Abstract:
A method and apparatus for more simply and efficiently coupling and decoupling a cylinder in a printing machine. The coupling and decoupling apparatus includes a bearing bushing ( 11 ) in a fixed bushing ( 28 ). The bearing bushing ( 11 ) carries an axial force loaded spindle ( 10 ) that is axially displaceable within the bushing ( 11 ) between a coupling position in a centering portion ( 9 ) of the cylinder and a decoupling position in which a braking system ( 24, 25 ) is engaged.

Description:
FIELD OF THE INVENTION 
     The invention relates to a method and device for coupling and uncoupling cylinders in a printing press. 
     BACKGROUND OF THE INVENTION 
     DE 195 37 421 C1 discloses a method and apparatus for disconnecting a cylinder from a drive which includes a coupling consisting of first and second clutch disks. The first clutch disk is connected without rotational play to a drive wheel and the second clutch disk is connected without rotational play to the cylinder journal. Both clutch disks can be axially shifted with respect to each other by means of a work cylinder to which pressure can be applied. In the process, a lower pressure is applied to the work cylinder during the coupling process than the final pressure which is applied in the coupled state. The first clutch disk is connected with a control valve whereby the control valve can be actuated by the second clutch disk in such a way that during the coupling of the work cylinder, the control valve contains a pressure medium and the control valve is closed in the coupled state. 
     EP 0 714 767 A1 discloses a device for coupling a rotatary cylinder in a printing machine where a drive wheel is fixed during the removal of the cylinder. The cylinder journal of the rotatary cylinder is arranged in the frame, formed by two half-shells, in an openable bearing. The bearing is provided with a bore in a bearing bushing, where the bore is concentric with the cylinder axis. A hollow shaft rotates in the bore without play, and a control shaft that can be axially displaced is arranged in said hollow shaft where each control shaft and the associated cylinder journal are connected by means of coupling halves. On the end, the drive wheel is attached to the hollow shaft, and between the hollow shaft and the control shaft, an additional gear is arranged, with clearance, which compensates for shaft misalignment. The hollow shaft has internal teeth, and the control shaft has two external sets of teeth that cooperate with the internal teeth, and can be rotated with respect to each other. 
     DE 296 17 401 U1 discloses a device for the connection/disconnection of roller elements of a printing machine. By the axial shifting of a journal, using a tensioning spindle which passes through the roller body, the coupling of the roller and bearing is achieved. On one side, the tensioning spindle can be screwed into the first journal, and, one the other side, a tensioning screw passes through a second journal and can be screwed into the tension spindle. The roller body presents, on the front side, passage bores for receiving the journal where compression springs are arranged in the passage bores can be connected to the roller body by the actuation of the tensioning screws of both journals against the spring force. A drawback of this arrangement is that all of the embodiments are relatively expensive. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a method and apparatus which avoids the drawbacks of the prior art and which enables efficient coupling and uncoupling of cylinders and bearings, while simplifying the drive and reducing equipment installation times. 
     A first advantage of the method and apparatus of the invention is that the coupling process can be automated. As a result, a considerable reduction of installation time can be achieved in the replacement of a cylinder in a printing machine. 
     Another advantage is that the coupling and decoupling of the cylinder can be carried out rapidly and reliably and that a high rotational precision can be achieved by centering the cylinder. 
     An additional advantage is that the cylinder can be designed with or without a journal. A recess for the journals which penetrates the lateral frame is not necessary. 
     This simplifies the insertion or the replacement of the cylinder between two lateral frame walls, regardless of whether the operations are carried out manually or in automated fashion, for example, by means of a magazine and/or handling device, or industrial robots. 
     Finally, it is advantageous that a replacement of the cylinder, or alternately, of a roller, can be carried out in a manual or automated process. For example, in printing and/or coating machines, an automated replacement of the printing/coating block can be carried out, while an automated replacement of cylinders or rollers in the bearing bushings is carried out, preferably simultaneously. 
    
    
     Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings, in which: 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a partially diagrammatic side elevational view of an illustrative sheet fed fed rotary printing machine having two coating machines with cylinders with decoupling devices in accordance with the invention; 
     FIG. 2 is an enlarged vertical section of a bearing of one of the cylinders on a drive side (side A); 
     FIG. 3 is a vertical section of a bearing of a cylinder on a drive side (side B) of the machine; 
     FIG. 4 is an enlarged vertical section of a bearing with axially latching of a cylinder; 
     FIG. 5 is an enlarged vertical section of a bearing with circumferential latching of the cylinder; and 
     FIG. 6 is transverse section taken in the plane of line A—A in FIG.  5 . 
    
    
     While the invention is susceptible of various modifications and alternative constructions, certain illustrative embodiments thereof have been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now more particularly to the drawings, there is shown an illustrative sheet-fed printing machine which in this case includes several printing units  14  for multi-color printing, and two coating units  15 ,  16  which are connected downstream in the sheet travel direction  5 . 
