Patent Application
20120192743
Not applicable.
Not applicable.
In the operation of a rotary offset printing press, freshly printed substrates, such as sheets or web material, are guided by transfer cylinders or the like from one printing unit to another, and then they are delivered to a sheet stacker or to a sheet folder/cutter unit, respectively. As used herein, the term “transfer cylinder” includes delivery cylinders, transfer rollers, support rollers, support cylinders, delivery wheels, skeleton wheels, segmented wheels, transfer drums, support drums, spider wheels, support wheels, guide wheels, guide rollers, and the like.
The ink marking problems inherent in transferring freshly printed substrates have been longstanding. In order to minimize the contact area between the transfer means and the freshly printed substrate, conventional support wheels have been modified in the form of relatively thin disks having a toothed or serrated circumference, referred to as skeleton wheels. However, those thin disc transfer means have not overcome the problems of smearing and marking the freshly printed substrate due to moving contact between the freshly printed substrate and the projections or serrations. Moreover, the attempts to cover the transfer cylinder with a cover material and/or minimize the surface support area in contact with the freshly printed substrate material often resulted in further problems.
Various efforts have been made to overcome the limitations of thin disk skeleton wheels. One of the most important improvements has been completely contrary to the concept of minimizing the surface area of contact. That improvement is disclosed and claimed in U.S. Pat. No. 3,791,644 to Howard W. DeMoore, incorporated by reference herein in its entirety, wherein the support surface of a transfer cylinder in the form of a wide wheel or cylinder is coated with an improved ink repellent surface formed by a layer of polytetrafluoroethylene (PTFE).
During the use of the PTFE coated transfer cylinders in high-speed commercial printing presses, the surface of the coated cylinders must be washed frequently with a solvent to remove any ink accumulation. Moreover, it has also been determined that the PTFE coated cylinders do not provide a cushioning effect and relative movement, which are beneficial.
The limitations on the use of the PTFE coated transfer cylinders have been overcome with an improved transfer cylinder having an ink repellent, cushioning, and supportive fabric covering or the like for transferring the freshly printed sheet. It is now well recognized and accepted in the printing industry world-wide that marking and smearing of freshly printed sheets caused by engagement of the wet printed surface with the supporting surface of a conventional press transfer cylinder is substantially reduced by using the anti-marking fabric covering system as disclosed and claimed in U.S. Pat. No. 4,402,267, by Howard W. DeMoore, entitled “Method and Apparatus for Handling Printed Sheet Material,” the disclosure of which is incorporated herein by reference.
That system, which is marketed under license by Printing Research, Inc. of Dallas, Tex., U.S.A. under the registered trademark SUPER BLUE® includes the use of a low friction coating or coated material on the supporting surface of the transfer cylinder, and over which is loosely attached a movable fabric covering. The fabric covering provided a yieldable, cushioning support for the freshly printed side of the substrate such that relative movement between the freshly printed substrate and the transfer cylinder surface would take place between the fabric covering and the support surface of the transfer cylinder so that marking and smearing of the freshly printed surface was substantially reduced. Various improvements have been made to the SUPER BLUE system, which are described in more detail in U.S. Pat. Nos. 5,907,998 and 6,244,178 each entitled “Anti-Static, Anti-Smearing Pre-Stretched and Pressed Flat, Precision-Cut Striped Flexible Coverings for Transfer Cylinders”; U.S. Pat. Nos. 5,511,480, 5,603,264, 6,073,556, 6,119,597, and 6,192,800 each entitled “Method and Apparatus for Handling Printed Sheet Material”; U.S. Pat. No. 5,979,322 entitled “Environmentally Safe, Ink Repellent, Anti-Marking Flexible Jacket Covering Having Alignment Stripes, Centering Marks and Pre-Fabricated Reinforcement Strips for Attachment onto Transfer Cylinders in a Printing Press”; and U.S. Pat. No. RE39,305 entitled “Anti-static, Anti-smearing Pre-stretched and Pressed Flat, Precision-cut Striped Flexible Coverings for Transfer Cylinders,” each of which is hereby incorporated by reference herein in its entirety. The above cited patents are all owned by Printing Research, Inc. of Dallas, Tex., U.S.A.
In an embodiment, a method of operating a printing press is disclosed. The method comprises installing an anti-marking jacket over a cylinder of the printing press, wherein the jacket comprises a first attachment structure coupled to a gripper edge of the jacket, a second attachment structure coupled to the jacket about one inch away from the first attachment structure towards the tail edge of the jacket, and a third attachment structure coupled to a tail edge of the jacket. Installing the jacket over the cylinder comprises attaching the first attachment structure to a fourth attachment structure coupled to an inner lip of the cylinder at a gripper edge of the cylinder, attaching the second attachment structure to a fifth attachment structure coupled to an outer lip of the cylinder at the gripper edge of the cylinder and outside the printing area of the cylinder, and attaching the third attachment structure to a sixth attachment structure coupled to an inner lip of the cylinder at a tail edge of the cylinder. The jacket is installed tautly between the first attachment structure and the second attachment structure and installed with free play between the second attachment structure and the third attachment structure. The method further comprises, after installing the jacket over the cylinder, printing a plurality of substrates.
