Abstract:
A printing tower is comprised of at least two superimposed printing groups and at least two lateral frames A distance between the two lateral frames can be varied in a horizontal direction. Each of these two lateral frames accommodates at least two of the superimposed printing groups. At least one of the two lateral frames can be moved horizontally between a functional position, in which the lateral frames adjoin each other; and an open position in which the two lateral frames are spaced apart from each other. An elevating platform is situated between the two lateral frames when they are in their open position. The elevating platform can be lowered into a bottom resting position so that the two frame sets can be moved into their closed functional position.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is the U.S. national phase, under 35 U.S.C. 371, of PCT/EP2008/060456, filed Aug. 8, 2008; published as WO 2009/043628 A2 and A3 on Apr. 9, 2009 and claiming priority to DE 10 2007 000 783.5, filed Sep. 27, 2007 and to DE 10 2007 000 604.9, filed Oct. 31, 2007, the disclosures of which are expressly incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention is directed to printing towers with at least two printing couples arranged one above the other, and is also directed to a method of operating such a printing tower. The printing tower has two side frames whose spacing distance can be changed in a horizontal direction. An elevatable lifting platform is situated between the two side frames. The lifting platform can be elevated when the side frames are moved apart horizontally and can be lowered before the side frames are moved back to their closed, functional position. A safety device is usable to form a boundary around a passage space between the side frames when they are in the open, horizontally spaced position. 
       BACKGROUND OF THE INVENTION 
       [0003]    A printing tower, with at least two printing couples which are arranged one above the other, is known from WO 2004/080718 A1. This printing tower has at least one lifting platform which is usable for transporting operating technicians to different heights in the printing tower. These correspond to the different heights at which printing couples are arranged in the printing tower. 
         [0004]    DE 198 33 468 A1 discloses a printing tower with two frame halves that can be separated horizontally from one another. When the printing tower is in this separated, horizontally opened state, a working platform, which can be raised and lowered, is situated between the halves of the frame. This prior art documents provides no details as to the location of the working platform, especially when the frame is closed. 
         [0005]    A printing tower, with multiple printing couples arranged one above the other, is known from DE 94 21 112 U1. The printing couples are mounted in side frames, which side frames can be displaced, relative to one another, in a horizontal direction. 
         [0006]    US 2004/0182271 A1 describes a printing press with a lifting platform that can be moved between the side frames. 
       SUMMARY OF THE INVENTION 
       [0007]    The object of the present invention is to provide printing towers each having at least two printing couples which are arranged one above the other, and to provide a method of operating such printing towers. 
         [0008]    The object is attained according to the present invention by providing a printing tower having at least two printing couples arranged one above the other. The printing tower is comprised of at least two side frames or side frame assemblies which are separable horizontally. Each such side frame assembly accommodates at least two of the vertically spaced printing couples. An elevatable lifting platform is situated between the horizontally separable side frame assemblies and can be elevated when the side frame assemblies are spaced horizontally apart. The lifting platform can be lowered to allow the side frame assemblies to be moved together into their closed, functional position. A safety device is usable to form a boundary around a passable space between the side frame assemblies when they are in their open position. 
         [0009]    A printing tower is provided with at least two printing couples that are arranged one above the other and with at least one lifting platform. The lifting platform is preferably usable for transporting operating technicians to different heights corresponding to the different heights at which the vertically arranged printing couples are arranged the printing tower is equipped with at least two side frames or side frame assemblies, the distance between which can be adjusted in a horizontal direction. Each such side frame assembly can accommodate at least two printing couples which are arranged vertically one above the other, or can accommodate parts of at least two such printing couples arranged one above the other, such as, for example, plate cylinders and/or transfer cylinders and/or inking units and/or dampening units. At least one of the side frames or side frame assemblies can be moved generally horizontally between a functional position, in which the side frames adjoin one another, and an opened position, in which they are spaced from one another. One of the lifting platforms is arranged between the two side frames and is elevatable when they have been moved to their opened position. 
