Patent Publication Number: US-6666137-B2

Title: Removable ink cassette for a printing press

Description:
This application is a division of U.S. Ser. No. 09/610,981 filed Jul. 6, 2000 and now U.S. Pat. No. 6,520,082. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates generally to printing press components, and specifically to a removable ink cassette containing an ink pan and a meter roll. 
     Flexographic printing presses are used to print various images on a moving web. Such printing presses contain at least four rolls and an ink pan or tray. In a typical roll configuration, the meter or fountain roll is located above the ink pan and collects the ink(s) from the ink pan. The meter roll transfers the ink(s) to the anilox roll. The anilox roll in turn transfers the ink(s) to a textured plate roll, which contains the image to be printed onto the moving web. The plate roll contacts the first side of the moving web to transfer the image to the first side of the web. An impression cylinder contacts the second side of the moving web to press the web against the plate cylinder. 
     However, the present inventors have realized that the prior art flexographic printing presses suffer from the following disadvantages. The-ink pan, the meter roll and anilox roll in these printing presses are contained as separate elements in a housing, which is permanently attached to the printing press frame. These permanent housings sometimes require special tools to remove the ink pan and the meter roll from the printing press. Furthermore, in order to remove the ink pan from the printing press for cleaning and ink changing, the press operator first has to separately remove the anilox roll from the printing press and then remove the meter roll from the ink pan before removing the ink pan from the printing press. The separate roll removal steps lead to an increased down time for the printing press while the ink pan is being removed for cleaning. The present invention is directed to overcoming or at least reducing the problems set forth above. 
     BRIEF SUMMARY OF THE INVENTION 
     In accordance with one aspect of the present invention, there is provided a removable ink cassette for a printing press, comprising an ink pan and a meter roll, wherein the ink pan and the meter roll are removed from the printing press together by removing the ink cassette from the printing press. 
     In accordance with another aspect of the present invention, there is provided a flexographic printing press, comprising a printing press frame, a first means for mounting an ink pan and a meter roll at the same time to the printing press frame and for removing the ink pan and the meter roll at the same time from the printing press frame, an anilox roll, a plate roll, and an impression roll. 
     In accordance with another aspect of the present invention, there is provided a method of assembling a flexographic printing press, comprising providing a removable ink cassette containing an ink pan and a meter roll, guiding the ink cassette into a predetermined location on the printing press, and removably securing the ink cassette to a printing press frame. 
     In accordance with another aspect of the present invention, there is provided a method of disassembling a flexographic printing press, comprising releasing an ink cassette containing an ink pan and a meter roll from the printing press frame without removing an anilox roll from the printing press frame, and transferring the ink cassette to a first location remote from the printing press. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is schematic illustration of the components of a flexographic printing press. 
     FIG. 2 is a front three dimensional cut away view of an ink cassette of a preferred embodiment of the present invention. 
     FIG. 3 is a rear three dimensional view of the ink cassette of the preferred embodiment of the present invention. 
     FIG. 4 is a front three dimensional view of a flexographic printing press of the preferred embodiment of the present invention. 
     FIG. 5 is a rear three dimensional view of a flexographic printing press of the preferred embodiment of the present invention. 
     FIG. 6 is a side cross sectional view of a section of the flexographic printing press of the preferred embodiment of the present invention where the ink cassette is mounted on the printing press frame. 
     FIG. 7 is a side cross sectional view of a section of the flexographic printing press of the preferred embodiment of the present invention where the ink cassette is removed from the printing press frame. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In view of the problems in the prior art, it is desirable to obtain an ink pan which is removable from the printing press without first removing the anilox roll and/or the meter roll from the printing press. It is also desirable to obtain an ink pan which may be removed from the printing press together with the meter roll for cleaning. 
