Abstract: A hydraulic drive for a multi-color, sheet-fed rotary printing machine assembled of a plurality of consecutively arranged press units each having a set of sheet-processing cylinders and gear trains interconnecting the cylinders, is constituted by the following combination:a plurality of constant-flow, radial piston type hydraulic motors directly connected for driving a cylinder in each press unit;a first hydraulic control means including a main directional control valve and an auxiliary or switching directional control valve connected between the source of pressure fluid and the hydraulic motors; anda second hydraulic control means including a control cylinder-and-piston unit assigned to each operational radial piston of the motors and controlled by the latter so as to overlap in the cross-over position of the motors both the intake port and the discharge port for working fluid.

Abstract: Method and device for positioning application rollers and printing cylinders in the printing machine during the operation with reduced machine numbers of revolutions occuring during the slow-down operation, tipping operation or hand operation, in which a precise transmission of the torque to printing units and thus accurate development of predetermined angular rotation steps is possible due to the fact that a portion of the torque of the whole initial breakaway torque is applied directly to each individual printing unit and the remaining portion of the torque required for positioning of printing cylinders and application rollers is produced by an auxiliary drive.

Abstract: A printing machine which has a plurality of printing units each including several rollers is equipped with a gear train which drives at least one roller of each of the printing units. At least associated two of the gear wheels of the gear train are coaxially mounted on a common shaft, one of them being movable toward and out of contact with the other gear wheel for establishing entraining connection therewith and for permitting angular displacement of the associated gear wheels relative to one another, respectively. The angular position of the associates gear wheels is to be changed when the mode of operation of the printing machine is to be changed from first page printing mode to first and second page printing mode. The arrangement which connects and disconnects the associated wheels includes a plurality of moving units which simultaneously act on the other gear wheel and which are mounted on an annular clamping element mounted on the other side of the one gear wheel from the one gear wheel.