Abstract: Device for measuring contact pressure of a gripper device having a gripper member and a gripper pad in a sheet-fed rotary printing press includes a layer of piezoelectric material, one of the gripper member and the gripper pad being formed of two parts with the layer of piezoelectric material disposed between the two parts, and a device for picking-off a charge from the layer of piezoelectric material which is a measure of contact pressure between the gripper member and the gripper pad of the gripper device.

Abstract: A printer for printing characters and images on recording paper comprising: a paper cassette for storing the recording paper; a platen roller around which the recording paper is wound at the time of the transfer of images for printing; a clamping mechanism for clamping the recording paper between the clamping mechanism and the platen roller; a motor for driving the platen roller through a gear unit; a thermal printing head for transferring images onto the recording paper; a paper feeding roller for feeding the recording paper from the paper cassette to the clamper; paper discharging rollers for discharging the recording paper upon the completion of the transfer of images thereto; and an ink cassette storing an ink sheet inside thereof; in which the clamping mechanism comprises a clamper which is mounted on the platen roller in such a manner as to permit the free movement of the clamper, holds the recording paper by pushing the recording paper onto the platen roller in a first position and also releases the re

Abstract: A printing switching apparatus for a sheet-fed rotary press with a reversing mechanism includes a fixed gear, a rotary gear, a first inclined surface, an engaging member, and an actuating unit. The fixed gear is fixed to a shaft of a cylinder. The rotary gear is coaxial with the fixed gear, coupled to be driven with a cylinder adjacent to the cylinder, and phase-adjustable with respect to the fixed gear in a circumferential direction. The first inclined surface is formed on the rotary gear. The engaging member is movable with respect to the fixed gear and has a second inclined surface pressed against the first inclined surface of the rotary gear. The actuating unit moves the engaging means in a direction to be separated from or come close to the fixed gear, presses or releases the first inclined surface of the rotary gear and the second inclined surface of the engaging member against or from each other, and connects or disconnects rotational transmission between the fixed gear and the rotary gear.

Abstract: An image-transfer apparatus for producing an aesthetically fine transfer image includes a platen having a cut-off portion on the surface formed for attaching an image-forming material and a transfer cylinder having a cut-off portion on the surface formed for attaching an image receptor. The apparatus allows the introduction of the image-forming material and the image receptor into a nip formed by the platen and the transfer cylinder by the rotation of the platen and the transfer cylinder to transfer an image formed in a photosensitive layer of the image-forming material to the image receptor heated to a transfer temperature. The transfer cylinder, other than the cut-off portion, has a cylindricity of 100 .mu.m or less, a circumferential deviation, measured in the radial direction of the transfer cylinder, of 60 .mu.m or less and a straightness, measured on a cylinder surface, of 60 .mu.m or less when heated to and kept at a transfer temperature.

Abstract: A pregripper configuration in a sheet-fed rotary printing press feeds single sheets to a rotating cylinder. A cam drive includes a main cam and a roller lever which pivots about a frame-fixed shaft. A lever mechanism, which is articulated to the roller lever and a pregripper pivot arm, transmits the motion of the cam-following roller lever to the pivot arm. The pivot arm is also pivoted about a frame-fixed shaft. In order to compensate for play in the lever mechanism, a pretensioned spring is disposed between an attachment point on the roller lever and an attachment point on the pivot arm. In one embodiment, the pretensioned spring extends approximately parallel to a rigid link connected in articulated fashion between the roller lever and the pivot arm. In another embodiment, the spring is attached to a compensating cam drive.

Abstract: This invention concerns a device for remote-controlled operation of clamping elements of a turning device, especially in cylinders that carry sheets of paper and on the side walls of rotary printing presses. The turning device has at least one turning drum, one storage drum and adjustable toothed segments. These components in turn comprise clamping elements by means of which a clamp connection is created and maintained between force transmitting elements that are adjustable relative to each other and between control elements by having an initial tension force act on them. Control elements (20, 24; 46, 48) on which a hydraulic medium can act are arranged on movable pressure bars (9, 32, 39) consisting of at least one part. These move a transmission element (13, 32a, 40, 45) such that the clamping effects generated by the force storage devices (12) are cancelled out.

