Abstract: A plate cylinder has formed therein a groove extending parallel to the cylinder axis and having a depth direction thereof set at an angle to a plane tangent to the plate cylinder at the groove, so that the opposite sides of the groove are at acute and obtuse angles, respectively, to that plane. For use with this plate cylinder, the printing plate has two staggered series of spaced lugs formed on a pair of meeting edges of its image-bearing major part. The two series of lugs are bent at approximately the same acute and obtuse angles, respectively, to the major part as the opposite sides of the groove are to the tangential plane. For mounting the plate to the cylinder, the acute-angled series of lugs of the plate are first inserted in the groove in the cylinder so as to hook these lugs onto the acute-angled leading side of the groove. Then the plate is wrapped around the cylinder by rotating the same in a prescribed direction.

Abstract: The object of the invention is an integrated guiding device for positioning and cutting with the help of a cutting tool, a printing plate (16) on a sleeve (10) or on a printing cylinder, particularly for flexography, said sleeve or cylinder comprising an external coating (24) adapted to be deeply machined, characterized in that it comprises at least one longitudinal guide (30) along a generatrix, and/or a peripheral guide, along a circumference, provided within a matrix of material of high hardness, embedded in the thickness of said external coating. The invention also comprises the sleeve or cylinder provided with this device.

Abstract: A method and apparatus for fitting a printing plate to a plate cylinder where the printing plate is bent into a circular shape and fixed in this form by leading and trailing legs of the plate being firmly connected to each other. The printing plate shaped in this way is subsequently axially pushed onto the plate cylinder from the free side of the plate cylinder.

Abstract: A clamping device for firmly clamping a cylinder packing or covering on a printing machine cylinder, the clamping device having a clamping seat, a clamping jaw cooperating therewith, and an eccentric shaft, includes a support wherein the eccentric shaft and the clamping jaw are jointly mounted, the support being adjustable alternatively into a first support position and into a second support position relative to the clamping seat; and a printing machine having at least one clamping device with the foregoing construction.

Abstract: The clamping device is used to adjust at least one register element in a printing machine. The device has an upper clamping rail, to which the register element is fixed. The upper clamping rail can be moved in a guide and fixed in position in order to adjust the register element.

Abstract: A blanket-mounting mechanism includes a dragging shaft, a rotating device, a correction device, and a deflection suppression device. A dragging-shaft accommodation bore extends axially through a blanket cylinder. A blanket insertion groove extends axially on the outer circumferential surface of the blanket cylinder and extends radially to the dragging-shaft accommodation bore. The dragging shaft has a blanket-end reception groove formed on the outer circumferential surface and adapted to receive one end of a blanket. The dragging shaft is inserted into the dragging-shaft accommodation bore with an appropriate gap maintained therebetween and is supported rotatably. The rotating device is disposed at the side of one end face of the blanket cylinder and is connected to the dragging shaft. The correction device is disposed at the side of the other end face of the blanket cylinder and is able to grip/release the dragging shaft so as to adjust the angular position of the dragging shaft.

Abstract: A device for changing printing forms on form cylinders of rotary printing machines, having a pivotable surface for guiding the printing forms to be changed, the printing forms being grippable at an underside thereof, includes a pivotable printing-form table to which a separately actuatable contact member is assigned, the contact member being throwable onto a surface of a printing form disposed on the printing-form table for positioning the printing form in any selective position, a method for changing printing forms, and a printing unit including the changing device.

Abstract: In a printing machine, a tip end of a print sheet 22, which is transferred from a paper feed section 5 synchronously with rotation of a printing drum 16 and a pressure drum 17, is clamped by a sheet clamp section 21 at a rotation clamp position upstream of a press portion on which the printing drum 16 and the pressure drum press each other. The print sheet 22 thus clamped is transferred along an outer peripheral surface of the pressure drum 17 and pressed against a stencil sheet on the press portion. Then, printing is done. The printing machine is provided with a sheet clamp guide member 30 guiding the tip end of the print sheet 22, which is transferred from the sheet feed section 5, to a position on which the print sheet 22 is abutted on a sheet abutment face 21a of the sheet clamp section 21 located at the rotation clamp position.

Abstract: The present invention provides an input roller system for displacing a printing plate toward and against a plurality of registration pins located on an external drum of an imaging system. The input roller system deskews the printing plate relative to the registration pins.

