WO1997025209A1 - Printing cylinder with detachable sleeve - Google Patents

Printing cylinder with detachable sleeve Download PDF

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Publication number
WO1997025209A1
WO1997025209A1 PCT/US1996/000541 US9600541W WO9725209A1 WO 1997025209 A1 WO1997025209 A1 WO 1997025209A1 US 9600541 W US9600541 W US 9600541W WO 9725209 A1 WO9725209 A1 WO 9725209A1
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WO
WIPO (PCT)
Prior art keywords
image carrier
carrier sleeve
sleeve
expandable
tubular
Prior art date
Application number
PCT/US1996/000541
Other languages
French (fr)
Inventor
Werner Schulz
Original Assignee
Werner Schulz
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Werner Schulz filed Critical Werner Schulz
Priority to AU51677/96A priority Critical patent/AU5167796A/en
Priority to PCT/US1996/000541 priority patent/WO1997025209A1/en
Publication of WO1997025209A1 publication Critical patent/WO1997025209A1/en

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Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41FPRINTING MACHINES OR PRESSES
    • B41F27/00Devices for attaching printing elements or formes to supports
    • B41F27/10Devices for attaching printing elements or formes to supports for attaching non-deformable curved printing formes to forme cylinders
    • B41F27/105Devices for attaching printing elements or formes to supports for attaching non-deformable curved printing formes to forme cylinders for attaching cylindrical printing formes

