Abstract: A device for in-register positioning of a printing plate for mounting it on a plate cylinder of a printing press, includes at least two positioning pins engageable for in-register positioning exactly in recesses formed in a printing plate leading edge, and sensors for detecting the exact engagement and for transmitting a corresponding signal, at least one positioning pin and at least one recess on one side of the printing plate leading edge having noninterchangeable engagement positions in relation to at least one positioning pin and at least one recess on another side of the printing plate leading edge which is opposite to the one side thereof with respect to a center line of the printing plate.

Abstract: Coordinate positions of openings and lands on a screen and a first circuit board are recognized by a recognition camera and a display device. A correction amount for movement of the stage is calculated by a control device only for the first circuit board. Then, the correction of movement of the stage is executed for the second and following circuit boards by utilizing the correction amount.

Abstract: The present invention is directed to a web fed rotary printing press which can perform a printing plate change on the fly, while preventing the printing plate from touching an associated moving blanket cylinder. In accordance with exemplary embodiments, a nip roller is used to securely press the printing plate toward the plate cylinder during printing plate replacement, such that only a small gap exists between the stopped plate cylinder and the moving blanket cylinder. As such, the entire printing unit need not be modified to account for ink train cylinder movement.

Abstract: There is disclosed an apparatus for identifying a page of printing plate or printed product. The apparatus comprises reading head means for reading out at least one of items in a local descriptive portion of the page of printing plate or printed product. The apparatus further comprises identifying means for identifying the page of printing plate or printed product in accordance with the read out data transmitted from the reading head means.

Abstract: A system for accurately registering multiple silkscreens relative to a printing surface after they have been clamped into a silkscreen holder of a printing head of a rotary screen printing machine, and for accurate placement of an image on a framed silkscreen. A generally L-shaped registration device attached adjacent to one side of a pallet of the printing machine has first and second sides orthogonal relative to each other with a pair of gauges having visual displays positioned on the first side and a third gauge positioned on the second side. The gauges have outwardly biased plungers controlled by a lever to be simultaneously moved between a retracted positioned, a free-floating position and an engaged position relative to respective first and second sides of a silkscreen frame.

Abstract: The several screen frames of a multistation screen printing machine, such as a carousel screen printer, having multiple work supports movable to the printer stations in succession to effect successive printing of screen images on work pieces fixed to the supports are precisely registered with the work supports by providing each frame with registration features precisely located relative to the screen image on the frame, providing a selected work support with registration features precisely located relative to the printing position of a work piece on the selected support, effecting movement of the selected work support to the print stations in succession, adjusting the corresponding screen frame to directly align its registration features with the registration features on the selected work support, and securing the frame in fixed position.

Abstract: A system and method for controlling registration between different printing plates or printing cylinders in a printing press which includes a camera with a lens having at least two zoom settings and a control unit for changing the zoom setting of the camera in accordance with a distance between registration marks printed on a printed substrate found in at least one image acquired by the camera.

Abstract: A press arm (110) including a mounting plate (112) and a clamp support (116) for support of a print screen, and one or more independently mounted intermediate components (134, 136, 180, 184, 214, 216, and 228) that provide for independent adjustment of clamp support (116) in each of six ways: lateral adjustment in the X-, Y- and Z-axis, and angular adjustment in the X-Y plane, the X-Z plane and the Y-Z plane. Various threaded adjustment bolts and releasable clamps are provided for making each of the independent adjustments.

Abstract: The invention relates to a method and device for positioning a flexible printing plate in a desired position on a flexible carrier arranged on a table, the method comprising the steps of placing the printing plate at a first easily accessible position on the table and subsequently moving the printing plate from the first position to the desired position on the flexible carrier in accordance with a predetermined direction and distance; and wherein the device comprises a flat table, means for positioning the flexible carrier, means for determining the location of the carrier in a first easily accessible position, and transporting means for transferring the printing plate from the first position to the predetermined position on the flexible carrier.

Abstract: A spiral gear 7G formed on an adjusting bolt 7 is engaged with a spiral gear 8G disposed around a shaft 8 for diagonal adjustment. The shaft 8 is rotatably supported in a block 16 which is fixed to the bottom of the tail edge side clamping base 3, and the shaft 8 is screwed into the hole of a block 18 provided to a plate cylinder 60 and passes therethrough. The block 18 is supported so as not to be moved in the directions shown by the arrows 92, 93 relative to the cylinder plate 60. Diagonal image adjustment is carried out by moving the tail edge side clamping base 3 in the directions shown by the arrows 92 or 93 as a result of rotating an adjusting knob 7H of the adjusting bolt 7.