         [0010]    The benefits to be achieved in accordance with the present invention consist especially in that the side frames, which are provided with adjustable spacing, enable particularly good access to the parts of the printing couples that are typically located in the interior of the printing tower, thus making maintenance and inspection work easy to perform and to supervise. With the lifting platform arranged between the side frames in the opened position, maintenance and inspection work on the interior of the printing tower can be performed ergonomically and efficiently. Operating personnel can use the elevatable lifting platform to easily access the upper components of the vertically stacked printing couples. 
         [0011]    In accordance with the present invention the configuration of the printing tower and of the lifting platform is simple. This is especially true since the lifting platform does not need to be moved, except for its vertical lifting motion. The lifting platform remains recessed between the side frames when not in use. In an uncomplicated manner, the idle position of the lifting platform is located below the movable side frames. This idle position of the lifting platform is especially at least below the bottom transfer cylinder, and advantageously is below the bottom transfer cylinder and the bottom forme cylinder. 
         [0012]    In an alternative or supplementary embodiment of the present invention, a safety device, and preferably a guard rail section, is provided for use in for enhancing the safety of personnel. This guard rail section is preferably arranged between the two side frames or side frame assemblies which are movable in relation to one another. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    A preferred embodiment of the present invention is represented in the accompanying set of drawings and will be specified in greater detail in what follows. The drawings show: 
           [0014]      FIG. 1  a schematic side elevation representation of a printing tower with side frames, the distance between which can be adjusted in a horizontal direction, in a functional position from a side view, with a lifting platform, which is depicted in dashed lines, being arranged between the two side frames and being elevatable when the two in their opened position; 
           [0015]      FIG. 2  a schematic side elevation representation of the printing tower of  FIG. 1 , simplified such that inking and dampening units, and plate and transfer cylinders of the printing couples, are not shown; 
           [0016]      FIG. 3  the printing tower of  FIG. 2  with the side frame assemblies separated horizontally and with the lifting platform depicted schematically in its lower, idle position; 
           [0017]      FIG. 4  a perspective representation of the printing tower of  FIG. 3 ; 
           [0018]      FIG. 5  a schematic side elevation representation of the printing tower of  FIG. 3  with the lifting platform shown in a raised, working position; 
           [0019]      FIG. 6  a perspective representation of the printing tower of  FIG. 5 ; 
           [0020]      FIG. 7  a schematic side elevation view of a lifting platform configured as a scissor lift, and arranged between the two side frames, which are not specifically shown, and which are in their opened position; 
           [0021]      FIG. 8  an exploded, perspective view of the lifting platform of  FIG. 7 ; 
           [0022]      FIG. 9  a schematic side view of a lifting platform which is configured as an elevator, and which is arranged between the two side frames, which are in their opened position. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0023]    A printing tower  01  in accordance with the present invention, which is shown from a side elevation view in  FIG. 1 , consists substantially of two side frames or two side frame assemblies  11 ;  12 , a spacing distance between which two side frames or side frame assembles  11 ;  12  can be adjusted in a horizontal direction. Each printing tower is depicted as accommodating four printing couples  03  or  04 , respectively or parts thereof, and arranged one above the other. Each of the printing couples is typically configured including cooperating components such as forme cylinders  02 ;  14 , and especially plate cylinders  02 ;  14 , transfer cylinders  05 ;  06  and dampening and/or inking units  07 ;  08 . One side frame or side frame assembly  12  can be moved between a functional position, as depicted in  FIG. 1 , in which the side frames  11 ;  12  adjoin one another, and an opened position, in which the side frames or side frame assemblies  11 ;  12  are spaced from one another, as seen, for example in  FIG. 3 . In the opened position, a passable intermediate space is formed between the two side frames or side frame assemblies  11 ;  12 . 
         [0024]    A lifting platform  09 ;  10  is preferably provided on each of the two exterior sides of the printing tower  01 . Each such exterior lifting platform  09 ;  10  is usable for transporting operating technicians to different heights of the exterior sides of the printing tower  01 , with those different exterior heights corresponding to the different heights at which printing couples  03 ;  04  are arranged. Another, interior lifting platform  13  is provided, which interior lifting platform  13  is arranged between the two side frames  11 ;  12  when these two side frames  11 ;  12  are in the horizontally spaced, opened position as depicted schematically in  FIG. 3 . All of the lifting platforms  09 ;  10 ;  13  enable optimal servicing, such as the installation of plates and the performance of maintenance and cleaning work, to be performed from an ergonomic position. 