In an embodiment, an anti-marking device is disclosed for use in a printing press having a transfer cylinder for transferring a freshly printed substrate. The anti-marking device, comprises an anti-marking jacket comprising a fluoropolymer fabric comprising fluoropolymer threads and a backing fabric that is stiffer and thicker than the fluoropolymer fabric. The fluoropolymer fabric is adhered to the backing fabric to form the anti-marking jacket as a rectangular shape suitable for covering the transfer cylinder. When the anti-marking jacket is installed over the transfer cylinder the fluoropolymer fabric is positioned facing outwards to engage the freshly printed substrate as it is transferred over the transfer cylinder and wherein the anti-marking device is removably attached to the transfer cylinder.
In an embodiment, a method of operating a printing press is disclosed. The method comprises installing a base cover over a cylinder of the printing press. installing a flexible anti-marking jacket over the base cover, and after installing the flexible anti-marking jacket over the base cover, printing a first plurality of substrates. The method further comprises removing the flexible anti-marking jacket from the cylinder, installing a dimensionally stable anti-marking jacket over the base cover, and after installing the dimensionally stable anti-marking jacket over the base cover, printing a second plurality of substrates.
In an embodiment, in a printing press having a transfer cylinder for transferring a freshly printed substrate, an anti-marking device is provided. The anti-marking device comprises a flexible jacket having a first surface and a second surface, each surface having projections projecting from the surface. When the flexible jacket is installed over the transfer cylinder with the second surface positioned facing towards the transfer cylinder the first surface is positioned to engage the freshly printed substrate as it is transferred over the transfer cylinder, and when the flexible jacket is installed over the transfer cylinder with the first surface positioned facing towards the transfer cylinder the second surface is positioned to engage the freshly printed substrate as it is transferred over the transfer cylinder. The anti-marking device is removably attached to the transfer cylinder.
In an embodiment, a method of operating a printing press is disclosed. The method comprises installing a flexible jacket having a first surface and a second surface over a cylinder of the printing press with the second surface facing the cylinder, wherein each of the first surface and the second surface have projections projecting from the surface, and after installing the flexible jacket with the second surface facing the cylinder, printing a first plurality of substrates using the printing press. The method further comprises, after printing the first plurality of substrates, removing the flexible jacket from the cylinder, after removing the flexible jacket from the cylinder, installing the flexible jacket over the cylinder with the first surface facing the cylinder, and, after installing the flexible jacket with the first surface facing the cylinder, printing a second plurality of substrates using the printing press.
In an embodiment, a kit is disclosed. The kit comprises a shipping carton and a plurality of flexible jackets. Each flexible jacket has a first anti-marking surface and a different second anti-marking surface, wherein when the flexible jacket is installed over a cylinder of a printing press with the second anti-marking surface positioned facing towards the cylinder the first anti-marking surface is positioned to engage a freshly printed substrate as it is transferred over the cylinder, wherein when the flexible jacket is installed over the cylinder with the first anti-marking surface positioned facing towards the cylinder the second anti-marking surface is positioned to engage the freshly printed substrate as it is transferred over the cylinder.
These and other features will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings and claims.
For a more complete understanding of the present disclosure, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description, wherein like reference numerals represent like parts.
It should be understood at the outset that although illustrative implementations of one or more embodiments are illustrated below, the disclosed systems and methods may be implemented using any number of techniques, whether currently known or in existence. The disclosure should in no way be limited to the illustrative implementations, drawings, and techniques illustrated below, but may be modified within the scope of the appended claims along with their full scope of equivalents.
In an embodiment, a transfer or other cylinder of a printing press may be at least partially enclosed by an anti-marking jacket that comprises a sheet of fabric comprised of fluoropolymer threads and the sheet of fabric is adhered to a backing fabric. In an embodiment, the backing may be made of a fabric that is stiffer and thicker than the sheet of fabric composed of fluoropolymer threads. The backing may be a woven fabric that is coated with fluoropolymer and that is dimensionally stable. The term dimensionally stable will be described further below, but it may be briefly stated that the stiffness of the backing contributes to the anti-marking jacket retaining shape in the presence of moderate deforming force and restoring to shape after removal of the deforming force. The anti-marking jacket may be attached either tightly or loosely to the cylinder with the fluoropolymer threads facing outwards, away from the cylinder, and the backing fabric facing inwards, towards the cylinder. In an embodiment, a base cover is first installed over the cylinder and the anti-marking jacket is attached over the base cover. The sheet of fabric comprised of fluoropolymer threads may be referred to as a fluoropolymer fabric. In an embodiment, the fluoropolymer fabric comprises at least 80 percent fluoropolymer threads. Said in another way, in an embodiment, the fluoropolymer fabric is woven of threads, where at least 80 percent of those threads are fluoropolymer threads.
