Abstract:
A method for operating a book forming and pressing machine that includes a pressing device and a re-forming device to form a front cut of a book block. Values relating to the book block are determined with a higher order control along a book production line upstream of the book forming and pressing machine. The determined values are transmitted to the pressing device, the re-forming device and/or pressing plates of the pressing device for finishing the book block. A forming tool of the re-forming device is selected based on values that meet operational requirements for the processing of the front cut. The selected forming tool is moved in a plane or space to an operating position for forming the front cut of the respective book block. Movement of the pressing plates is controlled based on the measured book thickness and thickness of the book cover for the book block.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority of Swiss Patent Application No. 00600/12, filed on Apr. 30, 2012, the subject matter of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     The invention relates to a method for operating a book forming and pressing machine which essentially consists of a re-forming device, a pressing device, and a loading device, wherein the loading device essentially is formed by a loading table and wherein the pressing device consists of a number of spaced-apart pressing plates and burn-in rails. The re-forming device is provided with a forming tool to shape or form the front cut on a book block, wherein the pressing device is operated with at least one station for accommodating a book block, and wherein the forming tool executes a series of movements in a plane or in space to form the front cut. 
     Known book forming and pressing machines are used in known book production lines for one of the last finishing steps in book production, meaning for the re-forming of a book block that has already been combined with a book cover. 
     A book forming and pressing machine is disclosed in German patent document DE 4422783 A1, which machine comprises a number of pressing devices with thereon arranged joint-burn-in devices, positioned on a rotor which is driven intermittently around a vertical axis of rotation. The books, which are supplied to a feed-in station of a pressing device that completely accommodates the books, are formed continuously via burn-in rail and are held by the same pressing plate until they are discharged at the discharge station. Between the feeding of the book blocks encased in covers and the discharge of the formed and pressed books, the rotor executes several intermittent rotational movements which are utilized as intervals for the pressing and/or burn-in operations. 
     The German patent document DE 19741755 A1 also discloses a method for setting up a book binding machine, comprising processing stations with servo components which are arranged along the material flow. The problem defined for this document is that the servo components are adjusted with computer control on the basis of specified adjustment variables. With respect to an improvement in the product quality and a shortening of the setup times, the document discloses that the results of individual functions of the process are determined with the aid of data recorders as actual values for a finished product and the resulting variables are then transmitted to a control computer for comparison. Empirical values stored in the control computer are used for adjusting the servo components, wherein the actual value of the finished product is compared in the control computer with the desired value for the finished product, taking into consideration an actual value for the fed-in product which is known to the station and is compared to the empirical values. In case of a deviation from the desired value, the servo components are automatically readjusted. However, one skilled in the art cannot find anywhere in the complete document a teaching describing the steps for a technical action because each operation for a book production is carried significantly by so-called empirical values which are stored in the control computer. This document consequently does not offer instructions to one skilled in the art for recreating the method. 
     Book forming and pressing machines which are known per se thus feed a book with the aid of a loading device into a pressing device and between two pressing plates. The books consist of book blocks encased in book covers and for the most part have a rounded book block back, with the front cut arranged opposite the back. The book block is positioned with its back resting on a loading table in the book forming and pressing machine and is subjected to a re-forming operation. In the process, joints are formed in the book, using burning rails, while the book is positioned in the book forming and pressing machine. The books are held in place between the pressing plates until they are discharged from the book forming and pressing machine. 
     A known re-forming device used for the re-forming operation is provided with a vertically adjustable forming tool, also called a loading punch or a die, which can be lowered onto the front cut. If the burn-in rails are closed only slightly and no pressure or only a slight pressure is exerted with the pressing plates onto the cased-in book block, the book block can be pressed into the back of the cover by lowering the forming tool against the front cut. The back insert and the flyleaf, as well as the two book cover sections, are pressed in a joint against the forming rails, so as to form a joint. With this method, it is important for the quality of the produced books that the forming tool faces the front cut and that its form matches the format of the book to be created. 
     With industrial book production lines, continuously changing book formats and small editions, up to the production of a single book, not only require frequent replacement of these forming tools but also require frequent replacements and more comprehensive adaptations of the book forming and pressing machine on the whole. 
