Abstract:
The invention relates to a device for the selective cleaning of several cylinders of the print unit of a sheet-fed printing press, which is preferably designed in a three-cylinder construction, consisting of a cleaning device which can be selectively placed against each one of the cylinders by being displaced along a guide track. It is the object of the invention to create a device which permits the cleaning of three cylinders with one cleaning arrangement, which can be produced by simple means and permits access to the cylinders. In accordance with the invention, this object is attained in that the cleaning device ( 27 ) is displaceable along a guide track ( 5 ) designed as a straight guide ( 6 ) and is embodied as a functional unit, pivotable around an axis of rotation ( 34 ).

Description:
FIELD OF THE INVENTION 
     The invention relates to a device for the selective cleaning of several cylinders of the print unit of a sheet-fed printing press, which is preferably designed in a three-cylinder construction, consisting of a cleaning device which can be selectively placed against each one of the cylinders by being displaced along a guide track. 
     BACKGROUND OF THE INVENTION 
     Such a device is known from DE 195 12 241 C2. The cleaning device is displaced on both sides in guide tracks, which extend equidistant or nearly equidistant in the sections allocated to the cylinder surfaces, and in this way it approaches the surfaces to be cleaned. A toothed arrangement, which follows the course of the guide tracks, is allocated to the latter, and drive wheels seated in the cleaning device engage the toothed arrangement. The drive wheels are driven by means of a drive mechanism allocated to the cleaning device, and the latter is allocated in this way to the cylinder which is respectively to be cleaned. 
     The production effort required for producing it, the great wear, as well as inaccuracies in the positioning of the cleaning device at the cylinders, are disadvantageous with this device. 
     A cleaning arrangement is furthermore known from DE 42 09 642 A1, wherein a cleaning device of the cloth type, known per se, is rotatably arranged around a longitudinal axis extending parallel with the cylinders and is at almost equal distances in respect to it, and which can be selectively allocated to a printing cylinder or a rubber blanket cylinder by being turned. The cleaning cloth is brought into contact with the cylinder to be cleaned by an elastic pressure element being acted upon by compressed air. The drive mechanism for turning the cleaning device is provided in the one wall of the print unit, while the actuating means for advancing the cloth are arranged in the other wall of the print unit. 
     This cleaning arrangement can only be used for cleaning two cylinders of print units in accordance with the three-cylinder construction. 
     It is furthermore disadvantageous that the cleaning device interferes with the access to the cylinders because of its arrangement on a central pivot shaft. 
     OBJECT AND SUMMARY OF THE INVENTION 
     It is the object of the invention to create a device which permits the cleaning of three cylinders with one cleaning arrangement, which can be produced by simple means and permits access to the cylinders. 
     In accordance with the invention, this object is attained by means of the characteristics of claim  1 . 
     By means of the attainment of the object in accordance with the invention it is possible to clean several cylinders with one cleaning device, wherein this device can be produced by simple means and permits access to the cylinders without it being necessary to remove the cleaning device. 
     The invention will be described in greater detail in what follows by means of an exemplary embodiment, represented in the associated drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a top view on the schematic representation of the device in accordance with the invention, 
     FIG. 2 is a sectional representation in accordance with the line A—A in FIG. 1, 
     FIG. 3 shows a cleaning device in a lateral view, 
     FIG. 4 is a representation in accordance with FIG. 2, showing the working positions of the cleaning device, 
     FIG. 5 is a schematic representation of a further embodiment, 
     FIG. 6 is a top view on the schematic representation of the device in accordance with the invention in the embodiment with service stations, 
     FIG. 7 is a sectional representation in accordance with the line A—A in FIG. 6, 
     FIG. 8 is a representation in accordance with FIG. 6, showing the work and service positions of the cleaning device. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As represented in FIG. 1, guide elements  3  and  4  have been arranged in the print unit walls  1  and  2  and are fixed in the frame. Each one of the guide elements  3  and  4  has a guide track  5  embodied as a straight guide  6 . The guide tracks  5  are arranged in the space between a plate cylinder  7 , a rubber blanket cylinder  8  and a printing cylinder  9  (FIG.  2 ). Engagement members  10  are displaceably seated in the guide tracks  5 . In the exemplary embodiment, each engagement member  10  is designed as a carriage  11 , which engages the guide track  5  with four guide rollers  12 , which are arranged on a base plate  13 . 
