EP1531046B1 - Cylindrical carrier for receiving an exchangeable printing sleeve and method for its manufacturing - Google Patents

Abstract

The cylindrical carrier (1) for a printing cylinder (2) at a printing press, where the cylinder is exchanged by sliding on and off the carrier, has an inner core (10) and a carrier mantle (12) around it. The mantle is sealed at the core at least at the end sides, leaving a space (11) between the mantle and core which can be filled with compressed air from a piston/cylinder unit (17,17'). On a zero pressure, the mantle contracts radially inwards over at least a part of its length, to allow the printing cylinder to be pushed over it and, when the pressure is increased, the mantle expands to hold the printing cylinder with a friction lock. The mantle has an outer elastic cladding of a rubber-type material.

Description

The present invention relates to a cylindrical carrier for receiving a replaceable by axial sliding and peeling hollow cylindrical pressure sleeve and a method for producing the carrier.

Carrier and printing sleeves of the type mentioned are known from practical use in the printing industry. It has been customary to make the pushing and removing the replaceable printing sleeves using a compressed air cushion. For this purpose, the carrier has on its outer circumference a number of small holes which are fed from the interior of the carrier ago with compressed air. The supplied compressed air forms when pushing or pulling the pressure sleeve, an air cushion between the outer periphery of the carrier and the inner circumference of the pressure sleeve. As a result, the pushing or pulling can be done with a small force, because the compressed air cushion ensures a small, but sufficiently large expansion of the inner diameter of the pressure sleeve. When the supply of compressed air is stopped, the air cushion disappears between the carrier and pressure sleeve and the pressure sleeve settles with reduction of its inner diameter frictionally against the outer circumference of the carrier, so that then there is a ready-to-use pressure cylinder.

A disadvantage is to be regarded in this prior art that the usable on the known carrier printing sleeves may only have a very small thickness in order to achieve the required expansion by means of the compressed air cushion in a sufficient extent. In practice, nickel sleeves are used here whose wall thickness is at most about 0.3 to 0.5 mm. This is very limited in the use and in the selection of printing sleeves. In addition, such thin pressure sleeves are very sensitive to mechanical damage.

A carrier according to the preamble of claim 1 is in EP-A-0 736 382 or US-A-4,934,266 disclosed.

For the present invention, therefore, the task of creating a support of the type mentioned above, which offers a greater freedom of choice with respect to the aufziehbaren pressure sleeves on this and can be combined with more stable and therefore insensitive sleeves. At the same time the pushing and pulling the pressure sleeve to the carrier or from the carrier with low forces and thus gently remain possible in particular for the pressure sleeve. Furthermore, a change of the printing sleeve should be possible both inside and outside a printing press. Finally, a good concentricity of the printing cylinder-forming unit of carrier and sleeve should be ensured and a mutual rotation of the carrier and sleeve can be excluded in the printing operation. In addition, a method for producing a suitable carrier is to be created.

The solution of the carrier-related part of this object succeeds according to the invention with a carrier according to claim 1.

Essential to the invention here is the carrier, the component whose outer diameter is changeable for the purpose of pushing on and off of printing sleeves. The pressure sleeves, which are to be used together with the carrier, need not be changeable in their inner diameter. This is advantageously achieved that pressure sleeves with a greater wall thickness and in particular with different wall thicknesses can be combined with a carrier. Thus, with a single carrier, a relatively large range of printing lengths, that is to say, of printing sleeve outer circumferences, can be covered. This offers the advantage for printers that they manage with a relatively small number of carriers, even if they use printing sleeves with many different print lengths, so outer peripheral lengths. The necessary investments for carriers can be greatly reduced in this way. The different print lengths are then simply by correspondingly different thicknesses the sleeves at a few predetermined inner diameters, according to the existing carriers implemented. In handling the carrier according to the invention is at least as comfortable as the previously known carrier with compressed air cushion, so that in this respect no compromises must be made. In addition, it is easily possible to construct the carrier completely rotationally symmetrical, so that a good concentricity of the carrier is guaranteed for themselves and the combination of carrier and pressure sleeve. A mutual rotation of the carrier and pressure sleeve is securely excluded by the frictional engagement between the expanded carrier shell and the pressure sleeve, so that in this respect no problems in the operation of a printing press are to be feared.

