Abstract:
A production line including a casing-in machine and a processing section upstream of the casing-in machine. The processing section includes processing stations arranged at clocking intervals along the processing section to process a book block spine. The processing section includes a first processing station group and a second processing station group. The production line further includes a conveyor to successively supply the book blocks in clocked operation to the processing stations. The conveyor includes a first conveying section assigned to the first processing station group, the first conveying section including a first individual drive, and a second conveying section assigned to the second processing station group, the second conveying section including a second individual drive. The production line further includes a control unit operatively connected to the first individual drive and second individual drive to change the clocking interval length along the processing section.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority of the European Patent Application No. 09405097.8, filed on Jun. 5, 2009, the subject matter of which is incorporated herein by reference. 
     BACKGROUND 
     The invention relates to a production line for producing books comprising a book casing and a therein encased book block. The production line comprises a casing-in machine arranged at the conveying end of the production line, used for encasing a book block inside a book casing, and a processing section. The processing section comprises additional processing stations with processing devices assigned at partial distances or clocking intervals along the processing section. A book block can be advanced along the processing stations of the processing section for processing a book block spine. The processing stations comprise, in the conveying direction of the book blocks, a feed station for supplying the processing section with book blocks, a takeover station for taking over the book blocks, an adhesive-application station for spreading adhesive onto the book block spines, a backing station for attaching a backing strip and, if applicable, at least one headband, as well as a pressing station for pressing the backing strip or a headband against the book block spine, all arranged in the above sequence. The book blocks can be supplied successively and in a clocked manner to the processing stations with the aid of a conveyor and with the spines facing the processing devices. 
     For structural and arrangement reasons, the partial distances, also called the clocking intervals, between the processing stations are normally uniform along a conveying section for the takeover station, the following adhesive application station and the backing or headband-application station, but are farther apart by approximately 40 mm than the regular partial distances or clocking intervals for the conveying section assigned to the feed station. 
     Book production lines of this type are disclosed, among other things, in German patent document 43 34 224 A1, German patent document 43 34 225 A1, Swiss patent document 694 016 A5 and European patent document 1 894 739 A1. 
     With the disclosed book production lines, the conveying device and the processing stations are connected to a central drive motor. This arrangement requires a high driving power and results in high mass moments of inertia leading to the use of heavy gears and other involved drive elements. In recent years, the market for printed products, especially books, has shifted to extremely small editions of short-run productions for which the use of individual drives with angle of rotation controlled motors is suitable. Among other things, these motors offer the advantage that complete conveying sections can be stopped in case of a malfunction or that only the remaining production run can be processed out. Book blocks which are located downstream of the malfunction location on the production line can be processed further, meaning the portion of the production line that follows the malfunction can be emptied. As a result, waste material is noticeably reduced for very small editions, thus advantageously impacting the costs. 
     A traditional book production line normally comprises three conveying sections along a conveying line. The first conveying section is a feed or transfer section in which the book blocks are conveyed in a clocked manner, aligned and then transferred to the second conveying section for additional processing stations that follow in the downstream direction. 
     The second conveying section provides additional processing stations, as seen in the conveying direction, with a takeover station in which the book blocks are respectively positioned with the aid of a device on the feed section before being picked up by the movable chain mouth of side-by-side circulating chain conveyors that form the additional conveying section for the additional processing stations. The adhesive-application station, the backing station and the pressing station are located along this conveying section, as seen in conveying direction, wherein the adhesive is applied while a book block is moving through and after it is picked up by the chain conveyor, and wherein the subsequent backing and pressing operations occur successively while the book block is stopped. 
     The third conveying section is formed by the casing-in machine, in which six conveying elements circulate, for example in the form of a bucket conveyor. 
     The processing of small editions, for example involving 1 to 20 copies of book blocks of the same thickness, requires a relatively high share of the total expenditure for the set-up or conversion time. With traditional, standard book production lines, the requirements for producing a single-book edition can only be realized with difficulty and at high cost. 
     SUMMARY 
     It is an object of the present invention to create a book production line that makes possible a considerable improvement in the efficiency of the book production line when processing small editions of books having different thicknesses. 