Definitions

  • This invention relates to a new and improved printing apparatus using a relatively inexpensive and light weight substantially non-expandable image carrier sleeve having particular utility in combination with an expandable mandrel to hold and frictionally grip the image carrier sleeve.
  • a printing cylinder is utilized for the purpose of carrying the inked image or print for the printing operation.
  • the ink is transferred from a cylindrical surface or cylinder to the paper surface that runs between an aligned impression roller and the printing cylinder.
  • the printing cylinder is used to support a cylindrical sleeve- like printing plate, which may be either flexible or rigid and the printing cylinder is designed to be rotatively mounted in a printing press or machine.
  • Flexographic printing uses similar inks, however, the ink is deposited onto a rubber printing plate or sleeve mounted to a cylinder.
  • Lithography uses a thin image carrier plate, held onto the cylinder with a complicated gripper system that is embedded into the cylinder as is the transfer blanket. Thus a non ⁇ printing gap is necessary and interlocking printing designs with 360° coverage is impossible.
  • a common method of changing printing cylinders is through the use of heat, wherein the cylinders are first heated and then allowed to cool and shrink onto the journals at their ends, thereby forming a frictional fit between the rotating journals and printing cylinder carried thereon.
  • heat is applied to the journal cylinder interface allowing expansion of the cylinder to permit the cylinder to be removed from the journal.
  • the present invention provides: a mandrel having a single circumferential pressure or hydraulic chamber, which extends substantially over the length of the mandrel; does not require seal gaskets between journal sections and the outer expansion jacket or sleeve; groove or contour means for effecting desired expansion/pressure regions or rings about said outer expansion sleeve to thereby provide a substantially uniform outer jacket expansion over a predetermined portion or virtually the full longitudinal length of the jacket with application of hydraulic pressure, which feature not only provides improved frictional gripping of the image carrier sleeve but enables the use of image carrier sleeves having different longitudinal length.
  • a further distinguishing feature of the present inventive system is the use of different outer diameter sized image carrier sleeves, with each having substantially the same inner diameter to enable being selectively slid onto the outer expansion jacket of the present inventive mandrel structure
  • a yet further distinguishing feature of the present invention is the use of various substantially non- expanding materials such as mild steel, thick copper sleeves, carbon fiber sleeves, impregnated paper fiber sleeves or compressed particles, including compressed waste material to form image carrier sleeves.
  • Another distinguishing feature of the present invention is the use of flat sheet metal rolled and joined at its edges to form relatively thin and inexpensive image carrier sleeves which can be ground to a perfectly flat surface for the full 360° or which can be copper plated and ground.
  • Yet another distinguishing feature of the present invention is the substantial elimination of poor print quality resulting from non-uniform expansion and frictional gripping across the juxtaposed surfaces of the expandable mandrel and the inner diameter surface of the image printing sleeve.
  • Another distinguishing feature of the present invention is the relatively greater frictional gripping surface to print image sleeve weight and mass.
  • a printer will require relatively few mandrel type cylinders; the use of a plurality of relatively inexpensive and light weight image carrier sleeves formed of non-expandable material such as carbon fiber or a flat rolled sheet metal formed into a cylinder, each having substantially the same inner diameter; the ability of using various image carrier sleeves having different outer diameters on the same mandrel without installing adjustment collets, etc.; that the shipping costs, of the relatively light weight image carrier sleeves, from the engraver to the printer are substantially reduced or constrained; that the handling and storage difficulties and expenses are curtailed; that any down-time typical with the prior art to replace image carrier sleeves is substantially reduced; that the operational down-time required in the prior art to retrofit the presses with different sized mandrels is substantially, if not fully, eliminated by the use of image carrier sleeves having selectively different thickness in accordance with the present invention; and that frictional gripping is relatively uniformly distributed across the inner diameter surface of the image carrier sleeve.
  • Printing apparatus similar to a so-called gravure, lithographic or flexographic process, of the type having a first tubular cylinder mounted between two journal members and a second tubular cylinder mounted around the first tubular cylinder with a pressure chamber therebetween.
  • the improvement comprises: an expandable mandrel assembly to facilitate or effect a virtually uniform expansion of the second tubular cylinder with hydraulic pressure being applied within said tubular cylinder to an expandable metal wall portion extending between mandrel journals, and an image carrier sleeve formed of non-expandable material such as carbon fiber or from a relatively thin sheet of metal, preferably stainless steel, rolled into a tubular shape of desired diameter and with an inner diameter dimensioned for selectively being slidingly mounted on the second tubular cylinder.
  • An object of the present invention is to provide a new and improved printing apparatus.
  • Another object of the present invention is to provide new and improved light weight image carrier sleeves.
  • Another object of the present invention is to provide a new and improved mandrel assembly having an outer expandable metal tubular cylinder with a longitudinal length substantially or approximately equal to the length of the image carrier sleeve.
  • Another object of the present invention is to provide a mandrel assembly having inner and outer coaxial cylinders with a hydraulic chamber therebetween each being substantially of equal length with the image carrier sleeve.
  • Another object of the present invention is to provide a new and improved mandrel assembly for effecting relatively greater and uniform frictional gripping of the image carrier sleeves across its entire inner circumference and length.
  • Fig. 1 is a longitudinal sectional view through a printing roller according to one embodiment of this invention
  • Fig. 2a is a perspective view of a relatively thin, light weight and flexible flat sheet of metal such as stainless steel used in forming an image carrier sleeve in accordance with an embodiment of the invention
  • Fig. 2b is a perspective view of a relatively thin image carrier sleeve formed from a piece of flat sheet metal as illustrated in Fig. 2a in accordance with the invention
  • Fig. 3a is a perspective view of an image carrier sleeve formed of non- expandable material such as carbon fiber or particles in accordance with a second embodiment of the invention
  • Fig. 3b is a plan end view of the same image carrier sleeve formed of carbon particles/fiber in accordance with the invention.
  • Fig. 4 is a simplified schematic elevational view in cross section of a modified image carrier sleeve.
  • FIG. 1 there is shown an expandable mandrel or printing roller 10 with an image carrier sleeve 61 being mounted thereon in accordance with the present invention.
  • the expandable mandrel 10 generally comprises a pair of spaced end journal members 11, 12, an inner or central sleeve 13 circumferentially mounted at its end regions 14, 15 to a respective end journal 11, 12, an outer expandable sleeve or jacket 16, a pressure chamber 17, a pressure or hydraulic delivery system 18, and one or more expansion grooves or selective expansion means 19.
  • Each end journal member 11, 12 is formed of suitable material such as steel and has a circular outer configuration 20 of predetermined diameter, and a lower circumferential ledge 21.
  • One or both journal members 11, 12 contain hydraulic fluid passageways 22, 23 for containing hydraulic fluid 24. In accordance with this embodiment of the invention, only one end journal member 11 need contain drill holes or throughbores 22, 23 comprising a portion of the hydraulic system 18.
  • an advantage of the present invention is the ability to provide a relatively less complex and less expensive hydraulic throughbores 22, 23 in only one end journal member 11.
  • the mouth end of throughbore 22 contains female threads 25 for matingly receiving the male threads of a hydraulic actuator 26.
  • the hydraulic actuator 26 contains exterior sections such as a hexagonal nut like portion 27 which when manually rotated clockwise and counter-clockwise causes the hydraulic plunger 28 to be selectively displaced inwardly and outwardly.
  • Each end journal member 11, 12 has an outwardly projecting trunnion 29, 30, respectively, which are used to rotatably mount the mandrel 10 onto the printing press (not shown). Since such trunnion 29, 30 mounting members are conventional, detail discussion thereof will be omitted to avoid prolixity.
  • FIG. 1 Another alternative embodiment shown in phantom dotted outline of the hydraulic fluid passageways includes a release valve 32 and connecting throughbore 33, shown in phantom outline.