Abstract: A gripper assembly is provided for use within a printing press having an impression cylinder and one or more printing stations. The gripper assembly includes a main shaft, gripper clamp arms mounted to the shaft, and gripper blocks mounted to the shaft in alternating sequence with the gripper clamp arms. Each of the gripper blocks includes a projection overlying a portion of the adjoining gripper clamp arm. A spring is positioned between each projection and adjoining gripper clamp arm for urging the gripper blocks about the axis of the shaft. A gripper is mounted to each of the gripper blocks. Each gripper has a generally flat, Z-shaped body, one end of which is adapted for engaging a sheet of paper. The main shaft is coupled to a cam follower for causing rotation of the main shaft, thereby opening or closing the set of grippers.

Abstract: Gripper control for sheet grippers on a sheet-guiding cylinder or the like in a printing press, wherein a stationary pressure generator for a pressure medium is connected by means of a coupling, through the intermediary of a motor-actuated servo-valve, to a sheet-gripper actuating system disposed on the cylinder or the like and, through a control system, being acted upon by the pressure medium in time with an operating cycle of the printing press, includes a piston-cylinder unit forming part of the actuating system, a displacement-measuring system connected to the piston-cylinder unit, respective elements for pivotally connecting the piston-cylinder unit, at one end thereof, to the sheet-guiding cylinder or the like and, at the other end thereof, to a lever connected to the sheet gripper, the control system including a programmable control computer connected by measuring lines to the displacement-measuring system and, via a position-control loop, being capable of controlling a motor-actuated positioning of th

Abstract: Clamping device for locking a printing plate on a cylinder of a printing press includes two parallel clamping bars formed with respective clamping surfaces, at least one of the clamping bars being movable perpendicularly to the clamping surfaces, and an element for producing a clamping force between the clamping bars, a first one of the clamping bars including at least one leaf spring formed with the clamping surface of the first clamping bar, the clamping surface thereof being cooperatively clampable with the clamping surface of the second one of the clamping bars, the first clamping bar further including a member formed with at least one concave segment-shaped recess, the leaf spring being formed with a corresponding convex segment-shaped protrusion supported in the recess.

Abstract: Sheet-fed rotary printing press for making one-sided multi-color prints or recto-and-verso prints, having at least one multi-size, driven sheet-guiding cylinder disposed between impression cylinders of two printing units, devices adjustable to a sheet-length format, and gripper systems associated with the cylinders, includes at least two intermediate gears via which a drive of the cylinders is divertable, at least one of the intermediate gears being formed as a single-revolution double intermediate gear having an adjustable ring gear and a gearwheel.

Abstract: A rotating print medium retaining clamp is disclosed which securely clamps the print medium or printed image final receiving surface to prevent horizontal or X-axis misregistration while drawing the print medium in a generally circular path through the nip between the platen and the print head. Only the retaining clamp assembly rotates while the support guide remains stationary. The support guide has space for a printing platen to be positioned along the print medium guide path.

Abstract: Clamping and tensioning device for an inwardly bent trailing edge of a flexible printing plate disposed in an axial gap at the circumference of a plate cylinder adjustable in axial spacing and cooperating with a blanket cylinder, the printing plate being fixable at a leading edge thereof on the plate cylinder and being tensionable in circumferential direction on the plate cylinder, includes two clamping bars displaceably supported in the axial gap and forming therebetween a clamping slot for receiving therein an inwardly bent trailing edge of the printing plate, the two clamping bars extending axially in the gap within the cross-sectional contour of the plate cylinder and being loadable by reversible opposing clamping forces as well as by reversible tensioning forces in common in tensioning direction of the printing plate, and being respectively braced against the plate cylinder, the two clamping bars being formed with radially outer edges, the clamping and tensioning device being radially displaceably dispos

