Patent Document

FIELD OF THE INVENTION  
       [0001]     The present invention is directed to a device for inking a roller. At least one chamber doctor blade is placed against the roller for inking it.  
       BACKGROUND OF THE INVENTION  
       [0002]     DE 44 40 040 A1 discloses an inking unit with a screen roller and a doctor blade. The doctor blade supplies the screen roller with ink.  
         [0003]     An inking unit with a doctor blade extending over the entire length of a screen roller is shown in DE 40 01 734 A1 C2. The doctor blade has an inlet in one area near an end and an outlet in another area near an end for the ink.  
       SUMMARY OF THE INVENTION  
       [0004]     The object of the present invention is directed to providing a device for inking a roller.  
         [0005]     In accordance with the present invention, this object is attained by providing at least one chamber doctor blade which can be placed against the roller for inking the roller. Ink delivery lines or conduits are connected to the chamber doctor blade near both of its ends. The chamber doctor blade is supported so that it is pivotable about a shaft. The chamber doctor blade may have a length of at least four side-by-side newspaper pages. An outlet for excess ink may be provided in a center area. A pump may be assigned to each of the ink delivery lines or conduits.  
         [0006]     The advantages to be gained by the present invention lie, in particular, in that the ink supply to the roller to be inked takes place in a compact, cost-effective and rugged manner at high quality. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]     Preferred embodiments of the present invention are represented in the drawings and will be described in greater detail in what follows.  
         [0008]     Shown are in:  
         [0009]      FIG. 1 , an ink delivery device in accordance with the present invention by the use of two chamber doctor blade bars, in  
         [0010]      FIG. 2 , an ink delivery by the use of a continuous doctor blade bar, in  
         [0011]      FIG. 3 , a schematic side elevation view of a delivery device, and in  
         [0012]      FIG. 4 , a side elevation view of an alternative device for the delivery of the ink to the doctor blade bar in accordance with the present invention.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0013]     A printing group having a forme cylinder  01  is embodied, for example, as a double-width printing group of a printing press and has, as may be seen in  FIG. 1 , for example, in addition to application rollers and reciprocably-moving rollers, a roller  02 , and in particular a screen roller  02 , to which ink can be applied by the use of at least one doctor blade  03 , which may be, for example, a chamber doctor blade  03 . By use of the doctor blade  03 , ink can possibly also be applied directly to a printing forme, for example a rotogravure printing forme, of a roller  01  embodied as a forme cylinder  01 . The printing group, and therefore the forme cylinder  01 , are embodied to have a double width. The printing group has a length substantially corresponding to four side-by-side arranged printed pages, and in particular a length corresponding to the width of four vertical newspaper pages. In an advantageous embodiment, the printing group is configured as an offset printing group, so that the forme cylinder  01  works together with a transfer cylinder, which is not specifically represented, which transfer cylinder, in turn, works together, via the material to be imprinted, with a counter-pressure cylinder. The forme cylinder  01  has on its circumference one or several printing formes for planographic printing.  
         [0014]     In the first preferred embodiment, two doctor blades  03  are arranged side-by-side over the length of the forme cylinder  01 . These doctor blades are supported on a shaft  04 , which is divided in the first preferred embodiment, so that each of the two doctor blades  03  can be individually brought into or out of contact with the roller by that doctor blade&#39;s shaft segment being pivoted. An actuating assembly  06 , or positioning mechanism  06 , which is configured as a pressure medium cylinder and a lever mechanism, is connected to each shaft segment  04 . Each of the two actuating assemblies  06  are preferably configured so that they can be remote-controlled. Excess ink drips or runs into respective catch containers  07  which are arranged underneath each respective doctor blade  03 . These catch containers may be, for example, basins  07 , whose bottoms slope in such a way that the ink preferably runs into the lowest area. In this area of each basin  07  the ink is returned to the respective doctor blade  03 , and in particular to an outlying area, by at least one pump  08  via a delivery line  09 . As also depicted in  FIG. 2 , and described in connection therewith, ink can be delivered to each doctor blade  03 , in each of the two areas of each doctor blade near the ends of each doctor blade  03 .  
         [0015]     In a second preferred embodiment, as shown in  FIG. 2 , the ink delivery device has a doctor blade  03  extending over the entire length intended for printing, for example a length of four printed pages arranged side-by-side, which sole doctor blade  03  is arranged on a continuous and pivotable shaft  04 . In the second preferred embodiment represented in  FIG. 2 , two pumps  08  and two delivery lines  09  are provided. These are located, in particular, at both sides of a basin  07 , which basin also extends over the entire length intended for printing, which two pumps  08  deliver the ink to the doctor blade  03 , and in particularly to each one of two areas near the two doctor blade ends. The excess ink can run off in the center area of the doctor blade  03 , and in particular through an outlet especially provided for this purpose. In this way, eddies, possibly caused by the ink flow, are preferably located in a non-printing area between two printed pages. The shape of the doctor blade  03 , which is configured with a cross section in the shape of a partial circle, also helps in preventing irregularities of the flow and in preventing the sticking of the ink in corner and edge areas of the doctor blade  03 . By the embodiment of the doctor blade  03  extending over the entire length intended for printing, it is possible to ink the roller  02  continuously, i.e. without a stripe. Actuation of the doctor blade  03  is provided preferably by the provision of two actuating assemblies  06  assigned to the doctor blade  03 , and in particular by remote-controlled actuating assemblies.  
         [0016]     The doctor blade or blades  03  is or are preferably embodied in the shape of a slit tube as the doctor blade chamber which slit tube, in an advantageous manner, has a working doctor blade and a closing doctor blade in the area of the two spaced, axially extending edges of the slit in the tube.  
         [0017]     In a further development, it is possible, with an appropriately stiff or rigid construction of the doctor blade  03 , for the pivoting in and out of the one-piece doctor blade  03  to take place by the use of only one actuating assembly  06 , positioned for example, on one of the two sides or ends of the doctor blade  03 , or located in the center of the doctor blade  03 . The delivery of ink to the doctor blade  03  can also take place by the use of only one pump  08  and two delivery lines  09 , or possibly by the use of only one pump  08  and only one delivery lines  09 .  
         [0018]     As represented in  FIG. 3 , the movement of the doctor blade, or blades  03  in and out of contact with the roller  02  takes place, corresponding to  FIGS. 1 and 2 , around the shaft, or shafts  04  positioned close to the roller  02 . The delivery line  09  is embodied to be flexible, for example, and in particular is embodied as a hose  09 . Alternatively, it can also be of advantage to arrange the pivot axis of the actuating assembly  06  at the height of the basin, or basins  07 , as represented in  FIG. 4 . In this configuration, the ink can be delivered in a non-movable rigid line, which is not specifically represented here, and wherein a rotatable coupling must be provided in the area of the pivot axis of the doctor blade lever.  
         [0019]     In a correspondingly rigid embodiment, the doctor blade  03  depicted in  FIG. 2  as extending over the entire width of the roller  02 , can also be applied in connection with even wider rollers  01 ,  02 , for example with rollers  01 ,  02  having a width of six printed pages. In this case, three doctor blades  03 , or two doctor blades  03 , each extending over respectively two or three printed pages, are arranged side-by-side, for example, in a manner similar to that depicted in the embodiment in accordance with  FIG. 1 .  
         [0020]     While preferred embodiments of a device for inking a roller, in accordance with the present invention, have been described fully and completely hereinabove, it will be apparent to one of skill in the art that various changes in, for example, the type of ink being used, the type of ink pump used and the like could be made without departing from the true spirit and scope of the present invention which is accordingly to be limited only by the appended claims.

Technology Category: b