| 摘要 |
In a printing machine operable for printing selectively on one or on both sides of a sheet, the printing machine having a sheet-turning drum provided with grippers actuatable by control cams and follower rollers cooperating therewith, the control cams and follower rollers being shiftable relative to one another, a device for reversing the operation of the grippers includes control elements carrying the follower rollers, and a tool insertable into the sheet-turning drum so as to project well beyond the periphery thereof, the tool cooperating with the control elements so as to lift the follower rollers from the control cams during shifting of the control cams and the follower rollers relative to one another. |