     With the known methods and machines, the loading height for the book is individually adjusted during the loading of a book into the book forming and pressing machine, using a visual inspection, since the form of the book back and the thickness of the back insert influence the position of the book on the loading table, meaning the loading height must be changed. 
     Following the loading operation, a machine operator must take care to ensure that the forming edge has been positioned in a region for the burn-in rail and that the tools which must be replaced in the book forming and pressing machines have been selected to match the form of the book. According to the prior art, these forming tools are adjusted by sight. 
     A method of this type no longer meets the current order situation for an industrial book production line. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to remedy this problem. 
     It is another object of the invention to ensure a flexible adaptation of the elements used in the book forming and pressing machine when using a method of the aforementioned type, so as to meet the requirements posed by differences in the formats, consistency and configuration of the books to be produced, as well as to move these elements to the operating position without manual intervention. 
     It is yet another object of the invention to use a book forming and pressing machine of the generic type with the goal of controlling as many of the connected work stations as possible with an automatic format adjustment, designed to avoid a replacement of parts or utilize a motorized adjustment with the aid of information relating to forming values, generated in the upstream-arranged machine, e.g. the rounding height, the rounding width, the rounding radius, the joint edge, wherein these values are then transmitted continuously by the control unit to the book forming and pressing machine. 
     The above and other objects are accomplished according to the invention, which in one embodiment provides for a method for operating a book forming and pressing machine including a re-forming device, a pressing device and a loading device, wherein the loading device includes a loading table and the pressing device includes a number of spaced-apart pressing plates and burn-in rails, wherein the re-forming device includes a plurality of forming tools adapted to form a front cut of a book block, and the pressing device includes at least one station to accommodate a book block, the method comprising: executing a series of movements by one of the forming tools in a plane or in space to form the front cut, the executing step including: determining values relating to the book block, including a measured book thickness and a thickness of a book cover, with a higher order control unit along a book production line arranged upstream of the book forming and pressing machine; transmitting the determined values at least to one of the pressing device, the re-forming device and the pressing plates for finishing the book block; selecting one of the forming tools of the re-forming device based on the values that meets operational requirements for the processing of the front cut; and moving the forming tool to an operating position for forming the front cut of the respective book block; and controlling a movement sequence of the pressing plates based on the measured book thickness and thickness of the book cover for the book block. 
     Thus, according to the invention, a higher order control unit accepts the transfer of values determined along the preceding book production line and continuously transmits these values to the control unit for the book forming and pressing machine which then selects the forming tools for the book forming and pressing machine based on these values, as well as the traversing distances and the required power for the drive units. 
     If necessary, the values determined along the upstream-arranged book production line may be used for the format adjustment of the discharge station at the book forming and pressing machine or at different, downstream-connected machines. 
     The re-forming device comprises at least one tool carrier equipped with at least one component embodied as a shaping or forming tool for forming the front cut. The tool carrier or the tool may execute a sequence of movements in a plane or in space, relative to the front cut to be formed, wherein the sequence of movements can be machine adjusted, freely programmable or can optionally be guided by at least one sensor. 
     The higher order control unit which determines values relating to the book block along the book production line is arranged upstream of the book forming and pressing machine to ensure these values are transmitted to at least the pressing device and/or the re-forming device and/or the pressing plates for the finishing operation of the book block, such that based on the values determined along the book production line prior to the finishing step for the book block, at least the forming tool which meets the forming requirement is selected the operation, that the selected forming tool for the upcoming processing of the respective book block is then moved to the operating position, and that the kinematic force of the pressing plates is controlled during the course of the re-forming operation on the basis of the values for the measured total thickness and the thickness of the book cover for the book block. 
     In the loading station, the books are moved along successively, or if need be while divided into at least two book flows, and are put into an upright position with the aid of a loading rake with thereto assigned guide web, so that they can subsequently be transported from a loading table provided with prism strips from below into the opened, stopped pressing device while supported on the side by the loading rake and a counter rake. Separate inserts are available for the prism strips to accommodate books having either a rounded or a flat back. 