In an embodiment, the anti-marking jacket may be attached to a gripper edge of the cylinder such that the anti-marking jacket is held close to the cylinder from a gripper edge of the cylinder to a distance about 1 inch away from the gripper edge, and from this position the anti-marking jacket may be attached loosely until attached at a tail end of the cylinder. In some applications it is desirable to keep the anti-marking jacket close to the cylinder near the gripper edge to avoid the anti-marking jacket bowing outwards and interfering with a mechanical gripper that is part of the cylinder. The loose coupling further along the arc of the outside diameter of the transfer cylinder to the tail edge promotes the anti-marking jacket adapting itself to the movement of the printed substrate to avoid marking the printed substrate.
The anti-marking jacket comprised of the fluoropolymer fabric may hold up better when washed by hot solvents than an anti-marking jacket having glass beads coupled to a dimensionally stable backing material, for example a plastic and/or film backing. Likewise, the anti-marking jacket comprised of the fluoropolymer fabric may hold up better than a flexible jacket woven of natural fibers in the presence of wet printing processes, for example processes involving coatings such as glossy coatings.
In an embodiment, an anti-marking jacket comprised of glass beads or other beads coupled to a dimensionally stable backing material is coupled to the cylinder tautly for a portion of an arc formed by the operator edge and/or the gear edge of the anti-marking jacket beginning from a gripper edge of the cylinder and coupled to the cylinder loosely between the end of this arc to a tail end of the cylinder. Coupling the anti-marking jacket comprised of glass beads or other beads coupled to the dimensionally stable backing material to the cylinder tautly at the leading edge (i.e., gripper edge) of the cylinder may prevent the subject anti-marking jacket from interfering with a gripper mechanism of a transfer cylinder from gripping the leading edge of a printed substrate. The loose coupling further along the arc of the outside diameter of the transfer cylinder to the tail edge promotes the anti-marking jacket comprised of glass beads or other beads coupled to the dimensionally stable backing material adapting itself to the movement of the printed substrate to avoid marking the printed substrate.
In an embodiment, a transfer cylinder or other cylinder of a printing press may be at least partially enclosed by a flexible jacket that is installed over the cylinder, the flexible jacket comprising two anti-marking surfaces, each anti-marking surface having a plurality of projections, for example, a plurality of small beads, small bodies, or other small particles having any of a variety of geometries coupled to the anti-marking surfaces. In some contexts the flexible jacket may be referred to as an anti-marking jacket and may be said to have two anti-marking surfaces. In some embodiments, a cylinder base cover, hereinafter referred to as a base cover, may be installed over the cylinder, for example a low friction anti-static base cover, and the flexible jacket may be installed on the cylinder over the base cover. In other embodiments, however, a base cover may be omitted and the flexible jacket may be installed over the cylinder with no intervening base cover. As substrates are printed and moved through the printing press they are supported, at least in part, by the flexible jacket and more particularly by the plurality of projections from the surface of one of the anti-marking surfaces of the flexible jacket.
The projections project above the anti-marking surface of the flexible jacket and touch the printed substrates in a reduced number of points thereby reducing marking of the substrates through smearing the wet ink. The projections may comprise any of a variety of small bodies or particles of a variety of geometries that are coupled to the anti-marking surface. For example, the small bodies may comprise spherical beads, egg-shaped beads, oblong beads, hemispherical beads, toroidal shaped beads, rounded pyramid shaped beads, polygonal shaped beads, and other shaped beads or particles. In an embodiment, the projections are comprised at least in part of plastic material, glass material, silicon material, and/or ceramic material. Alternatively, the projections may be formed by a process that does not entail coupling beads, bodies, or particles to the anti-marking surface. For example, the projections may be formed by removing material from the anti-marking surface to leave projections separated by gouged out or cut out areas such as holes and/or grooves. Alternatively, the projections may be formed by stippling the anti-marking surface.
Without wishing to be bound by theory, it is thought that the projections may present reduced friction relative to other alternative materials and that this reduced friction may itself contribute to a reduction of marking. In some cases the flexible jacket may be installed tautly over the cylinder, while in other cases the flexible jacket may be installed loosely over the cylinder. While in the following the discussion typically refers to installing the flexible jacket over a transfer cylinder, it is understood that the present disclosure teaches using the flexible jacket installed over other cylinders in a printing press, for example installed over perfector cylinders, over delivery cylinders, and over other cylinders.
As the flexible jacket undergoes a number of printing cycles the surface of the flexible jacket engaging the printed substrates, the outward facing anti-marking surface, and the projections in this anti-marking surface, may wear to a point that the subject flexible jacket may no longer function effectively to reduce marking of substrates. Alternatively or in addition, the flexible jacket may accumulate an undesirable build-up of ink, solvent, or other material such that the subject flexible jacket is no longer functioning suitably. Alternatively, repeated washings may remove enough beads or particles or smooth down projections to render the flexible jacket no longer functional. According to the teaching of the present disclosure, the flexible jacket having two anti-marking surfaces with projections may be removed from the transfer cylinder, reversed, and reattached to the transfer cylinder with the worn anti-marking surface and projections facing the transfer cylinder and with the other anti-marking surface with projections facing outwards to engage the printed substrates. The alternate anti-marking surface with projections, not having been used previously for engaging printed substrates, would be in new condition and hence provide a full service life.