  • a separate release valve 32 may be superfluous or redundant, since the main adjustment valve 27 may be rotated, for example counter-clockwise, to outwardly displace the plunger and, thereby, reduce or release the hydraulic pressure within the hydraulic system.
  • a separate release valve 32 may be desired for selected operations.
  • FIG. 35 Another alternative embodiment shown in phantom outline 35 is a second hydraulic fluid passageway 36 and adjustment valve 37 provided in the other end journal member 12. In this manner, the press operator can select the most accessible end of the mandrel 10 to effect hydraulic fluid pressure.
  • hydraulic actuator is the use of high pressure grease fittings (not shown) in addition to or in place of the closed plunger system described above in detail.
  • a feature of the invention enables hydraulic pressure adjustment from only one end or, alternatively, either or both end journal members 11, 12.
  • the inner sleeve 13 made of suitable metal, generally defines the longitudinal length 40 of the body portion of mandrel 10.
  • Each end of inner sleeve 13 contains a double ledge arrangement 41, 42 extending circumferentially and dimensioned for matingly engaging the circumferential ledges or platforms 20, 21 provided on each end journal 11, 12, respectively.
  • the inner sleeve 13 is snugly or force fitted onto each end journal member 11, 12, and maybe secured, for example, by weld spots 43, thereto to prevent relative rotation between the constituent mandrel members 11, 12, 13.
  • a body portion of mandrel 10 is configured having a central hollow core 44 and a circular elongate exterior.
  • the outer circumferential surface of inner sleeve 13 is provided with an undercut or alcove 45 to a predetermined depth, for example to a depth of 0.25 mm, and extending laterally or longitudinally across a selected predetermined portion 46 of the main body portion 40.
  • the undercut 45 extends substantially the entire length 40 of the main body portion of mandrel 10, while leaving a raised circumferential outer ring 47, 48 on each end of said inner sleeve 13.
  • alternative embodiments of the invention may utilize varied dimensional undercuts, for example, having a length substantially less than the length of mandrel 10.
  • a throughbore is drilled through inner sleeve 13 in alignment with the throughbore 23 located in end journal member 11. It should be noted that an enlarged throughbore 50 may be drilled into inner sleeve 13 and downwardly a desired depth into end journal member 11 to provide an enlarged interconnected/aligned passageway with passageway 23. A seal type sleeve or gasket like member 52 may be inserted into throughbore 50 to avoid or prevent hydraulic fluid leakage between the juxtapositioned surfaces 20, 41 of the journal member 11 and inner sleeve 13.
  • the outer expandable jacket or second tubular member 16 generafly made of suitable metal, has a wall 72 of selected thickness, and a longitudinal length 40 generally equal to or slightly less than that of inner sleeve 13.
  • Jacket 16 is tubular shaped and has a pair of axially spaced circumferential inner grooves or expansion channels 19 cut into the wall 72.
  • the inner diameter of jacket 16 is slightly greater than the outer diameter of inner sleeve 13, to enable jacket 16 to be slid onto inner sleeve 13.
  • a circumferential welding 57 is provided on each end of jacket 16, to coaxially attach jacket 16 onto and about inner sleeve 13 and to provide circumferential seals therebetween.
  • a circumferential and laterally extending hydraulic expansion or pressure chamber 17 is provided.
  • the inner grooves 19 are dimensioned and located, for example, empirically, in order to effect a generally uniform outward circumferential expansion of jacket 16 with application of hydraulic pressure within chamber 17.
  • An inner groove 19 being approximately a distance 51 of 6 mm from each end of jacket 16, and being 3 mm wide and 0.6 mm deep has been successfully used to effect a substantially uniform expansion in the full region between the inner grooves, with an expansion jacket 16 having a general thickness 55 of 2.3 mm to 3.3 mm.
  • the dimensions of grooves 19 and wall thickness of jacket 16 are subject to variation, it being understood that greater diameters of the jackets will require greater wall thickness and consequently larger grooves. Also more than two grooves may be employed, one possibility being an additional groove in the center of jacket 16 having a selected smaller size than end grooves 19.
  • the hydraulic pressure system 18 generally comprises expansion chamber 17, hydraulic passageways 22, 23 and the adjustment plunger 28, to control the hydraulic fluid pressure therewithin.
  • the image printing sleeve 61 is designed and dimensioned for being slid onto the expansion mandrel 10.
  • the system contemplated in accordance with the present invention comprises an expandable mandrel 10 having an expansion jacket 16 which provides improved frictional gripping over a relatively large axial surface area 46 and the ability of selectively using image printing sleeves 61, 62 having relatively thin 75 wall thickness.
  • hydraulic actuator or plunger means have been described, other means of pressurization of chamber 17 can be employed.
  • the prior art utilized a relatively inflexible, thick walled steel solid construction type cylinder to form a prior art type image printing cylinder (not shown).
  • the machining of the stock tubing requires relatively expensive, laborious and time consuming machine shop labor.
  • the prior art cylinder is relatively heavy, difficult to transport and store and, therefore, greatly increases the cost of each printing job.
  • any denting or out-of-round defects developing in the image printing cyhnder resulted in the costly and time delaying need for the printer to order a replacement cylinder.
  • these ridged thick wall cylinders were required since they were mounted at their end regions such as discussed heretofore in the prior art statement.
  • An important feature of the present invention is the provision of a light weight and flexible cylinder which is substantially of non-expandable material forming the base member of the image carrier sleeve.
  • the non-expandable material may be very thin or may be relatively thick, depending on the material selected.
  • the cylinder 61 is formed from a flat sheet piece of metal, for example, stainless steel, 75 having a predetermined but relatively thin thickness 76.
  • stainless steel has a high modulus of elasticity and is therefore particularly suitable.
  • the length 77 and width 78 are selected to enable the contouring or rolling into a cylinder 61 having a desired length 77 and outer diameter 79.
  • the inner diameter 80 is selected for enabling cylinder 61a to be snugly slid onto the expandable mandrel 16.
  • the length 77 of cylinder 61a is generally selected to equal or be slightly less than the length 40 of mandrel 16.
  • the longitudinal edges 82, 83 of sheet metal 75 are joined together by any suitable manner such as by a weld joint 84, which is filed or ground to a smooth surface.
  • the expandable sleeve 16 of mandrel 10 is designed to radially expand substantially uniformly over its entire length 40, to provide outward pressure in a relatively even manner against the entire inner surface 81 of the substantially non-expandable image printing sleeve 61.
  • the relatively flexible thin wall 76 image printing sleeve 61a is compliantly conformed to and frictionally engaged by the outer surface of jacket 16 with application of hydraulic pressure within chamber 17.
  • the outer peripheral surface of cylinder 61 is plated, for example, with a copper layer (not shown) which may be etched and laminated or treated to form the printing image thereon in conventional manner. Since the plating and etching laminating process used is known in the prior art, a detailed description thereof is omitted.
  • Fig. 3a shows a perspective plan view of an image carrier sleeve 61a having a supporting cylinder 81 formed of a light weight non-expandable material, such as for example, carbon particles or carbon fibers, which is molded into the desired shape having a predetermined length 77, inner and outer diameters 80, 79 respectively.
  • a light weight non-expandable material such as for example, carbon particles or carbon fibers
  • Alternate materials for cylinder 81 are impregnated paper fiber or compressed particles, including compressed waste material.
  • the cylinder 81 has particular benefit in that it is relatively inexpensive to form, is light weight and is not subject to environmentally caused deterioration such as rusting. Also the mentioned materials are substantially non-expandable. As shown in Fig.
  • the carbon cylinder 61b is coated with, for example, a layer of copper 85 which is etched to form the printing image thereon.
  • non-expandable image carrier sleeves comprise a mild steel sleeve which may be constructed as shown in Figs. 2a and 2b and coated with an etchable metal coating, or a relatively thick walled copper sleeve.
  • the removable image carrier sleeve may be provided on one end with a reduced diameter portion as shown in Fig. 4. There the outline of the expandable mandrel 10' is shown in phantom lines.
  • An image carrier sleeve (61b) with substantially non-expandable wall is provided with a curled-in terminating end 86 which is formed to conform to a mating contour of the end of the second tubular cylinder on mandrel 10* .
  • the image carrier sleeve may only be inserted on one end of the mandrel and therefore is properly and uniformly located by sliding the sleeve until end 86 contacts the mandrel end before the mandrel is expanded.

