Abstract:
A conveyance device for the pressing of glued spines of a book block for books, in which the book blocks, with their spines directed downward, pass through a pressing section that reduces the spine swell. The book blocks, gripped between working pieces of revolving traction elements, pass through the pressing section, which acts on the sidepieces of the book spine.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a device for conveying book blocks on a conveying line of a machine for producing books, magazines, or the like, along which conveying line a revolving conveying element is installed, which conveys the book blocks and is designed with finger-like pushers that are mounted on a traction mechanism and project into a conveying channel transversely to the conveying direction. 
   2. Description of the Related Art 
   Devices of the aforementioned type are known, for example, in installations for producing perfect-bound book blocks or books and in back-gluing machines, especially for thread-stitched book blocks. 
   In gathering machines, to form loose book blocks by feeders arranged along a conveying line, a conveying channel is loaded with printed products, and the book blocks, which are formed from stacked printed products are fed, standing on the spine of the book block, to a perfect binder. On the conveyance path, the loose book blocks are set up vertically, so that they can be inserted from below into the revolving conveyor clamps of a perfect binder. For this purpose, the gathering machine has pushers, which are mounted on a traction mechanism and project into a conveying channel and, during the formation of the loose book blocks, convey the latter by pushing against the so-called head or foot edge of the book block. During this process, the book block is turned about 90° in a vertical plane transverse to the direction of conveyance by a setting up element, so that it arrives at the perfect binder standing on its spine. In this conveyor section, the book block passes the setting up element, which is winding more or less helically in the conveying direction, where the book block is set on its spine, and the pusher is successively shifted into a horizontal position by a guide slot. 
   Both during the gathering of the printed products and during the transfer from the gathering machine to the perfect binder, it happens that printed products collide on the conveying tract and are displaced relative to the conveying direction, so that a backup then develops, which can cause the pusher, which is made of plastic, to break. Furthermore, in addition to the breaking of the pusher finger, the hinge, the holder, and/or chain links of the traction mechanism are damaged and thus must be replaced. This results in increased repair expense, especially since there are only “a few” places along the conveying line at which there is enough room to be able to repair the damage. 
   If the damage involves the chain, the tension on it must be released to replace the links. Accessibility to the chain with tools is limited in most cases, and it is no simple matter for the repairman to do his job properly in tight spaces with screws, nuts, bolts, and lock rings. 
   SUMMARY OF THE INVENTION 
   Therefore, it is the primary object of the invention is to construct the pushers and their mounting parts in such a way that disassembly or exchange of parts can be carried out simply without strain on the traction mechanism and without spending a great deal of time. 
   In accordance with the invention, this object is achieved in such a way that the finger-like pusher has a predetermined breaking zone located some distance from the mounting point; so that when the pusher breaks, no other parts of the conveying element are damaged. 

   
     BRIEF DESCRIPTION OF THE DRAWING 
     In the drawing: 
       FIG. 1  shows a partial three-dimensional representation of a conveying channel of a gathering machine. 
       FIG. 2  shows a partial three-dimensional representation of the conveying channel after a setting up element. 
       FIG. 3  shows a partial top view of a conveying element, which comprises a traction mechanism and a pusher mounted on it. 
       FIG. 4  shows a cross section along line IV-IV in  FIG. 3  through a predetermined breaking zone of the pusher. 
       FIG. 5  shows a cross section along line V-V in  FIG. 3  through the pusher. 
       FIG. 6  shows a partial longitudinal section in the conveying direction through the conveying element. 
       FIG. 7  schematically shows feeders used in the device according to the invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  shows a section of a conveying channel  1  of a gathering machine, in which a loose book block  3  consisting of gathered signatures  2  is located. The book block  3  is conveyed at its back end (relative to the conveying direction F) by a pusher  5  mounted on a driven conveying chain that is used as the traction mechanism  4 . The conveying channel  1  has a guide wall  6 , which the signatures  2  strike fold first as they are fed individually from the opposite side by signature feeders  43 . The pushers  5 , which are mounted at regular intervals on the revolving conveying chain, run in a slot  7  in the base  8  of the channel and serve to convey the forming book block  3 . 
