Abstract:
The present invention is related to a paper conducting cylinder ( 8 ) of a folder assembly ( 1 ). A cylinder surface ( 18 ) has a plurality of counterparts ( 23 ) for cooperation with cutting elements of a cutting cylinder ( 3 ). Product seizing element ( 24 ) being assigned to said paper conducting cylinder circumference ( 18 ) are located adjacent to said counterpart ( 23 ) and said cylinders ( 8 ) surface ( 18 ). Said product seizing element ( 24 ) perform an extending movement about a first pivot point ( 25 ) and a seizing movement about a further pivot point ( 26 ).

Description:
BACKGROUND INFORMATION 
     1. Field of the Invention 
     The present invention is related to a product seizing element in a folder apparatus, having at least one folding cylinder the surface of which forwards products along a respective product travel pass. 
     2. Background of the Invention 
     U.S. Pat. No. 5,484,379 discloses a folder assembly for printing presses. A folder assigned to a web-fed rotary printing press includes a pair of cooperating collecting and cutting cylinders to sever a web of paper into web segments. A belt conveyor system enwraps a portion of the surface of the collecting cylinder just before an intake point of paper ribbon between the collecting cylinder and the cutting cylinder. This belt conveyor system prevents the newly created leading edge of the paper ribbon from springing back. 
     According to the solution of U.S. Pat. No. 5,484,379 a belt conveyor system is arranged adjacent to said collecting cylinder. Said belt conveyor system contacts a leading edge portion of the web of material disposed on the preferred surface of said collecting cylinder. Said belt conveyor system imparts on said leading edge of the web of material in a direction of paper web travel. Thus, said collecting cylinder and said belt conveyor system impart a prestress in said direction of paper web travel of said leading edge with respect to the cylinders surface. By prestressing of said leading edge of said web of material with respect to the cylinders surface the leading edge is forced to slip on the respective cylinders surface. Depending upon the paper stock, the number of ribbons included in the respective web of material, the accuracy of folds to be performed in the later stages depends upon the position in which said newly created lead edge of the web of material is seized by respective seizing elements. 
     SUMMARY OF THE INVENTION 
     In view of the technical problems encountered in the solution according to the prior art, it is an object of the present invention, to provide for a secure seizing of the new leading edge of the web of material from which respective products are severed without interference of the seizing elements with the cutting operation. 
     A further additional or alternate object of the present invention is to provide for a motion of seizing elements of said lead edge of the web of material by reliable elements. 
     A still further additional or alternate object of the present invention is to allow for positive control of the respective products severed from the incoming web of material. 
     According to an examplary embodiment of the present invention, a paper conducting cylinder of a folder assembly includes: 
     A cylinder surface having counterparts for cooperation with cutting elements of a cutting cylinder, 
     product seizing elements assigned to said counterparts on said cylinder&#39;s surface, 
     said product seizing elements performing an extending movement about a first pivot axis and 
     said product seizing elements performing a seizing movement about a further pivot axis. 
     The advantages of the solution according to the present invention are given by the fact that said leading edge portion of the web of material is not subject to a relative movement with respect to the paper conducting cylinder surface. Thus, no misregistration within a leading edge of a web of material comprising a plurality of ribbons occurs. Still further, a motion is imposed on a respective seizing element in a two-step-manner, to allow for an extending movement after the cutting action has resulted in a cut in a first step and then to allow for a seizing motion of a head portion of a seizing element from an upward opened, extended position into a downward directed seizing motion in a second step. 
     In further advantageous embodiments of the present invention said seizing elements comprise a first and second portion, respectively. Said second portion has an inclined hook-shaped portion to seize a respective leading edge of a web of material. Said leading edge may have a number of layers or ribbons, respectively, to be reliably secured by said seizing element without imposing a relative movement on to said leading edge of the web of material when arranged upon the paper conducting cylinder&#39;s surface. Said product seizing elements are arranged on the circumference of said paper conducting cylinder, assigned to each of respective cutting counterparts on said cylinder surface for the respective cutting operations. For an actuation of said product seizing element on the cylinder surface a plurality of actuating elements are provided to impose a two-step-motion on said respective seizing elements. 
