Web registration system using retrograde web movement

Means for automatically registering a paper web on a printing cylinder of a silk screen serigraphic printing machine comprising, means for feeding a web of sheet material to a printing cylinder for receiving a printed impression thereupon and with the web in contact with said cylinder at all times, indicia means carried by said web for indicating proper registration positioning for receipt of the next successive impression thereupon, first drive means including a first drive motor, for rotating said printing cylinder in one direction and thereby advancing said web to a position where said indicia means is located beyond the proper registration position, second drive means including a second drive motor, for rotating said printing cylinder in the opposite direction, retracting said web therewith, means for operatively disengaging said first drive means from said printing cylinder after each impression applied to said web is completed, means operatively engaging said second drive means with said printing cylinder for reversing said printing cylinder carrying the web therewith when said first drive means is disengaged therefrom, said first drive means remaining thus disengaged during operation of said second drive means, and scanning means for sensing said indicia when said web is retracted, said scanning means coupled to said second drive means for operatively disengaging same from said printing cylinder when said indicia reaches the proper registration position, said scanning means being located in monitoring position relative to said web and said indicia means.