Abstract:
Folded signatures are delivered to a paddle wheel and then are transported to a plurality of distribution points by a gripper chain with a plurality of grippers. A controllable switching unit is provided at each distribution point in the form of a rotatable cam disk with switching cams. The rotatable cam disk at each distribution point is caused to rotate by an individual motor at a controlled speed and time. The speed of rotation of each cam disk can be greater than the speed of travel of the gripper chain so that the point of release of each signature can be accurately controlled.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a device for transporting folded signatures which are held by controllable grippers. The folded signatures are transported and distributed to a pluarlity of distribution points. 
     DESCRIPTION OF THE PRIOR ART 
     A art device is known from WO 96/06032. A ratchet wheel having several control cams is provided for controlling the grippers which are holding signatures. The circumferential speed of the ratchet wheel with the control cams is synchronized with the conveying speed of the gripper chain. The control cams each come slowly into contact from above with the control roller which is assigned to them and slowly push it into an “open position”. An exact delivery of the signatures is not possible in this way, so that the spacing between the scaled or layered signatures becomes irregular. This leads to interruptions of downstream-connected processing machines. 
     The object of the invention is based on creating a device for transporting and distributing folded signatures removed from a paddle wheel by means of a gripper chain. 
     In accordance with the invention, this object is attained by providing rotatable control devices which are exactly positioned to open the signature grippers at a desired location. The rotatable control devices have several control cams and can be moved between non-switching and switching positions. The speed of rotation of the control devices can be temporarily greater than the conveying speed of the gripper chain. 
     The advantages which can be achieved by means of the present invention reside in particular in that a gripper chain which has a simple structure is employed. Short switching times become possible, so that a respectively different distribution point can be provided for each folded signature even at high speeds of the gripper chain. For actuating the gripper mechanism, discontinuously drivable cam disks with several control cams are employed in an advantageous manner, which cam disks are controlled or regulated at exact angles of rotation. The control cams of a cam disk are moved into the movement path of the control roller of the gripper system and are stopped before the control roller reaches the switch location. Thus, the switching process takes place with the cam disk at a standstill. Therefore a “creeping” actuating process is avoided. The path of the gripper chain on its way to the several distribution stations can be kept straight or only slightly curved. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A preferred embodiment of the present invention is represented in the drawings and will be described in greater detail in what follows. 
     Shown are in: 
     FIG. 1, a schematic representation of a lateral view of the distribution device; 
     FIG. 2, a detail “Z” from FIG. 1 with an enlarged representation of a closed gripper; 
     FIG. 3, a detail “Y” from FIG. 1 with an enlarged representation of an open gripper; 
     FIG. 4, a detail “X” from FIG. 1 with an enlarged representation of a control cam, fixed in place on the frame, for closing the pivotable clamping jaw; and in 
     FIG. 5, a basic wiring diagram for driving the device in accordance with FIG.  1 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A known paddle wheel  2  is arranged underneath a belt system  1  coming from a folding device. The paddle wheel  2  can consist, for example, of four individual paddle wheels, fastened spaced apart from each other on a shaft  3 . A chain wheel  4  is also fastened on the shaft  3  and is arranged between the second and the third paddle wheel. On its circumference, the chain wheel  4  has, for example, fifteen teeth, and guides a gripper chain  6 . Spaces between the teeth of the chain wheel  4  are in interlocking connection with rollers  8  located on each chain link  7  as seen in FIGS  2 - 4 . 
     Each chain link  7  supports a gripper  9 , which consists of a fixed clamping jaw  11 , and a pivotable clamping jaw  12 , as seen most clearly in FIGS. 2 and 3. As shown in the lateral views of FIGS. 1-3, the fixed clamping jaw  11  is essentially designed in a V-shape and is fixedly connected with the chain link  7 . The pivotable clamping jaw  12  is designed as a first arm of a three-armed lever arm. A second lever arm of the three-armed lever is designed as a control lever  13  and supports a roller  14  at its free end. The control lever  13  can be actuated by having roller  14  ride on a control cam  16 , which, as seen in FIG. 4, is fixed on the frame and is located in the vicinity of the paddle wheel  2  and is used, for closing the pivotable clamping jaw  12 . The control lever  13  can also be actuated by having roller  14  ride on a cam disk  33  to  37 , which has yet to be described, for opening the pivotable clamping jaw  12 . A third lever arm of the three-armed lever is designed as a spring-tension lever  17 , which has the point of the application  18  of a force for a prestressed tension spring  19 . An abutment  21  or end for the tension spring  19  is located in the vicinity of the socket bottom  22  of the V-shaped fixed clamping jaw  11 . 
