Abstract:
An ink fountain device for a rotary printing press includes a rotatably supported ink fountain roller, ink fountain, at least one intermediate ink dam, a press unit, and an adjustment bolt. The ink fountain is comprised of an ink fountain blade and a pair of ink dams. The intermediate ink dam includes a press plate, an adjustable plate, and an operation plate. The press unit presses the press plate through the operation plate and adjustment plate toward the outer surface of the ink fountain roller and toward the ink fountain blade. The adjustment bolt adjusts a tight contact state of the press plate with respect to at least one of the outer surface of the ink fountain roller and the fountain blade.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an ink fountain apparatus for a rotary printing press, which stores ink to be supplied to a plate surface and, more particularly, to the structure of intermediate ink dams arranged between a pair of opposing ink dams. 
     When printing is to be performed with a rotary printing press, the plate sometimes has a pattern at only its portion in the entire width depending on the specifications of the printing products to be obtained. In this case, if ink is stored in the entire ink fountain and printing is performed, the ink may be wasted. Hence, intermediate ink dams are formed on two sides of a portion corresponding to the pattern, and the ink is stored in only inside the intermediate ink dams. In rainbow printing wherein inks of different colors are supplied to appropriate portions in the entire length of the plate cylinder and several colors are printed at once, intermediate ink dams are provided so adjacent inks do not mix with each other. Japanese Utility Model Publication No. 6-46675 (reference 1) discloses an ink fountain apparatus of this type. 
     The ink fountain apparatus shown in reference 1 has an intermediate ink dam unit, movable in the axial direction, on a holder shaft extending parallel to an ink fountain roller. The intermediate ink dam unit has a holder fitted on the holder shaft, a support plate pivotally supported by the holder through a link, an intermediate ink dam fixed to the support plate and made of an elastic material, a spring for pressing the edge of the intermediate ink dam to abut against a blade, and a pivoting force application member for applying a pivoting force to the holder in a direction to press the intermediate ink dam to abut against the outer surface of the fountain roller. 
     In this arrangement, because of cooperation with the elastic force of the spring member, the acting force of the pivoting force application member, and the link motion, the elastic edge of the intermediate ink dam is pressed by the outer surface of the ink fountain roller and the flat surface of the blade to abut against them, and comes into tight contact with them. 
     In the conventional ink fountain apparatus described above, the intermediate ink dam is brought into tight contact with the outer surface of the ink fountain roller and the blade by pivoting the whole intermediate ink dam with the pivoting force application member. In this pivot motion, although the whole intermediate ink dam can be brought into tight contact with the outer surface of the ink fountain roller and the blade, it cannot necessarily be brought into uniform contact with them due to a working tolerance, non-uniform wear, or the like. Therefore, in the conventional ink fountain apparatus, the tight contact force cannot be partially adjusted. 
     Accordingly, when the tight contact force of the intermediate ink dam decreases partially, the ink flows out through this portion, so the amount of ink consumed may increase, and the printing quality degrades in rainbow printing or the like. When the intermediate ink dam is to be removed, the link mechanism and the like must be removed, resulting in a cumbersome operation. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an ink fountain apparatus for a rotary printing press, in which the consumption of ink is reduced by preventing outflow of the ink. 
     It is another object of the present invention to provide an ink fountain apparatus for a rotary printing press, in which the printing quality in rainbow printing is improved. 
     It is still another object of the present invention to provide an ink fountain apparatus for a rotary printing press, in which an intermediate ink dam can be removed easily. 
