INK METERING APPARATUS WITH OBTUSE METERING MEMBER

摘要

Ink metering apparatus comprising a resilient surfaced roller urged into pressure indented relation with a lithographic printing plate; a source of ink to apply an excess of ink to the depleted surface of the roller which has applied ink to the printing plate; and a resilient metering member having two hard, flexible edges formed on opposite sides of a support surface, resiliently urged radially of the roller and rigidly supported in a direction tangent to the roller surface for forming a film on the roller surface. Ink carried by the resilient roller surface impinges against a metering surface on the metering member adjacent the first polished edge. The angle formed between the metering surface and the resilient roller surface at the first polished edge, and the pressure on the ink at this edge are adjusted, such that, a given angle and pressure relationship for a given viscosity of ink produces a given printing ink film. The second polished edge is positioned such that the angle of departure between the metering member and the surface of the roller is sufficient to cause separation of the ink from the metering member to prevent a buildup of ink along the surface of the metering member. Pressure at the first polished edge is significantly greater than pressure at the second polished edge.