     Said actuating elements comprise a cam element which may be shaped as a double track cam, having a respective first track and a respective second track. Said tracks include first and second profiles each having low and high dwell-sections, respectively. Said profiles of the respective tracks are the respective cam surfaces cooperating with respective actuating elements such as cam followers of said seizing elements. 
     Said actuating elements include a fixed pivot axis to which said product seizing element is fastened. Between said fixed pivot axis and said product seizing element a linking element such as a lever or like is mounted. A further actuating element, cooperating with one of said tracks of said double track cam rotates via a link member about a respective secondary pivot axis. Thus, when said second actuating element will rotate via a link member said rotating movement about its secondary pivot axis to extend said seizing element into an extended position about the respective cylinder surface. 
     Said secondary pivot axis corresponds to a first cam follower cooperating with said previously mentioned first cam profile. In following said first cam profile said first cam follower will be lifted into an extended position moving said product seizing element into an extended position beyond said respective portion of the paper-conducting cylinder surface. Followed by a second actuating element following the respective cam on the respective second track said seizing element being in an extended position will be rotated from its upward position about a secondary pivot axis into a downwardly directed motion a seizing motion thus seizing the respective leading edge of a web of material without imposing a relative movement on to said leading edge of said web of material. 
     A paper conducting cylinder having a dual-operated-seizing element according to the above mentioned description is advantageously used in a folder apparatus for commercial and newspaper applications. 
     According to a method of operating a product seizing element a respective product seizing element assigned to the paper conducting cylinders surface extends from a retracted position into an extended position beyond said cylinders surface in a first actuating step and in a second actuating step said product seizing element is moved from an extended position in a downwardly directed movement towards said leading edge position on said paper conducting cylinder surface. Said extending movement step and the seizing movement step performed in a substantially downwardly directed manner will follow each other subsequently for a seizing action without interference with the cutting operation. Said first step describing an extending movement of said product seizing element first portion will move said product seizing element&#39;s first portion into an upward position. Upon actuation of said second actuating element such as a cam follower said product seizing element being in an extended position is moved in a substantially downwardly directed manner to seize the respective multi-layered ribbon of the respective web of material on the surface of the paper conducting cylinder. The respective downwardly directed movement of said product seizing elements first portion towards the paper conducting cylinders surface eliminates any relative movement of said leading edge since said cut leading edge is seized substantially in its registered position in the vicinity of said groove within which said cutting counterparts such as anvil bars are received on the respective paper-conducting cylinder surface. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The novel features which are considered characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation together with additional objects and advantages thereof, will be best understood from the following description of a specific embodiment when read in connection with the accompanying drawings, in which: 
     FIG. 1 is a side elevation of a folder assembly, 
     FIG. 2 shows a product seizing element in its respective retracted position to allow for a cutting operation, 
     FIG. 3 shows said product seizing element in its respective intermediate position extended above the paper conducting cylinders surface and 
     FIG. 4 shows said product seizing element in its respective closed position having seized a respective leading edge of a web of material. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     According to FIG. 1, a side elevation of a folder assembly is given in greater detail. 
     FIG. 1 shows a general side view of an exemplary embodiment of a folding apparatus  1  according to the present invention wherein a folding cylinder scheme and a path of product-transporting conveying means within the folder are illustrated. In a frame of a folding apparatus  1 , there is arranged a cutting cylinder  3  comprising a knife and cooperating with counterparts on the surface of a respective first paper-conducting cylinder  8 . Perforating units represented as cross-perforating cylinders  2  can also be included to cross-perforated web material before it is severed into products or signatures. The web material is transported by nip rollers  21  through the perforating cylinders  2  and through seizing rollers  22  to the cutting cylinder  3 . A transport system is provided with first and second conveying tapes  4 ,  5 , respectively. Assigned to the conveying tapes  4 ,  5  there are tape tensioning devices  6 ,  6 ′. Integrated into the conveying path of the tapes  4 ,  5  are combing rollers  7  which smooth the product as it is transported are provided. 
