BRIEF DESCRIPTION OF THE DRAWINGS
Further advantages and advantageous embodiments and developments of the invention are explained with reference to the following Figures and the description thereof. In the Figures:
FIG. 1 shows two states of a plate-form object that can be shaped to form a packing sleeve according to the invention,
FIG. 2 shows an embodiment of a packing sleeve according to the invention on a printing unit cylinder, and
FIG. 3 shows an embodiment of a packing sleeve according to the invention that receives a cylinder packing.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows two states of a plate-form object 30, preferably of steel or aluminium, which can be shaped to form a packing sleeve 10 according to the invention (see FIGS. 2 and 3). The plate-form object 30 includes a region 38 with an area 20 of incisions 22. The incisions 22 can be apertures or cut-outs. Preferably, these incisions 22 are continuous, that is to say, the incisions 22 cut through the plate-form object 30, preferably in the form of slots or elongated slits. The incisions 22 are arranged along lines, incisions on adjacent lines being arranged offset or alternating with respect to one another. The left-hand side of FIG. 1 shows the plate-form object 30 in the resting state 32 or force-free state. In this situation, the plate-form object 30 has a specific dimension and a specific resilient behaviour, which are contingent upon its form and its material. The right-hand side of FIG. 1 shows the plate-form object 30 in a second state 34, in which a force 36, a tensile force, acts on the plate-form object 30 with a force component perpendicular to the run of the incisions 22. By virtue of the incisions 22 in the area 20, which have an orientation and hence an anisotropy owing to their shaping, the resilient behaviour of the plate-form object 30 changes, preferably anistropically, compared with an object of corresponding form without incisions. Perpendicular to the run of the incisions 22, a force 36 causes a dilatation of the plate-form object 30. This deformation or elongation is resilient; on cessation of the force effect, the plate-form object 30 reverts to its resting state 32, as shown on the left-hand side of FIG. 1. To cite an example: a packing sleeve according to the invention of 35 mm thick steel, in which alternating incisions of a length of 200 mm are arranged in twenty lines spaced 10 mm apart, can be extended by 0.4 mm with 35 daN per metre of the packing sleeve width (in the direction of the figure axis).
FIG. 2 shows an embodiment of a packing sleeve 10 according to the invention on a printing unit cylinder 12. Without loss of generality in respect of the topology and the geometry of a packing sleeve according to the invention, the embodiment shown here is a packing sleeve having slits passing right through it. The packing sleeve 10 has an outer lateral surface 14 and has a figure axis 16, which in the mounted state coincides with the axis of rotation of the printing unit cylinder 12. On the outer lateral surface 14 there is an area 20 containing a number of incisions 22. The incisions 22 are arranged along lines substantially parallel to the figure axis 16. Adjacent lines in the circumferential direction have alternating incisions 22, so that a netlike structure of webs between the incisions 22 is created. The packing sleeve 10 can be tensioned in the peripheral direction 24. A slot 18 serves to receive edges of a cylinder packing (see FIG. 3). In the area 19 surrounding the slot 18 the packing sleeve has no incisions 22.
For the sake of completeness, it should be mentioned that to change the fixing state of the packing sleeve, preferably for mounting or demounting, the printing unit cylinder of this embodiment has a device for tensioning the packing sleeve in the peripheral direction, the device not being more specifically shown here although it is known from the prior art. In the relaxed state, the packing sleeve can be moved relatively easily relative to the printing unit cylinder. As an alternative to this solution, changing of the fixing state, that is, mounting and demounting of the packing sleeve, can be facilitated by stretching the packing sleeve, preferably an embodiment of the packing sleeve having an area of incisions that do not cut completely through the packing sleeve from the outer to the inner lateral surface, by means of compressed air issuing from the printing unit cylinder, so that the packing sleeve is readily displaceable relative to the printing unit cylinder. Such devices are also known from the prior art.
As already mentioned, the packing sleeve according to the invention may be manufactured from a lightweight material, for example aluminium, so that manipulation thereof is simplified. Furthermore, recesses may be present, preferably on the inner lateral surface of the packing sleeve, so that the weight of the packing sleeve is reduced, without altering the stiffness.
FIG. 3 is a schematic view relating to an embodiment of a packing sleeve 10 according to the invention which receives a cylinder packing 26, for example, a printing plate or a printing blanket (rubber blanket). The cylinder packing 26 is held by clamping and stretching the packing sleeve 10 in the peripheral direction 24. The cylinder packing 26 has bent-over edges 28, which engage in the slot 18. The slot 18 widens prism-form from the outer lateral surface 14 inwards towards the figure axis 16. The lateral faces of the slot are thus undercut or angled; the lateral faces and the outer lateral surface enclose an acute angle, so that when a force is effective in the peripheral direction 24, the cylinder packing 26 is stretched in the circumferential direction.
In summary it should again be emphasised that the packing sleeve according to the invention, in particular a metallic packing sleeve, preferably advantageously may have a resilience adapted in the circumferential direction to the tension forces, whilst the regions of the outer lateral surface that are subjected to load transmission and to wear and tear experience no weakening or reduction in rigidity by virtue of the hardness and the stiffness of the material used, in particular the metal used.
LIST OF REFERENCE NUMERALS
10 Packing sleeve
12 Printing unit cylinder
14 Outer lateral surface
16 Figure axis
18 Slot
20 Area
22 Incision
24 Peripheral direction
26 Cylinder packing
28 Edge
30 Plate-form object
32 Resting state
34 Second state
36 Force
38 Region
Patent Application
20080041254