Abstract: A screen printing machine is provided having a cabinet, a print screen, a platen assembly, and a curing assembly. The cabinet includes an upper opening and a shelf extending inwardly along at least two opposed cabinet sidewalls. The print screen is adapted to be held on the cabinet shelf in a lateral position. The platen assembly is provided for supporting a substrate suitable for receiving a screen print. The curing assembly is movably connected to the cabinet and located generally above the cabinet upper opening. The curing assembly includes a housing having an open bottom and at least one ultraviolet bulb attached within the housing and oriented to direct ultraviolet light downward. During use, the curing assembly moves laterally between a first position in which the ultraviolet light bulb is not directly above the substrate and a second position in which the ultraviolet light bulb is located directly above the substrate. A registration system is provided having a flexible spring arm.

Abstract: A screen printing method is provided in which the exchange of machine types is achieved in a short time and even minute patterns or narrowly pitched patterns can be precisely positioned for screen printing. The method comprises finding an amount of movement of the circuit board from positions of recognition marks (2, 2) on a circuit board (1) and positions of recognition marks (5, 5) on a screen plate (4), positioning the circuit board (1) in relation to the screen plate (4) on the basis of the amount of movement of the circuit board (1), detecting a discrepancy between a pattern of apertures (18) and a pattern of lands (19) in a particular portion of the circuit board (1), finding a positional correction from the discrepancy, and positioning the circuit board (1) in relation to the screen plate (4) on the basis of the amount of movement of the circuit board and the positional correction.

Abstract: The present invention generally describes register control equipment for the cylinder of a printing machine. It specifically pertains to the printing plate of sheet-fed offset printing machine that has fitted register pins. The register pins are electrically insulated with respect to the cylinder and emit a signal when a printing plate is resting in register on one or more of the pins. The signal is communicated to a stationary evaluation unit by an electrical contact adapted to contact the printing plate. The evaluation unit uses the communicated signal to determine whether or not insertion was properly performed.

Abstract: A method for recording a rectangular image along helical tracks on a plate, while the plate is mounted on a cylindrical surface in an imagesetter, so that an edge of the image, corresponding to a reference edge of the plate, essentially parallels the reference edge. The method includes punching one or more notches across the reference edge of the plate, providing two stop pins, fixedly attached to the cylindrical surface, and positioning the plate on the cylindrical surface so that one of the stop pins engages one of the notches.

Abstract: A system for registering a work support pallet on a carousel machine arm with a screen frame of the machine has pivot components on a pallet tool and on the arm for detachable pivotable mounting of the pallet tool relative to the arm for accurate pivotal movement of the pallet tool into proximity with the screen frame.

Abstract: Machine for the silk-screen printing of flat articles such as sheets of glass (2) and the like, comprising at least four fixed uprights (10) supporting horizontal parallel beams (20) on which a bridge (30) carrying the printing means (40) is movable, and a surface (3) for resting the glass (2), said machine comprising an apparatus (100; 1000) for gripping and centring the glass (2) with respect to the fixed printing screen (4).

Abstract: A method of printing multi-color images on pressure sensitive labels carried on a web uses a disk shaped mark for each color which is printed to form the image. The disks (spots) are printed on the image, or elsewhere on the top layer of the web, with one disk being printed on top of the other, so that the marks coincide in size, shape and position. If a color is misregistered, it appears as a crescent which extends beyond the multi-colored disk. Such misregistration may be immediately viewed on a video magnifier, using at least 400.times. magnification, and the misregistration corrected.

Abstract: An exposure frame (30) and a registration printing pallet (130) are disclosed for registering a printing screen frame (10) holding a screen (12) first to the artwork (4) and next to the pallet (19) supporting the product (T) to be screened.

Abstract: In the production of a printing stencil, for example a rotary printing stencil for textile printing, for the purpose of transferring a pattern stored in an electronic memory, liquid is applied to the lateral surface of the printing stencil as it rotates. A nozzle which supplies the liquid is driven by pattern data belonging to the pattern. Pattern data situated earlier or later in the circumferential direction of the stencil cylinder are read out as a function of at least one deviation between the actual and desired positions of the lateral surface which respect to the pattern data belonging to the desired position, in order to prevent distortion of the pattern owing to the deviation.