The flexible jacket taught herein may extend the service life of the flexible jacket to twice the normal service life of known flexible jackets having only a single side having projections. Because manufacturing efficiencies may be realized in manufacturing the flexible jacket with two surfaces having projections, as described in more detail below, the two sided flexible jackets may be priced to sell for less than two single sided flexible jackets. Additionally, labor efficiencies may be realized because the press operator need not walk away from the press to retrieve a replacement jacket but instead has, effectively, the replacement already in his or her hands when the worn jacket has been taken off the transfer cylinder. Effectively, the frequency that a replacement flexible jacket would need to be retrieved from stock would be substantially halved. In some circumstances, the two sided flexible jackets may further provide opportunities for reduction of shipping costs and/or packaging costs.
A variety of alternative embodiments of the flexible jacket having two anti-marking surfaces with projections are contemplated, several of which are described further hereinafter. In an embodiment, the flexible jacket may comprise a single sheet of material that has beads, bodies, or particles adhered and/or coupled to two planar surfaces. In an alternative embodiment, the flexible jacket may comprise two sheets of material; beads, bodies, or particles may be adhered to a first planar surface of a first sheet while a second planar surface of the first sheet has no beads, bodies, or particles; beads, bodies, or particles may be adhered and/or coupled to a third planar surface of a second sheet while a fourth planar sheet of the second sheet has no beads, bodies, or particles. The first sheet and the second sheet may be coupled to each other at a tail end and a gripper end of each sheet, with the second planar surface of the first sheet facing the fourth planar surface of the second sheet and with the first planar surface of the first sheet and the third planar surface of the second sheet facing away from each other. In an embodiment, a third sheet of material may be placed between the first and second sheet, for example to serve as packing material to adjust clearance between the transfer cylinder with the flexible jacket installed and the impression cylinder of the printing press or to provide a cushioning effect to the printed substrates as they pass over the flexible jacket. The third sheet may be installed at the time of manufacturing and may be coupled to the flexible jacket or left unattached. Alternatively, the third sheet may be inserted as an option when installing the flexible jacket for the first time over the transfer cylinder. In an embodiment, a plurality of sheets may be installed between the first and second sheet.
In an embodiment, the two anti-marking surfaces or anti-marking sides of the flexible jacket may be different from each other. For example, the first anti-marking surface or side may have projections of a first average size while the second anti-marking surface may have projections of a second average size. For example, the beads on the first anti-marking surface or side may have a first average size that is different from the second average size of the beads on the second anti-marking surface or side. The first anti-marking surface may have projections distributed in a first average density per unit area while the second anti-marking surface may have projections distributed in a second average density per unit area. For example, the beads coupled to the first anti-marking surface may be distributed in a first average density per unit area while the beads coupled to the second anti-marking surface may be distributed in a different second average density per unit area. The first anti-marking surface may have projections, while the second anti-marking surface may comprise one of a fabric woven of cotton threads or other natural fiber threads, a woven fabric coated with fluoropolymer, a fabric woven of fluoropolymer threads, a foil, a film, a chromium coated fabric or film, or other fabric. The use of different anti-marking surfaces in one flexible jacket promotes using the same flexible jacket to perform different printing jobs by reversing the installation of the flexible jacket over the transfer cylinder, for example to accommodate and/or adapt to different substrates. Such a flexible jacket having different anti-marking surfaces may promote reversing the flexible jacket to set-up to run a different print job versus having to leave the press to find and fetch a different flexible jacket, thereby saving time.
Turning now to
In some contexts the projections may be said to face outwards from the first flexible jacket 200 or outwards from the surface 202, 204. It is understood that the projections associated with the first surface 202 may be said to face in a direction opposite from the projections associated with the second surface 204. As shown oriented in
The sheet 206 may comprise a variety of materials. In an embodiment, the sheet 206 may comprise a mylar sheet. In an embodiment, the sheet 206 may comprise a woven fabric sheet, such as a woven cotton sheet and/or a woven cotton canvas sheet. The projections may comprise glass material, ceramic material, silicon material, or other material. In an embodiment, the projections may be less than about 0.025 inches in diameter or that may project less than 0.025 inches above the surface. In an embodiment, the size of the projections on the first surface 202 may be different from the size of the projections on the second surface 204, for example the projections on one surface may be bigger on average than the projections on the other surface. Alternatively, the average density of projections on the first surface 202 may be different than the average density of projections on the second surface 204, for example the number of projections per unit surface area may vary between the surfaces 202 and 204. It is understood that projection manufacturing processes may result in some variation in size among the projections on the first surface 202. Likewise, the manufacturing process may result in some variation in projection density across the first surface 202.
In an embodiment, a protective sheet (not shown) may be detachably adhered to one or both of the surfaces 202, 204. The protective sheet may be adhered by static electricity, by surface attraction, or by another physical mechanism. The protective sheet is water repellant, ink repellant, and/or solvent repellant. In an embodiment, the protective sheet comprises a plastic material such as a plastic sheet or plastic film. When the first flexible jacket 200 is initially attached to the transfer cylinder, the planar side of the first flexible jacket 200 having the protective sheet detachably adhered to it is placed next to or against the transfer cylinder. The protective sheet may protect the surface 202, 204 to which it is attached from solvent and/or ink contamination.
