Abstract: A clamping gripper for sheet-fed rotary printing presses wherein tensions produced in the paper by adhesion forces of the blanket do not react in run-on shifts of the center of a main gripper member mounted for rotation with a fit clearance on the gripper shaft. A spring is so disposed, and the bearing plane and the gripper support surface are so inclined relative to one another, that the resultant force due to the spring force, thrust and bearing load intersect the gripper finger at the transfer point.

Abstract: A resilient sheet gripper for a sheet-fed rotary printing press having a gripper shaft to which is secured a pivoting clamping member in resilient relationship with a pivotable gripper finger having a fulcrum and adjsutable biasing, is provided including a base member mounted loosely around the gripper shaft, a joint on the base member for pivotally securing the finger to the base member, a plurality of compression springs disposed on opposite sides of the gripper shaft with associated stops for adjustably pressing the gripper finger and the base member against the clamping member, and another stop which acts against the cylinder upon closure of the gripper finger thereby moving the fulcrum of the gripper finger from the gripper shaft to the joint so as to change the gripper finger lever transmission which then increases the retaining force.

Abstract: In a multi-color printing machine, a skew or slant of a picture to be printed is corrected by cocking, namely, swinging a paper-feed cylinder relative to a base impression cylinder by a unique but simple cocking mechanisms. The cocking mechanism includes a shaft holder which holds one end portion of the shaft of the paper-feed cylinder and which is pivotable about an eccentric position disposed on an imaginary line extending between central axes of the paper-feed cylinder and the base impression cylinder. The shaft holder is connected at another end thereof to an operating shaft via screw means which converts rotation of the operating shaft into the pivotal movement of the shaft holder.

Abstract: A sheet transfer drum for a recto and verso printing press having a two-piece section device, each piece being mounted on a diagonal slide, the slides being angled in opposite directions, so that the two pieces hold the two corners of the trailing edge of the sheet and stretch the corners in opposite axial directions as well as the circumferential direction of the sheet transfer drum. The stretching of the sheet is synchronized to the rotation of the transfer drum and effected by a control cam cooperating with a cam fixed to the printing press frame. The suction of the suction device is synchronized to rotation of the transfer drum by a commuting air connection between the suction device and a source of suction external to the press frame. The suction device is also adjustably mounted to the shaft of the transfer drum so that sheets of various length may be stretched.

Abstract: A remotely controllable adjusting device for elastically deforming a register rail in a substantially tangential direction of a sheet-guiding cylinder mounted in side walls of a sheet-fed printing machine, the sheet-guiding cylinder being preceded by a sheet-feeding device which accelerates the sheet to be printed to a speed greater than the peripheral speed of the sheet-guiding cylinder, and which brings the sheet into engagement with front guides of the register rail which is acted upon by the adjusting device operating against spring elements for elastically deforming the register rail includes a drive device arranged in the sheet-grinding cylinder and engaging deformingly with the register rail substantially in the longitudinal middle of the register rail, an axially adjustable profile rod having a first end for adjusting the drive device, the profile rod being disposed in the rotational center of the sheet-guiding cylinder, fixed against rotation relative to the cylinder, and having a second end accessib

Abstract: A gripper device for a printing machine for handling sheet-shaped material with a gripper shaft swivellable about its longitudinal axis and a gripper finger firmly connected to the gripper shaft so that a gripper point thereof is movable away from a gripper support when the gripper shaft is swivelled in a first direction, is initially displaceable into contact with the gripper support when the gripper shaft is swivelled in a second direction opposite to the first direction, and is capable of exerting a holding force on the gripper support when the gripper shaft is swivelled farther in the second direction, and a device for adjusting contact between the gripper point and the gripper support includes a resilient section forming a part of the gripper finger and connected to the gripper point, the resilient section having neutral fibers and formed as at least one resilient rod extending substantially in the direction of a plane determined by the longitudinal axis of the gripper shaft and by the gripper point.