     The present inventors have discovered that the ink pan may be removed from the printing press without first removing the anilox roll and/or the meter roll by incorporating the ink pan and the meter roll into a removable ink cassette. By removing the ink cassette from the printing press, the press operator simultaneously removes the ink pan and the meter roll from the printing press. The simultaneous, removal of the ink pan and the meter roll reduces the printing press down time by eliminating separate roll and ink pan removal steps. 
     FIG. 1 is a schematic illustration of a flexographic printing press  1  according to one aspect of the present invention. The printing press  1  according to one aspect of the present invention contains a printing press frame  2  (schematically illustrated by dashed lines), at least four rolls (also known as cylinders), and an ink pan or tray  3 . The meter roll  5  (also known as a fountain roll) is located above the ink pan  3  and collects the ink(s) from the ink pan. The meter roll transfers the ink(s) to the anilox roll  7 . The anilox roll  7  in turn transfers the ink(s) to a textured plate roll or cylinder  9 , which contains the image to be printed onto the moving web  11 . The plate roll  9  contacts the first side  13  of the moving web  11  to transfer the image to the first side of the web. An impression roll or cylinder  17  contacts the second side  15  of the moving web  11  to press the web against the plate roll  9 . The ink pan  3  and the meter roll  5  comprise the ink cassette  19  (schematically illustrated by the dashed lines in FIG.  1 ). Thus, by mounting and removing the ink cassette  19  to and from the printing press  1 , the press operator mounts and removes the ink pan  3  and the meter roll  5  on and from the press  1  at the same time. Furthermore, by using the ink cassette  19 , the ink pan  3  can be mounted on and removed from the printing press  3  without first removing the anilox roll  7  and without using special removal tools. 
     FIG. 2 illustrates the elements of a removable ink cassette  19  according to a preferred embodiment of the present invention. The ink cassette  19  contains an ink pan  3  and a meter roll  5  (illustrated in cut away three dimensional view by dashed lines). The meter roll  5  may be mounted over the ink pan  3  and removed from ink pan  3  while the ink cassette  19  is removed from the printing press  1 . The ink cassette may also contain one or more of the following components illustrated in FIG.  2 . However, some or all of the following components may be omitted and/or substituted with other equivalent elements. 
     The ink cassette  19  illustrated in FIG. 2 contains two side plates  21 ,  23  on either side of the ink pan  3 . The side plates  21 ,  23  preferably contain handles  25 ,  27  to allow the press operator to mount and remove the ink cassette  19  to and from the printing press. The handles  25 ,  27  may comprise separate elements from the side plates  21 ,  23 , or each side plate and the respective handle may comprise a unitary body. The side plates and the handles may be made of any suitable material and may have any suitable shape. Preferably, the side plates and the handles are made from aluminum. 
     The ink cassette  19  also contains at least one, and preferably two spacer bars. The spacer bars connect the side plates and the ink pan to each other. For example, as shown in FIG. 2, the lower spacer bar  29  connects the side plates  21 ,  23 . The back spacer bar  31  connects the side plates  21 ,  23  and supports the ink pan  3  from behind. The spacer bar(s)  29 ,  31  may have any suitable shape and may be made of any suitable material, such as aluminum. 
     The ink pan  3  is connected to the back spacer bar  31  by holding pins or screws  33 . However, any other attachment elements may be used to attach the ink pan to the back spacer bar. Furthermore, if desired, the ink pan  3  may be supported by both spacer bars  29 ,  31  or by the lower spacer bar  29 . Alternatively, the ink pan  3  may be supported by the side plates  21 ,  23 . In this case, one or both spacer bars may be omitted, if desired. 
     Preferably, the ink cassette  19  contains at least one locating pin. For example, the locating pin  35  may be mounted on the lower spacer bar  29 . The locating pin  35  fits into a locating opening in the frame of the printing press to assure precise orientation of the ink cassette  19  with the centerline of the printing press  1 . 