     All lever arms  12 ,  13 ,  17  of the three-armed lever arm have a pivot point  23  in their base. This pivot point  23  is connected with a bearing, which is located at the end close to the chain of one of the legs of the V-shaped fixed clamping jaw  11 . 
     The levers  13 ,  17  can also be arranged on both sides of each chain link  7 . Two spaced tension springs  19  and two rollers  14 , one on each side of each chain link  7  are then provided. 
     The lower belt of the endless gripper chain  6  consisting of the chain links  7  with the respective grippers  9  fixedly arranged thereon is passed in accordance with the technical production requirements past several distribution points A, B, C, D, E for distributing folded signatures  24 ,  26  received by the gripper chain  6  from the paddle wheel  2 , as shown in FIG.  1 . 
     The path of movement of the gripper chain  6  in the area of the distribution points A, B, C, D, E is preferably straight. At most, the path of chain  6  is slightly curved. 
     Such distribution points can be, for example: A, a shunt for waste, B, a removal point for test sheets, as well as C, D, E, deposit points for folded signatures  24 ,  26 . 
     A belt system  27  to  31  for receiving the deposited signatures  24 ,  26  is provided under each distribution point A to E. 
     A controllable switching unit, for example a cam disk  33  to  37 , is arranged at each distribution point A to E, as seen in FIG.  1 . Each cam disk  33 - 37  has several—for example three—control cams  38  evenly distributed over its circumference. Each cam disk  33  to  37  is connected, fixed against relative rotation, with a motor, whose angular rotational position is regulated, for example by a servo motor M 33  to M 37 , as seen in FIG. 5. A rotor of a position sensor L 33  to L 37 , fixed on the frame, is connected, fixed against relative rotation, with each cam disk  33  to  37 , as seen in FIG.  5 . Each position sensor L 33  to L 37  is an angle of rotation position sensor and is, for example designed as a rotary pulse sensor with a reference marker, and is arranged, for example, interlockingly, on its respective cam disk  33  to  37 . The motors M 33  to M 37 , as well as the position sensors L 33  to L 37  of each cam disk  33  to  37  are electrically connected with an actuation regulator F 33  to F 37  with integrated position detection. For the purpose of a data exchange, all actuation regulators F 33  to F 37  are connected via a data bus  39  with a computer unit  41 , all as is shown in FIG.  5 . The computer unit  41  is also electrically connected with switches S 33  to S 37  for the preselectable actuation of one or several distribution points A to E. 
     The shaft  3  of the paddle wheel  2 , or respectively of the chain wheel  4  is connected mechanically, for example with a drive motor M 2 ,  4 , as well as with a position and rpm sensor L 2 ,  4 , and thereafter with the computer unit  41 . This assembly is also schematically depicted in FIG  5 . 
     The shaft  3  of the paddle wheel  2 , or respectively of the chain wheel  4  can also be driven by means of a drive wheel train coming from the folding device. Unless represented differently, all of the above described devices are seated fixed in the lateral frame. 
     The operation of the device for transporting folded signature, in accordance with the present invention, is described in what follows. The signatures  24 ,  26 —which, for example are different—and are coming from the folding device via the belt system  1 , each continuously fall into their one paddle pocket of the paddle wheel  2 . The gripper chain  6 , which simultaneously circulates in the phase of the paddle wheel  2 , picks up every one of the sequentially arriving signatures  24 ,  26 . Following the roll-off of the respective rollers  14  of the control levers  13  on the control cam  16  fixed on the lateral frame, each signature  24 ,  26  is clamped in its associated one of the grippers  9  by the interaction between the pivotable clamping jaw  12  and the fixed clamping jaw  11 . In the course of this pivot movement of each of the three-armed control levers  13  (in a clockwise rotating direction as seen in FIG.  3 ), the tension spring  19  is pivoted from its stable open position through an extended spring dead center position into a stable closed position which is shown in FIG.  2 . When the spring  19  is in the dead center position, the abutment  21 , the pivot point  23 , as well as the point of the application of a force  18  are located on an imagined straight line. However, in the open position or the closed position the tension spring  19  is in a more relaxed stable position compared with the dead center position. Switching from one to the other position takes place with only a slight exertion of force and within a period of time of a few milliseconds. 