     The base plate  13  is provided with a bearing journal  14 , on which a toothed segment  16  is rotatably seated, for example by means of the roller bearings  15 . The toothed segment  16  engages a toothed rack  17 , arranged fixed in place on the frame. A displacement device  18  acts on one or both carriages  11 , in the exemplary embodiment the carriage  11  arranged in the guide element  4  was used. A nut  19  is arranged, fixed against relative rotation, on the carriage  11  for this purpose, and is engaged by a spindle  20 , which is seated in the guide element  4 , secured against axial displacement, by means of a bearing  21 . A drive element  22  which, for example, is designed as a chain wheel  23 , acts on the spindle  20 . The carriage  11  can be displaced by turning the chain wheel  23  and therefore the spindle  20 . 
     A coupling member  24  is connected with the toothed segment  16 . In the exemplary embodiment, the coupling member  24  is designed as a clamping ring  25 , which consists of a fixed element  25 . 1  and a movable element  25 . 2 . The fixed element  25 . 1  is arranged, fixed against relative rotation, on the toothed segment  16 , while the movable element  25 . 2  is releasably connected with the fixed element  25 . 1 , for example by means of screws  26 . 
     A cleaning device  27  of the cloth type, known per se, is represented in FIG.  3 . However, cleaning devices of different types can also be employed. The cleaning device  27  is designed as a functional unit and basically consists of two lateral walls  28 , between which a pneumatically actuable pressure element  29 , which extends over the working width, a spray tube  30 , a clean cloth reservoir  31 , a dirty cloth reservoir  32  and a cleaning cloth  33  are arranged. The supply devices for the media, as well as the means for transporting the cleaning cloth  33  from the clean cloth reservoir  31  to the dirty cloth reservoir  32 , are not represented. 
     The cleaning device  27  is designed as a functional unit, which is pivotable around an axis of rotation  34 . To this end, bearing journals  35  are provided on the lateral walls  28 , which are received by the coupling members  24  and are adjusted and fixed in place by means not represented. For this purpose the bearing journals  35  are positioned in the fixed element  25 . 1  of the clamping rings  25  and thereafter champed in place by means of the movable elements  25 . 2  and the screws  26 . 
     The individual positions of the cleaning device  27  are represented in FIG. 4 by the position of the pressure element  29 . 
     In the center position, the cleaning device  27 , and therefore the pressure element  29 , are allocated to the rubber blanket cylinder  8 . If the surface of the rubber blanket cylinder  8  is to be cleaned, the pressure element  29  is charged with compressed air in a known manner. Because of this, the cleaning cloth  33  touches the rubber blanket cylinder  8  along a wiping line R 1 , which extends parallel with the axis of rotation of the rubber blanket cylinder  8  and parallel with the axis of rotation  34  of the cleaning device  27 . A straight line G 1 , which vertically intersects the wiping line RI and the axis of rotation of the rubber blanket cylinder  8 , also intersects the axis of rotation  34  of the cleaning device  27 . 
     The cleaning cloth  33  is moistened by the spray tube  30  with cleaning fluid or water before or while it is being pressed against the surface of the rubber blanket cylinder  8 . 
     The cleaning cloth  33  is pulled off the clean cloth reservoir  31  at intervals, as a function of its degree of being soiled or of the selected cleaning program, and is conducted to the dirty cloth reservoir  32 . The drive mechanism, or the respective control devices required for this, are a part of the cleaning device  27  and are not represented. 
