Patent Publication Number: US-2005115423-A1

Title: Dampening water feeding apparatus

Description:
FIELD OF THE INVENTION  
      The invention relates to an apparatus for feeding dampening water in an offset printing press.  
     PRIOR ART  
      An apparatus has been commercially available for feeding dampening water in an offset printing press, as disclosed in Japanese Patent No. 2,746,975. The apparatus is a spray-type including a plurality of spray nozzles arranged in a row in a direction. Each of the nozzles includes an outlet formed therein for spraying the dampening water. The outlet comprises a slit having a cross section elongated in the direction in which the nozzles are arranged in the row, to spray the dampening water in an increasing fan-shaped area defined in the direction in which the nozzles are arranged in the row.  
      The apparatus involves ink mist generated by the printing press and drifted around the apparatus. Lint is also generated by the printing press and drifted around the apparatus. In addition, air stream is generated under the influence of dampening water especially on the opposite sides of each of the nozzles in the direction in which the nozzles are arranged in the row, to be directed toward the nozzle when spraying the dampening water. The air stream is strengthened under the influence of dampening water for a moment to be directed toward the nozzle when stopping the dampening water.  
      Accordingly, the ink and lint are entrained on the air stream and directed toward the nozzle to be adhered to and deposited on the nozzle. It is therefore required to frequently clean the nozzle of ink and lint. The outlet may be clogged with ink and lint. In this case, the apparatus cannot conveniently spray the dampening water in the fan-shaped area, resulting in defect or poor quality of printed product.  
      It is therefore an object of the invention to provide a new and improved apparatus for feeding dampening water in an offset printing press, to overcome the above problems. The apparatus comprises a plurality of spray nozzles arranged in a row in a direction. Each of the nozzles includes an outlet formed therein for spraying the dampening water. The outlet has a cross section elongated in the direction in which the nozzles are arranged in the row, to spray the dampening water in an increasing fan-shaped area defined in the direction in which the nozzles are arranged in the row.  
      Other object is to provide the apparatus in which it is not required to frequently clean the nozzle of ink and lint.  
      Other object is to provide the apparatus which can keep the outlet from being clogged with ink and lint to conveniently spray the dampening water in the fan-shaped area, without resulting in defect or poor quality of printed product.  
     SUMMARY OF THE INVENTION  
      According to the invention, the apparatus further comprises baffle means disposed at least on the opposite sides of each of the nozzles in the direction in which the nozzles are arranged in the row, to baffle air stream from being directed toward the nozzle when spraying and stopping the dampening water.  
      In a preferred embodiment, the nozzles are arranged longitudinally of a dampening roller to spray the dampening water onto the dampening roller.  
      Each of the nozzles includes a groove formed therein. The groove has a bottom and extends in the direction in which the nozzles are arranged in the row. The outlet is formed in the bottom centrally thereof in the direction in which the nozzles are arranged in the row. The baffle means is higher than the nozzle to baffle the air stream from being directed toward the groove and the outlet.  
      The baffle means comprises a baffle wall which is annular to be disposed around each of the nozzles.  
      A nut is disposed around each of the nozzles so that the nozzle can be fixed to a solenoid valve by the nut. The baffle wall is formed integrally with the nut.  
      The baffle means may extend toward the fan-shaped area and terminate at a position near the fan-shaped area.  
      The baffle moans may extend toward the fan-shaped area and terminate at a position tangent to the fan-shaped area. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a schematically perspective view of a preferred embodiment of the invention.  
       FIG. 2  is a sectional view of the apparatus of  FIG. 1 .  
       FIG. 3  is a plan view of the nozzle of  FIG. 2 .  
       FIG. 4  is a sectional view of the nozzle of  FIG. 2 .  
       FIG. 5  is an explanatory view of the dampening roller of  FIG. 1  having dampening water receiving portions.  
       FIG. 6  is a sectional view of other embodiment.  
       FIG. 7  is a sectional view of other embodiment.  
       FIG. 8  is a sectional view of other embodiment.  
       FIG. 9  is a sectional view of other embodiment.  
       FIG. 10  is a sectional view of other embodiment.  
       FIG. 11  is a plan view of other embodiment. 
    
