Abstract:
Device for washing an inking unit provided at a printing machine. A doctor-blade device is provided at a distributor roller of an arrangement of rollers positioned before the split in the primary ink flow, while at least another doctor-blade device is provided at a distributor roller among a set of inking rollers supplying a secondary branch of the primary ink flow to a rearwardly disposed set of ink applicator rollers, as viewed in the direction of rotation of the plate cylinder.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to a device for washing an inking unit provided at a printing machine. Such a printing press or machine can generally comprise at least one device for supplying a cleaning agent and another device for wiping off the used cleaning agent, soiled by ink residues, from an inking-unit roller. 
     2. Background Information 
     In a known cleaning device of the kind described above, as disclosed in Federal Republic of Germany Laid-Open Patent Application No. 36 06 006, devices are used which supply the cleaning agent and apply it onto the rollers. After a number of rotations of the inking unit, the ink residues adhering to the rollers are dissolved. Then, the cleaning agent which is soiled by the ink residues is wiped off by means of a doctor-blade device. Unfortunately, however, this process requires a number of rotations of the inking unit. With today&#39;s conventionally sized inking units comprising a plurality of ink rollers and with the modern washing agents which are based on vegetable oil, the wiping-off usually takes longer, and, during this time, the machine is not available for printing. 
     OBJECT OF THE INVENTION 
     Proceeding from the above facts, it is the object of the present invention to considerably reduce the wash-up time for the inking unit, even if modern washing agents are used. 
     SUMMARY OF THE INVENTION 
     According to the present invention, the above object can be achieved in that a doctor-blade device is preferably provided at a distributor roller of the arrangement of rollers which supply the ink flow before the ink flow is split, and that a further doctor-blade device is provided at, at least, one distributor roller of the last ink rollers, seen in direction of rotation of the plate cylinder. By virtue of this arrangement, the ink residues which have been dissolved by the washing agent can be wiped off in an essentially shorter time and the inking unit can be cleaned uniformly, even if washing agents based on vegetable oil, the evaporation of which takes longer, are used. 
     In summary, one aspect of the invention resides broadly in a printing press comprising: a frame; a plate cylinder being rotatably mounted on said frame; an ink reservoir for holding a supply of ink; an inking mechanism for transferring the ink between said ink reservoir and said plate cylinder during operation of said printing press; said inking mechanism comprising a plurality of inking rollers, at least one ink fountain roller and at least one transfer means for transferring ink between said ink fountain roller and at least one of said plurality of inking rollers; a plurality of ink applicator rollers for being engaged with said plate cylinder and for applying ink to said plate cylinder; said plurality of ink applicator rollers comprising a first set of at least one ink applicator roller and a second set of at least one ink applicator roller; said plurality of inking rollers comprising a roller arrangement, said roller arrangement comprising a first set of at least one inking roller and a second set of at least one inking roller; said plurality of inking roller further comprising a third set of at least one inking roller; said first set of at least one inking roller for providing ink to said first set of at least one ink applicator roller; said second set of at least one inking roller for providing ink to said second set of at least one ink applicator roller; bridge roller means being engaged with: at least one inking roller of said first set of at least one inking roller; and at least one inking roller of said second set of at least one inking roller; said third set of at least one inking roller extending between said at least one transfer means and said bridge roller means; said third set of at least one inking roller for providing a primary stream of ink to said bridge roller means, said bridge roller means being engaged with at least one inking roller of said third set of at least one inking roller; said bridge roller means for dividing said primary stream of ink and thence providing a first subsidiary stream of ink to said first set of at least one inking roller and a second subsidiary stream of ink to said second set of at least one inking roller; means for washing said plurality of inking rollers, said washing means comprising: means for supplying washing fluid to said plurality of inking rollers, said washing fluid for being propagated among said plurality of inking rollers to wash said plurality of inking rollers; first removing means, for removing propagated washing fluid directly from one inking roller of said third set of at least one inking roller; and second removing means, for removing propagated washing fluid directly from one inking roller of said roller arrangement. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     A specimen embodiment of the invention is schematically illustrated in the drawings, wherein: 
     FIG. 1 shows a side elevational view of an inking unit according to the solution of the invention; and 
     FIG. 2 is essentially the same view as FIG. 1, but illustrating additional components. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In a known manner, the inking unit shown in FIG. 1 essentially comprises an ink fountain 1 having a fountain roller 2 and preferably a plurality of ink rollers 3 through 6 via which the ink flow is fed to a distributor roller 7. The ink roller 8 cooperating with the distributor roller 7 can preferably split the ink flow and transfer the ink it onto further ink rollers 9 and 10, from where, as seen in direction of rotation of the plate cylinder 11: 
     the split ink flow preferably goes onto the plate-inking rollers 12 and 13 via the roller 10; and the ink can preferably be supplied from the ink roller 9 onto the two subsequent plate-inking rollers 16 and 17 via the ink roller 14 and the distributor roller 15. 
     It should be understood that, in the context of the present invention, a &#34;distributor roller&#34; may preferably be embodied by a roller which oscillates from side to side to distribute ink or another agent more evenly across another inking roller or rollers. Such &#34;distributor rollers&#34; +are well known to those of ordinary skill in the art and, as such, will not be described in further detail herein. 
