Abstract:
A folder for a printing press includes a cutting cylinder assembly having at least two knife and anvil cylinder sets positioned near the cutting region of a folder. The cutting cylinder assembly slides or actuates one of the knife and anvil cylinder sets into a cutting position for a desired cut length. The web passes between the knife and anvil cylinder set and is cut. When the cut length needs to be changed, the assembly is relocated to such a position that a second or further set of knife and anvil cylinders is aligned with the web.

Description:
[0001]    This application claims priority to U.S. Provisional Application Ser. No. 61,625,429, filed Apr. 17, 2012, the entire disclosure of which is hereby incorporated by reference. 
         [0002]    The present invention relates generally to printing press equipment and more particularly to cutting devices and cutting folders. 
     
    
     BACKGROUND 
       [0003]    U.S. Pat. No. 5,865,082, hereby incorporated by reference herein, discloses a first conveyor assembly and a second conveyor assembly. Cooperating cutting cylinders having a knife and an anvil are integrated into paths of the conveying elements of the first and second conveyor assemblies, seizing a web of material prior to a cutting operation. 
         [0004]    U.S. Pat. No. 6,684,746, hereby incorporated by reference herein, discloses cutting a web by linearly moving a plurality of cutting elements in a same direction as web in a signature formation area and cutting the web with the cutting elements to form signatures. A length of the signatures is varied by varying the spacing between the cutting elements in the signature formation area. 
         [0005]    U.S. Pat. No. 8,104,755, hereby incorporated by reference herein, discloses an adjustable delivery web conversion apparatus. A variable cutoff printing unit prints pages on a web is slit into ribbons. A cutting apparatus cuts the ribbons into signatures. A controller controls the cutting apparatus based on the printing by the variable cutoff printing unit so the pages are properly positioned on the signatures. 
       SUMMARY OF THE INVENTION 
       [0006]    Typically, individual products have dedicated folder deliveries which accommodate the characteristics of the associated products. Other deliveries accommodate variable cut lengths of products by increasing the speed of the cutting cylinders relative to the web in order to shorten the length of the product or decreasing the speed of the cutting cylinders relative to the web in order to increase the length of the product. However, the speed of the knife blades on the cutting cylinder may cause performance issues and product damage. 
         [0007]    In the past, discrete cut length changes may have been done by removing and replacing the cutting cylinder cassette assembly. This is a very time consuming process that may take a day to change. Damage may also occur while removing or installing the cassette assembly. 
         [0008]    An object of the present invention provides discrete cut length changes of a product by sliding cutting cylinders sets of different diameters and/or knife arrangements into and out of the web path in a folder. This allows the production of 203 mm, 244 mm and 305 mm products from a 1220 mm blanket circumference. 
         [0009]    Another object of the present invention provides cutting cylinder sets which can change speeds relative to the web in order to produce discrete sizes within a 10 mm range. For example, product lengths varying between 305 mm and 315 mm may be cut by rotating the 315 mm size cutting cylinder set faster relative to the web speed. 
         [0010]    The present invention provides a folder for a printing press including: a cutting cylinder assembly having at least two knife and anvil cylinder sets positioned near the cutting region of a folder. The cutting cylinder assembly slides or actuates one of the knife and anvil cylinder sets into a cutting position for a desired cut length. The web passes between the knife and anvil cylinder set and is cut. When the cut length needs to be changed, the assembly is relocated to such a position that a second or further set of knife and anvil cylinders is aligned with the web. 
         [0011]    In accordance with a first embodiment of the present invention, a folder for a printing press is provided. The folder includes a movable assembly which includes a first cutting cylinder pair including a first knife cylinder and a first anvil cylinder for cutting a web into signatures, and a second cutting cylinder pair including a second knife cylinder and a second anvil cylinder for cutting the web into signatures. The movable assembly supports the first cutting cylinder pair and second cutting cylinder pair, and the assembly is movable to selectively position either the first cutting cylinder pair or the second cutting cylinder pair into a cutting position for cutting the web. 
         [0012]    The aforementioned embodiment may also include other optional components and features. For example, the following features may be included, in any combination: 
         [0013]    In accordance with a further aspect of the first embodiment, the movable assembly maybe movable perpendicular to a transport path of the web. The folder may include one or more rails, and wherein the movable assembly is movable perpendicular to a transport path of the web on the one or more rails. Alternatively, a linear bearing or bushing may be provided, wherein the movable assembly is movable perpendicular to a transport path of the web via the linear bearing or bushing. 
         [0014]    In accordance with another aspect of the first embodiment, an actuator is coupled to the movable assembly, the actuator moving the movable assembly to selectively position either the first cutting cylinder pair or the second cutting cylinder pair into a cutting position for cutting the web. The actuator may, for example, be one of a hydraulic actuator, a pneumatic actuator, and a motor. 
