Patent Publication Number: US-6698746-B2

Title: Crosscutter

Description:
BACKGROUND OF THE INVENTION 
     FIELD OF THE INVENTION 
     The invention relates to a device for transporting sheets from a crosscutter to a sheet-fed processing machine, in particular a printing press. A paper supply roll is provided for the crosscutter, from which a web of paper is drawn and supplied to the crosscutter. The crosscutter, which cuts the web of paper into the sheets to be processed, if necessary or desirable, has a device for forming a shingled or overlapping stream of sheets, which is supplied to the sheet-fed processing machine. 
     Such a device has become known heretofore from the German Utility Model (DE-GM) 7601552, for example. In addition to the crosscutter, the device shown therein has a sheet pile feeder, which is selectively activatable. If the sheet-fed processing machine is supplied from the paper roll feeder and the crosscutter, then the suction head of the sheet pile feeder, which is provided for handling the sheet pile, remains out of operation. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to provided a device for transporting sheets from a crosscutter to a sheet-fed processing machine, which guides the single sheets produced by the crosscutter, or the shingled or underlapping sheet stream made up of a succession of sheets one under the other, in the region of the suction head of the sheet pile feeder. 
     With the foregoing and other objects in view, there is provided, in accordance with the invention, a device for transporting sheets in a region of a selectively usable sheet pile feeder, comprising a crosscutter of a sheet-fed processing machine having conveyor belts and contact-pressure devices cooperating therewith for feeding the sheets from the crosscutter, and a separating device of the sheet pile feeder, whereon contact-pressure devices are disposed. 
     In accordance with another feature of the invention, the contact-pressure devices disposed on the separating device of the sheet pile feeder are remotely adjustable in one direction selected from the group thereof consisting of in the direction of the sheet transport and counter thereto, respectively, by the separating device. 
     In accordance with a further feature of the invention, the contact-pressure devices disposed on the separating device of the sheet pile feeder is adjustable in height by the separating device. 
     In accordance with an added feature of the invention, the sheet-transporting device includes a motor-drivable threaded spindle and a linear guide. 
     In accordance with an additional feature of the invention, the sheet-transporting device includes a further motor-drivable threaded spindle. 
     In accordance with yet another feature of the invention, the sheet-transporting device includes drive motors for remote adjustment connected to a control computer of the sheet-fed processing machine. 
     In accordance with yet a further feature of the invention, the contact-pressure devices, respectively, disposed on the separating device of the sheet pile feeder are embodied as rotatably supported brush rollers. 
     In accordance with yet an added feature of the invention, the brush rollers, respectively, are supported on the end of a leaf spring, and the leaf springs are disposed, displaceable transversely to the sheet transport direction, on a cross member. 
     In accordance with yet an additional feature of the invention, the cross member is secured to the separating device. 
     In accordance with a concomitant feature of the invention, the separating device is a suction head of the sheet pile feeder of a sheet-fed rotary printing press. 
     Advantageously, in the working region of the suction head, contact-pressure rollers are provided, which cooperate with conveyor belts of the crosscutter and thus assure accurate transport of the sheets in cadencing rollers which are provided. The contact-pressure rollers are secured to the suction head and can therefore be adjusted via the adjusting devices of the suction head. The suction head has a device that makes it possible to adjust for different paper sizes or formats. By this provision, the suction head, for example, assuming a preadjustment of the sheet-fed processing machine to the sheet size or format to be processed, can be preadjusted automatically via a control computer of the sheet-fed processing machine. By the disposition of the contact-pressure rollers on the suction head, in accordance with the invention, the adjusting device of the suction head serves for automatically adjusting the contact-pressure rollers. 
     Other features which are considered as characteristic for the invention are set forth in the appended claims. 
     Although the invention is illustrated and described herein as embodied in a crosscutter, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. 
