| 摘要 |
<p>An improved printing press (10) has a plurality of printing units (12, 14, 16, 18) which are operable to sequentially print on opposite sides of a web. A drive assembly (22) is provided for transmitting force to rotate print cylinders in each of the printing units. The drive assembly (22) includes a drive line (26) which extends along the printing units. The drive line (26) is formed by a plurality of rotatable and axially aligned drive shafts which are interconnected by coupling units. The coupling units are resiliently flexible to accommodate axial movement between the drive shaft without interrupting rotation of print cylinders. A gear train (84) is associated with each of the printing units to transmit power from the drive line to the printing unit. A phase control assembly (106) is provided to incrementally rotate the printing cylinders in one printing unit relative to the printing cylinders in the other printing unit to obtain the desired registration between the images printed by the printing units.</p> |
