| 摘要 |
Device for protecting a printing machine, selectively operable in a first-form printing mode and in a perfector printing mode, against damage thereto when changing over from one to the other mode of operation thereof, the printing press having a sheet-storage cylinder and a sheet turn-over cylinder cooperating therewith, respective means on each of the cylinders for gripping a sheet being printed, means includes control cams and a gear segment turnably cooperating therewith for controlling the sheet-gripping means of the storage cylinder during change-over of the printing machine from one mode of operation to the other, and means for turning the storage cylinder per se into a respective changeover position, the device for protecting the printing machine includes means for securing the turn-over cylinder against rotation while the storage cylinder is being turned by the turning means, electromechanical means for ensuring that the control means for the gripping means of the turn-over cylinder is in the respective end position thereof, and electrical switching means cooperating with the electromechanical means for monitoring the occurrence of the turning of the gear segment and turning of the storage cylinder. |