     With only slightly closed burn-in rails and pressing plates that are closed with or without pressure, a forming tool of the re-forming device is lowered against the front cut and presses the book block against the back of the cover, thereby causing the two book cover sections to be pulled via the insert and the flyleaf in the joint against the burn-in rails. The book block and the book cover can thus be oriented relative to each other at the same time as the re-forming of the book takes place. The forming tools include separate inserts for the forming of books with a rounded back and a flat back. 
     With specific configurations of the front cut, it is also possible to use a series of sequentially operated forming tools which gradually form the final shape of the front cut. 
     An additional feature of this machine is that the operator can input the main dimensions for the book at the operating panel for the machine, or these dimensions can be read out of the job definition format database (JDF), or they can be measured at the preceding machine. The width, height and thickness of a book block trimmed along 3 sides are determined for this in a measuring device while the dimensions of the book cover are measured as well. These values describe the book block which is loaded into the rounding and casing-in machine, arranged upstream of the book forming and pressing machine, but they do not describe the book block which finally leaves this upstream-arranged machine. The book block is rounded and pressed in the upstream-arranged machine, is optionally provided with gauze paper that is glued on and, depending on the embodiment, is provided with a glued-on headband, and the book cover is pre-formed in the back region. Depending on how these processing steps take form, a specialized book form is obtained with respect to the book back and the joint edge once the book block and the book cover are joined. 
     When inserting a book between the two pressing plates of the book forming and pressing machine, the loading height of the book is adjusted since the form of the rounded book back and the thickness of the back insert influence the position of the book on the prism strips, thus changing the loading height as a consequence. 
     The loading height is furthermore individually adjusted as a result of the position of the joint edge since this edge is located in the region of the burn-in rail following the loading operation. The forming inserts of the re-forming station are also selected based on the rounding for the book back and the path traversed by the forming tool is preset automatically. 
     As soon as the last book of an order has exited from the loading station for the book forming and pressing machine and is held in place in a pressing device, the loading station which is provided with a separate drive can be adjusted for a new book format. For the automatic adjustment of the lift for loading the book into the ready, opened pressing device, the form of the rounded book block and the form of the rounded book cover, as well as the rounding radius for the book cover and for the book block or the position of the book joint must be known to the machine control unit in addition to the book thickness, the book height and the book width. 
     Since these values are generated in the upstream-arranged machine, or are used therein as setting values for applying glue over the complete book block surface and for precisely encasing the book block in the cover, these data only need to be transmitted from there to the control unit for the book forming and pressing machine. 
     The correct position of the prism strips and the required loading height are then computed with the aid of these values. The adjusted loading position is correct if the burn-in rails hit the intended location in the joint of the inserted book block during the closing of the pressing device. 
     If the book block is additionally formed with the aid of the forming tool that can be advanced, the geometry of the formed book block is required for the automatic selection of forming inserts. Also required is a precise image of the book block encased in the cover, so that the forming tool can impact softly with the front cut during the forming of the book block and can press the book block with its back region into the rounded book cover, wherein for this the two book cover sections are pulled via the back insert and the flyleaf in the joint against the burn-in rails. The required traversing distance for the forming tool is computed from the selection of forming inserts, the achieved rounding result at the book cover and the book block, as well as the position of the joint edge on the book cover. The book block and the book cover can thus be automatically oriented relative to each other while the book block is simultaneously formed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features and advantages of the invention will be further understood from the following detailed description of the embodiments with reference to the accompanying drawings. 
         FIG. 1  is a schematic representation, designed to illustrate a data transfer between a book production line and a book forming and pressing machine; 
         FIG. 2  is a flow chart for illustrating the signal flows around a control unit for the book production line, around a control unit for the book forming and pressing machine, and between these control units; 
         FIG. 3  is a further schematic representation, similar to the one in  FIG. 1 , showing the left side of a book production line for illustrating the detection of settings used in the book production line when processing an 80 mm thick book; 
         FIG. 4  is another schematic representation, referring to  FIG. 1 , showing the right side of the book forming and pressing machine for illustrating the computing of setting for relevant components of the book forming and pressing machine, using the example of the 80 mm thick book shown in  FIG. 3 ; 
         FIG. 5  a representation analogous to  FIG. 3 , with a 20 mm thick book; and 
         FIG. 6  a representation analogous to  FIG. 4 , with the pointed burn-in rail and the thin book from  FIG. 5 , measuring 20 mm. 
