Abstract: A device for stabilizing sheet guidance in a sheet-processing machine includes a first transport device having first gripper devices for guiding sheets to be processed, and a second transport device having second gripper devices opposing the first gripper devices. The first gripper devices are in cooperation with the opposing second gripper devices, during an operation selected from the group of operations consisting of taking over and transferring the sheets. The opposing second gripper devices are dippable into interspaces formed between the first gripper devices, and at least one supporting element is disposed in the interspaces for supporting leading corners of the sheets, the supporting element being disposed locally fixed on the first transport device. The opposing second gripper devices are disposed in a region of the supporting element and include a forked gripper formed with a cutout into which the supporting element is dippable during transfer of a leading edge of the sheet.

Abstract: A device for preventing a spring-loaded control roller from being lifted off a control cam therefor in a gripper control system in a sheet processing machine, includes a support mechanism disposed separately from the gripper control system. The support mechanism impresses an additional force upon the control roller in critical regions.

Abstract: A printing-machine cylinder includes a basic cylinder body and a covering element fitted to the basic cylinder body, one of the basic cylinder body and the covering element being formed with a multiplicity of recesses connectable to one of a suction-air source and a blast-air source and having, in the region of the recesses, through-channels extending from the recesses to the peripheral surface of the covering element and defining blasting/suction sections for acting upon the underside of a sheet conveyed on the peripheral surface of the cylinder; a printing machine Including the cylinder; and a method for producing the cylinder.

Abstract: A device for changing an operating state of a gripper-control device in a sheet-reversing device of a sheet-processing machine including a cylinder having an actuating shaft accommodated therein, includes an activating element cooperatively engaging with the actuating shaft for changing the operating state of the gripper control device. An actuating element is coupled mechanically with the actuating shaft. An adjusting element is movable relative to the cylinder. The adjusting element is disposed externally to the cylinder and cooperatively engages with the actuating element for moving the actuating element at least approximately synchronously with the cylinder during operation of the sheet-processing machine while the actuating shaft remains in a prescribed position with respect to the cylinder. The actuating element is changeable in position relative to the cylinder by the adjusting element, whenever the operating state is changed.

Abstract: A device for feeding suction air or blowing air to a sheet-retaining device displaceable relative to a machine element in a sheet-processing machine, includes a first air-feeding element connectible in terms of flow to a suction-air or blowing-air source. A second air-feeding element cooperates telescopically with the first air-feeding element for forming an air through-passage duct connected in terms of flow to the sheet-retaining device.

Abstract: A device for transferring sheets in a sheet-processing machine includes a cylinder having at least one gripper device for the sheets, and a control device for opening and closing the gripper device, the control device having a first control cam for recto printing and a second control cam for recto/verso printing, at least one follower element for following the first and second control cams, each of the first and second control cams being formed with a through opening for accommodating a bearing element and, respectively, a cutout formed in the periphery of the first and second control cams and extending as far as the through opening for fitting the first and second control cams to and removing them from the bearing element radially. The first and second control cams, respectively, are of unipartite construction and, in peripheral direction, are aligned with one another so as to provide an at least approximately closed contour path for the at least one follower element.

Abstract: A recto and verso printing press, comprising an upper gripper and a lower gripper, respectively, centrally pivotable with respect to an introduction of force, said upper gripper, in recto printing position thereof, being cooperable with a gripper pad fixed to a cylinder of the printing press, said upper gripper and said lower gripper being arranged centrally in relation to one another and to said gripper pad, and having a common center line.

Abstract: A method for taking over a sheet by a trailing edge thereof from an upline cylinder of a sheet-fed rotary printing press and transferring the sheet by the trailing edge thereof to a gripper system, by placing a suction gripper on the sheet in a marginal region of the trailing edge and, during the sheet takeover, having the suction gripper follow the periphery of the upline cylinder, having the suction gripper guided at a constant tangent into the periphery of a downline inverting drum and, along this course, having the suction gripper execute a relative motion in the direction of the tangent so as to tauten the sheet, which comprises, upon reaching a transfer position at the gripper system, having the suction gripper execute a relative motion in the sheet transport direction and, when the grippers close, having the suction gripper and the gripper system disposed at rest relative to one another; and a transmission system for performing the method.