Abstract: In the present invention, a blanket cylinder for a printing press is made up of a shaft roller and a cylindrical blanket capable of being attached and detached freely to and from the shaft roller. The cylindrical blanket comprises an elastic layer formed integrally with a cylindrical sleeve by winding and bonding a sheet-form elastic member on and to the outer peripheral surface of the sleeve, the elastic layer having a gap extending in the axial direction formed between both ends in the circumferential direction of the sheet-form elastic member; and a separation preventive member for preventing both ends in the circumferential direction of the sheet-form elastic member from being separated from the sleeve, the separation preventive member being embedded in the gap so as to be thinner than the thickness of the sheet-form elastic member to form a groove in the outer peripheral surface of the elastic layer.

Abstract: A groove for receiving opposite end edges of an object such as a printing plate is formed in a printing cylinder in the vicinity of the outer circumferential surface thereof such that the groove extends from an axially extending anchor-shaft hole toward the outer circumferential surface of the cylinder body, thereby opening at the outer circumferential surface. One wall surface of the groove intersects, at an acute angle, with a tangent plane passing through a line of intersection between the wall surface and the outer circumferential surface of the printing cylinder, thereby forming an edge together with the outer circumferential surface of the printing cylinder. The first end edge portion of the object is bent at an acute angle, and the second end edge portion of the object is bent at an obtuse angel which is substantially the supplementary angle of the acute angle.

Abstract: A blanket cylinder for use in offset lithography in combination with a blanket assembly having a rubber blanket bonded to a major portion of a metal-made carrier sheet. The carrier sheet has a first end portion bent at an angle to the major portion to provide a first flange, and a second end portion bent twofold to provide a second flange at an angle to the major portion, and a rim at an angle to the second flange. The blanket cylinder has formed therein an undercut groove in which the flanges of the blanket carrier sheet are to be received, with the first flange in positive engagement with one longitudinal edge of the groove.

Abstract: A device for correcting a skew of a skewed printing plate on a plate cylinder of a rotary printing machine, comprising a front clamping bar for holding a leading edge of the printing plate; and a rear clamping device including at least one rear clamping bar for holding a trailing edge of the printing plate, an axially guided lower bar and a pivoting strip mounted so as to be pivotable about a first pivot point on said lower bar; the front clamping bar being pivotable about a second pivot point disposed approximately centrally in an axial extent of a cylinder channel formed in the plate cylinder, and the at least one rear clamping bar being mounted on the pivoting strip so that the at least one rear clamping bar is pivotable in circumferential direction about a third pivot point.

Abstract: A plate inserting apparatus in a rotary printing press for inserting a plate into a plate fixing unit of a plate cylinder includes a plate holder, a cover, and a first reference pin. The plate holder moves between a first position where the plate holder holds the plate and a second position where the held plate is inserted into the plate fixing unit of the plate cylinder. The cover selectively opens and closes a plate insertion side of the plate cylinder. The first reference pin is fixed to the cover to position the plate before held by the plate holder when the plate holder is located at the first position.

Abstract: A recording drum has a clamp groove extending in its circumferential direction formed on its outer peripheral surface. A plurality of front end clamps are attached to the outer peripheral surface of the recording drum. Rear end clamps are attached so as to be movable and so as to be fixable along the clamp groove on the outer peripheral surface of the recording drum. A recording head is disposed ahead of the recording drum, and a clamp driving device is disposed behind the recording drum. The clamp driving device comprises a first driving device for fixing the front end clamps and fixing and releasing the rear end clamps and a second driving device for releasing the front end clamps. The front end clamps and the rear end clamps reliably fix a front end and a rear end of a plate to the outer peripheral surface of the recording drum by a reaction force produced by a spring and a centrifugal force produced by the rotation of the recording drum.

Abstract: A plate material tensioning and advancement mechanism is disposed in parallel relation to a cylinder, such as a plate cylinder of a printing press, so as to separate the plate material into distinct printable sections. The plate material tensioning and advancement mechanism assists in supplying tension to the plate material via a tensioning roll during printing operation and assists in winding fresh plate material about the cylinder during advancement operation by reducing the tension on the plate material and by optionally applying tangential force to the plate material via a winding roll.

Abstract: A printing press comprises a pair of left- and right-frames, a first printing plate guiding device provided at a location near a lower plate cylinder, swingably supported so as to be moved between a guiding position for guiding a new printing plate supplied to a lower plate cylinder or a discharged printing plate discharged from the lower plate cylinder and a shelter position released from the lower plate cylinder, a second printing plate guiding device provided at a location near the lower plate cylinder, swingably supported so as to be moved between a guiding position for guiding the new printing plate or the discharged printing plate and a shelter position released from the lower plate cylinder and a safety cover swingably supported so as to be moved between a closing position for closing at least one part of a space formed between the left- and right-frames and a releasing position for releasing the space.