Abstract: A screen printing machine having a rotor, a stator, a device for moving the rotor and stator into juxtaposition, and an annular track and track followers for guiding the rotor in vertical and radial directions.

Abstract: In a process and a device for adapting the position of printing plates (4) to the deformation (fan-out) of the paper web (2) to be printed through damp, ink absorption and mechanical stress on passing between several successive pairs of printing rolls (1) and also for adaptation to deformations possibly occuring in the fixing device of a printing roll (1) and resultant changes in the position of a printing plate (4), the printing plate (4) and/or the mount holding it in the stamping or bending machine (5) is moved or shifted laterally, in the circumferential direction and/or angularly by the amount required for said printing plate (4) on the printing roll (1) owing to said deformation of the paper web (2) to be printed, in order to obtain a print corresponding with a preceding printing roll (1), as considered in the direction of feed of the paper web, despite the paper deformation that has meanwhile occured. Thereafter the deformations, i.e.

Abstract: The present invention relates to a control means for a printing machine, in particular a sheet-fed offset printing machine, having a plurality of units, such as feeders, printing units, varnishing and coating devices, deliverers, folding apparatus and the like, each unit being assigned a station having at least one computer and these stations being connected to one another via a first bus. It is intended to ensure that the switching processes which are to be carried out in the individual units of the printing machine at specific, predetermined angle positions can proceed exactly, even at the highest machine speeds. According to the present invention, for this purpose it is proposed that, in addition to the first bus, via which the stations exchange signals with one another, a second bus is provided, via which the individual stations may be fed with the angle position signals of a single-turn rotating angle encoder which is fitted on one unit of the printing machine.

Abstract: An apparatus and method for mounting a plurality of plates onto a carrier sheet includes a table mounted on a stationary base, each plate having a first and a second registration mark thereon. A first camera assembly is moveably attached to a support adjacent the table and is connected to a first video monitor for viewing the first registration marks. A second video camera is moveably attached to the support adjacent the table and is connected to a second video monitor for viewing the second registration marks. Linear actuators are connected to the first and the second camera assemblies and to the table for independently moving each camera assembly relative to the table. A motion controller is connected to the linear actuators for sending moving signals thereto, and generates at least two moving signals corresponding to the two registration marks for each plate.

Abstract: Pull lays on a feed table of a sheet-fed rotary printing machine are adjusted by a pulling device for laterally aligning sheets thereon. A spindle, which extends transversely to the travel direction, displaces the pull lays for adjusting to a sheet format to be processed. The spindle engages indirectly at a housing of the side lays which is provided with bearing and guide elements. The pull lays are thereby subject to an energy storing device which supports them in a guide transversely to the feed table.

Abstract: A detachably mounted pallet tool is utilized on the arms of a carousel printing machine and work support pallets thereon to provide a more efficient and rapid registration with stationary screen frames associated with the machine, without removal of work support pallets from the arms. A bracket on an arm and cooperating fitting on the pallet tool provide for quick, detachable mounting and removal of the pallet tool.

Abstract: The several screen frames of a multistation screen printing machine, such as a carousel screen printer, having multiple work supports movable to the printer stations in succession to effect successive printing of screen images on work pieces fixed to the supports are precisely registered with the work supports by providing each frame with registration means precisely located relative to the screen image on the frame, providing a selected work support with registration means precisely located relative to the printing position of a work piece on the selected support, effecting movement of the selected work support to the print stations in succession, adjusting the corresponding screen frame to directly align its registration means with the registration means on the selected work support, and securing the frame in fixed position.

Abstract: A system and method for controlling registration between different printing plates or printing cylinders in a printing press which includes a camera with a lens having at least two zoom settings and a control unit for changing the zoom setting of the camera in accordance with a distance between registration marks printed on a printed substrate found in at least one image acquired by the camera.

Abstract: A retractable registration apparatus is mounted on a screen printing type press for aligning a printing frame with an image platform, such as a vacuum table. The apparatus has a pair of registration pins for coupling with the printing frame and a registration appendage which carries the registration pins. The registration appendage is rotatably mounted to the printing press for rotation from a registration position to a retracted position. A locking mechanism retains the appendage with the registration pins in the exact registration position.