         [0025]    The printing tower  01  is configured as a 4-couple printing tower or as an 8-couple printing tower, as depicted in  FIG. 1 , and typically operates using an offset printing process. The printing couples  03 ;  04  of the printing tower  01 , each of which are arranged one above the other, are embodied as blanket-to-blanket printing couples  46 . The printing tower  01  can be opened up to the configuration shown in  FIG. 3  by the provision of the side frames or side frame assemblies  11 ;  12  being supported for movement to accomplish adjustable spacing, substantially along at least the plane in which the transfer cylinders  05 ;  06  of the blanket-to-blanket printing couples  46  are in contact with one another. The printing tower  01 , which is intended primarily for newspaper printing, is four printing formes in width, and is preferably configured as a 4/2 printing unit. The printing tower  01  can also be six printing formes in width, in which case it is preferably configured as a 6/2 printing unit. It is also possible for the printing tower to be configured as a 4/1 or as a 5/2 printing unit. 
         [0026]    In each side frame or side frame assembly  11 ;  12 , multiple, and preferably 4, printing couples  03 ;  04  are arranged one above the other. Each printing couple  03 ;  04  preferably has at least one forme cylinder  02 ;  14 , one transfer cylinder  05 ;  06  and one inking unit  07 ;  08 . A dampening unit may also be provided for each such printing couple. Every two cooperating printing couples  03 ;  04 , which are situated opposite to one another horizontally, form a blanket-to-blanket printing couple  46  which prints both sides of a web simultaneously. 
         [0027]    The arrangement of the interior lifting platform  13 , which is situated between the two side frames or side frame assemblies  11 ;  12  when these two side frame assemblies  11 ;  12  are in the opened position depicted in  FIG. 3 , will be described in detail in reference to  FIG. 2  through  FIG. 5 . The printing tower  01 , with the interior lifting platform  13 , is illustrated, simplified in  FIGS. 2 through 5  to the extent that inking units  07 ;  08  and/or dampening units, and plate cylinders  02 ;  14  and transfer cylinders  05 ;  06  of the printing couples  03 ;  04 , along with the lifting platforms  09 ;  10 , which are situated on the two exterior sides of the printing tower  01 , are not shown. 
         [0028]    In  FIG. 2 , the two side frames or side frame assemblies  11 ;  12 , which are configured with adjustable horizontal spacing, are in their functional position. The transfer cylinders  05 ;  06  of the cooperating printing couples  03 ;  04 , as may be seen in  FIG. 1 , are, or can be in contact with one another along a plane of contact, and especially with a web of print material, which is not specifically depicted, being situated between them. In  FIG. 3 through 6 , the two side frames or side frame assemblies  11 ;  12  with adjustable spacing are depicted in their opened position. The interior lifting platform  13  can be raised from its idle, lowered position, as seen in  FIGS. 3 and 4 , to at least one elevated, working position of a defined height, as seen in  FIG. 5  and  FIG. 6 , between the transfer cylinders  05 ;  06  of the printing couples  03 ;  04 . In the opened position of the side frame assemblies, the transfer cylinders  05 ;  06  of the printing couples  03 ;  04  are no longer in contact with one another, but are instead separated horizontally from one another. The two side frames or side frame assemblies  11 ;  12  are both arranged on a common substructure  35 . In the configuration depicted in  FIGS. 2-6 , the side frame assembly  11  is stationary in relation to the substructure  35 , while the side frame assembly  12  is movable in relation to the substructure  35 . The interior lifting platform  13  can be lowered to a bottom, idle position, in which the opened side frames or side frame assemblies  11 ;  12  can be moved to their closed, functional position depicted in  FIGS. 1 and 2 . In this closed, functional position of the printing tower  01 , the lifting platform  13  is situated in its bottom, idle position, outside of the area of motion of the movable side frame  12 . In its idle position seen in  FIG. 2 , the interior lifting platform  13  is preferably situated outside of the area of motion of the movable side frame  12  such that it is located below the movable side frame  12 . In its idle position, the interior lifting platform  13  can also preferably be situated between the two opposing side frame sections  33 ;  34  of the movable side frame assembly  12 , as seen in  FIG. 4 . The interior lifting platform  13 , in the bottom, idle position, is preferably situated below a lowest printing couple  03 ;  04 , and is especially situated below a transfer cylinder  05 ;  06  and/or a forme cylinder  02 ;  14  of a lowest printing couple  03 ;  04 . Viewed in a horizontal direction, the lifting platform  13  is stationary. In other words, it does not move along the substructure  35  in the direction of horizontal movement of the side frame assembly  12 . 