Abstract: A printing plate changing device prevents a new printing plate from being damaged even if an abnormal attachment has occurred during/before attaching the printing plate on a plate cylinder. Various sensors detect a rear end of the new printing plate located near an extrusion member when a phase of the lower plate cylinder forwardly rotating is positioned at a predetermined position, an actuator of the lower printing plate holding device is extended by a control device in accordance with a signal from the sensors to release a hook from an engaged pin. A claw portion is rotated by force energized by a spring to advance into a stored portion. The claw portion of the hook is engaged with the rear end of the new printing plate so that the new printing plate can be returned into the stored portion by extending the actuator.

Abstract: A sheet-fed printing press is provided to shorten the operation time thereof for feeding the printing plate on the plate cylinder in a printing operation without the tail edge of the printing plate clamped. For this purpose, the sheet-fed printing press is operable in the standard-sized printing plate feeding mode and the shorter-sized printing plate feeding mode. When the shorter-sized printing plate feeding mode is selected, the plate cylinder is rotated in the forward direction with the leading edge of the printing plate clamped by the first clamp device, so that the printing plate is wound around the plate cylinder. In this operation, the second clamp device is not actuated.

Abstract: A universal edge strip is secured to both leading and trailing edges of a flexographic carrier sheet. A universal edge strip assembly includes the universal edge strip and a retaining clip. The universal edge strip includes a first pair of parallel walls connected to a center web which define a first deep slot or channel. The universal edge strip also includes a second pair of walls connected to the same center web which defines a second J-shaped shallow slot or channel. The first slot receives the carrier sheet which is secured to the universal edge strip by conventional means. One of the walls adjacent the second shallow slot includes a projection or J-shape which defines a throat adjacent the opposite wall. A U-shaped retaining clip is received within the second shallow slot in the universal edge strip at one end of the carrier sheet and is hooked to an undercut lip on the flexographic printing cylinder. As noted, both leading and trailing edges of the carrier sheet include a universal edge strip.

Abstract: A container for a printing blanket comprises a cassette of dimensions sufficient at least to contain a printing blanket in wound form. The cassette comprising a casing of generally cylindrical shape having a longitudinal opening for sheet-form egression of a printing blanket from within the cassette. In one preferred embodiment, the cassette has a pressure slide attached to or integral therewith adjacent to the longitudinal opening, for pressing a printing blanket on a press cylinder when the blanket is fed onto the cylinder. The cassette is employed in the manipulation of large adhesive-backed printing blankets for web-feed offset printing presses.

Abstract: A system for loading and clamping one or more plates onto the cylindrical surface of a rotatable drum, such as used in a platesetter for printing, and for unloading the plates from the drum. The system is characterized by clamps that are movable over the surface, preferably along circumferential tracks, enabling the attachment of multiple plates, end-to-end and/or side-by-side, each plate having any of a wide range of sizes. The clamps are preferably of the dynamic type, whereby the clamping force increases with rotational speed. Also disclosed is a method for mounting and unmounting plates, using the movable clamps, such that allows flexible and convenient arrangement of loading- and unloading stations.

Abstract: The invention relates to an apparatus for correctly registering mounting of a printing plate. Task of the invention is to provide an apparatus to control the correctly registered position of a printing plate, which can be realized with simple means and can withstand abrupt load changes of the printing plate. The task is solved according the invention by inserts allocated to registering elements, which are contacting the printing plate electrically isolated from the registering elements and are connected to a control unit.

Abstract: A method for applying a gravure printing plate to a gravure printing drum including: applying a release liner on the gravure printing drum, wherein a release layer of the release liner faces away, from the drum, applying a double-sided adhesive foil to the gravure printing drum, wherein the two edges of the adhesive foil overlap, cutting through the overlapping edges of the adhesive foil and through the release liner, removing the release liner and attaching the two cut edges of the adhesive foil to the drum, applying a release liner on the gravure printing drum, wherein a release layer of the release liner faces towards the adhesive foil, applying the gravure printing plate onto the double-sided adhesive foil, wherein the two edges of the plate overlap in the area of the release liner, cutting through the overlapping edges of the gravure printing plate and through the release liner; and removing the release liner and attaching the two cut edges of the gravure printing plate to the adhesive foil.

