Printing arrangement alternatively operated for one-side printing and two-side printing with control system therefor

In a printing arrangement operative in a first mode for printing on only one side of a sheet and operative in a second mode for printing on both sides of a sheet, of type comprised of drive means for effecting transport of a sheet to be printed along a predetermined path through the printing arrangement, further comprised of a plurality of printing devices cooperating to effect printing of a sheet passing along said path, and further comprised of means operative for effecting a changeover from one to the other of said modes in a manner altering a portion of and changing the length of said path, a control system for the printing arrangement, comprising, in combination, a shift register having a plurality of shift register stages and having a shifting pulse input for receipt of shifting pulses and having an information signal input for receipt of information signals;

• means for applying to said information signal input a predetermined signal in response to the arrival of a sheet at a predetermined location along said path;
• shifting pulse generating means synchronized with said drive means and operative for applying to said shifting pulse input a train of synchronizing shifting pulses causing said predetermined signal to be registered by successive ones of said shift register stages in synchronism with the travel of the sheet along said path;
• a plurality of actuating means each associated with and controlling the operation of a respective one of said printing devices and each connected to a respective one of said shift register stages and each operative for actuating the respective printing device in response to the arrival of said predetermined signal at the respective shift register stage so as to control the operation of the respective printing device in a manner correlated with the arrival of the sheet to be printed at the portion of said path associated with the respective shift register stage;
• and compensating means operative upon a change of operating mode for at least partially offsetting changes in the correlation between shift register stages of said shift register and the associated portions of said path.