Abstract

A new and improved printing apparatus using an image carrier sleeve (61) which is formed of either carbon fiber/particles or from a relatively thin flat sheet of metal into a cylinder which is substantially non-expandable. The flat sheet of metal, for example, stainless steel or tin, is rolled to form a cylinder of desired diameter and welded together along the longitudinal edges. The weld seam or spots may be filed to have a substantially flat and smooth surface. Also disclosed is a mandrel assembly (10) having an outer metal expansion sleeve member (16) with one or more yield or preferential expansion regions, for example, circumferential grooves for applying pressure to effect uniform outward expansion of said outer sleeve member, so as to frictionally grip the image carrier sleeve.

Description

PRINTING CYLINDER WITH DETACHABLE SLEEVE
TECHNICAL FIELD
This invention relates to a new and improved printing apparatus using a relatively inexpensive and light weight substantially non-expandable image carrier sleeve having particular utility in combination with an expandable mandrel to hold and frictionally grip the image carrier sleeve.
BACKGROUND ART In certain types of printing, for example, gravure printing, a printing cylinder is utilized for the purpose of carrying the inked image or print for the printing operation. The ink is transferred from a cylindrical surface or cylinder to the paper surface that runs between an aligned impression roller and the printing cylinder. The printing cylinder is used to support a cylindrical sleeve- like printing plate, which may be either flexible or rigid and the printing cylinder is designed to be rotatively mounted in a printing press or machine. Flexographic printing uses similar inks, however, the ink is deposited onto a rubber printing plate or sleeve mounted to a cylinder. Lithography uses a thin image carrier plate, held onto the cylinder with a complicated gripper system that is embedded into the cylinder as is the transfer blanket. Thus a non¬ printing gap is necessary and interlocking printing designs with 360° coverage is impossible.
It should be recognized that in the course of various printing jobs or operations, it frequently becomes necessary to replace the image carrier sleeve or cylinder with another. Hitherto, various and relatively expensive methods have been proposed to provide a mandrel structure to enable demountable image cylinders for use in the printing machine.
Not infrequently in printing operations the entire cylinder or mandrel structure is replaced in order to accommodate various circumference image cylinders. Such mandrel replacement is expensive and time consuming. Thus, a long recognized but heretofore unresolved problem of the prior art was the need to have and replace several mandrel type printing rollers to handle image cylinders having different inner diameters, or use of relatively expensive and complex mandrel adapter mechanisms which require valuable machine down¬ time to install.
Another problem of the prior art printing equipment which utilizes such mandrel arrangements is the confinement or limitation to the use of image cylinders being substantially of equal longitudinal dimensions as the printing cylinder or mandrel.
Another long felt but hitherto unresolved problem of the prior art was the generally recognized belief that only relatively expensive, thick walled and heavy image cylinders or image carrier sleeves made from a solid tubular steel or metal could be utilized on a gravure type printing press. This recognition was, in part, justified due to the prior art type expandable mandrels which used frictional gripping at the end regions of the mandrels or journals, as more fully discussed below in the prior art statement. Yet another long felt but unresolved problem of the prior art was the relative great cost of shipping, storing and handling of the prior art (relatively heavy) image cylinders.
A common method of changing printing cylinders is through the use of heat, wherein the cylinders are first heated and then allowed to cool and shrink onto the journals at their ends, thereby forming a frictional fit between the rotating journals and printing cylinder carried thereon. In order to remove the cylinder, heat is applied to the journal cylinder interface allowing expansion of the cylinder to permit the cylinder to be removed from the journal.
One method to eliminate the heating process for removing printing rollers from the mandrel is disclosed in U.S. Patent No. 3,378,902 issued
April 23, 1978 to Rolf Hoexter. This method is a relatively complex, expensive and difficult system for forming pressure plates to carry a radial pressure outwardly to fix the printing cylinder at its spaced end sections to the mandrel by means of two outer collars. As with the other prior art systems, this method requires the use of relatively thick walled and expensive image cylinders to avoid deformation of the cylinder between the pressure plates, i.e., the non-supported or less supported intermediate regions not being frictionally engaged at the mandrel end regions, it being recognized that such deforming or outer diameter variation of the printing cylinder generally would result in non-uniform and unsatisfactory print quality. Another prior art system is described in U.S. Patent No. 4,381,709 issued
May 3, 1983 to Robert Katz, wherein there is shown a three piece mandrel assembly which utilizes a hydraulic system to actuate two end rings to fix in-place a printing cylinder at its longitudinal end sections.
Once again this prior art mandrel assemble requires the use of the prior art type image printing cylinders having relatively thick walls and being expensive to produce, ship, store and handle.
In another prior art U.S. Patent No. 4,651,643 issued March 24, 1987 to Sidney Katz and Robert Katz, relatively expensive and complex adapters for expandable mandrels of printing presses is disclosed. The adapters are formed of annular members which are slidable over each end journal of a multi-piece mandrel and lockable thereto. The adapters each have an outwardly expandable external periphery for gripping and holding a printing cylinder of a diameter larger than that of the mandrel. Thus, this prior art system describes an expensive, complicated and difficult to install system to attempt to adapt a mandrel to an image sleeve having a larger inner diameter than the diameter of the mandrel.
In yet another system as described in U.S. Patent No. 4, 150,622 issued on April 24, 1979 to Joseph A. Stollenwerk, a system employing air pressure is employed in which compressible rings are adapted to be forced outwardly to hold the outer printing cylinder.
Thin flexible metal image carrier sleeves are disclosed in the prior art. U.S. Patent No. 4,656,942 issued April 14, 1987 to Vertegaal et al. shows such a sleeve clamped at its ends and supported over its length by a flexible boot under fluid pressure maintained inside the boot. An image carrier sleeve made by rolling and welding a flat printing plate into tubular or sleeve form is disclosed in U.S. Patent No. 5,379,693 issued January 10, 1995 to Hoffmann et al. This image carrier sleeve is interrupted about its circumference by a longitudinal weld seam which therefore cannot carry a continuous printing design.