     In order to achieve the above objects, according to the present invention, there is provided an ink fountain apparatus for a rotary printing press, comprising a rotatably supported ink fountain roller, an ink fountain comprised of a bottom plate with one end supported close to the ink fountain roller and a pair of ink dams standing upright from the bottom plate to correspond to two ends of the ink fountain roller and arranged to oppose in an axial direction of the ink fountain roller, at least one intermediate ink dam standing upright between the ink dams from the bottom plate, the intermediate ink dam including a first member in contact opposite to an outer surface of the ink fountain roller and the bottom plate, a second member in contact opposite to the first member, and a third member in contact opposite to the second member, press means for pressing the first member through the third and second members toward the outer surface of the ink fountain roller and toward the bottom plate, and an adjustment tool for adjusting a tight contact state of the first member with respect to at least one of the outer surface of the ink fountain roller and the bottom plate. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plan view of the main part of an ink fountain apparatus for a rotary printing press according to an embodiment of the present invention; 
     FIG. 2 is a sectional view taken along the line II—II of FIG. 1; 
     FIG. 3 is an exploded perspective view of the main part of the ink fountain apparatus shown in FIG. 1; and 
     FIG. 4 is a perspective view of the holder of the ink fountain apparatus shown in FIG.  1 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention will be described in detail with reference to the accompanying drawings. 
     FIG. 2 shows an ink fountain apparatus for a rotary printing press according to an embodiment of the present invention. Referring to FIG. 2, an ink fountain roller  1  rotatable in the direction of an arrow A axially extends between a pair of frames (not shown) arranged to oppose each other through a predetermined distance, and a blade base  2  is provided beside the ink fountain roller  1  such that its two ends are supported by the pair of frames. A large number of ink fountain keys  3  divided in the axial direction of the ink fountain roller  1  are placed on a slant surface at the upper end of the blade base  2 . When a motor (not shown) is driven, the aperture ratios of the distal ends of the ink fountain keys  3  are adjusted in directions to become close to and away from the outer surface of the ink fountain roller  1 . 
     One ink fountain blade  4  formed of a thin steel plate to serve as a bottom plate is magnetically attracted so it comes into tight contact with the ink fountain key  3  to cover the large number of ink fountain keys  3 . Referring to FIG. 1, a pair of opposing ink dams  5  arranged to correspond to the two ends of the ink fountain roller  1  are fixed to a member (not shown) swingably supported between the frames, such that the inner surfaces of their distal ends are pressed by the two end faces of the ink fountain roller  1 . The pair of ink dams  5  standing upright from the ink fountain blade  4 , the outer surface of the ink fountain roller  1 , and the ink fountain blade  4  make up a tub-like ink fountain  6 . A bar  8  extending in the axial direction of the ink fountain roller  1  behind the ink fountain  6  has two ends fixed to the member (not shown) swingably supported between the frames. 
     As shown in FIG. 4, a thin-plate-like rectangular parallelepiped holder  10  has a fitting groove  11  with a U-shaped section to communicate with its upper end and its side surface on the ink fountain roller  1  side, and a notch  12 , extending in the axial direction of the ink fountain roller  1 , in its lower end. The notch  12  is slightly larger than the sectional area of the bar  8 . As shown in FIG. 2, a blind hole-like spring accommodating hole  13  is formed in the upper portion of the holder  10 . A threaded portion  13   a  is formed at the inlet port of the spring accommodating hole  13 , and a small-diameter insertion hole  13   b  is formed in the spring accommodating hole  13  to reach its bottom. A screw hole  14  with a screw portion extending to reach a recess  8   a  of the bar  8  is formed in the lower portion of the holder  10 . 
     Referring to FIG. 2, an operation rod  15  serving as a thin, elongated press member has a spring accepting portion  15   a,  with a diameter slightly smaller than the diameter of the spring accommodating hole  13 , at its distal end. A press shaft portion  15   b  with a diameter slightly smaller than the diameter of the insertion hole  13   b  projects from one end of the spring accepting portion  15   a  toward the ink fountain roller  1 . A handle member  16  is fixed to the proximal end (counter distal end) of the operation rod  15 . A screw  17  has a screw portion  17   a  threadably engageable with the threaded portion  13   a  of the spring accommodating hole  13 , and an insertion hole  17   b  with a diameter slightly larger than the diameter of the operation rod  15  is formed at the center of the screw  17 . 
