Abstract: A sheet-conveying drum for use between units in a printing machine is provided with a plurality of gripper bridges arranged substantially circumferentially symmetrically on the drum surface. The gripper bridges hold the paper to the drum and include gripper impact strips that are adjustable radially relative to the drum in order to accommodate printing materials of different thickness. Each gripper impact strip is adjusted by means of a positioning device that is arranged on the drum radially inward of the gripper impact strip and mounted so that it can move axially relative to the drum and cam the gripper impact strip radially. The axial movement of each positioning device is brought about by an actuating device which is preferably a pneumatic cylinder and is disposed on the body of the drum at the free end of each positioning device. An energy supply sequentially actuates each actuating device resulting in the piston of each cylinder either extending or retracting.

Abstract: A throw-on and throw-off device for a blanket cylinder in the printing unit of an offset press is provided wherein two parallel double-acting fluid pressure cylinders connected to the blanket cylinder via a toggle-like linkage can be individually supplied with compressed air either consecutively or simultaneously so that, in the first case, precise sequential throw-on of the blanket cylinder on the plate cylinder and subsequently on the impression cylinder can be achieved and, in the latter case, there can be a very rapid throw-off of the blanket cylinder from both the impression cylinder and the plate cylinder. Compressed air energization of the two pressure cylinders is triggered by a control unit in accordance with the position of grip edge zones of the blanket, plate and impression cylinders being in registration.

Abstract: A sheet-conveying drum for skew register correction in multicolor printing that does not affect the drive in sheet-fed rotary presses. The sheet-conveying drum comprises gripper bars and support or carrying webs that are disposed on a drum shaft. The web disposed nearest the drive input has on its flange an arcuate bearing surface around which the drum body can be skewed relatively to the drum shaft. The web disposed opposite the drive input is coupled to an adjusting eccentric bushing by way of a flange to cause the drum to skew. The movements of drum skewing do not adversely affect the drive and, therefore, the transmission ratios of the sheet-guiding cylinders relative to one another.

Abstract: A throw-on and throw-off device for a blanket cylinder in the printing unit of an offset press is provided wherein the blanket cylinder is mounted at both its ends in eccentric bushings and the pivoting throw-on/throw-off movement of the bushings is produced by a toggle-like linkage. Two parallel double-acting fluid pressure cylinders are connected by way of their piston rods to a cross link which is pivoted to one of the links of the toggle linkage. The two pressure cylinders can be individually supplied with compressed air either consecutively or simultaneously so that, in the first case, precise sequential throw-on of the blanket cylinder on the plate cylinder and subsequently on the impression cylinder can be achieved and, in the latter case, there can be a very rapid throw-off of the blanket cylinder from both the impression cylinder and the plate cylinder.

Abstract: A radially adjustable gearwheel for driving a cylinder of an offset press. The gear rim has a peripheral annular groove opening axially outward and dimensioned to receive a tensioning ring including inner and outer body parts engaging each other along an inclined tapered surface. A plurality of tensioning devices are mounted on the gear rim and act axially on the tensioning ring causing the inclined surfaces of the inner and outer body parts to slide against each other resulting in radial displacement of the outer body part which produces radial deformation of the gear rim.

Abstract: In a sheet-fed offset press having at least one printing unit in which the blanket cylinder can be thrown on and off the impression cylinder and plate cylinder by a pressure-medium-energized actuating arrangement, the pressure medium energization is triggered by a control unit in accordance with the position of grip edge zones of the cylinders being in registration. In order to ensure that throwing on and throwing off take place when the grip edge zones of the cylinders are positioned immediately opposite one another, the control unit detects the position of the printing unit cylinders relatively to one another by way of an angular position sensor and also detects the actual speed of the press via a speed sensor. The control unit forms speed-dependent throw-on and throw-off actuating times which are advanced in the direction of rotation of the printing unit cylinders so that the reaction time is outside the time slot for grip edge zone registration.