     The above and other objects are accomplished according to one aspect of the invention wherein there is provided a production line for producing books including a book casing and a therein encased book block which, in one embodiment, includes a casing-in machine, arranged at a conveying end of the production line, to encase a book block in a book casing. The production line further includes a processing section upstream of the casing-in machine. The processing section includes processing stations arranged at clocking intervals along the processing section to process a book block spine. The processing stations include processing devices. The processing section includes, in sequence of the conveying direction of the book blocks, a first processing station group. The first processing station includes a feed station to supply book blocks to the processing section. The processing section further includes a second processing station group including, in sequence of a conveying direction of the book blocks, a transfer station to take over the book blocks, an adhesive-application station to apply adhesive to the book block spines, a backing station to attach a backing strip, and a pressing station to press the backing strip against the book block spine. The production line further includes a conveyor to successively supply the book blocks in clocked operation to the processing stations with the book block spines exposed and pointing upward toward the processing devices. The conveyor includes a first conveying section assigned to the first processing station group, the first conveying section including a first individual drive. The conveyor further includes a second conveying section assigned to the second processing station group, the second conveying section including a second individual drive. The production line further includes a control unit operatively connected to the first individual drive and second individual drive to change the clocking interval length along the processing section. 
     As a result, the length of the clocking intervals can be changed along the conveying section assigned to the processing stations. 
     A conveyor for the casing-in machine may be synchronously driven with the clocking rate of at least one of the conveying section for the feed station or the conveying section for the processing stations in order to coordinate the book production line. 
     The clocking interval length along the conveying section between the processing stations may be adjustable or re-adjustable to multiple lengths to achieve a higher performance efficiency. 
     With the herein described book production line, the clocking interval can be adjusted or re-adjusted to twice the length along the conveying section assigned to the processing stations, thereby avoiding any change in the coordination of the conveying sections. 
     Of course, it makes sense if the conveying sections for the processing stations and the feed station in which the book blocks are integrated into the process have approximately the same or different clocking interval lengths for large as well as small editions. 
     For the sake of simplicity, a multiple-length clocking interval on the conveying section assigned to the processing stations can be triggered via the control unit, based on a specific circulation number of uniformly thick book blocks. 
     The control unit may therefore be connected to a program and data memory for controlling the course of the processing of one or a plurality of successively following book block editions. 
     A change in the clocking interval length along the conveying section assigned to the processing stations to a clocking interval several times longer may occur for small editions ranging from one to five hundred book blocks so performance efficiency is improved. 
     The conveying section assigned to the processing stations of the processing section, arranged upstream of the casing-in machine as seen in book block conveying direction, may comprise alternately arranged processing stations designed for processing book blocks which are stopped or processing stations for processing book blocks that are moving through, to achieve a higher performance efficiency. 
     The end of the conveying section that is assigned to the processing stations in conveying direction of the book blocks, may therefore be a processing station which takes over the book blocks while the book blocks are stopped. The processing stations may then achieve a favorable clocking interval arrangement with an uneven clocking interval length between the conveying sections. 
     The book production line may be embodied so the conveying section that is assigned to the processing stations can be adjusted or re-adjusted during the processing of the book blocks. 
     It has proven useful if the individual drives for the conveying sections assigned to the processing stations and the feed station, respectively the casing-in machine, are provided with angle of rotation controlled electric motors, also called servo motors, which are operatively connected to the control unit, thus also resulting in an efficient structural design. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be more readily understood from the following detailed description when read in conjunction with the accompanying drawings, in which: 
         FIG. 1  A perspective view of a schematically shown book production line for the processing book blocks at clocked intervals along a processing section which ends in a casing-in machine; and 
         FIG. 2  The book production line according to  FIG. 1  with multiple clocked interval processing along the processing section. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  schematically shows a book production line  1  for producing books  4  comprising a book casing and a therein encased book block  3 . The conveying end of the book production line  1  is formed by a processing station which is also referred to as casing-in machine  5  and is described, for example, in European patent documents 1 780 037 A1 and 1 780 038 A1, as well as in the German patent document 19729529, the disclosures of which are incorporated herein by reference. 