     Regarding the Function: 
     If it is necessary to clean the plate cylinder  7 , the engagement member  10  embodied as a carriage  11  is displaced in the guide track  5  in the direction toward the plate cylinder  7  by means of the displacement device  18 , in that the drive element  22 , and therefore the spindle  20 , are turned. In the process the toothed segment  16 , which engages the toothed rack  17  and is rotatably seated on the bearing journal  14  of the carriage  11 , is forcibly turned. The coupling member  24 , and with it the cleaning device  27 , are turned together with the toothed segment  16 . The gear ratio between the toothed rack  17  and the toothed segment  16  has been selected such, that the cleaning device  27  is turned within the path which the carriage  11  must travel so that the pressure element  29  approaches the plate cylinder  7 , in such a way that a wiping line R 2 , which extends parallel with the axis of rotation of the plate cylinder  7  and with the axis of rotation  34  of the cleaning device  27 , and which is formed when the cleaning cloth rests against the plate cylinder  7 , is vertically intersected by a straight line G 2 , which intersects the axis of rotation  34  and the axis of rotation of the plate cylinder  7  in the same way. Cleaning of the plate cylinder takes place analogously with the cleaning of the rubber blanket cylinder  8 . 
     If the printing cylinder  9  is to be cleaned, the drive element  22 , and therefore the spindle  20 , are driven in an oppositely directed rotating movement, and therefore the engagement member  10  embodied as the carriage  11  is displaced in the guide track  5  in the direction toward the printing cylinder  9 . Because of the forced turning of the toothed segment  16 , the cleaning device  27  is conducted into a position in respect to the printing cylinder  9  in which the cleaning cloth  33  guided against the printing cylinder  9  forms a wiping line R 3 . The wiping line R 3  extends parallel with the axis of rotation of the printing cylinder  9  and the axis of rotation  34  of the cleaning device  27 , and is vertically intersected by a straight line G 3 , which intersects the axis of rotation  34  and the axis of rotation of the printing cylinder  9  in the same way. It is of course also possible to couple the spindle  20 , which imparts a push movement to the engagement member  10 , with a gear  41  arranged on the engagement member  10 , which provides the cleaning device  27  with a pivot movement. 
     The bearing journal  14  is rotatably seated in the engagement member  10  for this purpose and is coupled with the power take-off member of the gear  14 . The coupling member  24 , which is used for receiving the bearing journal  35  of the cleaning device  27  (FIG.  5 ), is connected, fixed against relative rotation, with the bearing journal  14 . 
     The parameters of the spindle  20  and the gear  41  are matched to each other in such a way, that the cleaning positions at the plate cylinder  7 , the rubber blanket cylinder  8  or the printing cylinder  9  can be selectively assumed. 
     A further development of the invention is represented in FIG.  6 . It can be seen here that the engagement members  10  are displaceably seated in the guide tracks  5 . Each engagement member  10  in FIG. 6 is designed as a carriage  11 , which engages the guide track  5  with four guide rollers  12 , which are arranged on a base plate  13 . 
     The base plate  13  is provided with a bearing journal  14 , on which a gear wheel  16  is rotatably seated, for example by means of the roller bearings  15 . The gear wheel  16  engages a toothed rack  17 , arranged fixed in place on the frame. A displacement device  18  acts on one or both carriages  11 , in the exemplary embodiment the carriage  11  arranged in the guide element  4  was used. A nut  19  is arranged, fixed against relative rotation, on the carriage  11  for this purpose, which is engaged by a spindle  20 , which is seated in the guide element  4 , secured against axial displacement, by means of a bearing  21 . A drive element  22  which, for example, is designed as a chain wheel  23 , acts on the spindle  20 . The carriage  11  can be displaced by turning the chain wheel  23  and therefore the spindle  20 . 
     A coupling member  24  is connected with the gear wheel  16 . In the exemplary embodiment, the coupling member  24  is designed as a clamping ring  25 , which consists of a fixed element  25 . 1  and a movable element  25 . 2 . The fixed element  25 . 1  is arranged, fixed against relative rotation, on the gear wheel  16 , while the movable element  25 . 2  is releasably connected with the fixed element  25 . 1 , for example by means of screws  26 . 
     Working positions to be assumed by the cleaning device  27  at the plate cylinder  7 , the rubber blanket cylinder  8  and the printing cylinder  9 , as well as service positions, are represented in FIG. 7 by means of the position of the pressure element  29 , as well as the gear wheel  16 . 
