PURPOSE: To prevent generation of plays among members by freely rotatably disposing a lever in one of two members to be brought close to and separated away from each other, providing a hooking part or the free end of the lever and linking these members by engaging this with the receiving part of the other member in its pressed state.

CONSTITUTION: Adjacent printing units 10 and 10 are pressed to each other, a cylinder device 4 is actuated and a lever 3 is rotated in a direction for engaging with a receiving part 6. At this time, since the curvature center P2 of the receiving part 6 is fixed by being slightly shifted by only a distance X from the rotational center P1 of the lever 3, when the lever 3 rotates in a direction for engaging with the receiving part 6, a space 9 is first generated between a roller 50 and the circular arc surface 61 of the receiving part 6, when the lever 3 further rotates, the roller 50 is abutted on the circular arc surface 61, and when the lever 3 still further rotates, the roller 50 is gnawingly engaged therewith. Thus, the adjacent printing units 10 and 10 are linked together in a pressed state and no play therebetween is generated.