Abstract:
A cylinder is usable for processing flat material and includes a cylindrical body, which can be rotated about a cylinder axis, and at least one group of a plurality of tools. These tools perform a working movement in relation to the cylindrical body and are coupled to first and second control levers. A fixed cam plate is followed by the first control lever of each tool. A rotating cover disk is followed by the second control lever of each tool. The cover disk comprises a plurality of congruent sectors each having at least one section with a first radius which allows that tool to accomplish its working movement. The cover disk sectors each also have at least one section with a second radius which blocks the working movement of the tool.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This U.S. patent application is the U.S. national phase, under 35 USC 371, of PCT/EP2005/051636, filed Apr. 13, 2005; published as WO 2005/102891 A1 on Nov. 3, 2005, and claiming priority to DE 10 2004 020 303.2, filed Apr. 26, 2004, the disclosures of which are expressly incorporated herein by reference. 
   FIELD OF THE INVENTION 
   The present invention is directed to cylinders for processing flat material. A cylinder body is rotatable around a cylinder axis and has at least one group of tools evenly distributed over the circumference of the cylinder body. These tools are able to perform an operating movement with respect to the cylinder body. 
   BACKGROUND OF THE INVENTION 
   Cylinders of this general type find multiple uses, particularly in the folding apparatus of a printing press, where the movable tools which are distributed over the cylinder circumference surface can be, for example, spur needle strips, grippers, folding blades, folding jaws or the like. These cylinders are accordingly referred to as spur needle cylinders, gripper cylinders, folding cylinders or folding jaw cylinders. 
   DE 101 56 194 A1 proposes to reduce the frictional wear of a cover disk tracing or follower roller by providing, in place of one control arm with two such tracing, follower or scanner rollers, two control arms, one of which supports the cam disk scanner roller, and the other of which support the cover disk scanner roller. An abrupt acceleration of the cover disk scanner roller is prevented in this prior art device in that it is maintained in steady contact with the cover roller. 
   SUMMARY OF THE INVENTION 
   The object of the present invention is directed to providing cylinders for processing flat material, wherein wear between the cover disk of the cylinder and the associated control arrangement for the cylinder is reduced. 
   In accordance with the present invention, this object is attained by the provision of a cylinder with a cylinder body that is rotatable about a cylinder axis and which has at least one group of tools which are evenly distributed over the circumference of the cylinder body. These tools are able to accomplish a working movement, with respect to the cylinder body. Control levers are provided to effect this working movement and have cam followers that engage the surface of either a stationary cam disk or a rotatable cover disk. The cover disk is rotatable with the cylinder and has a plurality of congruent sectors. Each such sector has sections of different radii. When the followers engage these sections, they either allow movement of the control lever or prevent such movement. 
   The advantages which can be obtained by the present invention lie, in particular, in that wear in the contact area between the cover disk and the control arrangement scanning it is kept low. This is accomplished without requiring a constant contact between the control arrangement and the cover disk. 
   Instead of attempting to avoid wear on the control arrangement, by keeping its scanning roller, which scans the cover roller, continuously in rotation, in accordance with the teachings of the prior art DE 101 56 194 A1, in the construction, in accordance with the present invention, a loss of contact between the control arrangement and the cover roller is permitted and is accepted. Wear is reduced by reducing the relative speed between the rotating cylinder body and the cover disk. By increasing the number of congruent sectors of the cover disk, over that which is typical in prior art structures, the difference in rotating speed between the cylinder body and the cover disk, which is required for the control of the tool movement with the desired periodicity, is clearly reduced. In a cylinder with, for example five tools, and customarily with at most three sectors, a ratio between the control speed of the cylinder and that of the cover disk of 6:5 was customarily required in connection with dual collating operations. A ratio of 12:11 results in response to doubling the number of sectors thereby, in effect, halving of the rotating speed difference. The acceleration which is encountered by a scanning roller of the control arrangement which is scanning the cover disk is therefore halved. Since wear increases more than proportionally, with respect to the occurring acceleration, the service life of the scanning or cam following roller is even more than doubled. 
   The roller for scanning or following or tracing the cover disk can be simply mounted on a common control lever, together with a roller for scanning or following or tracing the cam disk. However, in such a configuration, the roller of the cam disk always loses contact with the cam disk at the time the cover disk blocks the operating movement of the control lever. The cam disk roller is thus slowed down and must then be accelerated again. To avoid this, it is also possible to provide two control levers, one for each roller, the provision of which two control levers permits the roller of the cam disk to remain in contact with the cam disk even when the cover disk blocks the operating movement of the control lever. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A preferred embodiment of the present invention is represented in the drawings and will be described in greater detail in what follows. 