     A sheet-fed rotary printing machine may consist of, for example, several printing units  14  for multicolor printing, and two coating units  15 ,  16 , which are connected downstage relative to the machine direction  5 . A drying system  20  is arranged between the two coating units  15 ,  16 . The last coating unit  16  is followed by a sheet delivery unit  18 , which has a circulating conveyance system  19  for transporting and depositing the sheet material on a sheet delivery stack. 
     Each printing unit  14  includes a plate cylinder  13  of single size, a rubber sheet cylinder  12  of single size, and a double size printing cylinder  1  as a sheet guide cylinder. The plate unit  13  is associated with an inking device and optionally a damping device. Each coating unit  15 ,  16  includes a form cylinder  2  of single size, and an associated cylinder  3  as ink application roller and a metering system, and it is functionally connected with a double size printing cylinder  1  as a sheet guide cylinder. 
     Between the printing units  14 , the first coating unit  15 , the drying system  20  and the second coating unit  16 , transfer cylinders  17  of double size are arranged as sheet guide cylinders. Here a printing cylinder  1  or a transfer cylinder  17 , as desired, as sheet guide cylinder  2 , is associated with the drying system  20 . In the area of the printing zones of the rubber sheet cylinder  12  and the printing cylinder  1 , as well as of the form cylinder  2  and the printing cylinder  1 , sheet guide devices  6 ,  7  which can be actuated pneumatically, are arranged before and after each printing zone, in the show flow or machine direction  5 . In the first coating unit  15 , the metering system  4  is formed by a chamber scraper  4  with a feed system and a return system for a liquid medium. The cylinder  3  is designed as a grid-like application roller  3  in the present example. In the second coating unit  16 , the metering system  3 ,  4  is formed by two cylinders, in this instance, an application roller  3  and a metering roller  4 . 
     In keeping with the invention, the illustrated roller or cylinder  3  has a centering device  9  on both ends  8 . In particular, the centering device  9  is designed in the form of a cylinder or cone. Both centering devices  9  are arranged with mirror symmetry with respect to each other so that they are aligned on the cylinder axis. As shown in FIG. 2, in the lateral machine frame  21  on one side, for example, the drive side (A side), a bearing  28  is provided, preferably a commercially available eccentric bearing. A bearing bushing  11  is arranged in the bearing  28 , which, at one end, receives the end  8  of the cylinder  3 , and to which, at the other end, a fixed drive  22 , preferably a gear wheel is attached which can be driven. A rod  31  is arranged in the bearing bushing  11 , which is aligned with the axis of the cylinder  3  and passes through the center of the bearing bushing  11 . The end of rod  31  carries, in the direction toward the end  8 , a concentrically arranged spindle sleeve  10  and, on the other end, a brake disk  25 . The spindle sleeve  10  is arranged inside the bearing bushing  11  in a linear guide  27 , preferably without clearance. In the direction toward the end  8 , the spindle sleeve  10 , at least in the region of the end of the spindle sleeve, is designed in the form of a cylinder, cone or truncated cone, which cooperates with a centering portion  9  of the cylinder  3 . It is preferred that the surface (at the least the tip surface) of the spindle sleeve  10  have a slightly cambered form to compensate for slight alignment errors and to support the centering of the cylinder  3 . 
     Inside the bearing bushing  11 , between the bushing  11  and the spindle sleeve  10 , a tensioning system  26  is arranged, for example, a spring system, preferably concentrically with respect to the rod  31 . The brake disk  25 , which is arranged on the end of the rod  31 , is a part of the brake system, which also includes a holder plate  24  and at least one, preferably several, actuation devices  23 , preferably a working cylinder that can be actuated pneumatically. Alternately, working cylinders that can be actuated hydraulically could be used. 
     The holder plate  24  fulfills two functions. On the one hand, it functions as a brake shoe for the brake disk  25 ; on the other hand, it supports actuation devices  23  which are supported on the lateral frame  21 . If the bearing  28  is in the form of an eccentric bearing, then the actuation devices  23  are supported on the bearing  28  to guarantee the pivoting motion of the eccentric bearing. In a preferred embodiment according to FIG. 2, the bearing bushing  11  is designed as a half-shell bearing open on one side. The bearing bushing  1 , in this case in the form of a half-shell bearing, receives the end  8  of the cylinder  3  and includes a locking mechanism  29  adapted to engage the cylinder  3 . 
     In one embodiment, the locking mechanism  29 , for example, in the form of a bolt, or a bolt with spherical head, or a sphere, is arranged radially with respect to the axis of the cylinder  3  on the bearing bushing  11  (in the area of the half-shell bearing), and it is form fit to the opening or bore  35  arranged radially on the end  8  to form a positive connection (FIGS. 2,  3 ). 
     In an alternative additional embodiment, the locking mechanism  29 , for example, in the form of a bolt, is arranged with its axis parallel to the axle of cylinder  3  on the bearing bushing  11 , and an opening  35  or a bore for the form-fit connection of locking mechanism  29  is arranged on each end  8  of the cylinder  3  (FIG.  4 ). 