    
     DETAINED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Turning now to the drawings,  FIG. 1  illustrates an apparatus for feeding dampening water in an offset printing press, according to the invention. The apparatus is a spray-type including a plurality of nozzles  2  arranged in a row in a direction X. The apparatus further includes a plurality of solenoid valves  4  received in and protruding from a spray bar  6 , as shown in  FIG. 2 . A nut  8  is disposed around each of the nozzles  2  and threadedly engaged with the solenoid valve  4  so that the nozzle  2  can be fixed to the solenoid valve  4  by the nut  8 . A pipe  10  is received in the spray bar  6  and connected to tho solenoid valve  1  so that dampening water can be directed to the solenoid valve  4  through the pipe  10 . The dampening water is supplied to the nozzle  2  through the solenoid valve  4 .  
      Each of the nozzles  2  includes an outlet  12  formed therein for spraying the dampening water, as shown in  FIG. 3 . The outlet  12  comprises a slit having a cross section elongated in the direction X in which tho nozzles  2  are arranged in the row, to spray the dampening water in an increasing fan-shaped area  14  defined in the direction X in which the nozzles  2  are arranged in the row. The fan-shaped area  14  has an angle θ  1 .  
      The nozzles  2  are arranged longitudinally of a dampening roller  16  to spray the dampening water onto the dampening roller  16 . The dampening roller  16  comprises a fountain roller disposed in contact with a ducter roller  18  which lo disposed in contact with a plate cylinder  20  so that the fountain roller  16  can cooperate with the ducter roller  18  to feed the dampening water to the plate cylinder  20 .  
      It should be recognized that the apparatus involves ink mist generated by the printing press and drifted around the apparatus. Lint is also generated by the printing press and drifted around the apparatus. In addition, air stream  22  is generated under the influence of dampening water especially on the opposite sides at each of the nozzles  2  in the direction X in which the nozzles  2  are arranged in the row, to be directed toward the nozzle  2  when spraying the dampening water. The air stream  22  is strengthened under the influence of dampening water for a moment to be directed toward the nozzle  2  when stopping the dampening water.  
      Under the circumstances, the apparatus further includes baffle means  24  disposed at least on the opposite sides of each of the nozzles  2  in the direction X in which the nozzles  2  are arranged in the row, to baffle air stream  22  from being directed toward the nozzle  2  when spraying and stopping the dampening water.  
      Accordingly, the ink and lint are merely entrained on the air stream  22  not to be directed toward the nozzle  2 . The apparatus can therefore prevent the ink and lint from being adhered to and deposited on the nozzle  2 . As a result, it is not required to frequently clean the nozzle  2  of ink and lint. The apparatus can also keep the outlet  12  from being clogged with ink and lint, to conveniently spray the dampening water in the fan-shaped area  14 , without resulting in defect or poor quality of printed product.  
      In the embodiment, each of nozzles  2  includes a groove  26  formed therein, as shown in  FIG. 4 . The groove  26  has a bottom  28  and extends in the direction X in which the nozzles  2  are arranged in the row. The outlet  12  is formed in the bottom  28  centrally thereof in the direction X in which the nozzles  2  are arranged in the row. The baffle means  24  is higher than the nozzle  2  to baffle the air stream  22  from being directed toward the groove  26  and the outlet  12 .  
      The apparatus can therefore prevent the ink and lint from being adhered to and deposited on the bottom  28 . The arrangement can also keep the outlet  12  from being clogged with ink and lint.  
      In addition, the baffle moons  24  comprises a baffle wall which  16  annular to be disposed around each of the nozzles  2 . The baffle wall  24  is formed integrally with the nut  8 .  
      Accordingly, the baffle wall  24  can be incorporated into the apparatus without difficulty when the nozzle  2  is fixed to the solenoid valve  4  by the nut  8 . The baffle wall  24  can baffle the air stream  22  from being directed toward the nozzle  2  even if the air stream  22  is generated not only on the opposite sides of each of the nozzles  2  but also around of each of the nozzles  2 .  
      Furthermore, the baffle wall  24  extends toward the fan-shaped area  14  and terminates at a position near the fan-shaped area  14 . The baffle wall  24  can therefore intercept the air stream  22  effectively. The air stream  22  cannot be directed toward the nozzle  2  at all.  
      It should be recognized that the dampening roller  16  has dampening water receiving portions  30  onto each of which the outlet  12  sprays the dampening water, as shown in  FIG. 5 . The nozzles  2  are arranged longitudinally of the dampening roller  16 , as described above. The outlet  12  has the cross section elongated and sprays the dampening water in the fan-shaped area  14 , as also described above. The receiving portions  30  are formed around the positions  12 ′ of outlets  12  imaginatively projected in  FIG. 5 , to be arranged and elongated longitudinally of the dampening roller  16 . In addition, overlapping portions  32  are formed between the receiving portions  30  not to be short of dampening water between the receiving portions  30 .  
      In this connection, the battle wall  24  may extend toward the fan-shaped area  14  and terminate at a position tangent to the fan-shaped area  14 , as shown in  FIG. 6 . In this case, it has been confirmed by test that the baffle wall  24  makes the dampening water refracted outwardly of the fan-shaped area  14  so that the fan-shaped area  14  can be enlarged into an enlarged area having an angle θ  2 . Accordingly, the overlapping portions  32  are enlarged by means of the enlarged areas  14 . The arrangement can therefore spray the dampening water uniformly throughout the length of the dampening roller  16  to improve the quality of printed product.  
      The baffle wall  24  may be fixed to the nut  8  by screws or the like, as shown in  FIG. 7 . The baffle wall  24  may be annular to have a cross section of circle or not circle. The baffle wall  24  may be continuous. The baffle wall  24  may include slits formed therein to be not continuous.  
      The baffle wall  24  may include an end portion  34  inclined outwardly at an angle corresponding to the angle θ  1  of the fan-shaped area  14 , as shown in  FIG. 8 .  
      The baffle wall  24  may include an end portion  36  bent outwardly, as shown in  FIG. 9 .  
      The baffle wall  24  may include an end portion  38  bent inwardly, as shown in  FIG. 10 .  
      A pair of baffle walls  40  may be disposed on the opposite sides of each of the nozzles  2  in the direction in which the nozzles  2  are arranged in the row, as shown in  FIG. 11 .