     Shown are in: 
       FIG. 1 , a perspective view of a portion of a spur needle cylinder in accordance with the present invention, in 
       FIG. 2 , an exploded perspective detailed view of the control arrangement of the present invention, with two control levers of a spur needle strip of the spur needle cylinder of  FIG. 1 , in 
       FIG. 3 , a detailed perspective view of a simplified control arrangement having one control lever and two rollers mounted thereon, in 
       FIG. 4 , a side elevation view schematically depicting relative positions of the cam and cover disks in connection with dual collation operations of a cylinder, in 
       FIG. 5 , a side elevation view schematically depicting relative positions of the cam and cover disks in connection with triple collation operations of a cylinder, in 
       FIG. 6 , a side elevation view schematically depicted relative positions of the cam and cover disks with quadruple collation operations, and in 
       FIG. 7 , a depiction of a gear for coupling the rotations of the cylinder body and the cover disk. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  shows an end section of a cylinder body  01  with three spur needle strips, only two of which are visible in  FIG. 1 . For the sake of simplicity, the cylinder body  01  has been represented here in a narrow, geometric sense. However, it is to be understood that it is possible, in actuality, to depart from the geometric closed cylinder shape of the cylinder, provided that signatures positioned on the shell face of the cylinder  01  are conveyed on a path which is shaped as a circle or as a sector of a circle. It is possible, in particular, for the shell surface of the cylinder body  01  to be constructed of a plurality of segments, which segments can be shifted with respect to each other. The tools  02 , such as, for example, the depicted spur needles  02  of the spur needle strips, can be extended out of rows of holes which are respectively arranged spaced at a circumferential distance of 120° on the shell surface of the cylinder body  01 . The spur needles  02  are extended radially out from the cylinder shell surface, through the depicted holes in order to spear signatures conveyed on the cylinder shell surface and to further transport them, on the cylinder body  01 , to a transfer gap, which is not specifically represented. During the transfer or the handing over of the signatures at the transfer gap, the spur needles  02  must be retracted into the interior of the cylinder  01 . To accomplish this purpose, the spur needles  02  in each row or group are respectively fixedly connected with a cooperating shaft  03  by the use of suitable arms, which are hidden by the shell of the cylinder body  01  in  FIG. 1 . Each of these arms is pivotably seated in two oppositely located front or end plates  04  of the cylinder body  01 . Journals  06  of the cylinder body  01 , which are connected with the front or end plates  04  of the cylinder body  01 , are rotatably seated in a lateral frame, which is not specifically represented. A stationary cam disk  07  and a rotatable cover disk  08  are provided and are arranged coaxially with respect to the journal  06 , as represented in  FIG. 1 . The stationary cam disk  07  substantially has the shape of a circular disk which is arranged concentrically with respect to the axis of rotation of the cylinder body  01 . A circumferential section  11 , such as, for example, an indentation  11 , has been formed on a circumferential face  09  of the stationary cam disk  07 . The rotatable cover disk  08  can be seen in  FIG. 1  as being constructed having four congruent 90° sectors, each of which sectors has a section  12  in the form of an arc of a circle with a large radius, a section  13  with a lesser radius, as well as inclined faces  14 , which inclined faces  14  constitute gradual transitions between the sections  12 ,  13 . 
   Each one of the three shafts  03  of the cylinder body  01  supports two control levers  16 ,  17 . Each of these two control levers  16 ,  17  respectively forms a control arrangement for use in controlling the movement of one of the spur needle strips. For the sake of clarity, the control levers  16 ,  17  are represented, in  FIG. 1 , on only one of the three shafts  03 . The first, interior, cam disk control lever  16  has a first or a cam disk follower roller  18 , which rolls off on the circumferential surface of the cam disk  07 . In an analogous manner, the second, exterior, cover disk control lever  17  has a second or a cover disk follower roller  19 , which rolls off on the circumferential surface of the cover disk  08 . The second control lever  17  is fixedly connected with the shaft  03 , while the first control lever  16  can be rotated around the shaft  03 . 