     If desired, the ink cassette  19  may also contain at least one side guide bar. As shown in FIG. 2, two side guide bars  37 ,  39  are attached to the side plates  21 ,  23 . However, the side guide bars  37 ,  39  may be instead attached to the lower spacer bar  29 , if desired. The side guide bars  37 ,  39  may have any suitable shape and may be made of any suitable material, such as steel. Alternatively, the side guide bars may be omitted to simplify the ink cassette design. The side guide bars  37 ,  39  may be used in conjunction with the side plates  21 ,  23  as preliminary ink cassette  19  locators during the mounting of the ink cassette on the printing press, to prevent the ink cassette components from striking and damaging the anilox roll  7  of the printing press. 
     The ink cassette may optionally contain a supporting bracket  41  and a supporting knob  43 . The supporting bracket  41  is attached to the back spacer bar  31 , and the supporting knob  43  protrudes from the supporting bracket  41  toward the back of the ink pan  3 . The supporting knob  43  exerts pressure on the back of the ink pan  3 . Thus, the supporting bracket  41  and knob  43  prevent excessive vibration of the ink pan  3  during operation of the printing press by preventing the bottom of the ink pan  3  from swinging backwards during operation. 
     The ink pan  3  also contain an ink drain  45  and an ink drain stopper  47 . By pulling up on the stopper, the press operator can drain the ink from the ink pan  3  out through the ink drain  45  without removing the ink cassette  19  from the printing press. 
     The ink cassette  19  also preferably contains various ink wipers or guards to prevent the ink from spilling sideways from the ink pan  3  during press operation. For example, two ink wipers  49 ,  51  are located on either side of the ink pan  3 . The ink wipers  49 ,  51  contain semicircular openings that fit over the meter roll shaft and over the anilox roll shaft. Furthermore, sponge wipers  53  may be located between the ink wipers and the ink space in the ink pan to further decrease the sideways spilling of the ink during press operation. 
     Blocks  55  with threaded holes may also be added for meter roll adjustments, if desired. All of the above elements may be held together by various fasteners  57 , such as screws bolts, pins or screws and washers. Furthermore, additional pins  59  may be added for limiting the downward movement of meter roll  5 . The ink cassette  19  may also contain meter roll adjustment screws  61 ,  63  which may be turned to adjust the position of the meter roll  5 . Springs  64  may be added to take out backlash in meter roll adjustment screws  61 ,  63 , if desired. Furthermore, the lower spacer bar  29  contains a latch mounting location  65 . The latch will be described in more detail below. 
     The back three dimensional view of the ink cassette  19  is illustrated in FIG.  3 . This figure shows how the above described elements of the ink cassette  19  fit together. Furthermore, the ink cassette  19  may contain a safety switch  67 , which must be actuated by the press operator to enable the operation of the printing press. 
     As described above, the side plates  21 ,  23 , the handles  25 ,  27 , the spacer bars  29 ,  31 , and the side guide bars  37 ,  39  comprise a cassette frame which supports the ink pan  3 . However, the cassette frame and the ink pan may comprise a single, unitary structure or body. For example, the ink cassette and the ink pan may comprise a single injection molded structure made of a suitable material, such as plastic. This structure may contain any or all of the above described side plate, handles, the spacer bar, and side guide bar elements integrally formed as part of the structure. 
     FIG. 4 illustrates a front view of a flexographic printing press  1  according to the preferred embodiment of the present invention, where the ink cassette  19  is mounted to the printing press frame  2 . FIG. 5 illustrates a back view of the flexographic printing press  1  according to the preferred embodiment of the present invention, where the ink cassette  19  is mounted to the printing press frame  2 . The ink pan  3  and the meter roll  5  are mounted to the cassette  19  but not to the frame  2 . As illustrated in FIGS. 4 and 5, the ink cassette  19  is easily accessible to the printing press operator. The operator can remove the ink cassette  19  from the printing press frame  2  by unlatching the cassette  19  and then lifting the cassette  19  out of the frame  2  by the handles  25 ,  27 . Since the ink cassette  19  may be used with any type of printing press, other components of the printing press  1 , such as a control pad, various web feed rollers, etc. will not be described further. Additionally, the removable ink cassette  19  may be used in other types of printing presses other than flexographic printing presses, such as gravure printing presses. 