     In the working position at the rubber blanket cylinder  8 , and when the pressure element  29  is charged with compressed air in the known manner, the cleaning cloth  33  is in contact with the cylinder along a wiping line R 1 , which extends parallel with the axis of rotation of the rubber blanket cylinder  8  and parallel with the axis of rotation  34  of the cleaning device  27 , wherein the axis of rotation  34  and the axis of rotation of the gear wheel  16  coincide. A straight line G 1 , which vertically intersects the wiping line R 1  and the axis of rotation of the rubber blanket cylinder  8 , intersects the axis of rotation  34  of the cleaning device  27  in the same way. 
     Analogously with this, the cleaning cloth  33  in its working position at the plate cylinder  7  touches the latter along a wiping line R 2 , which extends parallel with the axis of rotation of the plate cylinder  7  and parallel with the axis of rotation  34 . The wiping line R 2 , the axis of rotation of the plate cylinder  7  and the axis of rotation  34  are vertically intersected by a straight line G 2 . 
     In the working position at the printing cylinder  9 , the cleaning cloth  33  touches along a wiping line R 3 . The wiping line R 3  extends parallel with the axis of rotation of the printing cylinder  9  the axis of rotation  34 . The wiping line R 3 , the axis of rotation of the printing cylinder  9  and the axis of rotation  34  are vertically intersected by a straight line G 3 . 
     The mode of operation of the device is as follows: 
     As represented in FIG. 4, for cleaning the printing cylinder  9  the pressure element  29  is charged with compressed air in the working position at the printing cylinder  9 , and the cleaning cloth  33  is thereby brought into contact with the surface of the printing cylinder  9  and the cleaning cloth  33  is moistened. 
     If the rubber blanket cylinder  8  is to be cleaned, the engagement member  10  embodied as a carriage  11  is displaced in the direction toward the plate cylinder  7  by means of the displacement device  18 , in that the drive element  22 , and therefore the spindle  20 , are turned. In the process the gear wheel  16  rolls off on the toothed rack  17  without sliding, wherein the cleaning device  27  is turned via the coupling member  24 , so that the pressure element  33  follows a track curve which is embodied as an extended cycloid  36 . The extended cycloid  36  consists of a first curve element  36 . 1  and a second curve element  36 . 2 . When the pressure element  29  has reached the working position at the rubber blanket cylinder  8 , the displacement of the carriage  11  is interrupted and the cleaning cloth  33  is brought into contact with the surface of the rubber blanket cylinder  8  by means of the pressure element  29  and the surface is cleaned in the known manner. 
     If it is required to clean the plate cylinder  7 , the carriage  11  is further displaced in the direction of the plate cylinder  7  and in the process the pressure element  29 , which runs through the second curve element  36 . 2  of the extended cycloid  36 , is brought into the working position at the plate cylinder  7 , and the plate cylinder  7  is cleaned. The course of the extended cycloid  36  is determined by the position of the working position at the plate cylinder  7 , the rubber blanket cylinder  8  and the printing cylinder  9 . 
     The pressure element  29  passes through the first curve element  36 . 1  when moving the cleaning device  27  from the printing cylinder  9  to the rubber blanket cylinder  8 , or from the rubber blanket cylinder  8  to the printing cylinder  9 , while the pressure element  29  passes through the second curve element  36 . 2  when moving the cleaning device  27  to the plate cylinder  7 , or from the latter to the rubber blanket cylinder  8 . In the course of passing through the curve elements  36 . 1 ,  36 . 2 , the pressure element  29  is guided along a first service area  37  and a second service area  38 , wherein it is in a position facing away from the plate cylinder  7 , rubber blanket cylinder  8  and printing cylinder  9 . The pressure element  29 , and therefore the cleaning device  27 , are accessible in this first and second service area  37 ,  38 , so that service operations are possible without having to remove the entire cleaning device  27 . For example, the exchange of the clean cloth reservoir  31  and/or of the dirty cloth reservoir  32  can be performed without problems. 
     In the exemplary embodiment, a first service position  39  and a second service position  40  are provided, in which access to the pressure element  29 , and therefore the cleaning device  27 , is possible. It is basically possible to provide any arbitrary service position within the first service area  37  and the second service area  38  for maintenance of the cleaning device  27 .