         [0029]    From a top plan view, the lifting platform  13  and the printing couple  04  and/or the transfer cylinder  06  and/or the forme cylinder  14  overlap one another in a horizontal direction. 
         [0030]    In addition, in  FIG. 2 , in which the two adjustable-spacing side frames or side frame assemblies  11 ;  12  of the printing tower  01  are in their functional position, and in  FIG. 3 through 6 , in which the two adjustable-spacing side frames or side frame assemblies  11 ;  12  of the printing tower  01  are in their horizontally opened position, at least one safety device  15 , such as, for example, a guard rail section  15 , is preferably assigned to the lifting platform  13 . Guard rail section  15  is arranged, for example, on at least one side frame or side frame assembly  11 ;  12 , as a safety measure and is usable primarily to protect operating technicians from falling off of the lifting platform  13  in its raised, working position. In the depicted configuration, the at least one guard rail section  15  is held on, and is connected at its two ends, to the two adjacent side frames or side frame assemblies  11 ;  12 . By moving the two adjacent side frames or side frame assemblies  11 ;  12  relative to one another, the at least one guard rail section  15  can be moved to its idle position, as seen in  FIG. 2 , or to its functional position, as seen in  FIG. 3  through  FIG. 6 . The at least one guard rail section  15  can thus be moved, by a relative movement of the two adjacent side frames or side frame assemblies  11 ;  12 , from an at least substantially stowed, idle position to a functional position in which it is extended in relation to the side frames. 
         [0031]    At least one safety device  15 , which is preferably configured as a guard rail section  15 , is located in the printing tower  01 , and forms a boundary around the passable intermediate space between the two side frames  11 ;  12  when the two side frames or side frame assemblies  11 ;  12  are in their opened position. The safety device  15  is situated so as to form or define a boundary around the intermediate space in the longitudinal direction of a transfer cylinder  05 ;  06 . Preferably, at least one safety device  15  is arranged on each of the two sides of the intermediate space. 
         [0032]    Each guard rail section  15  is comprised of two pin-jointed pivoting pieces  16 ;  17  which are joined to each other at their adjoining, inboard ends. Each pivoting piece  16 ;  17  of each guard rail section  15  also has an outboard end, one of which is pivotably mounted on one of the two side frames  11 , while the other of which is pivotably mounted on the other of the two side frames  12 , all as seen in  FIG. 3  through  FIG. 6 . In principle, it is conceivable for the guard rail section  15  to be comprised of more than two of the pin-jointed pivoting pieces  16 ;  17 . The pin-jointed pivoting pieces  16 ;  17 , which form the guard rail section  15 , are embodied as rods  16 ;  17 . Two straight lines, each of which extends through the respective frame-side pivoting axis of one of the pivoting pieces  16 ;  17  and through the shared pivoting axis of the pivoting pieces  16 ;  17 , together form a downward opening angle that is smaller than 180° in both the idle position of the guard rail section  15 , as depicted in  FIG. 2  and in the functional position of the guard rail section  15 , as shown in  FIGS. 3-6 . 
         [0033]    Depending upon the height of the printing tower  01 , the number of printing couples  03 ;  04  which are arranged one above the other, and the number of elevated working positions of defined height for the interior lifting platform  13 , at least two guard rail sections  15  are provided, and are arranged spaced one above the other, between the side frames or side frame assemblies  11 ;  12 . 
         [0034]    The interior lifting platform  13 , which is arranged between the side frames or side frame assemblies  11 ;  12  in their opened position, has at least one elevated working position of defined height in addition to a bottom, idle position. Accordingly, the vertical positions of the guard rails sections  15  are preferably assigned to the respective working positions of defined height. 