When the surface 202, 204 facing outwards is worn beyond serviceability and/or when the surface 202, 204 suffers from excessive build up of ink and/or solvent, the first flexible jacket 200 is removed from the transfer cylinder, the protective sheet is removed, and the first flexible jacket 200 is reinstalled with the unworn surface 202, 204 facing outwards. The first flexible jacket 200 may be tumbled and then reinstalled. Alternatively the first flexible jacket 200 may be worked and turned and then reinstalled. As is known to those skilled in the art, tumbling means reversing the tail edge with the gripper edge of the first flexible jacket 200 while concurrently making the formerly inwards facing surface become the outwards facing surface. Likewise, as is known to those skilled in the art, worked and turned means keeping the tail edge of the flexible jacket proximate to the tail edge of the transfer cylinder, keeping the gripper edge of the first flexible jacket 200 proximate to the gripper edge of the transfer cylinder, and turning the first flexible jacket 200 to make the formerly inwards facing surface become the outwards facing surface and to make the formerly outwards facing surface become the inwards facing surface.
In an embodiment, for example when the projections on the first surface 202 are different in size and/or density of projections per unit surface area from the projections on the second surface 204, when a different substrate is desired to be printed, the first flexible jacket 200 may be removed from the transfer cylinder, the protective sheet adhered to the second surface 204, for example, facing the transfer cylinder may be removed, the protective sheet may be adhered to the other surface, for example the first surface 202, and the first flexible jacket 200 may be reinstalled over the transfer cylinder with the protective sheet and the first surface 202 facing the transfer cylinder. As different substrates are printed, the first flexible jacket 200 may be flipped back and forth and the protective sheet may be migrated back and forth between the surfaces 202, 204 accordingly.
In an embodiment, a protective sheet may be detachably adhered to both surface 202, 204, which may protect both surfaces 202, 204 of the first flexible jacket 200 during shipping or at other times, for example while the first flexible jacket 200 is stored in inventory. A protective sheet adhered to the first surface 202 may be removed, the first flexible jacket 200 may be attached with the protective sheet adhered to the second surface 204 facing inwards towards the transfer cylinder to protect the second surface against wear and/or build up of ink and/or solvent. In an embodiment, a packing sheet may be installed between the transfer cylinder and the first flexible jacket 200. In an embodiment, the optional packing may be about as large as the width and length of the surfaces 202, 204. Alternatively, in another embodiment, the optional packing may be smaller than the size of the surfaces 202, 204 but at least as large as the width and length of the largest substrate to be printed by the printing press. In an embodiment, a plurality of packing sheets may be installed between the transfer cylinder and the first flexible jacket 200.
In
In an embodiment, the second flexible jacket 210 may have different anti-marking surfaces. In an embodiment, the projections on the third surface 212 may differ from the projections on the fourth surface 214 by being of different average sizes and/or by being joined to the surface 212, 214 in a different density of projections per unit surface area. In another embodiment, the third surface 212 may comprise a plurality of projections that project or protrude, at least partially, from the third surface 212 while the fourth surface 214 and the third sheet 218 may comprise one of a fabric woven of cotton threads or other natural fiber threads, a fabric coated with fluoropolymer, a fabric woven of fluoropolymer threads, a foil, a mylar film, a chromium coated fabric or film, or other sheet of material. The different anti-marking surfaces 212, 214 of these embodiments may permit the second flexible jacket 210 to be used effectively with different printed substrates, for example by reinstalling the second flexible jacket 210 over the transfer cylinder.
In an embodiment, the projections may comprise beads, bodies, or particles that may be coupled to the surfaces 212, 214 as described above with reference to beads, bodies, or particles coupled to the surfaces 202, 204. In an embodiment, the second sheet 216 and the third sheet 218 may be substantially similar to the first sheet 206 described above with reference to
In an embodiment, the third sheet 218 may be different from the first sheet 206 and may not have projections on the fourth surface 214. In an embodiment, the second sheet 216 having projections on the third surface 212 is coupled to a net structure, such that the net structure has slack and is loose when the second flexible jacket 210 is attached to the transfer cylinder with the third surface facing the transfer cylinder. The net structure may comprise a woven cotton fabric, such as the SUPER BLUE system. The net structure may be a fabric woven of cotton threads or other natural fiber threads. The net structure may comprise a woven cotton fabric that is coated with anti-friction material and/or coated with fluoropolymer, for example coated with polytetrafluoroethylene (PTFE) (sold under the trademark TEFLON available from DuPont Corporation and under the trademark XYLAN available from Whitford). The net structure may comprise a woven fabric comprising threads formed of fluoropolymer material. In an embodiment, the net structure is relatively thin and is about as long and wide as the second sheet 216, though the net structure may be somewhat shorter or longer than the second sheet 216. For further details on net structures comprising a woven fabric comprising threads formed of fluoropolymer material, see U.S. patent application Ser. No. 12/343,481, filed Dec. 24, 2008, entitled “Anti-marking Jackets Comprised of Fluoropolymer and Methods of Using in Offset Printing,” by Howard W. DeMoore, et al., which is hereby incorporated by reference in its entirety.