         [0015]    In accordance with another aspect of the first embodiment, a former, provided upstream of the movable assembly, is arranged to impart a longitudinal fold to a web. A plurality of guide belts is provided downstream of the movable assembly, the plurality of guide belts are arranged to receive the cut web from the movable assembly, and the moveable assembly is movable perpendicular to a web path of the web. 
         [0016]    In accordance with another aspect of the first embodiment, the first knife cylinder includes a first, second, third and fourth knife box positions, the first and third knife box positions equally spaced apart from each other around a circumference of the first knife cylinder. The first, second, and fourth knife box positions are equally spaced apart from each other around the circumference. 
         [0017]    The first anvil cylinder may include a first, second, third and fourth anvil positions, the first and third anvil positions equally spaced apart from each other around a circumference of the first anvil cylinder, and the first, second, and fourth anvil positions equally spaced apart from each other around the circumference. The second knife cylinder may include a first knife box and a second knife box equally spaced apart from each other around a circumference of the second knife cylinder, and the second anvil cylinder may include a first anvil and a second anvil equally spaced apart from each other around a circumference of the second anvil cylinder The first and third knife box positions may each have removably secured therein a knife box, and the first and third anvil positions may each have removably secured therein an anvil, so that the first cutting cylinder pair provides four cuts for each revolution of a plate cylinder of the printing press. In order to provide six cuts for each revolution of a plate cylinder of the printing press, the first, second and fourth knife box positions may each have removably secured therein a knife box, and the first, second and fourth anvil positions may each have removably secured therein an anvil. A filler piece can be provided in anvil or knife box positions when no anvil or knife box is present. 
         [0018]    In accordance with a second embodiment of the present invention, a method of cutting a web into variable length signatures is provided which includes the steps of: (a) supporting a first cutting cylinder pair and a second cutting cylinder pair with an assembly; (b) positioning either the first cutting cylinder pair or second cutting cylinder pair into a cutting position with respect to the web; (c) cutting the web into signatures using the positioned cylinder pair; (d) repositioning the first and/or second cylinder pairs so the other cutting pair is in a cutting position with respect to the web; and (e) cutting the web into signatures using the other positioned cylinder pair. 
         [0019]    The aforementioned embodiment may also include other optional steps. For example, the following additional steps may be included: 
         [0020]    In accordance with another aspect of the second embodiment, the step of positioning includes moving the assembly perpendicular to a transport path of the web. 
         [0021]    In accordance with another aspect of the second embodiment, the step of cutting the web into signatures using the positioned cylinder pair includes providing four cuts per revolution of a plate cylinder of a printing press located upstream of the assembly. 
         [0022]    In accordance with another aspect of the second embodiment the step of cutting the web into signatures using the positioned cylinder pair includes providing six cuts per revolution of a plate cylinder of a printing press located upstream of the assembly. 
         [0023]    In accordance with another aspect of the second embodiment, the step of cutting the web into signatures using the other positioned cylinder pair includes providing five cuts per revolution of the plate cylinder of the printing press located upstream of the assembly. 
         [0024]    In accordance with another aspect of the second embodiment, the method comprises, after either step (c) or step (e): (f) cutting the web into signatures using the positioned cylinder pair, the positioned cylinder pair providing six cuts per revolution of the plate cylinder of the printing press located upstream of the assembly. 
         [0025]    Further, the first knife cylinder may include a first, second, third and fourth knife box positions, where the first and third knife box positions are equally spaced apart from each other around a circumference of the first knife cylinder, and the first, second, and fourth knife box positions are equally spaced apart from each other around the circumference. During step (c), the first and third knife box positions each have removably secured therein a knife box and before step (f), the method may include removing the knife box from the third knife position, and removably securing in each of the second and fourth knife positions a respective knife box. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]    The invention will be better understood from a reading of the following description, given purely by way of example, with reference to the appended drawings, in which: 
           [0027]      FIG. 1  shows a schematic representation of a printing press including a cutting folder according to the present invention. 
           [0028]      FIG. 2   a  illustrates the cutting assembly of the folder of  FIG. 1  configured to provide 4 or 5 cuts per plate cylinder revolution 
           [0029]      FIG. 2   b  illustrates the cutting assembly of the folder of  FIG. 1  configured to provide 6 or 5 cuts per plate cylinder revolution. 
       
