Abstract: Ink cups of pad printing machines are produced by insert molding a flanged plastic cup body directly on a hard doctor knife blade ring of carbide whereby the mounting portion of the blade ring is embedded and mold-bonded with the cup flange. The resulting cup is included in a pad printing machine that includes an annular hold-down ring that engages directly and uniformly on the cup flange.

Abstract: The doctor portion of the ink cup of a pad printing machine is formed of a polymeric composite which has high compressive strength and high resistance to chemicals, notably to printing inks. The polymeric doctoring portion is tapered and defines a narrow distal end surface which circumscribes the open end of the cup for doctoring engagement with an opposed plastic gravure surface. The doctoring portion may be a separate ring element suitably mounted at the open end of the cup body or it may be a unitary part of the cup. In a preferred embodiment, this doctoring portion is a ring formed of a polymer composite reinforced by carbon fibers and which is permeated by lubricant particles or granules of graphite.

Abstract: A pad printing machine is disclosed in which the downward pressure forces are transferred to a thrust collar on the ink cup by application through a divided bearing which applies the hold-down forces at points that are spaced forward and rearward of the transverse pivot axis of the ink cup, and only at such spaced points, to resist rocking moments such as may arise from the reciprocating movements of the cliche. Further, the thrust collar is a combination of a very rigid pressure ring and a hard but slightly resilient plastic pressure distribution ring which is accurately machined after subassembly with the rigid ring to assure full mating engagement with the upper surface of the annular flange around the entire circumference of the ink cup, to assure uniform pressure of the entire knife edge on the cliche. In a preferred embodiment, the ink cup also is formed of a hard plastic.