Abstract: Swivelling pre-gripper of a sheet-fed printing press having a sheet feeding table includes a swivel arm; a gripper carried by the swivel arm; a mutually cooperating roller lever and cam mechanism for, respectively, opening and closing the gripper; a device for cyclically swivelling the swivel arm of the pre-gripper to and away from the sheet feeding table; a device for cyclically opening and closing the gripper; a device for setting an instant of opening of the gripper for releasing a sheet gripped by the gripper in a closed condition thereof to a downline conveying device for accepting and transporting the released sheet; a device for setting, in a manner decoupled from the setting of the instant of opening, an instant of closing the gripper for gripping the sheet fed from the feeding table to the pre-gripper; one of the devices for setting the instant of opening and for setting the instant of closing of the gripper being disposed on the roller lever; and the other of the devices for setting the instant of c

Abstract: A device for transporting sheets within a printing machine in which the sheets are conveyed by gripper carriages which are articulated on endless chains driven by chain wheels. A transfer of the sheets between the gripper carriages and a sheet-guiding cylinder takes place in the region of the chain wheels. The chain wheels, around which the chains are guided do not have a continuous shaft, but are attached to the opposing ends of short stub shafts which are mounted rotatably in the frame side walls of the printing machine. Attached to the other ends of the stub shafts stubs are gear wheels which mesh with gear wheels attached to the two journals of the sheet-guiding cylinder in order to synchronize the chain wheels with the sheet-guiding cylinder. A feed and take-off transport device of this type operates in such a way that a freshly printed sheet or a sheet provided with varnish coating can be transferred to and/or removed from the sheet-guiding cylinder in a smear-free manner.

Abstract: Gripper apparatus on a sheet-processing machine includes a pair of cooperative gripper members, a control device including a computer for controlling the pair of gripper members, at least one data transmitter connected to the computer for inputting data therein, and at least one mechanism for performing at least one function selected from a group thereof consisting of opening and closing the pair of gripper members in response to an output of the computer, the function-performing mechanism being operatable at predetermined positions of the sheet-processing machine.

Abstract: An image forming apparatus includes a drum gear having a first guide slot and a cam, a clamp having a first interlocking pin inserted into the first guide slot and a cam pin is interlocked with the cam. A release lever is mounted on a support plate on which a shaft of a drum is supported. A lifter having one end with a second guide slot formed therein is coupled to the first interlocking pin. The other end of the lifter has a second interlocking pin interlocked with the release lever. The apparatus can shorten the overall printing time by reducing the additional time required for ejecting a sheet of paper because the clamp is operated in cooperation with rotation of the drum during a printing operation.

Abstract: A device for actuating a clamping device on at least one paper-guiding cylinder in a rotary printing press, including a positioning unit having a device for applying a pressure medium thereto, a lever mechanism cooperatively engageable with the positioning unit, a device for remotely controlling a clamping device on a respective paper-guiding cylinder through the intermediary of the lever mechanism, the clamping device having a clamping bar and a device for actuating the clamping bar into a clamping mode and into a nonclamping mode, the actuating device being cooperatively engageable with the positioning unit, and spring devices for maintaining the clamping bar in the clamping mode wherein a cylinder covering is clamped thereby on the respective cylinder.

Abstract: A sheet gripper assembly includes a gripper shaft clamping member which is securely attachable to a gripper shaft. A gripper housing that includes a gripper arm and a gripper finger is secured to the gripper shaft clamping member through an elastic member. This elastic member provides a resilient or springy attachment of the gripper housing to the gripper shaft.