     In a further alternative embodiment according to FIGS. 5 and 6, the locking mechanism  29  is arranged circumferentially on the bearing bushing  11  and, on each end  8  of the cylinder  3 , an opening  35 , for example, with threads or preferably in the form of a groove for the form-fit of the locking mechanism  29 , is arranged. It is preferred that the half-shell bearing of the bearing bushing  11  in this case be approximately U-shaped, and includes a plate as locking mechanism  29 . The plate, as locking mechanism  29 , engages in the opening  35 , which is designed as a circumferential groove at the opening  35  on the end  8 . Here the circumferential groove in the opening  35  presents a secant-shaped abutment surface  36  which represents a circumferential form-fit connection with the plate shaped locking mechanism  29 . 
     According to FIG. 3, in the lateral machine frame  21  of the other side, for example the B side—similar to the A side—a bearing  28  is arranged, preferably, a commercially available eccentric bearing. A bearing bushing  11  is located in the bearing  28  and receives the end  8  of the cylinder  3 , and a rod  31 , which aligned with the axis of the cylinder  3 , passes through the center, inside the bearing bushing  11 . In the direction toward the end of the cylinder  3 , the rod  31  supports, at one end, a concentrically arranged spindle sleeve  10  and, on the other end, a brake disk  25  is arranged on the rod  31 . The spindle sleeve  10  is arranged in a linear guide  27  in the bearing bushing  11  and is designed, in the direction toward the end  8 , in the form of a cylinder, cone or truncated cone. The design of the spindle sleeve  10 , in the form of a cylinder or cone/truncated cone, is formed so that cooperates with the centering portion  9  in the end  8  of the cylinder  3 . In the bearing bushing  11 , between the bushing and the spindle sleeve  10 , and preferably concentrically with respect to the rod  31 , a tensioning system  26 , for example, a spring system, is arranged. The brake disk  25 , which is arranged at the end of the rod  31 , is again a part of a brake system, which includes a holder plate  24  and at least one, preferably several, actuation devices  23 , for example, the working cylinder that can be actuated pneumatically or hydraulically. The holder plate  24  functions as a brake shoe and simultaneously carries the actuation devices  23  which are supported on the lateral machine frame  21 . 
     If the bearing  28  is designed as an eccentric bearing, then the actuation devices  23  are arranged on the bearing  28  to guarantee the pivoting motion of the eccentric bearing. The bearing bushing  11  is analogous to the bearing bushing on the A side (FIGS. 2,  4 ,  5 ,  6 ) and its above-mentioned variants which are designed with a locking mechanism  29  for the form-fit connection with the end  8  of cylinder  3 . 
     In the area of the brake disk  25  on the end of rod  31 , second drive  30  is provided as an auxiliary drive, which is coupled to a gear  33 , for example, a worm gear. The gear wheels  30  and  33  are preferably designed as a worm drive, where the auxiliary drive  30 , in the case of a bearing  28  which is designed as an eccentric bearing, is arranged on the latter so that it can be pivoted. The gear  33  is connected to a hollow shaft  32 , which is located in the drive  30 , and through which the rod  31  passes. The hollow shaft  32  includes a freewheel, which is arranged on the inside at the bearing bushing  11 . 
     It will be seen that the work procedure may be as follows: cylinder  3  and bearing bushing  11  are decoupled. 
     Before insertion of the cylinder  3 , the actuation devices  23  are actuated, where the actuation devices are preferably coupled by appropriate circuitry to a central control; the bearing bushings  11  are stopped (braked until they stop moving) by means of the brake system  23 ,  24 ,  25 , preferably with frictional connection. For this purpose, the holder plate  24  is moved by the actuation device  23  axially in the brake position (1 st  pass section). When the desired position of the bearing bushings  11  has been reached, as determined by means of a sensor or, for example, a contact cam, the actuation device  23  continues to be actuated so that the holder plate  24  can be moved by the actuation devices  23  axially in a position for decoupling (2 nd  pass section). In this process, the holder plate  24  axially moves the brake disk  25  and the rod  31  with the spindle sleeve  10  in such a way that the holding strength of the tensioning system  26  is overcome, and the spindle sleeve  10  is moved out of the centering portion  9 . In the case of the design of the bearing bushing  11  as a half-shell bearing with locking mechanism  29 , during the coupling/decoupling, the bearing bushing  11  is moved, under sensor control, by the drive  30  into a position in which the cylinder  3  is applied on the half-shell bearing of the bearing bushing  11 , and the locking mechanism  29  engages the form-fit connection with respect to the end  8 . 
     Cylinder  3  is inserted between the lateral frames  21 . The actuation devices  23  release the brake disk  25 , and the spindle sleeves  10 , which are mutually aligned and subjected to a force from the tensioning system  26  and moved axially in the centering line  9  of the front sides  8 . As a result, tension is applied to the cylinder  3 , and it is centered. Alternately, one can use, instead of the tensioning system  26  with spring force, an actuation device which can be actuated hydraulically or pneumatically, or a threaded drive, in order to generate an axially acting force. 
     To transfer the moments of inertia, the latches  29 , as a function of their design (FIGS.  2 - 6 ), have form-fit connections with the ends  8  so that they can also be disconnected. The position for coupling or decoupling cylinder  3  with the latches  29  is preferably controlled via the drive  30  which is preferably coupled by circuitry to a central control and actuated by a contact cam or by sensing means for positioning.