Abstract: Printing screens are registered using a photosensitive position locating sensor which is affixed to a pallet and aligned with the image of a register mark on the first of a series of printing screens. The location of the image is stored and signalled in a display device. The pallet is then roughly aligned with a second and subsequent screens of the series. The subsequent screens are each moved until the display image of its register mark is superimposed upon the stored image. The signal output from the sensor is applied to a microprocessor which controls the display device.

Abstract: A method and an apparatus for axially positioning a flexible plate on a surface of a cylinder, that is divided into several axially spaced segments, utilizes a plate transport arrangement to transfer plates from a plate preparation device to the plate cylinder. The plate is axially shiftable during transport and arrives at the plate cylinder in proper axial position.

Abstract: The several screen frames of a multistation screen printing machine, such as a carousel screen printer, having multiple work supports movable to the printer stations in succession to effect successive printing of screen images on work pieces fixed to the supports are precisely registered with the work supports by providing each frame with two and preferably three registration points precisely located relative to the screen image on the frame, providing a selected work support with the same number of registration points precisely located relative to the position of a work piece on the selected support, effecting movement of the selected work support to the print stations in succession, adjusting the corresponding screen frame to directly align its registration points with the registration points on the selected work support, and securing the frame in fixed position relative to its respective print station while the frame and work support are firmly held in fixed position by registration pins extending between

Abstract: An apparatus and process for making sheets having indicia spaced in a machine direction. Between or among the indicia are perforations or chop-off cuts. The spacing, in the machine direction, between the indicia and perforations or chop-off cuts is maintained over long sheet lengths. The product produced using this apparatus and process is typically paper, and particularly can be used for paper towels or placemats.

Abstract: This invention discloses an universal chuck for holding plates, including a base having a longitudinal axis and a transverse axis, a lower carriage movable on the base along said longitudinal axis, an upper carriage movable on the lower carriage along the longitudinal axis, a plate mounting carried by the lower carriage at one side thereof for mounting one edge of a plate to be held by the universal chuck, and a plate mounting carried by the upper carriage at the side thereof opposite to the one side of the lower carriage, for mounting the opposite edge of the plate to be held by the universal chuck, such that moving the lower carriage and the upper carriage with respect to each other and with respect to the base along said longitudinal axis, changes the distance between the lower carriage and upper carriage plate mountings to thereby enable the chuck to hold plates of different longitudinal dimensions.

Abstract: A method and apparatus for forming a design on a surface is disclosed. The method comprises the steps of selecting a surface on which a design is to be formed, placing a stamping device at a selected location on the surface, depressing the stamping device against the surface at the selected location so that a segment of a first portion of a design is formed, moving the stamping device to a different selected location on the surface spaced a desired distance from the initial selected location, registering the stamping device depressing the stamping device against the surface at the different selected location so that an additional segment of the first portion of the design is formed, and repeating the steps of moving the stamping device to a different location and depressing the stamping device until a desired length of the first portion of the design is completed on the surface. One or more addition design portions may be superimposed on top of the first design portion.

Abstract: A printing unit for a web fed rotary printing press for printing newspapers is provided in which the central impression cylinder (2) is commonly rotatably mounted in the two side walls (14a, 14b) of the housing (14) of the printing press and the blanket cylinder (4) and/or print cylinder (6) are rotatably cantilevered on one end in the first side wall (14a) during the make ready operation of the printing press, allowing a quick and easy changing of the cylinders (4, 6) via an opening (30) formed in the second side wall (14b). When the printing press is in operation the blanket and print cylinders (4, 6) may be additionally rotatably supported in a side plate (32) fitted to the opening (30), or may remain unsupported on their other ends.

Abstract: An apparatus for securing a screen printing frame to a printing machine for screen printing, the apparatus has a retainer for the screen printing frame and a mounting head carried by the printing machine. A plurality of adjustment mechanism are interposed between the mounting head and the retainer for screen printing frame for adjusting the retainer and the screen printing frame relative to the mounting head. At least one of the adjustment mechanisms has a sleeve having a threaded bore carried by either the retainer or the mounting head and a threaded shaft carried by the other. Rotating of the threaded shaft in the threaded bore adjust the position of the screen printing frame relative to the mounting head. The sleeve has a hole extending through the threaded bore and a pin adaptable for insertion in the hole for locating the end of the threaded shaft for use as a stop position for locating a zero position of the adjustment mechanism.