     If the signatures  24 ,  26  are to be deposited in the distribution points C and D, for example, the associated switches, for example the switches S 35  and S 36 , are activated. The rotation of the motors M 35 , M 36  over a rotationally accurate angle, and therefore an associated rotation of the cam disks  35  and  36 , is triggered by this actuation of switches S 35  and S 36 . The cam disks  33 ,  34  at the distribution points where no actual distribution takes place at that time, for example A, B, are then in a “non-control position”, in which the cam disks  33 ,  34  are in such a position that their cams  38  are outside of the movement path of the rollers  14  of the control levers  13  as seen in FIG.  2 . The switching—and non-switching—control faces can be straight and/or curved. In the present case the non-switching control face is not curved as shown in FIG.  1 . 
     For practical as well as for safety reasons, the cam disks  37  of the last distribution point E are always in the “signature off” position to assure that all signatures  24 ,  26  are removed on the last belt system  31  at the latest. In place of the cam disk  37 , it is also possible to provide a stationary control cam for opening each pivotable clamping jaw  12 , provided that opening has not already taken place previously. The roller  14  of a gripper  9  carrying a signature  24  enters the area of a non-switching section of the cam disk  35 . The cam disk rotates in a counterclockwise direction as shown in FIG. 1, so that a cam  38  comes into operational connection with the roller  14  of the control lever  13 . In the process, the lever  13  is pivoted in a counterclockwise direction as shown in FIG. 2, so the signature  24  is deposited on the belt system  29 . The same process is repeated at the cam disk  36  with a following signature  26 . There, the signatures  26  are deposited on the belt system  30 . 
     Preferably the rotation of each of the cam disks  35 , or respectively  36 , for opening the corresponding gripper  9  takes place discontinuously over an angle of rotation of respectively 120°. In the course of this, the cam disks  35 ,  36  act together in the above described manner with the motors M 35 , M 36 , the position sensors L 35 , L 36 , the actuation regulators F 35 , F 36  and the computing unit  41 . The motors M 35 , M 36  are preferably designed as step motors. 
     It is also possible to move all signatures via the belt system  27  to a waste container  42 , or to also include the distribution points B and E, not used so far. If all signatures  24 ,  26  are to be temporarily moved to the waste container  42 , it would be possible to employ a control cam, which can be pivoted into a “signature off” position by means of a work cylinder, in place of a cam disk  33 . 
     In summary, the essence of the invention lies in that a rotatable control device or cam disc  33  to  37  is provided, which has control cams which are controlled or regulated at exact positions of the angles of rotation, wherein the control cams are arranged in a switching or non-switching position on cam disks  33  to  37 . 
     The circumferential speed of the highest points  32  of the control cams  38  in the course of their movement from a non-switching movement into a switching position is greater, or at least temporarily greater than the conveying speed of the gripper chain  6 . 
     The direction of rotation of the cam disks  33  to  37  can always be either in the conveying direction or counter to the conveying direction of the gripper chain  6 . If switching times are not important, they can also be continuously back and forth. 
     In an advantageous manner, each pivotable clamping jaw  12  can be selectively individually actuated, i.e. for example, at a defined location so that only it and no other clamping jaw is actuated at a desired time at a particular location. 
     While a preferred embodiment of a device for transporting folded signatures in accordance with the present invention has been set forth fully and completely hereinabove, it will be apparent to one of skill in the art that a number of changes in, for example, the type of printing press being used to print the signatures, the type of folding device used to fold the signatures and the like may be made without departing from the true spirit and scope of the present invention which is accordingly to be limited only by the following claims.