In
The intermediate sheet may be used as packing material, to increase the thickness of the third flexible jacket 230 when attached to a transfer cylinder or to another cylinder of a printing press. Alternatively or in addition, the intermediate sheet may provide some cushioning to the printed substrates as they contact the third flexible jacket 230. In an embodiment, a protective sheet may be detachably adhered to one of the surfaces 232, 234 as described above with reference to
Turning now to
The flexible jacket 250 may have a seventh surface 260 and an eighth surface 262. Initially, the flexible jacket 250 may be installed over a transfer cylinder with the eighth surface 262 facing and/or touching the transfer cylinder and with the seventh surface 260 facing away from the transfer cylinder and/or outwards. The associated printing press may be operated to print a plurality of substrates, the substrates passing over, contacting, and gradually wearing the seventh surface 260 and/or the projections projecting from the surface of the seventh surface 260. In some cases the flexible jacket 250 may have a service life of more than a million substrates. When the seventh surface 260 and/or the projections projecting from the surface of the seventh surface 260 have worn to or beyond the limits of serviceability, the flexible jacket 250 may be removed from the transfer cylinder, flipped over, and reinstalled to the transfer cylinder with the seventh surface 260 (worn surface) now facing and/or touching the transfer cylinder and with the eighth surface 262 facing away from the transfer cylinder and/or outwards. Alternatively or in addition, the flexible jacket may accumulate an undesirable build-up of ink, solvent, or other material such that the subject flexible jacket no longer functions suitably, and the flexible jacket 250 may be removed, flipped, and reinstalled accordingly. If an optional protective sheet is adhered to the eighth surface 262, the protective sheet is removed before operating the printing press with the eighth surface 262 facing outwards. Because the eighth surface 262 has not been contacting substrates and thereby not experiencing wear, the eighth surface 262 is substantially new and may be expected to provide a full service life, for example a million or more printing cycles.
As already discussed above, the flexible jackets may comprise different anti-marking sheets. In an embodiment, at least one of the size of the projections or the density of projections per unit surface area may be different on the two outwards facing surfaces of the flexible jackets 200, 210, 230. The size of projections and/or the density of projections per unit surface area of the surface of the flexible jacket 200, 210, 230 engaging the printed substrate as it passes through a printing press may be selected to be suitable to the characteristics and/or qualities of the subject substrate or of the print image itself. When a first print order is completed and the printing press is being set-up to begin a second print order, the flexible jacket 200, 210, 230 may be removed and reinstalled to present the formerly inwards facing surface to now face outwards and engage the substrates of the second print order.
The size of projections and/or the density of projections per unit surface area of each of the two outwards facing surfaces of the flexible jackets 200, 210, 230 may be selected to provide a compromise solution for a range of different contemplated printing parameters or characteristics. The combination of outwards facing surfaces with different sized projections and/or different densities of projections per unit surface area may reduce set-up time between different print jobs, as the pressman may not need to leave the press to fetch a flexible jacket 200, 210, 230 with suitable projection design. Notwithstanding this contemplated embodiment, other embodiments of the flexible jacket 200, 210, 230 may feature substantially similar projection sizes and/or projection density per unit area on both outwards facing surfaces. Likewise, the flexible jackets 210, 230 may comprise a first anti-marking surface having projections and a second anti-marking surface without projections, for example an anti-marking surface comprising a fabric woven of natural fiber threads, a fabric coated with fluoropolymer, a fabric woven of fluoropolymer threads, a mylar film, a chromium coated fabric or film, or other anti-marking sheet.
The various embodiments of the flexible jacket 250—jacket 200, 210, 230—provide convenience and ease of operation for press operators. When replacing worn flexible jackets 250, the press operator can save time of retrieving a new flexible jacket 250 from storage and disposing a worn flexible jacket 250. Effectively, the press operator will retrieve and dispose the flexible jacket 250 half as often as would be the case with a single sided flexible jacket as known in the prior art. Additionally, it is contemplated that manufacturing processes may realize efficiencies that can support delivering the two sided flexible jacket 250 at a discounted price relative to the price of two separate flexible jackets as known in the prior art.
In different circumstances different flexible jackets 200, 210, 230 may be preferred. For example, in some circumstances the first flexible jacket 200 may be less expensive to manufacture per unit than the second and third flexible jackets 210, 230 but may entail higher initial manufacturing tooling expense. If the production run is expected to be large, it may be expected that the initial manufacturing tooling expense will be overcome by the lower per unit manufacturing cost. On the other hand, if the production run is expected to be low or of uncertain quantity, either the second or third flexible jacket 210, 230 may be preferred. Further, it may be that either the first flexible jacket 200 has longer service life or the second flexible jacket 210 has longer service life, which may further help select which embodiment to manufacture.