     FIG. 6 illustrates a side cross sectional view of a section of a flexographic printing press  1  where the ink cassette  19  is mounted on the printing press frame  2 . In FIG. 6, the left side plate  21 , the left handle  25  and the locating pin  35  are illustrated as dashed lines because they are located behind the elements of the cross section, which are illustrated by solid lines. Some elements have been omitted for clarity. 
     The ink pan  3  is mounted to the back spacer bar  31  by a bracket and pins  33 . The supporting bracket  41  and knob  43  prevent the ink pan  3  from swinging backwards, as described above. The lower spacer bar  29  is attached to the side plate  21 , and the locating pin  35  is attached to the lower spacer bar  29 . 
     The meter roll  5  is mounted on a meter roll shaft  69  to the ink cassette  19 . The meter roll  5  is in contact with the anilox roll  7  mounted to the frame  2  by an anilox roll shaft  71 . The ink wipers  49 ,  51  illustrated in FIG. 2 fit around the shafts  69 ,  71 . The meter roll shaft  69  may be mounted to the ink cassette  19  by being threaded through the ink wipers  49 ,  51 . Alternatively, the meter roll shaft  69  may be mounted to the cassette  19  by brackets. The anilox roll shaft  71  is mounted to the press frame  2  by bearing cartridges and latches (not shown). 
     In a preferred aspect of the present invention, the meter roll shaft  69  and the anilox roll shaft  71  are attached to mating gears (not shown) located on the side of the cassette  19 . The gear attached to the anilox roll shaft  71  turns the gear attached to the meter roll shaft  69 , thus turning the meter roll  5  in the ink pan  3 , to provide the ink from the ink pan  3  to the anilox roll  7 . 
     The printing press frame  2  contains a cassette support plate  73  mounted between the outer portions of the frame  2 , as illustrated in FIG.  6 . The support plate  73  may have any desired shape, such as a plate or slab shape, and may be made of any desired material, such as steel. Alternatively, the support plate may have a bar or a cylinder shape. The ink cassette  19  is mounted over the support plate  73  with the side guide bars  37 ,  39  resting on the support plate  73 . The support plate  73  also contains a locating opening  74  into which the locating pin  35  is inserted to orient the ink cassette  19  with the printing press center line. Optionally, eccentric cams  75  may be located above the support plate  73 , such that the cams press down on the side guide bars  37 ,  39  to compensate for a clearance between the side guide bars and the support plate  73 . However, the ink cassette  19  may be mounted to the printing press frame  2  by any other attachment elements, such as by hooks, bolts or friction. 
     Preferably, the ink cassette  19  is also fastened to the printing press frame  2  in addition to being mounted on the support plate  73 . The preferred fastening mechanism is an over-the-center latch  77  illustrated in FIG.  6 . The latch  77  contains a “U” shaped horizontal latch bar  79  which pivots about a pivot axis  81 . The latch bar  79  is connected to a lever  85  at axis  81 . The lever  85  is rotatably or pivotably attached to the support plate  73  of the press frame  2  around a pivot axis  87 . The latch bar  79  is attached to the ink cassette  19  via a latch catch  83 . The latch catch  83  is connected to the lower spacer bar  29  of cassette  19  at location  65  in FIG.  2 . 
     As illustrated in FIG. 6, the latch  77  is in the closed or latched position when the latch bar  79  is placed around the catch  83 . When the latch  77  is in the closed position, the ink cassette  19  is prevented from slipping out from the frame  2  because the latch bar  79  holds the latch catch  83  and the lever  85  together. 