Abstract: The present invention provides a media handling system for an imaging system, such as an external drum platesetter. Separate input and output trays are provided, thereby allowing pre-staging of a second printing plate while a first printing plate is being imaged. The input tray is positioned over the output tray to reduce the floor space (i.e., footprint) of the imaging system.

Abstract: A plate-mounting member to be attached to a plate front end of a flexible plate in order to mount said flexible plate having a plurality of fixing holes onto a plate cylinder including a plate front end clamp mechanism having upper and lower teeth and at least two positioning pins disposed between upper and lower teeth, said plate-mounting member comprising a base and a plurality of fixing pins disposed on said base to be respectively inserted into said plurality of fixing holes formed in said plate front end, wherein said base is to be attached to said positioning pins disposed in said plate front end clamp mechanism to thereby position said plate front end. Also disclosed are method and apparatus for mounting a flexible printing plate.

Abstract: For use in a printing press cylinder (1) of the type having in its surface an axial cavity (2) produced for location of a lock-up device for a printing blanket on the cylinder, there is provided an adaptor fillet to adapt the cylinder for accommodation of a printing blanket without a lock-up device, the adaptor fillet comprising a fillet (3) of a shape for insertion into the cavity so as to bridge the cavity flushly with the cylinder surface periphery, said fillet having an arcuately curved bridge surface (10) of the same radius of curvature as that of the cylinder and having in its bridge surface a longitudinal slit (11) for guidance of a knife edge. In a preferred embodiment of the invention, the fillet is in two-part form, consisting of a lower part (4) securable in the cavity by a threaded fastener entering the cavity base, and an upper part (5) securable to the lower part and providing the arcuately curved bridge surface.

Abstract: A device for fastening flexible printing plates to a plate cylinder of rotary printing machines is provided. The plate cylinder has a channel, a channel gap, and a bore. The channel accommodates bent ends of the printing plate. The bore in the channel is axially parallel to the plate cylinder. Two segmented shafts are arranged pivotally in the bore and have leaf springs which are fastened to the segmented shafts. The leaf springs can be brought into contact with the ends inserted into the channel. The channel has at least one lateral recess or cut out in an area which connects the bore radially to a channel gap on the periphery of the plate cylinder, and is at a distance form the channel gap. The end of the printing plate which is bent approximately at a right angle, is provided with a shaped element projecting in the direction of recesses in the channel. The shaped element of the end inserted into the channel can be moved into the recess by bringing the leaf springs into pressure contact with the bent end.

Abstract: A stencil sheet retaining device includes a clamping plate (44) for retaining an end portion of the stencil sheet (M), and a flapper member (49) for drawing out the end portion of the stencil sheet (M) from the clamping plate (44) side. A first contact piece (48) attached to the clamping plate (44) and a second contact piece (51) attached to the flapper member (49) are pressed due to the profiles of the cam grooves (56a, 56b) of a movable cam member (56) according to the rotary position of the rotary cylindrical drum (6), so that the clamping plate (44) and the flapper member (49) can be opened and the open angle of the clamping plate (44) and the flapper member (49) can be adjusted.

Abstract: A retainer for holding a printing plate to the cylindrical surface of a vacuum drum has a curved surface which conforms to and seals against the cylindrical surface of the drum. The retainer is held in place by pressure differential. An edge portion of a printing plate is received below a lip which extends along the retainer. The retainer is light in weight and therefore does not significantly unbalance the drum even if it is not always in the same position on the drum. The retainer is also inexpensive to manufacture and less likely than prior art clamps to cause damage if it fails.

Abstract: A system for loading and clamping one or more plates onto the cylindrical surface of a rotatable drum, such as used in a platesetter for printing, and for unloading the plates from the drum. The system is characterized by clamps that are movable over the surface, preferably along circumferential tracks, enabling the attachment of multiple plates, end-to-end and/or side-by-side, each plate having any of a wide range of sizes. The clamps are preferably of the dynamic type, whereby the clamping force increases with rotational speed. Also disclosed is a method for mounting and unmounting plates, using the movable clamps, such that allows flexible and convenient arrangement of loading- and unloading stations.

Abstract: A device for clamping the trailing edge of a printing plate in a plate cylinder of a rotary printing machine includes a torsion bar disposed in a cylinder gap formed in the plate cylinder and extending in axial direction thereof, clamping elements affixed to the torsion bar and cooperating with holding elements for clamping the printing plate, and actuators provided on both sides of the plate cylinder for stretching the printing plate in axial direction. The torsion bar is of bipartite construction, and the actuators, respectively, are mounted so as to be displaceable axially independently of one another.