Abstract: A device for fixing the position of a sheet includes a feeding table for transporting the sheet; at least one front lay disposed in vicinity of the feeding table and, in a working position, protruding upwardly beyond the plane of the feeding table; a swivellable holder to which the front lay and an adjusting device for the front lay are secured; and a adjusting device secured to the holder, the front lay and the adjusting device being disposed separated from one another on the holder, the front lay being in continuous biasing engagement, under tension, with the adjusting device, so that, by changing the position of the holder, the front lay and the adjusting device are movable from the working position into a neutral position and, conversely, from the neutral position into the working position.

Abstract: A device for transferring sheets in a sheet-processing machine includes a cylinder having at least one gripper device for the sheets, and a control device for opening and closing the gripper device, the control device having a first control cam for recto printing and a second control cam for recto/verso printing, at least one follower element for following the first and second control cams, each of the first and second control cams being formed with a through opening for accommodating a bearing element and, respectively, a cutout formed in the periphery of the first and second control cams and extending as far as the through opening for fitting the first and second control cams to and removing them from the bearing element radially. The first and second control cams, respectively, are of unipartite construction and, in peripheral direction, are aligned with one another so as to provide an at least approximately closed contour path for the at least one follower element.

Abstract: A suction gripper for transferring a trailing edge of a sheet guided on an upstream sheet-conveying cylinder to a downstream sheet-conveying cylinder of a turning device of a sheet-fed rotary printing machine includes a holding arm. The holding arm can be extended out of the circumferential surface of the downstream sheet-conveying cylinder, to which a suction head is movably fastened. The suction head is connected to the holding arm via a spring and its movement in a direction toward a circumferential surface of the upstream sheet conveying cylinder is limited by a stop.

Abstract: A device for transferring to a downline sheet-guiding cylinder of a reversing device in a sheet-fed rotary printing machine, a trailing edge of a sheet guided on an upline sheet-guiding cylinder, includes at least one lifting device for lifting the trailing edge of the sheet from the upline sheet-guiding cylinder, and a gripper device disposed on the downline sheet-guiding cylinder, the gripper device having a gripper pad extensible out of the periphery of the downline sheet-guiding cylinder for receiving the trailing edge of the sheet from the lifting device outside the periphery, and retractable into the periphery of the downline sheet-guiding cylinder after receiving the trailing edge of the sheet, the lifting device being at least one adjustable blowing nozzle disposed in a stationary manner or on the upline sheet-guiding cylinder, for blowing air beneath the trailing edge of the sheet; and a method of transferring the trailing edge of the sheet.

Abstract: An apparatus for performing successively performable actuations in a printing press includes a pressure converter having an actuator formed with actuator surfaces which are successively able to be acted upon stepwise by pressure fluid; and a printing press in combination with the apparatus. Successively performed actuations in a printing press include switching or controlling, coupling, adjusting and tensioning operations, wherein machine or press parts are moved and/or held in a given position. Such actuations may be necessary in various devices of the printing press, a defined sequence of actuations having to be adhered to, depending upon the functions of the individual devices and to assure disruption-free cooperation of the devices. The actuations often require a transmission of comparatively strong forces to devices located at various places in the printing press which in terms of structural space are quite restricted. Pneumatic and hydraulic systems are therefore used for these purposes.

Abstract: In a reversing device of a sheet-fed rotary printing machine, there is provided a suction gripper for taking over a trailing edge of a sheet conveyed on an upline sheet-conveying cylinder, the suction gripper being movable out of a periphery of a downline sheet-conveying cylinder, gripping the sheet to be reversed in a region of the trailing edge thereof, and being movable back in a substantially radial direction towards the downline sheet-conveying cylinder for transferring thereat the trailing edge of the sheet to a further gripper device, including a device for converting the substantially radial return movement of the suction gripper into an axial movement of the suction gripper so as to tauten the sheet.