Abstract: A printing machine plate cylinder having a plate tensioning slide rail adjustably mounted within a hollow of the cylinder. The slide rail is supported by a plurality of roller ring modules which stably support the slide rail and permit easy and exact movement of the slide rail in any direction in the adjusting plane.

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: An apparatus for stretching a cylinder blanket on a sheet transfer cylinder of a sheet-fed printing press includes a tiltable member mounted on the cylinder. A first end of the blanket is first attached to the cylinder in a cylinder groove, the blanket is wrapped around the cylinder, and the second end of the blanket is attached to the tiltable member, while the tiltable member is in an open position. The tiltable member is then closed to stretch the blanket about the cylinder, and locked into the closed position to maintain the blanket about the cylinder.

Abstract: A sheet reversing assembly for a rotary printing press utilizes one or more arcuately and radially movable gripper assemblies on an impression cylinder to elevate a gripped leading edge of a sheet to be reversed. As the trailing edge of the sheet is engaged by suction grippers on a reversing drum, air blast jets in the vicinity of the abutment surface of the gripper assembly direct air under pressure between the sheet and the surface of the impression cylinder.

Abstract: A chain operated sheet transport and transfer mechanism for sheet-fed printing machines having a plurality of printing units. The chain operated mechanism includes a plurality of gripper cars affixed to chains for movement between the printing units. The gripper cars each have a gripper impact strip and a pivotable gripper finger, with the gripper strip of each car extending the width of the gripper car and being of concave configuration. A bending device at the transfer zone of each printing unit is operable for acting on the gripper car to bend the concave gripper impact strips straight in order that sheets are transferred from one printing unit to the other without register deviation.

Abstract: In a delivery section of a sheet-fed printing press convertible between single-sided sheet printing and first-form and perfector printing, a sheet guide is provided formed with a sheet guide surface alterable between conditions wherein the surface is formed with throughholes and the surface is continuous and smooth, and a device for altering the sheet guide surface so that it is formed with throughholes when converting the press from first-form and perfector printing to single-sided sheet printing, and for altering the sheet guide surface so that it is continuous and smooth when converting the press from single-sided sheet printing to first-form and perfector printing.

Abstract: A sheet-gripper device for sheet-fed rotary printing presses formed of a sheet gripper and a sheet-gripper seat, the sheet gripper comprising a sheet-gripper head and a gripper screw-on part, the sheet-gripper head being held by friction in the gripper screw-on part so as to be swivellable about a longitudinal axis of the sheet gripper.

Abstract: A device for positioning printing material for use in a printing apparatus in which printing is applied to the printing material by passing the same through between an impression cylinder and a blanket cylinder, the device comprising positioning member disposed in an recessed portion formed on an outer surface of the impression cylinder, the positioning member including, a stopper with which a leading end of the printing material comes to contact, drive means for moving the stopper forward and backward in a direction of transport of the printing material, control unit for controllably driving the drive means while the impression cylinder is being rotated, and operation means for operating the control means. Accordingly, displacement of superimposed printed images in a direction of transport of the printing material resulting from the fact that the positioning member improperly positions printing material can be corrected rapidly and accurately.

Abstract: A sheet transport drum utilizes a plurality of drum peripheral envelope surface elements which are each secured to spaced apart disks. Each of these drum envelope surface elements has a plurality of vacuum chambers which are supplied with vacuum in a circumferentially sequential manner. A sheet to be transported by the sheet transport drum is smoothly attracted to the drum's outer perforated envelope plate without wrinkling or buckling.

Abstract: A paper guide cylinder utilizes an outer cylinder shell and an interior dynamically balanced cast body. A pair of axle journals are formed at the ends of the cylinder body. At least one of the axle journals is adjustably supported concentrically with a bearing journal that is formed with the outer cylinder shell.