In a preferred development of the carrier it is provided that the carrier jacket is connected between the two front ends along a plurality of circumferentially extending connecting lines with the carrier core, wherein the gap space is formed by a plurality of interconnected in the pressure medium permeable connection part-gap spaces. With this subdivision of the gap space into a plurality of partial gap spaces in particular a higher dimensional stability and a higher load capacity of the carrier is achieved without the desired function is limited.

Further, it is preferably provided that the partial gap spaces are formed by running in the circumferential direction of the carrier core recesses, which are bounded by outwardly projecting, extending in the circumferential direction of the carrier core webs. This embodiment has the particular advantage that the carrier remains completely rotationally symmetrical in the circumferential direction, so that no imbalance can arise.

In order to achieve on the one hand a sufficient stability and dimensional stability of the carrier and to use on the other hand for the carrier most cost-effective and easily processable material, it is preferably provided that the carrier core and the carrier shell made of steel or aluminum and by Welds are connected together.

The embodiment of the carrier according to the invention provides that the carrier coat is provided on its outer circumference with an elastic coating. This elastic coating on the outer circumference of the carrier shell provides for an increased frictional engagement between the outer periphery of the coating and the inner circumference of the pressure sleeve and for an improved compensation of deviations of the outer peripheral surface of the carrier from an ideal cylindrical shape. This ensures that deviations of the outer shape of the carrier shell from the cylindrical shape do not affect the outer peripheral surface of the pressure sleeve; Rather, the outer peripheral surface of the pressure sleeve remains completely cylindrical, even if the outer peripheral surface of the support jacket is not a perfect cylinder jacket surface. This ensures a high-quality print result.

Preferably, it is further proposed that the elastic coating is formed by a rubber coating or by a support made of polyurethane or silicone rubber. On the one hand, the coatings mentioned provide the desired increased frictional engagement and, on the other hand, the desired balance of form, the materials being both sufficiently wear-resistant and durable and not requiring much effort for their processing.

Thus, the carrier is not too heavy, is further preferably provided that the carrier core is hollow cylindrical and at its end faces each have an inserted Stirnendstück, each with a Lagerachsstummel and that at least one Stirnendstück a channel for Zuund / or discharge of the pressure medium is performed. Preferably, the channel or channels run concentrically through the Lagerachsstummel, whereby an imbalance is avoided even in a channel guide through the Lagerachsstummel. At the same time there is the possibility to supply pressure medium even in a built-in a printing machine state of the carrier and pressure sleeve or release, which allows the change of a printing sleeve in a built-in a printing machine state of the carrier.

Furthermore, according to the invention, a device for generating and / or changing the pressure of the pressure medium can be arranged in the carrier core, wherein the device can be actuated or switched from outside the carrier core. This embodiment of the carrier offers the particular advantage that it requires no external devices for the generation, supply and discharge of pressure medium. Rather, all the means required for changing the pressure of the pressure medium in the gap space are integrated into the carrier. This makes the use of the carrier possible regardless of whether or not a suitable printing medium source is present in a printing operation.

In this case, the device is preferably a piston-cylinder arrangement accommodated in a front-end end piece or bearing stub axle of the carrier core. This arrangement is designed so that by moving the piston of the piston-cylinder assembly in the gap a selectable pressure of the pressure medium can be adjusted without having to be fed or discharged from the outside pressure medium.

In a further embodiment, the piston is preferably displaceable by an adjusting tool that can be fed from the outside or by an adjusting device that can be shifted from the outside. In the case of a design with an adjustment tool that can be supplied from the outside, a feed opening suitable for this purpose is expediently formed concentrically with the relevant bearing stub axle or front end piece of the carrier core, in order to maintain a rotationally symmetrical structure of the carrier.

With regard to the printing medium used in the carrier, there is a great freedom of choice. The pressure medium may be a gas, preferably air, or a liquid, preferably oil, or a viscous mass, preferably lubricating grease. With all print media, the desired effect, namely the optional enlargement or reduction of the outer diameter of the carrier can be achieved by setting different pressures of the print medium.

The solution of the part of the problem, which deals with a method for producing the carrier, according to the invention succeeds with a method having the features specified in claim 12. According to this claim, the method provides
that a carrier core and a radially surrounding outer support jacket to form a loadable with a pressure medium gap space between the outer periphery of the carrier core and the inner circumference of the carrier shell are at least the front end sealed together and
that is then processed at a pressure p1 of the pressure medium in the gap of the carrier jacket on its outer peripheral surface to a cylindrical shape, after which the carrier jacket at a pressure p0, which is smaller than the pressure p1, a radially inwardly deviating from the cylindrical shape, a low-force pushing and withdrawing a pressure sleeve gestattende form assumes its outer peripheral surface and at a pressure p2, which is higher than the pressure p1, an expanded, partially or fully against the inner periphery of a deferred pressure sleeve frictionally fitting shape of its outer peripheral surface assumes.

