| 摘要 |
<p>A printing plate is mounted on a driven print cylinder, and ink is applied to the face of the plate by an ink applying roll which forms a nip with an ink distributing roll positioned below and horizontally offset from the ink applying roll. The rolls are driven in timed relation by a set of connecting gears and are adjustable as a unit independently on opposite ends for selecting precision uniform contact of the ink applying roll with the printing plate. In addition, the ink distributing roll is adjustable on opposite ends independently relative to the ink applying roll for precisely adjusting the nip between the rolls without changing the drive relationship. The ink is supplied to the rolls by an ink recirculating pump actuated by a cam driven by the same motor which drives the print cylinder, the ink rolls and an optional web cut-off unit. The ink recirculating pump includes a reciprocating plunger-type ink supply tube disposed concentrically within an ink return tube, and the concentric tubes depend from a manifold and cap assembly into an ink supply container. A set of molded plastic check valve bodies snap-fit onto the lower end portions of the concentric tubes, and reciprocation of the inner valve body within the outer valve body produces a flow of ink upwardly through the ink supply tube while excess ink returns between the inner and outer tubes.</p> |