     An advantage of the present invention is realized by assigning, for example, a respective device 18, 19 for supplying and applying the cleaning agent 20 to both the ink roller 6 and ink roller 14. 
     Thus, in other words, in accordance with a preferred embodiment of the present invention, two supplying devices 18 and 19 are preferably provided for supplying cleaning agent 20 to the rollers 3 through 15, to enable the washing of the inking rollers. Particularly, one supplying device 18 can preferably be mounted so as to supply cleaning agent 20 directly to inking roller 6, while another supplying device 19 can preferably be mounted so as to supply cleaning agent 20 directly to inking roller 14. With cleaning agent 20 having been applied to inking roller 6 and inking roller 14, several rotations of rollers 3 through 15 will generally result in the cleaning agent being propagated to essentially all of the rollers 3 through 15. 
     In accordance with a preferred embodiment of the present invention, a doctor-blade device 21, 22 is preferably assigned, respectively, to the distributor roller 7 and to the distributor roller 15. Each doctor-blade device 21, 22 preferably has a doctor blade 23, 24 by means of which the soiled cleaning agent can preferably be wiped off from the outer cylindrical surface of the respective distributor roller 7 or 15. The wiped-off agent can then preferably be collected in a vessel 25, 26 from where the wiped-off agent can be removed. Via a cam shaft 27, assigned to preferably each of the respective collecting vessels 25, 26, the doctor blade 23, 24 attached to the respective collecting vessel 25, 26 can preferably be engaged at the outer cylindrical surface of the respective distributor rollers 7, 15 and disengaged therefrom upon completion of the cleaning process. 
     Thus, in other words, in accordance with a preferred embodiment of the present invention, two doctor-blade arrangements 21, 22 are preferably provided for removing soiled cleaning agent off from distributor roller 7 and distributor roller 15, respectively. Each doctor-blade arrangement 21, 22 preferably includes a doctor blade 23, 24 for scraping, or wiping, soiled cleaning agent from the respective distributor roller 7, 15. Alternatively, instead of a single doctor blade extending across a length of each distributor roller 7, 15, each doctor-blade arrangement may conceivably include several adjacent doctor blades across a substantial portion of the respective distributor roller 7, 15. 
     FIG. 2 illustrates a printing press frame 30, on which the various rollers and cylinders of the printing press according to the present invention may preferably be mounted. Also shown in FIG. 2 is a vibrator roller 32, positioned between ink fountain 1 and inking roller 3 and actuators 34 and 36 for doctor-blade devices 21 and 22, respectively. Each actuator 34, 36 can preferably be configured for selectively engaging and disengaging each respective doctor blade 23, 24 with respect to corresponding distributor rollers 7 and 15, respectively. A control arrangement 38 can also preferably be provided for controlling the engagement and disengagement of doctor blades 23, 24 via the respective actuators 34, 36. Control arrangement 38 may preferably be configured to coordinate the engagement and disengagement of doctor blades 23, 24 via the respective actuators 34, 36 when a washing operation is performed. Thus, it is conceivable, by means of control arrangement 38, to provide for simultaneously applying doctor blades 23, 24 to the surfaces of respective distributor rollers 7 and 15, or to do so in staggered fashion, whichever is desired. 
     One feature of the invention resides broadly in the device for washing an inking unit provided at a printing machine comprising at least one device for supplying the cleaning agent and a device for wiping off the cleaning agent, soiled by ink residues, from an inking-unit roller, characterized in that a doctor-blade device 21 is provided at a distributor roller 7 of the arrangement of rollers 3 through 7 for the purpose of supplying the ink flow before being split, and that a further doctor-blade device 22 is provided at, at least, one distributor roller 15 of the last ink roller 14, 16, 17, seen in direction of rotation of the plate cylinder 11. 
     Examples of general components for printing presses, which may be utilized in accordance with the embodiments of the present invention, may be found in the following U.S. Patents: U.S. Pat. No. 5,010,820, which issued to Loffler on Apr. 30, 1991; and U.S. Pat. No. 5,081,926, which issued to Rodi on Jan. 21, 1992. 
     Examples of washing apparatus for a printing press, and components thereof, which may be utilized in accordance with the embodiments of the present invention, may be found in the following U.S. Patents: U.S. Pat. No. 5,174,209, which issued to Rodi et al. on Dec. 29, 1992; and U.S. Pat. No. 5,174,210, which issued to Rodi et al. on Dec. 29, 1992. 
     All, or substantially all, of the components and methods of the various embodiments may be used with at least one embodiment or all of the embodiments, if any, described herein. 
     All of the patents, patent applications and publications recited herein, if any, are hereby incorporated by reference as if set forth in their entirety herein. 
     The details in the patents, patent applications and publications may be considered to be incorporable, at applicant&#39;s option, into the claims during prosecution as further limitations in the claims to patentably distinguish any amended claims from any applied prior art. 
     The invention as described hereinabove in the context of the preferred embodiments is not to be taken as limited to all of the provided details thereof, since modifications and variations thereof may be made without departing from the spirit and scope of the invention.