Rotary printing press using flexible plates

Abstract

To enable the printing cylinder of a rotary press, which carries printing plates, to move to and from operative proximity to an impression cylinder rotatable on a fixed axis, the respective printing cylinder bearings are eccentrically mounted on large diameter disc-like bearing carriers, each rotatable in a hole in a rigid side frame member, said holes being coaxial. Each of the bearings for an anilox cylinder that transfers ink to the printing cylinder is similarly eccentrically mounted on a small diameter circular bearing carrier rotatable in an eccentric hole in a large diameter bearing carrier. Each bearing carrier has a frustoconical edge surface tapering in one axial direction, and the hole in which it rotates has a matingly tapered edge surface to define a limit of its axial motion in said direction, at which it is confined. Cooperating abutment elements on the respective bearing carriers and the frame members are engageable to define operative rotational positions of the bearing carriers, the abutment elements on the frame members being adjustable. The large diameter bearing carriers are rotated to and from their said positions by actuators connected between them and the respective side frame members; the smaller ones by actuators connected between them and their respective large diameter bearing carriers. A drive mechanism has output elements, one for each of said cylinders, constrained to synchronized rotation on fixed axes, and each cylinder is driven from its output element through an axially expansible and contractable torque tube and universal joints at opposite ends of the torque tube, respectively connected with the cylinder and its output element. The arrangement substantially prevents all erratic cylinder motion, assuring good printing quality.