Other prior art references of interest are U.S. Patent Nos. 4,812,219 issued March 14, 1989 to Jens E. Sattrup; 4,794,858 issued January 3, 1989 to Sidney Katz; 4,685,393 issued August 11, 1987 to Karl Saueressig; 4,455,903 issued June 26, 1984 to Martin Kesten; 4,386,566 issued June 7, 1983 to Lester I. Moss; 4, 144,813 issued March 20, 1979 to Anthony P. Julian; 3,782,234 issued January 1, 1974 to Alexander Rodach; 3, 146,709 issued September 1, 1964 to W.E. Bass et al. In total contrast to the prior art, the present invention provides a relatively inexpensive, easy to use system which substantially solves many of the above noted prior art recognized problems and, in addition, incorporates structural simplicity and advantageous features hitherto not available.
For example, the present invention provides: a mandrel having a single circumferential pressure or hydraulic chamber, which extends substantially over the length of the mandrel; does not require seal gaskets between journal sections and the outer expansion jacket or sleeve; groove or contour means for effecting desired expansion/pressure regions or rings about said outer expansion sleeve to thereby provide a substantially uniform outer jacket expansion over a predetermined portion or virtually the full longitudinal length of the jacket with application of hydraulic pressure, which feature not only provides improved frictional gripping of the image carrier sleeve but enables the use of image carrier sleeves having different longitudinal length.
A further distinguishing feature of the present inventive system is the use of different outer diameter sized image carrier sleeves, with each having substantially the same inner diameter to enable being selectively slid onto the outer expansion jacket of the present inventive mandrel structure
A yet further distinguishing feature of the present invention is the use of various substantially non- expanding materials such as mild steel, thick copper sleeves, carbon fiber sleeves, impregnated paper fiber sleeves or compressed particles, including compressed waste material to form image carrier sleeves. Another distinguishing feature of the present invention is the use of flat sheet metal rolled and joined at its edges to form relatively thin and inexpensive image carrier sleeves which can be ground to a perfectly flat surface for the full 360° or which can be copper plated and ground.
Yet another distinguishing feature of the present invention is the substantial elimination of poor print quality resulting from non-uniform expansion and frictional gripping across the juxtaposed surfaces of the expandable mandrel and the inner diameter surface of the image printing sleeve.
Another distinguishing feature of the present invention is the relatively greater frictional gripping surface to print image sleeve weight and mass.
Some of the distinguishing functional features of the present invention are: that a printer will require relatively few mandrel type cylinders; the use of a plurality of relatively inexpensive and light weight image carrier sleeves formed of non-expandable material such as carbon fiber or a flat rolled sheet metal formed into a cylinder, each having substantially the same inner diameter; the ability of using various image carrier sleeves having different outer diameters on the same mandrel without installing adjustment collets, etc.; that the shipping costs, of the relatively light weight image carrier sleeves, from the engraver to the printer are substantially reduced or constrained; that the handling and storage difficulties and expenses are curtailed; that any down-time typical with the prior art to replace image carrier sleeves is substantially reduced; that the operational down-time required in the prior art to retrofit the presses with different sized mandrels is substantially, if not fully, eliminated by the use of image carrier sleeves having selectively different thickness in accordance with the present invention; and that frictional gripping is relatively uniformly distributed across the inner diameter surface of the image carrier sleeve.
DISCLOSURE OF THE INVENTION
Printing apparatus similar to a so-called gravure, lithographic or flexographic process, of the type having a first tubular cylinder mounted between two journal members and a second tubular cylinder mounted around the first tubular cylinder with a pressure chamber therebetween. The improvement, in combination, comprises: an expandable mandrel assembly to facilitate or effect a virtually uniform expansion of the second tubular cylinder with hydraulic pressure being applied within said tubular cylinder to an expandable metal wall portion extending between mandrel journals, and an image carrier sleeve formed of non-expandable material such as carbon fiber or from a relatively thin sheet of metal, preferably stainless steel, rolled into a tubular shape of desired diameter and with an inner diameter dimensioned for selectively being slidingly mounted on the second tubular cylinder.
INDUSTRIAL APPLICABILITY An object of the present invention is to provide a new and improved printing apparatus.
Another object of the present invention is to provide new and improved light weight image carrier sleeves.
Another object of the present invention is to provide a new and improved mandrel assembly having an outer expandable metal tubular cylinder with a longitudinal length substantially or approximately equal to the length of the image carrier sleeve.
Another object of the present invention is to provide a mandrel assembly having inner and outer coaxial cylinders with a hydraulic chamber therebetween each being substantially of equal length with the image carrier sleeve.
Another object of the present invention is to provide a new and improved mandrel assembly for effecting relatively greater and uniform frictional gripping of the image carrier sleeves across its entire inner circumference and length.
Other objects, advantages and structural/functional features of this invention will become more apparent from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described with reference to the accompanying drawings, which are illustrative of the preferred embodiments of the invention. Like reference numerals refer to like parts throughout.
Fig. 1 is a longitudinal sectional view through a printing roller according to one embodiment of this invention;
Fig. 2a is a perspective view of a relatively thin, light weight and flexible flat sheet of metal such as stainless steel used in forming an image carrier sleeve in accordance with an embodiment of the invention;
Fig. 2b is a perspective view of a relatively thin image carrier sleeve formed from a piece of flat sheet metal as illustrated in Fig. 2a in accordance with the invention;
Fig. 3a is a perspective view of an image carrier sleeve formed of non- expandable material such as carbon fiber or particles in accordance with a second embodiment of the invention;
Fig. 3b is a plan end view of the same image carrier sleeve formed of carbon particles/fiber in accordance with the invention, and
Fig. 4 is a simplified schematic elevational view in cross section of a modified image carrier sleeve.