     A compression coil spring  18  serving as a biasing means is elastically mounted between the spring accepting portion  15   a  of the operation rod  15  inserted in the spring accommodating hole  13  and the screw  17  with the screw portion  17   a  threadably engaging with the threaded portion  13   a.  The press shaft portion  15   b  of the operation rod  15  in the insertion hole  13   b  is then biased from the holder  10  in a direction to become close to the ink fountain roller  1 . A set screw  19  threadably engages with the screw hole  14  of the holder  10  and serves to fix the holder  10  to the bar  8 . A nut  20  threadably engages with the set screw  19  and serves to regulate forward/backward movement of the set screw  19 . 
     Referring to FIG. 1, a pair of opposing intermediate ink dams  25  are arranged between the ink dams  5 . As shown in FIG. 3, each intermediate ink dam  25  is comprised of an operation plate (third member)  26 , a pair of sandwiching plates  27  and  28  for sandwiching the operation plate  26  from two sides, an adjustment plate (second member)  29  in contact opposite to the lower surface of the operation plate  26 , and a press plate (first member)  30  having an upper end face in contact opposite to the lower surface of the adjustment plate  29 . The press plate  30  is arranged in the same planar direction as those of the operation plate  26  and sandwiching plates  27  and  28 . 
     The operation plate  26  is formed of a horizontal portion  26   a  extending in a direction perpendicular to the axial direction of the ink fountain roller  1  and an upright portion  26   b  extending obliquely upward from the distal end of the horizontal portion  26   a,  to have a substantial L shape. A substantially L-shaped support  31  is integrally formed at the front end of the horizontal portion  26   a  to be thicker than the horizontal portion  26   a  because of steps  31   a.  The horizontal portion of the support  31  is fitted in the fitting groove  11  of the holder  10 , and part of the vertical portion of the support  31  forms an engaging surface  31   b  formed of a slant surface. As shown in FIG. 2, the slanting direction of the engaging surface  31   b  is set such that an angle α formed by the upper surface of the ink fountain blade  4  and the extension of the slant surface of the engaging surface  31   b  is an acute angle. 
     As shown in FIG. 3, the operation plate  26  has, in its the horizontal portion  26   a  and upright portion  26   b,  a total of five insertion holes  32  and a total of five screw holes  33 . Three adjustment bolts  34   a,    34   b,  and  34   c  threadably engage with screw holes formed at the upper and lower portions of the upright portion  26   b  and the substantial center of the horizontal portion  26   a  of the operation plate  26 . The adjustment bolt  34   b  attached to the lower portion of the upright portion  26   b  moves forward/backward (in the direction indicated by an arrow D) toward a point B where the outer surface of the ink fountain roller  1  and the ink fountain key  3  oppose each other. The sandwiching plate  27  has five screw holes  36  corresponding to the insertion holes  32  of the operation plate  26 . The sandwiching plate  28  has five insertion holes  37  with spot-faced upper surfaces to correspond to the insertion holes  32  of the operation plate  26 , and five insertion holes  38  corresponding to the screw holes  33 . 
     The adjustment plate  29  is formed by bending a thin steel plate with spring properties into a substantial L shape. The adjustment plate  29  is comprised of a horizontal portion  29   a  in contact opposite to the lower surface of the horizontal portion  26   a  of the operation plate  26 , and an upright portion  29   b  in contact opposite to the rear end face of the upright portion  26   b.  The press plate  30  standing upright in contact with the lower surface of the adjustment plate  29  is made of polyvinyl chloride as an elastic material with an overall wear resistance into a substantial L shape. The press plate  30  is comprised of a horizontal portion  39  with an upper end face in contact opposite to the horizontal portion  29   a  of the adjustment plate  29 , and an upright portion  40  with a front end face in contact opposite to the upright portion  29   b  of the adjustment plate  29 . 