     The casing-in machine  5  is used for applying adhesive to the outside surfaces of the book block  3  and for pressing a book casing  2  against the adhesive-coated outside surfaces of a book block  3 . For this, the casing-in machine is provided with a bucket-type conveyor  6 , having a traction device that circulates in a vertical plane and thereto attached, jib-like extending saddle plates  8  for holding and transporting the book blocks  3  which are supplied by the processing section  20 . 
       FIG. 1  furthermore shows the instantaneous position of six saddle plates  8  along the illustrated movement path where they have a nearly horizontal upper edge for accommodating the book blocks  3 . The book blocks  3  are moved in the conveying direction F of the book blocks  3  along the processing section  20  and over a block divider (not shown herein) with the opened front, also called the fore edge, pointing downward. The block divider spreads out each book block  3  in the center so the book block  3  is in a position for takeover by the conveyor  6  in which the saddle plates  8  take over the book blocks by dipping from below into the slightly spread-out book blocks  3 . 
     Following this, each book block  3  now straddling the saddle plates  8  moves vertically upward through an adhesive-application device, not shown herein, in which a book casing  2  supplied on the side of a pressing device (not visible herein) is pressed against the adhesive-coated outside surfaces of a book block  3 , also called the fly leaves of a book block  3 . Further along the conveying path of the casing-in machine  5 , the just produced books  4  reach a delivery station  9  where they are taken over by a delivery element  10  and are deposited on a delivery belt, not shown herein. 
     Arranged upstream of the casing-in machine  5  is a processing section  20 , along which additional processing stations are arranged at regular partial distances, also called clocking interval lengths. The processing stations include processing devices for processing a book block spine  21 . As seen in conveying direction F for the book blocks  3 , a feed station  13  with a feeding device  14  for supplying the following processing station is arranged at the start of the processing section  20 . 
     The clocked feeding of the book blocks  3  is realized, for example as shown in  FIGS. 1 and 2 , with the aid of a star rotor  15  driven around an axis extending parallel to the conveying direction F at the clocking rate of the conveying section  16  for the feed station  13 . The star rotor  15  is provided along the circumference with six holding compartments for respectively supplying one book block  3  with its fore edge leading. The star rotor  15  deposits the book block  3  respectively with the fore edge onto a guide surface (not shown herein) where it is transported in synchronization with the clocking rate of the processing section  20  by a finger. The finger acts upon the rear edge of the book block and is positioned on a conveying chain (not visible) that is assigned to the feed station  13 , respectively a feed device  14 . The feed station  13 , respectively the feed device  14 , forms a separate feed section  16  which advances by several clocking intervals for transferring the book blocks  3  to the following processing station, a takeover station  17  of a conveying section  18  of the processing section  20 , which follows in conveying direction F of the book blocks  3 . 
     The separate conveying sections  16 ,  18  are provided with separate drives  22 ,  23  which are operatively connected to a joint control unit  24 . The individual drives  22 ,  23  can be embodied as geared motors with an angle of rotation controlled electric motor and can be controlled individually or separately by the control unit  24 . That is to say, the conveying sections  16 ,  18  can be operated with differently long clocking intervals. For the matter at hand, the conveying section  18 , arranged downstream of the conveying section  16  for the feed station  13 , as seen in conveying direction F of the book block  3 , can be adjusted or re-adjusted to clocking intervals which are multiple times, for example two times, longer than is provided between the processing stations. A slight difference in the clocking interval length between the conveying sections  16  and  18 , for example a clocking interval length that is longer by 40 mm in the conveying section  18  as compared to the conveying section  16 , does not impact the functions or movements of the processing section  20 . 
     To synchronize the clocking intervals over the complete book processing line  1 , it may be useful if the conveyor  6  that is assigned to the casing-in machine  5  is synchronously operated with the clocked conveying speed of one of the two or both conveying sections  16 ,  18 . The transfer of the book blocks  3  from the conveying section  16  to the conveying section  18  can be realized, for example, with a conveying clamp  19  as described in European patent document 09405082.0, the disclosure of which is incorporated herein by reference, which transfers the book block  3  over two clocking intervals to the conveying section  18 . The conveying section  18 , which is distinguished by the processing of a book block spine  21 , is provided at the front end as seen in conveying direction F of the book blocks  3 , respectively at the intake for the conveying section  18 , with the aforementioned takeover station  17  in which the book blocks  3  are initially stopped until they are gripped on the conveying section  18 . 