BEST MODE FOR CARRYING OUT THE INVENTION
With reference now to Fig. 1, there is shown an expandable mandrel or printing roller 10 with an image carrier sleeve 61 being mounted thereon in accordance with the present invention.
In basic terms, the expandable mandrel 10 generally comprises a pair of spaced end journal members 11, 12, an inner or central sleeve 13 circumferentially mounted at its end regions 14, 15 to a respective end journal 11, 12, an outer expandable sleeve or jacket 16, a pressure chamber 17, a pressure or hydraulic delivery system 18, and one or more expansion grooves or selective expansion means 19. Each end journal member 11, 12 is formed of suitable material such as steel and has a circular outer configuration 20 of predetermined diameter, and a lower circumferential ledge 21. One or both journal members 11, 12 contain hydraulic fluid passageways 22, 23 for containing hydraulic fluid 24. In accordance with this embodiment of the invention, only one end journal member 11 need contain drill holes or throughbores 22, 23 comprising a portion of the hydraulic system 18. It being noted that an advantage of the present invention is the ability to provide a relatively less complex and less expensive hydraulic throughbores 22, 23 in only one end journal member 11. The mouth end of throughbore 22 contains female threads 25 for matingly receiving the male threads of a hydraulic actuator 26. The hydraulic actuator 26 contains exterior sections such as a hexagonal nut like portion 27 which when manually rotated clockwise and counter-clockwise causes the hydraulic plunger 28 to be selectively displaced inwardly and outwardly.
Each end journal member 11, 12 has an outwardly projecting trunnion 29, 30, respectively, which are used to rotatably mount the mandrel 10 onto the printing press (not shown). Since such trunnion 29, 30 mounting members are conventional, detail discussion thereof will be omitted to avoid prolixity.
Shown in phantom dot dash outline is an alternative drill hole(s) 30, 31 and hydraulic actuator 32 placement. It is noted that although the alternative hydraulic passageways 30, 31 embodiment would require somewhat longer drill holes, such placement may be desired for selected purposes and printing operation/equipment without departing from the teachings of this invention.
Another alternative embodiment shown in phantom dotted outline of the hydraulic fluid passageways includes a release valve 32 and connecting throughbore 33, shown in phantom outline. In usual operation a separate release valve 32 may be superfluous or redundant, since the main adjustment valve 27 may be rotated, for example counter-clockwise, to outwardly displace the plunger and, thereby, reduce or release the hydraulic pressure within the hydraulic system. However, it is contemplated that for selected operations a separate release valve 32 may be desired.
Another alternative embodiment shown in phantom outline 35 is a second hydraulic fluid passageway 36 and adjustment valve 37 provided in the other end journal member 12. In this manner, the press operator can select the most accessible end of the mandrel 10 to effect hydraulic fluid pressure.
Another alternative embodiment of the hydraulic actuator is the use of high pressure grease fittings (not shown) in addition to or in place of the closed plunger system described above in detail.
Thus, a feature of the invention enables hydraulic pressure adjustment from only one end or, alternatively, either or both end journal members 11, 12.
The inner sleeve 13, made of suitable metal, generally defines the longitudinal length 40 of the body portion of mandrel 10. Each end of inner sleeve 13 contains a double ledge arrangement 41, 42 extending circumferentially and dimensioned for matingly engaging the circumferential ledges or platforms 20, 21 provided on each end journal 11, 12, respectively. The inner sleeve 13 is snugly or force fitted onto each end journal member 11, 12, and maybe secured, for example, by weld spots 43, thereto to prevent relative rotation between the constituent mandrel members 11, 12, 13. In this manner, a body portion of mandrel 10 is configured having a central hollow core 44 and a circular elongate exterior. The outer circumferential surface of inner sleeve 13 is provided with an undercut or alcove 45 to a predetermined depth, for example to a depth of 0.25 mm, and extending laterally or longitudinally across a selected predetermined portion 46 of the main body portion 40. In the preferred embodiment of the invention the undercut 45 extends substantially the entire length 40 of the main body portion of mandrel 10, while leaving a raised circumferential outer ring 47, 48 on each end of said inner sleeve 13. Notwithstanding, it is contemplated that alternative embodiments of the invention may utilize varied dimensional undercuts, for example, having a length substantially less than the length of mandrel 10. A throughbore is drilled through inner sleeve 13 in alignment with the throughbore 23 located in end journal member 11. It should be noted that an enlarged throughbore 50 may be drilled into inner sleeve 13 and downwardly a desired depth into end journal member 11 to provide an enlarged interconnected/aligned passageway with passageway 23. A seal type sleeve or gasket like member 52 may be inserted into throughbore 50 to avoid or prevent hydraulic fluid leakage between the juxtapositioned surfaces 20, 41 of the journal member 11 and inner sleeve 13.
The outer expandable jacket or second tubular member 16, generafly made of suitable metal, has a wall 72 of selected thickness, and a longitudinal length 40 generally equal to or slightly less than that of inner sleeve 13.
Jacket 16 is tubular shaped and has a pair of axially spaced circumferential inner grooves or expansion channels 19 cut into the wall 72. The inner diameter of jacket 16 is slightly greater than the outer diameter of inner sleeve 13, to enable jacket 16 to be slid onto inner sleeve 13. A circumferential welding 57 is provided on each end of jacket 16, to coaxially attach jacket 16 onto and about inner sleeve 13 and to provide circumferential seals therebetween. In this manner, a circumferential and laterally extending hydraulic expansion or pressure chamber 17 is provided. The inner grooves 19 are dimensioned and located, for example, empirically, in order to effect a generally uniform outward circumferential expansion of jacket 16 with application of hydraulic pressure within chamber 17. An inner groove 19 being approximately a distance 51 of 6 mm from each end of jacket 16, and being 3 mm wide and 0.6 mm deep has been successfully used to effect a substantially uniform expansion in the full region between the inner grooves, with an expansion jacket 16 having a general thickness 55 of 2.3 mm to 3.3 mm. The dimensions of grooves 19 and wall thickness of jacket 16 are subject to variation, it being understood that greater diameters of the jackets will require greater wall thickness and consequently larger grooves. Also more than two grooves may be employed, one possibility being an additional groove in the center of jacket 16 having a selected smaller size than end grooves 19. It should be recognized that other means, for example, varying the channel depth dimensions or thickness of the central area or metallurgical makeup of the expansion jacket 16, may be utilized to effect a virtually uniform or desired circumferential outward expansion of jacket 16 across a longitudinal expanse substantially co-extensive with the main body of mandrel 10, in accordance with one feature of this invention. The hydraulic pressure system 18 generally comprises expansion chamber 17, hydraulic passageways 22, 23 and the adjustment plunger 28, to control the hydraulic fluid pressure therewithin.