Abstract: An electric or electronic sheet control device is provided at a sheet-transferring cylinder of a printing machine. According to the state of the art, in order to detect a leading edge of a sheet, two detecting elements respectively detect the presence of a sheet and a misaligned sheet. According to the invention, two detecting elements are disposed in such a way that they detect at least the outer areas of a leading edge of a sheet and at least one further detecting element is provided between the two detecting elements, which makes it possible to detect whether or not the leading edge of the sheet is straight.

Abstract: A gripper finger for a gripper spindle in a sheet-fed printing press includes first and second components. The first component has a gripper finger extension which contacts a gripper finger support at a transfer point. The first and second components cooperate to form an enclosure angle for enclosing the gripper spindle, with the first component contributing a maximum of 180 degrees to the enclosure angle and the second component supplementing the enclosure angle. The second component is fastened to the gripper spindle. A first compression spring is disposed between the ends of the first and second for exerting an adjustable, first spring force approximately in a direction of the transfer point. An adjustment screw is threadably engaged with one of the components and has a tip which lies against the supporting plane of the other component for exerting a screw force approximately in a direction of the transfer point.

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 drum for transporting sheets includes a drum base body having a plurality of sheet leading edge grippers and a sheet trailing edge holding part. A plurality of movable suction nozzles are used to smooth the sheet on the surface of the drum and the drum base body and holding part are shiftable circumferentially to stretch the smoothed sheet so that all wrinkles and other defects will be removed from the sheet.

Abstract: A quick-action clamping device for fastening a printing plate on a plate cylinder in a printing machine by a fixed clamping bar and a displaceable clamping bar which are able to be brought into a clamping position and a plate-changing position, respectively, includes a spring device for resiliently pressing the displaceable clamping bar into the clamping position with a holding force for clamping a printing plate between the displaceable clamping bar and the fixed clamping bar, and at least one re-set element for returning the displaceable clamping bar to the plate-changing position against the holding force.

Abstract: A suction transfer actuation system for a transfer drum of a multi-color sheet-fed rotary printing press for turning successive sheets, by rear-edge turning, during the sheet transfer from one printing unit to another to facilitate printing on the back side of the sheets. A plurality of suction arms are rigidly connected to a hollow suction rocker shaft connected to actuating levers carrying guide rollers engaging curved guide cam surfaces on a guide bar mounted on the transfer drum. The suction actuation system is driven by way of a cam rigidly mounted on the press frame engaged by a cam follower roller to oscillate a drive lever coupled by a link to a drive arm on the rocker shaft to rock the suction arms toward and away from the one printing unit under the guiding influence of the guide cam and guide rollers.

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 suction transfer actuation system for a transfer drum of a multi-color sheet-fed rotary printing press for turning successive sheets, by rear-edge turning, during the sheet transfer from one printing unit to another to facilitate printing on the back side of the sheets. A plurality of suction arms are rigidly connected to a hollow suction rocker shaft connected to actuating levers carrying a pair of guide rollers engaging a curved outer guide cam surface on a guide bar mounted on the transfer drum. The suction actuation system is driven by way of a cam rigidly mounted on the press frame engaged by a cam follower roller to oscillate a drive lever coupled by a link to a drive arm on the rocker shaft to rock the suction arms toward and away from the one printing unit under the guiding influence of the guide cam and guide rollers.

Abstract: A platen roller apparatus having a cylindrical platen roller, a recording sheet retaining member capable of moving while being maintained in parallel with the axis of the platen roller, a positioning member for positioning a recording sheet on the platen roller; and members for urging the recording sheet retaining member inwardly in the radial direction of the platen roller. The recording sheet is retained while being pinched between the outer circumferential surface of the platen roller and the recording sheet retaining member.

Abstract: A delivery apparatus which minimizes marring of wet ink is provided with an arcuate main wall and a gap forming leading and trailing edges. The leading edge can be positioned, either temporarily for adjustable versions, or permanently for nonadjustable versions, radially inward to shorten the path of a sheet exiting the last set of blanket and impression cylinders in a printing press. By shortening the sheet path, marring of wet ink against the delivery apparatus is reduced. The delivery apparatus is mounted onto a gripper bar sprocket shaft such that the gap receives the respective gripper bar. As the shaft rotates to move the gripper bar, the delivery apparatus also rotates. The outside surface of the delivery apparatus has a myriad of minute projections with rounded outer ends and being of a uniform height, which outer surface contact the wet ink side of the sheet.