Abstract: An off-contact setup device is provided for a screen printing type machine. The setup device includes a frame that releasably clamps onto a levelled image pallet of the screen printing machine. The height of the setup frame relative to the pallet surface is adjusted. This height is calibrated to a desired off-contact distance between a printing screen and the substrate to be printed (which is positioned on the pallet during printing). The frame holding arm of the printing machine, which is used to support the screen printing frame, is brought into position and secured to the setup frame. The height and level adjustments for the screen frame holding assembly are then fixed so as to conform to the position of the setup frame on the pallet. This process is repeated for all stations on the printing machine. Thus, the relative distance between all pallets and the screen printing frames attached to the holding assemblies are set to be the same, providing a consistent printing operation.

Abstract: Apparatus is provided for aligning two objects (1,2), such as a board and screen in a screen printer, each having at least one reference mark (6a,7a) on a surface thereof, whereby alignment of the objects is indicated by alignment of corresponding reference marks on the surfaces of the objects. The apparatus comprises support means for supporting the objects in use with the said surfaces facing one another, and imaging means (20), mounted for movement between the said surfaces in use, for acquiring, on a single imaging surface thereof, simultaneous images of respective areas of the surfaces of the objects, which areas contain corresponding reference marks. The apparatus includes control means (4,8) for determining the locations of the reference marks in the images and determining therefrom the extent of misalignment of the objects, and means (3), responsive to the control means, for adjusting the relative positions of the objects to bring the objects into alignment.

Abstract: A printing cylinder system for use in a printing press comprising a unique apparatus and method for tensioning and releasing a flexible printing plate that is wrapped around a printing cylinder and clamped by a clamping mechanism disposed within the printing cylinder and accessed by a longitudinal slot. The invention features a mounting mechanism for holding the clamp mechanism in a relative position within the printing cylinder and including control means for moving the clamping mechanism within the printing cylinder substantially toward or away from the cylindrical slot to either apply tension to the printing plate or release tension on the printing plate. In a further embodiment, the invention comprises a piston assembly for pushing the edge or edges of the printing plate outwardly toward the cylindrical slot opening, upon actuation.

Abstract: Silk-screens of annular-shape are provided for the silk-screen printing of halftones on compact discs. The silk-screens are rotatably provided in a carrier so that the angle at which moire can be eliminated or at least minimized or localized for the printing of a particular color can be determined. Following the determination of that angle for each of the colors to be printed, the screens are each then provided with photosensitive emulsion, exposed to light, and washed. The silk-screens are then placed in another carrier at the same angle as before determined for the elimination or at least the mimimalization or localization of moire, this carrier being capable of being placed directly into the nest of a print head of a conventional silk-screen printing machine.

Abstract: A screen printing apparatus includes: a positioning stage for positioning an object and a plate arranged above it; printing squeegees which are moved horizontally on the plate for printing through the plate onto the object; a driver for moving the positioning stage; a horizontal driver for moving the positioning stage in two substantially perpendicular directions; a positioning controller for calculating a central position of a pattern on the plate from a reference position and the size of an outer periphery of the object, moving the positioning stage so that the central position corresponds to a center of the object. A carry-in conveyor is provided for feeding the object onto the positioning stage along a predetermined transferring direction, the conveyor being arranged away from the positioning stage and having a carry-in conveyor surface on which the object is placed before the object is fed onto the positioning stage.

Abstract: A register draw-in device for sheet printing and embossing machines has two front or leading edge stops and a side stop, and position sensors (S1, S2, S3) for detecting print marks (P1, P2, P3) of a sheet (5). Two detectors (D1, D2) associated with the front stops (A1, A2) detect the sheet leading edge. The front stops are adjustable by control elements (M1, M2) until front print marks (P1, P2) on the sheet are detected by sensors (S1, S2). A control element (M3) then adjusts the side stop (A3) until a side print mark (P3) is detected by another sensor (S3). A system control (11) controls this register correction with the position sensors (S1, S2, S3), the detectors (D1, D2) and the control elements (M1, M2, M3). This accomplishes reliable automatic register correction for each individual sheet and therefore maximum print quality.