     The lower end face of the horizontal portion  39  of the press plate  30  serves as a linear blade press portion  39   a  for pressing the blade  4 , and the rear end face of the upright portion  40  serves as an arcuate ink fountain press portion  40   a  for pressing the outer surface of the ink fountain roller  1 . The width of the adjustment plate  29  and the plate thickness of the press plate  30  are almost the same, and are slightly smaller than the thicknesses of the horizontal portion  26   a  and upright portion  26   b  of the operation plate  26 . 
     How to build the intermediate ink dam  25  in the ink fountain  6  will be described. 
     As shown in FIG. 3, flat head screws (not shown) inserted from the insertion holes  37  of the sandwiching plate  28  extend through the insertion holes  32  of the operation plate  26 , to threadably engage with the screw holes  36  of the sandwiching plate  27 . This fixes the sandwiching plate  28  to the sandwiching plate  27  to sandwich the operation plate  26 . Then, set screws (not shown) are inserted from the insertion holes  38  of the sandwiching plate  28  to threadably engage with the screw holes  33  of the operation plate  26 . This fixes the operation plate  26  to the sandwiching plate  28 , so the operation plate  26  is sandwiched between the sandwiching plates  27  and  28 . 
     When the operation plate  26  is sandwiched by the sandwiching plates  27  and  28 , a space between the sandwiching plates  27  and  28  is formed under the operation plate  26 . The adjustment plate  29  and press plate  30  are sequentially engaged in this space, so the adjustment plate  29  is in contact opposite to the lower surface of the operation plate  26  and the press plate  30  is in contact opposite to the lower surface of the adjustment plate  29 . When the support  31  of the intermediate ink dam  25  built in this manner is fitted in the fitting groove  11  of the holder  10 , as shown in FIG. 2, the intermediate ink dam  25  is supported in the fitting groove  11  to be slidable in a direction indicated by arrows E-F perpendicular to the axial direction of the ink fountain roller  1 . 
     At this time, the blade press portion  39   a  and ink fountain press portion  40   a  of the press plate  30  project from the lower and rear ends, respectively, of each of the sandwiching plates  27  and  28 . The elastic force of the compression coil spring  18  biases the operation rod  15  in a direction indicated by the arrow E to become close to the ink fountain roller  1 , and the distal end of the press shaft portion  15   b  projecting from the insertion hole  13   b  abuts against the engaging surface  31   b  of the support  31 . Since the engaging surface  31   b  is formed in such a direction that the angle α formed by the ink fountain blade  4  and the extension of the slant surface  31   b  is an acute angle, the press direction with respect to the press plate  30  changes as indicated by an arrow C. More specifically, the press plate  30  is pressed almost toward the point B where the outer surface of the ink fountain roller  1  and the ink fountain key  3  oppose each other. Therefore, the blade press portion  39   a  and ink fountain press portion  40   a  of the press plate  30  respectively press the ink fountain blade  4  and the outer surface of the ink fountain roller  1 , and accordingly the blade press portion  39   a  and ink fountain press portion  40   a  come into tight contact with the ink fountain blade  4  and the outer surface of the ink fountain roller  1 , respectively. 
     In this embodiment, since the operation plate  26  presses the press plate  30  through the thin plate-like adjustment plate  29 , the press plate  30  is pressed uniformly and will not be locally fractured. Since the adjustment plate  29  is made of an elastic material, local elastic deformation of the press plate  30  can be prevented, so the tight contact force becomes uniform throughout the press plate  30 . 
     How to adjust the tight contact state of the press plate  30  with respect to the ink fountain blade  4  and the outer surface of the ink fountain roller  1  will be described. 
     When the tight contact state of the whole press plate  30  is to be adjusted, the screw  17  is pivoted to change the forward/backward moving amount of the screw  17  with respect to the spring accommodating hole  13 , thereby changing the elastic force of the compression coil spring  18 . Thus, the press force of the compression coil spring  18  to press the press shaft portion  15   b  toward the engaging surface  31   b  changes, so the whole tight contact can be adjusted. This adjusting operation can be performed by only pivoting the screw  17 . Therefore, tight contact adjustment can be performed easily. 