         [0035]    It is also conceivable, in principle, for the interior lifting platform  13  to have only one working position of a defined height. This one elevated working position of the interior lifting platform  13  can be assigned two guard rail sections  15 , which are arranged one above the other. 
         [0036]    As an additional safety measure, the interior lifting platform  13  can also be equipped with at least one emergency shut-off button. The actuation of this emergency shut-off button will halt the vertical movement of the lifting platform  13 , thereby holding the lifting platform  13  in its current position, regardless of whether this current position is a working position or an idle position, or any position between these. An emergency shut-off button can be located on one of the guard rail sections  15  or can be located on all guard rail sections  15 , and/or can be located on the lifting platform  13  itself. To protect technicians from getting caught in the machinery, a switching strip, preferably in the form of a foot-actuated switch, which is not specifically depicted, can also be mounted on the lifting platform  13 , such as, for example, around its perimeter. Such a foot-actuated switch will halt the movement of the lifting platform  13  in a manner similar to, or the same as the emergency shut-off button, for example when it is touched by a foot of the operator. Additionally, a safety plate can be arranged on the underside of the lifting platform  13 . Such a safety plate will halt the movement of the interior lifting platform  13 , similar to, or in the same manner as the emergency shut-off button, if, during lowering of the lifting platform  13 , the safety plate comes into contact with an object underneath the lifting platform  13 . Such an object could become damaged or pinned by the lifting platform  13 , or could be a person who could be injured by the continued lowering of the lifting platform  13 . 
         [0037]    The interior lifting platform  13  is preferably configured as a scissor lift  13 , as represented most clearly in  FIG. 7  and in  FIG. 8 . The scissor lift  13  preferably comprises two scissors  18 ;  19  or pairs of scissors  18 ;  19 , which are pin-jointed to one another. The scissor lift  13  further comprises a lower frame  20 , on which a first, lower arm  21  of a lower scissor  19  or a lower pair of scissors  19  is pivotably mounted. The second, other lower arm  22  of the lower scissor  19  or lower pair of scissors  19  is displaceably guided on the lower frame  20 . For this purpose, the second, other arm  22  of the lower scissor  19  or lower pair of scissors  19  is preferably equipped with track rollers  23 . The scissor lift  13  further comprises an upper frame  24 , on which a first, upper arm  25  of an upper scissor  18  or an upper pair of scissors  18  is pivotably mounted. The second, other upper arm  26  of the upper scissor  18  or the upper pair of scissors  18  is displaceably guided on the upper frame  24 . For this purpose, the second, other upper arm  26  of the upper scissor  18  or the upper pair of scissors  18  is preferably equipped with track rollers  28 . The upper frame  24  also has an upper platform  27 . 
         [0038]    At least one actuation assembly  29 , such as, for example, a cylinder  29 , is provided for use in moving the lifting platform  13 . The cylinder  29  is preferably configured as a lift cylinder  29 . The lift cylinder  29  is preferably functionally situated between two pin-jointed ends of the arms  22 ;  26  of the scissor assembly  30  of the scissor lift  13 , which scissor assembly  30  is comprised of the lower scissors  19  and the upper scissors  18  or of the scissor pairs  19  and  18 . In this case, the lift cylinder  29  is functionally arranged between the two pin-jointed arms  22 ;  26  of the two different scissors  19 ;  18  or scissor pairs  19 ;  18  of the scissor arrangement  30 . In principle, it is also conceivable for the cylinder  29  to be functionally arranged between two pin-jointed arms  21 ;  22  or  25 ;  26  of a scissor  19  or  18  or of a scissor pair  19  or  18  of the scissor assembly  30 . 
         [0039]    Preferably, a single lift cylinder  29  is provided, and is arranged centrally between the scissor pairs  18 ;  19  of the scissor assembly  30 . 