Abstract: Freshly printed sheets are transferred from one printing unit to another by transfer cylinders each having an ink repellent, electrically conductive, striped flexible jacket covering that is movable relative to the sheet support surface of the transfer cylinder. The jacket covering is made of a flexible fabric material that is pre-stretched, pressed flat, cut to size and treated with an ink repellent compound and is also treated with an anti-static ionic compound or is otherwise rendered electrically conductive by one or more conductive strands. Electrostatic charges carried by the freshly printed sheets are discharged through the ink repellent, electrically conductive, flexible jacket covering into the grounded transfer cylinder. A low friction, electrically conductive cylinder base covering that includes center alignment marks is secured to the transfer cylinder for engaging the flexible jacket covering.

Abstract: A device for fastening flexible printing plates to a plate cylinder of rotary printing machines having a channel in the plate cylinder which accommodates bent ends of the printing plate. A bore in the channel is axially parallel to the plate cylinder and has two segmented shafts arranged pivotably therein. Leaf springs are each fastened to the segmented shafts and can be brought into contact with the ends of the printing plate inserted into the channel. A region radially connects the bore to a channel gap on the periphery of the plate cylinder. The channel has lateral recesses at a distance from the channel gap and, the approximately rectangularly bent ends of the printing plate are equipped with shaped elements which project into the channel in the direction of the recesses. The shaped elements of one or both ends inserted into the channel can be moved into the recesses by bringing the respective leaf springs into contact while bending the ends.

Abstract: A leading edge side part 10a of a printing plate 10 can easily be inserted into a gap L1 formed between a plate guide 15 positioned adjacent to positioning pins 11 and a leading edge side clamping base 51 because the gap L1 is formed in a thickness slightly thicker than the printing plate 10. Restoring force caused by flexure of the printing plate 10 allows the leading edge side part 10a thereof being inserted into the gap L1, the restoring force being generated when a tail edge side part 10b of the printing plate 10 is in contact with a contact member 2.

Abstract: A device in an axially extending tension channel on the circumferential surface of a cylinder for fastening a flexible plate on the cylinder periphery. The leading edge of the plate is held by a leading edge fastening device in the channel, and the trailing edge is held by a trailing edge fastening device in the channel. The leading edge fastening device is a start hook-in bar which the leading edge of the plate engages. The trailing edge fastening device is formed by an end hook-in bar which is engaged by the trailing edge of the plate. The end hook-in bar projects tangentially from a tensioning shaft which is rotatable to set the tension of the plate without means to apply a clamping load. Various devices for fastening and adjusting the leading and trailing edges of the plate are disclosed.

Abstract: The present invention is a one-piece molded strap used to secure a printing plate to a drum of a high speed roller machine. The one-piece molded strap comprises a one-piece molded body comprising an elastomeric portion, a rigid latch portion, and a rigid elongated body portion. The rigid latch portion is integrally formed with and chemically bonded to one end of the elastomeric portion. The rigid elongated body portion is integrally formed with and chemically bonded to the other end of the elastomeric portion. The one-piece molded strap is formed by an injection molding process wherein the material composition of the rigid latch portion and the rigid elongated body portion are compatible with the material composition of the elastomeric portion.

Abstract: Flexible plates are placed on a plate cylinder by inserting leading and trailing plate suspension legs into cooperating slits. Each of the plate suspension legs is pushed into the receiving slit by an insertion device that uses plate front and rear insertion sliders. These two insertion sliders each act as a guide for the adjacent slider.

Abstract: A system for loading and clamping one or more plates onto the cylindrical surface of a rotatable drum, such as used in a platesetter for printing, and for unloading the plates from the drum. The system is characterized by clamps that are movable over the surface, preferably along circumferential tracks, enabling the attachment of multiple plates, end-to-end and/or side-by-side, each plate having any of a wide range of sizes. The clamps are preferably of the dynamic type, whereby the clamping force increases with rotational speed. Also disclosed is a method for mounting and unmounting plates, using the movable clamps, such that allows flexible and convenient arrangement of loading- and unloading stations.

Abstract: A device for fastening a machine plate in an offset press is disclosed. The machine plate fastening device may be gripped by a plate lock-up device on the offset press. The device has a plate and a leaf spring, the plate having fastening pins and the leaf spring holding the machine plate on the pins. The leaf spring has holes corresponding to the fastening pins. Also disclosed is a joint plate which can be attached to fix the fastening device at an appropriate angle on the offset press.