     This downstream arranged conveying section  18  of the conveyor assigned to the processing section  20  is formed by two conveying belt sections  25 ,  26 , arranged on the side at a uniform distance to the longitudinal center axis that extends through the longitudinal center plane for the upright standing books blocks  3 , of two adjacent and synchronously circulating conveying belts or conveying chains  27 ,  28 , wherein the conveying belts  27 ,  28  are driven around the approximately vertical axes of deflection rollers that are not visible herein. 
     The intake region  29  of the conveying section  18 , which is arranged upstream in conveying direction, projects counter to the conveying direction F over the transfer position for the conveying clamp  19 , respectively the clamping jaws  30 ,  31  which form the conveying clamp, thus resulting in a super imposition of the conveying sections  16 ,  18 . The intake region  29  forms a chain mouth  34  which is opened when a book block  3  is supplied with the aid of the conveying clamp  19  that is mounted on a sled or carriage. For this, the intake region  29  is expanded in a V shape to narrow down in a wedge-shaped taper in conveying direction F, thus ensuring a careful takeover of the book blocks  3  by the conveying section  18 . 
     The opening and closing of the chain mouth  34  is achieved by pivoting to the side around vertical axes  35 ,  36  of the end sections  32 ,  33  that form the intake region of the conveying belts  27 ,  28 , wherein the empty belt sections of the conveyor belts  27 ,  28  fit flush against side-mounted support rollers  37 ,  38 . To change the conveying gap between the conveying belt sections or the working belt sections of the conveying belts  27 ,  28  for adapting these to the thickness of the book blocks, the latter can be adjusted or readjusted uniformly with respect to the mutual spacing. 
     The takeover station  17  is followed in conveying direction F of the book blocks  3 , advanced by one clocking interval, by an adhesive application station  39  which is indicated by an adhesive roller  40 . The latter is driven to roll off the book block spine  21  for applying the adhesive, such that the book block  3  passes through the adhesive application station  39  without stopping and is stopped only after the next clocking interval in the backing station  41 , in which a backing material strip  43  is supplied from a roll  42  to the adhesive-coated book block spine  21 . Following two more clocking intervals in conveying direction F, a pressing station  44  is arranged on the processing section  20  in which the backing material  43 , placed onto the book block spine  21 , is pressed against the adhesive-coated book block spine. The book blocks  3  reach the casing-in machine  5 , respectively an available saddle plate  8 , over the course of two or four clocking intervals following the pressing station  44 . The conveying sections  16 ,  18 , which function as a conveying device for the processing section  20 , are driven separately with the aid of individual drives  22 ,  23  that are provided with angle of rotation controlled electric motors. The conveyor  6  of the casing-in machine  5  is also advantageously provided with a separate drive  45  which operates synchronized with the clocking rate of the at least one or both individual drives  22 ,  23  for the conveying sections  16 ,  18  via the joint control unit  24 . 
       FIG. 2  shows the book production line  1  during the processing of book blocks  3 , using a double clocking interval in conveying direction F between two processing stations  17 ,  41 ,  44 ,  5  in which a book block spine  21  is processed while the book block  3  is stopped. In particular small and extremely small editions make it possible to move with multiple or double clocking intervals along the conveying section  18  (as shown in the embodiment) over the processing section  20 . 
     One difference lies in the manner in which the processing stations are arranged along the conveying section  18 . An idle stroke step  46  may be provided between the backing station  41  and the pressing station  44  to obtain a double clocking interval along the conveying section  18 , respectively a double stroke length for the clocking strokes. 
     With large editions, the resulting gap can be closed during normal operations by moving the pressing station  44  to be positioned downstream of the backing station  41 , for example by having a mobile station, thereby closing the gap once more. The adhesive-application station  39  does not present an obstacle for a double clocking interval since adhesive is applied to the spine  21  of a book block while it is passing through. 
     It is 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.