   The control levers  16 ,  17  each have a protrusion  21  or  22 , respectively on their assigned lateral flank each of which lateral flanks is facing the associated lateral flank of other control lever  16 ,  17 . A pressure spring  23 , which exerts a spring force that drives the two protrusions  21 ,  22  apart, as may be seen in  FIG. 2 , lies between the two protrusions  21 ,  22 . The torque of a second spring, which is not specifically represented, and which is housed, for example, in the cylinder body  01 , acts, via the shaft  03 , on the second control lever  17  and drives the roller  19  of the second control lever  17  against the circumferential surface of the cover disk  08 . In spite of this, in the position represented in  FIG. 1 , the roller  19  does not touch the cover disk  08 . The mutual engagement of the protrusions  21 ,  22  with each other, and the contact of roller  18  of the first control lever  16 , which simultaneously rolls off on the circumferential face  09  of cam disk  07 , prevent this. In the course of the entire revolution of the cylinder body  01 , the roller  18  is in continuous contact with the stationary cam disk  07  and because of this continuous contact, is being uniformly rotatorily driven. However, when the roller  18  enters the indentation  11  on the face  09  of the stationary cam disk  07 , this results in a movement of the spur needles  02  only if, at the same time, the cover disk roller  19  is located opposite a section  13  of the cover disk  08  which is formed with a small radius. If, as represented in  FIG. 1 , this is not the case, the roller  19  loses contact with the cover disk  08  and is slowed in its rotation until it again comes into contact with a large radius section  12  of the cover disk  08 . 
   In a perspective view, which is analogous to  FIG. 2 ,  FIG. 3  shows a simplified control arrangement. A single control lever  17 ′, which is fastened on the shaft  03 , supports two rollers  18 ′,  19 ′ for rolling off on the cam disk  07  or the cover disk  08 , respectively. The control lever  17 ′ pivots radially inward only in the situation where both rollers  18 ′,  19 ′ simultaneously pass an indentation  11  on the cam disk  11  and a section  13  of a small radius on the cover disk  08 . 
   In place of three folding blades  02 , or spur needle strips with spur needles, or grippers or folding jaws, the cylinder  01  can also have five or seven sections, and thus can have five or seven rows or groups of tools  02 , and in particular can have five or seven rows or groups of folding blades  02 , or spur needle strips with spur needles, grippers or folding jaws. 
     FIG. 4  shows two schematic side elevation views of the stationary cam disk, which is represented in dashed lines, and of the rotatable cover disk  08 , both of which are formed by four identical sectors  26 , and of the rollers  18 ,  19 , while the rollers pass the indentation  11  of the stationary cam disk  07 . In part “a” of  FIG. 4  a section  12  of large radius of the rotatable cover disk  08  supports the cover disk roller  19 . The retraction of the spur needles  02  into the cylinder body  01  and a release of the signature held on the spur needles  02  is thereby prevented, even though the cam disk roller  18  dips into the indentation. A ratio of the number of revolutions of the cylinder body  01  and of the rotatable cover disk  08  is 8:7. When the cylinder body  01  has made a complete revolution and the roller  18  again reaches the indentation  11 , the cover disk  08  has only turned by ⅞ of a revolution which, as shown in part “b” of  FIG. 4 , results in a rotary displacement of 45° of the rotatable cover disk  08  with respect to the stationary cam disk  07  in comparison to the case shown in part “a” of  FIG. 4 . Thus, in part “b” of  FIG. 4 , the indentation  11  and a section  13  of a small radius of the cover disk  08  coincide. The cover disk roller  19  thus moves radially inwardly and the spur needles  02  are retracted. 
   In connection with a control arrangement such as the one shown in  FIG. 3 , in the case of part “a” in  FIG. 4 , the contact between the roller  19 ′ and section  12  would prevent the roller  18 ′ from dipping into the depression and the retraction of the spur needles  02  would also be blocked. In the case of part “b” of  FIG. 4 , both rollers  18 ′,  19 ′ dip in their respective depressions and the spur needles  02  would be retracted. Thus, the movement of the spur needles  02  is the same in connection with the embodiment shown in  FIG. 3  as it is with the two-armed control arrangement represented in  FIG. 2 . 
   In the case of the depiction of  FIG. 5 , the ratio of the numbers of revolutions of the cylinder body  01  and the cover disk  08  is 12:11. Thus, as shown in part “c” of  FIG. 5 , the indentation  11  in the cam disk  07  and the indentation  13  in the cover disk  08  only meet at every third revolution of the cylinder body  01 . Therefore, three signatures are collated prior to every retraction of the spur needles  02 . The difference in the rotating speeds of the cylinder body  01  and the cover disk  08  is even less here than was the case of  FIG. 4 , and the wear on the roller  18  is correspondingly less. 
   As depicted in  FIG. 6 , it is possible to increase the number “p” of revolutions of the cylinder  01 , before release of the collated products, even more. However, with the angular extension of the indentation  11 , which is represented here by way of example, it is questionable whether, in the cases “a” and “c” of  FIG. 6 , the sections  12  over the entire extent of the indentation  11  could prevent the penetration of the roller  18 . The smaller the angular extension of the indentation  11 , the greater the number of possible collation processes obviously becomes. In order to make “p”-times collations possible, the angular extension of the indentation  11  must not be greater than 2π/p. 