    
    
     DETAILED DESCRIPTION 
       [0030]      FIG. 1  shows a schematic representation of a printing press including a folder in accordance with the present invention. Printing press  100  may be, for example, a four color web offset printing press. Printing units  112  may each include two print couples, each couple including a plate cylinder  113  and a blanket cylinder  114 . Each couple prints on either side of a web  101 . Each print unit  112  may print a different a color, for example, magenta, cyan, yellow or black. 
         [0031]    After printing, web  101  may be slit into a plurality of ribbons by a slitter  116 , if desired. The ribbons may be combined and transported to a former  120  for longitudinal folding. The former fold  122  is in line with a direction of travel A of web  101 . Printing press  100  may include a folder  110  for folding, cutting and processing web  101  into signatures  102 . Folder  110  may be a pinless former folder, for example. 
         [0032]    Folded web  101  may be transported through a plurality of nip rolls  130  to a cutting section  128  of folder  110 . Cutting section  128  may include an assembly  140  supporting two pairs of cutting cylinders  136 ,  146 . Each cutting cylinder pair  136 ,  146  includes a respective knife cylinder  132 ,  142  and a corresponding anvil cylinder  134 ,  144 . The assembly  140  is positioned with respect to web  101  so either first cutting cylinder pair  136  or second cutting cylinder pair  146  is in a cutting position with respect to web  101 . As shown in  FIG. 1 , first cutting cylinder pair  136  is in position with respect to web  101 . The dashed line outlines a second position of assembly  140  which would align second cutting cylinder pair  146  into a cutting position with respect to web  101 . 
         [0033]    Web  101  is then cut by cutting cylinder pair  136 . Cutting cylinder pair  136  may include, for example, three knives and cut web  101  into signatures have a length of 203.33 mm each. Second knife cylinder  142  may have a different diameter than first cutting cylinder  132  and may include two or three knives, for example. Anvil cylinders  134 ,  144  include cutting rubbers for the knives to cut against. 
         [0034]    Knife cylinders  132 ,  142  may be designed to accommodate a number of knives. For example, knife cylinders  132 ,  142  may include four knife box positions. However, for a specific cutting job, only two knife box positions may include knives. The other two knife box positions may include a filler piece. For a subsequent cutting job, one or both of the filler pieces may be removed and additional knives may be installed. Thus, knife cylinders  132 ,  142  may support two equally spaced knives or three equally spaced knives for example. 
         [0035]    For example, referring to  FIG. 1 , cutting cylinder pair  136  may be configured to provide an even number of cuts per plate cylinder revolution whereas cutting cylinder pair  146  may be configured to provide an odd number of cuts per plate cylinder revolution. Further, cylinder pair  136  may be configured with different numbers of cutting knives/anvil rubbers to provide further variability. For example, cutting cylinder  132  may be configured to hold 2 knife boxes equally spaced apart around the cutting cylinder circumference to provide 4 cuts per plate cylinder revolution, and may be configured to hold 3 knife boxes equally spaced apart around the cutting cylinder circumference to provide 6 cuts per plate cylinder revolution. Cutting cylinder pair  146  may be configured to provide 5 cut per plate cylinder revolution. 
         [0036]      FIGS. 2(   a ) and  2 ( b ) shows cutting cylinder pair  136  configured to provide 4 cuts per plate cylinder revolution and 6 cuts per plate cylinder revolution respectively. Cutting cylinder pair  146  provides 5 cuts per plate cylinder revolution. Cutting cylinder  132  of cylinder pair  136  has four knife box positions  232 ,  332 ,  432 , and  532  which can each be configured to hold a knife box  500  or a filler piece  600 . Anvil cylinder  134  includes four anvil rubber positions  234 ,  334 ,  434 ,  534 , which can each be configured to hold an anvil rubber  700  or a filler piece  600 ′. Knife box positions  232 ,  332 , and  532  are equally spaced apart from each other around the cylinder circumference. Moreover, knife box positions  232 ,  432  are equally spaced apart from each other around the cylinder circumference. Knife boxes  500  and filler pieces  600  can be removably secured to the cylinder  132  at positions  232 ,  332 ,  432 , and  532 . Anvil rubbers  700  and filler pieces  600 ′ can be removably secured to the cylinder  134  at positions  234 ,  334 ,  434 , and  534 . 