Abstract: An offset printing method is suitable for high-precision printing. Errors caused by the relative movement between a blanket cylinder 4 and a form plate 10 and the rotation of the blanket cylinder 4 on its axis which are produced in a step of transferring an ink image to the blanket cylinder 4 from the form plate 10, are reproduced in the relative movement between the blanket cylinder 4 and a surface to be printed on 11 and the rotation of the blanket cylinder 4 on its axis in a step for printing the ink image on the surface to be printed on 11 from the blanket cylinder 4. The dimensional errors produced in the ink image transferred to the surface 12 of the blanket cylinder 14 of the offset printing methods are cancelled when transferring the ink image from the surface of the blanket cylinder 4 to the surface to be printed on.

Abstract: A registering tool and registering method enables adhering of flexographic printing plates to the cylindrical surface of a rotary press plate cylinder in a manner which assures that the upper and lower edges of the plate are aligned in a strictly parallel relationship with the axis of rotation of the plate cylinder. The tool includes a channel shaped elongated bar having side walls with lower edges which are rested on the cylindrical surface of the cylinder in parallel relationship with the axis of the cylinder. A row of register pin receiving openings extends along a side wall of the bar in parallel relationship with the lower edge of the side wall. The printing plate is temporarily pinned to the bar with register pins which are inserted into registration holes in the printing plate that are equidistant from the upper edge of the plate. A first portion of the plate is then adhered to the cylinder.

Abstract: A method and a device exactly aligning a printing image relative to a geometrically correct print position of a printing machine for printing carriers, for example CDs, which employ use of a printing foil having a hole system which has been aligned relative to the image center and being secured to a printing screen having locating bores which have been aligned relative to the image center and which correspond to locating pins of the printing machine which have been aligned relative to the carrier center.

Abstract: A method for aligning sheet material having a computer generated image thereon with a precut plate stock so that the image is disposed in a predetermined position the plate stock utilizes an alignment fixture. The fixture has registration guides which are matched with indicia on the sheet material to establish the position of the sheet material, and the rigid plate stock is the placed underneath the sheet material on the fixture in a known positional relationship with the guides. The sheet material and the plate stock are then joined together by adhesives or other means without disturbing the established positional relationship of the sheet material relative to the plate stock.

Abstract: An adaptive clamping assembly especially suitable for use in clamping a lithographic plate material around a cylinder. A lead clamp for receiving the leading edge of the plate is fixed along the outer surface of the cylinder parallel to the cylinder's longitudinal axis of rotation. A tail clamp for receiving the trailing edge of the plate is disposed along the outer surface of the cylinder parallel to the lead clamp. The tail clamp is mounted to a take-up assembly that is rotatably mounted within the cylinder bore so that the tail clamp can be selectively positioned along the outer surface of the cylinder relative to the lead clamp. Further rotation of the take-up assembly through rotation of the cylinder tensions the plate around the cylinder for proper imaging or printing.

Abstract: A system for mounting a flexographic printing plate having a registration mark includes a printing plate support surface having a transparent portion formed therein, a plate cylinder, means operably connected to the plate cylinder for positioning the plate cylinder toward the printing plate support surface in a manner to establish a uniform contact line along one side of the printing plate when positioned on the printing plate support surface, a camera operably disposed adjacent another side of the transparent portion for taking a picture of the registration mark of the printing plate when the same is positioned over one side of the transparent portion and a monitor operably connected to the camera having means for viewing the registration mark and position thereof with respect to the camera in another embodiment which includes a pressure roller and method employing the same.

Abstract: There is provided a construction which comprises: a printing plate receiving means that is arranged at a position remote from the periphery of a plate cylinder for supporting a printing plate lock-up hook portion in parallel to the axis of the plate cylinder and as capable of displacement in parallel to that axis; a receiving position determining means for positioning at a predetermined position of the printing plate receiving means the printing plate lock-up hook portion mounted thereon; and a stop position determining means for stopping the printing plate receiving means at a predetermined position relative to a side end surface of the plate cylinder. The invention enables a printing plate being locked up to be positioned with an extremely high precision, yet in a short period of time, corresponding to the position where it is to be locked up, relative to an axially displaced plate cylinder.

Abstract: Machine for mounting flexible printing plates on plate-holder cylinders and for printing proofs with the cylinders thus prepared, the machine being frontally provided with a counterpressure drum and with a beam which are horizontally parallel and move with respect to each other between a mounting position and a printing position. The counterpressure drum can rotate and is covered with a sheet of paper having registration markings. The beam is provided with supports that rotatably support a plate-holder cylinder.