     The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, wherein: 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1, a diagrammatic side elevational view of a sheet-fed processing machine, such as a printing machine, with a sheet pile feeder and a roller feeder; 
     FIG. 2 an enlarged fragmentary view of FIG. 1, further showing schematically and diagrammatically, a conveyor or feed path in the region of the sheet pile feeder; and 
     FIG. 3 is a top plan view of FIG.  2 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings and, first, particularly to FIG. 1 thereof, there is shown therein a rotary printing press, for example, a printing press  1  for processing sheets  7 , having a feeder  2 , at least one printing unit  3  and  4 , respectively, and a delivery  6 . The sheets  7  are taken from a sheet pile  8  and fed, then are either separated or singled into individual sheets or in a shingled or underlapping stream, to the printing units  3  and  4  via a feeding tray or table  9 . Each of the printing units  3 ;  4 , in a known manner, includes a plate cylinder  11 ;  12 . The plate cylinders  11  and  12 , respectively, have a device  13 ,  14  whereon flexible printing plates are fastened. Each plate cylinder  11 ;  12 , respectively, has also assigned thereto a respective device  16 ;  17  for changing printing plates semi-automatically or fully automatically. 
     The sheet pile  8  rests on a pile or stacking tray  10  that can be raised in a controlled conventional manner. The sheets  7  are taken from the top of the sheet pile  8  by a so-called suction head  18  which, among other elements, has a number of lifting suction cups or suckers and pull or forwarding suction cups or suckers  19  and  21  for singling or separating the sheets  7 . Moreover, non-illustrated blast or blower devices for loosening the upper sheet feeders and key elements for readjusting the sheet pile are also provided. For aligning the pile  8 , and especially the upper sheets  7  of the pile  8 , a number of lateral and rear stops are provided. 
     To enable the sheet-fed processing machine  1  to be supplied selectively with rolls of paper instead, a non-illustrated roller feeder is located upline of the sheet pile feeder  2 . The roller feeder, among other elements, has a non-illustrated roll of paper and a crosscutter  26 , which cuts a web of paper  27  into individual sheets  9  transversely to the transport direction, by a knife cylinder  28  and a counter-cutting cylinder  29  cooperating therewith. The crosscutter device  28 ,  29  is followed by a device for forming a succession of underlapping sheets, i.e., sheets lying shingled under one another. From the single sheets furnished by the crosscutter, this thus produces a stream of staggered underlapping imbricated sheets. A number of conveyor belts  32  located Side-by-side transport the imbricated stream in the region of the feeder to feeder rollers  33  at the beginning of the feeding tray or table  9 . 
     To establish good contact of the imbricated stream of sheets with the conveyor belts  32 , a number of contact-pressure rollers  34  are provided, which are secured to the suction head  18  of the sheet pile feeder  2 . The contact-pressure rollers  34  are embodied as rotatably supported brush rollers, respectively, secured by a leaf spring  35  to respective mounts or holders  36 , which are supported, so as to be displaceable crosswise, on a cross member  37  extending transversely to the sheet transport direction. The cross member  37  is secured on the suction head  18 . The suction head  18  is disposed, adjustable in elevation, by a vertically disposed, motor-adjustable threaded spindle  39 . The threaded spindle  39  is supported on a trolley  41 . The trolley  41  is guided by two rails  42  and  43  and is adjustable in and counter to the sheet transport direction by a motor-driven threaded spindle  44 . The drive motors  47  and  48 , respectively, of the threaded spindles  39  and  44  are connected for control purposes to a control computer  46  of the sheet-fed processing machine  1 . 
     When roll paper is being processed, it is necessary for the stream of imbricated sheets, underlapping one another, which are transported in the feeder region, to be pressed against the conveyor belts  32  by the contact-pressure rollers  34 , so that there will be no slip between the conveyor belts  32  and the underlapping imbricated sheet stream. As seen in FIG. 3, spacing a of the contact-pressure rollers  34  relative to the feeder rollers  33  is dimensioned so that the frontmost sheet, upon reaching the feeder rollers  33 , has left the contact-pressure region of the contact-pressure rollers  34 . When different format lengths are being processed, the spacing a is adjusted by displacement of the suction head  18  by the threaded spindle  44  in or counter to the sheet transport direction. An elevation or height adjustment of all the contact-pressure rollers  34  disposed on the cross member  37  is performed by the threaded spindle  39 . An adjustment of the contact-pressure rollers  34  transversely to the sheet transport direction is performed by fastening screws  49  assigned to each mount  36 . 
     An adjustment of the height h of the contact-pressure rollers  34  relative to the conveyor belts  32  and of the spacing a of the contact-pressure rollers  34  relative to the feeder rollers  33  can be effected by remote adjustment, automatically, via the control computer  46  as a function of the sheet size or format and sheet thickness.