Abstract: A cylinder apparatus of a sheet-fed rotary printing press having grippers which are pivotally supported inside a notch in a blanket cylinder brought into rolling contact with a plate cylinder and which is located in a vicinity of the leading edge of a printing plate on the plate cylinder, wherein phases of rotation of the plate and blanket cylinders are arranged such that the leading edge of the printing plate opposes a front end of the notch formed in the blanket cylinder which is located at a slightly advanced position with respect to a leading edge of the blanket, and a cam surface of a cam for opening/closing the grippers is shaped in such a manner that the grippers are kept opened when the leading edge of the printing plate opposes the front end of the notch formed in the blanket cylinder.

Abstract: A sheet gripper assembly for a sheet-fed rotary printing press having a gripper tip with a non-resilient pressure element fastened to the gripper tip by a layer of resilient material, the pressure element having a central protuberance, extending through the resilient layer, upon which the gripper tip bears.

Abstract: A clamping device of a plate cylinder for recessed in-line varnishing in a rotary press which comprises two axis-parallel clamp bars having a top part and a bottom part, which are circumferentially adjustable in a parallel or an inclined relationship to one another in guides by means of clamp screws bearing against the plate cylinder, and which are axially adjustable by means of axial setscrews, and having a groove extending over the entire length of the clamp bars in the bottom part which provides for the insertion and fixing of reinforced bent ends of the blanket, and the top part is pivotally and slidably connected to the bottom part by locking devices and recesses for the clamping screws, and additional centering means are provided for at least two of the clamping screws.

Abstract: Apparatus for clamping printing plates for rotary printing presses, having one or more clamping strips which are arranged so that they are laterally displaceable in a cylinder recess, which grip under an end region of the plate to be clamped and whose outer contour has a curvature corresponding to the cylinder curvature and is bordered by a pressure surface which engages a bent-over edge claw of the plate to be clamped, an insertable, resilient strip being inserted between the pressure surfaces of the clamping strips and a compression strip which is adjustable radially with respect to the cylinder circumference, wherein the clamping strip is adjustable in the clamping direction of the printing plates by means of two or more hydraulic cylinders which are supported at their rear and on the adjacent cylinder wall.

Abstract: A rotary printing press includes a printing plate mounted around a plate cylinder. The printing plate is in the form of a pair of semi-cylindrical resilient substrates. Each substrate is mounted to the printing plate by forming a multiple bend on the non-printing area of the leading edge of each substrate and mechanically locking the multiple bend to the printing plate.

Abstract: A device for driving an oscillating auxiliary gripper of a printing press includes an eccentric shaft rotatably mounted in the side upright of the press and on the eccentric portion of which a cam-actuated auxiliary gripper shaft is rotatably mounted for oscillation thereon rotation with a driven gear being rigidly secured to the eccentric shaft and meshing permanently with a drive gear that rotates with the impression cylinder of the press is arranged to provide positively cooperating drive elements and coaxiality of the input and output shafts for introducing the desired additional motion superimposed upon the continuous rotation of the lifting eccentric of the auxiliary gripper.

Abstract: Apparatus and a method of using that apparatus to electrostatically pickup and retain a master onto a dielectric substrate is provided. The dielectric substrate can be a flexible web with a conductive coating applied to one surface on which the master is retained. The master has an exposed permanent latent image therein.

Abstract: A process is described in which an oscillating gripper unit is utilized, having a gripper foot for the oscillating gripper member carried angularly fixed by the respective control shaft; during the return stroke of the gripper unit from the rotating cylinder of the printing machine towards the table carrying the sheets, the gripper foot is turned eccentrically with respect to the axis of its control shaft making this latter turn with appropriate means in a directional sense in concordance with that of the rotation of the whole unit in such a way as to produce a raising of it with respect to the gripper member such as to carry it out of the path of this latter while the axis of oscillation of the unit is maintained stationery with respect to that of the cylinder.