Characterized in that the carrier coat is processed at a pressure p1 of the pressure medium in the gap to a cylindrical shape, it is ensured that at the lower pressure p0 the outer circumference of the carrier shell due to the inherent elasticity occupies a radially inwardly deviating from the ideal cylindrical shape. In the state with the pressure p0, therefore, the support jacket is at least over the largest part of its outer peripheral surface in diameter smaller than the inner diameter of an associated pressure sleeve. When a pressure sleeve is pushed onto the carrier and the pressure in the gap space above the pressure p1 is increased to an even higher pressure p2, the outer peripheral surface of the carrier first returns to its cylindrical shape, which it has received at the pressure p1. The further pressure increase no longer ensures a further expansion of the outer circumference of the carrier, but only for an increase in the contact pressure of the outer circumference of the carrier to the inner circumference of the sleeve, since the sleeve is not variable here in terms of their inner diameter. The pressure p2 is suitably determined by tests and selected so high that a sufficiently secure frictional engagement between the carrier and the pressure sleeve is guaran teed, the mutual rotations during operation safely excludes the pressure cylinder formed by the carrier and printing sleeve in a printing press. The pressure p0 may be, for example, the atmospheric air pressure or ambient pressure, whereby the generation of a vacuum, which would be associated with greater technical complexity, is not required. The reduction of the outer diameter of the carrier is due to the elastic properties of the carrier shell without further aids, so that a total of a very simple, yet reliable construction without any joints or other wearing elements is achieved.

Figur 1

einen Träger zusammen mit einer Druckhülse in Ansicht, teils in aufgeschnittener Darstellung, in einer ersten Ausführung,

Figur 2

den Ausschnitt II in Figur 1 in einer vergrößerten Darstellung,

Figur 3

den Träger zusammen mit einer Druckhülse in gleicher Darstellungsweise wie in Figur 1, in einer zweiten Ausführung, und

Figur 4

den Ausschnitt IV in Figur 3 in vergrößerter Darstellung.

Two embodiments of the invention are explained below with reference to a drawing. The figures of the drawing show:

FIG. 1

a carrier together with a pressure sleeve in view, partly in a cutaway view, in a first embodiment,

FIG. 2

the detail II in Figure 1 in an enlarged view,

FIG. 3

the carrier together with a pressure sleeve in the same representation as in Figure 1, in a second embodiment, and

FIG. 4

the detail IV in Figure 3 in an enlarged view.

Figure 1 of the drawing shows partly in view, partly in a sectional view of a carrier 1, which carries a pressure sleeve 2, wherein the unit of carrier 1 and pressure sleeve 2 forms a pressure cylinder.

The carrier 1 consists of a hollow-cylindrical in its basic form carrier core 10, which is surrounded on the outside, leaving a gap 11 by a likewise hollow cylindrical carrier shell 12. The carrier core 10 and the carrier shell 12 are sealed together. As a result, a closed gap 11 is formed.

At both ends of the carrier 1, a respective end face 15, each with an axially outwardly pointing Lagerachsstummel 15 'rotationally inserted into the hollow cylindrical carrier core 10.

The parts 10, 12 and 15 of the carrier 1 are made of metal, in particular steel or aluminum, which ensures the necessary stability and allows easy welding joints.

By the left in Figure 1 Lagerachsstummel 15 'and the associated front end 15 extends axially from the outside coming a bore 16 axially and concentrically toward the interior of the carrier 1, but ends before the hollow interior of the carrier 1 at a distance in front of the axially inner end face of the front end 15. From the inner end of the bore 16 extends a bore 16 'in the radial direction outwards into the gap space eleventh

In the axially inner end region of the bore 16, a piston-cylinder unit 17 is housed. This piston-cylinder unit 17 has an adjustable piston with which the pressure of a in the gap 11 and in the bore 16 'located pressure medium can be changed. To change the position of the piston of the piston-cylinder unit 17 here an adjusting screw 17 'is provided, which in a not specifically shown Thread within the bore 16 is guided. By means of a supplied in the axial direction from the outside through the bore 16 rotary tool, the screw 17 'can be rotated, thereby an axial adjustment of the position of the screw 17' and at the same time the piston of the piston-cylinder unit 17 is effected.