     As illustrated in FIG. 7, to open the latch, the press operator pivots the lever  85  down (clockwise) around axis  87 . This allows the latch bar  79  to pivot down (counterclockwise) around axis  81  and slip off the catch  83 , thus releasing the lever  85  from the latch catch  83 . The ink cassette containing the side plate  21 , the lower spacer bar  29 , the locating pin  35  and the side guide bar  37  is then removed from the press frame  2  containing the support plate  73  and the eccentric cam  75 , as shown in FIG.  7 . The latch bar  79  and the lever  85  are in the open position in FIG. 7 (the back side of the latch bar  79  is shown by dashed lines to illustrate how the latch bar slips on around the catch  83 ). 
     However, various alternative latches and fastening mechanisms may be used instead of the latch  77 . For example, the lever  85  may be attached to the cassette  19  while the latch catch  83  may be attached to the support plate  73  instead. Furthermore, the side plates  21 ,  23  of the cassette  19  may be fastened to the frame  2  in addition to or instead of fastening the lower spacer bar  29  to the support plate  73 . The cassette  19  may also be fastened to the frame  2  and/or the support plate  73  by a threaded screw instead of or in addition to the latch  77 . 
     A method of assembling and disassembling the flexographic printing press  1  according to the preferred embodiment of the present invention will now be described. The printing press  1  is assembled as follows. The press operator provides the removable ink cassette  19  containing the ink pan  3  and the meter roll  5  by bringing the cassette  19  toward the press frame  2 . The operator may hold the cassette  19  by the handles  25 ,  27 , if desired. The operator then guides the ink cassette  19  into a predetermined location on the printing press and removably secures the ink cassette  19  to the printing press frame. 
     The operator may guide the ink cassette  19  into the predetermined location by using the side plates  21 ,  23  and the side guide bars  37 ,  39  as preliminary locators. For example, the side guide bars may slide over the support plate  73  in the frame  2 . Furthermore, if desired, grooves may be provided in the support plate  73  to allow the side guide bars  37 ,  39  to slide in the grooves. After the cassette  19  is preliminarily located over the support plate  73 , the cassette  19  may be oriented with the printing press centerline by pushing the cassette  19  forward to insert the guiding pin  35  attached to the lower spacer bar  29  of the cassette into the guiding opening  74  on the support plate  73 . The operator can then removably secure the cassette  19  to the frame  2  by latching the cassette  19  to the frame  2  by using the latch  77 . The anilox roll  7  does not have to be removed and may remain attached to the frame  2  during the step of mounting the cassette  19  to the frame  2  and removing the cassette  19  from the frame  2 . 
     The press operator disassembles the flexographic printing press  1  by releasing the ink cassette  19  containing the ink pan  3  and the meter roll  5  from the printing press frame  2  without removing an anilox roll  7  from the printing press frame  1 , and transferring the ink cassette to a first location remote from the printing press  1 . The operator releases the cassette  19  by pulling down on the lever  85  to lower the latch bar  79  and to unlatch the ink cassette  19  from the printing press frame  2 . 
     After removing the cassette  19  from the printing press, the operator can transfer the cassette  19  to a cleaning station, where the meter roll  5  is removed from the cassette  19  and the ink pan  3  and the meter roll  5  are cleaned. While the cassette is removed, the anilox roll  7  may be cleaned while it is still mounted on the press  1 . The cassette  19  is then remounted to the press  1  after the step of cleaning the ink pan  3 . Alternatively, in order to further decrease press down time, a second ink cassette containing a filled ink pan and a meter roll may be mounted on the press for the next press run while the first ink cassette is being cleaned. Thus, the ink cassette  19  of the preferred embodiment of the present invention decreases press set up time and eases the clean up of the ink pan  3  by allowing the mounting and removal of the ink pan  3  together with the meter roll  5  without removing the anilox roll  7 . 
     The preferred embodiments have been set forth herein for the purpose of illustration. However, this description should not be deemed to be a limitation on the scope of the invention. Accordingly, various modifications, adaptations, and alternatives may occur to one skilled in the art without departing from the spirit and scope of the claimed inventive concept.