         [0040]    At least one end of the lift cylinder  29  is preferably pivotably mounted on a pivoting lever  31 , as seen in  FIG. 7 . Preferably, the lift cylinder  29  is pivotably mounted, at one end, on the lower or bottom scissor  19 , with the piston rod  32  of the lift cylinder  29 , at its opposite end, being pivotably mounted on the upper scissor  18 . In this case, the end of the piston rod  32  is preferably mounted on the pivoting lever  31 , which is, in turn, pivotably mounted on the upper scissor  18 . The at least one lift cylinder  29  is preferably embodied as a hydraulic cylinder  29 . 
         [0041]    It is important to emphasize that the exterior lifting platforms  09 ;  10  can also be embodied as scissor lifts which would be generally similar to the scissors lift assembly  30  utilized to raise and lower the interior lifting platform  13 . 
         [0042]    Each of the lifting platforms  09  and  10 , which are arranged on the exterior sides of the printing tower  01 , and the interior lifting platform  13 , which is arranged between the two side frames or side frame assemblies  11 ;  12  of the printing tower  01 , when they are in their opened position, can also be embodied as an elevator  36 , which is provided with a rack-and-pinion drive or lift cylinder drive, as is represented in  FIG. 9 , rather than as a scissor lift. Each elevator platform can be guided on a guide track  39  or between multiple guide tracks  39 . The elevator  36  depicted in  FIG. 9  has a platform  40 , the vertical movement of which platform  40  is guided by the operation of track rollers  41  that engage in one or more vertical guide tracks  39 . In the case of a rack-and-pinion drive for the elevator platform  40 , a pinion  37  of a drive motor engages in a toothed rack  38 . When the drive motor is actuated, the motor-driven pinion  37  generates a linear relative movement between the toothed rack  38  and the drive motor. All other suitable types of linear drives, such as a hydraulic cylinder which forces the platform  40  upward in the manner of a ram, are also conceivable drive options for the elevator  36 . In this case, a toothed rack  38  can assume the function of a guide track  39 , or vice versa. The at least one guide track  39  or the at least one toothed rack  38  is then preferably arranged on the stationary side frame or side frame assembly  11 . Preferably, no guide track  39  or toothed rack  38 , respectively, is arranged on the movable side frame  12 . 
         [0043]    A guard rail  42  is provided as a safety feature that is intended to prevent falls. This guard rail is provided in connection with the use of the elevator  36  as one of the lifting platforms  09  or  10  which arranged on the exterior sides of the side frames or side frame assemblies  11 ;  12 . As an additional safety measure, the elevator  36  can be equipped with at least one emergency shut-off button  45 . The actuation of such a shut-off button  45  will halt the vertical movement of the elevator  36  and will hold the elevator  36  in its current position. Such a stoppage will occur regardless of whether this current position of the elevator  36  is a working position, an idle position, or any position between these two. The emergency shut-off button  45  can be located on the guard rail  42 . In an embodiment of the elevator  36  without a guard rail  42 , particularly if the elevator  36  is to be used as a lifting platform  13  which is arranged between the two side frames or side frame assemblies  11 ;  12  in their opened position, the emergency shut-off button  45  can be located on one or on all of the guard rail sections  15 , and/or can be positioned on the elevator  36  itself. 
         [0044]    To protect technicians from getting caught in the machinery, a switching strip  43 , preferably in the form of a foot-actuated switch  43 , can be mounted on the elevator  36 , for example around its perimeter. Such a foot-actuated switch  43  will halt the movement of the elevator  36  in a manner which is similar to, or the same as the emergency shut-off button  45 , for example when touched by a foot. Additionally, a safety plate  44  can be arranged on the underside of the elevator  36 . This safety plate  44  will halt the movement of the elevator  36  in a manner which is similar to or the same as the emergency shut-off button  45 . If, during lowering of the elevator  36 , the safety plate  44  comes into contact with an object underneath the elevator  36 , such as an object that could become damaged or pinned by the elevator  36 , or a person who could be injured by the continued lowering of the elevator  36 , the safety plate  44  will stop further movement of the elevator  36 . 
         [0045]    While preferred embodiments of printing towers with at least two printing couples arranged one above the other, and a method for operating such a printing tower, in accordance with the present invention, have been set forth fully and completely hereinabove, it will become apparent to one of skill in the art that various changes in, for example the specific structure of the inking and dampening units, the nature of the web to be printed and the overall structure of a printing press in which such printing towers could be utilized, 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.