The image printing sleeve 61, described in greater detail hereafter, is designed and dimensioned for being slid onto the expansion mandrel 10. The system contemplated in accordance with the present invention comprises an expandable mandrel 10 having an expansion jacket 16 which provides improved frictional gripping over a relatively large axial surface area 46 and the ability of selectively using image printing sleeves 61, 62 having relatively thin 75 wall thickness. As will be appreciated, while hydraulic actuator or plunger means have been described, other means of pressurization of chamber 17 can be employed.
With particular reference now to Figs. 2a and 2b, a first preferred embodiment of the invention will now be described in greater detail.
As previously pointed out, the prior art utilized a relatively inflexible, thick walled steel solid construction type cylinder to form a prior art type image printing cylinder (not shown). The machining of the stock tubing requires relatively expensive, laborious and time consuming machine shop labor. The prior art cylinder is relatively heavy, difficult to transport and store and, therefore, greatly increases the cost of each printing job. In addition, any denting or out-of-round defects developing in the image printing cyhnder resulted in the costly and time delaying need for the printer to order a replacement cylinder. Typically, these ridged thick wall cylinders were required since they were mounted at their end regions such as discussed heretofore in the prior art statement. An important feature of the present invention is the provision of a light weight and flexible cylinder which is substantially of non-expandable material forming the base member of the image carrier sleeve. The non-expandable material may be very thin or may be relatively thick, depending on the material selected.
The cylinder 61 is formed from a flat sheet piece of metal, for example, stainless steel, 75 having a predetermined but relatively thin thickness 76. Stainless steel has a high modulus of elasticity and is therefore particularly suitable. The length 77 and width 78 are selected to enable the contouring or rolling into a cylinder 61 having a desired length 77 and outer diameter 79. The inner diameter 80 is selected for enabling cylinder 61a to be snugly slid onto the expandable mandrel 16. The length 77 of cylinder 61a is generally selected to equal or be slightly less than the length 40 of mandrel 16. The longitudinal edges 82, 83 of sheet metal 75 are joined together by any suitable manner such as by a weld joint 84, which is filed or ground to a smooth surface.
The expandable sleeve 16 of mandrel 10 is designed to radially expand substantially uniformly over its entire length 40, to provide outward pressure in a relatively even manner against the entire inner surface 81 of the substantially non-expandable image printing sleeve 61. The relatively flexible thin wall 76 image printing sleeve 61a is compliantly conformed to and frictionally engaged by the outer surface of jacket 16 with application of hydraulic pressure within chamber 17.
In this manner, warping, bends, dents and out-of-round deformity which may have occurred during handling, shipping and storage are substantially and without additional cost remedied. Thus, the relatively costly problem of cylinder defects inherent in the prior art system cylinders are substantially eliminated.
In addition, the cost of manufacture, shipment, handling and storing the image printing sleeve 61 are substantially reduced in accordance with the present invention.
The outer peripheral surface of cylinder 61 is plated, for example, with a copper layer (not shown) which may be etched and laminated or treated to form the printing image thereon in conventional manner. Since the plating and etching laminating process used is known in the prior art, a detailed description thereof is omitted.
This opportunity is taken to point out another advantage of the present system over the prior art. Due to the relatively flexible characteristic of the thin image carrier sleeve 61 and the relatively uniform outward locking pressure on the inner wall surfaces of the image printing sleeve 61, the quaHty of the printing is substantially improved. This improvement results from the fact, in contradiction to the prior art, that the inner wall surfaces are engaged and supported by an expandable metal tubular cylinder 16 substantially over the full length 77 of the image printing sleeve 61 as a result of increased frictional (area) engagement.
With reference now to Figs. 3a and 3b, another preferred embodiment of the invention will be described in detail.
Fig. 3a shows a perspective plan view of an image carrier sleeve 61a having a supporting cylinder 81 formed of a light weight non-expandable material, such as for example, carbon particles or carbon fibers, which is molded into the desired shape having a predetermined length 77, inner and outer diameters 80, 79 respectively. Alternate materials for cylinder 81 are impregnated paper fiber or compressed particles, including compressed waste material. The cylinder 81 has particular benefit in that it is relatively inexpensive to form, is light weight and is not subject to environmentally caused deterioration such as rusting. Also the mentioned materials are substantially non-expandable. As shown in Fig. 3b, the carbon cylinder 61b is coated with, for example, a layer of copper 85 which is etched to form the printing image thereon. Further examples of non-expandable image carrier sleeves comprise a mild steel sleeve which may be constructed as shown in Figs. 2a and 2b and coated with an etchable metal coating, or a relatively thick walled copper sleeve.
Of particular utility in the removable image carrier sleeve is the ability to provide a continuous printing design. The sleeve may be provided on one end with a reduced diameter portion as shown in Fig. 4. There the outline of the expandable mandrel 10' is shown in phantom lines. An image carrier sleeve (61b) with substantially non-expandable wall is provided with a curled-in terminating end 86 which is formed to conform to a mating contour of the end of the second tubular cylinder on mandrel 10* . With this device, the image carrier sleeve may only be inserted on one end of the mandrel and therefore is properly and uniformly located by sliding the sleeve until end 86 contacts the mandrel end before the mandrel is expanded.
While the principles of this invention have been described above in connection with specific embodiments, it is to be understood that this description is merely by way of example and not as a limitation as to the scope of the invention.