         [0037]    Cutting cylinder  142  of cylinder pair  146  has two knife box positions  242 ,  342  equally spaced apart around the cylinder circumference, each holding a knife box  500 . Anvil cylinder  144  includes two anvil rubber positions  244 ,  344  equally spaced apart around the cylinder circumference, each holding an anvil rubber  700 . Knife boxes  500  can be permanently or removably secured to the cylinder  142  at positions  242 ,  342 . Anvil rubbers  700  can be permanently or removably secured to the cylinder  144  at positions  244 ,  344 . The aforementioned components can be removed and secured with fasteners or in any known or desired manner. 
         [0038]    In  FIG. 2(   a ), cutting cylinder  132  has been configured to includes knife boxes  500  in knife box positions  232  and  432  to provide two knife boxes equally spaced apart around the cylinder circumference. Anvil cylinder  134  have similarly be configured each include two anvil rubbers  700  in anvil rubber positions  234  and  334 . Although anvils  700  are typically made of natural or synthetic rubber, and are thus referred to in the art as “anvil rubbers”, and that convention is used herein for convenience, any suitable material can be used therefore. Positions  332  and  532  include filler pieces  600 , and positions  334  and  534  include filler pieces  600 ′. Due to the difference in circumference and/or rotational speed between cylinders  132 , 134  of cylinder pair  136 , and cylinders  142 , 144  of cylinder pair  146 , cutting cylinder pair  136  will provide 4 cuts per plate cylinder revolution whereas cutting cylinder pair  146  will provide 5 cuts per plate cylinder revolution. As discussed above, assembly  140  is moveable so that either cylinder pair  136  or cylinder pair  146  can be positioned in the path of web  101  to cut the web into signatures. 
         [0039]    In  FIG. 2(   b ), cutting cylinder  136  has been configured to include knife boxes  500  in knife box positions  232 ,  432 , and  532 . To accomplish this change in configuration from  FIG. 2(   a ) to  FIG. 2(   b ): the knife box  500  is removed from knife box position  432  and replaced with a filler piece  600 ; the filler pieces  600  are removed from knife box positions  332  and  532  and replaced with knife boxes  500 ; the anvil  700  is removed from anvil position  434  and replaced with a filler piece  600 ′; and the filler pieces  600 ′ are removed from anvil positions  334  and  534  and replaced with anvils  700 . In the configuration of  FIG. 2(   b ) cutting cylinder pair  136  will provide 6 cuts per plate cylinder revolution whereas cutting cylinder pair  146  will provide 5 cuts per plate cylinder revolution. 
         [0040]    The present invention can be used with most “double around” long grain or short grain print unit sizes. It may also be used with one-around print units. Set forth in the table below are examples of product mixes that are possible for a variety of common printing press cut-offs. It should be noted that each row corresponds to a given assembly  140  with cylinders  132 ,  134 ,  142 ,  144  having sizes selected for the referenced cut-off. In other words, the cylinders  132 ,  134 ,  142 , and  144  would be manufactured in different sizes for a 610 mm cut-off than for a 630 mm cutoff. The particular sizes required for a given cut-off are a matter of simple geometry and will not be discussed herein: 
         [0000]    
       
         
               
               
             
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                   
                 TABLE 1 
               
             
             
               
                   
                   
               
               
                   
                 Spine Length by No. of 
               
               
                   
                 Cuts per Plate Rev (mm) 
               
             
          
           
               
