Ink dam for printing press

In a printing press:

• a pair of rolls in contact with each other to enable ink transfer therebetween;
• a circumferential groove in one of said rolls dividing said one roll into two sections;
• a divider having openings therein for accommodating said rolls, said divider having first and second edges along said openings, one of said edges extending into said groove in said one roll entirely therearound, the other of said edges adjacent the other of said rolls, said other edge having a groove therein, said divider comprising at least two sections cooperating to define the opening having said one of said edges;
• said divider having air holes therein terminating at said first and second edges for accommodating the flow of compressed gas therethrough into said circumferential groove and against said other roll to prevent transfer of ink between said two sections of said one roll and across the surface of said other roll.

In a printing press:

• a first roll;
• a second roll in contact with said first roll whereby ink is transferred between said rolls;
• a circumferential groove in said first roll dividing said first roll into two sections;
• a divider comprising at least two separable sections cooperating to define a first opening therein for accommodating said first roll, said divider comprising a first edge along said first opening which extends into said groove entirely therearound;
• said divider having first air holes along said first edge for accommodating the flow of compressed gas therethrough into said groove in said fountain roll to prevent the transfer of ink between said two sections of said first roll;
• said divider having a second opening therein for accommodating said second roll, said divider comprising a second edge along said second opening adjacent said second roll, said second edge having a groove therein and having second air holes along said second edge groove for accomodating the flow of compressed gas therethrough against said second roll to prevent the transfer of ink along said second roll past said divider.

In a printing press:

• a fountain roll having at least one circumferential groove therein for dividing said roll into sections;
• an ink fountain associated with said fountain roll and having means for applying different colored inks to different sections of said fountain roll;
• an anilox roll to which ink is transferred from said fountain roll;
• a plurality of dividers for dividing the ink fountain into separate ink compartments, and for cooperation with said fountain roll and said anilox roll to prevent ink transfer between adjacent sections on each roll, each divider having a hole through which the fountain roll extends, each divider having a circumferential edge around said hole which extends into a groove on said fountain roll, each divider having another edge which rides against said anilox roll, said another edge being provided with a groove therein, a plurality of air ports disposed along said circumferential edge and said other edge and along said groove in said other edge;
• means for supplying compressed air for expulsion through said holes;
• a resilient hollow pneumatically operated sealing tube disposed between the bottom of each divider and said ink fountain to provide a mechanical seal therebetween and to bias said divider against said anilox roll;
• and means for supplying compressed air to said sealing tube.