     
    
    
     DETAILED DESCRIPTION 
     The method according to the invention for controlling a book forming and pressing machine  20  is illustrated in  FIGS. 1 to 6 . 
     These Figures contain specific dimension values that are operatively linked to the control unit and, within the meaning of a complete disclosure of the content, show the concrete steps of detecting, introducing and processing of the corrections values. 
       FIG. 1  schematically shows a transfer  1  of data from an upstream arranged machine in a book production line  10  to the book forming and pressing machine  20 . With a method realized in a book production line  10  that is arranged upstream of the book forming and pressing machine  20  and is shown to the left of a vertical dash-dot line, a book block  30  is initially arranged without book cover  18  on a transport element  16 , a so-called saddle plate. The back of the book block  30 , which is formed to correspond to the later book back  37 , faces upward in that case. Given this orientation, the book block  30  has a block width  32  in the vertical direction and a book thickness  34  in the horizontal direction. An open front cut  38  is positioned opposite the closed book back  37 . With the aid of a glue roller  12 , glue is applied to the two outside areas of the book block  30 , starting at the joint edge  123 . 
     Following this, the glue-covered book block  30  is combined with a book cover  18 . With the aid of a pressing-on device  14 , for example in the form of two pressing-on rollers, the supplied book cover  18  is oriented relative to the book block  30  and is secured in place, so that the rounding  31  of the book cover  18  fits precisely over the book back  37 . The measured distance between the contact surface of the pressing-on rollers of the pressing-on device  14  on the book cover  18  and the joint edge  123  can be called up as a setting  11  for the pressing-on device  14 . 
     Glue is applied in the process to the complete surfaces of the book block  30  positioned on the saddle plate, that is during the upward movement between two glue rollers  12 , and the book block back comes in contact with the pre-formed insert for the book cover arranged above in a horizontal position. The pressing-on rollers of the pressing-on device  14  push the insert of the book cover  18  against the book block back and the pressing-on device  14  then moves synchronously along with the book block  30  on the saddle plate. During the upward movement, the two halves of the book cover  18  are folded down and fit themselves against the glue-covered surfaces of the book block  30 . As soon as the two halves fit completely against the book block  30 , the pressing-on device  14  moves downward, the pressing on rollers are pushed apart somewhat by the mushroom form of the book back  37  and return with spring force to press the book cover  18  against the glue-covered book block  30 . As a result, the pressing-on rollers of the pressing-on device  14  execute a controlled, vertical movement and a spring-loaded, small horizontal movement. 
     The following data are thus known as input values  2  before the inventive method is realized by the book forming and pressing machine  20 : the book width  32 , the book thickness  34  and an insert thickness  36  of the book cover  18 . The computed values  3  of the book production line  10  are the values for the distance  23  between a top of the book block back and the joint edge  123  and the pressing-on device setting  11 . The data transfer is furthermore illustrated in  FIG. 2 . 
     According to  FIGS. 1 and 2 , the computed values  3  of the book production line  10  for the distance  23  between a top of the book block back and the joint edge  123  and the setting  11  for the pressing-on device  14 , and the input values  2  for the book format are transferred via a data transfer  1  to the control unit for the book forming and pressing machine  20 . 
     The flow chart shown in  FIG. 1 , to the right of the dash-dot line, shows a standard arrangement of the book block  30 , with the book back  37  facing downward, in the book forming and pressing machine  20 . Pressing plates  28  press the book cover  18  from the left side and the right side against the book block  30  so that it fits flat against the book block  30  (only the left pressing plate  28  is shown herein). The book rests with its book back  37  on a loading table  27  which can be adjusted in height by a loading table setting  21 . 
     A standard configuration of the loading table  27  consists of two prism plates which are arranged parallel to each other (only a section of the left prism plate is indicated herein). The book back  37  makes contact with these prism plates along at least two contact lines. Below the pressing plates  28  and above the loading table  27 , a pointed burn-in rail  24  can be moved from both sides (only the left side is shown herein) in the region of the joint edge  23  against the book cover  18  and the book block  30 . 
     The burn-in rail  24  point, which faces the book, determines a horizontal zero line  29  as one of several options, based on which the settings  21 ,  26  of the book forming and pressing device  20  are adjusted. 