Abstract: This invention is an infeed mechanism for a sheet fed printing machine comprising a chute for guiding a sheet from a staging position into an array of moving grippers. To improve the reliability and accuracy of placement of the sheet leading edge into the gripper throat, a plurality of flexible strips, each longer than the one above, is attached to the chute bottom edge facing the grippers, the strips coming into sequential resilient contact with the open gripper fingers. The strips therefore become a flexible extension of the lower edge of the chute and serve to constrain the sheet lead edge movement into the moving gripper fingers regardless of instantaneous mechanical misalignments and sheet imperfections.

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 wrinkle-preventing mechanism for a high-speed printer, in which the web constituting the printing medium passes between skewed image and pressure cylinders while being subjected thereby to a high pressure, includes a flat-surfaced, rigid pressure pad underlying the web path toward the nip of the cylinders, a skewed, freely rotatable, elastomer-surfaced drag-inducing roller for pressing the web over its entire width against the pressure pad, and a loading system for applying forces to the roller to provide the requisite loading across the entire width of the web. A skew angle for the drag-inducing roller of about 2.degree.-5.degree. relative to the perpendicular to the direction of movement of the web toward the nip is preferred.

Abstract: A resilient sheet gripper for a sheet-fed rotary printing press having a gripper finger resiliently connected to a clamping member secured to a gripper shaft is provided including prestressed spring strips for connecting the gripper finger to the clamping member with each spring strip having articulation points disposed along a line passing substantially through the axis of the gripper shaft.

Abstract: A resilient sheet gripper for a sheet-fed rotary printing press having a clamping member secured to a gripper shaft and a pivoting gripper finger resiliently connected to the clamping member by an adjustable compression spring is provided, including eccentric bushings mounted on the gripper shaft, the gripper finger being journaled thereon, so as to impart a positive gripper closing movement substantially perpendicular to a gripper support.

Abstract: A resilient sheet gripper for a sheet-fed rotary printing press having a gripper shaft to which is secured a pivoting clamping member in resilient relationship with a pivoted gripper finger having adjustable biasing provided by compression spring means, is provided including an adjusting screw mounted in a stop strip, an abutment for contacting the screw mounted for movement around the gripper shaft, a guide pin fixed to the abutment and disposed in a biased conical sleeve in the gripper finger so that the finger can move perpendicular to a gripper support upon closure of the gripper finger.

Abstract: A resilient sheet gripper for a sheet-fed rotary printing press having a gripper shaft and a gripper finger disposed in a recess of a cylinder of the printing press and including an asymmetrical four-pivot mechanism having the gripper finger as one of its links for governing the motion of the gripper finger and ensuring perpendicular closing of the tip thereof with respect to a sheet engaged on a gripper support at the edge of the recess.

Abstract: A sheet feed drum for transferring sheets in a rotary printing press wherein the drum other contour is provided with an ink-repellent coating and two circumferentially spaced front and rear drum edges defining a duct therebetween which accommodates a sheet gripper system. The ink-repellent coating supporting a netting-like fabric relatively loosely thereon prevents any smearing of a freshly printed underside of a sheet during sheet feed on the drum while the sheet is engaged by the gripper system. Starting at the front edge of the drum, the outer contour of the drum is constructed in the form of a continuously increasing signal merging into a fixed drum radius whereby the netting-like fabric is contactable by the freshly printed underside of the sheet on the sprial first substantially flatly behind the front edge of the drum and then in any subsequent angle of rotation of the drum without the sheet tangent ever being bent or creased.

Abstract: Register of sheets being transferred by a reversal drum (9), having suction grippers (16) to grip the trailing end (15) of a sheet (12) being transported and reversed between two printing stations (1, 2) is improved and assisted by positioning pricking pins (17) in or on the suction grippers (16), to prick into and engage the trailing end portions of the sheet being picked off an impression cylinder (5) of a first printing system (1) by the reversal and transport drum (9).