Abstract: A device for smoothly applying a sheet for printing onto an impression cylinder upstream of a printing gap of a sheet-fed rotary offset printing machine in travel direction of the sheet through the printing machine and including at least one jet nozzle capable of being directed towards the circumference of the impression cylinder for pressing the sheet by blowing air force against the circumference, comprising drive means for swingingly reciprocating the jet nozzle in travel direction of the sheet during an operating cycle of the printing machine, the jet nozzle being mounted at a spaced distance and upstream from a printing gap and being swingable in a pendular manner about a pendulum axis extending parallel to an axis of the impression cylinder, the jet nozzle being couplable with the drive means.

Abstract: A swinging gripper apparatus for use in a sheet-processing machine, which includes a rocker arm member having a pivotally mounted first end and a second end which is selectively positionable adjacent the cylinder or adjacent the feed table, a cam segment member having two opposing arcuate camming surfaces provided thereon, apparatus for moving the cam segment member closer to or further away from the pivotally mounted first end of the rocker arm member, at least one gripper member pivotally mounted on the second end of the rocker arm member for pivotal movement with respect thereto, a lever arm extending from the at least one gripper member, and a cam follower member mounted on the lever arm, the cam follower member being positioned between the two opposing arcuate surfaces provided on the cam segment member.

Abstract: A method and device for continuously feeding blanks for the formation of hard cigarette packs, whereby the blanks are withdrawn successively from the bottom opening of a feedbox and fed on to the outer periphery of a conveyor roller by means of mobile suction heads guided cyclically by crank mechanisms along a route having a portion substantially perpendicular to the bottom opening of the feedbox, and a further portion substantially tangent to the periphery of the conveyor roller and which further route portion is followed by the suction heads at a speed substantially equal to the surface speed of the conveyor roller itself.

Abstract: A thermal ink-transfer printer for printing a color image on a paper wound along a platen roller in the manner where a thermal head is pressed against the paper and an ink film interposed therebetween so that ink on the ink film is melted by the thermal head. The printer comprises clamp mechanisms having supporting rings and clamp levers for holding an end of the paper against a holding member, clutch mechanisms having clutch rings and clutch levers for fixing the clamp mechanisms and platen roller in a start positioning mode and a printing mode, and a controlling element for coupling the clutch mechanisms with the platen roller in a paper feeding mode and a paper ejecting mode. As the clamp mechanisms hold the supplied end of the paper and the platen roller and the clamp mechanisms have their rotation individually controlled, it is possible to prevent color off-registration in color printing.

Abstract: A gripper finger for a sheet gripper system for a printing press, to which gripper unwanted paper dust, dirt, debris, or the like cannot stick, the profiled retaining surface of the finger has in its front part a single bead-like protuberance which contacts the sheet, has a bead radius (R) of from 0.4 to 1.0 mm, extends parallel to the front edge of the sheet and is coated with a hard substance.

Abstract: A transfer or delivery cylinder for a sheet-fed rotary printing press having an endless chain conveyor carrying gripper bars and grippers and driven by a sprocket wheel concentrically mounted on a drive shaft for pulling freshly printed sheets from the impression cylinder onto the transfer or delivery cylinder for movement to a further processing station within the press, wherein the transfer or delivery cylinder is a right circular cylinder eccentrically mounted to the drive shaft so that upon initial engagement of the freshly printed sheet by the grippers, the leading edge of the cylinder is spaced below the sheet which is thereafter pulled smoothly and uniformly into contact tangentially with the sheet support surface of the transfer or delivery cylinder.