     The book forming and pressing machine  20  furthermore comprises a forming tool  22  as a component of a re-forming device. The forming tool  22  can be lowered by the value for the forming tool setting  26  from above onto the front cut  38 . The forming tool is arranged on a tool carrier, not shown in further detail, and executes a series of movements in a plane or in space for the forming of the front cut  38 , wherein the sequence of movements is machine controlled, freely programmable, or can optionally be guided by at least one sensor that is not shown herein. Such a sensor continuously detects directly or indirectly at least one information relating to the position of one or several forming tools  22  of the re-forming device in a movement plane or in space, or it detects the position of the operatively specified forming tool  22  and transmits this information relating to the position and/or transmits the position itself to the control unit. 
     According to the inventive method, the loading table  27  of the book forming and pressing machine  20  must first be moved to the correct height, meaning to the loading table setting  21  as a first computed value  4  for the book forming and pressing machine  20 . For this, the loading table  27  can be operated with a non-depicted displacement sensor. According to a first embodiment of the inventive method and using a burn-in rail  24  with the tip positioned at the level of the zero line  29 , the pressing-on device setting  11  is used as the loading table setting  21 . 
     In the first exemplary embodiment, the setting values  21 ,  26  in  FIGS. 5 and 6  are computed to correspond to a thin book of 20 mm. 
     The loading table setting  21 , as computed value  4  for the book forming and pressing machine  20 , is equal to the setting  11  for the pressing-on device  14  as computed value  3  for the book production line  10 . 
     According to one embodiment of the inventive method, the value for the book thickness  34  is incorporated into the computation for the pressing-on device setting  11 , which is obvious when comparing  FIGS. 3 and 5 . 
     The forming tool setting  26  as computed value  4  for the book forming and pressing machine  20  is equal to a difference obtained when deducting the distance  23  between a top of the book block back and the joint edge  123  as computed book production line value  3  from the block width  32  as input value  2 . 
     According to a second embodiment of the inventive method, an upper edge of a blunt burn-in rail  24 ′ ( FIG. 4 ) determines the zero line  29  (see  FIGS. 3 and 4 ) in place of the tip of the burn-in rail  24 , as shown in  FIGS. 1 ,  5  and  6 . 
     The loading table setting  21  and the forming tool setting  26  are converted by the control unit for the book forming and pressing machine  20  in the same way as for the first embodiment, relative to the zero line  29 , by activating fast actuators, for example linear servo motors, which are not shown further herein, for the loading table  27  and the forming tool  22 . 
     According to the second embodiment shown in  FIGS. 3 and 4 , the loading table setting  21  as computed value  4  for the book forming and pressing machine  20  is equal to the sum of the setting  11  for the pressing-on device  14  as computed value  3  for the book production line  20  and a correction setting  25  for the burn-in rail  24 , which is correspondingly taken into consideration as tool correction setting  5  for the obtuse burn-in rail  24 ′. 
     According to the second embodiment and/or the  FIGS. 3 and 4 , the forming tool setting  26  as computed book forming and pressing machine value  4  is equal to a difference between the block width  32  as input value  2  minus the distance  23  between a top of the book block back and the joint edge  123  as computed book production line value  3  and minus the correction setting for the burn-in rail  25  as tool correction setting  5 . 
     Based on a further advantageous embodiment of the invention, which is not shown in detail in the schematic representation according to  FIG. 1 , an adjustment of the prism plates on an adjustable loading table  27  is taken into consideration when computing the settings  21 ,  26  as further tool correction setting  5 . 
     According to yet another advantageous embodiment of the inventive method, a replacement forming tool  22  is furthermore taken into consideration as a tool correction setting  5 , in particular when computing the forming tool setting  26 . 
     The following qualitative dependencies can be recognized when operating such a book forming and pressing machine:
         a) The joint edge and the setting for the pressing-on device are computed in the book production line.   b) The height of the prism table is a function of the pressing-on device setting and the form of the burn-in rail (width of burn-in joint), wherein it should be taken into account that the back insert thickness has already been considered in the setting for the pressing-on device, wherein in  FIGS. 5 and 6  the height of the prism table, put in a simplified manner, corresponds to the pressing-on device setting.       

     It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.