Abstract:
A system for gathering printed products includes a transport device and feed devices for the printed products, which form a gathering line, wherein the transport device has receiving points for the printed products located at regular intervals on a revolving traction apparatus. A sensor, which monitors the functionality of the receiving points along the transport line to detect defects, is connected to a control unit, which determines the feed of the printed products to the receiving points of the transport device.

Description:
BACKGROUND OF THE APPLICATION 
     1. Field of the Invention 
     The present invention relates to a system for gathering printed products along a gathering line formed by a transport device and feed devices for the printed products, where the transport device has receiving points for the supplied printed products located at regular intervals on a revolving traction mechanism. 
     2. Description of the Related Art 
     Systems of the type indicated above are used in the further processing of printed products, namely, to gather the flat products, especially printed products, into loose stacks of material. “Flat products” are understood to be folded sheets, cards, CD/DVD-ROMs, or merchandise samples. The gathered printed products are then sent to an additional processing step, where they are usually bound with wire or glue. 
     Feed devices, each of which is loaded with one of the types of printed product to be gathered, are located along a horizontal transport line. Receiving points or catch elements attached at regular intervals to a revolving, driven traction mechanism are conducted past all of the feed devices during one revolution and thus loaded with the printed products. Depending on the type of gathering system, the printed products can be transported either lengthwise or crosswise to their flat sides during the gathering process. So that the printed products can be bound with glue, they are laid on top of each other in the closed state to form a stack and then glued along one side in a glue binder. A sheet-gathering machine of the standard type is disclosed in CH 635 046. If the printed products are to be stitched after gathering, they must first be opened in the middle and then laid down on top of each other in the opened state. 
     It is possible that, because of defective printed products or malfunctions, the receiving points can be so badly damaged that they can no longer operate properly. In systems according to the prior art, defective parts must be replaced before production can resume. Under certain conditions, this can take a long time and thus significantly delay the completion of the run. This is especially irksome when there are only a few copies left to be finished and the truck hired to deliver them is already waiting at the loading dock. 
     SUMMARY OF THE INVENTION 
     In a system for gathering flat printed products, the invention is based on the object of keeping the production process running even after certain of the receiving points of the transport device have become defective. 
     The object is met according to the invention in that a sensor, which detects defective receiving points on the transport device, is located along the transport line and is connected to a control unit, which determines the feed of the printed products to the receiving points of the transport device. 
     The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       In the drawing: 
         FIG. 1  is a simplified perspective view of an inventive gathering device for a glue binder; and 
         FIG. 2  is a simplified perspective view of an inventive gathering device for a saddle stitcher. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The gathering devices  1  shown in  FIGS. 1 and 2  consist essentially of a transport line  2 , which is formed by a transport device  12  and feed devices  3 , arranged along the length of the transport device  12 . The transport device  2  has means  9  (not shown in  FIG. 1 ) on which stacks  10  of printed products  4  are formed, which are conveyed on a revolving, driven traction mechanism  7  with catch elements  13  attached at regular intervals. The gathering device  1  according to  FIG. 1  could be used to gather stacks  10  for a glue binder, whereas the gathering device according to  FIG. 2  could be used for a saddle stitcher with a stitching machine  20 . During the gathering process for the glue binder, the various printed products  4  are laid on top of each other by the feed devices  3 , located along the line of the transport device  12 , so that the stacks  10  are complete by the time they reach the end of the transport device  12 . During the gathering process for the saddle stitcher according to  FIG. 2 , the printed products  4  are gathered and set down astride, in the opened state, onto a roof-shaped support surface formed by the means  9 . The traction mechanism  7  is connected to a drive (not shown) and uses its working run  11  to transport the stacks  10  by means of the catch elements  13  in the transport direction F. 
     The feed devices  3  are preferably formed by sheet feeders  14 , which take the printed products  4  individually from the stacks  22  and deposit them on feed conveyors  15 , by means of which the printed products  14  are set down in the correct position on the growing stacks  10 . The expert in the field is familiar with sheet feeders  14  of various types. In  FIGS. 1 and 2 , the sheet feeders  14  are designed as drum feeders by way of example. The lowermost printed product  4  of each stack  22  is partially removed from the stack  22  by suction means, then gripped by grippers mounted on the drums, carried away from the stack, and deposited on the feed conveyor  15 , which places the printed product  4  in the correct position and at the correct speed onto the stack  10  of sheets being transported along underneath. Each feed device  3  is connected to the control unit  16 , which has a keyboard  19  and a display  18  for the exchange of control signals. This can be accomplished by way of a control line  17 , which, in the present example, is illustrated as a bus. It is also possible, however, to use other linking technologies for the exchange of signals known in the field of control technology. For example, each feed device  3  could be connected to the control device  16  by its own separate line. 
     The control unit  16  is thus able to activate or to deactivate the feed devices  3 , to adjust formats, and to receive control signals from the feed devices  3 , which indicate, for example, whether or not a printed product  4  of the correct thickness has been taken from the stack  22  or has been taken from the stack correctly. So that the control signals can be coordinated properly in time, at least one position sensor  21  is provided on the drive of the traction means  7 ; this sensor is also connected to the control unit  16  by means of a control line  17  or a separate line. 
     Along the gathering line  2  of the transport device  12 , furthermore, sensors  8  are provided to monitor the status of the receiving points  5 ,  6 . Thus any catch elements  13  which have been deformed or broken off completely, for example, and which cannot continue to fulfill their function can be detected. It is also conceivable, however, that the status of the catch elements and their functionality could be detected by additional components inside a receiving point  5 . The sensors  8  are also connected to the control unit  16  either by the control line  17  or by separate lines. 
     Any known type of sensor can be used as the sensor  8 . Sensors using direct optical, electrical, or mechanical detection are preferred. Sensors  8  using electrical detection are usually based on inductive or capacitive principles. Also conceivable is the use of RFID systems (Radio Frequency Identification). 
     The sensors  8  are preferably located before the start or after the end of the gathering line, because there the access space required for repairs is available. If, on the basis of a sensor  8 , the control unit  16  establishes that a defective receiving point  6  is present, the gathering device is stopped briefly and manually loosened or emptied. The operator must now decide whether to continue the production run with one or more defective receiving points  6 . The control unit  16  will assist him with this decision to the extent that, after entering the time required for the repair via the keyboard  19 , it will show him on the display  18  the expected times at which production will be complete with and without the repairs. To calculate these times, the control unit  16  will take into account the number of copies still to be produced, the production speed, the repair time, the number of defective receiving points  6 , and the total number of receiving points  5 ,  6 . 
     While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.