Abstract: A device for engaging articles of varying thicknesses includes an anvil defining a gripping surface, a gripper finger assembly, and a finger actuator means for pivoting the gripper finger assembly with respect to the anvil. The gripper finger assembly includes a gripper finger, a finger support, and a spring which engages the finger and finger support and spring biases the finger into a neutral position with respect to the finger support. The finger may be moved out of its neutral position in either direction when forces in excess of predetermined forces are applied to the finger.

Abstract: A mechanism for clamping the leading edge of a sheet to be wrapped around a printing drum for printing in a plurality of colors includes a clip that is movably mounted in the drum so that it can be moved between an open position and a clamping position, the clip being biased to its clamping position. One or more deflectable cams are positioned adjacent to the drum for engagement by the clip. When the drum is rotated in its direction for printing successive colors on the sheet, the clip deflects the cam and remains in its clamping position. However, when the drum is rotated in the opposite direction to discharge a printed sheet, the clip is engaged by the cams and wedged thereby to its open position thereby releasing the printed sheet. The mechanism also includes provision for automatically discharging the printed sheet from the drum to a discharge path adjacent to the drum when the clip is opened.

Abstract: To reliably hold a sheet in a rotary sheet-fed offset printing machine, a plurality of pin or needle-like projections (11), preferably held on a holding strip (12), are located transversely just behind or beneath the grippers. The sheet is pressed against the pins by the rubber blanket of the blanket cylinder, to impale the sheet on the pins; or, if the projections are located beneath the grippers, the grippers indirectly apply pressure on the sheet to impale the sheet on the projections. In another embodiment (FIG. 6), a pressure block (13) with a resilient engagement surface (14) presses the grippers on the sheet for also impaling the sheet on the pins or needles. The projections may also be formed as knife edges (FIG. 4). Alternatively, the printing line can be shifted forwardly (FIG. 5), so that the rubber blanket will engage the ends of the grippers.

Abstract: A numbering device for an offset printing press including a slide mechanism. The slide mechanism includes a pair of slide plates fixed to frames of the numbering device and two pairs of rollers fixed to frames of the main machine, wherein the slide plates are received between respective pairs of the guide rollers such that the numbering device can be slid towards and away from the main machine. A first gear is mounted on a drive shaft of the main machine, while a second gear is mounted on a numbering impression cylinder of the numbering device. The two gears are engaged when the numbering device is slid towards the main machine and disengaged for the opposite direction of movement of the numbering device. A detent mechanism is provided for fixing the numbering device in either the engaged or disengaged positions of the gears.

Abstract: A sheet gripper for the delivery system of a printing machine or the like includes a clamp member adapted to be secured on a pivotable gripper shaft, and a gripper finger mounted resiliently on the clamp member and adapted to be brought into contact with a sheet to be gripped during pivoting of the gripper shaft. The clamp member is made of two sheet-metal parts and includes a base member and a bottom part, which are adapted to be hooked into engagement with one another on one side of the shaft and connected together by a mounting screw on the other side of the shaft to secure the clamp member on the gripper shaft. The gripper finger is also secured on the base member at one end by means of the mounting screw and is adjustable by means of a set screw threadably received in the base member approximately at the other end thereof.

Abstract: A printer has a drum with at least one slot for receiving sheet-like record carriers. The slot extends into the circumference of the drum and is dimensioned to receive clamping means for holding the record carrier with a clamping fit. The control of the clamping means is effected, for example, by means of disks which are secured adjacent the end faces of the drum and whose circumference is also engaged by the clamping means. The disks are provided at their outer side with a first stopper element, which resiliently co-operates with a second stopper element secured to the housing of the device in such a manner that upon rotation of the drum in the printing direction of rotation one stopper element slips over the other and upon rotation of the drum in opposite direction prevent the rotation of the disk. Thus, the clamping means are passed out of the slot.

Abstract: In a sheet-fed printing press for the purpose of separating a sheet of paper adhereing to a peripheral surface of an impression cylinder, air is supplied to an interface between the peripheral surface of the impression cylinder and the paper clamping surface of a gripper support, from a source of supply through a pair of arcuate stationary air valves on both ends of the impression cylinder and an axial air passage near the peripheral surface of the impression cylinder.