     If tight contact between the blade press portion  39   a  and ink fountain blade  4  and that between the ink fountain press portion  40   a  and the outer surface of the ink fountain roller  1  are partly insufficient, the threadable engagement amounts of the adjustment bolts  34   a,    34   b,  and  34   c  are adjusted separately, to adjust the tight contact partly. In this case, when the threadable engagement amount of the adjustment bolt  34   b,  which moves forward/backward with respect to the point B where the outer surface of the ink fountain roller  1  and the ink fountain keys  3  oppose each other, is adjusted, the tight contact between the blade press portion  39   a  and ink fountain blade  4  and that between the ink fountain press portion  40   a  and the outer surface of the ink fountain roller  1  can be adjusted simultaneously. 
     According to this embodiment, the tight contact state of the press plate  30  can be partly adjusted, so partial outflow of the ink can be prevented. As a result, the amount of ink consumed can be reduced, and the printing quality of rainbow printing can be improved. As the press plate  30  is made of the elastic material, when the press state is to be partly adjusted, partial deformation of the press plate  30  due to the adjustment bolts  34   a  to  34   c  can be prevented. 
     As shown in FIG. 3, a projection  39   b  for pressing the upper surface of the distal end of the corresponding ink fountain key  3  is formed at the distal end of the blade press portion  39   a  of the press plate  30 . Since the projection  39   b  locally presses the upper surface of the distal end of the ink fountain key  3 , the tight contact of the press plate  30  is further improved, and the ink from the ink fountain roller  1  is prevented from entering a portion between the blade press portion  39   a  and ink fountain blade  4 , through the blade press portion  39   a  and the ink fountain key  3 . As a result, ink to be used for subsequent printing is prevented from mixing with printing ink used previously. Also, the ink fountain key  3  is prevented from causing an operation error because the entering ink solidifies. 
     Since the press plate  30  is made of the wear-resistant elastic material, wear of the press plate  30  at its portion in contact opposite to the ink fountain roller  1  and that in contact opposite to the ink fountain blade  4  are reduced. Also, the tight contact of the press plate  30  at its portion in contact opposite to the ink fountain roller  1  and that in contact opposite to the ink fountain blade  4  are improved. 
     To remove the intermediate ink dam  25 , as shown in FIG. 2, the operator holds the holding member  16 , and moves the operation rod  15  against the elastic force of the compression coil spring  18  in a direction to separate it away from the ink fountain roller  1 . Then, the operator releases the engaging surface  31   b  which has been pressed by the press shaft portion  15   b,  and removes the operation rod  15  from the holder  10 . In this manner, the intermediate ink dam  25  can be mounted and detached by merely moving the operation rod  15  against the elastic force of the compression coil spring  18  without requiring a tool. Thus, the intermediate ink dams  25  can be mounted and detached easily. 
     When the intermediate ink dam  25  is to be positionally adjusted in the axial direction of the ink fountain roller  1 , in FIG. 2, the operator loosens the fastened nut  20  and rotates the set screw  19  to move it backward. Then, as shown in FIG. 4, the operator releases the holder  10  which has been fixed to the bar  8 , and moves the holder  10  in the axial direction of the ink fountain roller  1  indicated by arrows G-H. In this manner, position adjustment of the intermediate ink dam  25  can be performed by merely loosening the fastened nut  20  and thereafter rotating the set screw  19 . As a result, operation becomes easy. 
     In the above embodiment, the press plate  30  is made of polyvinyl chloride. However, the present invention is not limited to this, but the press plate  30  can be made of any elastic material as far as it has wear resistance. 
     As has been described above, according to the present invention, the tight contact state between the intermediate ink dam and blade and that between the intermediate ink dam and the outer surface of the ink fountain roller are partially adjusted, so the tight contact force is improved and partial outflow of the ink can be prevented. Therefore, the amount of ink consumed is reduced, and the printing quality of rainbow printing is improved.