Abstract: A printer for printing out information on a paper wound around a drum and having a device for feeding and discharging a paper sheet from the drum and a clamping pawl which is provided on the drum to selectively clamp and unclamp the leading edge of the paper sheet. The paper feed and discharge and the clamping and unclamping of a paper sheet performed by the feeding and discharging device and the clamping pawl, respectively, are implemented by a single reversible stepping motor, clutches which are disposed in gearings which individually transmit the rotation of the stepping motor to the paper feeding and discharging device and the clamping pawl.

Abstract: In a sheet-fed rotary printing press, a sheet gripper has a gripper finger and a gripper support, the gripper finger being swingable, in operating phase with the printing press, under the action of a gripper spring, into engagement with the gripper support and, against the action of the gripper spring, out of engagement with the gripper support, the gripper spring being supported at one end thereof against a counter-bearing on the gripper finger and, at the other end thereof, against a counter-bearing on a gripper housing, and includes a holding device separable from one another for fixing at least one of the counter-bearings, the holding device being in mutual agreement and being disposed on the counter-bearing as well as on a part of the printing press wherein the counter-bearing is mountable, the separable holding device being formed of an inner locking part and an outer locking part of a bayonet lock, at least one of the locking parts having projections and the other of the locking parts having holding su

Abstract: A grip shaft is supported on a cylinder that makes an oscillating (reciprocating rotational) motion. The grip shaft is provided with a grip for holding a printing material. The grip is further provided with a cam follower. A cam is positioned along the path of motion of the cam follower, and the cam follower engages with an opening portion of the cam when the grip is right before a printing material feeder portion, and opens the grip. Further, when the grip reaches the printing material feeder portion, the cam follower moves to a closing portion of the cam, closing the grip to hold a printing material. After the grip has held a printing material, the cam follower disengages from the cam as the cylinder is rotated in the opposite direction. The opening portion and the closing portion composes a continuous cam surface.

Abstract: A paper clamping mechanism for clamping a sheet of printing paper on a drum-shaped platen of a printer is disclosed. The mechanism comprises a clamp member radially slidably mounted at its legs to the end surfaces of the platen, and a lever pivotted to the frame of the printer. The clamp member comprises a pressor which opposes an axial recess on the peripheral surface of the platen; the front end portion of a sheet of paper is held between the pressor and the recess during the printing operation, the clamp member being urged toward the axis of the platen by a spring. The clamp member further comprises an axially extending pin formed on a leg thereof. The lever is urged by a spring to a position at which it is stopped by a pin formed on the frame of the printer. An arm of the lever comes into contact with the pin on the leg of the clamp member when the clamp member is rotated with the platen.

Abstract: A sheet clamping system for rotatable drums especially suited for use in retaining and positioning successive receiver sheets for high speed printers. The clamping system enables unidirectional movement of a sheet during delivery of the sheet to the drum from a supply stack, during clamping of the leading edge of the sheet to the drum followed by clamping of the trailing edge of the same sheet to the drum and during subsequent release and delivery of the sheet to a receiving stack or tray. The system features a cam system for actuating respective leading and trailing edge clamps which is supported on the same shaft to which drum driving rotation is supplied by a drive motor. In one embodiment where the drive motor is reversible, a one-way clutch connection of the drum to the shaft enables drum rotation during one rotational direction of the shaft whereas clamping bar actuation is effected by rotation of the shaft in the opposite direction while holding the drum.

Abstract: A sheet turn-over assembly includes at least one cooperating pair of first and second sheet gripper sets. Each set has coacting sheet gripper fingers and sheet gripper abutment surfaces. These fingers and abutment surfaces in each set are carried on coaxially aligned rotatable shafts. Movement of one shaft with respect to the other accomplishes sheet gripping and release. Movement of the coaxial shafts of each gripper set with respect to the cooperating set accomplishes sheet turn-over.