Abstract: A plurality of adjustment screws are supported on an adjusting device mounted in a recess in the outer periphery of a cylinder of a sheet-fed rotary printing press, and threadedly extend through an adjustment bar extending axially of the cylinder. A gripper pad bar on which gripper pads are mounted is disposed radially outwardly of the adjustment bar in contact therewith. The gripper pad bar and the adjustment bar are held against each other through their contact surfaces which are complementarily slanted. Rotatable movement of the adjusting screws causes the adjustment bar to displace the gripper pad bar radially outwardly or inwardly for stepless adjustment of the height of the gripper pads in conformity with the thickness of a sheet of paper without having to remove the gripper pad bar and other parts.

Abstract: A master sheet carrier which has a bar capable of holding the master sheet by clamping an end thereof, the bar being mounted on a mounting beam which is movable angularly and transversely with respect to the direction of movement of the master carrier, without requiring removal of the clamped master end, by manual operation of thumb nuts located to one side of the surface of the carrier over which the master is laid.

Abstract: A printing plate is secured to the printing cylinder of an offset printing machine by clamping bars which are installed in the cylinder channel and carry gripping strips serving to hold the edges of the printing plate. The front edge of the printing plate is provided with cutouts for the tips of feelers forming part of electronic measuring devices which are mounted on the guide strips of the printing cylinder. The cutouts have a fixed relationship relative to images on the printing plate. The clamping bar for the front edge of the printing plate is adjustable with reference to the printing plate by tightening screws until the measuring devices indicate that the front edge is in zero position. The measuring devices thereupon indicate any deviations of the position of the printing plate from zero position with reference to the printing cylinder.

Abstract: A front lay device for a sheet-fed rotary printing press comprising a feed table, a stop shaft disposed downwardly of a front end of the feed table and reciprocably angularly movable about its own axis, a stop holder mounted on the stop shaft and having a stop located adjacent to the front end of the feed table, a swingable hold-down member pivotably mounted by a pivot shaft on the stop holder and having a hook-shaped distal end disposed adjacent to the front end of the feed table, a cam shaft rotatable in synchronization with the stop shaft for driving the swingable hold-down member, and a link shaft drivable by the drive shaft for reciprocable movement about its own axis.

Abstract: A paper holding mechanism on the cylinder of a cylinder screen printing machine said paper holding mechanism being formed by clips which are controlled by a stationary cam by means of which the clips can be swung in and out of the operative position as well as by a rotating cam controlling the opening and closing of the clips which cam rotates with a speed such that during a complete working stroke and return stroke said cam has made two revolutions, said rotating cam having two opposite cam surfaces by means of which the clips can be moved against the cylinder surface so that also during part of the return stroke the clips do not extend outside of the cylinder surface.

Abstract: To permit axial excursion of the gripper spindle (2) with respect to the shaft (6) of a transfer drum or printing cylinder upon bend-through of the shaft, a spindle axial alignment element (13) is located approximately centrally of the gripper spindle (2) which is axially maintained in position by being engaged, at both axial sides, by guide rollers (14, 15) secured to the shaft (2). Thus, the gripper spindle is axially aligned with respect to the shaft essentially at the center thereof. The axial alignment element (13) in form of a plate between the rollers (14, 15) is shorter by a distance (d) than the radial distance between the shaft (6) and the gripper spindle (2) to permit radial excursion of the shaft (6) which occurs particularly at high printing speeds, thereby preventing transfer of forces on the gripper spindle (2) upon bend-through of the shaft (6).

Abstract: A sheet gripping arrangement of a rotary printing machine has a sheet gripper abutment member, a soft gripper seat member, a gripper shaft having a gripper shaft pivot point, a sheet gripping element including a gripper finger cooperating with the gripper seat member and eccentrically pivotable relative to the gripper shaft about a gripper finger pivot point so as to move first over a substantially flat gripping path and then to move during its final movement phase normally to the latter, and a threaded abutment member arranged in the finger member and acting against the sheet gripper abutment member, wherein the gripper finger member is arranged at an angle of substantially 90.degree. to a contact point of the threaded abutment member with the sheet gripper abutment member, to the gripper finger point, and to the gripper shaft pivot point.