     Through conveying tapes  4 ,  5 , respectively, products are conveyed to a first paper-conducting cylinder  8 . The products then are conveyed in a counter clockwise direction to a fold of area  13  at a nip between the collecting cylinder  8  and a folding or jaw cylinder  14 . Through belt  4 , the products are conveyed to a surface  18  of the collecting cylinder  8  through an entering section  12  having each product under positive control. Having reached the fold off area  13  the products are tucked by tucker blades—which are not shown in greater detail—into folding jaws  15  arranged on a circumference  19  of a second product-conducting cylinder  14 . 
     A transversal fold is, in an examplary embodiment performed at the middle of a product (that is, at a product mid-point), when one half of the length of the product to be transfered and cross folded has reached the circumferential section below a product-guiding device  9 , having a smoothing element  11 . Upon tucking one half of the product into a corresponding jaw  15  of the jaw cylinder  14 , an upper half of the product travels in a counter clockwise direction on the cylinder&#39;s surface  18  of the first paper conducting cylinder  8  or collecting cylinder, while the lower half of the product follows the second paper-conducting  14  in a clockwise direction. The product is pulled by the jaw cylinder  14  to leave the collecting cylinder  8  in a clockwise direction below a smoothing element  11 , which extends in a clockwise direction. Within a transfer area  17 , the product is subjected to high forces of acceleration, resulting in a whipping effect of the product edges. The guiding device  9 , having the smoothing element  11 , is afixed to a respective shield which is mounted within the folding apparatus. 
     FIG. 2 shows a product seizing element in its respective retracted position to allow for a cutting operation. 
     In a respective starting position  37 , a dual-operated-product seizing element  24  is shown in its retracted position. Along a respective circumference  18  of a first paper-conducting cylinder  8 , a plurality of product seizing elements  24  corresponding to the number of cutting counterparts  23  are arranged. The product seizing elements  24 , each comprise a first portion  24 . 1  and a second hook-shaped portion  24 . 2 , respectively. Assigned to a respective first paper conducting cylinder  8 , is an actuating cam  31  which is shown here as a double track cam having two respective cam tracks  34 ,  35  respectively. On the other hand said actuating cam may include 2 independently phaseable cams each having respective tracks  34 ,  35 . Through two independent cams  34 ,  35  an independent phasing of the respective two-step-movement of the product seizing element  24  can be adjusted independently. Said two cam tracks  34 ,  35  respectively each comprise a first and a second profile  32 ,  33  respectively. As will be described in greater detail below, said profiles  32 ,  34 , respectively each comprise high dwell and low dwell portions for initializing the respective actuating periods of said plurality of product seizing element  24 . 
     Said product seizing element  24  is fastened with its first portion  24 . 1  with respect to a secondary pivot axis  26 . Co-axially to said secondary pivot axis  26  an actuating element  29  such as a cam follower  29  is mounted rotatably. From said secondary pivot axis  26  to respective linking members  27 ,  28  extend to a first pivot fixed  25  and to a second actuating element  30 , such as a cam follower following the profile of the respective second cam track  35 . On the respective cylinder surface  18  of said first paper conducting cylinder  8  a groove  36  is shown receiving said counterpart  23 —such as an anvil bar—with which the respective knives of the cutting cyliner  3  according to FIG. 1 cooperate upon a cutting operation. 
     FIG. 3 shows said product seizing element in its respective intermediate position extended above paper conducting cylinder&#39;s surface. 
