Abstract: The invention relates to a sheet transfer device, for offset printing machines which print on one side of the sheet or on both sides of the sheet of paper, having a means for adjustment to accommodate sheets of different sizes, achieving thereby an accurate register printing.The feature of the device according to the invention is a reset wheel of the sheet transfer drum which is adjustably mounted on a centering flange, on rollers rotatably mounted on eccentric pins mounted in the centering flange. The centering flange has rotatably mounted eccentrics, which bear on carrying projections of the transfer drum body, while the transfer drum reset wheel is fastened to the flange. The clearance between the reset wheel and the flange centering diameter is adjusted by eccentric pins, while at the same time the reset wheel is centered so that its gearing is precisely centered with the transfer drum axis. The clearance of the toothing of the reset wheel is taken up by take-up segments.

Abstract: A technique for correcting backlash in gears utilized in printing machines. The backlash is corrected by means of toothed segments, i.e. sections of a gear, with each segment having gear teeth of varying width, with the teeth at the center of the segment having greatest width and the width of successive teeth decreasing by 0.005 to 0.6 mm to minimum values at both ends of the segment. Each segment is positioned so that the gear teeth of proper diameter to reduce backlash are disposed next to the teeth of the gear on which the segment is mounted.

Abstract: A gripper mechanism for seizing the trailing edges of paper sheets on a transfer drum of a printing machine. A plurality of rollers are resiliently mounted so as to be rotationally shiftable toward the direction of movement of the paper sheet. The rollers are oriented at various oblique angles with respect to the movement direction, with rollers further from the middle axis of the transfer drum being oriented at a greater oblique angle than rollers closer to said axis.

Abstract: The present invention provides a sheet transfer cylinder for a rotary printing machine and has associated therewith a mechanism for gripping the sheets to be transferred and for turning same. The transfer cylinder is rotatably mounted in the side walls of the machine. One of the side walls is provided with a centering ring which is fixed relative to that side wall. The ring is provided with a pair of circular segments, one of which is adjustable circumferentially with respect to the ring. The transfer cylinder is provided with roller means which cooperate with the surfaces of said circular segments and which, in turn, cause the actuation of grippers carried by the transfer cylinder. Means are provided for regulating the degree of circumferential adjustment of the first of said circular segments.

Abstract: Apparatus for seizing and holding the trailing edge of a paper sheet for transfer and turn-over in a printing press. The sheet transfer cylinder is provided with a rotatable central shaft and a plurality of segment members arranged in spaced planes radial to the shaft in at least one set to provide a cylindrical circumferential surface for the paper. The apparatus comprises a first elongated rod extending through the segments of the set and journalled for rotation about its longitudinal axis, brackets fixed to the rod and extending toward the circumferential surface, and a second elongated rod journalled in the brackets for rotation about its longitudinal axis exterior of the segments. Gripper elements are carried by the second rod, and a counter-ledge or bar is carried by the brackets. The gripper elements are adapted to cooperate by mechanical action with the bar to seize the paper sheet on movement of the second rod.