FIG. 2 shows a detail of the structure of the carrier 1 near its left end in FIG. At the lower left in FIG. 2, a part of the front end piece 15 with the bore 16 'running radially therein can be seen. The front end 15 is inserted rotationally in the hollow cylindrical carrier core 10.

The carrier core 10 has on its outer circumference a series of circumferential recesses in the circumferential direction, which are separated by circumferential ridges 13 from each other. In this way, a gap space 11 is formed, which is formed by a series of axially adjacent, separated by the webs 13 part-gap spaces 11 '. The partial gap spaces 11 'are mutually in a permeable to the pressure medium therein communication.

Radially outward follows on the support core 10 and the gap 11 from the partial gap spaces 11 'of the likewise hollow cylindrical support jacket 12. The support jacket 12 is connected along frontally and circumferentially extending welds 14, 14' tightly and firmly connected to the carrier core 10 ,

As shown in FIGS. 1 and 2, the carrier core 10 has a significantly higher material thickness than the carrier shell 12. The carrier shell 12 has a smaller material thickness, which is dimensioned such that, in the case of a change the pressure of the pressure medium in the gap space 11 or in the partial gap spaces 11 'can cause a deformation of the outer peripheral surface 12' of the carrier shell 12.

At a low pressure p0, the outer peripheral surface 12 'of the carrier shell 12 has a shape that deviates radially inwardly at least over partial areas from an ideal cylindrical shape. In this state of the carrier shell 12, the pressure sleeve 2 can be withdrawn with little effort in the axial direction of the carrier 1 or pushed onto the carrier 1.

An increase in the pressure of the pressure medium in the gap 11 to a pressure p2, which is higher than the pressure p0, the support jacket 12 is first expanded so far that it again receives its cylindrical shape of the outer peripheral surface 12 'and then with increasing pressure force to the cylindrical Inner peripheral surface 21 of the pressure sleeve 2 applies.

As shown in drawing figures 1 and 2, the pressure sleeve 2 here has a relatively large thickness, which ensures that the pressure sleeve 2 has a fixed inner and outer diameter, which is not enlarged by forces exerted from the inside. By acting on the gap space 11 with the pressurized pressure medium, a secure frictional engagement between the outer peripheral surface 12 'of the support shell 12 and the inner peripheral surface 21 of the pressure sleeve 2 is effected, so that mutual rotations between the carrier 1 and the pressure sleeve 2 when used in a printing press can not occur.

With a reduction of the pressure of the pressure medium in the gap space 11 to the low pressure p0, the Carrier shell 12 due to its inherent elasticity back to a shape that has a smaller outer diameter, which then pulling off the pressure sleeve 2 and pushing on another pressure sleeve 2 is possible easily and with little effort.

In the case of the second exemplary embodiment of a carrier 1 shown in FIGS. 3 and 4, the carrier corresponds in many parts to the carrier 1 according to FIG. 1 and FIG.

As a different feature, in the carrier 1 according to Figures 3 and 4, a rubber coating 18 on the outer peripheral surface 12 'of the carrier shell 12 is attached. This rubber coating 18 has the purpose, on the one hand to achieve an improved frictional engagement between the outer peripheral surface of the rubber coating 18 and the inner peripheral surface 21 of the pressure sleeve 2 and on the other to provide a surface shape compensation, in the event that the outer peripheral surface 12 'of the support jacket 12 in its expanded Condition has a deviating from an ideal cylindrical shape surface shape. These deviations in shape are then compensated by the rubber coating 18 or a similar elastic coating, so that there is no risk that shape deviations of the outer peripheral surface 12 'of the support shell 12 can propagate to the outer peripheral surface 20 of the pressure sleeve 2. Thus, an absolutely cylindrical surface shape of the outer peripheral surface 20 of the printing sleeve 2 and thus a good printing result with high quality are guaranteed in each case.

In its remaining parts, the carrier 1 and the pressure sleeve 2 correspond to the exemplary embodiment according to FIGS. 1 and 2.

For the preparation of the carrier 1, as shown in the drawing figures 1 to 4, the following manufacturing method is preferably used:

First, the carrier core 10 is provided with the Stirnendstücken 15 and the Lagerachsstummeln 15 '. If necessary, then the machining of the outer peripheral surface of the carrier core 10 to form the gap space 11 and the partial gap spaces 11 'can then take place. Subsequently, the carrier jacket 12 is pushed onto the carrier core 10 and then welded tightly to the carrier core 10 along the welds 14, 14 '(see FIG. 2 and FIG. 4).