     According to this configuration said secondary pivot axis  26  is moved by the first cam profile  32  of the first track  34  into an upward position. In the position of the secondary pivot axis  26  may be moved in its upward position by the respective high dwell portion by slight rotation about said fixed pivot  25 . As schematically given here said actuating element  29  on which said seizing element  24  is mounted is extended by cam follower  29  following the respective first track  34  of said cam  31 . The degree of opening of said seizing element  24  said seizing element&#39;s  24  first portion  24 . 1  relative to a respective lead edge portion  40  may be varied by phasing of the cam tracks  34 ,  35  with respect to one another. 
     By having the respective second actuating element  30  passing said second cam profile  33  in a low dwell portion, said linking member  28  moves said secondary pivot  29  in counter-clockwise direction providing for a high degree of opening of the seizing element  24 . Thus, thicker leading edges of webs of materials can be accurately seized since all of the ribbon layers will be seized in a downwardly directed motion of the respective first portion  24 . 1  of the respective seizing element  24  at once. The motion of the respective seizing element  24  shown in FIG. 3 corresponds to the first step, i.e. an intermediate position  38  of the seizing element  24 . In this stage, the respective seizing element  24  has just opened according to a predetermined degree depending upon the thickness of the leading edge of the web of material to be processed in the folder apparatus  1  according to the present invention. 
     FIG. 4 shows said product seizing element in its respective closed position having seized a respective leading edge of a web of material. 
     In following upside intermediate position  38  as given in previously described FIG. 3 said product seizing element  24  now adopts a closed position  39  with respect to the leading edges position  40 . The respective secondary pivot axis  26  and accordingly said actuating said second actuating element  29  being moved in its upward position, the second movement step, i.e. the closing of product seizing element  24  is achieved by the second actuating element  30  contacting a high dwell position of the respective second track  35  having a second cam profile  33 . Via a second linking member  28  said secondary pivot axis  26  will be rotated in clockwise direction, thus causing said product seizing element  24  to move substantially downwards contacting a respective leading edge of a web of material above said leading edge position, indicated by reference numeral  40 . Depending upon the high dwell position of said first track  34  and the respective low dwell position of said second track  35 , the degree of opening of the seizing element  24  is determined and adjustable. On the other hand by the respective high dwell position of the second track  35 , the extent to which the hook-shaped first portion  24 . 1  of the product seizing element  24  is moved downwards with respect to the leading edge of the web can be varied. By phasing of two independently adjustable cam tracks  34 ,  35  with respect to one another the extent of closing and the amount of the seizing force exerted upon the respective leading edge can be adjusted individually according to print job requirements. 
     The dual-action-seizing can be performed—although not shown here in greater detail—by actuation of said seizing element  24  via electric actuators such as electric motors. The product seizing element  24  according to the present invention are used in folders on respective paper-conducting cylinders, such as collecting cylinders, folding cylinders and/or jaw cylinders. 
     REFERENCE NUMERAL LIST 
       1  folder apparatus 
       2  perforating cylinders 
       3  cutting cylinder 
       4  conveying tapes 
       5  conveying tapes 
       6  tape tensioning means 
       7  combing rollers 
       8  first paper conducting cylinder 
       9  product guide 
       10  shield 
       11  smoothing element 
       12  rollers 
       13  fold-off area 
       14  second paper conducting cylinder 
       15  folding jaws 
       16  conveying tape 
       17  transfer area 
       18  cylinder surface 
       19  circumference 
       20  second perforating cylinders 
       21  nip rollers 
       22  seizing rollers 
       23  bars 
       24  seizing element 
       24 . 1  first portion 
       24 . 2  second portion 
       25  fixed pivot 
       26  secondary pivot 
       27  first linking member 
       28  second linking member 
       29  first cam follower 
       30  second cam follower 
       31  double track cam 
       32  first cam profile 
       33  second cam profile 
       34  first track 
       35  second track 
       36  groove 
       37  starting position 
       38  intermediate position 
       39  closing position 
       40  lead edge position