Control mechanism for grippers of a sheet delivery device

An automatic control mechanism for grippers with a control cam on a sheet delivery device, particularly on a printing machine, responsive to changes in speed of the printing machine, wherein the paper sheets delivered from the printing unit are carried by grippers to a sheet delivery table and are released by the grippers to be stacked on a pile of sheets, which comprises a control cam fixed on a holder which is shiftably mounted on a guide, and adjustably mounted on a control screw;

• a carrier arranged on said control screw to allow turning of said control screw but to prevent axial movement of said control screw with respect to said carrier;
• a pull rod pivotally mounted at one end to said carrier and at the other end to one end of a carrier lever which is turnably mounted at its other end on a pivot means in a side wall of the printing machine, said pivot means being provided at one end with a swing lever which is fixed to a variator, said variator having a moveable pulley member for varying the driving speed of the printing machine and being arranged to rotate said pivot means responsive to changes in the speed of said printing machine, thereby causing said carrier lever to pivot, changing the position of said pull rod, said carrier and said adjusting screw, whereby the position of the paper release is changed in relation to a change in speed of operation of the printing machine by means of said variator.