Thereafter, the gap space 11 'is filled with pressure medium under a pressure p1, wherein the pressure p1 is greater than the above-mentioned pressure p0 and smaller than the pressure p2 also mentioned above. Due to the pressure p1, the carrier jacket 12, which is exposed to the outside in this processing step and in particular is not surrounded by a pressure sleeve 2, is expanded to a certain extent. In this state, which has been expanded against its own restoring force, the support jacket 12 is machined on its outer circumferential surface 12 'to an exactly cylindrical shape, e.g. by a turning and / or grinding process.

If, after this processing, the pressure of the pressure medium in the gap 11 is lowered to the low pressure p0, the carrier shell 12 returns due to its own restoring force, whereby its outer peripheral surface 12 'assumes a surface shape which deviates radially inwardly from the previously assumed cylindrical shape , At least over most of the outer peripheral surface 12 'thus the diameter of the carrier 1 is reduced and the pressure sleeve 2 can be pushed with little effort in this state on the carrier 1 or withdrawn from the carrier 1 for the purpose of a sleeve change.

Claims (10)

1. Cylindrical carrier (1) for receiving a hollow cylindrical printing sleeve (2) exchangeable by axially pushing it on and pulling it off,
   wherein the carrier (1) comprises a carrier core (10) and a carrier jacket (12) surrounding the latter radially outside;
   wherein the carrier jacket (12) is sealingly connected with the carrier core (10) at least on the front end side;
   wherein a gap space (11) chargeable with a pressure medium is provided between the outer circumference of the carrier core (10) and the inner circumference of the carrier jacket (12);
   wherein, at a first pressure p0 of the pressure medium in the gap space (11), the carrier jacket (12) comprises - at least over one part of its axial length - an outer circumferential surface (12') deviating from the cylinder form radially towards the inside, allowing the printing sleeve (2) to be pushed on and pulled off at a low-force; and
   wherein, at a second, higher pressure p2 of the pressure medium in the gap space (11), the carrier jacket (12) comprises an expanded outer circumferential surface (12')which is adjacent, over the partial or complete surface, in a frictionally locking manner to the inner circumferential surface (21) of a pushed-on printing sleeve (2),
   characterized in that the carrier jacket (12) is provided with an elastic coating (18) on its outer circumferential surface (12').
2. Carrier according to claim 1, characterized in that the elastic coating (18) is formed by rubber coating or by a layer of polyurethane or silicone rubber.
3. Carrier according to claim 1 or 2, characterized in that the carrier jacket (12) between the two front ends of the carrier (1) is connected with the carrier core (10) along a plurality of connecting lines (14, 14') extending in circumferential direction, wherein the gap space (11) is formed by a plurality of partial gap spaces (11') being in a permeable interconnection with each other for the pressure medium.
4. Carrier according to claim 3, characterized in that the partial gap spaces (11') are formed by cavities extending in the circumferential direction of the carrier core (10) and being limited by outwardly protruding fins (13) extending in the circumferential direction of the carrier core (10).
5. Carrier according to any one of the preceding claims, characterized in that the carrier core (10) and the carrier jacket (12) are made of steel or aluminum and connected with each other by weld seams.
6. Carrier according to any one of the preceding claims, characterized in that the carrier core (10) is a hollow cylinder and comprises, on its front faces, one inserted front end piece (15) each with one bearing journal (15') each and that a duct (16, 16') is passed through at least one front end piece (15) for the supply and/or discharge of the pressure medium.
7. Carrier according to any one of the preceding claims, characterized in that a device (17, 17') is provided in the carrier core (10) for producing and/or changing the pressure of the pressure medium, the device being operable or switchable from the outside of the carrier core (10).
8. Carrier according to claim 7, characterized in that the device (17, 17') is a piston cylinder arrangement provided in a front-end front end piece (15) or bearing journal (15') of the carrier core (10).
9. Carrier according to claim 8, characterized in that the piston of the device (17, 17') is slidable by an adjusting tool feedable from the outside or by an adjusting device switchable from the outside.
10. Carrier according to any one of the preceding claims, characterized in that the pressure medium is a gas, preferably air, or a liquid, preferably oil, or a viscous mass, preferably lubricating grease.

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