Abstract: A cylindrical drum of a rotary transfer conveyor rotates below an opening at the bottom of a magazine for a stack of superimposed sheets. The drum carries a first pivotable gripping lever and one or more second pivotable gripping levers. The common pivot axis of the levers is parallel to the axis of the drum, and the levers are pivotable by cams so that their speed relative to the magazine is less than the peripheral speed of the drum during travel immediately below the opening in the bottom of the magazine. At such time, a set of suction cups flexes a portion of the lowermost sheet of the stack through the opening and between the first and second gripping levers so that the speed of the engaged sheet need not be immediately accelerated to the peripheral speed of the drum but merely to the relatively low absolute speed of the levers.

Abstract: A driving mechanism for groups of operating elements arranged in a rotary sheet guiding cylinder of a sheet-fed printing machine includes a pair of control shafts arranged in the guiding cylinder parallel to its axis of rotation and being driven by transmission gears arranged in the cylinder, two sets of cams, each supported on an assigned control shaft for activating a group of operating elements in a selected operational mode of the machine, and clutch means provided between the transmission gears and the shafts and operated from one point to actuate one control shaft and deactivate the other control shaft.

Abstract: A folding device for printed continuous webs moving at a high rate of speed. The device includes a pair of cooperating rolls between which the web passes. The rolls carry "working boxes" on the surfaces thereof to perform various folding functions on the moving web. Here the function of concern is the gripping of the web. An element on one roll causes the web to be pushed into open gripping elements on the cooperative roll. A bight is formed in the web at the position of gripping. During the concurrent rotation of the rolls the grippers close on the formed bight. Subsequently it is desired to remove the bight from the opening gripping elements. Simultaneously with the opening of the gripping elements there is provided a positive means for raising the formed bight out of the scope of the jaws. This bight stripper prevents any unnecessary entanglements of the fast moving printed web with the gripping elements during the folding of the web.

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: In a transfer cylinder for perfector printing machines having two diametrically opposed sheet-supporting surfaces formed from two groups, respectively, of sheet supports engaging comb-like one within the other, one of the two sheet-supporting groups of one sheet-supporting surface having a device for gripping the leading edge of a sheet, and both of the sheet-supporting groups forming one sheet-supporting surface being adjustable relative to one another about the rotary shaft of the transfer cylinder, each of the sheet supports of a respective sheet-supporting surface being firmly connected to a diametrically opposing sheet support of the other sheet-supporting surface and being disposed on the shaft of the transfer cylinder, the improvement therein includes means for mounting together at least a plurality of the diametrically opposing, mutually firmly connected sheet supports so as to be radially adjustable.

Abstract: A feed assembly for feeding sheets seriatim from a position of register on a feed table to an impression cylinder in a printing press which includes a pre-gripper having an oscillating connection with the press drive for periodically swinging the pre-gripper from a sheet pick-up position at the front edge of the table to a sheet-releasing position at the surface of the impression cylinder. The pre-gripper has a jaw and a jaw lever for opening and closing the jaw. A gripper operating cam is arranged in the path of movement of the jaw lever as the pre-gripper oscillates back and forth, the oeprating cam being mounted for retreating and return movement to control the opening and closing movement of the jaw. A rotating control cam coupled to the press drive has a control cam follower with a linkage for connecting the same to the gripper operating cam for controlling its retreating and return movement so that the jaw is closed upon an awaiting sheet at the pick-up position.