Abstract: A method for transferring, by a trailing edge thereof, a sheet conveyed on an upline sheet-conveying cylinder to a gripper device of a downline sheet-conveying cylinder in a reversing device of a sheet-fed rotary printing press, the gripper device having sheet-holding surfaces for accepting the sheet trailing edge, which comprises lifting the sheet by the trailing edge thereof from the upline sheet-conveying cylinder; moving the sheet-holding surfaces of the gripper device out of the periphery of the downline sheet-conveying cylinder; with the sheet-holding surfaces of the gripper device, accepting the sheet trailing edge outside the periphery of the downline sheet-conveying device; and moving the sheet-holding surfaces back into the periphery of the downline sheet-conveying cylinder; and a transferring device for performing the method.

Abstract: A sheet sensor arrangement for a sheet printing machine and particularly for a turning device of a sheet printing machine, which comprises at least one hollow cylindrical drum (3; 4), which has a gripper system to transport and/or temporarily store individual sheets (5). A sensor arrangement which is not very susceptible to contamination and has a mechanically simple structure is comprised of the fact that the cylindrical wall of the drum (3; 4) has at least one opening which allows light to pass through, and that a sheet sensor is formed by a light barrier (9, 10, 11), which has a light beam which, in at least one angle position of the drum, is directed from the inside at the opening which allows light to pass through. In addition, a corresponding process for optical monitoring of sheets in a sheet printing machine is indicated.

Abstract: A device for detecting mis-fed or missing sheets in a printing press having a storage drum includes a plurality of holding suction devices disposed on the storage drum and connected fluidically with one another via a first connecting line, a plurality of detecting suction devices disposed on the storage drum and connected fluidically with one another via a second connecting line, the holding suction devices and the detecting suction devices being formed with respective suction openings coverable at least partly by a sheet properly fed thereto, and a pressure monitoring device fluidically connected to the second connecting line for controlling the operation of the printing press in accordance with pressure prevailing in the second connecting line, the holding suction devices and the detecting suction devices being formed primarily of suction devices of the same type, the second connecting line having a cross section smaller than that of the first connecting line, and being connected fluidically with the first

Abstract: A sheet sensor device for a sheet-fed printing press having a sheet-reversing arrangement, said sheet-reversing arrangement being comprised essentially of a storage drum, a reversing drum and gripper systems mounted on these drums, so that a sheet sensor device comprising a transmitter and a receiver is arranged in the sheet-reversing area formed between the storage drum and the reversing drum, and that the transmitter is arranged on the one side of the printing machine, and the receiver is arranged on the other side of the printing machine, outside of the sheet-travel area.

Abstract: A cleaning device for cleaning an outer cylindrical surface of an impression cylinder of a rotary printing machine includes a cleaning cloth pressed against the outer cylindrical surface by a beam. The beam is pivotally mounted to engage the cleaning cloth with the outer cylindrical surface upon pressurization of a pneumatic cylinder. A spring pivotally returns the beam to disengage the cleaning cloth with the outer cylindrical surface upon depressurization of the pneumatic cylinder. To assure radial clearance between the cleaning device and the gripper fingers of the impression cylinder, the pneumatic cylinder is depressurized at a first angular position of the impression cylinder and the pneumatic cylinder is subsequently pressurized at a second angular position of the impression cylinder.

Abstract: An adjusting device for a gripper opening cam in a chain delivery of a sheet-fed printing press, the gripper opening cam being pivotally guided in a bearing and being connected by a linkage to one of a pair of threaded nuts of a combination of a lefthand and righthand thread of an adjusting shaft screwable into a fixedly supported other threaded nut of the combination, includes an adjusting motor with an electrical program controller programmable for adapting to parameters which vary as the printing press rpm runs up to and runs down from operating speed for automatically tracking the gripper opening cam, and a coupling operative in the adjusting device, the coupling being disposed between the adjusting motor and the gripper opening cam.