   At the end of the gathering line, the conveying channel  1  turns about 90° in the conveying direction, so that the book block  3  is standing on the folded spines of the signatures  2  and is further conveyed by the pusher  5 , which has also turned 90°.  FIG. 2  illustrates the book block standing on its spine, which is formed by the edges of the signatures  2 . The pusher  5  passes through two lateral guide walls  9 ,  10  that form the conveying channel  1 . The guide walls are provided with slot-like recesses  11 ,  12 . 
     FIG. 3  shows the pusher  5  in the position illustrated in  FIG. 2 , in which a multilink, simple roller chain is provided as the traction mechanism  4 . The roller chain consists of inside links  13  and outside links  14 , whose plates  15 ,  16  are securely connected by bolts  17  and sleeves  18 . Freely rotating, hollow rollers  19  are supported on the sleeves  18 . 
   At the mounting point of the pusher  5 , for which an outside link  14  is used, an outside plate  16  is replaced by a bearing block  20 , which serves as the mounting for the pusher  5 . For this purpose, the bearing block  20  is provided with a mounting plate  21 , in which two bolts  17  of the outside link  14  are riveted at one end with the mounting plate  21  of the bearing block  20  and are releasably secured at the other end by a spring shackle  22 . The bearing block  20  designed as the mounting point for the pusher  5  has an axis of rotation  23  extending in the conveying direction F, on which the pusher  5  is rotatably supported, e.g., by a cam, in a plane standing transversely to the conveying direction F. In the present case, the slot  7  in the base  8  of the channel or the recesses  11 ,  12  of the guide walls  9 ,  10  form the cam by which the pusher  5  is supported. The pusher  5  is formed by a finger  24  that pushes against the rearward side of the book block  3  to convey it. The finger  24  has a U-shaped cross section adjacent to the predetermined breaking zone, and the sidepieces  25 ,  26  of the U-shaped cross section extend away from the conveying direction F. In the direction of the longitudinal extension of the pusher finger  24 , the sidepieces  25 ,  26  have a diminishing cross section, at least in a section  27  after the predetermined breaking zone  28 . In the predetermined breaking zone  28 , the pusher finger  24  is connected by spaced connecting pieces  29  running transversely to the conveying direction F with a hub  30  of the pusher  5  (See  FIG. 4 ). 
   The hub  30  is arranged on the axis of rotation  23 . The pusher  5  is connected by the hub  30  with the bearing block  20 , which is mounted on the traction mechanism or roller chain  4 . The pusher  5  is connected with the bearing block  20  by a socket pin  31 , which passes through two bearing webs  32 ,  33  of the bearing block  20 , which are spaced apart in the conveying direction F, and through the hub  30  of the pusher  5 , which (hub  30 ) is arranged between them (eee especially  FIG. 6 ). 
   The socket pin  31  forms the axis of rotation  23 . The socket pin  31  is designed in such a way that, on the one hand, it can be passed through only from one end of the bearing block and, on the other hand, can be passed through both parts only at one end of the hub  30 . This makes it possible for the pusher  5  to be placed in the correct operating position during a change, and for the socket pin  31  to be secured on the bearing web  32  provided for this purpose. To this end, the hub  30  of the pusher  5  has a bore  34 , which has a larger diameter at the insertion end  35  of the socket pin  31  than at the exit end  36 . Accordingly, the insertion hole of the bearing web  33  is larger than the exit hole of the bearing block  20  at its opposite end. 
   To secure the socket pin  31 , a lug  37  is mounted on the bearing web on the exit side. It forms part of a locking mechanism  41  for preventing the socket pin from moving out of the operating position in the direction of the axis of rotation  23 . The other essential parts of the locking mechanism  41  are a circular groove  38  in a bore  39  of the lug  37  and a snap ring  40  inserted in the groove  38 , which snap ring ( 40 ) catches in an annular groove  41  in the socket pin  31 . So that the socket pin  31  can be easily inserted in the different bore diameters, its front end is shaped like a conical frustum. The pusher  5  is preferably an injection-molded plastic part, which has a projection  42  at its free end for reinforcement. 
   The invention is not limited by the embodiments described above which are presented as examples only but can be modified in various ways within the scope of the protection defined by the appended patent claims.