     FIG. 7  shows a preferred embodiment of a coupling gear between the cylinder body  01 , of which only the journal  06  is schematically represented in  FIG. 7 , and the cover disk  08 . The journal  06  crosses, and is rotatably seated, in a lateral frame plate  24  and has, at its end which is facing away from the cylinder body  01 , a first hollow gear wheel  29  of a harmonic drive gear. This first hollow gear wheel  29 , and a second hollow wheel  31  mesh with a flex spline  32 . An exterior ring gear  33 , which is fixedly connected with the second hollow gear wheel  31 , meshes with a pinion gear  34 , which is part of a shaft  36 , and which shaft  36  is offset with respect to the shaft of the cylinder body  01 , which shaft  36  crosses the lateral frame plate  24  and which shaft  36  has a further pinion gear  37  on the inside of the shaft  36 . Pinion gear  37  drives a sleeve  38  which is rotatably pushed onto the journal  06  and which sleeve supports the cover disk  08 . Assuming that the wave generator  30 , which is situated in the interior of the flex spline  32 , does not rotate, and with an amount of teeth for the hollow wheel  29  being 160, with 162 teeth for the hollow wheel  31 , 81 teeth for the exterior ring gear  33 , 24 teeth for the pinion gear  34 , 22 teeth for the pinion gear  37  and 80 teeth for exterior of the sleeve  38 , a ratio of the number of revolutions of 12:11 results between the cylinder body  01  and the cover disk  08 . Because of this ratio, as assumed in connection with  FIGS. 1 to 5 , a dual collation operation; i.e. a collation and cooperative delivery of three products, can be realized. With a cover disk with six segments, a single collation operation; i.e. a collation and delivery of two products. 
   The relative position of the cover disk  08 , in relation to the several control levers  17  of the cylinder body  01 , can be adjusted by rotation of the wave generator  30  in order to assure that in the course of the passage of one of the control levers  18  in front of the indentation  11  of the cam disk  07 , the roller  19  of the control lever  17  associated with the cover disk  08  does not change from a section  12  to a section  13 , or vice versa. The wave generator  30  is maintained, fixed against relative rotation, during the collation operation. To be able to operate the cylinder  01  in a non-collation mode, it is possible to provide a coupling between the cylinder journal  06  and the sleeve  38  which coupling, when it is closed, lets the cover disk  08  rotate at the speed of the cylinder body  01 . When this coupling is closed, the wave generator  30  is permitted to rotate. 
   By the rotatory driving of the wave generator  30  at a suitable speed, it is also possible to realize different collation numbers, corresponding to the respective gear ratio between the cylinder body  01  and the cover disk  08 . For the same purpose it would also be possible to replace the gear in  FIG. 7  with a suitable control gear, wherein several switching stages are replaced in accordance with different values of p=(2, 3, . . . ∞). In general, the ratio of the numbers of revolutions of the cylinder body  01  and of the cover disk  08  should always amount to 1:1±1/(p×m), wherein “m” is the number of the sectors  26  of the cover disk  08 , and “p” is a low natural number ≧2 or ∞. In this case, “p”=∞ corresponds to the above mentioned case of non-collating operation with a rotating cover disk  08  rigidly coupled to the cylinder body  01 ; “p”=1 corresponds to the case of non-collating operation with a stationary cover disk  08 , and all other values of “p” correspond to a respective (“p”−1)—times collation operation. 
   The number “m” of the sectors  26  is at least equal to 
             n     2   +   1       ,         
i.e.
 
             m   ≥     n     2   +   1         ,         
or m is at least 4, i.e. m=≧4 and wherein “n” is the number of groups of tools distributed evenly over the cylinder body circumference.
 
   In connection with the above preferred embodiments, only spur needle strips  02  have been used as examples of tools  02  which are attached to the cylinder body  01  and which are periodically driven. However, it is to be understood that the invention can also be applied, in the same way as described above, to other periodically moved tools  02 , such as folding blades  02 , spur needle strips with spur needles, grippers, folding jaws, and the like, which are driven at a period that is a multiple of the period of rotation of the cylinder body  01 . 
   For example, the cylinder body  01 , as well as the cover disk  08 , rotate in a counterclockwise direction, as shown in  FIG. 2 . The control arrangement  16 ,  17 ,  17 ′ is embodied to be leading or extending in the direction of rotation, for example. 
   While preferred embodiments of a cylinder for processing flat material, in accordance with the present invention, have been set forth fully and completely hereinabove, it will be apparent to one of skill in the art that various changes in, for example, the specific printing press producing the material to be processed, the drive for the cylinder, 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.