as represented in fig1 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 ( fig2 ). 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 fig3 . 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 fig4 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 . 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 ( fig5 ), 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 fig6 . it can be seen here that the engagement members 10 are displaceably seated in the guide tracks 5 . each engagement member 10 in fig6 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 fig7 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 . as represented in fig4 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 .