Ink fountain dividing key

Claim 1

An ink fountain dividing key for use in adjustably separating the surface of an ink fountain roller of uniform radius rotatable in an ink fountain of a rotary printing machine into a plurality of longitudinally spaced, separate ink applying surfaces, said ink fountain dividing key comprising: a body having a curved front face, said curved front face having a radius of curvature the same as the uniform radius of the ink fountain roller disposed in the ink fountain, said curved front face being positioned closely adjacent and spaced from the surface of the ink fountain roller and being shiftable along the longitudinal length of the ink fountain roller; a groove generally in the middle of said front face, said groove extending along said curved front face generally perpendicular to the longitudinal surface of the ink fountain roller and being closed at upper and lower ends of said curved front face; a plurality of bore holes extending through said body of said ink fountain dividing key and terminating in said groove; means for supplying compressed air to said groove through said bore holes, no part of said dividing key contacting said roller at any location said compressed air being the sole means contacting said roller to separate the surface of the ink fountain roller into separate ink applying surfaces; and means for shifting said ink fountain dividing key longitudinally along the length of the ink fountain roller.