Abstract: In a transfer cylinder for perfector printing machines having two diametrically opposed sheet-supporting surfaces formed from two groups, respectively, of sheet supports engaging comb-like one within the other, one of the two sheet-supporting groups of one sheet-supporting surface having a device for gripping the leading edge of a sheet, and both of the sheet-supporting groups forming one sheet-supporting surface being adjustable relative to one another about the rotary shaft of the transfer cylinder, each of the sheet supports of a respective sheet-supporting surface being firmly connected to a diametrically opposing sheet support of the other sheet-supporting surface and being disposed on the shaft of the transfer cylinder, the improvement therein includes means for mounting together at least a plurality of the diametrically opposing, mutually firmly connected sheet supports so as to be radially adjustable.

Abstract: Camless drive of an oscillating pregripper feeder for a sheet-fed rotary printing machine having a feed table, an impression cylinder and an oscillating pregripper feeder disposed between the feed table and the impression cylinder, the camless drive including a seven-bar linkage transmission system, the bars of which are articulatingly connected to one another solely by pivot joints, two cranks connected to the transmission system and revolvable at the same angular velocity for driving the transmission system, one of the linkages forming at least part of a pregripper of the oscillating pregripper feeder, the one linkage being disposed directly behind one of the cranks, the oscillating pregripper feeder having means for gripping a sheet to be printed which lies on the feed table, and the seven-bar linkage transmission system being actuatable by the cranks for transporting the gripped sheet along a given path directly to the impression cylinder.

Abstract: Continuously rotatable advance gripper drum assembly for sheet-fed rotary printing machines having an advance gripper drum and a gripper bridge movable relative to the drum includes a crank-driven linkage transmission device disposed on and rotatable with the drum and operatively connected to the gripper bridge for moving the gripper bridge.

Abstract: A sheet gripper for a sheet-fed rotary printing machine is disclosed. The sheet gripper is secured directly to the oscillating gripper shaft of the impression cylinder of the printing machine and includes a gripper finger having a gripper tip, a gripper base, and a connecting gripper side. A hinge joint assembly between the sheet gripper and gripper shaft is formed by a shoulder on the gripper and a notch on the shaft. Alternatively, the shoulder may be provided on the shaft and the notch formed in the gripper. The gripper is secured to the shaft and is biased toward the shaft by suitable springs or the like. An adjustment assembly is provided to adjust the distance between the gripper tip and an abutment surface on the cylinder.

Abstract: To permit reversal of sheets having extended length, a sheet storage or sheet transfer drum in engagement with a sheet reversal drum is formed with a sheet displacement apparatus located on the sheet storage drum rearwardly--with respect to the direction of rotation thereof--of the gripper means of the sheet storage drum and operable to lift a sheet off the circumference of the storage drum; the sheet displacement means preferably is a rail extending axially across the width of the storage drum which can swing from a circumferential position on the storage drum to an extended position, under control of a fixed cam thus, effectively, shortening the length of the overlap of a sheet on the storage drum on the circumference thereof and permitting handling of longer sheets thereby. The extension of the sheet displacement means is carried out at a position when the displacement means are out of engagement or interference with any adjacent cylinder.

Abstract: A lithographic sheet-fed press having an impression cylinder with a gap formed in the surface thereof and having a cooperating blanket cylinder having bearers at its ends. A pair of auxiliary short bearer members bridge the gap in the impression cylinder, presenting arcuate edges for engagement with the bearers on the blanket cylinder, the bearer members are arranged at such radial height that when the blanket cylinder rolls into the region of the gap the force of printing pressure between the cylinders is taken over by the auxiliary bearer members to maintain the transaxial pressure between the cylinders substantially constant throughout the revolution thereby avoiding the cyclical impact accompanying sudden build-up of printing pressure at the end of the gap.

Abstract: Transfer drum for a sheet-fed rotary printing press includes a pair of spaced support discs mountable on a shaft of the printing press, a drum shell peripherally secured to the support discs and having an outer surface, a blanket reinforced with fabric plies and tautly covering the outer surface, the fabric plies being subjected to tensile force acting in a given direction, the blanket having two ends, and means for securing the ends of the blanket to the drum shell, the fabric plies being elastic in the given direction of action of the tensile force.