PURPOSE: To facilitate the adjustment of the position of an image by disposing a plurality of gears so that they can be fitted freely on a rubber cylinder, and thereby enabling the transmission of the rotating force of a gear for adjustment to a worm wheel fixed to the rubber cylinder, through the intermediary of a gear transmission mechanism.

CONSTITUTION: When an adjusting shaft 8 is pushed in against the elastic force of an elastic spring 7 by an adjusting knob 15 for performing the adjustment of a picture under the condition that a printing machine is stopped, the gear 9 of the shaft 8 is made to engage with a gear 6 for adjustment. Accordingly, when the knob 15 is rotated while it is pushed in, the gear 6 for adjustment is rotated and thereby a spur gear 10a engaging with said gear 6 is also rotated. Consequently, a cylinder gear 5 is rotated together with a gear transmission mechanism 10 in relation to a worm wheel 12, and thereby an impression cylinder 2 is rotated. By this rotation, the positional relationship in the circumferential direction between the impression cylincer 2 and the rubber cylinder 3 is changed, and thus the adjustment of the position of the picture can be performed for printing paper fed between the two cylinders 2 and 3. Thus, under the condition that the printing machine is stopped, the adjusting shaft 8 can be pushed in to make the gears 9 and 6 with each other at any position, and the position of the picture can be adjusted with ease and in a short time only by rotating the adjusting shaft 8.