Claims

1. Printing apparatus comprising an image carrier sleeve in combination with an expandable printing mandrel having particular utility for uniformly supporting the image carrier sleeve, comprising: a first tubular cyhnder (13) having axially-spaced end portions each defining a respective cylindrical opening of predetermined dimension; a pair of axially-spaced journal members (11, 12) each having an outer cylindrical portion received within a respective one of said cylindrical openings and affixed to the respective tubular end portion; a second tubular cylinder (16) having an inner diameter (69) greater than the outer diameter (70) of said first tubular cyhnder and being mounted thereon and affixed thereto, and actuatable pressure means (18) having a circumferential pressure chamber (17) defined between circumferentially spaced wall portions (45, 72) of said first and second tubular cylinders, characterized in that: said first tubular cyhnder having a relatively uniform intermediate expandable metal wall portion (72) axially extending (46) between said journal members; and said image carrier sleeve (61, 61a, 61b) having a substantially non-expandable wall (76) with an axial length (77) approximately co-extensive with the expandable metal wall portion (46) of said second tubular cylinder for being snugly and slidingly mounted thereon, whereby substantially the entire axial length of said image printing cyhnder being subjected to a radially directed, frictionally engaging and circumferentially outwardly defining force.
2. An image carrier sleeve in combination with an expandable printing mandrel as in claim 1, wherein: the image carrier sleeve (61) is formed from a relatively thin sheet of stainless steel which is coated with a layer of copper that may be etched to form the desired printing image.
3. An image carrier sleeve in combination with an expandable printing mandrel as in claim 1, wherein: the image carrier sleeve (61a) is formed from carbon fibers, said sleeve being laminated with a metal layer suitable for being etched.
4. An image carrier sleeve in combination with an expandable printing mandrel as in claim 1, wherein: the image carrier sleeve (61a) being formed from carbon particles and an outer copper laminated layer deposited thereon.
5. An image carrier sleeve in combination with an expandable printing mandrel as in claim 1, wherein: the image carrier sleeve (61a) is formed from impregnated paper fiber, said sleeve being laminated with a metal layer suitable for being etched.
6. An image carrier sleeve in combination with an expandable printing mandrel as in claim 1, wherein: the image carrier sleeve (61a) is formed from compressed particles including compressed waste material, said sleeve being laminated with a metal layer suitable for being etched.
7. An image carrier sleeve in combination with an expandable printing mandrel as in claim 1, wherein: the image carrier sleeve (61a) is formed from mild steel, said sleeve being coated with a metal layer suitable for being etched.
8. An image carrier sleeve in combination with an expandable printing mandrel as in claim 1, wherein: the image carrier sleeve (61) being formed from a thick copper sleeve.
9. An image carrier sleeve and expandable printing mandrel as in claim 1 , wherein: the second tubular cyhnder contains a metal wall portion (72) defining two or more axially-spaced circumferential groove means (19) for facilitating said relatively uniform intermediate expandable metal wall portion (46) thereof.
10. An image carrier sleeve and expandable printing mandrel as in claim 1, wherein: the pressure chamber (17) being substantially defined between said first tubular cyhnder and the inner diameter wall portion (72) of said second tubular cyhnder, and extending axially (46) between said journal members.
11. An image carrier sleeve in combination with an expandable printing mandrel as in claim 1, wherein: one end (86) of said image carrier sleeve (61b) is formed with a diameter less than that of the second tubular cyhnder, and conformed to fit against the end of the second tubular cyhnder, whereby the image carrier sleeve may be properly and consistently located on the printing mandrel.
PCT/US1996/000541 1996-01-08 1996-01-08 Printing cylinder with detachable sleeve WO1997025209A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
AU51677/96A AU5167796A (en) 1996-01-08 1996-01-08 Printing cylinder with detachable sleeve
PCT/US1996/000541 WO1997025209A1 (en) 1996-01-08 1996-01-08 Printing cylinder with detachable sleeve

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US1996/000541 WO1997025209A1 (en) 1996-01-08 1996-01-08 Printing cylinder with detachable sleeve

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WO1997025209A1 true WO1997025209A1 (en) 1997-07-17

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001039973A1 (en) * 1999-12-03 2001-06-07 Macdermid Graphic Arts S.A. Sleeve comprising a layer for being fixed on a metal support roll
EP1679190A1 (en) 2005-01-10 2006-07-12 Steinemann Technology AG Printing device with cylinder
JP2009285880A (en) * 2008-05-27 2009-12-10 Universal Seikan Kk Method of taking out sleeve printing plate, sleeve printing plate, plate cylinder, and printer

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1021067A (en) * 1962-12-01 1966-02-23 Hans Saueressig Printing roller

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1021067A (en) * 1962-12-01 1966-02-23 Hans Saueressig Printing roller

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001039973A1 (en) * 1999-12-03 2001-06-07 Macdermid Graphic Arts S.A. Sleeve comprising a layer for being fixed on a metal support roll
FR2801833A1 (en) * 1999-12-03 2001-06-08 Rollin Sa A SLEEVE COMPRISING A SOLIDARIZATION LAYER ON A CYLINDER METAL SUPPORT
EP1679190A1 (en) 2005-01-10 2006-07-12 Steinemann Technology AG Printing device with cylinder
JP2009285880A (en) * 2008-05-27 2009-12-10 Universal Seikan Kk Method of taking out sleeve printing plate, sleeve printing plate, plate cylinder, and printer

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