In an embodiment, the third sheet 218 and the fourth surface 214 may be shorter than the second sheet 216 and the third surface 212. The attachment mechanism, for example the rod 254, may be coupled to the second sheet 216, but the third sheet 218 may not need to extend completely to the end of the second sheet 216 and is coupled to the second sheet 216. Thus, in some embodiments, the manufacturing of the flexible jackets 210, 230 may consume somewhat less material to manufacture than two separate single sided flexible jackets of the prior art. Likewise, the first flexible jacket 200 may consume half as much sheet material as two separate single sided flexible jackets of the prior art. The manufacture of the flexible jackets 200, 210, 230 may also exhibit labor savings when compared with manufacturing two single sided flexible jackets of the prior art.
Turning now to
The second sheet 1268 may be said to be dimensionally stable. By contrast, a flexible jacket by itself may be readily deformed and may not restore itself to any particular form. The second sheet 1268 resists, to some extent, bending, folding, and deformation and will, to some extent, restore itself to its normal form when a deforming force is removed. To some extent, the second sheet 1268 will act like a spring when flexed and seek to restore its position prior to the flexure. As a result of this dimensional stability, there may be no need to secure the anti-marking jacket 1264 along the operator edge or along the gear edge, excluding attachment points along the gear edge and the operator edge within less than 4 inches of the gripper edge of the cylinder.
Turning now to
In
Attachment structures may be coupled to the transfer cylinder 10 that correspond to the attachment structures 1280, 1282, 1284 of the anti-marking jacket 1264. A fifth attachment structure 1290 may be coupled to an inside lip of the transfer cylinder 10 near the gripper edge of the transfer cylinder 10. An eighth attachment structure 1294 may be coupled to an inside lip of the transfer cylinder 10 near the tail edge of the transfer cylinder 10. In some contexts, the fifth attachment structure 1290 and the eighth attachment structure 1294 may be said to be attached to an inner diameter of the transfer cylinder 10. A sixth attachment structure 1292A and a seventh attachment structure 1292B may be coupled to an outer surface of the transfer cylinder 10, close to the operator edge of the transfer cylinder 10 about one to two inches away from the gripper edge and outside of an area on the transfer cylinder 10 that corresponds to the area Θ when the anti-marking jacket 1264 is installed over the transfer cylinder 10. In an embodiment, the attachment structures 1280, 1282, 1284, 1290, 1292, and 1294 may be corresponding hook and loop material, for example VELCRO. For example, the first attachment structure 1280 may be a strip of female or loop material, and the fifth attachment structure 1290 may be a strip of male or hook material. Alternatively, the attachment structures may be adhesive pads.
As best seen in
Between the second and third attachment structures 1282 and the fourth attachment structure 1284 the anti-marking jacket 1264 may be attached loosely and/or attached with a desirable amount of free play or slack. Without wishing to be bound by theory, it is thought that the slack in the anti-marking jacket 1264—between the attachment structures 1282 and the attachment structure 1284—may contribute to the anti-marking jacket 1264 flexing and adapting to keep pace with the printed substrate as it passes over the rotating transfer cylinder 10. For example, if there is a slight difference between the speed of the transfer cylinder 10 and the printed substrate passing over the transfer cylinder 10, there may be some rubbing that occurs between the transfer cylinder and the printed substrate, which may promote undesirable marking of the printed substrate (e.g., smears). By flexing, the anti-marking jacket 1264 may compensate for slight speed misalignments, avoid rubbing, and thereby avoid undesirable marking of substrates. In some contexts, this adapting may be referred to as the anti-marking jacket 1264 marrying with the printed substrate.
In an embodiment, the first attachment structure 1280 may be coupled to the fifth attachment structure 1290 first. Next, the anti-marking jacket 1264 may be wrapped around or pulled around the transfer cylinder 10 to make the anti-marking jacket 1264 snug or taut, and then the second attachment structure 1282A may be coupled to the sixth attachment structure 1292A and the third attachment structure 1282B may be coupled to the seventh attachment structure 1292B. Next, the anti-marking jacket 1264 may be wrapped around or pulled around the transfer cylinder 10 towards the tail edge of the anti-marking jacket 1264 to initially make the anti-marking jacket 1264 snug, whereby to remove any wrinkles or unevenness that may be present in the anti-marking jacket 1264. Next the tail edge of the anti-marking jacket 1264 may be moved slightly towards the gripper edge of the anti-marking jacket 1264, to provide a desirable amount of slack or free play in the anti-marking jacket 1264, as described further above.
In an embodiment, there may be alignment markings in the outer surface of the anti-marking jacket 1264, for example on the first sheet 1266, that promote providing the free play in uniform increments. Finally, the fourth attachment structure 1284 is coupled to the eighth attachment structure 1294. In other circumstances, other installation methods may be used. For example, in some embodiments, the anti-marking jacket 1264 may be installed without slack or free play. It is understood that a base cover may be attached to the transfer cylinder 10 under the anti-marking jacket 1264. It is understood that the process for attaching the anti-marking jacket 1264 described above may also be employed for attaching the anti-marking jacket with glass beads or other beads coupled to a backing material.
Turning now to
Turning now to
For exemplary purposes, a flexible jacket 100 and the optional base cover will be described with reference to the processing of sheet substrates. However, it will be understood that the principles of the disclosure are equally applicable to web substrates. The flexible jacket 100 may be implemented as any one of the flexible jackets 200, 210, 230, 250 described above. The flexible jacket 100 of the present disclosure and the optional base cover may be used in combination with high-speed printing press equipment of the type used, for example, in offset printing.