                 Nom. Cutoff (mm) (in) 
                 Plate Circ (mm) 
                 3 
                 4 
                 5 
                 6 
               
               
                   
               
             
          
           
               
                 435 
                 870 
                 290.0 
                 217.5 
                   
                   
               
               
                 445 
                 890 
                 296.7 
                 222.5 
               
               
                 470 
                 940 
                 313.3 
                 235.0 
               
               
                 484 
                 968 
                   
                 242.0 
               
               
                 533.4 (21.0) 
                 1066.8 
                   
                 266.7 
                 213.4 
               
               
                 546.1 (21.5) 
                 1092.2 
                   
                 273.1 
                 218.4 
               
               
                 565.15 (22.25) 
                 1130.3 
                   
                 282.6 
                 226.1 
               
               
                 577.85 (22.75) 
                 1155.7 
                   
                 288.9 
                 231.1 
               
               
                 590 
                 1180 
                   
                 295.0 
                 236.0 
               
               
                 610 
                 1220 
                   
                 305.0 
                 244.0 
                 203.3 
               
               
                 620 
                 1240 
                   
                 310.0 
                 248.0 
                 206.7 
               
               
                 630 
                 1260 
                   
                 315.0 
                 252.0 
                 210.0 
               
               
                  638.35 (25.132) 
                 1276.7 
                   
                   
                 255.3 
                 212.8 
               
               
                 666.75 (26.25) 
                 1333.5 
                   
                   
                 266.7 
                 222.3 
               
               
                   
               
             
          
         
       
     
         [0041]    Accordingly, for a nominal cutoff of 435 mm, an apparatus according to the present invention could generate 3 cuts per plate cylinder rotation to provide 290 mm signatures with cylinder pair  146  and  4  cuts per plate cylinder rotation to provide 217.5 mm signatures with cylinder pair  136  configured as show in  FIG. 2(   a ). For a nominal cut-off of 610 mm, an apparatus constructed according to the present invention could generate 5 cuts per plate cylinder rotation to provide 244 mm signatures with cylinder pair  146 , and  4  cuts per plate cylinder rotation to provide 305 mm signatures with a cylinder pair  136  configured as shown in  FIG. 2(   a ), and 6 cuts per plate cylinder rotation to provide 203.3 mm signatures with the cylinder pair  136  configured as shown in  FIG. 2(   b ). 
         [0042]    Assembly  140  may be a linear rail set, a set of V rails, or a flat track. When assembly  140  moves, a lock down is released, the movement is actuated by, for example, hydraulic cylinders. Air cylinders or motor(s) may also be used. Assembly  140  is then moved into the proper cutting position and locked into place. Other components of folder  110  or cutting section  128  may need to be temporarily repositioned or relocated in order to provide sufficient clearance for moving and repositioning assembly  140 . 
         [0043]    With regard to movement of the assembly, the assembly  140  may for example, have extendable or retractable wheels. When the assembly  140  is to be moved, the wheels extend, the assembly is moved along the rails or track under the control of a motor, hydraulic cylinder, or pneumatic cylinder. When assembly  140  is in place, the wheels retract thereby fixing the assembly in position. Locating devices, such as pin/hole combinations, can be used to ensure that the assembly is in the proper position. Linear slide mechanisms, such as linear bearings or bushings may alternatively be used. Such mechanisms would not employ the retractable wheels, and would not necessarily need locating devices. 
         [0044]    Cutting cylinder pairs  136 ,  146  may be driven independently to allow variation in the cut off length. Assembly  140  may also support the drive necessary to rotate the cylinders, for example, a gear train, a belt drive or individual motors. 
         [0045]    Tapes, for example, tapes  150  may support web  101  and signatures  102  cut therefrom. Fan cylinders  152 ,  154  may receive signatures  102  and deposit signatures  102  on conveyor  156  for further processing. Fan delivery is product length sensitive. A tail belt registers the signatures  102  against the strippers. The strippers force the signature out of the fan pocket. The signature then lands on the delivery belts  156 . Conventional mechanisms allow quick make-ready adjustments to the belt and stripper to accommodate quick changes in product length, and therefore will not be discussed herein. 
         [0046]    In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are accordingly to be regarded in an illustrative rather than a restrictive sense.