Abstract: A device for cleaning the working surfaces of a plurality of cylinders in a printing press is provided wherein a plurality of pressing elements are disposed each for selective engagement with the working surface of at least one of the cylinders and a web of cleaning cloth is disposed to move successively over the pressing elements and is selectively urged by the pressing elements into relative rubbing contact with the working surfaces of at least two of the cylinders. A drive for stepwise advancing and arresting the movement of the cleaning cloth with respect to the pressing elements and the working surfaces of the cylinders includes a clean cloth spindle disposed transverse to the stepwise movement for supplying said web of cleaning cloth and a stepwise drivable dirty cloth spindle disposed parallel to the clean cloth spindle and adapted to receive the used cleaning cloth.

Abstract: A device the for in-register transfer of sheets and for the conveyance thereof between the printing units of a multi-color press by means of gripper carriages that move on rails and which are driven by an endless chain and which are aligned on the delivery and feed cylinders by rotating drive forks and that cooperate with a cam roller carried by the carriage. For joint axial and radial alignment with quiet entry the drive fork has leading and trailing flanks of different thicknesses and the flanks are guided into engagement with the cam roller by hardened guide plates in the gripper carriage. The leading flank is undersized and the second flank has the dimension necessary for establishing proper registration of the carriage.

Abstract: A device for controlling the opening of a plurality of sheet grippers in a sheet-fed rotary press wherein the grippers are arranged to form a row on a gripper shaft disposed on a rotating cylinder. The gripper shaft is centrally controlled between its ends by two cam control systems acting in parallel relationship on the ends of an actuating shaft, by turning of the latter, with a central adjusting means interconnecting the actuating shaft and the gripper shaft to provide a symmetrically divided torsional force adjustable to vary the opening width of the grippers according to the sheet thickness being processed.

Abstract: A vertically adjustable gripper support mechanism for the grippers of turning drums of perfecting presses wherein the sheet is turned by two correlatively cooperating gripper systems disposed on cam-controlled pivot shafts biased by return springs. An adjusting shaft is disposed concentrically within the pivot shaft and is rotatable by an adjusting wheel, the adjusting shaft being formed with axially spaced recesses corresponding to the number of gripper supports and having a plurality of arcuate adjusting surfaces preferably offset at 60.degree. in the peripheral direction to one another to provide a multistep vertical adjustment to the gripper support.

Abstract: A cutting assembly for a sheet fed printing machine having a feed drum for supporting individual sheets and feeding them one after another to the impression cylinder for printing by the blanket cylinder, including a knife blade having a cutting edge, a knife blade support, an arm for mounting the support adjacent the feed drum, the arm being pivoted about an axis parallel to the axis of the feed drum for limited rocking movement toward and away from the feed drum, a stop and a clamp for establishing a reference cutting position for the arm, the feed drum having an anvil extending around its periphery cooperating with the edge of the knife blade for cutting of the sheet as the feed drum rotates, way surfaces between the knife blade support and the arm for guiding the knife blade support for movement in the plane perpendicular to the feed drum and along a path of adjustment which bears a shallow angle to a line of tangency to the feed drum, and a manually operated adjusting screw effectively interposed between

Abstract: A sheet-fed rotary printing press having lower and upper blanket cylinders in running engagement with an impression cylinder to form nips accessible through an access space. The driving means for the cylinders includes an inching circuit and a drive enabling circuit. An interlock switch adjacent the access space is connected in the drive enabling circuit. A safety subassembly and a washing subassembly are provided with quickly disengageable means for mounting the subassemblies in position successively in the access space. The safety subassembly includes a guard plate having a normal position in which the plate closes off the access space and forms a sheet guide. A first disengageable linkage couples the guard plate to the interlock switch so that when the plate is in its normal position the enabling circuit is enabled for normal driving of the press and so that when the guard plate is absent from its normal position the press is limited to inching movement.