried past the desired shape in accordance with the expected spring-back.  
     [0076] In a preferred embodiment of the device according to the invention, the O-formers are configured in such a manner that, at least for each individual loop of the looped wire binding element, individual bending elements are provided that are fastened to the particular O-former in such a manner as to be replaceable. In so doing, the number of the bending elements per O-former is at least as great as the number of loops that are used for the loose binding of the largest format of sheet-form printing materials that are to be processed. Since the O-formers are parts having relatively complex geometry, the manufacturing effort and, thus, the piece costs can be reduced by division into individual, structurally similar bending elements. Should individual bending elements be damaged, e.g. by the tabs breaking off, this also has the advantage that in this case only the individual bending elements must be changed out, thereby substantially reducing the costs for tool replacement. Alternatively, all bending elements may also be mounted on bars, each of the bars carrying a number of individual bending elements, e.g. 4 or 6. In this embodiment, the bending elements may then be attached to the particular O-formers by bars in such a manner as to be replaceable.  
     [0077] According to another aspect of the concept of the present invention, to achieve the objective a method for the loose binding of booklets that are composed of sheet-form printing materials that in turn are provided with holes is disclosed using at least one looped wire binding element and having the steps:  
     [0078] a) Introduction of the originally flat, looped wire binding element through holes of the sheet-form printing materials,  
     [0079] b) Bending of the flat, looped wire binding element into a continuous arched C-shape using two C-formers,  
     [0080] c) Bending of the looped wire binding element that is in a C-shape into a closed O-shape using two O-formers.  
     [0081] Advantageously, the method may be carried out independently of the loop length of the flat, looped wire binding element.  
     [0082] In an especially advantageous embodiment of the method of the present invention, the bending is simultaneously carried out for all wire loops of a wire binding element for a wire comb binding. The parallel bending of all wire loops of a wire binding element for a wire comb binding substantially accelerates the processing of the wire binding element. Moreover, it may be ensured that all arcs along the wire binding element have the same curved line. As a result, in a complete wire comb binding having a bent wire comb there is an aesthetic exterior and an improved functionality, especially when turning the pages of a booklet having a wire comb binding produced in this manner. It is also within the framework of the method of the present invention to use O-formers or C-formers distributed along the wire binding element with which, for example, only half or a third of all wire loops of a wire binding element are simultaneously bent in order to reduce the forces that emerge in this context. Other subdivisions of bending bars are also conceivable.  
     [0083] Although the invention was described in reference to preferred exemplary embodiments, the invention is not restricted to them, but can undergo changes and adaptations within its area of applicability.