Driving system for a rotary press

In driving system for a rotary press including a plurality of printing units each having plate drums with exchangeable plates, said driving system including a main shaft and a plurality of branch shafts for operatively connecting said main shaft to respective of the printing units, thereby to drive the printing units in synchronism during a printing operation, said main shaft including a plurality of axially connected shaft sections for respective of the driving units, whereby it is necessary periodically to disconnect drive of respective of the printing units by said main shaft and to stop selected of the plate drums to enable exchanges of plates thereof, each printing unit having respective clutch means for disconnecting drive of said main shaft to the respective said shaft section and thereby to the respective said branch shaft, and each printing unit having a respective individual drive motor for driving said respective branch shaft upon disconnection of drive of said main shaft thereto by said respective clutch means, the improvement comprising means for, upon said disconnection by each said clutch means, ensuring that at least a selected plate drum of the respective driving unit is stopped at a predetermined position thereof to enable exchange of the plate thereof, and for, upon completion of such plate exchange operation, ensuring that the disconnected respective said shaft section is aligned with said main shaft to enable said clutch means to reconnect said respective shaft section to said main shaft, said ensuring means comprising:

• approach switch means for detecting said predetermined position of the selected plate drum;
• electromagnetic brake means operable in response to said approach switch means to stop the selected plate drum at an initial stopped position approximately at said predetermined position thereof;
• plate drum positioning means, located adjacent said predetermined position, for, after stopping of the plate drum by said brake means, moving the plate drum from said initial stopped position to said predetermined position;
• whereby exchange of the plate is possible;
• and
• main shaft positioning means for moving said disconnected respective shaft section to a position aligned with axially adjacent shaft sections of said main shaft, whereby said clutch means then can be reconnected.