Use of the present disclosure, in combination with the transfer cylinder 10 at an interstation transfer position (T1, T3) or at a delivery position (T4) in a typical rotary offset printing press 12, is believed to be readily understandable to those skilled in the art. In any case, reference may be made to U.S. Pat. Nos. 3,791,644 and 4,402,267, which disclose details regarding the location and function of a sheet support cylinder in a typical multistation printing press. The present disclosure may, of course, be utilized with conventional printing presses having any number of printing units or stations.
Turning now to
In an embodiment, the first attachment structure described above may be the first attachment structure 1280 described further above with reference to
Turning now to
At block 438, the flexible anti-marking jacket is removed from the cylinder. At block 440, a dimensionally stable anti-marking jacket is installed over the base cover. At block 442, after installing the dimensionally stable anti-marking jacket over the base cover, a second plurality of substrates is printed. While in the description of the method 400 the flexible anti-marking jacket is installed over the base cover first, in another embodiment, the dimensionally stable anti-marking jacket may be installed over the base cover first, the dimensionally stable anti-marking jacket may then be removed, and the flexible jacket may thereafter by installed over the base cover.
Additionally, the base cover may remain in place and an indefinite number of cycles of installing and removing flexible anti-marking jackets and dimensionally stable anti-marking jackets may occur. In practice, some printing jobs may be better performed using the flexible anti-marking jackets while other different printing jobs may be better performed using the dimensionally stable anti-marking jackets. For example, a wet printing process—i.e., a printing process employing coating the printed substrates—may be unsuitable to the flexible anti-marking jackets, because the flexible anti-marking jackets may become saturated with the wet substances and may ball up and mark the printed substrates. For a wet printing process, the dimensionally stable anti-marking jackets may be preferred as they do not saturate and do not ball up. On the other hand, in a dry printing process the flexible anti-marking jackets may be preferred. The dimensionally stable anti-marking jacket may be either the anti-marking jacket 1264 or the dimensionally stable anti-marking jacket having beads coupled to it described above.
Referring to
As illustrated in
The freshly printed sheets S are transferred to the sheet stacker 18 by a delivery conveyor system, generally designated 30. The delivery conveyor system 30 is of conventional design and includes a pair of endless delivery gripper chains 32 carrying transversely disposed gripper bars, each having gripper elements for gripping the leading edge of a freshly printed sheet S as it leaves the impression cylinder 26 at the delivery position T4. As the leading edge of the printed sheet S is gripped by the grippers, the delivery gripper chains 32 pull the gripper bars and sheet S away from the impression cylinder 26 and transport the freshly printed sheet S to the sheet delivery stacker 18.
Referring to
Referring now to
The hubs 40, 42, and 44 are connected to the cylindrical rim 34 by webs 46, 48 and 50, and support the transfer cylinder 10D for rotation on the delivery shaft 36 of the printing press 12 in a manner similar to the mounting arrangement disclosed in U.S. Pat. No. 3,791,644. In the embodiment shown in
Referring to
The function and operation of the transfer cylinders 10 and associated grippers of the printing units 20 are believed to be well known to those familiar with multi-color sheet fed presses, and need not be described further except to note that the impression cylinder 26 functions to press the sheets against the blanket cylinders 24 which applies ink to the sheets, and the transfer cylinders 10 guide the sheets away from the impression cylinders 26 with the wet printed side of each sheet facing against the support surface of the transfer cylinder 10. Since each transfer cylinder 10 supports the printed sheet with the wet printed side facing against the transfer cylinder support surface, the transfer cylinder 10 is provided with the flexible jacket 100 and the optional base cover as described herein. The flexible jacket 100 and the optional base cover are releasably attached to the transfer cylinder 10 by means for releasably attaching the flexible jacket 100 and the optional base cover to a transfer cylinder 10. In an embodiment shown in
While several embodiments have been provided in the present disclosure, it should be understood that the disclosed systems and methods may be embodied in many other specific forms without departing from the spirit or scope of the present disclosure. The present examples are to be considered as illustrative and not restrictive, and the intention is not to be limited to the details given herein. For example, the various elements or components may be combined or integrated in another system or certain features may be omitted or not implemented.
Also, techniques, systems, subsystems, and methods described and illustrated in the various embodiments as discrete or separate may be combined or integrated with other systems, modules, techniques, or methods without departing from the scope of the present disclosure. Other items shown or discussed as directly coupled or communicating with each other may be indirectly coupled or communicating through some interface, device, or intermediate component, whether electrically, mechanically, or otherwise. Other examples of changes, substitutions, and alterations are ascertainable by one skilled in the art and could be made without departing from the spirit and scope disclosed herein.
This application is a continuation-in-part and claims priority to U.S. patent application Ser. No. 13/018,107 filed on Jan. 31, 2011, entitled “Reversible Anti-marking Jackets and Methods of Using,” by DeMoore, et al., which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 13018107 | Jan 2011 | US |
| Child | 13224394 | US |
